JP2005085731A - ORGANIC ELECTROLUMINESCENT DEVICE, METHOD FOR PRODUCING ORGANIC ELECTROLUMINESCENT DEVICE, AND ELECTRONIC DEVICE - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electroluminescent device, a method for manufacturing an organic electroluminescent device, and an electronic device that can reduce the number of steps and improve productivity.
An organic electroluminescence device including a light emitting functional layer 60 formed on electrodes 23 and 50, wherein the light emitting functional layer 60 includes a light emitting material and a material of a self-assembled monolayer SAM. The self-assembled film SAM is formed on the surface of at least one electrode 23.
[Selection] Figure 5

Description

  The present invention relates to an organic electroluminescence device, a method for manufacturing an organic electroluminescence device, and an electronic apparatus.

In recent years, development of an organic electroluminescence (hereinafter, abbreviated as “organic EL”) device using an organic substance has been accelerated as a spontaneous emission type display replacing a liquid crystal display. In such an organic EL device, a structure in which a hole injection / transport layer (hereinafter referred to as “hole transport layer”) and a light emitting layer are laminated between an anode and a cathode is generally known. ing.
In addition, in a method for manufacturing an organic EL device, a method has been proposed in which a polymer material is employed as a hole transport layer material and a light emitting layer material, and this is formed by a liquid phase method for each layer (for example, Patent Documents). 1).
JP 2003-142260 A

  However, the above-described prior art requires a process for forming each layer of the hole transport layer and the light emitting layer, and there is a problem in that the production efficiency is reduced due to an increase in processes.

  The present invention has been made to solve the above-described problem, and achieves reduction in the number of steps and enables improvement in productivity, an organic electroluminescence device manufacturing method, and an electronic device The purpose is to provide equipment.

In order to achieve the above object, the present invention employs the following configuration.
The organic EL device of the present invention is an organic electroluminescence device including a light emitting functional layer formed between electrodes, and the light emitting functional layer includes a light emitting material and a material of a self-assembled monolayer, The organized film is formed on the surface of at least one of the electrodes.
Here, as the material of the self-assembled monolayer, various known materials are adopted, and the surface of the anode or the cathode is obtained by contacting such a material with the anode or the cathode in a liquid phase state. A monomolecular film is formed in a self-assembled manner.
Further, such a self-assembled monomolecular film has a property of injecting / transporting holes suitably to the luminescent material when formed on the anode, for example, or is formed on the luminescent material when formed on the cathode. On the other hand, it has a property of injecting / transporting electrons suitably.
Therefore, the self-assembled monolayer material contained in the light emitting functional layer is formed on the surface of one electrode in a self-assembled manner. In addition, since the self-assembled monomolecular film has hole injection / transport properties or electron injection / transport properties, it is not necessary to form each of the hole transport layer and the light emitting layer in separate steps as in the conventional case. Since the light emitting functional layer can be formed by the process, the number of processes can be reduced and the productivity can be improved.
In the present invention, the “hole transport layer” also includes the meaning as “hole injection layer” having hole injection property, and the “electron transport layer” also has the meaning as “electron injection layer” having electron injection property. It will be described as including.

In the organic EL device, the self-assembled monolayer preferably has a molecular structure represented by X— (CH ₂ ) _n —Y.
Here, X means a group bonded to the electrode, and Y means a group arranged on the light emitting material side.
In addition, the group of X includes a silanol group (—Si (OH) ₃ ), a trichlorosilyl group (—SiCl ₃ ), a triethoxysilyl group (—Si (OEt) ₃ ), and a trimethoxysilyl group (—Si (OMe). ₃ ), thiol group (—SH), hydroxyl group (—OH), amino group (—NH ₂ ), phosphate group (—PO ₃ H ₂ ), carboxyl group (—COOH), sulfonic acid group (—SO) ₃ H), a phosphoric acid chloride group (—PO ₂ Cl ₂ ), a carboxylic acid chloride group (—COCl), and a sulfonic acid chloride group (—SO ₂ Cl).
The group of Y is a methyl group (CH ₃ ), a trifluoromethyl group (CF ₃ ), an aromatic functional group, a group consisting of a benzene derivative, a group consisting of a biphenyl derivative, a group consisting of a triarylamine derivative, and It preferably contains any one of groups consisting of phthalocyanine derivatives.

In this way, since a suitable self-assembled monolayer can be formed, the same effects as described above can be obtained.
Moreover, in such a self-assembled monolayer, it is preferable to select a group that binds to the electrode according to various electrode materials. For example, when the electrode material is a noble metal such as gold or silver, it is preferable to employ a self-assembled monolayer having a thiol group as a group that binds to the electrode, and the electrode material is made of glass. When the substrate has an oxide such as ITO, it is preferable to employ a self-assembled monolayer having a siloxane group as the group.
Moreover, it is preferable to employ an aromatic functional group (benzene nucleus) as the group disposed on the light emitting material side. In this case, since the benzene nucleus has an electron donating property, the functional group around the benzene nucleus is in an electron excess state, so that the lyophilicity can be enhanced.
The group disposed on the light emitting material side is preferably a functional group having hole injection / transport properties.

In the organic EL device, the number of n is preferably 0 to 10.
Regarding the length of the alkyl group, it has been reported that the self-assembled film has an insulating property as the number of n increases. Therefore, in the present invention, since the number of n is 0 to 10, it is possible to form a self-organized monomolecular film having conductivity, and the hole transport property and the electron transport property can be suitably obtained.

In addition, the organic EL device manufacturing method of the present invention is a method for manufacturing an organic electroluminescence device having a light emitting functional layer formed between electrodes, in which a light emitting material and a self-assembled monolayer material are mixed. The light emitting functional layer is formed by applying the mixed material applied to the surface of at least one of the electrodes.
In this way, the self-assembled monolayer material contained in the light emitting functional layer is formed on the surface of one of the electrodes in a self-organized manner. In addition, since the self-assembled monomolecular film has hole injection / transport properties or electron injection / transport properties, it is not necessary to form each of the hole transport layer and the light emitting layer in separate steps as in the conventional case. Since the light emitting functional layer can be formed by the process, the number of processes can be reduced and the productivity can be improved.

Moreover, in the manufacturing method of the said organic EL apparatus, it is preferable to apply | coat the said mixed material by using a liquid phase method.
Here, the liquid phase method is also called a wet process or a wet coating method, and is a method for bringing a substrate and a liquid material into contact with each other, and includes an ink jet (droplet discharge) method, a spin coating method, a slit coating method. It means a method, a dip coating method, a spray film forming method, a printing method, a liquid discharge method and the like. In addition, after performing a liquid phase method, it is common to perform the heat processing for drying and heating a liquid material.
The liquid phase method is a suitable method for forming a polymer material, and an organic EL device can be manufactured at low cost without using expensive equipment such as a vacuum device as compared with a gas phase method.

In the method for manufacturing the organic EL device, the liquid phase method is preferably a droplet discharge method.
The droplet discharge method is a color printing technique well known for so-called inkjet printers, which discharges material ink droplets made by liquefying various materials from an inkjet head onto a transparent substrate and fixes them. is there. According to the droplet discharge method, since the material ink droplets can be accurately discharged to a fine region, the material ink can be directly fixed to a desired colored region without performing photolithography. Accordingly, no material is wasted and the manufacturing cost can be reduced, which is a very rational method.
Therefore, the light emitting functional layer can be formed inexpensively and accurately by using the droplet discharge method.

In addition, an electronic apparatus according to the present invention includes the above-described organic EL device.
Thereby, an inexpensive electronic device can be provided.

The present invention will be described in detail below.
First, prior to describing the manufacturing method of the organic EL device of the present invention, the wiring structure of the organic EL device obtained by the manufacturing method of the present invention will be described with reference to FIG.
An organic EL device 1 shown in FIG. 1 is an active matrix type device using a thin film transistor (hereinafter abbreviated as TFT) as a switching element.

As shown in FIG. 1, the organic EL device 1 includes a plurality of scanning lines 101, a plurality of signal lines 102 extending in a direction perpendicular to the scanning lines 101, and parallel to each signal line 102. And a plurality of power supply lines 103 extending in parallel to each other, and pixel regions X are provided near intersections of the scanning lines 101 and the signal lines 102.
A data line driving circuit 100 including a shift register, a level shifter, a video line, and an analog switch is connected to the signal line 102. Further, a scanning line driving circuit 80 including a shift register and a level shifter is connected to the scanning line 101.

  Further, in each pixel region X, a switching TFT 112 to which a scanning signal is supplied to the gate electrode via the scanning line 101 and a storage capacitor for holding a pixel signal shared from the signal line 102 via the switching TFT 112. 113, a driving TFT 123 to which a pixel signal held by the holding capacitor 113 is supplied to the gate electrode, and a driving current from the power supply line 103 when electrically connected to the power supply line 103 via the driving TFT 123 And a functional layer 110 (corresponding to a light emitting functional layer and an electron transport layer in the following description) sandwiched between the pixel electrode 23 and the cathode 50 are provided.

  According to the organic EL device 1, when the scanning line 101 is driven and the switching TFT 112 is turned on, the potential of the signal line 102 at that time is held in the holding capacitor 113, and according to the state of the holding capacitor 113. The on / off state of the driving TFT 123 is determined. Then, a current flows from the power supply line 103 to the pixel electrode 23 via the channel of the driving TFT 123, and further a current flows to the cathode 50 via the functional layer 110. The functional layer 110 emits light according to the amount of current flowing through it.

Next, a specific configuration of the organic EL device 1 shown in FIG. 1 will be described with reference to FIGS.
As shown in FIG. 2, the organic EL device 1 includes a substrate 20 having light transparency and electrical insulation, and pixel electrodes connected to a switching TFT (not shown) arranged in a matrix on the substrate 20. A pixel electrode area (not shown), a power supply line (not shown) arranged around the pixel electrode area and connected to each pixel electrode, and at least a rectangular shape in plan view located on the pixel electrode area The pixel portion 3 (inside the one-dot chain line frame in FIG. 2). The pixel unit 3 includes a real display area 4 (inside the two-dot chain line in FIG. 2) in the center and a dummy area 5 (an area between the one-dot chain line and the two-dot chain line) arranged around the real display area 4. ) And is divided.

In the actual display area 4, display areas R, G, and B each having a pixel electrode are arranged apart from each other in the AB direction and the CD direction.
Further, scanning line driving circuits 80 and 80 are arranged on both sides of the actual display area 4 in FIG. These scanning line drive circuits 80 and 80 are arranged below the dummy region 5.

  Further, an inspection circuit 90 is arranged above the actual display area 4 in FIG. This inspection circuit 90 is a circuit for inspecting the operating state of the organic EL device 1 and includes, for example, inspection information output means (not shown) for outputting the inspection result to the outside, and is displayed during manufacture or at the time of shipment. The apparatus is configured to be able to inspect the quality and defect of the apparatus. The inspection circuit 90 is also disposed below the dummy area 5.

  The scanning line driving circuit 80 and the inspection circuit 90 are applied with a driving voltage from a predetermined power supply unit via the driving voltage conducting unit 310 (see FIG. 3) and the driving voltage conducting unit 340 (see FIG. 4). It is configured. The drive control signals and drive voltages to the scanning line drive circuit 80 and the inspection circuit 90 are supplied from a predetermined main driver that controls the operation of the organic EL device 1 and the drive control signal conduction unit 320 (see FIG. 3) and Transmission and application are performed via the drive voltage conduction unit 350 (see FIG. 4). The drive control signal in this case is a command signal from a main driver or the like related to control when the scanning line drive circuit 80 and the inspection circuit 90 output signals.

  As shown in FIGS. 3 and 4, the organic EL device 1 is formed by bonding a substrate 20 and a sealing substrate 30 through a sealing resin 40. In a region surrounded by the substrate 20, the sealing substrate 30, and the sealing resin 40, a desiccant 45 is attached to the inner surface of the sealing substrate 30. The space is filled with nitrogen gas to form a nitrogen gas filled layer 46. Under such a configuration, moisture and oxygen are prevented from penetrating into the organic EL device 1, thereby extending the lifetime of the organic EL device 1. A getter agent may be used in place of the desiccant 45.

In the case of a so-called top emission type organic EL device, the substrate 20 is configured to extract emitted light from the sealing substrate 30 side that is the opposite side of the substrate 20, so that both a transparent substrate and an opaque substrate can be used. it can. Examples of the opaque substrate include a thermosetting resin and a thermoplastic resin in addition to a ceramic sheet such as alumina and a metal sheet such as stainless steel that has been subjected to an insulation treatment such as surface oxidation.
Further, in the case of a so-called back emission type organic EL device, since the emitted light is extracted from the substrate 20 side, a transparent or semi-transparent substrate 20 is employed. For example, glass, quartz, resin (plastic, plastic film) and the like can be mentioned, and a glass substrate is particularly preferably used. In the present embodiment, a back emission type in which emitted light is extracted from the substrate 20 side is used. Therefore, a transparent or translucent substrate 20 is used.
As the sealing substrate 30, for example, a plate-like member having electrical insulation can be employed. Further, the sealing resin 40 is made of, for example, a thermosetting resin or an ultraviolet curable resin, and is preferably made of an epoxy resin which is a kind of thermosetting resin.

Further, a circuit unit 11 including a driving TFT 123 for driving the pixel electrode 23 and the like is formed on the substrate 20, and further functions as an anode on the circuit unit 11 as shown in FIG. The pixel electrode 23, a light emitting functional layer 60 having a hole injection / transport property and having a light emitting ability, an electron transport layer 65, and a cathode 50 are formed in this order.
In the present embodiment, a configuration in which the electron transport layer 65 is provided will be described. However, the electron transport layer 65 is not necessarily provided, and the presence or absence of the electron transport layer 65 is determined according to the form of the organic EL device 1. Is done.

  Further, as shown in FIG. 2, the organic EL device 1 of the present invention has dots that emit red (R), green (G), and blue (B) in its actual display region 4, thereby providing full color display. It is what constitutes. As shown in an enlarged view in FIG. 5, an electron transport layer 65 for injecting / transporting electrons from the cathode 50 is formed between the light emitting functional layer 60 and the cathode 50. , Blue (B), red (R), and green (G), the material structure is selected.

  Under such a configuration, the holes supplied from the pixel electrode 23 and the electrons supplied from the cathode 50 are combined in the light emitting functional layer 60 to generate light emission.

The pixel electrode 23 that functions as an anode is a back-emission type in this example, and thus is formed of a transparent conductive material. ITO is suitable as the transparent conductive material. In addition, for example, an indium oxide / zinc oxide amorphous transparent conductive film (Indium Zinc Oxide: IZO / registered trademark)) (Idemitsu Kosan) Etc.) can be used. In the present embodiment, ITO is used, but Pt, Ir, Ni, Pd, or the like can be used instead.
About the film thickness of the pixel electrode 23, it is preferable to set it as 50-200 nm, and it is especially preferable to set it as about 150 nm.

  The material for forming the electron transport layer 65 is made of an alkali metal, alkaline earth metal, or rare earth metal halide or oxide. For example, Li, Na, and Cs are used as the alkali metal, and Ca, Ba, and Sr are used as the alkaline earth metal, and Sm, Tb, and Er are used as the rare earth metal. These metals are particularly preferably used and formed as fluorides, but may be other halides, that is, chlorides or bromides, or oxides.

  The film thickness of the electron transport layer 65 formed from such a compound is preferably 0.5 to 10 nm, and particularly preferably an extremely thin film of 5 nm or less. In addition, the formation of such an electron transport layer 5 is performed by a droplet discharge method such as an ink jet method as will be described later. When the dispersion liquid is applied, a thin film on the order of several nm can be formed. This is preferable. As a dispersion medium used for dispersion of the ultrafine particles, it is preferable to use a polar solvent such as water, methanol, ethanol, propanol, isopropyl alcohol (IPA), or dimethyl ketone because the light emitting functional layer 60 is not redissolved.

As shown in FIGS. 3 to 5, the cathode 50 has an area larger than the total area of the actual display region 4 and the dummy region 5 and is formed so as to cover each.
As a material for forming the cathode 50, it is desirable to form a material having a small work function on the light emitting functional layer 60 side (lower side), and for example, Ca, Ba, or the like is used. In addition, a material having a work function higher than that of the light emitting functional layer 60 side, for example, Al is used on the upper side (sealing side). About the film thickness of the cathode 50, it is preferable to set it as 100-1000 nm, and it is preferable to set it especially as about 200-500 nm. Since the present embodiment is a back emission type, the cathode 50 does not have to be particularly light transmissive.

As a material for forming the light emitting functional layer 60, a mixture of a light emitting material and a material for forming a self-assembled monolayer is used.
As the light emitting material, a known light emitting material capable of emitting fluorescence or phosphorescence can be used. Specifically, (poly) paraphenylene vinylene derivatives, polyphenylene derivatives, polyfluorene derivatives, polyvinyl carbazole, polythiophene derivatives, perylene dyes, coumarin dyes, rhodamine dyes, or polymer materials such as rubrene, perylene, 9, 10-diphenylanthracene, tetraphenylbutadiene, Nile red, coumarin 6, quinacridone, and the like can also be used.

  As the solvent for liquefying the material of the light emitting functional layer 60, a polar solvent or a nonpolar solvent is used. In particular, when the light emitting functional layer forming material is applied by an inkjet method (droplet discharge method) or the like as described later, water, isopropyl alcohol (IPA), normal butanol, γ-butyrolactone, N-methyl are used as polar solvents. Pyrrolidone (NMP), 1,3-dimethyl-2-imidazolidinone (DMI) and derivatives thereof, and glycol ethers such as carbitol acetate and butyl carbitol acetate can also be used. Further, it is preferable to use dihydrobenzofuran, trimethylbenzene, tetramethylbenzene, cyclohexylbenzene, or a mixture thereof as the nonpolar solvent. In addition, when applying by spin coating or dip, toluene, xylene or the like is preferably used.

The material of the self-assembled monomolecular film is used by being mixed with the light emitting material and the solvent described above, and by discharging (coating) the liquid mixture onto the pixel electrode 23 by an inkjet method or the like, the pixel electrode A monomolecular film is formed on the surface 23.
The schematic diagram of the self-assembled monolayer will be described with reference to FIG. 6. When the inkjet method is used, as shown in FIG. When the mixed liquid LQ with the material of the molecular film SAM is discharged to the pixel electrode 23, a self-assembled monomolecular film SAM is formed on the surface of the pixel electrode 23 as shown in FIG. Here, when the partial enlarged view T of the self-assembled monolayer SAM is shown in FIG. 6 (c), the self-assembled monolayer SAM is arranged on the side of the light emitting material EM and the group (X) bonded to the electrode. Group (Y) and a linear molecule.

Next, the main part of FIG. 5 will be described.
FIG. 7 is a view showing the pixel electrode 23, the light emitting functional layer 60, the electron transport layer 65, and the cathode 50 in FIG.
In the light emitting functional layer 60 shown in FIG. 7, the self-assembled monolayer SAM is disposed on the surface of the pixel electrode 23 by discharging the mixed liquid LQ as shown in FIGS. 6 (a) and 6 (b). Furthermore, by performing a heat treatment such as a drying process, the self-assembled monolayer SAM and the light emitting material EM are formed on the pixel electrode 23. Further, the organic EL device 1 is configured by stacking the electron transport layer 65 and the cathode 50 above the light emitting functional layer 60.
This self-assembled monomolecular film SAM has a property of injecting / transporting holes to the light emitting material EM of the light emitting functional layer 60 by being formed on the surface of the pixel electrode 23, so-called hole transport layer. Function as.

Next, the molecular structure of the self-assembled monolayer SAM will be described in detail.
The molecular configuration of the self-assembled monolayer in the present invention is represented by X— (CH ₂ ) _n —Y. Here, X represents a group bonded to the electrode, Y represents a group disposed on the light emitting material side, and (CH ₂ ) _n represents a linear molecule.

Examples of the group X bonded to the electrode include a silanol group (—Si (OH) ₃ ), a trichlorosilyl group (—SiCl ₃ ), a triethoxysilyl group (—Si (OEt) ₃ ), and a trimethoxysilyl group (— Si (OMe) ₃ ), thiol group (—SH), hydroxyl group (—OH), amino group (—NH ₂ ), phosphate group (—PO ₃ H ₂ ), carboxyl group (—COOH), sulfonic acid group It preferably consists of any one of (—SO ₃ H), phosphoric acid chloride group (—PO ₂ Cl ₂ ), carboxylic acid chloride group (—COCl), and sulfonic acid chloride group (—SO ₂ Cl).
Such a group X is appropriately selected according to the type of the pixel electrode material. For example, when the pixel electrode material is ITO as shown in this embodiment, it is preferable to select a self-assembled monolayer SAM that forms a siloxane bond.
When the electrode material is a noble metal such as gold or silver, it is preferable to employ a self-assembled monolayer having a thiol group as a group that binds to the electrode.

In addition, as the group Y arranged on the light emitting material EM side, a methyl group (CH ₃ ), a trifluoromethyl group (CF ₃ ), an aromatic functional group, a group composed of a benzene derivative, a group composed of a biphenyl derivative, a triaryl It preferably consists of either a group consisting of an amine derivative or a group consisting of a phthalocyanine derivative.
Further, when an aromatic functional group (benzene nucleus) is adopted as such a group Y, the benzene nucleus has an electron donating property, so that the functional group around the benzene nucleus is in an electron excess state. And lyophilicity can be enhanced.
The group Y is preferably a functional group having hole injection / transport properties.

The number of n in the straight-chain molecule _{(CH 2) n} is preferably 0-10. By defining the number of n in this way, it is possible to form a self-assembled monolayer SAM having conductivity, and a hole transport property can be suitably obtained.

Next, as specific materials for the self-assembled monolayer SAM, chemical formulas shown in the following “Chemical Formula 1” to “Chemical Formula 5” are illustrated.
Here, the substance represented by “Chemical Formula 1” is N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1′-biphenyl-4,4′-diamine (N, N ′). -diphenyl-N, N′-bis (3-methylphenyl) -1,1′-biphenyl-4,4′-diamine), the substance shown in “Chemical Formula 2” is 4,4′-bis [(p-tri Methoxysilylpropylphenyl) phenylamino] biphenyl (4,4′-bis [(p-trimethoxysilylpropylphenyl) phenylamino] biphenyl), a substance represented by “chemical formula 3” is tris (p-trimethoxysilylpropylphenyl) amine (tris ( p-trimethoxysilylpropylphenyl) amine), a substance represented by “Chemical Formula 4” is n-butyltrimethoxysilane, and a substance represented by “Chemical Formula 5” is methyltrimethoxysilane.

  As described above, the light emitting functional layer 60 includes the self-assembled monolayer SAM, the self-assembled monolayer SAM is formed on the pixel electrode 23, and the molecular configuration is preferably selected and defined. Therefore, the light emitting functional layer 60 has both light emitting ability and hole injection / transport properties.

Further, a circuit portion 11 is provided below the light emitting element as shown in FIG. The circuit unit 11 is formed on the substrate 20. That is, a base protective layer 281 mainly composed of SiO ₂ is formed on the surface of the substrate 20 as a base, and a silicon layer 241 is formed thereon. A gate insulating layer 282 mainly composed of SiO ₂ and / or SiN is formed on the surface of the silicon layer 241.

In the silicon layer 241, a region overlapping with the gate electrode 242 with the gate insulating layer 282 interposed therebetween is a channel region 241a. The gate electrode 242 is a part of the scanning line 101 (not shown). On the other hand, a first interlayer insulating layer 283 mainly composed of SiO ₂ is formed on the surface of the gate insulating layer 282 that covers the silicon layer 241 and on which the gate electrode 242 is formed.

  Further, in the silicon layer 241, a low concentration source region 241b and a high concentration source region 241S are provided on the source side of the channel region 241a, while a low concentration drain region 241c and a high concentration drain are provided on the drain side of the channel region 241a. The region 241D is provided to form a so-called LDD (Light Doped Drain) structure. Among these, the high-concentration source region 241S is connected to the source electrode 243 through a contact hole 243a that opens over the gate insulating layer 282 and the first interlayer insulating layer 283. The source electrode 243 is configured as a part of the above-described power supply line 103 (see FIG. 1, extending in the direction perpendicular to the paper surface at the position of the source electrode 243 in FIG. 5). On the other hand, the high-concentration drain region 241D is connected to the drain electrode 244 made of the same layer as the source electrode 243 through a contact hole 244a that opens through the gate insulating layer 282 and the first interlayer insulating layer 283.

The upper layer of the first interlayer insulating layer 283 on which the source electrode 243 and the drain electrode 244 are formed is covered with a second interlayer insulating layer 284 mainly composed of, for example, an acrylic resin component. The second interlayer insulating layer 284 can be made of a material other than an acrylic insulating film, such as SiN or SiO ₂ . A pixel electrode 23 made of ITO is formed on the surface of the second interlayer insulating layer 284 and is connected to the drain electrode 244 through a contact hole 23a provided in the second interlayer insulating layer 284. Yes. That is, the pixel electrode 23 is connected to the high concentration drain region 241D of the silicon layer 241 through the drain electrode 244.

  Note that TFTs (driving circuit TFTs) included in the scanning line driving circuit 80 and the inspection circuit 90, that is, N-channel type or P-channel type TFTs constituting an inverter included in the shift register among these driving circuits, for example. The structure is the same as that of the driving TFT 123 except that it is not connected to the pixel electrode 23.

The surface of the second interlayer insulating layer 284 on which the pixel electrode 23 is formed has a pixel electrode 23, a lyophilic control layer 25 mainly composed of a lyophilic material such as SiO _2, and an organic material made of acrylic, polyimide, or the like. Covered by the bank layer 221. The pixel electrode 23 includes an opening 25a provided in the lyophilic control layer 25 and a hole transport layer 70 and a light emitting functional layer 60 in the opening of the opening 221a provided in the organic bank 221. The layers are stacked in this order from the pixel electrode 23 side. In addition, “lyophilic” of the lyophilic control layer 25 in this embodiment means that the lyophilic property is higher than at least materials such as acrylic and polyimide constituting the organic bank layer 221. .
The layers from the substrate 20 to the second interlayer insulating layer 284 described above constitute the circuit unit 11.

  Note that, in the organic EL device 1 of the present embodiment, each light emitting functional layer 60 is formed so that the light emission wavelength bands correspond to the three primary colors of light in order to perform color display as described above. For example, as the light emitting functional layer 60, a red light emitting functional layer 60R whose light emission wavelength band corresponds to red, a green light emitting functional layer 60G corresponding to green, and a blue organic EL layer 60B corresponding to blue correspond to each. One pixel is provided in the display areas R, G, and B, and performs color display using these display areas R, G, and B. In addition, a BM (black matrix) (not shown) in which metallic chromium is formed by sputtering or the like is positioned between the organic bank layer 221 and the lyophilic control layer 25 at the boundary of each color display region. Has been.

Next, an example of the manufacturing method of the present invention will be described with reference to FIGS. 8 to 12 by the manufacturing method of the organic EL device 1 according to the present embodiment. In addition, each sectional drawing shown in FIGS. 8-12 is a figure corresponding to sectional drawing of the AB line in FIG.
First, as shown in FIG. 8A, a base protective layer 281 is formed on the surface of the substrate 20. Next, after an amorphous silicon layer 501 is formed on the base protective layer 281 using an ICVD method, a plasma CVD method, or the like, crystal grains are grown by a laser annealing method or a rapid heating method to form a polysilicon layer.

  Next, as shown in FIG. 8B, the polysilicon layer is patterned by photolithography to form island-like silicon layers 241, 251 and 261. Among these, the silicon layer 241 is formed in the display region and constitutes a driving TFT 123 connected to the pixel electrode 23, and the silicon layers 251 and 261 are P-channel type included in the scanning line driving circuit 80. And N-channel type TFTs (driving circuit TFTs).

  Next, a gate insulating layer 282 is formed of a silicon oxide film having a thickness of about 30 nm to 200 nm on the entire surface of the silicon layers 241, 251 and 261, and the base protective layer 281 by plasma CVD, thermal oxidation, or the like. Here, when the gate insulating layer 282 is formed using a thermal oxidation method, the silicon layers 241, 251 and 261 are also crystallized, and these silicon layers can be made into polysilicon layers.

When channel doping is performed on the silicon layers 241, 251 and 261, for example, boron ions are implanted at a dose of about 1 × 10 ¹² / cm ² at this timing. As a result, the silicon layers 241, 251 and 261 are low-concentration P-type silicon layers having an impurity concentration (calculated from the impurities after activation annealing) of about 1 × 10 ¹⁷ / cm ³ .

Next, an ion implantation selection mask is formed in a part of the channel layer of the P-channel TFT and the N-channel TFT, and in this state, phosphorus ions are ion-implanted at a dose of about 1 × 10 ¹⁵ / cm ² . As a result, high-concentration impurities are introduced into the patterning mask in a self-aligned manner, and as shown in FIG. 8C, the high-concentration source regions 241S and 261S and the high-concentration drain region are formed in the silicon layers 241 and 261. 241D and 261D are formed.

  Next, as shown in FIG. 8C, the gate electrode forming conductive layer 502 made of a metal film such as doped silicon, a silicide film, or an aluminum film, a chromium film, or a tantalum film is formed on the entire surface of the gate insulating layer 282. Form. The thickness of the conductive layer 502 is approximately 500 nm. Thereafter, as shown in FIG. 8D, a gate electrode 252 for forming a P-channel type driving circuit TFT, a gate electrode 242 for forming a pixel TFT, and an N-channel type driving circuit TFT are formed by patterning. A gate electrode 262 to be formed is formed. Further, the drive control signal conducting portion 320 (350) and the first layer 121 of the cathode power supply wiring are also formed at the same time. In this case, the drive control signal conducting portion 320 (350) is disposed in the dummy region 5.

Subsequently, as shown in FIG. 8D, phosphorus ions are ionized at a dose of about 4 × 10 ¹³ / cm ² with respect to the silicon layers 241, 251 and 261 using the gate electrodes 242, 252 and 262 as a mask. inject. As a result, low-concentration impurities are introduced in a self-aligned manner with respect to the gate electrodes 242, 252 and 262, and as shown in FIG. 8D, the low-concentration source regions 241b and 261b in the silicon layers 241 and 261, and Low concentration drain regions 241c and 261c are formed. In addition, low concentration impurity regions 251S and 251D are formed in the silicon layer 251.

Next, as shown in FIG. 9E, an ion implantation selection mask 503 that covers a portion other than the P-channel type driver circuit TFT 252 is formed. Using this ion implantation selection mask 503, boron ions are implanted into the silicon layer 251 at a dose of about 1.5 × 10 ¹⁵ / cm ² . As a result, since the gate electrode 252 constituting the TFT for the P-channel type drive circuit also functions as a mask, the silicon layer 252 is doped with a high concentration impurity in a self-aligning manner. Therefore, the low-concentration impurity regions 251S and 251D are counter-doped and become the source region and drain region of the P-type channel driver TFT.

  Next, as shown in FIG. 9 (f), a first interlayer insulating layer 283 is formed over the entire surface of the substrate 20, and the first interlayer insulating layer 283 is patterned by using a photolithography method to thereby form each TFT. A contact hole C is formed at a position corresponding to the source electrode and the drain electrode.

  Next, as shown in FIG. 9G, a conductive layer 504 made of a metal such as aluminum, chromium, or tantalum is formed so as to cover the first interlayer insulating layer 283. The thickness of the conductive layer 504 is approximately 200 nm to 800 nm. Thereafter, in the conductive layer 504, a region 240a in which the source electrode and drain electrode of each TFT are to be formed, a region 310a in which the driving voltage conducting portion 310 (340) is to be formed, and a second layer of the cathode power supply wiring are formed. A patterning mask 505 is formed so as to cover the region 122a to be formed, and the conductive layer 504 is patterned so that the source electrodes 243, 253, 263, and the drain electrodes 244, 254, 264 shown in FIG. Form.

Next, as shown in FIG. 10I, a second interlayer insulating layer 284 that covers the first interlayer insulating layer 283 on which these are formed is formed of a polymer material such as an acrylic resin. The second interlayer insulating layer 284 is preferably formed to a thickness of about 1 to 2 μm. Note that the second interlayer insulating film can be formed of SiN or SiO ₂ , and it is desirable to form the SiN film with a thickness of 200 nm and the SiO _{2 with} a thickness of 800 nm.

Next, as shown in FIG. 10J, a portion of the second interlayer insulating layer 284 corresponding to the drain electrode 244 of the driving TFT is removed by etching to form a contact hole 23a.
Thereafter, a conductive film to be the pixel electrode 23 is formed so as to cover the entire surface of the substrate 20. Then, by patterning this transparent conductive film, as shown in FIG. 11 (k), a pixel electrode 23 that is electrically connected to the drain electrode 244 through the contact hole 23a of the second interlayer insulating layer 284 is formed, and at the same time, a dummy An area dummy pattern 26 is also formed. In FIGS. 3 and 4, the pixel electrode 23 and the dummy pattern 26 are collectively referred to as a pixel electrode 23.

  The dummy pattern 26 is configured not to be connected to the lower metal wiring via the second interlayer insulating layer 284. That is, the dummy pattern 26 is arranged in an island shape and has substantially the same shape as the shape of the pixel electrode 23 formed in the actual display region. Of course, the structure may be different from the shape of the pixel electrode 23 formed in the display region. In this case, the dummy pattern 26 includes at least the one located above the drive voltage conducting portion 310 (340).

  Next, as shown in FIG. 11L, a lyophilic control layer 25, which is an insulating layer, is formed on the pixel electrode 23, the dummy pattern 26, and the second interlayer insulating film. In the pixel electrode 23, the lyophilic control layer 25 is formed so as to partially open, and hole movement from the pixel electrode 23 occurs in the opening 25a (see also FIG. 3 and FIG. 11 (m)). It is possible. On the contrary, in the dummy pattern 26 in which the opening 25a is not provided, the insulating layer (lyophilic control layer) 25 serves as a hole movement shielding layer and does not cause hole movement. Subsequently, in the lyophilic control layer 25, a BM (not shown) is formed in a concave portion formed between two different pixel electrodes 23. Specifically, a film is formed on the concave portion of the lyophilic control layer 25 by sputtering using metallic chromium.

Next, as shown in FIG. 11 (m), an organic bank layer 221 is formed so as to cover a predetermined position of the lyophilic control layer 25, specifically, the BM. As a specific method for forming the organic bank layer, for example, an organic layer is formed by applying a resist in which a resist such as an acrylic resin or a polyimide resin is dissolved in a solvent by various coating methods such as a spin coating method or a dip coating method. . The constituent material of the organic layer may be any material as long as it does not dissolve in the ink solvent described later and is easily patterned by etching or the like.
Subsequently, the organic layer is patterned using a photolithography technique and an etching technique, and a bank opening 221a is formed in the organic layer, thereby forming an organic bank layer 221 having a wall surface in the opening 221a. In this case, the organic bank layer 221 includes at least a layer positioned above the drive control signal conducting unit 320.

Next, as shown in FIG. 12 (n), the light emitting functional layer 60 is formed by the light emitting functional layer forming step.
In the light emitting functional layer forming step, a liquid phase process is adopted. The liquid phase process is a method in which a material desired to be formed is dissolved or dispersed to form a liquid, and this liquid is formed by a spin coating method, a dip method, a droplet discharge method (inkjet method), or the like. is there. The spin coating method and the dip method are suitable for the entire surface application, whereas the droplet discharge method can pattern a thin film at an arbitrary position. It is preferable that the light emitting functional layer 60 is applied on the pixel electrode 23. Moreover, as a solvent used at the said light emission functional layer formation process, a polar solvent or a nonpolar solvent is used as mentioned above.
Further, as a feature of the present invention, the material used in the light emitting functional layer forming step is a mixed material in which a light emitting material and a self-assembled monolayer material are mixed, and the mixed material is used as a material. The light emitting functional layer 60 is formed by coating on the surface of the pixel electrode 23.

  When the light emitting functional layer forming step is selectively applied by the droplet discharge method (inkjet method), first, the light emitting functional layer material (mixed liquid LQ in FIG. 6) is filled in the droplet discharge head (not shown), and the liquid While the discharge nozzle of the droplet discharge head is opposed to the electrode surface 23c located in the opening 25a formed in the lyophilic control layer 25, the droplet discharge head and the base material (substrate 20) are moved relative to each other, A droplet with a controlled liquid amount per droplet is discharged from the discharge nozzle onto the electrode surface 23c.

The liquid droplets discharged from the discharge nozzle spread on the electrode surface 23 c and fill the opening 25 a of the lyophilic control layer 25. On the other hand, droplets are repelled and do not adhere to the upper surface of the organic bank layer 221 that has been subjected to ink repellent treatment. Therefore, even if the droplet is deviated from the predetermined discharge position and discharged onto the upper surface of the organic bank layer 221, the upper surface is not wetted by the droplet, and the repelled droplet is opened in the lyophilic control layer 25. Roll into part 25a.
In addition, after this light emitting functional layer formation process, in order to prevent the oxidation of the light emitting functional layer 60, it is preferable to carry out in inert gas atmospheres, such as nitrogen atmosphere and argon atmosphere.

When droplets are thus ejected onto the surface of the pixel electrode 23 (electrode surface 23c), a self-assembled monolayer SAM is formed on the surface of the pixel electrode 23 as shown in FIG. Further, in the self-assembled monolayer SAM, the group X is arranged on the pixel electrode 23 side and the group Y is arranged on the light emitting material EM side in a self-organized manner.
Thereafter, drying treatment and heat treatment are performed to evaporate the dispersion medium and solvent contained in the light emitting functional layer material, thereby forming the light emitting functional layer 60 on the electrode surface 23c in a thin film of the order of several nm to several hundred nm, for example. The drying process is preferably performed under a condition in which a pressure is set to about 133.3 Pa (1 Torr) at room temperature in a nitrogen atmosphere. In addition, the heat treatment after the drying treatment is preferably performed under a condition of about 10 minutes at 200 ° C. in a vacuum.

  In this light emitting functional layer forming step, for example, a blue (B) light emitting functional layer forming material is selectively applied to a blue display region by the above-described droplet discharge method, dried, and then similarly green ( G) and red (R) are also selectively applied to the display area and dried. As a drying process, when coating is performed by a droplet discharge method, it is preferable to dry and evaporate by heating at 200 ° C. or lower on a hot plate. In addition, when it apply | coats by a spin coat method or a dip method, it is preferable to dry by blowing nitrogen to a board | substrate or rotating a board | substrate and generating an air current on a board | substrate surface.

  Next, as shown in FIG. 12 (o), the electron transport layers 65 and 65 are formed by the electron transport layer forming step. In the electron transport layer forming step, the above-described electron transport layer forming material is discharged and formed by the droplet discharge method.

Next, as shown in FIG. 12 (p), the cathode 50 is formed by the cathode layer forming step. In this cathode layer forming step, a cathode material such as Al is formed by, for example, vapor deposition or sputtering.
Thereafter, the sealing substrate 30 is formed by a sealing process. In this sealing step, the sealing substrate 30 and the substrate 20 are bonded to each other while the desiccant 45 is adhered to the inside of the sealing substrate 30 in order to prevent water and oxygen from entering the produced organic EL element. Sealing is performed with a sealing resin 40. As the sealing resin 40, a thermosetting resin or an ultraviolet curable resin is used. In addition, it is preferable to perform this sealing process in inert gas atmosphere, such as nitrogen, argon, and helium.

  In such a method of manufacturing the organic EL device 1, a light emitting functional layer material obtained by mixing a light emitting material and a self-assembled monolayer material is disposed on the surface of the pixel electrode 23, thereby providing a light emitting material having a light emitting ability. In addition, a self-assembled monomolecular film having hole injection / transport properties is formed on the surface of the pixel electrode. That is, it is possible to form a light emitting functional layer having hole transportability and light emitting ability in a single step. Therefore, it is not necessary to form the hole transport layer and the light emitting layer in separate steps as in the prior art, and the light emitting functional layer can be formed. Therefore, the number of steps can be reduced and the productivity can be improved.

  Further, since the liquid phase method is used in the process of forming the light emitting functional layer 60, the organic EL device can be manufactured at a low cost without using expensive equipment such as a vacuum device as compared with the gas phase method. . Further, since the droplet discharge method is used as the liquid phase method, the light emitting functional layer can be formed inexpensively and accurately.

  In the present embodiment, the back emission type has been described as an example. However, the present invention is not limited to this, and the top emission type and the type of emitting light on both sides are also described. Applicable.

In this embodiment, the self-assembled monomolecular film is formed on the surface of the pixel electrode 23. However, the self-assembled monomolecular film is not limited to the pixel electrode 23 and may be formed on the cathode surface. Good.
For example, when forming a so-called reverse structure organic EL device, the self-assembled monolayer can be formed on the cathode surface. The reverse structure here means a structure in which the positional relationship between the cathode and the anode is reversed, that is, from the substrate 20 side, the cathode 50, the electron injection layer 65, the light emitting functional layer 60, the hole transport layer, the pixel. It means a structure in which the electrodes 23 are sequentially stacked. Therefore, in such an organic EL device having a reverse structure, a liquid mixture obtained by mixing a self-assembled monolayer material with a light emitting material is formed on the cathode 50, so that the surface of the cathode 50 is subjected to the same process as described above. A self-assembled monolayer can be formed. In this way, the electron injection property to the light emitting material can be improved by the self-assembled monolayer.
Furthermore, by forming the reverse structure, it is possible to provide a top emission type organic EL device that extracts emitted light from the pixel electrode 23 side. Therefore, the aperture ratio of the light emitting area can be increased. In this case, it is necessary to employ the sealing substrate 30 and a transparent material.

Next, the electronic apparatus of the present invention will be described. The electronic apparatus of the present invention has the organic EL device 1 as a display unit, and specifically includes a mobile phone as shown in FIG.
In FIG. 13, reference numeral 1000 indicates a mobile phone body, and reference numeral 1001 indicates a display unit using the organic EL device 1.
Since the electronic device (mobile phone) illustrated in FIG. 13 includes the display portion 1001 including the organic EL device, an inexpensive electronic device can be provided.

The schematic diagram which shows the wiring structure of the organic electroluminescent apparatus of this invention. The top view which shows typically the structure of the organic electroluminescent apparatus of this invention. Sectional drawing which follows the AB line | wire of FIG. Sectional drawing which follows the CD line | wire of FIG. The expanded sectional view which shows the principal part of FIG. Schematic diagram of a self-assembled monolayer. The enlarged view which shows the principal part of FIG. Sectional drawing explaining the manufacturing method of an organic electroluminescent apparatus in order of a process. Sectional drawing for demonstrating the process following FIG. Sectional drawing for demonstrating the process following FIG. Sectional drawing for demonstrating the process following FIG. Sectional drawing for demonstrating the process following FIG. FIG. 11 is a perspective view showing an electronic apparatus of the invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Organic EL apparatus (organic electroluminescent apparatus), 23 ... Pixel electrode (anode, electrode), 50 ... Cathode (electrode), 60 ... Light emitting functional layer, 65 ... Electron transport layer, SAM ... Self-assembled monolayer

Claims (9)

An organic electroluminescence device comprising a light emitting functional layer formed between electrodes,
The light emitting functional layer has a material of a light emitting material and a self-assembled monolayer,
The self-assembled film is formed on the surface of at least one of the electrodes, and is an organic electroluminescence device. The organic electroluminescence device according to claim 1, wherein the self-assembled monomolecular film has a molecular structure represented by the following formula (1).
_{X- (CH 2) n -Y ...} (1)
X: a group bonded to the electrode Y: a group disposed on the light emitting material side The group of X is a silanol group (—Si (OH) ₃ ), a trichlorosilyl group (—SiCl ₃ ), a triethoxysilyl group (—Si (OEt) ₃ ), or a trimethoxysilyl group (—Si (OMe) _3. ), Thiol group (—SH), hydroxyl group (—OH), amino group (—NH ₂ ), phosphate group (—PO ₃ H ₂ ), carboxyl group (—COOH), sulfonic acid group (—SO ₃ H) ), A phosphoric acid chloride group (—PO ₂ Cl ₂ ), a carboxylic acid chloride group (—COCl), and a sulfonic acid chloride group (—SO ₂ Cl). The organic electroluminescence device described. The group of Y includes a methyl group (CH ₃ ), a trifluoromethyl group (CF ₃ ), an aromatic functional group, a group consisting of a benzene derivative, a group consisting of a biphenyl derivative, a group consisting of a triarylamine derivative, and a phthalocyanine derivative. The organic electroluminescence device according to claim 2, wherein the organic electroluminescence device is formed of any one of the following groups.   3. The organic electroluminescence device according to claim 2, wherein the number of n is 0 to 10. A method for producing an organic electroluminescence device comprising a light emitting functional layer formed between electrodes,
An organic electroluminescent device characterized in that the light emitting functional layer is formed by applying a mixed material in which a light emitting material and a self-assembled monolayer material are mixed to the surface of at least one of the electrodes. Production method.   The method of manufacturing an organic electroluminescence device according to claim 6, wherein the mixed material is applied by using a liquid phase method.   The method of manufacturing an organic electroluminescence device according to claim 7, wherein the liquid phase method is a droplet discharge method. An electronic apparatus comprising the organic electroluminescence device according to any one of claims 1 to 5.

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