JP2015060728A - Transparent electrode and organic electroluminescent element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent electrode which has both sufficient conductivity and optical transparency by improving smoothness of an electrode surface, and to provide an organic EL element which suppresses a decrease in rectification ratio, occurrence of leakage, and the like by using the transparent electrode and achieves improvement in yield and reliability.SOLUTION: A transparent electrode 10 of the present invention includes: a transparent substrate 11; a compound layer 1a which is configured to contain an alkali metal or an alkaline earth metal and oxygen and is provided on one main surface side of the transparent substrate 11; and a metal layer 2 which is composed of silver or an alloy consisting mainly of silver and is provided on the one main surface side of the transparent substrate 11 via the compound layer 1a.

Description

  The present invention relates to a transparent electrode and an organic electroluminescence element using the transparent electrode.

  An organic electroluminescence element (hereinafter also referred to as “organic EL element”) is a thin-film type all-solid structure in which an organic thin film layer (single layer portion or multilayer portion) containing an organic light-emitting substance is formed between an anode and a cathode. It is an element. When a voltage is applied to such an organic EL element, electrons are injected from the cathode into the organic thin film layer and holes are injected from the anode, and these are recombined in the light emitting layer (organic light emitting substance-containing layer) to generate excitons. The organic EL element is a light-emitting element using light emission (fluorescence / phosphorescence) from these excitons, and is a technology expected as a next-generation flat display and illumination.

  Furthermore, since an organic EL element using phosphorescence emission from an excited triplet, which can realize a luminous efficiency of about 4 times in principle in comparison with an organic EL element using fluorescence emission, has been reported from Princeton University, Starting with the development of materials that exhibit phosphorescence at room temperature, research and development of light-emitting element layer configurations and electrodes are being carried out around the world.

  As described above, the phosphorescence emission method is a method having a very high potential. However, in an organic EL device using phosphorescence emission, a method for controlling the position of the emission center is significantly different from that using fluorescence emission. How to recombine within the light emitting layer to stabilize the light emission is an important technical issue for capturing the efficiency and lifetime of the device.

  Therefore, in recent years, a multilayer stacked device having a hole transport layer located on the anode side of the light emitting layer and an electron transport layer located on the cathode side of the light emitting layer in a form adjacent to the light emitting layer is well known. Yes. In addition, a mixed layer using a phosphorescent compound as a light emitting dopant and a host compound is often used for the light emitting layer.

  On the other hand, from the viewpoint of materials, there is great expectation for creating new materials for improving device performance.

  In addition, the emitted light generated in the light emitting layer of such an organic EL element is taken out through the anode or the cathode. For this reason, at least one of the anode and the cathode is configured as a transparent electrode.

As the transparent electrode, indium tin oxide is _{(SnO 2 -In 2 O 3:} : Indium Tin Oxide ITO) oxide semiconductor-based material such as is commonly used, low by laminating the ITO and silver Studies aiming at resistance have also been made (see, for example, Patent Document 1 below). However, since ITO uses rare metal indium, the material cost is high, and it is necessary to perform annealing at about 300 ° C. after film formation in order to reduce resistance, but it is not suitable for a resin substrate. Further, when used as an electrode of an organic EL element, the surface smoothness of the electrode is insufficient, and a treatment such as polishing is necessary. Therefore, a configuration in which a metal material such as silver having high electrical conductivity is thinned, or a configuration in which conductivity is ensured with a thinner film thickness than silver alone by mixing aluminum with silver (for example, see Patent Document 2 below) is proposed. Has been.

  Moreover, as a transparent electrode, the structure which thinned silver etc. by providing metal materials, such as silver, adjacent to the organic layer comprised using the nitrogen compound, and the structure which used this transparent electrode for the organic EL element ( For example, the following patent document 3) has been proposed.

JP 2002-15623 A JP 2009-151963 A International Publication No. 2013/073356

  However, even if the organic layer is made of a metal material such as silver adjacent to the transparent electrode having a structure in which silver or the like is thinned, the surface of the transparent electrode has insufficient smoothness. It was difficult to improve the permeability. Moreover, when this transparent electrode was used for the bottom emission type | mold of an organic EL element, it was confirmed that the smoothness of the surface of a transparent electrode is inadequate, a fall of a rectification ratio, generation | occurrence | production of a leak, etc. arise. Therefore, in such an organic EL element, improvement in reliability is demanded while suppressing a decrease in rectification ratio and occurrence of leakage due to the smoothness of the transparent electrode and improving yield.

  Therefore, the present invention provides a transparent electrode that has both sufficient conductivity and light transmittance by improving the smoothness of the electrode surface, and by using this transparent electrode, the rectification ratio is reduced, leakage occurs, etc. Is provided, and an organic EL element in which the yield is improved and the reliability is improved is provided.

  The above-mentioned problem according to the present invention is solved by the following means.

  The transparent electrode of the present invention comprises a transparent substrate, an alkali metal or alkaline earth metal, and oxygen, a compound layer provided on one main surface side of the transparent substrate, and silver or silver as a main component. It is comprised with an alloy and has the metal layer provided in the one main surface side of the transparent substrate through the compound layer.

  Moreover, the organic EL element of the present invention is characterized by having the transparent electrode having the above-described configuration.

  In the transparent electrode configured as described above, a metal layer composed of silver or an alloy containing silver as a main component is provided on a compound layer composed of alkali metal or alkaline earth metal and oxygen. ing. As a result, silver oxide is formed between the compound layer and the metal layer, and the smoothness of the surface is improved by the interaction between the silver oxide and the silver or the alloy containing silver as a main component. It is possible to form a metal layer that is thin but has a uniform thickness and high surface smoothness. Accordingly, it is possible to achieve both sufficient conductivity and light transmittance by improving the smoothness of the electrode surface.

  In particular, the organic EL device of the present invention has such a transparent electrode, and as described above, the surface smoothness of the transparent electrode is improved, so that the reduction of the rectification ratio in the device and the occurrence of leakage are suppressed. can do. Accordingly, it is possible to improve the yield as well as the reliability.

  As described above, according to the present invention, it is possible to achieve both sufficient conductivity and light transmittance by improving the smoothness of the electrode surface in the transparent electrode. Further, since the organic EL element of the present invention is configured using such a transparent electrode with improved smoothness of the electrode surface, it is possible to improve the yield as well as the reliability. Become.

It is a cross-sectional schematic diagram which shows the structure (it has a laminated body of 2 layer structure) of the transparent electrode which concerns on 1st Embodiment. It is a cross-sectional schematic diagram which shows the structure (it has a laminated body which provided the organic layer) of the transparent electrode which concerns on 2nd Embodiment. It is a cross-sectional schematic diagram which shows the structure (it has a laminated body which provided the scattering layer) of the transparent electrode which concerns on 3rd Embodiment. It is a cross-sectional schematic diagram which shows the structure of the organic EL element of 4th Embodiment. It is a cross-sectional schematic diagram which shows the structure whose counter electrode of the organic EL element of 4th Embodiment is a laminated body of 2 layer structure. It is a cross-sectional block diagram explaining the organic EL element produced in the Example. It is a graph which shows the relationship between the effective unshared electron pair content rate [n / M] of an organic layer, and the sheet resistance of the transparent electrode laminated | stacked on the organic layer.

Hereinafter, although the form for implementing this invention is demonstrated in detail, this invention is not limited to these.
1. 1. First embodiment: Transparent electrode having a laminate having a two-layer structure 2. Second embodiment: Transparent electrode having a laminate provided with an organic layer 3. Third embodiment: transparent electrode having a laminate provided with a scattering layer Fourth Embodiment: Organic EL Element (Bottom Emission Type)

<< 1. First Embodiment: Transparent Electrode Having a Stack of Two-Layer Structure >>
FIG. 1 is a schematic cross-sectional view showing the configuration of the transparent electrode according to the first embodiment. As shown in this figure, the transparent electrode 10 has a configuration in which a laminated body 10 ′ having a two-layer structure in which a compound layer 1 a and a metal layer 2 are laminated in this order on one main surface side of a transparent substrate 11. Among these, the metal layer 2 which comprises the electrode part in the transparent electrode 10 is a layer comprised with the alloy which has silver or silver as a main component.

  Below, the detail of each component which comprises the transparent electrode 10 of such a laminated structure is demonstrated in order of the transparent substrate 11, the compound layer 1a, and the metal layer 2. FIG. In addition, the transparency of the transparent electrode 10 of the present invention means that the light transmittance at a wavelength of 550 nm is 50% or more.

<Transparent substrate 11>
The transparent substrate 11 is composed of a light-transmitting substrate material, and examples thereof include glass, quartz, and a transparent resin film, but are not limited thereto. Further, the particularly preferable transparent substrate 11 is a resin film capable of giving the transparent electrode 10 flexibility.

  Examples of the glass include silica glass, soda-lime silica glass, lead glass, borosilicate glass, and alkali-free glass. From the viewpoint of adhesion to the compound layer 1a, durability, and smoothness, the surface of these glass materials is subjected to physical treatment such as polishing, or a coating made of an inorganic or organic material, if necessary, A hybrid film is formed by combining these films.

  Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate (TAC), cellulose acetate butyrate, cellulose acetate propionate ( CAP), cellulose esters such as cellulose acetate phthalate, cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide , Polyethersulfone (PES), polyphenylene sulfide, polysulfones Cycloolefin resins such as polyetherimide, polyetherketoneimide, polyamide, fluororesin, nylon, polymethylmethacrylate, acrylic and polyarylates, Arton (trade name, manufactured by JSR) or Appel (trade name, manufactured by Mitsui Chemicals) Etc. can be used.

On the surface of the resin film, a barrier film made of an inorganic film, an organic film, or a hybrid film of both may be formed. The barrier film had a water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) of 0.01 g / (m ² · 24 h) measured by a method according to JIS K 7129-1992. The following barrier films are preferred. Furthermore, the oxygen permeability measured by a method in accordance with JIS K 7126-1987 is 10 ⁻³ ml / (m ² · 24 h · atm) or less, and the water vapor permeability is 10 ⁻⁵ g / (m ² · 24h) The following high-barrier film is preferable.

  As a material for forming the barrier film as described above, any material may be used as long as it has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used. Furthermore, in order to improve the fragility of the barrier film, it is more preferable to have a laminated structure of these inorganic layers and layers (organic layers) made of an organic material. Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times.

  The method for forming the barrier film is not particularly limited. For example, the vacuum deposition method, the sputtering method, the reactive sputtering method, the molecular beam epitaxy method, the cluster ion beam method, the ion plating method, the plasma polymerization method, the atmospheric pressure plasma weighting. A combination method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used, but an atmospheric pressure plasma polymerization method described in JP-A-2004-68143 is particularly preferable.

<Compound layer 1a>
The compound layer 1 a is a layer that is sandwiched between the transparent substrate 11 and the metal layer 2. In this example, the compound layer 1a is a layer configured to contain an alkali metal or an alkaline earth metal and oxygen.

  In film formation of the metal layer 2 composed of silver or an alloy containing silver as a main component, a certain size lump (Ag) atoms adhering to the film formation surface on the transparent substrate 11 are diffused on the surface. Nuclei). Then, the initial thin film growth proceeds along the periphery of this lump (nucleus). For this reason, in the film | membrane of the formation initial stage, there exists a clearance gap between masses and it does not conduct | electrically_connect. If a lump further grows from this state and the thickness is about 15 nm, a part of the lump is connected and barely conducted. However, the film surface is not yet smooth and plasmon absorption is likely to occur. In addition, when applied to an organic EL element, a reduction in rectification ratio or leakage due to the smoothness of the transparent electrode is likely to occur.

  On the other hand, when the compound layer 1a is previously formed on the transparent substrate 11, silver atoms attached to the film formation surface on the compound layer 1a are combined with oxygen atoms in the compound layer 1a, and silver oxide lump (growth nucleus) is formed. Form. The silver oxide (growth nucleus) and a metal material such as silver constituting the metal layer 2 interact, so that the metal material such as silver hardly moves on the transparent substrate 11 or the compound layer 1a. The initial thin film growth of the metal layer 2 proceeds along the periphery of the (growth nucleus).

  Such a compound layer 1a is made of a material in which a metal material such as silver constituting the metal layer 2 and oxygen atoms are easily bonded.

  The easier the silver atoms and oxygen atoms are bonded, the more silver oxide (growth nuclei) can be formed on the film forming surface on the compound layer 1a. Therefore, the distance between the grown nuclei is such that the silver atoms etc. are directly on the transparent substrate 11. It can be made narrower than the space between the lumps when formed by surface diffusion. As a result, a metal material such as silver adheres starting from the silver oxide (growth nucleus), and when the film is grown, a flat layer tends to be formed even if the thickness is small. That is, it is possible to form the metal layer 2 that is conductive even when the thickness is small, and that hardly absorbs plasmon.

Such materials include materials containing alkali metals or alkaline earth metals and oxygen, especially alkali metal or alkaline earth metal oxides, peroxides, complex oxides, alkali metal salts or alkaline earths. For example, Li ₂ O, Rb ₂ O, Cs ₂ O, Li ₂ O ₂ , Rb ₂ O ₂ , Cs ₂ O ₂ , LiAlO ₂ , LiBO ₂ , KAlO ₂ , NaWO ₄ , K ₂ SiO ₃ , Li ₂ CO ₃ , CaCO ₃ , Na ₂ CO _{3 and the} like. In addition, the compound layer 1a may use only 1 type in these materials, and may use it in combination of 2 types.
Among these, from the viewpoint of improving the uniformity and smoothness of the metal layer 2, a material containing an alkaline earth metal is preferable.

  The compound layer 1a is preferably made of a material having an orientation such that oxygen atoms are arranged on the film forming surface side on the compound layer 1a, that is, at the interface between the compound layer 1a and the metal layer 2.

  Moreover, it is preferable that the average thickness of the compound layer 1a is 3 nm or less. Moreover, a monomolecular layer may be sufficient. The average thickness of the compound layer 1a is adjusted by the formation speed and the formation time.

  If the average thickness of the compound layer 1a is 3 nm or less, the uniformity of the metal layer 2 and the smoothness of the electrode surface can be improved without affecting the thickness of the entire transparent electrode.

  The compound layer 1a may have an average thickness of 1 nm or less.

  In general, thin film growth of a material containing a metal or a metal oxide is “nucleation and growth” type film growth, that is, the formed islands are combined. In particular, when the thickness of the formed film is 1 nm or less, the film does not become a complete continuous film but is formed so that at least a part thereof is in contact. In addition, it has been reported that the film gradually approaches a continuous film at 1 to 1.1 nm, and becomes an almost complete continuous film at 1.1 nm or more (http://hdl.handle.net/11094/ 2289, p.39-44).

Therefore, in the range where the average thickness is 1 nm or less, as described above, the compound layer 1a does not become a complete continuous film, but is formed so that at least a part of the islands are in contact with each other. Thereby, for example, when a layer that interacts with a metal material such as silver constituting the metal layer 2 is formed in the lower layer of the compound layer 1a, the layer and the metal layer 2 in the discontinuous portion of the compound layer 1a. Interaction with can be obtained. That is, the synergistic effect of the layer and the compound layer 1a on the metal layer 2 can further improve the uniformity of the metal layer 2 and further improve the smoothness of the electrode surface.
The layer that interacts with a metal material such as silver constituting the metal layer 2 is an organic material that is composed of a compound containing at least one of a nitrogen atom (N) and a sulfur atom (S) as described later. Layer and the like.

  As a method for forming the compound layer 1a, a vapor deposition method can be used. Alternatively, the compound layer 1a having a sufficient thickness can be formed, and this layer can be formed by dry etching to leave the desired thickness described above.

  As the vapor deposition method, for example, a vacuum vapor deposition method, an electron beam vapor deposition method, an ion plating method, an ion beam vapor deposition method, or the like can be used. The deposition time is appropriately selected according to the compound layer 1a to be formed and the formation speed. The deposition rate is preferably 0.1 to 15 Å / second, more preferably 0.1 to 7 Å / second.

  In the method of forming the compound layer 1a having a sufficient thickness on the transparent substrate 11 and then dry etching the layer to a desired thickness, the method for forming the compound layer 1a is not particularly limited. For example, a vapor deposition method such as a vacuum deposition method, a sputtering method, an ion plating method, a plasma CVD method, or a thermal CVD method, or a wet deposition method such as a plating method can be used.

  The dry etching method for the compound layer 1a is an etching method that involves physical collision of etching gas, ions, radicals, etc., and does not include reactive gas etching that performs etching only by chemical reaction. The etching method is not particularly limited as long as it involves such physical collision, and for example, ion beam etching, reverse sputter etching, plasma etching, or the like can be used.

  As described above, when a layer that interacts with a metal material such as silver constituting the metal layer 2 is formed below the compound layer 1a, a desired non-continuous portion is formed on the compound layer 1a after etching. Is preferably formed. In this case, it is preferable to form by ion beam etching.

If the compound layer 1a is too thick, it is difficult to obtain a thin and smooth metal layer 2, and the metal layer 2 formed starting from silver oxide (growth nuclei) formed on the compound layer 1a becomes thick. The average thickness of the compound layer 1a is determined from the difference between the thickness of the compound layer 1a and the etching thickness of the compound layer 1a. The etching thickness of the compound layer 1a is the product of the etching rate and the etching time. The etching rate is obtained from the time until the compound layer 1a having a thickness of 50 nm separately prepared on the glass substrate is etched under the same conditions in advance and the light transmittance after the etching becomes equivalent to that of the glass substrate (approximately 0 nm in thickness). .
Therefore, the average thickness of the compound layer 1a can be adjusted by the dry etching time.

  Note that the silver oxide (growth nuclei) formed on the film formation surface on the compound layer 1a has a so-called island-like structure in which the silver oxides (growth nuclei) are adhered in the form of lumps (growth nuclei) that are separated from each other. It may be formed so that at least a part of islands may contact each other. The shape of the silver oxide (growth nucleus) can be appropriately adjusted according to the purpose, for example, by selecting the material of the compound layer 1a or adjusting the film thickness.

<Metal layer 2>
The metal layer 2 is a layer made of silver or an alloy containing silver as a main component, and is made of silver or an alloy containing silver as a main component, and is a layer formed adjacent to the compound layer 1a. It is.

  The alloy mainly composed of silver (Ag) constituting the metal layer 2 is preferably an alloy containing 50% by mass or more of silver. As an example, an alloy mainly composed of silver (Ag) constituting the metal layer 2 is silver magnesium (AgMg), silver copper (AgCu), silver palladium (AgPd), silver palladium copper (AgPdCu), silver indium (AgIn). , Silver aluminum (AgAl), silver molybdenum (AgMo), and the like.

The metal layer 2 as described above may have a configuration in which silver or an alloy layer mainly composed of silver is divided into a plurality of layers as necessary.

  Further, the metal layer 2 preferably has a thickness in the range of 4 to 12 nm. The film thickness of 12 nm or less is preferable because the absorption component or reflection component of the layer can be kept low and the light transmittance of the metal layer 2 can be maintained. Moreover, the electroconductivity of a layer is also ensured because a film thickness is 4 nm or more.

[Method of forming metal layer 2]
As a method for forming the metal layer 2 as described above, a method using a wet process such as a coating method, an ink jet method, a coating method, a dip method, a vapor deposition method (resistance heating, EB method, etc.), a sputtering method, or a CVD method is used. And a method using a dry process such as

  For example, in the case of forming the metal layer 2 to which the sputtering method is applied, a sputter target of an alloy containing silver as a main component is prepared, and the sputter film formation is performed using the sputter gate. In all cases of the above-mentioned alloys, the metal layer 2 is formed by applying a sputtering method. In particular, silver copper (AgCu), silver palladium (AgPd), silver palladium copper (AgPdCu), or silver molybdenum ( In the case of depositing (AgMo), the metal layer 2 is applied by sputtering.

  In particular, in the case where silver aluminum (AgAl), silver magnesium (AgMg), or silver indium (AgIn) is formed, the metal layer 2 to which the vapor deposition method is applied is also formed. In the case of a vapor deposition method, an alloy component and silver (Ag) are co-deposited. Under the present circumstances, the vapor deposition film which adjusted the addition density | concentration of the alloy component with respect to silver (Ag) which is a main material by adjusting the vapor deposition rate of an alloy component and the vapor deposition rate of silver (Ag), respectively is performed.

  In addition, the metal layer 2 is formed on the compound layer 1a, so that the metal layer 2 is sufficiently conductive even if there is no high-temperature annealing after the film formation. It may be subjected to a high temperature annealing treatment or the like later.

  Further, the transparent electrode 10 as described above may be covered with a protective film or may be laminated with another conductive layer in a state where the laminated body 10 ′ is sandwiched between the transparent substrate 11. In this case, it is preferable that the protective film has light transmittance so as not to impair the light transmittance of the transparent electrode 10.

<Effect of transparent electrode 10>
The transparent electrode 10 configured as described above has a metal layer 2 formed of silver or an alloy containing silver as a main component on a compound layer 1a including an alkali metal or alkaline earth metal and oxygen. Is provided. As a result, silver oxide is formed between the compound layer 1a and the metal layer 2, and the silver oxide and the silver constituting the metal layer 2 or an alloy containing silver as a main component interact to thereby smooth the surface. The metal layer 2 having high surface smoothness can be formed with a uniform thickness even though it is thin.

  As a result of the above, the transparent electrode 10 can achieve both sufficient conductivity and light transmittance by improving the smoothness of the electrode surface.

  Such a transparent electrode 10 is low in cost because it does not use indium (In), which is a rare metal, and has excellent long-term reliability because it does not use a chemically unstable material such as ZnO. It will be.

≪2. Second Embodiment: Transparent Electrode Having Laminate with Organic Layer >>
FIG. 2 is a schematic cross-sectional view showing the configuration of the transparent electrode 20 according to the second embodiment of the present invention. The transparent electrode 20 shown in this figure is different from the transparent electrode 10 described with reference to FIG. 1 above, in which an organic layer 1b is further provided between the transparent substrate 11 and the compound layer 1a, and the laminate has a three-layer structure. The other configuration is the same as the transparent electrode 20 having 20 ′. For this reason, the same code | symbol is attached | subjected to the same component and the overlapping description is abbreviate | omitted.

  That is, the laminated body 20 ′ in the transparent electrode 20 is provided with the organic layer 1 b, the compound layer 1 a, and the metal layer 2 in this order on the transparent substrate 11. In addition, the film thickness of the compound layer 1a in this embodiment shall be a film thickness with which the interaction of the organic layer 1b and the metal layer 2 is obtained. Below, the organic layer 1b which comprises the transparent electrode 20 of such a laminated structure is demonstrated.

<Organic layer 1b>
The organic layer 1 b is a layer provided between the transparent substrate 11 and the compound layer 1 a and is provided on one main surface of the transparent substrate 11. Such an organic layer 1b is configured using a compound containing a nitrogen atom (N) or a sulfur atom (S). In particular, the organic layer 1b is preferably a layer that includes a Lewis base and is composed of a compound having a Lewis base, that is, a compound including an atom having an unshared electron pair. Examples of such a compound having a Lewis base include nitrogen-containing compounds and sulfur-containing compounds.

  As an example, the organic layer 1b is a layer configured using at least one or both of a nitrogen-containing compound and a sulfur-containing compound, and each may contain a plurality of types of compounds. Moreover, the compound which comprises the organic layer 1b may be a compound containing both nitrogen and sulfur.

  The nitrogen-containing compound constituting the organic layer 1b may be a compound containing a nitrogen atom (N), but is particularly preferably an organic compound containing a nitrogen atom having an unshared electron pair. The sulfur-containing compound constituting the organic layer 1b may be a compound containing sulfur (S), but is particularly preferably an organic compound containing a sulfur atom having an unshared electron pair.

  Further, when the nitrogen-containing compound and the sulfur-containing compound constituting the organic layer 1b contain a nitrogen atom or sulfur atom having an unshared electron pair that is stably bonded to silver, which is the main material constituting the metal layer 2 in particular. When the unshared electron pair of the nitrogen atom or sulfur atom is [effective unshared electron pair], it is preferable that the content of the [effective unshared electron pair] is within a predetermined range.

  Here, the “effective unshared electron pair” refers to an unshared electron pair that is not involved in aromaticity and is not coordinated to a metal among the unshared electron pairs of the nitrogen atom or sulfur atom contained in the compound. Suppose that The aromaticity here refers to an unsaturated cyclic structure in which atoms having π electrons are arranged in a ring, and is aromatic according to the so-called “Hückel's rule”. The condition is that the number is “4n + 2” (n = 0 or a natural number).

  [Effective unshared electron pair] is a nitrogen atom or sulfur atom regardless of whether or not the nitrogen atom or sulfur atom itself provided with the unshared electron pair is a hetero atom constituting an aromatic ring. It is selected depending on whether or not the unshared electron pair possessed by is involved in aromaticity. For example, even if a nitrogen atom is a heteroatom constituting an aromatic ring, if the nitrogen atom has an unshared electron pair that does not participate in aromaticity, the unshared electron pair is [effective unshared electron. It is counted as one of the pair. In contrast, even if a nitrogen atom is not a heteroatom that constitutes an aromatic ring, if all of the non-shared electron pairs of the nitrogen atom are involved in aromaticity, the nitrogen atom is not shared. An electron pair is not counted as a [valid unshared electron pair]. The same applies to sulfur atoms. In each compound, the number n of [effective unshared electron pairs] described above matches the number of nitrogen atoms and sulfur atoms having [effective unshared electron pairs].

Particularly in the present embodiment, the number n of [effective unshared electron pairs] with respect to the molecular weight M of such a compound is defined as, for example, the effective unshared electron pair content [n / M]. The organic layer 1b is characterized in that it is composed of a compound selected such that [n / M] is 2.0 × 10 ⁻³ ≦ [n / M]. The organic layer 1b is more preferable if the effective unshared electron pair content [n / M] defined as described above is in the range of 3.9 × 10 ⁻³ ≦ [n / M].

  Moreover, the organic layer 1b should just be comprised using the nitrogen-containing compound or sulfur containing compound whose effective unshared electron pair content [n / M] is the predetermined range mentioned above, and is comprised only with such a compound. Alternatively, such a compound and another compound may be mixed and used. The other compound may or may not contain a nitrogen atom or a sulfur atom, and the effective unshared electron pair content [n / M] may not be within the predetermined range described above.

  When the organic layer 1b is constituted by using a plurality of compounds, for example, based on the mixing ratio of the compounds, the molecular weight M of the mixed compound obtained by mixing these compounds is obtained, and [effective non-sharing with respect to the molecular weight M is obtained. The total number n of [electron pairs] is obtained as an average value of the effective unshared electron pair content [n / M], and this value is preferably within the predetermined range described above. That is, it is preferable that the effective unshared electron pair content [n / M] of the organic layer 1b itself is in a predetermined range.

  In addition, if the organic layer 1b is comprised using a some compound, Comprising: If the mixing ratio (content ratio) of a compound differs in a film thickness direction, the organic of the side by which the metal layer 2 is provided will be provided. The effective unshared electron pair content [n / M] on the surface of the layer 1b may be within a predetermined range.

  Next, the details of the compound constituting the organic layer 1b and the film forming method thereof are the nitrogen-containing compound (1), the nitrogen-containing compound (2), the nitrogen-containing compound (3), the sulfur-containing compound (1), and the sulfur-containing compound. (2) and the method for forming the organic layer 1b will be described in this order.

[Nitrogen-containing compound (1)]
The nitrogen-containing compound constituting the organic layer 1b may be a compound containing a nitrogen atom (N). In particular, it is an organic compound containing a nitrogen atom having an unshared electron pair, and is preferably the following compound.

Specific examples of nitrogen-containing compounds satisfying the above-mentioned effective unshared electron pair content [n / M] of 2.0 × 10 ⁻³ ≦ [n / M] as nitrogen-containing compounds constituting the organic layer 1b are shown below. (No. 1 to No. 45). Each of the nitrogen-containing compounds No. 1 to No. 45 is marked with a circle with respect to the nitrogen atom having [effective unshared electron pair]. Table 1 below shows the molecular weight M of these nitrogen-containing compounds No. 1 to No. 45, the number n of [effective unshared electron pairs], and the effective unshared electron pair content [n / M]. . In the copper phthalocyanine of the following nitrogen-containing compound No. 33, unshared electron pairs that are not coordinated to copper among the unshared electron pairs of the nitrogen atom are counted as [effective unshared electron pairs].

  Table 1 shows the corresponding general formulas when these exemplified nitrogen-containing compounds also belong to the general formulas (1) to (8a) which are nitrogen-containing compounds (2) described below.

[Nitrogen-containing compound (2)]
As the other nitrogen-containing compound (2) constituting the organic layer 1b, in addition to the nitrogen-containing compound (1) whose effective unshared electron pair content [n / M] is within the predetermined range described above, From the viewpoint of film formability, a nitrogen-containing compound (2) represented by the following general formulas (1) to (8a) is used.

  Among the nitrogen-containing compounds represented by these general formulas (1) to (8a) and others, nitrogen-containing compounds that fall within the range of the effective unshared electron pair content [n / M] described above are also included. Any nitrogen-containing compound can be used as the nitrogen-containing compound constituting the organic layer 1b alone (see Table 1 above). On the other hand, if the compound represented by the following general formulas (1) to (8a) is a nitrogen-containing compound that does not fall within the above-mentioned range of the effective unshared electron pair content [n / M], it contains an effective unshared electron pair. The ratio [n / M] is preferably used as a nitrogen-containing compound constituting the organic layer 1b by mixing with a nitrogen-containing compound in the range described above.

  X11 in the general formula (1) represents -N (R11)-or -O-. E101 to E108 in the general formula (1) each represent -C (R12) = or -N =. At least one of E101 to E108 is -N =. R11 and R12 each represent a hydrogen atom (H) or a substituent.

  Examples of this substituent include alkyl groups (for example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group). Etc.), cycloalkyl groups (for example, cyclopentyl group, cyclohexyl group, etc.), alkenyl groups (for example, vinyl group, allyl group, etc.), alkynyl groups (for example, ethynyl group, propargyl group, etc.), aromatic hydrocarbon groups (aromatic For example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group , Pyrenyl group, biphenylyl group), aromatic heterocyclic group (for example, Furyl group, thienyl group, pyridyl group, pyridazinyl group, pyrimidinyl group, pyrazinyl group, triazinyl group, imidazolyl group, pyrazolyl group, thiazolyl group, quinazolinyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group Any carbon atom constituting the carboline ring is substituted with a nitrogen atom), phthalazinyl group, etc.), heterocyclic group (eg, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group ( For example, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group ( For example, Nonoxy group, naphthyloxy group, etc.), alkylthio group (eg, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group) Etc.), arylthio groups (eg, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl groups (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryl Oxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (eg, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group) Group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (for example, Acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (For example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenyl group Carbonyloxy group, etc.), amide groups (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonyl) Amino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexyl) Aminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl Bonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group naphthylureido) Group, 2-pyridylaminoureido group, etc.), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2 -Pyridylsulfinyl group etc.), alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2 -Ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group or heteroarylsulfonyl group (eg, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (eg, amino group, ethylamino group, Dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino group, 2-pyridylamino group, piperidyl group (also called piperidinyl group), 2,2,6,6 -Tetramethylpiperidinyl group, etc.), halogen atom (eg, fluorine atom, chlorine atom, bromine atom etc.), fluorinated hydrocarbon group (eg, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluoro) Phenyl group, etc.), cyano group Nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.), phosphate ester group (for example, dihexyl phosphoryl group, etc.), phosphorous acid An ester group (for example, diphenylphosphinyl group etc.), a phosphono group, etc. are mentioned.

  Some of these substituents may be further substituted with the above substituents. In addition, a plurality of these substituents may be bonded to each other to form a ring.

  The nitrogen-containing compound represented by the general formula (1a) is one form of the nitrogen-containing compound represented by the general formula (1), and the nitrogen-containing compound in which X11 in the general formula (1) is -N (R11)-. A compound. Moreover, as a more preferable form, in E101-E108 in General formula (1a), one of E101-E104 is -N = and / or one of E105-E108 is -N =.

  The nitrogen-containing compound represented by the general formula (1a-1) is one form of the nitrogen-containing compound represented by the general formula (1a), and the nitrogen-containing compound in which E104 in the general formula (1a) is -N =. It is.

  The nitrogen-containing compound represented by the general formula (1a-2) is another embodiment of the nitrogen-containing compound represented by the general formula (1a), and E103 and E106 in the general formula (1a) are represented by -N = A nitrogen-containing compound.

  The nitrogen-containing compound represented by the general formula (1b) is another embodiment of the nitrogen-containing compound represented by the general formula (1). X11 in the general formula (1) is -O-, and E104 is- Nitrogen-containing compound with N =.

  The general formula (2) is also an embodiment of the general formula (1). In the formula of the general formula (2), Y21 represents a divalent linking group composed of an arylene group, a heteroarylene group, or a combination thereof. E201 to E216 and E221 to E238 each represent -C (R21) = or -N =. R21 represents a hydrogen atom (H) or a substituent. However, at least one of E221 to E229 and at least one of E230 to E238 represents -N =. k21 and k22 represent an integer of 0 to 4, but k21 + k22 is an integer of 2 or more.

  In the general formula (2), examples of the arylene group represented by Y21 include o-phenylene group, p-phenylene group, naphthalenediyl group, anthracenediyl group, naphthacenediyl group, pyrenediyl group, naphthylnaphthalenediyl group, and biphenyldiyl. Groups (for example, [1,1′-biphenyl] -4,4′-diyl group, 3,3′-biphenyldiyl group, 3,6-biphenyldiyl group, etc.), terphenyldiyl group, quaterphenyldiyl group And kinkphenyldiyl group, sexiphenyldiyl group, septiphenyldiyl group, octiphenyldiyl group, nobiphenyldiyl group, deciphenyldiyl group and the like.

  In the general formula (2), examples of the heteroarylene group represented by Y21 include a carbazole ring, a carboline ring, a diazacarbazole ring (also referred to as a monoazacarboline ring, and one of carbon atoms constituting the carboline ring is nitrogen. The ring structure is replaced by an atom), a triazole ring, a pyrrole ring, a pyridine ring, a pyrazine ring, a quinoxaline ring, a thiophene ring, an oxadiazole ring, a dibenzofuran ring, a dibenzothiophene ring, and an indole ring. And the like.

  As a preferred embodiment of the divalent linking group consisting of an arylene group, heteroarylene group or a combination thereof represented by Y21, among the heteroarylene groups, a condensed aromatic heterocyclic ring formed by condensing three or more rings is used. A group derived from a condensed aromatic heterocyclic ring formed by condensing three or more rings is preferably included, and a group derived from a dibenzofuran ring or a dibenzothiophene ring is preferable. Are preferred.

  In the general formula (2), when R21 of —C (R21) ═ represented by E201 to E216 and E221 to E238 is a substituent, examples of the substituent include R11 of the general formula (1), The substituents exemplified as R12 apply similarly.

  In General formula (2), it is preferable that 6 or more of E201 to E208 and 6 or more of E209 to E216 are each represented by -C (R21) =.

  In the general formula (2), it is preferable that at least one of E225 to E229 and at least one of E234 to E238 represent -N =.

  Furthermore, in General formula (2), it is preferable that any one of E225-E229 and any one of E234-E238 represent -N =.

  Moreover, in General formula (2), it is mentioned as a preferable aspect that E221-E224 and E230-E233 are each represented by -C (R21) =.

  Further, in the nitrogen-containing compound represented by the general formula (2), it is preferable that E203 is represented by -C (R21) = and R21 represents a linking site, and E211 is also -C (R21) = It is preferable that R21 represents a linking site.

  Further, E225 and E234 are preferably represented by -N =, and E221 to E224 and E230 to E233 are each preferably represented by -C (R21) =.

  The general formula (3) is also an embodiment of the general formula (1a-2). In the general formula (3), E301 to E312 each represent —C (R31) ═, and R31 represents a hydrogen atom (H) or a substituent. Y31 represents a divalent linking group composed of an arylene group, a heteroarylene group, or a combination thereof.

  In the general formula (3), when R31 in —C (R31) ═ represented by E301 to E312 is a substituent, examples of the substituent are exemplified as R11 and R12 in the general formula (1). The same substituents apply as well.

  Moreover, in General formula (3), as a preferable aspect of the bivalent coupling group which consists of an arylene group represented by Y31, heteroarylene group, or those combinations, the thing similar to Y21 of General formula (2) is mentioned. .

  The general formula (4) is also an embodiment of the general formula (1a-1). In the general formula (4), E401 to E414 each represent -C (R41) =, and R41 represents a hydrogen atom (H) or a substituent. Ar41 represents a substituted or unsubstituted aromatic hydrocarbon ring or aromatic heterocyclic ring. Furthermore, k41 represents an integer of 3 or more.

  In the general formula (4), when R41 in —C (R41) ═ represented by E401 to E414 is a substituent, examples of the substituent are R11 and R12 in the general formula (1). The same substituents apply as well.

  In the general formula (4), when Ar41 represents an aromatic hydrocarbon ring, the aromatic hydrocarbon ring includes benzene ring, biphenyl ring, naphthalene ring, azulene ring, anthracene ring, phenanthrene ring, pyrene ring, chrysene Ring, naphthacene ring, triphenylene ring, o-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen And a ring, a picene ring, a pyrene ring, a pyranthrene ring, and an anthraanthrene ring. These rings may further have the substituents exemplified as R11 and R12 in the general formula (1).

  In the general formula (4), when Ar41 represents an aromatic heterocycle, the aromatic heterocycle includes a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, Triazine ring, benzimidazole ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, phthalazine ring, carbazole ring And azacarbazole ring. The azacarbazole ring refers to one in which at least one carbon atom of the benzene ring constituting the carbazole ring is replaced with a nitrogen atom. These rings may further have the substituents exemplified as R11 and R12 in the general formula (1).

  In the general formula (5), R51 represents a substituent. E501, E502, E511 to E515, E521 to E525 each represent -C (R52) = or -N =. E503 to E505 each represent -C (R52) =. R52 represents a hydrogen atom (H) or a substituent. At least one of E501 and E502 is -N =, at least one of E511-E515 is -N =, and at least one of E521-E525 is -N =.

  In the general formula (5), when R51 represents a substituent and R52 represents a substituent, examples of these substituents are the same as those exemplified as R11 and R12 in the general formula (1). The

  In the general formula (6), E601 to E612 each represent —C (R61) ═ or —N═, and R61 represents a hydrogen atom (H) or a substituent. Ar61 represents a substituted or unsubstituted aromatic hydrocarbon ring or aromatic heterocyclic ring.

  In the general formula (6), when R61 of —C (R61) ═ represented by E601 to E612 is a substituent, examples of the substituent include R11 and R12 of the general formula (1). The same substituents apply as well.

  In the general formula (6), examples of the substituted or unsubstituted aromatic hydrocarbon ring or aromatic heterocycle represented by Ar61 include those similar to Ar41 in the general formula (4).

  In the general formula (7), R71 to R73 each represents a hydrogen atom (H) or a substituent, and Ar71 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group.

  In the general formula (7), when R71 to R73 are each a substituent, examples of the substituent are the same as those exemplified as R11 and R12 in the general formula (1).

  In the general formula (7), the aromatic hydrocarbon ring or aromatic heterocyclic ring represented by Ar71 may be the same as Ar41 in the general formula (4).

  The general formula (8) is also a form of the general formula (7). In the general formula (8), R81 to R86 each represent a hydrogen atom (H) or a substituent. E801 to E803 each represent —C (R87) ═ or —N═, and R87 represents a hydrogen atom (H) or a substituent. Ar81 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group.

  In the general formula (8), when R81 to R87 are each a substituent, examples of the substituent are the same as those exemplified as R11 and R12 in the general formula (1).

  In the general formula (8), the aromatic hydrocarbon ring or aromatic heterocyclic ring represented by Ar81 may be the same as Ar41 in the general formula (4).

  The nitrogen-containing compound represented by the general formula (8a) is one form of the nitrogen-containing compound represented by the general formula (8), and Ar81 in the general formula (8) is a carbazole derivative. In the general formula (8), E804 to E811 each represent —C (R88) ═ or —N═, and R88 represents a hydrogen atom (H) or a substituent. At least one of E808 to E811 is -N =, and E804 to E807 and E808 to E811 may be bonded to each other to form a new ring.

  In the general formula (8a), when R88 is a substituent, the substituents exemplified as R11 and R12 in the general formula (1) are similarly applied as examples of the substituent.

  Further, in the above general formulas (1) to (8a), from the viewpoint of enhancing the uniformity of the metal layer 2 and enhancing the smoothness due to the interaction between the organic layer 1b and the metal layer 2, the general formula (1a), Nitrogen-containing compounds represented by (1a-2), (3), (7), (8) and (8a) are preferred.

[Nitrogen-containing compound (3)]
Further, as other nitrogen-containing compounds (3) constituting the organic layer 1b, in addition to the above general formulas (1) to (8a), nitrogen-containing compounds 1 to 166 shown below as specific examples are exemplified. . These nitrogen-containing compounds are materials having excellent film forming properties. These nitrogen-containing compounds can also be used as materials constituting the electron transport layer or the electron injection layer in the organic EL device. These nitrogen-containing compounds 1 to 166 also include the nitrogen-containing compound (1) that falls within the range of the effective unshared electron pair content [n / M] described above. If present, it can be used alone as a nitrogen-containing compound constituting the organic layer 1b. Further, among these nitrogen-containing compounds 1 to 166, there is also a nitrogen-containing compound (2) that applies to the general formulas (1) to (8a) described above.

[Synthesis example of nitrogen-containing compound]
Although the specific synthesis example of the nitrogen-containing compound 5 is shown as a synthesis example of a typical nitrogen-containing compound below, it is not limited to this.

Step 1: (Synthesis of Intermediate 1)
Under a nitrogen atmosphere, 2,8-dibromodibenzofuran (1.0 mol), carbazole (2.0 mol), copper powder (3.0 mol), potassium carbonate (1.5 mol), DMAc (dimethylacetamide) 300 ml Mixed in and stirred at 130 ° C. for 24 hours. The reaction solution thus obtained was cooled to room temperature, 1 L of toluene was added, washed with distilled water three times, the solvent was distilled off from the washed product under a reduced pressure atmosphere, and the residue was subjected to silica gel flash chromatography (n-heptane: Purification was performed using toluene = 4: 1 to 3: 1), and Intermediate 1 was obtained with a yield of 85%.

Step 2: (Synthesis of Intermediate 2)
Intermediate 1 (0.5 mol) was dissolved in 100 ml of DMF (dimethylformamide) at room temperature under air, NBS (N-bromosuccinimide) (2.0 mol) was added, and the mixture was stirred overnight at room temperature. The resulting precipitate was filtered and washed with methanol, yielding intermediate 2 in 92% yield.

Step 3: (Synthesis of nitrogen-containing compound 5)
Under a nitrogen atmosphere, intermediate 2 (0.25 mol), 2-phenylpyridine (1.0 mol), ruthenium complex [(η ₆ -C ₆ H ₆ ) RuCl ₂ ] ₂ (0.05 mol), triphenyl Phosphine (0.2 mol) and potassium carbonate (12 mol) were mixed in 3 L of NMP (N-methyl-2-pyrrolidone) and stirred at 140 ° C. overnight.

After cooling the reaction solution to room temperature, 5 L of dichloromethane was added, and the reaction solution was filtered. Next, the solvent was distilled off from the filtrate under reduced pressure (800 Pa, 80 ° C.), and the residue was purified by silica gel flash chromatography (CH ₂ Cl ₂ : Et ₃ N = 20: 1 to 10: 1).

  After distilling off the solvent from the purified product under reduced pressure, the residue was dissolved again in dichloromethane and washed three times with water. The substance obtained by washing was dried over anhydrous magnesium sulfate, and the solvent was distilled off from the dried substance in a reduced-pressure atmosphere to obtain nitrogen-containing compound 5 in a yield of 68%.

[Sulfur-containing compound (1)]
The sulfur-containing compound (1) constituting the organic layer 1b may be a compound containing sulfur (S), but is particularly an organic compound containing a sulfur atom having an unshared electron pair, and a divalent sulfur atom. It is represented by the following general formula (9), general formula (10), general formula (11), or general formula (12).

  In the general formula (9), R91 and R92 each represent a substituent.

  As the substituents represented by R91 and R92, the substituents exemplified as R11 and R12 in the general formula (1) are similarly applied.

  In the general formula (10), R93 and R94 represent a substituent.

  Examples of the substituent represented by R93 and R94 include the same substituents as R91 and R92.

  In the general formula (11), R95 represents a substituent.

  Examples of the substituent represented by R95 include the same substituents as R91 and R92.

  In the general formula (12), R96 represents a substituent.

  Examples of the substituent represented by R96 include the same substituents as R91 and R92.

  Below, the specific example of the organic compound (sulfur containing compound) containing the sulfur atom applicable to the organic layer 1b which concerns on this invention is given.

  Specific examples of the sulfur-containing compound represented by the general formula (9) include the following 1-1 to 1-9.

  Specific examples of the sulfur-containing compound represented by the general formula (10) include the following 2-1 to 2-11.

  Moreover, the following 3-1 to 3-23 are mentioned as a specific example of the sulfur containing compound represented by General formula (11).

  Moreover, the following 4-1 is mentioned as a specific example of the sulfur containing compound represented by General formula (12).

[Sulfur-containing compound (2)]
As other sulfur-containing compounds (2) constituting the organic layer 1b, in addition to the general formulas (9) to (12) as described above, polymers having a sulfur atom shown below as specific examples (hereinafter referred to as S polymer). Are abbreviated) 5-1 to 5-12.

  Here, the organic layer 1b is configured to contain 50% by mass or more of this S polymer. Moreover, Preferably it is 70 mass% or more. S polymer may be one kind or a plurality may be mixed. Moreover, the organic layer 1b may mix the compound which does not have a sulfur atom other than S polymer in the range which does not inhibit the effect of this invention.

  The S polymer having a weight average molecular weight of 1,000 to 1,000,000 is used. Further, it is sufficient that the polymer repeating unit has a sulfide bond, a disulfide bond, a mercapto group, a sulfone group, a thiocarbonyl bond and the like, and a sulfide bond and a mercapto group are particularly preferable.

  Examples of the polymerization form of the S polymer include a polycondensation polymer such as polyester, an acrylic derivative monomer, and a vinyl polymerization polymer composed of a styrene derivative monomer, and any of them can be preferably used.

  In addition, the subscript of each monomer unit shows weight%. n represents 100% by weight.

The weight average molecular weight of the S polymer of the present invention is a value measured under the following measurement conditions at room temperature.
(Measurement condition)
Equipment: Tosoh High Speed GPC Equipment HLC-8220GPC
Column: TOSOH TSKgel Super HM-M
Detector: RI and UV
Eluent flow rate: 0.6 ml / min Temperature: 30 ° C
Sample concentration: 0.1% by mass
Sample volume: 100 μl
Calibration curve: prepared with standard polystyrene: standard polystyrene STK standard polystyrene (manufactured by Tosoh Corporation) Mw = 100000 to 500-500 calibration curves (also referred to as calibration curves) were used to calculate the molecular weight. . Here, 13 samples were set at approximately equal intervals.

[Method of forming organic layer 1b]
As a method for forming the organic layer 1b as described above, a wet process such as a coating method, an inkjet method, a coating method, a dip method, a vapor deposition method (resistance heating method, EB method, etc.), a sputtering method, a CVD method, or the like. And a method using a dry process such as a method. Of these, the vapor deposition method is preferably applied.

  In particular, in the case where the organic layer 1b is formed using a plurality of compounds, co-evaporation in which a plurality of compounds are simultaneously supplied from a plurality of evaporation sources is applied. If a polymer material is used as the compound, a coating method is preferably applied. In this case, a coating solution in which the compound is dissolved in a solvent is used. The solvent in which the compound is dissolved is not limited. Furthermore, if the organic layer 1b is formed using a plurality of compounds, the coating solution may be prepared using a solvent that can dissolve the plurality of compounds.

<Effect of transparent electrode 20>
Such a transparent electrode 20 has a configuration in which an organic layer 1b is provided between the transparent substrate 11 and the compound layer 1a, and the compound layer 1a has a film thickness that allows interaction between the organic layer 1b and the metal layer 2 to be obtained. It is said. As a result, the metal layer 2 made of silver or an alloy containing silver as a main component is reduced in the diffusion distance of silver at the adjacent interface due to the interaction with the organic layer 1b, thereby suppressing aggregation. . Therefore, in general, a silver thin film that is easily isolated in an island shape by film growth of a nuclear growth type (Volume-Weber: VW type) is a single-layer growth type (Frank-van der Merwe: FM type). As a result, a film is formed.

  Therefore, in addition to the effect of the transparent electrode 10 of the first embodiment, an interaction between the organic layer 1b and the metal layer 2 is obtained, that is, synergistic with respect to the metal layer 2 of the organic layer 1b and the compound layer 1a. Effects can be obtained. Furthermore, the organic layer 1b can smooth the uneven surface of the layer formed in the lower layer. Thereby, the transparent electrode 20 can achieve both sufficient electrical conductivity and light transmittance by further improving the smoothness of the electrode surface.

≪3. Third Embodiment: Transparent Electrode Having Laminate with Scattering Layer >>
FIG. 3 is a schematic cross-sectional view showing the configuration of the transparent electrode 30 according to the third embodiment of the present invention. The transparent electrode 30 shown in this figure is different from the transparent electrode 20 described with reference to FIG. 2 above, in which a scattering layer 1c is further provided between the transparent substrate 11 and the organic layer 1b, and a laminate having a four-layer structure. The other configuration is the same as the transparent electrode 30 having 30 ′. For this reason, the same code | symbol is attached | subjected to the same component and the overlapping description is abbreviate | omitted.
In the case where the transparent substrate 11 whose surface is covered with a barrier film or the like is used, these are collectively referred to as the transparent substrate 11.

  That is, the multilayer body 30 ′ in the transparent electrode 30 is provided with the scattering layer 1 c, the organic layer 1 b, the compound layer 1 a, and the metal layer 2 in this order on the transparent substrate 11. In addition, the film thickness of the compound layer 1a in this embodiment shall be a film thickness with which the interaction of the organic layer 1b and the metal layer 2 is obtained. Below, the scattering layer 1c which comprises the transparent electrode 30 of such a laminated structure is demonstrated.

<Scattering layer 1c>
The scattering layer 1 c is a layer provided between the transparent substrate 11 and the organic layer 1 b, and is provided adjacent to one main surface of the transparent substrate 11. The scattering layer 1c is a layer that improves the light extraction efficiency of the emitted light h, and the transmittance for visible light is preferably 50% or more, more preferably 55% or more, and 60% or more. It is particularly preferred.

  Moreover, it is preferable that the scattering layer 1c is a high refractive index layer whose refractive index in wavelength 550nm exists in the range of 1.7-2.5. By setting the refractive index to 1.7 or more, waveguide mode light confined in the light emitting layer of the organic EL element and plasmon mode light reflected from the cathode can extract light of a specific optical mode. On the other hand, even in the higher-order mode of the plasmon mode, there is almost no light in a region with a refractive index of 2.5 or higher, and the amount of light that can be extracted even with a refractive index higher than this does not increase. The rate may be less than 2.5.

  Such a scattering layer 1c may form a film with a single material having a refractive index of 1.7 or more and less than 2.5, or a mixture of two or more materials to have a refractive index of 1.7 or more and 2. A film of less than 5 may be formed. In the case of such a mixed system, the refractive index of the scattering layer 1c can be substituted by a calculated refractive index calculated by a total value obtained by multiplying the refractive index specific to each material by the mixing ratio. In this case, the refractive index of each material may be less than 1.7 or 2.5 or more, and the mixed film may have a refractive index of 1.7 or more and less than 2.5. That's fine.

  Further, the scattering layer 1c of the present invention may be a mixed scattering layer using a difference in refractive index due to a mixture of resin and particles, or a shape control scattering layer formed by shape control of a concavo-convex structure or the like. Hereinafter, the scattering layer 1c will be described in detail in the order of (1.1) mixed scattering layer and (1.2) shape control scattering layer.

[1.1 Mixed scattering layer (scattering layer 1c)]
The case where the scattering layer 1c of the present invention is a layer that diffracts or diffuses light (mixed scattering layer) will be described.

  The mixed scattering layer of the present invention is a layer provided between the transparent substrate 11 and the organic layer 1b, and is particularly preferably provided adjacent to the transparent substrate 11. The mixed scattering layer is composed of a layer medium and particles contained in the layer medium. The refractive index difference between the resin material (binder) which is a layer medium and the contained particles is larger in the refractive index of the particles, being 0.03 or more, preferably 0.1 or more, more preferably 0. .2 or more, particularly preferably 0.3 or more. When the difference in refractive index between the layer medium and the particles is 0.03 or more, a scattering effect occurs at the interface between the layer medium and the particles. A larger refractive index difference is preferable because refraction at the interface increases and the scattering effect improves.

  As described above, the mixed scattering layer is a layer that diffuses light by the difference in refractive index between the layer medium and the particles. Therefore, the contained particles are preferably transparent particles having a particle size equal to or larger than a region that causes Mie scattering in the visible light region, and the average particle size is preferably 0.2 μm or more.

On the other hand, when the particle size is larger, it is necessary to flatten the roughness of the mixed scattering layer containing particles, which is disadvantageous in terms of process load and film absorption. For this reason, the upper limit of the average particle diameter is preferably less than 10 μm, more preferably less than 5 μm, particularly preferably less than 3 μm, and most preferably less than 1 μm.
Here, the average particle diameter of the high refractive index particles can be measured, for example, by an apparatus using a dynamic light scattering method such as Nanotrack UPA-EX150 manufactured by Nikkiso Co., Ltd., or by image processing of an electron micrograph.

  Such particles are not particularly limited and can be appropriately selected according to the purpose. The particles may be organic fine particles or inorganic fine particles, and among them, inorganic fine particles having a high refractive index. Is preferred.

  Examples of organic fine particles having a high refractive index include polymethyl methacrylate beads, acrylic-styrene copolymer beads, melamine beads, polycarbonate beads, styrene beads, crosslinked polystyrene beads, polyvinyl chloride beads, benzoguanamine-melamine formaldehyde beads, and the like. Can be mentioned.

Examples of the inorganic fine particles having a high refractive index include inorganic oxide particles composed of at least one oxide selected from zirconium, titanium, aluminum, indium, zinc, tin, antimony, and the like. Specific examples of the inorganic oxide particles include ZrO ₂ , TiO ₂ , BaTiO ₃ , Al ₂ O ₃ , In ₂ O ₃ , ZnO, SnO ₂ , Sb ₂ O ₃ , ITO, SiO ₂ , ZrSiO ₄ , zeolite. Among them, TiO ₂ , BaTiO ₃ , ZrO ₂ , ZnO and SnO ₂ are preferable, and TiO ₂ is most preferable. Of TiO _2, the rutile type is more preferable than the anatase type because the catalyst activity is low, so that the weather resistance of the high refractive index layer and the adjacent layer is high and the refractive index is high.

  In addition, these particles are used in the form of a surface treatment from the viewpoint of improving dispersibility and stability when used as a dispersion liquid in order to be contained in a mixed scattering layer having a high refractive index. It is possible to select whether to use the one not applied.

  In addition, as the high refractive index material constituting the scattering layer 1c, quantum dots described in International Publication No. 2009/014707 and US Pat. No. 6,608,439 can be suitably used.

The high refractive index particles have a refractive index of 1.7 or more, preferably 1.85 or more, and particularly preferably 2.0 or more. If the refractive index is less than 1.7, the difference in refractive index from the binder becomes small, the amount of scattering decreases, and the effect of improving the light extraction efficiency may not be obtained.
On the other hand, the upper limit of the refractive index of the high refractive index particles is less than 3.0. Within the above range, if the refractive index difference with the binder is large, a sufficient amount of scattering can be obtained, and the effect of improving the light extraction efficiency can be obtained.

As a method for forming the mixed scattering layer, for example, when the layer medium is a resin material, the above-mentioned particles are dispersed in a resin material (polymer) solution (a solvent in which particles are not dissolved) used as a medium, and transparent. It is formed by applying on the substrate 11.
Since these particles are actually polydisperse particles and difficult to arrange regularly, they have a diffractive effect locally, but many parts change the direction of light by diffusion. Improve extraction efficiency.

  As the binder of the present invention, known resins (binders) can be used without particular limitation. For example, acrylic acid esters, methacrylic acid esters, polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate (PEN), polycarbonate (PC), polyarylate, polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), polystyrene (PS), nylon (Ny), aromatic polyamide, polyether ether ketone, polysulfone, polyether sulfone, polyimide , A resin film such as polyetherimide, a heat-resistant transparent film (product name: Sila-DEC, manufactured by Chisso Corporation) with a silsesquioxane having an organic-inorganic hybrid structure, perfluoroalkyl In addition to a group-containing silane compound (for example, (heptadecafluoro-1,1,2,2-tetradecyl) triethoxysilane), a fluorine-containing copolymer comprising a fluorine-containing monomer and a monomer for imparting a crosslinkable group as constituent units Examples include coalescence. These resins can be used in combination of two or more. Among these, those having an organic-inorganic hybrid structure are preferable.

The following hydrophilic resins can also be used. Examples of hydrophilic resins include water-soluble resins, water-dispersible resins, colloid-dispersed resins, and mixtures thereof. Examples of the hydrophilic resin include acrylic resins, polyester resins, polyamide resins, polyurethane resins, fluorine resins, and the like. For example, polyvinyl alcohol, gelatin, polyethylene oxide, polyvinyl pyrrolidone, casein, starch, agar, carrageenan, polyacrylic resin. Polymers such as acid, polymethacrylic acid, polyacrylamide, polymethacrylamide, polystyrene sulfonic acid, cellulose, hydroxyl ethyl cellulose, carboxyl methyl cellulose, hydroxyl ethyl cellulose, dextran, dextrin, pullulan, water-soluble polyvinyl butyral can be mentioned, but these Among these, polyvinyl alcohol is preferable.
As the polymer used as the binder resin, one type may be used alone, or two or more types may be mixed and used as necessary.

  Similarly, conventionally known resin particles (emulsions) and the like can also be suitably used.

  Further, as the binder, a resin curable mainly by ultraviolet rays / electron beams, that is, a mixture of an ionizing radiation curable resin and a thermoplastic resin and a solvent, or a thermosetting resin can be suitably used.

In the present invention, a compound capable of forming a metal oxide, metal nitride or metal oxynitride by ultraviolet irradiation under a specific atmosphere is particularly preferably used. As the compound suitable for the present invention, a compound which can be modified at a relatively low temperature described in JP-A-8-112879 is preferable.
Specifically, polysiloxane (including polysilsesquioxane) having Si—O—Si bond, polysilazane having Si—N—Si bond, both Si—O—Si bond and Si—N—Si bond And polysiloxazan containing These can be used in combination of two or more. Moreover, it can be used even if different compounds are sequentially laminated or simultaneously laminated.

  Here, the polysilazane preferably used in the present invention is represented by the following general formula (I).

In general formula (I), R ₁ , R ₂ and R ₃ each represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an alkylsilyl group, an alkylamino group or an alkoxy group.

In the present invention, perhydropolysilazane in which all of R ₁ , R ₂ and R ₃ are hydrogen atoms is particularly preferred from the viewpoint of compactness.

  As a curing method of the ionizing radiation curable resin composition as the binder, the ionizing radiation curable resin composition can be cured by a normal curing method, that is, irradiation with an electron beam or ultraviolet rays.

[1.2 Shape Control Scattering Layer (Scattering Layer 1c)]
Next, the case where the scattering layer 1c of the present invention is a layer that diffracts or diffuses light (shape control scattering layer) will be described.

The shape control scattering layer of the present invention is configured to have an uneven structure that diffracts or diffuses light, and is provided adjacent to the transparent substrate 11. Thereby, for example, when the metal layer 2 is provided above the shape control scattering layer to produce a transparent electrode, total reflection at the interface between the transparent substrate 11 and the metal layer 2 can be prevented. The amount of light extracted from the transparent substrate (light extraction surface) side of the transparent electrode can be increased as compared with the transparent electrode not provided with the electrode. That is, the light transmittance of the transparent electrode can be improved.
Further, the configuration of the transparent electrode is not limited to this, and the same effect can be obtained even in the case where the organic layer 1b and the compound layer 1a described above are sandwiched between the transparent substrate 11 and the metal layer 2, for example. Have.

Although the concavo-convex structure for diffracting light is not shown, it is formed of a concavo-convex structure having a constant pitch (period).
In order to improve the extraction efficiency of visible light, it is necessary to be a diffraction grating for diffracting light within a wavelength range of 400 to 750 nm in a visible light medium. There is a fixed relationship between the incident angle and the exit angle of light to the diffraction grating, the diffraction grating interval (period of the concave / convex array), the light wavelength, the refractive index of the medium, the diffraction order, etc., and visible light and its vicinity In the present invention, the pitch of the concave / convex array needs to have a constant value in the range of 150 to 3000 nm corresponding to the wavelength at which the extraction efficiency is improved.

  The concavo-convex structure acting as a diffraction grating is described in, for example, Japanese Patent Application Laid-Open Nos. 11-283951 and 2003-115377. The stripe-shaped diffraction grating does not have a diffraction effect in the direction parallel to the stripe, and thus preferably functions as a diffraction grating uniformly from any direction two-dimensionally. For example, it is preferable that a concave portion and a convex portion having a predetermined shape are regularly formed at a predetermined interval as a shape viewed from the normal direction of the transparent substrate surface or the display surface.

  Examples of the shape of the hole constituting the recess include, but are not particularly limited to, a circle, a triangle, a quadrangle, and a polygon. The inner diameter of the hole (assuming a circle with the same area) is preferably in the range of 75 to 1500 nm.

  Moreover, as a cross-sectional shape seen from the planar direction of a recessed part (dent), hemispherical, rectangular shape, kamaboko shape, pyramid shape etc. are mentioned, However It does not specifically limit. The depth of the recess is preferably in the range of 50 to 1600 nm, and more preferably in the range of 50 to 1200 nm. When the depth of the recess is 50 nm or more, the effect of diffraction or scattering by the shape control scattering layer can be sufficiently obtained. On the other hand, when the depth of the recess is 1600 nm or less, the effect of diffraction or scattering can be sufficiently obtained without impairing the smoothness of the display element.

  In order to obtain a diffraction grating, it is preferable that the arrangement of these concave portions is repeated regularly two-dimensionally, such as a square lattice shape (square lattice shape) or a honeycomb lattice shape.

  In the case of a protrusion (convex type), the shape of the protrusion is the same as the shape of the concave portion. For example, when the convex portion is a columnar protrusion, the shape viewed from the normal direction of the surface is circular or triangular. , Square or polygonal. The height and pitch (cycle) of the protrusions are the same as in the case where the above-described holes are formed. That is, the shape of these unevennesses may be formed so that the convex portion has the value of the concave portion.

  By forming the shape control scattering layer having such a concavo-convex structure on the transparent substrate 11, for example, when light emission is extracted from the transparent substrate 11 side, light having a wavelength corresponding to the pitch (period) of the concavo-convex structure is obtained. The extraction efficiency can be improved.

  On the other hand, the concavo-convex structure for diffusing light is a structure for diffusing light by light diffraction, refraction, or reflection, and has an average pitch (period) in the range of 0.3 to 20 μm and an average height, for example. There is a wave shape or the like in the range of 100 to 7000 nm which is about 1/5 to 1/3 of the pitch. In order to make the amount of light that diffuses and takes out the light propagating inside the light emitting layer by total reflection or reflection by the counter electrode 5 be at least 100 nm or higher in order to make the amount of light sufficient as compared with the amount of light emitted directly to the outside. Preferably there is. In addition, if the pitch (period) of the corrugated shape is too long, light is absorbed by the light emitting layer before the scattering phenomenon occurs, and if the average height becomes too large, it becomes difficult to form the light emitting layer provided on the upper part. Not desirable.

<Effect of transparent electrode 30>
Such a transparent electrode 30 has a configuration in which the scattering layer 1c is provided between the transparent substrate 11 and the organic layer 1b, thereby increasing the amount of light extracted from the transparent substrate 11 (light extraction surface) side. it can. That is, the light transmittance of the transparent electrode 30 toward the transparent substrate 11 can be improved.

  Therefore, in addition to the effect of the transparent electrode 20 of the second embodiment, the light transmittance toward the transparent substrate 11 of the transparent electrode 30 is further improved.

  Furthermore, although this embodiment demonstrated the structure which provides the scattering layer 1c in the transparent electrode 20 of 2nd Embodiment, you may combine with the transparent electrode 10 of 1st Embodiment. In this case, in the transparent electrode 30 shown in FIG. 3, for example, the scattering layer 1c, the compound layer 1a, and the metal layer 2 are provided in this order on the transparent substrate 11.

  As described above, the transparent electrode having a configuration combining the present embodiment and the first embodiment has a scattering layer 1c between the transparent substrate 11 and the compound layer 1a as compared with the transparent electrode 10 of the first embodiment. Therefore, the amount of light extracted from the transparent substrate 11 (light extraction surface) side can be increased. Therefore, in addition to the effects of the first embodiment, the light transmittance of the transparent electrode 30 toward the transparent substrate 11 is further improved.

<Use of transparent electrode>
The transparent electrode described in the first to third embodiments can be used for various electronic devices. Examples of electronic devices include organic electroluminescent elements, LEDs (light emitting diodes), liquid crystal elements, solar cells, touch panels, etc. As electrode members that require light transmission in these electronic devices, A transparent electrode can be used.

  In the following, an embodiment of an organic EL element using a transparent electrode as an anode or a cathode will be described as an example of application.

<< 4. Fourth Embodiment: Organic EL Element (Bottom Emission Type) >>
FIG. 4 is a schematic cross-sectional view showing a configuration of an organic EL element according to the fourth embodiment of the present invention. In this embodiment, the transparent electrode 10 of 1st Embodiment is applied as a transparent electrode, and the structure of the organic EL element 40 of a bottom emission structure is demonstrated.

  The organic EL element 40 shown in FIG. 4 is configured by laminating the light emitting functional layer 3 and the counter electrode 5 in this order on the laminated body 10 ′ in the transparent electrode 10. Of these, the transparent electrode 10 of the present invention described above is characteristic as the transparent electrode. Therefore, the organic EL element 40 is configured as a bottom emission type that takes out the emitted light h from at least the transparent substrate 11 side.

<Constitutional layer of organic EL element>
Hereinafter, as a typical configuration in the organic EL element 40 of the present invention, the following configurations can be listed, but the configuration is not limited thereto.
(1) Anode / light emitting layer / cathode (2) Anode / light emitting layer / electron transport layer / cathode (3) Anode / hole transport layer / light emitting layer / cathode (4) Anode / hole transport layer / light emitting layer / electron Transport layer / cathode (5) anode / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode (6) anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / cathode ( 7) Anode / hole injection layer / hole transport layer / (electron blocking layer /) luminescent layer / (hole blocking layer /) electron transport layer / electron injection layer / cathode Among the above, the configuration of (7) is preferable. Although used, it is not limited to this. In the above-described typical element configuration, the layer excluding the anode and the cathode is the light emitting functional layer 3 having a light emitting property. Moreover, an anode or a cathode is comprised with either the transparent electrode 10 or the counter electrode 5 of this application.

<Light emitting functional layer 3>
The light emitting functional layer 3 is a layer sandwiched between the transparent electrode 10 and the counter electrode 5, and constitutes the organic EL element 40 together with the transparent electrode 10 and the counter electrode 5. This light emitting functional layer 3 may have a layer structure of a light emitting functional layer in a general organic EL element, and it is essential to have a light emitting layer 3a made of an organic material.

  In the above structure, the light emitting layer is formed of a single layer or a plurality of layers. When there are a plurality of light emitting layers, a non-light emitting intermediate layer may be provided between the light emitting layers. Further, if necessary, a hole blocking layer (also referred to as a hole blocking layer) or an electron injection layer (also referred to as a cathode buffer layer) may be provided between the light emitting layer and the cathode. An electron blocking layer (also referred to as an electron barrier layer) or a hole injection layer (also referred to as an anode buffer layer) may be provided therebetween.

The electron transport layer is a layer having a function of transporting electrons, and in a broad sense, an electron injection layer and a hole blocking layer are also included in the electron transport layer. The hole transport layer is a layer having a function of transporting holes, and in a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer.
Further, the electron transport layer and the hole transport layer may be composed of a plurality of layers.

(Tandem structure)
The organic EL element 40 may be an element having a so-called tandem structure in which a plurality of light emitting units including at least one light emitting layer are stacked.

  The light emitting unit is, for example, a configuration in which the anode and the cathode are excluded from the configurations (1) to (7) described in the above representative element configuration. And in the structure of the said organic EL element 40, it corresponds to the light emission functional layer 3 which has luminescent property.

As typical element configurations of the tandem structure, for example, the following configurations can be given.
(1.1) Anode / first light emitting unit / intermediate layer / second light emitting unit / cathode (2.2) anode / first light emitting unit / intermediate layer / second light emitting unit / intermediate layer / third light emitting unit / cathode

  Here, the first light emitting unit, the second light emitting unit, and the third light emitting unit may all be the same or different. Two light emitting units may be the same, and the remaining one may be different.

  Further, the plurality of light emitting units may be laminated directly or via an intermediate layer, and the intermediate layer is generally an intermediate electrode, an intermediate conductive layer, a charge generation layer, an electron extraction layer, a connection layer. A known material configuration can be used as long as it is also called an intermediate insulating layer and has a function of supplying electrons to the anode-side adjacent layer and holes to the cathode-side adjacent layer.

Examples of materials used for the intermediate layer include ITO (indium tin oxide), IZO (indium zinc oxide), ZnO ₂ , TiN, ZrN, HfN, TiO _x , VO _x , CuI, InN, GaN, Conductive inorganic compound layers such as CuAlO ₂ , CuGaO ₂ , SrCu ₂ O ₂ , LaB ₆ , RuO ₂ and Al, two-layer films such as Au / Bi ₂ O ₃ , SnO ₂ / Ag / SnO ₂ , ZnO / Multi-layer film such as Ag / ZnO, Bi ₂ O ₃ / Au / Bi ₂ O ₃ , TiO ₂ / TiN / TiO ₂ , TiO ₂ / ZrN / TiO ₂ , fullerenes such as C60, conductive organic substances such as oligothiophene Layer, metal phthalocyanines, metal-free phthalocyanines, metal porphyrins, metal-free porphyrins and other conductive organic compound layers, The present invention is not limited to these.

  Preferable configurations in the light emitting unit include, for example, the configurations (1) to (7) mentioned in the above representative element configurations, but the present invention is not limited to these.

  Specific examples of the tandem organic EL element include, for example, US Pat. No. 6,337,492, US Pat. No. 7,420,203, US Pat. No. 7,473,923, US Pat. No. 6,872, No. 472, U.S. Patent No. 6,107,734, U.S. Patent No. 6,337,492, International Publication No. 2005/009087, JP-A 2006-228712, JP-A 2006-24791, JP-A 2006-49393. No. 2006-49394, No. 2006-49396, No. 2011-96679, No. 2005-340187, No. 4711424, No. 34966681, No. 3884564, No. 4213169, JP 2010-192719, JP 2009-076929, JP 2008-078414, JP No. 007-059848, JP 2003-272860, JP 2003-045676, although elements configuration and construction materials described in WO 2005/094130, and the like, the present invention is not limited thereto.

  Hereinafter, each layer which comprises the organic EL element of this invention is demonstrated.

[Light emitting layer 3a]
The light emitting layer 3a according to the present invention is a layer that provides a field in which electrons and holes injected from an electrode or an adjacent layer are recombined to emit light via excitons, and the light emitting portion is a portion of the light emitting layer. Even in the layer, it may be the interface between the light emitting layer and the adjacent layer. The configuration of the light emitting layer 3a according to the present invention is not particularly limited as long as the requirements defined in the present invention are satisfied.

  The total film thickness of the light emitting layer 3a is not particularly limited, but the uniformity of the film to be formed, the application of unnecessary high voltage during light emission is prevented, and the stability of the emission color with respect to the driving current is improved. In view of the above, it is preferable to adjust to a range of 2 nm to 5 μm, more preferably to a range of 2 nm to 500 nm, and further preferably to a range of 5 nm to 200 nm.

  Moreover, it is preferable to adjust to the range of 2 nm-1 micrometer as a film thickness of each light emitting layer 3a, More preferably, it adjusts to the range of 2 nm-200 nm, More preferably, it adjusts to the range of 3 nm-150 nm.

  The light emitting layer 3a preferably contains a light emitting dopant (a light emitting dopant compound, a dopant compound, also simply referred to as a dopant) and a host compound (a matrix material, a light emitting host compound, also simply referred to as a host).

(1. Luminescent dopant)
The light emitting dopant used for the light emitting layer 3a will be described.
As the luminescent dopant, a fluorescent luminescent dopant (also referred to as a fluorescent dopant or a fluorescent compound) and a phosphorescent dopant (also referred to as a phosphorescent dopant or a phosphorescent compound) are preferably used. In the present invention, it is preferable that at least one light emitting layer contains a phosphorescent light emitting dopant.

  The concentration of the light emitting dopant in the light emitting layer 3a can be arbitrarily determined based on the specific dopant used and the requirements of the device, and is contained at a uniform concentration in the film thickness direction of the light emitting layer. Or may have an arbitrary concentration distribution.

  In addition, a plurality of kinds of light emitting dopants may be used in combination, or a combination of dopants having different structures, or a combination of a fluorescent light emitting dopant and a phosphorescent light emitting dopant may be used. Thereby, arbitrary luminescent colors can be obtained.

  The color emitted by the organic EL element is shown in FIG. 4.16 on page 108 of “New Color Science Handbook” (edited by the Japan Society for Color Science, University of Tokyo Press, 1985), with a spectral radiance meter CS-2000 (Konica Minolta Sensing ( It is determined by the color when the result measured by (made by Co., Ltd.) is applied to the CIE chromaticity coordinates.

In the organic EL element 40, it is also preferable that one or a plurality of light-emitting layers contain a plurality of light-emitting dopants having different emission colors and emit white light.
There are no particular limitations on the combination of the light-emitting dopants that exhibit white, and examples include blue and orange, and a combination of blue, green, and red.
The white color in the organic EL element 40 of the present invention means that the chromaticity in the CIE 1931 color system at 1000 cd / m ² is x = 0.39 ± 0. 09, preferably in the region of y = 0.38 ± 0.08.

(1-1. Phosphorescent dopant)
A phosphorescent dopant (hereinafter referred to as “phosphorescent dopant”) will be described.
The phosphorescent dopant according to the present invention is a compound in which light emission from an excited triplet is observed. Specifically, the phosphorescent dopant is a compound that emits phosphorescence at room temperature (25 ° C.) and has a phosphorescence quantum yield of 25. Although it is defined as a compound of 0.01 or more at ° C., a preferable phosphorescence quantum yield is 0.1 or more.

  The phosphorescence quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of Experimental Chemistry Course 4 of the 4th edition. Although the phosphorescence quantum yield in a solution can be measured using various solvents, the phosphorescence dopant according to the present invention achieves the phosphorescence quantum yield (0.01 or more) in any solvent. That's fine.

  There are two types of light emission of phosphorescent dopants in principle. One is the recombination of carriers on the host compound to which carriers are transported to generate an excited state of the host compound, and this energy is transferred to the phosphorescent dopant. It is an energy transfer type to obtain light emission from a phosphorescent dopant. The other is a carrier trap type in which a phosphorescent dopant serves as a carrier trap, and carrier recombination occurs on the phosphorescent dopant to emit light from the phosphorescent dopant. In any case, it is a condition that the excited state energy of the phosphorescent dopant is lower than the excited state energy of the host compound.

  The phosphorescent dopant can be appropriately selected from known materials used for the light emitting layer 3a of the organic EL element 40.

  Specific examples of known phosphorescent dopants that can be used in the present invention include compounds described in the following documents.

  Nature 395,151 (1998), Appl. Phys. Lett. 78, 1622 (2001), Adv. Mater. 19, 739 (2007), Chern. Mater. 17, 3532 (2005), Adv. Mater. 17, 1059 (2005 ), International Publication No. 2009100991, International Publication No. 2008101842, International Publication No. 2003030257, U.S. Patent Publication No. 2006835469, U.S. Patent Publication No. 20060202194, U.S. Patent Publication No. 20070087321, and U.S. Patent Publication No. 20050246673.

  Inorg. Chern. 40, 1704 (2001), Chern. Mater. 16, 2480 (2004), Adv. Mater. 16, 2003 (2004), Angew. Chern. Lnt. Ed. 2006, 45, 7800, Appl. Phys Lett. 86, 153505 (2005), Chern. Lett. 34, 592 (2005), Chern. Commun. 2906 (2005), Inorg. Chern. 42, 1248 (2003), International Publication No. 2009050290, International Publication No. 2002015645, International Publication No. 2009000673, United States Patent Publication No. 20020034656, United States Patent No. 7332232, United States Patent Publication No. 20090108737, United States Patent Publication No. 20090039776, United States Patent No. 6921915, United States Patent No. 6,687,266, United States Patent Publication No. 20070190359, U.S. Patent Publication No. 20060860570, U.S. Publication No. 20090165846, U.S. Patent Publication No. 20080015355, U.S. Pat. No. 7,250,226. , U.S. Patent No. 7396598, U.S. Patent Publication No. 20060263635, U.S. Patent Publication No. 20030138657, U.S. Patent Publication No. 20030152802, U.S. Patent No. 7,090,928.

  Angew. Chern. Lnt. Ed. 47, 1 (2008), Chern. Mater. 18, 5119 (2006), Inorg. Chern. 46, 4308 (2007), Organometallics 23, 3745 (2004), Appl. Phys. Lett 74, 1361 (1999), International Publication No. 2002002714, International Publication No. 2006009024, International Publication No. 200606056418, International Publication No. 2005019373, International Publication No. 200500513873, International Publication No. 200500513873, International Publication No. 20070043380, International Patent Publication No. 2006082742, United States Patent Publication No. 20060251923, United States Patent Publication No. 20050260441, United States Patent No. 7393599, United States Patent No. 7,534,505, United States Patent No. 7,445,855, United States Patent Publication No. 20070190359, United States Patent Publication No. 20080297033. No., US Pat. No. 7,338,722, US Patent Publication No. 20020134984, U.S. Pat. No. 7,279,704, U.S. Pat. Publication No. 2006098120, U.S. Pat. Publication No. 2006103874.

  International Publication No. 2005076380, International Publication No. 20130032663, International Publication No. 2008140115, International Publication No. 20077052431, International Publication No. 20111134013, International Publication No. 2011157339, International Publication No. 20100086089, International Publication No. 20101313646, International Publication No. 2012020327, International Publication No. 20111051404, International Publication No. 2011004639, International Publication No. 20111073149, U.S. Patent Publication No. 20122228583, U.S. Patent Publication No. 201212212126, JP2012-0697737, JP2012-195554, JP 2009-114086, JP 2003-81988, JP 2002-302671, JP 2002-363552, and the like.

  Among these, a preferable phosphorescent dopant includes an organometallic complex having Ir as a central metal. More preferably, a complex containing at least one coordination mode of a metal-carbon bond, a metal-nitrogen bond, a metal-oxygen bond, or a metal-sulfur bond is preferable.

  Hereinafter, although the specific examples D1-D81 of the well-known phosphorescence dopant applicable to the light emitting layer 3a are given, this invention is not limited to these.

(1-2. Fluorescent luminescent dopant)
A fluorescence emitting dopant (hereinafter referred to as “fluorescence dopant”) will be described.

  The fluorescent dopant is a compound that can emit light from an excited singlet, and is not particularly limited as long as light emission from the excited singlet is observed.

Examples of the fluorescent dopant include anthracene derivatives, pyrene derivatives, chrysene derivatives, fluoranthene derivatives, perylene derivatives, fluorene derivatives, arylacetylene derivatives, styrylarylene derivatives, styrylamine derivatives, arylamine derivatives, boron complexes, coumarin derivatives, pyran derivatives, Examples include cyanine derivatives, croconium derivatives, squalium derivatives, oxobenzanthracene derivatives, fluorescein derivatives, rhodamine derivatives, pyrylium derivatives, perylene derivatives, polythiophene derivatives, and rare earth complex compounds.
In recent years, light emitting dopants utilizing delayed fluorescence have been developed, and these may be used.

  Specific examples of those using delayed fluorescence as the fluorescent dopant include, for example, compounds described in International Publication No. 2011/156793, Japanese Patent Application Laid-Open No. 2011-213643, Japanese Patent Application Laid-Open No. 2010-93181, etc. The present invention is not limited to these.

(2. Host compound)
The host compound is a compound mainly responsible for charge injection and transport in the light emitting layer 3a, and its own light emission is not substantially observed in the organic EL element.
Preferably, it is a compound having a phosphorescence quantum yield of phosphorescence emission of less than 0.1 at room temperature (25 ° C.), more preferably a compound having a phosphorescence quantum yield of less than 0.01. Moreover, it is preferable that the mass ratio in the layer is 20% or more among the compounds contained in a light emitting layer.

  Moreover, it is preferable that the excited state energy of a host compound is higher than the excited state energy of the light emission dopant contained in the same layer.

  A host compound may be used independently or may be used in combination of multiple types. By using a plurality of types of host compounds, it is possible to adjust the movement of charges, and the organic EL element 40 can be made highly efficient.

  There is no restriction | limiting in particular as a host compound used for the light emitting layer 3a, The compound conventionally used with an organic EL element can be used. For example, it may be a low molecular compound, a high molecular compound having a repeating unit, or a compound having a reactive group such as a vinyl group or an epoxy group.

As a known host compound, while having a hole transporting ability or an electron transporting ability, it is possible to prevent the light emission from becoming longer wavelength, and from the viewpoint of stability against heat generation when the organic EL element 40 is driven at a high temperature or during element driving. It is preferable to have a high glass transition temperature (Tg). As a host compound, it is preferable that Tg is 90 degreeC or more, More preferably, it is 120 degreeC or more.
Here, a glass transition point (Tg) is a value calculated | required by the method based on JIS-K-7121 using DSC (Differential Scanning Colorimetry: Differential scanning calorimetry).

  Specific examples of known host compounds used in the organic EL element 40 include, but are not limited to, compounds described in the following documents.

  JP-A-2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860, 2002-334787, 2002-15871, 2002-334788, 2002-43056, 2002-334789, 2002-75645, 2002-338579, 2002-105445 gazette, 2002-343568 gazette, 2002-141173 gazette, 2002-352957 gazette, 2002-203683 gazette, 2002-363227 gazette, 2002-231453 gazette, No. 003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-286061, No. 2002-280183, No. 2002-299060, No. 2002. -302516, 2002-305083, 2002-305084, 2002-308837, US Patent Publication No. 20030175553, United States Patent Publication No. 20060280965, United States Patent Publication No. 20050112407, United States Patent Publication 20090017330, U.S. Patent Publication No. 20090030202, U.S. Patent Publication No. 20050238919, International Publication No. 2001039234, International Publication No. 200902126, International Publication No. No. 8056746, International Publication No. 2004093207, International Publication No. 2005089025, International Publication No. 20077063796, International Publication No. 2007076754, International Publication No. 2004078822, International Publication No. 2005030900, International Publication No. 20060146966, International Publication No. 2009086028 International Publication No. 2009003898, International Publication No. 20122023947, Japanese Unexamined Patent Application Publication No. 2008-074939, Japanese Unexamined Patent Application Publication No. 2007-254297, EP2034538, and the like.

[Electron transport layer]
Electron transport used for the organic EL element 40 is made of a material having a function of transporting electrons and has a function of transmitting electrons injected from the cathode to the light emitting layer 3a.
The electron transport material may be used alone or in combination of two or more. Although there is no restriction | limiting in particular about the total thickness of an electron carrying layer, Usually, it is the range of 2 nm-5 micrometers, More preferably, it is 2 nm-500 nm, More preferably, it is 5 nm-200 nm.

  Further, in the organic EL element 40, when the light generated in the light emitting layer 3a is extracted from the electrode, the light extracted directly from the light emitting layer 3a and the light extracted after being reflected by the electrode from which the light is extracted and the electrode located at the counter electrode Is known to cause interference. When light is reflected by the cathode, this interference effect can be efficiently utilized by appropriately adjusting the total film thickness of the electron transport layer between several nanometers and several micrometers.

On the other hand, when the thickness of the electron transport layer is increased, the voltage is likely to increase. Therefore, particularly when the thickness is large, the electron mobility of the electron transport layer is preferably 10 ⁻⁵ cm ² / Vs or more. .

  The material used for the electron transporting layer (hereinafter referred to as an electron transporting material) may be any of electron injecting or transporting properties and hole blocking properties, and can be selected from conventionally known compounds. Can be selected and used.

  Examples thereof include nitrogen-containing aromatic heterocyclic derivatives, aromatic hydrocarbon ring derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, silole derivatives, and the like.

Examples of the nitrogen-containing aromatic heterocyclic derivatives include carbazole derivatives, azacarbazole derivatives (one or more carbon atoms constituting the carbazole ring are substituted with nitrogen atoms), pyridine derivatives, pyrimidine derivatives, pyrazine derivatives, pyridazine derivatives, triazine derivatives. Quinoline derivatives, quinoxaline derivatives, phenanthroline derivatives, azatriphenylene derivatives, oxazole derivatives, thiazole derivatives, oxadiazole derivatives, thiadiazole derivatives, triazole derivatives, benzimidazole derivatives, benzoxazole derivatives, benzthiazole derivatives, and the like.
Examples of the aromatic hydrocarbon ring derivative include naphthalene derivatives, anthracene derivatives, triphenylene and the like.

In addition, a metal complex having a quinolinol skeleton or a dibenzoquinolinol skeleton as a ligand, for example, tris (8-quinolinol) aluminum (Alq ₃ ), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7 -Dibromo-8-quinolinol) aluminum, tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), etc., and metal complexes thereof A metal complex in which the central metal is replaced with In, Mg, Cu, Ca, Sn, Ga, or Pb can also be used as an electron transporting material.

In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transporting material. In addition, the distyrylpyrazine derivative exemplified as the material of the light emitting layer can also be used as an electron transport material, and an inorganic semiconductor such as n-type-Si, n-type-SiC, etc. as in the case of the hole injection layer and the hole transport layer. Can also be used as an electron transporting material.
In addition, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

  In the organic EL element 40, the electron transport layer may be doped with a doping material as a guest material to form an electron transport layer having a high n property (electron rich). Examples of the doping material include n-type dopants such as metal complexes and metal compounds such as metal halides. Specific examples of the electron transport layer having such a configuration include, for example, JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, 2001-102175, J. Appl. Phys., 95, 5773 (2004) and the like.

  Specific examples of known preferable electron transport materials used for the organic EL element 40 include compounds described in the following documents, but the present invention is not limited thereto.

  U.S. Patent No. 6,528,187, U.S. Patent No. 7,230,107, U.S. Patent Publication No. 20050025993, U.S. Patent Publication No. 2004036077, U.S. Patent Publication No. 200901115316, U.S. Patent Publication No. 20090101870, U.S. Patent Publication No. 20090195554, International Publication No. 2003060956, WO200008132085, Appl. Phys. Lett. 75, 4 (1999), Appl. Phys. Lett. 79, 449 (2001), Appl. Phys. Lett. 81, 162 (2002), Appl. Phys. Lett. 81, 162 (2002), Appl. Phys. Lett. 79, 156 (2001), US Patent No. 7964293, US Patent Publication No. 20090302202, International Publication No. 20040980975, International Publication No. 2004063159, International Publication No. 20050885387, International Publication No. 20060606791, International Publication No. 2007 86552, International Publication No. 20080081690, International Publication No. 2009090442, International Publication No. 2009066779, International Publication No. 2009054253, International Publication No. 20101086935, International Publication No. 2010150593, International Publication No. 20110047707, EP23111826 2010-251675, JP2009-209133, JP2009-124114, JP2008-277810, JP2006-156445, JP2005-340122, JP2003-45662, JP2003 No. 31367, JP-A No. 2003-282270, International Publication No. 201212115034, and the like.

  More preferable electron transport materials include pyridine derivatives, pyrimidine derivatives, pyrazine derivatives, triazine derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, carbazole derivatives, azacarbazole derivatives, and benzimidazole derivatives.

  In addition, an electron transport material may be used independently and may be used in combination of multiple types.

[Hole blocking layer]
The hole blocking layer is a layer having a function of an electron transport layer in a broad sense. Preferably, it is made of a material having a function of transporting electrons and a small ability to transport holes. By blocking holes while transporting electrons, the recombination probability of electrons and holes can be improved.
Moreover, the structure of the above-mentioned electron carrying layer can be used as a hole-blocking layer as needed.

  The hole blocking layer provided in the organic EL element 40 is preferably provided adjacent to the cathode side of the light emitting layer 3a.

In the organic EL element 40, the thickness of the hole blocking layer is preferably in the range of 3 to 100 nm, and more preferably in the range of 5 to 30 nm.
As the material used for the hole blocking layer, the material used for the above-described electron transport layer is preferably used, and the material used as the above-described host compound is also preferably used for the hole blocking layer.

[Electron injection layer]
The electron injection layer (also referred to as “cathode buffer layer”) is a layer provided between the cathode and the light emitting layer in order to lower the driving voltage and improve the light emission luminance. An example of an electron injection layer is described in the second chapter, Chapter 2, “Electrode Materials” (pages 123 to 166) of “Organic EL devices and their industrialization front line (issued by NTT Corporation on November 30, 1998)”. Have been described.

In the organic EL element 40, the electron injection layer is provided as necessary, and is provided between the cathode and the light emitting layer or between the cathode and the electron transport layer as described above.
The electron injection layer is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 nm, although it depends on the material. Moreover, the nonuniform film | membrane in which a constituent material exists intermittently may be sufficient.

Details of the electron injection layer are also described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specific examples of materials preferably used for the electron injection layer include metals typified by strontium and aluminum, alkali metal compounds typified by lithium fluoride, sodium fluoride, and potassium fluoride, magnesium fluoride, and fluoride. Examples include alkaline earth metal compounds typified by calcium, metal oxides typified by aluminum oxide, metal complexes typified by lithium 8-hydroxyquinolate (Liq), and the like. Moreover, it is also possible to use the above-mentioned electron transport material.
Moreover, the material used for said electron injection layer may be used independently, and may be used in combination of multiple types.

[Hole transport layer]
The hole transport layer is made of a material having a function of transporting holes. The hole transport layer is a layer having a function of transmitting holes injected from the anode to the light emitting layer 3a.

  In the organic EL element 40, the total film thickness of the hole transport layer is not particularly limited, but is usually in the range of 5 nm to 5 μm, more preferably 2 nm to 500 nm, and further preferably 5 nm to 200 nm.

  The material used for the hole transport layer (hereinafter referred to as a hole transport material) only needs to have either a hole injecting or transporting property or an electron blocking property. As the hole transport material, an arbitrary material can be selected and used from conventionally known compounds. The hole transport material may be used alone or in combination of two or more.

  Hole transport materials include, for example, porphyrin derivatives, phthalocyanine derivatives, oxazole derivatives, oxadiazole derivatives, triazole derivatives, imidazole derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, hydrazone derivatives, stilbene derivatives, polyarylalkane derivatives, tria Reelamine derivatives, carbazole derivatives, indolocarbazole derivatives, isoindole derivatives, acene derivatives such as anthracene and naphthalene, fluorene derivatives, fluorenone derivatives, polyvinyl carbazole, polymer materials having aromatic amine introduced in the main chain or side chain, or Oligomer, polysilane, conductive polymer or oligomer (eg, PEDOT: PSS, aniline copolymer, polyaniline, polythiophene, etc.), etc. And the like.

  Examples of the triarylamine derivative include a benzidine type typified by α-NPD, a starburst type typified by MTDATA, and a compound having fluorene or anthracene in the triarylamine linking core part.

  In addition, hexaazatriphenylene derivatives described in JP-T-2003-519432 and JP-A-2006-135145 can also be used as the hole transport material.

Furthermore, a hole transport layer having a high p property doped with impurities can also be used. For example, the structures described in JP-A-4-297076, JP-A-2000-196140, 2001-102175, J. Appl. Phys., 95, 5773 (2004), etc. are used as holes. It can also be applied to the transport layer.
Also, so-called p-type hole transport materials and p-type materials described in JP-A-11-251067 and J. Huang et.al. (Applied Physics Letters 80 (2002), p. 139). Inorganic compounds such as -Si and p-type -SiC can also be used. Further, ortho-metalated organometallic complexes having Ir or Pt as the central metal as typified by Ir (ppy) ₃ are also preferably used.

  Although the above-mentioned materials can be used as the hole transport material, a triarylamine derivative, a carbazole derivative, an indolocarbazole derivative, an azatriphenylene derivative, an organometallic complex, or an aromatic amine is introduced into the main chain or side chain. The polymer materials or oligomers used are preferably used.

  Specific examples of the hole transport material used for the organic EL element 40 include, but are not limited to, the compounds described in the following documents in addition to the documents listed above.

  Appl. Phys. Lett. 69, 2160 (1996), J. Lμmin. 72-74, 985 (1997), Appl. Phys. Lett. 78, 673 (2001), Appl. Phys. Lett. 90, 183503 (2007) ), Appl. Phys. Lett. 90, 183503 (2007), Appl. Phys. Lett. 51, 913 (1987), Synth. Met. 87, 171 (1997), Synth. Met. 91, 209 (1997), Synth. Met. 111,421 (2000), SID SymposiμmDigest, 37, 923 (2006), J. Mater. Chern. 3, 319 (1993), Adv. Mater. 6, 677 (1994), Chern. Mater. 15,3148 (2003), U.S. Patent Publication No. 20030162053, U.S. Patent Publication No. 200201558242, U.S. Patent Publication No. 20060240279, U.S. Patent Publication No. 20080220265, U.S. Patent No. 5061569, International Publication No. 2007002683, International Publication No. 2009018099, EP650955, U.S. Patent Publication No. 20080124572, U.S. Patent Publication No. 2007078938, U.S. Patent Publication No. 2008 No. 106,190, U.S. Patent Publication No. 20080018221, WO 2012115034, JP-T 2003-519432, JP No. 2006-135145 is US Patent Application No. 13/585981.

  The hole transport material may be used alone or in combination of two or more.

[Electron blocking layer]
The electron blocking layer is a layer having a function of a hole transport layer in a broad sense. Preferably, it is made of a material having a function of transporting holes and a small ability to transport electrons. The electron blocking layer can improve the probability of recombination of electrons and holes by blocking electrons while transporting holes.

  Moreover, the structure of the above-mentioned hole transport layer can be used as an electron blocking layer of the organic EL element 40 as necessary. The electron blocking layer provided in the organic EL element 40 is preferably provided adjacent to the anode side of the light emitting layer 3a.

The thickness of the electron blocking layer is preferably in the range of 3 to 100 nm, more preferably in the range of 5 to 30 nm.
As the material used for the electron blocking layer, the materials used for the above-described hole transport layer can be preferably used. Moreover, the material used as the above-mentioned host compound can also be preferably used as the electron blocking layer.

[Hole injection layer]
The hole injection layer (also referred to as “anode buffer layer”) is a layer provided between the anode and the light emitting layer in order to lower the driving voltage and improve the light emission luminance. An example of the hole injection layer is “Organic EL device and its industrialization front line (November 30, 1998, issued by NTT)”, Chapter 2, Chapter 2, “Electrode material” (pages 123-166). It is described in.
The hole injection layer is provided as necessary, and is provided between the anode and the light emitting layer 3a or between the anode and the hole transport layer as described above.

The details of the hole injection layer are also described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like.
Examples of the material used for the hole injection layer include the materials used for the hole transport layer described above. Among them, phthalocyanine derivatives typified by copper phthalocyanine, hexaazatriphenylene derivatives as described in JP-T-2003-519432 and JP-A-2006-135145, metal oxides typified by vanadium oxide, amorphous carbon, polyaniline ( Preferred are conductive polymers such as emeraldine) and polythiophene, orthometalated complexes represented by tris (2-phenylpyridine) iridium complex, and triarylamine derivatives.
The materials used for the hole injection layer described above may be used alone or in combination of two or more.

[Contains]
The light emitting functional layer 3 constituting the organic EL element 40 may further contain other inclusions.
Examples of the inclusion include halogen elements such as bromine, iodine, and chlorine, halogenated compounds, alkali metals such as Pd, Ca, and Na, alkaline earth metals, transition metal compounds, complexes, and salts.

The content of the inclusion can be arbitrarily determined, but is preferably 1000 ppm or less, more preferably 500 ppm or less, and even more preferably 50 ppm or less with respect to the total mass% of the contained layer. .
However, it is not within this range depending on the purpose of improving the transportability of electrons and holes or the purpose of favoring the exciton energy transfer.

[Method of forming light emitting functional layer 3]
A method for forming a light emitting functional layer (hole injection layer, hole transport layer, light emitting layer 3a, hole blocking layer, electron transport layer, electron injection layer, etc.) of the organic EL element 40 will be described.
There is no restriction | limiting in particular in the formation method of the light emission functional layer 3, It can form by conventionally well-known, for example, a vacuum evaporation method, a wet method (wet process) etc.

  Examples of the wet method include a spin coating method, a casting method, an ink jet method, a printing method, a die coating method, a blade coating method, a roll coating method, a spray coating method, a curtain coating method, and an LB method (Langmuir-Blodgett method). From the viewpoint of obtaining a homogeneous thin film easily and high productivity, a method having high suitability for a roll-to-roll method such as a die coating method, a roll coating method, an ink jet method, or a spray coating method is preferable.

Examples of the liquid medium for dissolving or dispersing the material of the light emitting functional layer in the wet method include ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, halogenated hydrocarbons such as dichlorobenzene, toluene, xylene, and the like. Aromatic hydrocarbons such as mesitylene and cyclohexylbenzene, aliphatic hydrocarbons such as cyclohexane, decalin and dodecane, and organic solvents such as DMF and DMSO can be used.
Moreover, it can disperse | distribute by dispersion methods, such as an ultrasonic wave, high shear force dispersion | distribution, and media dispersion | distribution.

When a vapor deposition method is employed for forming each layer constituting the light emitting functional layer 3, the vapor deposition conditions vary depending on the type of compound used, etc., but generally a boat heating temperature of 50 ° C to 450 ° C and a degree of vacuum of ^10-6 Pa to ^10-6 . ^-2 Pa, vapor deposition rate of 0.01 nm / second to 50 nm / second, substrate temperature of -50 ° C to 300 ° C, film thickness of 0.1 nm to 5 µm, preferably 5 nm to 200 nm.

The organic EL element 40 is preferably formed from the light emitting functional layer 3 to the counter electrode 5 consistently by a single evacuation, but may be taken out halfway and subjected to different film forming methods. In that case, it is preferable to perform the work in a dry inert gas atmosphere.
Different formation methods may be applied for each layer.

<Transparent electrode 10>
The transparent electrode 10 is the transparent electrode 10 of FIG. 1 described above, and constitutes an anode or a cathode of the organic EL element 40. In addition, in this embodiment, although comprised using the transparent electrode 10 which concerns on 1st Embodiment as a transparent electrode, you may comprise using the transparent electrode 20 or 30 of 2nd Embodiment or 3rd Embodiment. .

<Counter electrode 5>
The counter electrode 5 is an electrode that constitutes an anode or a cathode of the organic EL element 40, and is an electrode provided on one main surface of the transparent electrode 10 via the light emitting functional layer 3. The counter electrode 5 is used as a cathode with respect to the light emitting functional layer 3 of the organic EL element 40 when the transparent electrode 10 is an anode, and is used as an anode when the transparent electrode 10 is a cathode. For this reason, at least the interface layer on the side in contact with the light emitting functional layer 3 is made of a material suitable as a cathode or an anode.

  Such a counter electrode 5 is configured as a reflective electrode that reflects, for example, emitted light h generated in the light emitting layer 3 a of the light emitting functional layer 3 to the light extraction surface 11 a side of the transparent substrate 11. The counter electrode 5 may be transmissive to visible light. In this case, the emitted light h can be extracted from the counter electrode 5 side.

  Here, the anode and the cathode constituting the counter electrode 5 described above are as follows.

[anode]
As the anode in the organic EL element 40, an electrode material made of a metal, an alloy, an electrically conductive compound, and a mixture thereof having a high work function (4 eV or more, preferably 4.5 V or more) is used. Specific examples of such electrode materials include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO. Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ —ZnO) capable of forming a transparent conductive film may be used.

  As the anode, a thin film is formed by depositing these electrode materials by a method such as vapor deposition or sputtering, and a pattern having a desired shape is formed by a photolithography method. Alternatively, when pattern accuracy is not so required (about 100 μm or more), the pattern may be formed through a mask having a desired shape when the electrode material is formed by vapor deposition or sputtering.

  Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film-forming methods, such as a printing system and a coating system, can also be used. The sheet resistance as the anode is several hundred Ω / sq. The following is preferred.

  Although the thickness of the anode depends on the material, it is usually selected in the range of 10 nm to 1 μm, preferably 10 nm to 200 nm in consideration of transparency or reflectivity.

[cathode]
As the cathode, an electrode substance made of a metal having a low work function (4 eV or less) (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, aluminum, rare earth metals and the like.

Among these, a mixture of an electron injecting metal and a second metal having a work function value larger and more stable than that of the electron injecting metal, for example, magnesium / Silver mixtures, magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred.

  The cathode can be produced using the above electrode material by vapor deposition or sputtering. The sheet resistance of the cathode is several hundred Ω / sq. The following is preferred.

  Although the thickness of the cathode depends on the material, it is usually selected in the range of 10 nm to 5 μm, preferably 50 nm to 200 nm in consideration of transparency or reflectivity.

  Further, the counter electrode 5 may be configured by the laminated body 10 ′ in the transparent electrode 10 described above. This example will be described below.

  FIG. 5 is a schematic cross-sectional view showing a configuration in which the counter electrode of the organic EL element of the present embodiment is a laminate having a two-layer structure. The organic EL element 50 shown in this figure is different from the organic EL element 40 described with reference to FIG. 4 in that the counter electrode 7 is a laminate 10 ′ having a two-layer structure in the transparent electrode 10, Other configurations are the same. For this reason, the same code | symbol is attached | subjected to the same component and the overlapping description is abbreviate | omitted.

  That is, the counter electrode 7 of the organic EL element 50 shown in FIG. 5 has a configuration in which the compound layer 1a and the metal layer 2 are laminated in this order from the light emitting functional layer 3 side.

  Moreover, although the thickness of the metal layer 2 in the counter electrode 7 depends on the material, it is usually 4 nm to 5 μm and is selected in consideration of transparency or reflectivity. When the transmissive counter electrode 7 is configured, the metal layer preferably has a film thickness in the range of 4 nm to 10 nm. When the counter electrode 7 having reflectivity is configured, the thickness of the metal layer is preferably in the range of 50 nm to 200 nm. In addition, when the counter electrode 7 has transparency, the organic EL element 50 can be used as a double-sided light emitting type.

  When the counter electrode 7 is configured to have transparency, silver oxide is formed between the compound layer 1a and the metal layer 2 in the same manner as the transparent electrode 10 shown in FIG. The smoothness of the surface is improved by the interaction of silver and the silver constituting the metal layer 2 or an alloy containing silver as a main component, and the metal layer 2 having a high surface smoothness with a uniform thickness even though it is thin. Can be formed. In other words, the counter electrode 7 has both sufficient conductivity and light transmissivity by improving the smoothness of the electrode surface.

  Further, when the counter electrode 7 having reflectivity is configured, the above-described silver oxide and the silver constituting the metal layer 2 or the silver-based alloy interact with each other, so that the uniform thickness can be obtained. A simple metal layer 2 can be formed. For this reason, since the counter electrode 7 has the high-quality metal layer 2, the reflectance toward the light extraction surface 11a is improved.

  In addition, such a counter electrode 7 is low in cost because it does not use indium (In), which is a rare metal, and has excellent long-term reliability because it does not use a chemically unstable material such as ZnO. It will be.

  In addition, since the compound layer 1a which comprises the counter electrode 7 is pinched | interposed into the metal layer 2 used as a substantial electrode, it also comprises the light emission functional layer 3. FIG. Therefore, since the compound exemplified above as the compound layer 1a has a low hole injection property, it is preferably used as a cathode when the counter electrode 7 is formed of the laminate 10 '.

  The sealing means, protective film, protective plate, light extraction technology, and light collecting sheet that can be applied to the organic EL element 40 will be described below in this order, but these can also be applied to the organic EL element 50 shown in FIG. .

(External extraction efficiency)
The external extraction efficiency of light emission of the organic EL element at room temperature is preferably 1% or more, and more preferably 5% or more.
Here, external extraction quantum efficiency (%) = number of photons emitted to the outside of the organic EL element / number of electrons flowed to the organic EL element × 100.
In addition, a hue improvement filter such as a color filter may be used in combination, or a color conversion filter that converts the emission color from the organic EL element into multiple colors using a phosphor may be used in combination.

[Sealing]
Although the organic EL element emits light well with a small amount of power, it is weak against moisture and a non-light emitting portion is formed due to moisture absorption, so that it is preferably sealed with a sealing member.

  As a sealing means applied to the sealing of the organic EL element of the present invention, for example, a method of adhering a sealing member, a counter electrode and a transparent substrate with an adhesive can be mentioned. As a sealing member, it should just be arrange | positioned so that the display area | region of an organic EL element may be covered, and it may be concave plate shape or flat plate shape. Moreover, the transparency and electrical insulation of the sealing member are not particularly limited.

Specific examples include a glass plate, a polymer plate / film, and a metal plate / film. Examples of the glass plate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone. Examples of the metal plate include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium, and tantalum. .
For processing the sealing member into a concave shape, sandblasting, chemical etching, or the like is used.

In order to reduce the thickness of the organic EL element, it is preferable to use a polymer film or a metal film. Furthermore, the polymer film has an oxygen permeability measured by a method according to JIS K 7126-1987 of 1 × 10 ⁻³ ml / (m ² / 24h) or less, and was measured by a method according to JIS K 7129-1992. water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)%) is preferably at ^{1 × 10 -3 g / (m} 2 / 24h) or less.

  Examples of the adhesive include photo-curing and thermosetting adhesives having reactive vinyl groups such as acrylic acid oligomers and methacrylic acid oligomers, and moisture-curing adhesives such as 2-cyanoacrylate. be able to. Moreover, heat | fever and chemical curing types (two-component mixing), such as an epoxy type, can be mentioned. Moreover, hot-melt type polyamide, polyester, and polyolefin can be mentioned. Moreover, a cationic curing type ultraviolet curing epoxy resin adhesive can be mentioned.

  In addition, since an organic EL element may deteriorate by heat processing, what can be adhesive-hardened from room temperature to 80 degrees C or less is preferable. Further, a desiccant may be dispersed in the adhesive. Application | coating of the adhesive agent to a sealing part may use commercially available dispenser, and may print like screen printing.

  In addition, the counter electrode and the light emitting functional layer are covered on the counter electrode on the side facing the transparent substrate with the light emitting functional layer interposed therebetween, and an inorganic or organic layer is formed in contact with the transparent substrate, thereby sealing It can also be a membrane. In this case, the material for forming the sealing film may be any material having a function of suppressing entry of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used.

  Furthermore, in order to improve the brittleness of the sealing film, it is preferable to have a laminated structure of an inorganic layer and a layer made of an organic material, like the above-described barrier film. The method for forming these films is not particularly limited. For example, vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma A polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

  Injecting a gas phase with an inert gas such as nitrogen or argon or a liquid phase with an inert liquid such as fluorinated hydrocarbon or silicon oil into the gap between the sealing member and the display area of the organic EL element. Is preferred. Further, the gap between the sealing member and the display area of the organic EL element can be evacuated.

  Furthermore, a hygroscopic compound can be enclosed in the gap between the sealing member and the display area of the organic EL element.

  Examples of the hygroscopic compound include metal oxides such as sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, and aluminum oxide, sulfates such as sodium sulfate, calcium sulfate, magnesium sulfate, and cobalt sulfate, calcium chloride, Metal halides such as magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide, magnesium iodide, barium perchlorate, and perchloric acids such as magnesium perchlorate Can be mentioned. Anhydrous salts are preferably used as sulfates, metal halides and perchloric acids.

[Protective film, protective plate]
A protective film or a protective plate may be provided outside the sealing film or sealing film for sealing the organic EL element in order to increase the mechanical strength of the element. In particular, when the organic EL element is sealed with a sealing film, the mechanical strength is not necessarily high, and thus a protective film or a protective plate is preferably provided. As a material that can be used as the protective film or the protective plate, for example, a glass plate, a polymer plate / film, a metal plate / film, or the like can be used in the same manner as the sealing member described above. As the protective film or protective plate, it is preferable to use a polymer film that can be reduced in weight and thickness.

[Light extraction improvement technology]
The organic EL element preferably has good light extraction efficiency. Therefore, as described above, the transparent electrode of the organic EL element 40 may be constituted by the transparent electrode 30 having the scattering layer 1c shown in FIG. 3, and the light extraction efficiency of the organic EL element is improved. May have other configurations.

  The organic EL element emits light inside a layer having a refractive index higher than that of air (within a refractive index of about 1.6 to 2.1), and 15% to 20% of light generated in the light emitting layer. It is generally known that it can only be removed. The reason for this is that light incident on the interface (for example, the interface between the transparent substrate and air) at an angle θ greater than the critical angle causes total reflection and is difficult to extract to the outside of the element, or a laminate of the transparent substrate and the transparent electrode. Alternatively, light is totally reflected between the transparent electrode and the light emitting layer, and the light is guided through the laminate or the light emitting layer, and as a result, the light escapes in the direction of the side surface of the element.

  As a method for improving the light extraction efficiency of the organic EL element, for example, a method of forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (for example, US Pat. No. 4,774,435) A method for improving the efficiency by giving the substrate a light collecting property (for example, JP-A-63-314795), a method for forming a reflective surface on the side surface of the element (for example, JP-A-1-220394) ), A method of introducing a flat layer having an intermediate refractive index between the substrate and the light emitter to form an antireflection film (for example, Japanese Patent Application Laid-Open No. 62-172691); A method of introducing a flat layer having a low refractive index (for example, Japanese Patent Application Laid-Open No. 2001-202827), and forming a diffraction grating between the substrate, the transparent electrode layer and the light emitting layer (including between the substrate and the outside) how to( No. 11-283751 JP), and the like.

In the organic EL element of this embodiment, it can use combining the above-mentioned method. In particular, a method of introducing a flat layer having a lower refractive index than the transparent substrate between the transparent substrate and the light emitting layer, or a method of forming a diffraction grating between layers can be suitably used.
In the organic EL element, the light extraction efficiency can be further improved by combining these means.

  For example, in the organic EL element 40, when a low refractive index medium having a thickness longer than the wavelength of light transmitted between the stacked body 10 ′ and the transparent substrate 11 is formed, the light emitted from the stacked body 10 ′ The lower the refractive index, the higher the extraction efficiency to the outside of the element.

  Examples of the low refractive index layer formed of a low refractive index medium include airgel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of the transparent substrate is generally in the range of about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.5 or less. Furthermore, it is preferable that it is 1.35 or less.

  In addition, the thickness of the low refractive index layer is preferably at least twice the wavelength of light transmitted through the medium. This is because when the thickness of the low refractive index layer is about the wavelength of light, the electromagnetic wave exuded by evanescent enters the layer adjacent to the light extraction surface side of the low refractive index layer. This is because the effect of the rate layer is diminished.

[Condenser sheet]
The organic EL element is provided with, for example, a microlens array or a so-called condensing sheet on the light extraction surface side, thereby condensing light in a specific direction, for example, in the front direction with respect to the light emitting surface of the element, thereby increasing the luminance in the specific direction. Can do.

  Moreover, in order to control the light emission angle from an organic EL element, you may use a light-diffusion plate and a film together with a condensing sheet. For example, a diffusion film (light-up) manufactured by Kimoto Co., Ltd. can be used. For example, when the transparent electrode 30 having the scattering layer 1c shown in FIG. 3 is used as the transparent electrode of the organic EL element 40, the above sheet can be used in addition to the scattering layer 1c.

  As an example of the microlens array, square pyramids having a side of 30 μm and an apex angle of 90 degrees are arranged two-dimensionally on the light extraction surface side of the substrate. One side is preferably within a range of 10 to 100 μm. If it becomes smaller than this, the effect of diffraction will generate | occur | produce and color, and if too large, thickness will become thick and is not preferable.

  As the condensing sheet, for example, a sheet that is put into practical use in an LED backlight of a liquid crystal display device can be used. As such a sheet, for example, a brightness enhancement film (BEF) manufactured by Sumitomo 3M Limited can be used. As a prism sheet, for example, a shape in which a stripe having a triangular cross section with a vertex angle of 90 degrees and a pitch of 50 μm is formed on a base material, a shape in which the vertex angle is rounded, a shape in which the pitch is randomly changed, and other Shapes can be used.

[Usage]
The organic EL element can be applied to electronic devices such as display devices, displays, and various light emission sources.

  Examples of light-emitting light sources include lighting devices such as home lighting and interior lighting, backlights for clocks and liquid crystals, signboard advertisements, traffic lights, optical storage media and other light sources, light sources for electrophotographic copying machines, and light sources for optical communication processors. Examples include, but are not limited to, a light source of an optical sensor. In particular, it can be effectively used as a backlight of a liquid crystal display device and an illumination light source.

  In the organic EL element, patterning may be performed by a metal mask, an ink jet printing method, or the like as needed during film formation. In the case of patterning, only the transparent electrode and the counter electrode may be patterned, these electrodes and the light emitting layer may be patterned, or the entire element layer may be patterned. In manufacturing the element, a conventionally known method can be used.

(Lighting device)
The organic EL element used in the lighting device may be designed such that the organic EL element having the above-described configuration has a resonator structure. Examples of the purpose of use of the organic EL element configured as a resonator structure include, but are not limited to, a light source of an optical storage medium, a light source of an electrophotographic copying machine, a light source of an optical communication processor, a light source of an optical sensor, and the like. . Moreover, you may use for the said use by making a laser oscillation.

  Note that the material used for the organic EL element can be applied to an organic EL element that emits substantially white light (also referred to as a white organic EL element). For example, a plurality of light emitting materials can simultaneously emit a plurality of light emission colors to obtain white light emission by color mixing. The combination of a plurality of emission colors may include three emission maximum wavelengths of the three primary colors of red, green and blue, or two using the complementary colors such as blue and yellow, blue green and orange. The thing containing the light emission maximum wavelength may be used.

  In addition, the combination of luminescent materials for obtaining multiple luminescent colors is a combination of multiple phosphorescent or fluorescent materials that emit light, fluorescent materials or phosphorescent materials, and light from the luminescent materials. Any combination with a pigment material that emits light as light may be used, but in a white organic EL element, a combination of a plurality of light-emitting dopants may be used.

  Such a white organic EL element is different from a configuration in which organic EL elements each emitting light are individually arranged in parallel in an array to obtain white light emission, and the organic EL element itself emits white light. For this reason, a mask is not required for film formation of most layers constituting the element, and for example, an electrode film can be formed on one side by vapor deposition, casting, spin coating, ink jet, printing, etc., and productivity is improved. To do.

  In addition, the light emitting material used for the light emitting layer of such a white organic EL element is not particularly limited. For example, in the case of a backlight in a liquid crystal display element, the light emitting material is adapted to a wavelength range corresponding to CF (color filter) characteristics. Any one of the metal complexes according to the present invention and known light-emitting materials may be selected and combined for whitening.

  If the white organic EL element demonstrated above is used, it is possible to produce the illuminating device which produces substantially white light emission.

  The lighting device can also be used as a lighting device having a large light emitting surface by using, for example, a plurality of organic EL elements. In this case, the light emitting surface is enlarged by arranging a plurality of light emitting panels provided with organic EL elements on the support substrate (that is, tiling). The support substrate may also serve as a sealing member, and each light emitting panel is tiled in a state where the organic EL element is sandwiched between the support substrate and the transparent substrate of the light emitting panel. An adhesive may be filled between the support substrate and the transparent substrate, thereby sealing the organic EL element. Note that the terminals of the transparent electrode and the counter electrode are exposed around the light emitting panel.

  In the lighting device having such a configuration, the center of each light emitting panel is a light emitting region, and a non-light emitting region is generated between the light emitting panels. For this reason, a light extraction member for increasing the amount of light extracted from the non-light emitting area may be provided in the non-light emitting area of the light extraction surface. As the light extraction member, a light collecting sheet or a light diffusion sheet can be used.

<Effect>
The organic EL element 40 described above uses a transparent electrode 10 having a thin but uniform thickness and high surface smoothness metal layer 2 as an anode or a cathode, and a light emitting functional layer on the metal layer 2 of the transparent electrode 10. 3 and the counter electrode 5 are provided in this order. For this reason, the reduction of the rectification ratio and the occurrence of leakage due to insufficient smoothness of the electrode surface of the transparent electrode 10 are suppressed, and it is possible to improve the yield and the reliability.

  In addition, when a sufficient voltage is applied between the transparent electrode 10 and the counter electrode 5, the transparent electrode 10 has sufficient conductivity and transparency, so that the emitted light h from the transparent substrate 11 side. The light extraction efficiency can be improved, and the light emission efficiency can be improved. Further, since the transparent electrode 10 has a smooth electrode surface, light loss due to plasmon absorption can be suppressed on the electrode surface, and therefore, the luminous efficiency can be further improved.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to a following example.

<< Production of bottom emission type organic EL elements >>
Each organic EL element of Samples 101 to 136 was fabricated such that the area of the light emitting region was 5 cm × 5 cm. Table 2 below shows the configuration of each layer in each of the organic EL elements of Samples 101 to 136. The manufacturing procedure will be described with reference to FIG. 6 and Table 2 below.

<Procedure of Sample 101>
In the preparation of the sample 101, first, a conductive layer made of an ITO film is formed on the transparent substrate 11 (hereinafter referred to as the PET substrate 11) made of polyethylene terephthalate (PET) instead of the illustrated laminate 70 ′, and the transparent electrode 70 was produced. And after forming the light emission functional layer 3 and the counter electrode 5 on this transparent electrode 70, it solid-sealed with the sealing member, and the organic EL element 60 of the sample 101 was produced.

[Preparation of transparent electrode 70]
First, an ITO film having a film thickness of 150 nm was formed on the PET substrate 11 by sputtering. Thereby, a conductive layer made of an ITO film was produced, and a transparent electrode 70 composed of the PET substrate 11 and the conductive layer was formed.

[Preparation of Light-Emitting Functional Layer 3]
In the vacuum layer of the vacuum evaporation apparatus, the light emitting functional layer 3 was formed as follows.

(Hole transport / injection layer 31)
A hole transport / injection layer that serves both as a hole injection layer and a hole transport layer made of α-NPD, heated by energizing a heating boat containing α-NPD represented by the following structural formula as a hole transport injection material 31 was formed on the transparent electrode 70. At this time, the deposition rate was 0.1 nm / second to 0.2 nm / second, and the film thickness was 20 nm.

(Light emitting layer 32)
Next, the heating boat containing the host material H4 represented by the following structural formula and the heating boat containing the phosphorescent compound Ir-4 represented by the following structural formula were respectively energized independently, so that the host material H4 and the phosphorescent light emission were emitted. The light emitting layer 32 made of the photosensitive compound Ir-4 was formed on the hole transport / injection layer 31. At this time, the energization of the heating boat was adjusted so that the deposition rate was the host material H4: phosphorescent compound Ir-4 = 100: 6. The film thickness was 30 nm.

(Hole blocking layer 33)
Next, a heating boat containing BAlq represented by the following structural formula as a hole blocking material was energized and heated to form a hole blocking layer 33 made of BAlq on the light emitting layer 32. At this time, the deposition rate was 0.1 nm / second to 0.2 nm / second, and the film thickness was 10 nm.

(Electron transport / injection layer 34)
Thereafter, as an electron transport material, a heating boat containing a nitrogen-containing compound 10 having a structural formula as the nitrogen-containing compound (3) constituting the organic layer, and a heating boat containing potassium fluoride are independently provided. Then, an electron transport / injection layer 34 serving as both an electron injection layer and an electron transport layer made of the nitrogen-containing compound 10 and potassium fluoride was formed on the hole blocking layer 33. At this time, the energization of the heating boat was adjusted so that the deposition rate was nitrogen-containing compound 10: potassium fluoride = 75: 25. The film thickness was 30 nm.

[Preparation of counter electrode 5]
Next, the PET substrate 11 having the light emitting functional layer 3 formed in another vacuum layer is transferred, the pressure in the vacuum chamber is reduced to 4 × 10 ⁻⁴ Pa, and then heating with aluminum attached in the vacuum chamber is performed. The boat was energized and heated. Then, the counter electrode 5 made of aluminum having a film thickness of 100 nm was formed at a deposition rate of 0.3 nm / second. The counter electrode 5 is used as a cathode (cathode).

(Element sealing)
Thereafter, although not shown, the organic EL element 60 is covered with a sealing material made of a glass substrate having a thickness of 300 μm, and the adhesive is interposed between the sealing material and the PET substrate 11 so as to surround the organic EL element 60. (Sealing material) was filled. As the adhesive, an epoxy photocurable adhesive (Luxtrac LC0629B manufactured by Toagosei Co., Ltd.) was used. The adhesive filled between the sealing material and the PET substrate 11 was irradiated with UV light from the side of the sealing material made of a glass substrate, and the adhesive was cured to seal the organic EL element 60.

In the formation of the organic EL element 60, a vapor deposition mask is used for forming each layer, the central 4.5 cm × 4.5 cm of the 5 cm × 5 cm PET substrate is used as the light emitting region, and the width of the entire circumference of the light emitting region is 0. A non-light emitting region B of 25 cm is provided. In addition, the transparent electrode 70 serving as an anode (anode) and the counter electrode 5 serving as a cathode (cathode) are insulated from each other by the hole transport / injection layer 31 to the electron transport / injection layer 34. The terminal part was formed in the shape pulled out to the periphery.
Through the above steps, the organic EL element 60 of Sample 101 was produced.

<Procedure for Sample 102>
The organic EL element 60 of the sample 102 was produced in the same procedure as the sample 101 except that the metal layer made of silver (Ag) was used as a single layer instead of the laminate 70 ′. However, the film thickness of the metal layer made of silver (Ag) was 10 nm.

[Preparation of metal layer of transparent electrode 70]

  At this time, the metal layer made of silver (Ag) is formed by first fixing the PET substrate 11 to a substrate holder of a commercially available vacuum deposition apparatus, putting silver (Ag) in a resistance heating boat made of tungsten, and vacuum deposition apparatus. In a vacuum chamber.

Next, after depressurizing the vacuum tank to 4 × 10 ⁻⁴ Pa, the heating boat containing silver was energized and heated. Thereby, a metal layer made of silver having a film thickness of 10 nm was formed at a deposition rate of 0.1 nm / second to 0.2 nm / second. The production of the metal layer is the same below.

<Procedure of Sample 103>
In the procedure described in the preparation of the sample 102, the organic EL element 60 of the sample 103 is the same as the sample 102 except that an organic layer is formed by a vapor deposition method before the metal layer of the transparent electrode 70 is formed. Was made. That is, the laminate 70 ′ was formed by laminating an organic layer and a metal layer in this order.

[Preparation of Organic Layer of Transparent Electrode 70]
First, the PET substrate 11 was fixed to a substrate holder of a commercially available vacuum deposition apparatus. Further, Alq ₃ containing nitrogen represented by the following structural formula was put in a resistance heating boat made of tantalum. These substrate holders and resistance heating boats were attached to a vacuum chamber of a vacuum deposition apparatus. Alq ₃ used here is a compound containing nitrogen but having an effective unshared electron pair content [n / M] value of [n / M] <2.0 × 10 ^−3. .

Next, after depressurizing the vacuum chamber to 4 × 10 ⁻⁴ Pa, the heating boat containing Alq ₃ was energized and heated, and deposited on the PET substrate 11 at a deposition rate of 0.1 nm / sec to 0.2 nm / sec. An organic layer made of Alq _{3 having a} thickness of 10 nm was formed. The production of the organic layer is the same below.

<Procedure of Sample 104>
Compound No. 1 showed the structural formula using the organic layer as the nitrogen-containing compound (1). The organic EL element of the sample 104 was produced in the same procedure as the sample 103 except that it was configured as 7. Compound No. 7 is a compound having an effective unshared electron pair content [n / M] shown in Table 1 of 2.0 × 10 −3 ≦ [n / M].

<Procedure for Sample 105>
In the procedure described in the preparation of the sample 101, an organic EL element of the sample 105 was manufactured in the same procedure as the sample 101 except that a step of forming a scattering layer was added before the formation of the conductive layer. That is, the multilayer body 70 ′ was formed by laminating the scattering layer and the conductive layer in this order.

[Preparation of scattering layer of transparent electrode 70]
The dispersion liquid constituting the scattering layer is spin-coated on the PET substrate 11 by spin coating (500 rpm, 30 seconds), then simply dried (80 ° C., 2 minutes), and further baked (120 ° C., 60 minutes). Thus, a scattering layer having a thickness of 700 nm was formed. The production of the scattering layer is the same below.

(Production method of dispersion)
The dispersion was prepared as a scattering layer preparation, TiO ₂ particles (JR600A manufactured by Teika Co., Ltd.) having a refractive index of 2.4 and an average particle size of 0.25 μm, and a resin solution (ED230AL (organic / inorganic hybrid resin) manufactured by APM) and The formulation was designed at a ratio of 10 ml so that the solid content ratio of the solution was 70 vol% / 30 vol%, the solvent ratio of n-propyl acetate and cyclohexanone was 10 wt% / 90 wt%, and the solid content concentration was 15 wt%.

Specifically, the above-mentioned TiO ₂ particles and a solvent are mixed, and while cooling at room temperature, an ultrasonic disperser (UH-50 manufactured by SMT Co.) is used as a standard for a microchip step (MS-3 manufactured by SMT Co., Ltd.). Dispersion was added for 10 minutes under the conditions to prepare a TiO ₂ dispersion.
Next, while stirring the TiO ₂ dispersion at 100 rpm, the resin was mixed and added little by little. After the addition was completed, the stirring speed was increased to 500 rpm and mixed for 10 minutes to obtain a scattering layer coating solution.
Then, it filtered with the hydrophobic PVDF 0.45 micrometer filter (made by Whatman), and obtained the target dispersion liquid.

<Production Procedure of Sample 106>
In the procedure described in the preparation of the sample 102, the organic EL element 60 of the sample 106 is formed in the same procedure as the sample 102 except that a step of forming a scattering layer is added before the formation of the metal layer of the transparent electrode 70. Produced. That is, the laminate 70 ′ was formed by laminating the scattering layer and the metal layer in this order.

<Production Procedure of Samples 107 and 108>
In the procedure described in the preparation of the samples 103 and 104, the organic EL element of the samples 107 and 108 is the same as the sample 103 and 104 except that a step of forming a scattering layer is added before the formation of the organic layer. 60 was produced. That is, the laminate 70 ′ was formed by laminating a scattering layer, an organic layer, and a metal layer in this order.

<Procedure for Sample 109>
In the procedure described in the preparation of the sample 102, a procedure similar to that of the sample 102 is performed except that the formation of a compound layer composed of calcium carbonate (CaCO ₃ ) is added before the metal layer of the transparent electrode 70 is formed. An organic EL element 60 of Sample 109 was produced. That is, the laminated body 70 ′ was formed by laminating a compound layer and a metal layer in this order.

[Preparation of compound layer of transparent electrode 70]
First, the PET substrate 11 was fixed to a substrate holder of a commercially available vacuum deposition apparatus. Further, calcium carbonate (CaCO ₃ ) constituting the compound layer was placed in a resistance heating boat made of tantalum. These substrate holders and resistance heating boats were attached to a vacuum chamber of a vacuum deposition apparatus.

Next, after depressurizing the vacuum tank to 4 × 10 ⁻⁴ Pa, it is heated by energizing a heating boat containing calcium carbonate (CaCO ₃ ), and transparent at a deposition rate of 0.1 nm / second to 0.2 nm / second. A compound layer made of calcium carbonate (CaCO ₃ ) having a thickness of 3 nm was formed on the substrate 11. The production of the compound layer is the same below.

<Procedure for Sample 110-114>
In the procedure described in the preparation of the sample 109, the steps of the samples 110 to 114 are the same as those of the sample 109 except that a step of forming an organic layer with each material shown in Table 2 below is added before the formation of the compound layer. The organic EL element 60 was produced. That is, the laminate 70 ′ was formed by laminating an organic layer, a compound layer, and a metal layer in this order.

<Procedure of Sample 115>
In the procedure described in the preparation of the sample 109, the organic EL element 60 of the sample 115 was manufactured in the same procedure as the sample 109 except that a step of forming a scattering layer was added before the formation of the compound layer. That is, the laminate 70 ′ was formed by laminating a scattering layer, a compound layer, and a metal layer in this order.

<Procedure for Producing Samples 116-120>
In the procedure described in the preparation of samples 110 to 114, the organic EL elements of samples 116 to 120 are the same as the samples 110 to 114 except that a step of forming a scattering layer is added before the formation of the organic layer. 60 was produced. That is, the laminate 70 ′ was formed by laminating a scattering layer, an organic layer, a compound layer, and a metal layer in this order.

<Production Procedure of Samples 121 and 122>
Samples 121 and 122 of organic EL elements 60 were fabricated in the same procedure as Sample 116, except that the organic layer was composed of the materials shown in Table 2 below.

<Procedures for Samples 123 to 134>
Organic EL elements 60 of Samples 123 to 134 were produced in the same procedure as Sample 120 except that the compound layer was composed of each material shown in Table 2 below.

<Production Procedure of Samples 135 and 136>
The organic EL elements of Samples 135 and 136 are the same as Samples 114 and 120 except that the counter electrode 5 is composed of a compound layer composed of calcium carbonate (CaCO ₃ ) and a metal layer composed of Ag. Was made. However, the thickness of the metal layer of the counter electrode 5 was 100 nm, and the counter electrode 5 was formed by laminating a compound layer and a metal layer on the light emitting functional layer 3 in this order.

[Preparation of counter electrode 5]
The PET substrate 11 on which the light emitting functional layer 3 is formed is transferred into another vacuum chamber, the pressure inside the vacuum chamber is reduced to 4 × 10 ⁻⁴ Pa, and then the heating boat containing calcium carbonate (CaCO ₃ ) is energized. And heated. Then, a compound layer made of calcium carbonate (CaCO ₃ ) having a film thickness of 3 nm was formed on the transparent substrate 11 at a deposition rate of 0.1 nm / second to 0.2 nm / second.

Subsequently, the PET substrate 11 on which the compound layer of the counter electrode was formed was transferred to another vacuum chamber while maintaining a vacuum, and after the vacuum layer was depressurized to 4 × 10 ⁻⁴ Pa, a heated boat containing silver Was energized and heated. Thereby, a metal layer made of silver having a film thickness of 100 nm was formed at a deposition rate of 0.1 nm / second to 0.2 nm / second, and the counter electrode 5 composed of the compound layer and the metal layer was formed.

<Evaluation of Samples in Examples>
About each organic EL element of the samples 101-136 produced above, (1) power efficiency, (2) rectification ratio, and (3) high temperature and high humidity preservation property were measured.

(1) The power efficiency is measured using the spectral radiance meter CS-2000 (manufactured by Konica Minolta) to measure the front luminance of the organic EL elements of Samples 101 to 136 and evaluate the power efficiency at a front luminance of 1000 cd / m ² . did. Note that the power efficiency was evaluated as a relative value with the power efficiency of the sample 101 as 100.
(2) The rectification ratio is determined by measuring the forward voltage flowing through each organic EL element at 500 μA / cm ² at room temperature and the current value due to the reverse voltage three times, calculating the rectification ratio from the average value, and calculating the logarithm value. The value taken by (Log) is shown. The higher the rectification ratio, the better the leak characteristics. The results are also shown in Table 2 below.
(3) The high temperature and high humidity storage stability is such that 10 organic EL elements sealed as in the samples 101 to 136 are prepared, and the number of emitted light after storing them in a high temperature and high humidity environment ( n / 10). The high temperature and high humidity environment was a temperature of 60 ° C., a humidity of 90%, and a storage time of 300 hours. During storage, each light emitting element was driven with a driving voltage at which the luminance was 1000 cd. The number of luminescence (n / 10) is the number of luminescence confirmed after 300 hours of storage among 10 samples 101 to 136, and the closer to 10, the more preferable.

<Evaluation results of examples>
As is clear from Table 2, each of the organic EL elements of Samples 109 to 136 provided with the transparent electrode having the compound layer has power efficiency compared to each of the organic EL elements of Samples 101 to 108 having no compound layer. The rectification ratio was high and the high temperature / high humidity storage value was good.

  Therefore, it was confirmed that by providing the compound layer, it is possible to suppress a decrease in the rectification ratio in the element of the organic EL element, occurrence of leakage, and the like, and to improve the yield as well as the reliability. That is, it was confirmed that the conductivity and light transmittance of the transparent electrode can be improved.

  In addition, among the organic EL elements of samples 109 to 120, the organic layers are the same for each of the organic EL elements of samples 115 to 120 provided with the scattering layer and each of the organic EL elements of samples 109 to 114 having no scattering layer. Comparing materials composed of materials, it was confirmed that each of the organic EL elements of Samples 115 to 120 provided with the scattering layer had a lower rectification ratio but improved power efficiency.

  Therefore, it was confirmed that the light extraction efficiency of the organic EL element can be improved by providing the scattering layer. Moreover, in the transparent electrode, it was confirmed that the light transmittance to the transparent substrate side of the transparent electrode can be improved.

  In addition, among the organic EL elements of samples 109 to 120, each of the organic EL elements of samples 110 to 114 and 116 to 120 provided with an organic layer is different from each of the organic EL elements of samples 109 and 115 having no organic layer. Compared with each other, improvement in power efficiency was confirmed.

Furthermore, among the organic EL elements of Samples 110 to 114 and 116 to 122 having different materials constituting the organic layer, the effective unshared electron pair content [n / M] is 2.0 × 10 ⁻³ ≦ [n / M] samples 111 to 114 having organic layers composed of nitrogen-containing compounds (1) and 117 to 122 each of which has an organic layer composed of materials outside this range. Compared with each of the organic EL elements 110 and 116, better results were obtained in both power efficiency and rectification ratio.

Here, FIG. 7 shows the material No. 1 in which the effective unshared electron pair content [n / M] is 2.0 × 10 ⁻³ ≦ [n / M] ≦ 1.9 × 10 ^−2. In the case where a metal layer made of silver (Ag) having a film thickness of 6 nm is formed on the top of the organic layer using No. 20, the effective unshared electron pair content [n / M] of the compound constituting the organic layer is The graph which plotted the value of the sheet resistance measured about the metal layer is shown.

From the graph of FIG. 7, when the effective unshared electron pair content [n / M] is in the range of 2.0 × 10 ⁻³ ≦ [n / M] ≦ 1.9 × 10 ⁻² , the effective unshared electron pair content is included. As the value of the rate [n / M] is larger, the sheet resistance of the metal layer tends to be lower. If the effective unshared electron pair content [n / M] = 3.9 × 10 ⁻³ is a boundary and the range is 3.9 × 10 ⁻³ ≦ [n / M], the sheet resistance is dramatically increased. It was confirmed that the effect of lowering was obtained.

  In addition, in each of the organic EL elements of Samples 123 to 134 having different materials constituting the compound layer, the same good results were obtained.

  In addition, among the organic EL elements of the samples 114, 120, 135, and 136 having different layer configurations of the counter electrode, the organic EL elements of the samples 135 and 136 having the counter electrode configured by the compound layer and the metal layer are Improvement in power efficiency was confirmed.

  Therefore, it was confirmed that the counter electrode composed of the compound layer and the metal layer can improve the reflectance to the transparent substrate side.

  From the above, it was confirmed that the organic EL device using the transparent electrode of the present invention has improved power efficiency, rectification ratio, and high temperature / high humidity storage stability.

DESCRIPTION OF SYMBOLS 10, 20, 30, 70 ... Transparent electrode, 10 ', 20', 30 ', 70' ... Laminated body, 40, 50, 60 ... Organic EL element, 1a ... Compound layer, 1b ... Organic layer, 1c ... Scattering layer DESCRIPTION OF SYMBOLS 2 ... Metal layer, 3 ... Light emitting functional layer, 5, 7 ... Counter electrode, 11 ... Transparent substrate, 11a ... Light extraction surface, 31 ... Hole transport / injection layer, 3a, 32 ... Light emitting layer, 33 ... Hole Blocking layer 34 ... Electron transport / injection layer

Claims (21)

A transparent substrate;
A compound layer comprising an alkali metal or an alkaline earth metal and oxygen, and provided on one main surface side of the transparent substrate;
A transparent electrode having a metal layer made of silver or an alloy containing silver as a main component and provided on one main surface side of the transparent substrate via the compound layer. The transparent electrode according to claim 1, wherein the transparent electrode is configured using a compound having a Lewis base, and has an organic layer sandwiched between the transparent substrate and the compound layer. The organic layer is composed of a compound containing at least one of a nitrogen atom (N) and a sulfur atom (S),
The compound includes the number of unshared electron pairs that are not involved in aromaticity and are not coordinated to metal among the unshared electron pairs of the nitrogen atom (N) and sulfur atom (S) contained in the compound. The transparent electrode according to claim 2, wherein the effective unshared electron pair content [n / M] is 2.0 × 10 ⁻³ ≦ [n / M] when n and the molecular weight are M. 4. The effective unshared electron pair content [n / M] in the compound is 3.9 × 10 ⁻³ ≦ [
n / M]. The transparent electrode according to claim 3. The transparent electrode according to any one of claims 2 to 4, wherein the organic layer contains a compound represented by the following general formula (1).

[However, in the general formula (1),
X11 represents -N (R11)-or -O-,
E101 to E108 each represent -C (R12) = or -N =, and at least one of E101 to E108 is -N =,
R11 and R12 each represent a hydrogen atom (H) or a substituent. ] The transparent electrode according to claim 5, wherein the organic layer contains a compound represented by the following general formula (1a) in which X11 in the general formula (1) is -N (R11)-.

The transparent electrode according to claim 6, wherein the organic layer contains a compound represented by the following general formula (1a-1) in which E104 in the general formula (1a) is −N =.

The transparent electrode according to claim 6, wherein the organic layer contains a compound represented by the following general formula (1a-2) in which E103 and E106 in the general formula (1a) are -N =.

The transparent electrode according to claim 5, wherein the organic layer contains a compound represented by the following general formula (1b) in which X11 in the general formula (1) is -O- and E104 is -N =.

The said organic layer contains the compound represented by following General formula (2). The transparent electrode as described in any one of Claims 2-4.

[However, in general formula (2),
Y21 represents a divalent linking group composed of an arylene group, a heteroarylene group, or a combination thereof;
E201 to E216 and E221 to E238 each represent -C (R21) = or -N =
R21 represents a hydrogen atom (H) or a substituent,
At least one of E221 to E229 and at least one of E230 to E238 is -N =;
k21 and k22 represent an integer of 0 to 4, but k21 + k22 is an integer of 2 or more. ] The said organic layer contains the compound represented by following General formula (3). The transparent electrode as described in any one of Claims 2-4.

[However, in general formula (3),
E301 to E312 each represent -C (R31) =
R31 represents a hydrogen atom (H) or a substituent,
Y31 represents a divalent linking group composed of an arylene group, a heteroarylene group, or a combination thereof. ] The transparent electrode according to any one of claims 2 to 4, wherein the organic layer contains a compound represented by the following general formula (4).

[However, in general formula (4),
E401 to E414 each represent -C (R41) =
R41 represents a hydrogen atom (H) or a substituent,
Ar41 represents a substituted or unsubstituted aromatic hydrocarbon ring or aromatic heterocyclic ring;
k41 represents an integer of 3 or more. ] The transparent electrode according to claim 2, wherein the organic layer contains a compound represented by the following general formula (5).

[However, in general formula (5),
R51 represents a substituent,
E501, E502, E511 to E515, E521 to E525 each represent -C (R52) = or -N =
E503 to E505 each represent -C (R52) =
R52 represents a hydrogen atom (H) or a substituent,
At least one of E501 and E502 is -N =;
At least one of E511 to E515 is -N =;
At least one of E521 to E525 is -N =. ] The said organic layer contains the compound represented by following General formula (6). The transparent electrode as described in any one of Claims 2-4.

[However, in general formula (6),
E601 to E612 each represent -C (R61) = or -N =
R61 represents a hydrogen atom (H) or a substituent;
Ar61 represents a substituted or unsubstituted aromatic hydrocarbon ring or aromatic heterocyclic ring. ] The transparent electrode according to any one of claims 2 to 4, wherein the organic layer contains a compound represented by the following general formula (7).

[However, in general formula (7),
R71 to R73 each represents a hydrogen atom (H) or a substituent,
Ar71 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group. ] The transparent electrode according to claim 2, wherein the organic layer contains a compound represented by the following general formula (8).

[However, in general formula (8),
R81 to R86 each represent a hydrogen atom (H) or a substituent,
E801 to E803 each represent -C (R87) = or -N =
R87 represents a hydrogen atom (H) or a substituent,
Ar81 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group. ] The transparent electrode according to claim 16, wherein the organic layer contains a compound represented by the following general formula (8a).

[However, in the general formula (8a)
E804 to E811 each represent -C (R88) = or -N =
Each R88 represents a hydrogen atom (H) or a substituent;
At least one of E808 to E811 is -N =;
E804 to E807 and E808 to E811 may be bonded to each other to form a new ring. ] The transparent electrode as described in any one of Claims 1-17 which has a scattering layer provided adjacent to the one main surface side of the said transparent substrate. The organic electroluminescent element which has a transparent electrode in any one of Claims 1-18. The organic electroluminescent element according to claim 19, having a configuration in which a light emitting functional layer and a counter electrode are laminated in this order on a metal layer of the transparent electrode. The counter electrode includes a compound layer configured to contain an alkali metal or an alkaline earth metal and oxygen from the light emitting functional layer side,
The organic electroluminescence device according to claim 20, wherein the organic electroluminescence device has a configuration in which a metal layer composed of silver or an alloy containing silver as a main component is laminated in this order.

Images