JP2006228570A - Electroluminescent element and electroluminescent panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electroluminescent element with improved reliability. <P>SOLUTION: An upper electrode 40 of the EL element is covered with a first protective film 50 including a dense CuPc film having high covering properties, which can be formed by vacuum evaporation method, superior in sputter resistant properties and plasma resistant properties, and a second protection film 60 constituted mainly of inorganic material like SiNx, is formed on the first protective film so as to cover the whole part of a substrate. Although the protective film made of inorganic material is superior in waterproofing properties and mechanical strength, as it is formed by sputtering or CVD, there is the possibility of damaging the lower metallic layer or further lower light-emitting later 30 during film formation, and such a damage can be protected by the first protective film 50, including the CuPc film. Since the CuPc film is soft and provided with stress relaxation properties, the surface is prevented from generation of hillocks or the like, caused by heating even when an upper electrode 40 is formed of Al or the like. A laminated structure, interposing a buffer layer, may be adopted as the upper electrode 40. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electroluminescence (hereinafter referred to as EL) element, particularly an upper electrode thereof and a protective film formed thereon.

  The EL element is a self-luminous element that is bright and has a low viewing angle dependency, and a display device using the EL element can be made thinner or smaller than the liquid crystal display device, and the power consumption can be reduced. It can be kept low. For this reason, it is expected as a next-generation display device and light source, and research is being advanced. Among such EL elements, an organic EL element using an organic compound as a light-emitting material has been attracting attention because it can realize an arbitrary emission color by designing the organic compound and it is easy to realize a full color display. ing.

  The organic EL element is configured by laminating a light emitting element layer including at least one organic layer containing a light emitting material between a lower electrode and an upper electrode, one of which is an anode and the other is a cathode. For example, the lower electrode functions as an anode with a transparent electrode using a conductive transparent metal oxide such as ITO (Indium Tin Oxide), and the upper electrode functions as a cathode with a metal electrode using Al or the like. To do.

  In the organic EL element having such a structure, holes are injected from the anode side, electrons are injected from the cathode side, and the organic light emitting material in the light emitting element layer is excited by the recombination energy of the injected holes and electrons. The light obtained when returning to the ground state is used.

  Here, it is known that the organic compound contained in the light-emitting element layer is likely to be deteriorated by moisture, oxygen, and other impurities. For this reason, in order not only to prevent the organic compound from being exposed to moisture and the like during element formation, but also to prevent moisture and the like from entering the element from the outside after element formation, an EL element formed on the element substrate is used. The EL device is sealed by adhering the sealing substrate so as to cover, and thereby, the desiccant is disposed in the sealing space formed between the sealing substrate and the element substrate. In addition to sealing and disposing the desiccant, the device is covered with a protective film (passivation film) made of silicon nitride or silicon oxynitride from above the upper electrode in order to prevent impurities from entering the device (patent) It has been proposed to cover the upper electrode with an organic layer and form an inorganic protective film thereon (see Patent Document 2).

JP 2000-340801 A Japanese Patent Laid-Open No. 10-312883

  By covering the EL element with a protective film as described in Patent Documents 1 and 2 described above, it becomes possible to prevent moisture and other impurities from entering the element, suppressing deterioration of the organic compound, and reducing the element lifetime. Improvements should be made. However, the applicant's research has revealed that the element lifetime is not improved as expected even when the EL element is covered with a protective film.

  In the present invention, the electroluminescence element is covered with a protective film to improve the reliability of the element, such as the light emission lifetime.

  In the present invention, an electroluminescence device comprising a light emitting device layer containing a light emitting material between a lower electrode and an upper electrode, wherein a first protective film containing a copper phthalocyanine derivative is formed to cover the upper electrode, A second protective film is formed on the first protective film.

  In another aspect of the present invention, in the electroluminescent element, the upper electrode is a metal material containing Al at least on the interface side with the first protective film.

  In another aspect of the present invention, in the electroluminescence element, the second protective film includes a moisture blocking film formed by chemical vapor deposition or sputtering at least on the interface side with the first protective film.

  In another aspect of the present invention, in the electroluminescence element, the second protective film includes an inorganic film containing silicon atoms and nitrogen atoms at least on the interface side with the first protective film.

  In another aspect of the present invention, in the electroluminescence element, the first protective film is formed on an interface side with the second protective film, and includes a first layer containing a copper phthalocyanine complex derivative compound, the upper electrode, And an aluminum quinolinol complex derivative compound.

  In another aspect of the present invention, in the electroluminescence element, a charge injection layer is formed on a contact interface side of the light emitting element layer with the upper electrode, and the upper electrode is formed on the charge injection layer of the light emitting element layer. From the side, an upper first conductive layer formed by a vapor deposition method and an upper second conductive layer formed by a sputtering method are provided, and further, between the upper first conductive layer and the upper second conductive layer, A buffer layer protecting at least the upper first conductive layer.

  In another aspect of the present invention, there is provided an electroluminescent panel including a plurality of electroluminescent elements in a display region, each including a light emitting element layer including a light emitting material between a lower electrode and an upper electrode, and the upper part of the electroluminescent element. The electrode includes, from the light emitting element layer side, an upper first conductive layer formed by an evaporation method and an upper second conductive layer formed by a sputtering method, and further, the upper first conductive layer and the upper second conductive layer. A buffer layer is provided between the conductive layer and each of the layers of the upper electrode is formed to extend to the outside of the light emitting element layer so as to cover the terminal part of the light emitting element layer in the periphery of the display region. And the buffer layer is terminated inside the end positions of the upper first conductive layer and the upper second conductive layer, and the upper first conductive layer and the upper portion The two conductive layers are in direct contact with each other in the vicinity of the terminal portion, and a first protective film containing an organic compound having either or both of sputtering resistance and plasma resistance is formed covering the entire formation region of the upper second conductive layer. A second protective film is formed on the first protective film so as to cover the entire formation region of the element.

  In another aspect of the present invention, the buffer layer may have a laminated structure of, for example, a layer using a copper phthalocyanine complex derivative compound and a layer using an aluminum quinolinol complex derivative compound from the upper first conductive layer side. The first protective film may also have a laminated structure of a layer containing an aluminum quinolinol complex derivative compound and a layer containing a copper phthalocyanine complex derivative compound from the upper second conductive layer side.

  In the present invention, a first protective film containing a copper phthalocyanine (CuPc) derivative material is formed between the upper electrode of the EL element and the second protective film. The film containing the copper phthalocyanine derivative compound can be dense and can be formed with good coverage, and is excellent in sputtering resistance or plasma resistance. Therefore, by covering the upper electrode with the first protective film in advance, when the second protective film is formed so as to cover the upper electrode in order to protect the EL element from impurities, the upper electrode is protected by the second protective film. It is possible to prevent the light emitting element layer formed under the upper electrode from being damaged by being directly exposed to the film forming environment.

  Further, the CuPc derivative compound employed as the first protective film is an organic compound, for example, compared with an upper electrode using a metal material such as Al, a second protective film when an inorganic material is used, and the like. The membrane is soft. For this reason, by forming between the upper electrode and the second protective film, it has a stress relaxation function (buffer function) that relaxes the stress acting near the interface when they are in direct contact. For this reason, it becomes possible to prevent that an upper electrode peels off and a crack generate | occur | produces in a 2nd protective film because distortion arises between films | membranes.

  Further, when a metal material such as Al is used for the upper electrode, hillocks and pinholes are easily generated in the Al layer. When the second protective film is formed by, for example, a sputtering method or various chemical vapor deposition methods, the surface temperature of the substrate may be higher than the room temperature even when the film is formed at room temperature. For this reason, if the Al layer is exposed on the surface, hillocks and electromigration are likely to occur due to heating. However, by covering the upper electrode with the first protective film containing a CuPc derivative compound having a stress-relaxing property due to being a dense organic layer and a soft organic layer compared to the inorganic material layer, the upper electrode material Migration can be prevented, and pinholes and hillocks can be prevented from occurring.

  By forming a second protective film on the first protective film as described above and adopting a single layer or a laminated structure of a material having low moisture permeability and high mechanical strength as the second protective film material, The EL element protection function of the second protective film can be exhibited to the maximum, and the element life can be extended. Further, when the second protective film is formed, damage to the upper electrode after the film formation can be prevented, so that the charge injection efficiency into the light emitting element layer is not lowered, and the light emitting element layer is deteriorated by external moisture or the like. From this point, the device life can be extended.

  The best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described below with reference to the drawings.

[overall structure]
FIG. 1 shows a schematic cross-sectional configuration of an electroluminescent element according to an embodiment of the present invention and a display panel including the electroluminescent element, and the electroluminescent element is formed above a transparent substrate 10 such as glass or plastic. At least one light emitting element layer 30 containing a light emitting material is provided between the lower electrode 20 and the upper electrode 40.

  The lower electrode 20 is formed in the lower layer of the light emitting element layer 30. For example, a conductive transparent metal oxide such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide) is formed by sputtering to form a desired shape. A transparent electrode obtained by patterning and functions as an anode. On the other hand, the upper electrode 40 functions as a cathode in this example, and is formed on the light emitting element layer 30 and has a single layer or a laminated structure. In the example of FIG. 1, a light reflective (opaque) metal material is a main component. It is used as.

  The light emitting element layer 30 is a single layer structure including an organic compound having both a charge (hole, electron) transport function and a light emission function, or two or three layers including a charge transport layer and a light emission layer, or more. The multilayer structure can be adopted. In the example of FIG. 1, the hole injection layer 312, the hole transport layer 314, the light emitting layer 316, and the electron transport layer 318 each formed using an organic compound from the lower electrode 20 side that is an anode, and further a cathode. An electron injection layer 320 is laminated in order to relax the electron injection barrier from the upper electrode 40 to the electron transport layer 318 side and improve the electron injection efficiency. Each layer of the light emitting element layer 30 is a vapor deposition layer formed by a vacuum vapor deposition method. Note that the hole injection layer 312, the hole transport layer 314, the light emitting layer 316, and the electron transport layer 318 can be formed by the above-described vacuum deposition method when the organic compound used is a low molecular compound, respectively. When a system compound is employed, it can be formed by a method such as ink jet printing or spin coating. The electron injection layer 320 formed at the interface of the light emitting element layer 30 with the upper electrode 40 is often made of lithium fluoride (LiF) or the like, and a vacuum deposition method is used for forming this layer. be able to. Regardless of which method is used, the light emitting element layer 30 includes an organic compound and is formed of a soft film as compared with a metal film or an inorganic insulating film formed by, for example, a sputtering method.

  The upper electrode 40 is obtained by forming a metal layer such as Al, an Al alloy (AlNd, AlCNi, etc.), Ag, an Ag alloy (AgMg, etc.) by, for example, a vacuum deposition method. The upper electrode 40 is not limited to a single-layer structure, and a multi-layer structure as will be described later can be adopted. With this multi-layer structure, an EL element with better characteristics and a longer life can be obtained.

  The upper electrode 40 is preferably formed, for example, by the above-described vacuum deposition method or the like so as not to damage the light emitting element layer 30 existing in the lower layer, and at least on the interface side with the light emitting element layer 30. It is preferable to form an electrode layer. Moreover, it is preferable not to employ the patterning by the photolithography method or the like as the patterning of the upper electrode 40 because the light emitting element layer 30 is easily damaged by the etching solution or the like at the time of etching. Therefore, when the upper electrode 40 has an arbitrary desired pattern, a mask is used at the time of film formation, or a barrier or the like that can be automatically separated at the same time as the film formation of the upper electrode 40 between pixels is formed in advance on the substrate side. It is desirable to keep it.

  When each pixel is individually controlled by forming a switching element made of a thin film transistor or the like and the lower electrode 20 is connected to this switching element as an individual pattern for each pixel (in the case of a so-called active matrix EL display device), it is common to all pixels. The upper electrode 40 can be formed and no panning is required. Of course, it does not have to be common to all pixels, and for example, a configuration in which separation is performed for each horizontal scan along a horizontal scanning line (gate line) of the display device can be employed.

  In the case of a so-called passive matrix EL display device in which each pixel is not provided with a switching element, a plurality of stripes are formed so as to be orthogonal to each other with the lower electrode 20 and the upper electrode 40 sandwiched between the light emitting element layers 30. This pattern should be used. In this case, the stripe-shaped upper electrodes 40 adjacent to each other can be electrically and physically separated without any particular patterning by the barrier formed in advance on the substrate side after the formation of the lower electrode 20 as described above. .

In the present embodiment, the first protective film 50 is formed so as to cover the entire formation region of the upper electrode 40. The first protective film 50 is formed by vacuum deposition after the upper electrode 40 is formed without breaking the vacuum state, so that moisture and impurities enter the light emitting element layer 30 during the formation of the first protective film. To prevent it. The first protective film 50 has, for example, a chemical formula
A derivative compound having a copper phthalocyanine (CuPc) skeleton as shown in FIG. The first protective film 50 using CuPc is a dense film with excellent coverage, and can exhibit a sufficient protective function when the film thickness is about 5 nm to 100 nm. Here, for example, the thickness is 30 nm. The film is formed.

After the formation of the first protective film 50, the second protective film 60 is formed on the first protective film 50 so as to cover the entire substrate. The second protective film 60 is preferably a silicon nitride film (SiNx) as a compound containing silicon and nitrogen that is particularly dense and has a high moisture and impurity shielding function. Other silicon oxynitride (SiONx) films, silicon oxide (SiO ₂ ) films, inorganic films containing aluminum atoms and nitrogen atoms (aluminum nitride films), and inorganic films containing aluminum atoms and oxygen atoms (aluminum oxide films) Is also possible. The second protective film 60 is not limited to a single-layer structure, and a multi-layer structure can be adopted. However, a film made of silicon nitride that is most dense and has good coverage and does not contain oxygen is formed at least on the first protective film 50 side. Is preferred. These silicon oxynitride films and silicon oxide films are preferably employed in a laminated structure with a silicon nitride film (first protective film side). A metal layer such as Al may be further formed on the silicon nitride film, or a resin having low water permeability may be further laminated. At least the silicon nitride film constituting the second protective film 60 is formed using a CVD method such as plasma CVD, CAT (catalyst) CVD, LPCVD, or a sputtering method. The thickness is 100 nm to 1 μm, for example, about 500 nm, which is necessary for exhibiting a sufficient protective function. By forming by a CVD method or a sputtering method, it is possible to form a thick film with high coverage and uniformity and good productivity.

  When the second protective film 60 is formed by the CVD method or the sputtering method, the surface of the element is exposed to plasma or a sputtering environment, but in this embodiment, it is dense and has good coverage as described above. The first protective film 50 made of CuPc having high sputtering resistance and plasma resistance covers the upper electrode 40. Therefore, the surface of the upper electrode 40 is prevented from being damaged.

  Further, when the second protective film 60 is formed by the above-described CVD method or sputtering method, the surface temperature on the element side which is the surface to be formed is about 80 ° C. even when the film forming environment is room temperature (25 ° C.). . Al or the like used for the upper electrode 40 is likely to cause migration or hillocks at a temperature of about 80 ° C. However, migration is suppressed because the Al surface is covered with the first protective film 50 made of CuPc. It is also possible to prevent the occurrence of hillocks.

  Furthermore, when the upper electrode 40 containing Al and the silicon nitride film are in direct contact with each other, stress is likely to act on the interface due to the difference in crystal grain size in the both films, and hillocks are likely to occur. FIG. 2 (a) shows a photomicrograph showing the state of the surface (in the range of 2.8 μm × 2.8 μm) when a silicon nitride film is directly formed on the Al layer. In the direct laminated structure of Al / SiN, many hillocks having a diameter of about 300 nm on average have occurred. As shown in FIG. 2A, when hillocks, that is, deformation (strain) of the film occurs on the surface of the upper electrode 40, deformation or stress is also generated at the interface between the upper electrode 40 and the electron injection layer 320. (Distortion) occurs.

  However, by forming the first protective film 50 made of CuPc, which is a soft organic compound compared to the inorganic material, between the upper electrode 40 made of Al and the second protective film 60 made of silicon nitride, the first protective film 50 is formed. One protective film 50 can relieve stress (or strain). FIG. 2B shows a photomicrograph showing the surface (2.8 μm × 2.8 μm) when a CuPc layer is interposed between the Al layer and the SiN layer. As can be understood from the comparison with FIG. 2A, the number of hillocks generated is very small, and no large unevenness due to hillocks is observed. In the organic EL element, improvement of the electron injection efficiency from the cathode to the light emitting element layer 30 is also important from the viewpoint of improving the light emission efficiency of the element. By providing the first protective film 50 as in the present embodiment, hillocks are generated. Thus, it is possible to improve the light emission efficiency of the device by preventing the occurrence of distortion such as unevenness and stress due to hillocks at the interface between the cathode and the light emitting device layer 30.

  Note that CuPc can also be used as a material for the hole injection layer 312 of the light emitting element layer 30, for example, to reduce the hole injection barrier efficiency from the anode toward the light emitting layer 316. By adopting the material used also for the layer 30, it is not necessary to prepare a special material only for forming the first protective film 50, which contributes to improvement in manufacturing efficiency.

The first protective film 50 is not limited to a single layer structure of CuPc, and a multilayer structure of a CuPc film and a film made of another material can be adopted. Hereinafter, the multilayer structure of the first protective film 50 will be described with reference to FIG. As a material suitable for forming a multilayer with the CuPc film, there is a stress relaxation function similarly to CuPc, and the material of the light emitting element layer 30, more specifically, the electron transport layer 318 and the light emitting layer 316 are also used. An example of the organic compound used is an aluminum quinolinol complex (Alq ₃ ).

In the example shown in FIG. 3, the stacking order of the first protective film 50 is an Alq ₃ film (lower first protective film) 52, a CuPc film (upper first protective film) 54, in order from the interface side with the upper electrode 40. It has become. Both the first lower protective film 52 and the first upper protective film 54 are preferably formed continuously by vacuum deposition, and the lower first protective film 52 is formed by using Alq ₃ in succession to the formation of the upper electrode 40. Then, the upper first protective film 54 is formed using CuPc. The number of laminated first protective films 50 is not limited to two layers as shown in FIG. 3, but is dense and has good coverage and protects the lower layer from the environment when the second protective film 60 is formed. It is necessary to employ the CuPc.

When the electrode material (metal layer or conductive transparent oxide layer) formed by sputtering and an organic film that easily absorbs moisture are in contact with each other, the organic film is deformed or altered by moisture absorption, so that the organic film is transformed from the electrode material layer to the organic film. Peeling easily occurs. Here, CuPc has high water resistance, but the Alq ₃ has higher water resistance than CuPc, and a contact interface with the upper electrode 40 is formed using the film using Alq ₃ as a lower first protective film. By providing on the side, peeling between the upper electrode 40 and the first protective film can be prevented. In particular, when the upper second conductive layer 44 is formed by sputtering or the like using Al or the like, the upper second conductive layer 44 hardly absorbs moisture. This peeling can be prevented. Then, an upper first protective film 54 made of CuPc that is dense and has good covering properties is laminated so as to cover the first lower protective film 52 made of Alq ₃ , so that the sputtering environment and the plasma environment when forming the second protective film 60 are removed. It becomes possible to more reliably protect the upper electrode 40 and the lower light emitting element layer 30 more reliably.

The first protective film 50 is not limited to a structure in which an Alq ₃ film and a CuPc film are laminated in order from the upper electrode 40 side. For example, an electrode material on at least the surface side of the upper electrode 40 is not a sputtering method but a vacuum evaporation method. In contrast, the CuPc film may be formed on the upper electrode 40 side, and the Alq ₃ film may be formed thereon. The thicknesses of the lower and upper first protective films 52 and 54 are not particularly limited. For example, both the lower and upper first protective films 52 and 54 are formed to a thickness of about 5 nm to 100 nm, for example, 30 nm. The protective function can be demonstrated.

  As can be seen from the comparison of FIG. 2 described above, as to the degree of hillock generation, the first protective film 50 of CuPc is provided between the Al upper electrode 40 and the second protective film 60 of SiNx as in the present embodiment. By providing, the degree of hillock generation in the Al upper electrode 40 can be made very low. Since hillocks can be prevented in this way, damage to the second protective film 60 due to hillocks and distortion of the interface between the upper electrode 40 and the light emitting element layer 30 can be prevented, and high reliability and high luminous efficiency can be realized. Is possible.

  For example, the effect of suppressing the generation of hillocks also leads to the effect of suppressing the generation of pinholes in the protective film formed on the Al layer, that is, the original function of the protective film. Table 1 below shows a case where a protective film made of silicon nitride is directly formed on the upper electrode 40 using Al, and a protective film (first film) made of the Al upper electrode 40 and the silicon nitride film according to the present embodiment. 2 shows a comparison of the number of pinholes generated after the first protective film 50 made of CuPc is formed between the two protective films 60 and after being exposed to the etching solution for Al for a certain period.

  As is clear from the results in Table 1, the number of pinholes generated can be reduced by interposing the first protective film 50 using CuPc between the upper electrode 40 and the second protective film 60 made of SiNx. The number of pinholes generated when a silicon nitride film is directly formed thereon is reduced to a quarter. It can be understood that the generation of pinholes on the surfaces of the Al upper electrode layer and the first protective film 50 is prevented by suppressing the occurrence of hillocks and the like in the Al layer by the first protection 50. Thus, since it can suppress that a pinhole generate | occur | produces in the 1st protective film 50, the 1st protective film 50 can continue covering the lower Al upper electrode 40 with sufficient covering property and adhesiveness. Therefore, the upper electrode 40 can be protected from the formation environment of the second protective film 60, and the characteristics and lifetime of the element can be improved.

[Configuration of upper electrode]
Next, a specific example in which a multilayer structure is employed as the upper electrode 40 covered with the first protective film 50 and the second protective film 60 will be described. The upper electrode 40 can be formed of a single metal layer such as Al. As shown in FIG. 4, the upper first conductive layer 42 formed by vapor deposition and the upper second conductive formed by sputtering. And a lower layer than the upper second conductive layer 44 (here, the upper first conductive layer 42 and the light emitting element below the upper first conductive layer 44). A three-layer structure with a buffer layer 46 protecting layer 30) can be employed.

  Specifically, on the electron injection layer 320 made of LiF of the light emitting element layer 30, a thickness of about 5 nm to 50 nm (as an example, 10 nm as the upper first conductive layer 42 by a vacuum deposition method continuously. An Al layer (Al vapor-deposited layer) formed to a thickness of

  On the upper first conductive layer 42, an organic layer containing CuPc formed in a thickness of about 5 nm to 100 nm (for example, a thickness of 30 nm as an example) by a vacuum deposition method is continuously formed as the buffer layer 46. ing.

  On the buffer layer 46, a sputtering method is used to form a metal layer having a thickness of about 0.2 nm to 400 nm, for example, 300 nm, for example, Al, Al alloy (for example, AlNd), Mo, Ti, A metal layer made of a refractory metal material such as Cr or an alloy thereof can be used as the upper second conductive layer 44. Here, as the upper second conductive layer 44, specifically, an Al layer formed by sputtering is used.

  The thickness of each layer of the upper electrode 40 is such that the upper first conductive layer 42 is formed by vapor deposition. Therefore, if it is too thick, productivity cannot be improved, and if it is too thin, the coverage and smoothness of the deposited film are low. Therefore, it cannot be uniformly formed in a necessary region. Therefore, it is preferable that the upper first conductive layer 42 has a thickness of at least about 5 nm to 50 nm as described above, for example, so that electrons can be reliably injected into at least the electron injection layer 320.

  The buffer layer 46 is preferably formed by, for example, a vacuum deposition method so as not to damage the lower layer below the layer, so that productivity is not lowered and lower layer protection as described later is performed. The thickness is about 5 nm to 100 nm as described above so that it has a thickness necessary to exert its function, and does not increase the resistance of the entire upper electrode 40 so much and does not impair the electron injection function. It is preferable to do.

  The upper second conductive layer 44 is formed by a sputtering method, and it is possible to form a relatively thick layer with high coverage and uniformity and high productivity. The thickness of the upper second conductive layer 44 is the thickness necessary for preventing the occurrence of disconnection and electric field concentration as an electrode, and reducing the resistance value of the entire electrode to reduce heat generation and voltage drop. The thickness setting range is, for example, about 0.2 nm to 400 nm, but it may be thicker or thinner depending on the nature of the metal material used.

The buffer layer 46 as described above has a function of preventing damage to the light emitting element layer 30 located in the lower layer when formed. In order to protect the lower layer when the upper second conductive layer 44 is sputtered, the buffer layer 46 is preferably a dense and stable film so that it is not completely removed by sputtering. As a material that satisfies such conditions, an organometallic complex, particularly a chelate complex compound, such as CuPc as described above, is preferable. As the buffer layer 46, in addition to such CuPc, Alq ₃ which is also a chelate complex compound can also be employed, and the layer structure is, for example, a single layer structure of CuPc or Alq ₃ , which will be described later. Thus, a multilayer structure of CuPc or Alq may be used.

  In the case where an Al layer is used as the upper second conductive layer 44 and the upper first conductive layer 42, if both the conductive layers 42 and 44 are in direct contact with each other, the upper second conductive layer 44 located at the uppermost layer has an Al layer or the like. When a hillock peculiar to is generated, deformation or stress (strain) is also generated at the interface between the upper first conductive layer 42 and the electron injection layer 320 due to the hillock. By providing the buffer layer 46 between the conductive layers 44 and 42, the strain between the conductive layers 44 and 42 can be alleviated and hillock generation can be prevented.

  When a refractory metal material such as Mo is directly formed on the upper first conductive layer 42, which is an Al deposited layer, by sputtering, the upper second conductive layer 44 is denser than the deposited Al layer. In addition, a stress is generated between the upper second conductive layer 44 and the upper first conductive layer 42 which have a large coefficient of thermal expansion and a large amount of heat generated when the element is driven. However, such strain can be alleviated by employing the buffer layer 46.

Since CuPc and Alq ₃ employed for the buffer layer 46 all have a charge transporting function, the degree of interference with charge movement in the upper electrode 40 is suppressed to a low level, and the element is driven by the buffer layer 46 interposed. The increase in voltage can be reduced, and as a result, it can contribute to the improvement of the light emission efficiency of the organic EL element.

  Further, a laminated structure in which the buffer layer 46 is interposed as described above is adopted as the upper electrode 40, and the upper second conductive layer 44 formed by sputtering of the upper electrode 40 is used as the first protective film 50 containing CuPc. And is covered with a second protective film made of SiNx or the like. Therefore, the generation of distortion such as hillocks caused by direct contact between the metal surface of the upper electrode 40 formed by sputtering and the second protective film 60 is suppressed, and the upper electrode 40 is removed from the sputtering or plasma environment when the second protective film 60 is formed. It is possible to realize an EL element which is protected and has high luminous efficiency and has a long lifetime and high reliability.

  The element substrate 10 is completed by covering the EL element having the above configuration formed on the element substrate with the first protective film 50 and the second protective film 60 as in the present embodiment. As shown in FIG. 4, a sealing substrate 70 made of, for example, a transparent glass substrate is adhered to the element forming surface side of the element substrate by using an adhesive 80 at the periphery of the panel, thereby being covered with a protective film. The EL element is further shielded from the outside by a sealing substrate, and can prevent intrusion of impurities such as moisture and improve mechanical strength. The element substrate 10 and the sealing substrate 70 are bonded only at the periphery of the element formation region, and thereby the space formed in the element formation region is sealed with dry nitrogen at the time of sealing (a desiccant is added). Or a water-resistant liquid such as silicone oil may be enclosed. Further, an adhesive resin or the like may be applied to the entire surface of the element substrate on the element formation surface side (the surface of the second protective film 60) to adhere the sealing substrate.

  In addition, if the first protection film 50 and the second protection film 60 are formed so as to cover the elements, and the element protection and sealing from the outside are sufficiently achieved, the first and second protection films 50 and 60 are achieved. The EL element substrate covered with may be used as it is for a display panel or the like. In the case where the sealing substrate 70 is not bonded in this way, the second protective film 60 is not a SiNx single layer, and a metal layer such as Al is further formed covering the SiNx film, or a resin or the like. A protective layer made of an insulating protective polymer material may be laminated. If the second protective film 60 has an element protection function to such an extent that the sealing substrate can be omitted, a very thin display panel can be realized by omitting the sealing substrate.

  In the organic EL element having the structure as described above, holes are injected from the anode side, electrons are injected from the cathode side, and the organic light emitting material in the light emitting layer 316 is changed by the recombination energy of the injected holes and electrons. The light obtained when excited and returned to the ground state is used. Here, in the organic EL element shown in FIG. 4, a light-reflective (opaque) metal material such as Al or an alloy thereof is formed on both the upper first conductive layer 42 and the upper second conductive layer 44 of the upper electrode 40. Used. Therefore, the light obtained by the light emitting layer 316 and traveling to the transparent lower electrode 20 is transmitted through the lower electrode 20 (the light traveling to the upper electrode 40 side is once reflected by the upper electrode 40 and proceeds to the lower electrode 20). In addition, the light passes through the substrate 10 made of transparent glass, plastic, or the like and is emitted to the outside for visual recognition.

  When a light-emitting display device is configured using the organic EL elements as described above, each pixel is provided with an organic EL element and a thin film transistor (TFT) as a switching element for individually controlling light emission from the organic EL element. A so-called active matrix display device can realize high-definition and high-quality display. In such an active matrix display device, a TFT of a pixel for driving the organic EL element is formed between the substrate 10 and the lower electrode 20 of the organic EL element, that is, before the organic EL element is formed. Yes. In the so-called bottom emission type display device that emits light through the substrate from the lower electrode 20 side of the organic EL element as described in FIGS. 1 to 4, when a TFT or the like is formed in each pixel, The TFT and the organic EL element are laid out so that light from the organic EL element is emitted from the substrate 10 to the outside in the TFT non-formation region.

  Here, the organic EL element is not limited to the bottom emission type, and may be a so-called top emission type organic EL element that emits light from the second protective film 60 side. In the case of a top emission type organic EL element (display device), a configuration as shown in FIG. 5 can be adopted. That is, by making the upper electrode 40 transparent and forming the light reflection layer 22 such as an Al layer between the lower electrode 20 and the substrate 10, the light traveling from the light emitting layer 316 to the lower electrode side 20 can be reflected by the lower reflective layer 22 and emitted from the upper electrode 40 side.

  Further, when the upper electrode 40 is used as a cathode, the lower electrode 20 and the light emitting element layer 30 can adopt the same structure as the bottom emission type described above (different materials may be used). In this case, since the upper first conductive layer 42 formed on the electron injection layer 320 needs to exhibit an electron injection function, it is necessary to employ a metal having a low work function. The metal is usually opaque, but for example, Al or an alloy thereof, Ag or an alloy thereof, Au, or the like is employed, and these are formed thin enough to transmit light, or an opening region is provided to form a mesh or a lattice. Light can be transmitted from the opening region.

The upper first conductive layer 42 is preferably formed by vacuum deposition as described above from the viewpoint of protecting the light emitting element layer 30. A light transmissive buffer layer 46 such as CuPc, Alq _3, or a laminate thereof is formed on the upper first conductive layer 42 configured to transmit light in this manner, and the transparent upper first layer is covered with the buffer layer 42. As the second conductive layer 48, a transparent conductive metal oxide material such as ITO or IZO is formed. Since the upper first conductive layer 42 and the underlying light emitting element layer 30 are protected by the buffer layer 46, the ITO or the like is formed to a sufficient thickness by using, for example, a general sputtering method as its formation method. be able to. In this way, the transparent upper electrode 40 can be realized. Here, the thickness of the upper first conductive layer 42 made of, for example, an Ag layer by vapor deposition is about 20 nm. Similarly, the buffer layer 46 made of CuPc by vapor deposition is about 10 nm, and the transparent upper second conductive layer 48 made of ITO is: The thickness may be about 80 nm to 100 nm.

Thus, even in the case of the top emission type display device, of course, the first protective film 50 including at least the CuPc film is formed by vacuum deposition so as to cover the upper second conductive layer 44 made of the transparent conductive metal oxide. In the example of FIG. 5, the first protective film 50 has a two-layer structure including a lower first protective film 52 and an upper first protective film 54 using CuPc from the upper first conductive layer 42 side. A second protective film 60 made of SiNx or the like is formed on the first protective film 54 by covering the entire substrate by sputtering or CVD. Thus, since the upper second conductive layer 44 is covered with the first protective film 50, the upper second conductive layer 44 is prevented from being damaged by the environment when the second protective film 60 is formed, and both are made of an inorganic material. Because the first protective film 50 containing CuPc that is soft, dense, and has good coverage is formed between the upper second conductive layer 44 and the second protective film 60, as described above, the first protective film 50 is caused by the distortion of the interface. It can be surely prevented that the light emitting efficiency of the EL element is reduced or the protective performance is deteriorated due to a crack in the second protective film 60. Note that either a single layer of CuPc or a stacked structure of CuPc and Alq ₃ employed as the first protective film 50 is light transmissive, and SiNx used as the second protective film 60 is also highly light transmissive. Therefore, even in the case of a top emission type display device in which the upper electrode 40 is a light transmissive electrode, as in the case of the bottom emission type, a sufficient protective function can be exhibited and the element characteristics and life can be improved.

[Buffer layer and first protective film]
FIG. 6 shows a configuration in which the first protective film 50 is multi-layered and the buffer layer 46 in the upper electrode 40 is multi-layered. Specifically, each of the first protective film 50 and the buffer layer 46 has a two-layer structure, and the buffer layer 46 is a first buffer layer 462 using CuPc on the upper first conductive layer 42 side. The upper second conductive layer 44 side formed by sputtering is a second buffer layer 464 using Alq ₃ . The first protective film 50 is a lower first protective film 52 using Alq ₃ on the upper second conductive layer 44 side, and an upper first protective film 54 using CuPc on the second protective film 60 side. In this way, the Alq ₃ film 52 of the first protective film 50 and the Alq ₃ film 464 of the buffer layer are symmetrically formed on the upper and lower layers with the upper second conductive layer 44 interposed therebetween, and each of them further includes CuPc films 54 and 462. It touches. Accordingly, even when the EL element is driven and the upper electrode 40, in particular, the thick and highly conductive upper second conductive layer 44 generates heat, the thermal expansion coefficients of the upper and lower layers of the conductive layer 44 are equal. The stress due to the difference is balanced between the upper and lower surfaces of the conductive layer 44. Therefore, it is possible to prevent the upper second conductive layer 44 from being deformed unilaterally to the element substrate side or the second protective film 60 side, and to prevent the upper electrode 40 from peeling or cracking more reliably. Therefore, it is possible to prevent the outside light from entering the inside of the upper electrode 40 from peeling or cracking to damage the light emitting element layer 30 and spreading the dark spots.

[Panel periphery]
Next, the configuration of the peripheral part of the EL panel according to the present embodiment will be described with reference to FIG. 6 and FIG. FIG. 7 conceptually shows a planar configuration of the periphery of the EL panel as shown in FIG.

  The panel shown in FIG. 6 is an active matrix type in which each pixel is provided with a TFT, and the end of the lower electrode 20 connected to the TFT and formed in an individual shape for each pixel is covered with a planarization insulating layer 24. . The end portion of the lower electrode 20 of the pixel at the outermost position of the panel display region is also covered with the planarization insulating layer 24. In this example, the light emitting element layer 30 is formed in common for each pixel so that other layers (312 314 318 320) excluding the light emitting layer 316 get over the planarization insulating layer 24, and In the end portion of the display region, each layer of the light emitting element layer 30 formed in common for a plurality of pixels is formed at least up to the planarization insulating layer 24. In the example of FIG. 6, the planarization insulating layer 24 is formed further to the outside than the end of the display area.

  When a white light-emitting material is used for the light-emitting layer 316, a color filter or the like corresponding to each pixel is provided, and the light-emitting layer 316 is common to a plurality of pixels like the other constituent layers of the light-emitting element layer 30 in FIG. It is also possible to form. In addition, a specific layer other than the light emitting layer 316 or the entire layer may be formed in an independent pattern for each pixel depending on the characteristics of the organic EL element, the organic material to be used, and the like.

  In any case, the light emitting element layer 30 is formed up to the vicinity of the end of the display portion where the pixels are arranged. In the vicinity of the end of the display portion, the light emitting element layer 30 enters moisture from the outside or the like. Is more likely to receive.

  However, in the example shown in FIGS. 6 and 7, the upper electrode 40 is first formed to the outside of the region where the light emitting element layer 30 is formed in the periphery of the panel, and the side surface of the terminal portion of the light emitting element layer 30 is formed on the upper electrode. Covered with layers. Specifically, the upper first conductive layer 42 is formed in a pattern extending to the outside of the light emitting display element layer 30 so as to cover the display region end of the light emitting element layer 30. As described above, this pattern can be obtained by using a metal mask or the like that opens to the outside of the formation range of the light emitting element layer 30 when the upper first conductive layer 42 is formed by vacuum deposition.

Next, the first buffer layer 462 and the second buffer layer 464 are continuously formed on the upper first conductive layer 42 using a mask having an opening pattern smaller than that of the upper first conductive layer 42. To do. Therefore, the buffer layer 46 has a pattern that terminates inside the end portion of the upper first conductive layer 42. Here, the second buffer layer 464 is used to Alq _3, the second buffer layer 464 of the Alq ₃ so as to cover the end portion of the first buffer layer 462, that is greater than the first buffer layer 462 Form. As a result, the second buffer layer 464, which has better moisture resistance than the first buffer layer 462 using CuPc, completely covers the first buffer layer 462, and the upper second conductive layer 44 and the first second conductive layer 44 formed thereon are formed. There is no region in contact with the buffer layer 462, and the upper second conductive layer 44 and the first buffer layer 462 are prevented from peeling off due to deformation due to moisture absorption. Note that the first buffer layer 462 and the second buffer layer 464 can be formed using the same mask. In this case, the second buffer layer 464 is formed more than the first buffer layer 462 is formed. The position of the mask disposed between the element substrate and the vapor deposition source is shifted to the vapor deposition source side so that the formation pattern of the second buffer layer 464 is larger than that of the first buffer layer 462.

  On the second buffer layer 464, the upper second conductive layer 44 is formed by sputtering in a pattern that is larger than the pattern and substantially the same size as the upper first conductive layer 42 that has already been formed. By making the upper first and second conductive layers 42 and 44 larger than the buffer layer 46, the buffer layer 46 is terminated inside the end positions of the upper first and second conductive layers 42 and 44, and at the periphery of the panel. The upper first conductive layer 42 and the upper second conductive layer 44 can be brought into direct contact and can be electrically connected.

  For this reason, a structure is employed in which a buffer layer 46 using an organometallic complex material or the like having a high charge resistance compared to a metal material is inserted between the first and second conductive layers 42 and 44. Even so, sufficient power can be supplied to the upper first conductive layer 42 in contact with the light emitting element layer 30 and injecting charges (here, electrons). The upper first conductive layer 42 and the upper second conductive layer 44 are connected to an external power source (Vc) (not shown) via terminals formed on the panel.

  The buffer layer 46 (462, 464) protects both the lower upper first conductive layer 42 and the light emitting element layer 30, and at least a region where the light emitting element layer 30 is formed in the lower layer and a terminal portion thereof. It is necessary to completely cover the upper part. Even if the upper first conductive layer 42 is exposed to the sputtering film formation environment of the upper second conductive layer 44, it is possible to ensure electrical connection between the two conductive layers, and the light emitting element layer 30 is disposed in the lower layer. The buffer layer 46 may not be interposed between the upper first and second conductive layers 42 and 44 in the vicinity of the edge of the display portion that does not exist. If the contact distance between the upper first conductive layer 42 and the upper second conductive layer 44 is, for example, about 300 μm, a sufficient electrical connection can be obtained, and the buffer layer 46 is located about 300 μm from the end position of the upper first conductive layer 42. Terminate with.

  After the formation of the upper electrode 40, the first protective film 50 is formed so as to cover the upper electrode 40 continuously by vacuum deposition. The first protective film 50 is formed larger than the pattern of the upper first and second conductive layers 42 and 44, but covers at least the side surfaces of the upper first and second conductive layers 42 and 44 that terminate at substantially the same position. In order to prevent moisture from entering from the outside and to more reliably protect the upper electrode 40 from the environment when the second protective film 60 is formed, the upper first and second conductive layers 42 and 44 are It forms to the outside from the side position. Accordingly, the first protective film 50 is formed under the lower electrode 20 and is in direct contact with the planarization insulating layer 18 exposed on the uppermost surface when the first protective film 50 is formed in the periphery of the panel.

In the example of FIG. 6, the first protective film 50 is configured by laminating the lower first protective film (Alq ₃ film) 52 and the upper first protective film (CuPc film) 54 sequentially from the upper electrode 40 side as described above. Has been. The relationship between the sizes of the patterns of the lower and upper first protective films 52 and 54 is not particularly limited as long as the upper electrode 40 is completely covered as the first protective film 50. However, at least the CuPc film 54 having higher hygroscopicity than the Alq ₃ film 52 comes into contact with the upper second conductive layer 44 formed by sputtering, and the CuPc film 54 is deformed by moisture absorption, so that the upper second conductive layer 44 and It is preferable that an Alq ₃ film is always interposed between the upper second conductive layer 44 and the CuPc film 54 in order to reliably prevent peeling at the interface. Therefore, although there is no particular problem if the first protective film 50 is formed to be sufficiently larger than the upper electrode 40, the upper first protective film 54 using CuPc is slightly more than the pattern of the lower first protective film 52 using Alq _3. It is more reliable if the pattern is made small.

  Here, a SiNx second protective film 60 is formed on the entire surface of the substrate covering the first protective film 50 by plasma CVD. Therefore, the second protective film 60 is formed up to the outermost side of the panel. Note that, at positions where electrodes, signal lines, and the like need to be connected to the outside, the second protective film 60 and the first protective film 50 may be removed by etching after the second protective film 60 is formed.

  As described above, after the upper electrode 40 is completely covered with the first protective film 50, the second protective film 60 is formed so as to cover almost the entire surface of the substrate, so that the upper electrode 40 is formed from the upper surface and side surfaces thereof. Can protect. Further, in addition to the first and second protective films 50 and 60, the upper electrode 40 is formed in a multilayer structure, and the buffer layer 46 is interposed therebetween, thereby improving the light emission efficiency and reliability of the device, and emitting light. It is possible to more reliably prevent moisture and oxygen from entering the element layer and further extend the element life. In addition, since the first protective film 50 and the buffer layer 46 have a symmetric multilayer structure with respect to the upper second conductive layer 44, the deformation of the upper second conductive layer 44 can be prevented as described above.

  As shown in FIG. 6, a planarization insulating layer 18 is formed under the lower electrode 20 of the EL element, and the planarization insulating layer 18 is formed so as to cover the end of the lower electrode 20. The same acrylic resin as that of the planarization insulating layer 24 is used. The first protective film 50 and the second protective film 60 are in contact with the planarization insulating layer 18 at the periphery of the panel, and the EL element is connected to the planarization insulating layer 18 and the first and second protective films 50 and 60. It is completely covered and sealed. When the hygroscopicity of the planarization insulating layer 18 becomes a problem, for example, the planarization insulating layer 18 is terminated before the panel peripheral portion (for example, a sealing position by a sealing substrate).

As a result, in the peripheral portion of the panel, the surface of the interlayer insulating film 16 formed under the planarization insulating layer 18 and composed of a stack of the SiNx film and the SiO ₂ film is exposed from the lower layer side. The surface may be completely covered with the first protective film 50 and the second protective films 50 and 60. Here, a buffer layer 2 having a laminated structure of a SiN film and a SiO ₂ film is formed on the substrate 10 from below, and a predetermined position on the buffer layer 2 is formed by, for example, laser annealing that constitutes an active layer of the TFT. A polycrystallized crystalline silicon layer 4 is formed. A gate insulating film 6 having a laminated structure of SiO ₂ film and SiNx film is formed in order from the lower layer so as to cover the crystalline silicon layer 4, and an interlayer insulating film is formed on the gate insulating film 6 in the TFT non-formation region. 16 is formed. Therefore, when the structure in which the planarization insulating layer 18 is removed at the peripheral portion of the panel and the interlayer insulating film 16 is directly covered with the first protective film 50 and the second protective film 60 as described above is employed, each layer of the TFT and EL element is used. Are all made of an inorganic film of SiO2 or SiNx and the periphery thereof is sealed, so that intrusion of water, oxygen and the like from the substrate side from the substrate side can be prevented more reliably.

It is a figure which shows the schematic cross section of the EL display panel which concerns on embodiment of this invention. It is a microscope picture of the laminated structure of an Al layer and a silicon nitride film, and the laminated structure of an Al layer, a CuPc layer, and a silicon nitride film. It is a schematic sectional drawing which shows another example and FIG. 1 about the 1st protective film of the EL element panel which concerns on embodiment of this invention. FIG. 4 is a schematic cross-sectional view showing another example of the upper electrode of the EL display panel according to the embodiment of the present invention, different from FIGS. 1 and 3. FIG. 5 is a schematic cross-sectional view showing an example of the EL display panel according to the embodiment of the present invention, which is different from FIGS. 1 and 3 to 4. FIG. 6 is a schematic cross-sectional view showing another example of the first protective film and the buffer layer of the EL display panel according to the embodiment of the present invention, different from FIGS. 1 and 3 to 5. It is a figure which shows the schematic planar structure of the panel peripheral part of the display panel of FIG.

Explanation of symbols

  2 buffer layer, 4 TFT active layer, 6 gate insulating film, 8 gate electrode, 10 substrate, 14 gate insulating film, 16 interlayer insulating film, 18, 24 planarizing insulating layer, 20 lower electrode, 22 reflective layer, 30 light emitting element Layer, 40 upper electrode, 42 upper first conductive layer, 44 upper second conductive layer, 46 buffer layer, 50 first protective film, 52 lower first protective film, 54 upper first protective film, 60 second protective film, 462 1st buffer layer, 464 2nd buffer layer, 312 Hole injection layer, 314 Hole transport layer, 316 Light emitting layer, 318 Electron transport layer, 320 Electron injection layer.

Claims (12)

An electroluminescence device comprising a light emitting device layer containing a light emitting material between a lower electrode and an upper electrode,
A first protective film including a copper phthalocyanine derivative is formed to cover the upper electrode;
An electroluminescence element, wherein a second protective film is formed to cover the first protective film. The electroluminescent device according to claim 1,
The electroluminescent element according to claim 1, wherein at least an interface side of the upper electrode with the first protective film is a metal material containing Al. The electroluminescent device according to claim 1 or 2,
The electroluminescent element, wherein the second protective film includes a moisture block film formed by chemical vapor deposition or sputtering at least on the interface side with the first protective film. In the electroluminescent element of any one of Claims 1-3,
The second protective film is an inorganic film containing silicon atoms and nitrogen atoms, an inorganic film containing silicon atoms and oxygen atoms, an inorganic film containing aluminum atoms and nitrogen atoms, or aluminum at least on the interface side with the first protective film. An electroluminescent device comprising an inorganic film containing atoms and oxygen atoms. In the electroluminescent element as described in any one of Claims 1-4,
The first protective film includes
A first layer formed on an interface side with the second protective film and containing a copper phthalocyanine complex derivative compound;
An electroluminescence element comprising: a second layer formed on an interface side with the upper electrode and containing an aluminum quinolinol complex derivative compound. In the electroluminescent element of any one of Claims 1-5,
A charge injection layer is formed on the contact interface side of the light emitting element layer with the upper electrode,
The upper electrode includes an upper first conductive layer formed by a vapor deposition method and an upper second conductive layer formed by a sputtering method from the charge injection layer side of the light emitting element layer, and further includes the upper first conductive layer. An electroluminescence device comprising a buffer layer protecting at least the upper first conductive layer between a conductive layer and the upper second conductive layer.   The electroluminescent device according to claim 6, wherein the buffer layer contains a copper phthalocyanine derivative compound. An electroluminescence panel comprising a plurality of electroluminescence elements provided in a display region with a light emitting element layer containing a light emitting material between a lower electrode and an upper electrode,
The upper electrode of the electroluminescence element includes, from the light emitting element layer side, an upper first conductive layer formed by a vapor deposition method and an upper second conductive layer formed by a sputtering method. A buffer layer is provided between the conductive layer and the upper second conductive layer,
In the periphery of the display area, each layer of the upper electrode is formed to extend to the outside of the light emitting element layer, covering the terminal part of the light emitting element layer,
In addition, the buffer layer is terminated inside the end positions of the upper first conductive layer and the upper second conductive layer, and the upper first conductive layer and the upper second conductive layer are directly connected to each other near the end portion. Touched,
A first protective film including an organic compound having either or both of sputtering resistance and plasma resistance is formed to cover the entire formation region of the upper second conductive layer;
An electroluminescence panel, wherein a second protective film is formed on the first protective film so as to cover the entire formation region of the element.   The electroluminescence panel according to claim 8, wherein the buffer layer and the first protective film include a copper phthalocyanine complex derivative compound. In the electroluminescent panel according to claim 8 or 9,
The buffer layer includes a first buffer layer including the copper phthalocyanine derivative compound formed on the interface side with the upper second conductive layer, and an aluminum quinolinol complex derivative formed on the interface side with the upper first conductive layer. A second buffer layer containing a compound,
The second buffer layer is formed between the first buffer layer and the upper second conductive layer, and the second buffer layer is formed at a peripheral portion of the display area than an end portion of the first buffer layer. An electroluminescence panel, which extends to the outside and covers a terminal portion of the first buffer layer. The electroluminescence panel according to claim 10,
The first protective film has a laminated structure, a lower first protective film including the aluminum quinolinol complex derivative compound is formed on an interface side with the upper second conductive layer, and an interface side with the second protective film And an upper second protective film containing the copper phthalocyanine complex derivative compound.   The electroluminescent panel according to any one of claims 8 to 11, wherein at least the upper second conductive layer contains aluminum.