JP2012216810A - Organic el element and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL element that allows suppression of the uneven light emission and the reduction in luminance occurring in a pixel, and to provide a method of manufacturing the same.SOLUTION: An organic EL element comprises: a substrate 101; a first electrode 102 formed on the substrate 101; a partition wall 103 formed on the substrate 101 and surrounding the periphery of the first electrode 102; a light-emitting medium layer 108 formed on the first electrode 102 in the partition wall 103 and constituting a pixel; and a second electrode 109 formed on the partition wall 103 and the light-emitting medium layer 108. When the thickness of an organic light-emitting sublayer 106 of the light-emitting medium layer 108 gradually becomes thick toward the partition wall 103 from the center of the pixel, the thickness of an electron injection sublayer 107 formed on the organic light-emitting sublayer 106 is also formed so as to gradually become thick toward the partition wall 103 from the center of the pixel, and in the reverse case, the thickness of the electron injection sublayer 107 is formed so as to gradually become thin toward the partition wall from the center of the pixel.

Description

The present invention relates to an organic EL (electroluminescence) element and a manufacturing method thereof, and more particularly to an organic EL element using an EL phenomenon of an organic thin film and a manufacturing method thereof.

An organic EL element has a structure in which an organic light emitting layer exhibiting at least an EL phenomenon is sandwiched between an electrode as an anode and an electrode as a cathode, and a voltage is applied between the electrodes (anode and cathode). Then, holes and electrons are injected into the organic light emitting layer, and the holes and electrons are recombined in the organic light emitting layer, whereby the organic light emitting layer emits light.
The organic EL element as described above has a hole injection layer, a hole transport layer, or between the organic light emitting layer and the cathode between the anode and the organic light emitting layer for the purpose of increasing luminous efficiency. In addition, an electron transport layer, an electron injection layer, and the like are appropriately selected and provided. And the layer which combined the organic light emitting layer and the hole injection layer mentioned above, a hole transport layer, an electron transport layer, an electron injection layer, etc. is called the organic light emitting layer.

In addition, the organic light emitting material forming the organic light emitting layer includes a low molecular material and a polymer material. In general, a low molecular material is formed into a thin film by a vacuum deposition method or the like, and is patterned using a fine pattern mask. In this method, the patterning accuracy increases as the substrate becomes larger. There is a problem that it is difficult. Further, in the formation of a thin film by a vacuum deposition method or the like, there is a problem that the throughput is poor because the film is formed in a vacuum.

Thus, recently, a method of forming a thin film by dissolving the polymer material in a solvent to form a coating liquid and using the coating liquid by a wet coating method has been tried. When a light emitting medium layer including an organic light emitting layer is formed by a wet coating method using a coating material of a polymer material, the layer structure is a two-layer structure in which a hole transport layer and an organic light emitting layer are laminated from the anode side. It is common.
At this time, in order to make the organic light emitting layer into a color panel, organic light emitting materials having respective emission colors of red (R), green (G), and blue (B) are dissolved in a solvent or stable. Thus, it is necessary to coat them separately using an organic light-emitting ink that is dispersed.

In the conventional organic EL element as described above, for example, as shown in FIG. 5, when the organic light emitting layer 106 is formed by a wet coating method, it is provided to insulate the first electrode 102 (pixel electrode). Since the thin film formed by the wet coating method is thickened along the shape of the partition wall 103, the flatness of the organic light emitting layer 106 is deteriorated. FIG. 5 is a cross-sectional view showing a schematic configuration of a conventional organic EL element 100.

For this reason, there is a problem in that the light emission in the pixel becomes non-uniform and the total luminance in the pixel is reduced with respect to the peak luminance in one pixel. Furthermore, when the thickness of the organic light emitting layer is increased to a certain extent, the conductivity of the organic light emitting layer is deteriorated and a portion that does not emit light is generated. As a method for solving such a problem, for example, a method for making the film thickness of the organic light emitting layer uniform as shown in Patent Document 1 below has been proposed.

In Patent Document 1, as a method of increasing the flatness of the film thickness of the organic light emitting layer by an ink jet method, a bank is previously formed on a substrate with a material having ink repellency using a photolithography method or the like. A method is disclosed in which ink droplets are landed on the bank, whereby ink is repelled in accordance with the bank shape and a linear pattern is obtained. However, the method disclosed in Patent Document 1 has a problem in that when the repelled ink returns to the inside of the pixel, the ink rises inside the pixel and the thickness of the organic light emitting layer in the pixel varies. is there.

Moreover, as a method different from the method disclosed in Patent Document 1, in Patent Document 2 below, only the anode is made to emit light by selectively forming the hole transport layer only on the anode, A method for making the light emitting region of the light emitting pixel uniform has been proposed.

JP 2002-305077 A JP 2008-71872 A

However, in the method disclosed in Patent Document 2, it is possible to make the light emitting region uniform, but since the film thickness distribution exists in the organic light emitting layer, pixels generated in the light emitting region formed by the organic light emitting layer It is difficult to suppress light emission unevenness and luminance reduction.
In the present invention, in the luminescent medium layer provided in the organic EL element, the organic EL element capable of suppressing light emission unevenness and luminance reduction in the pixel due to the low flatness of the organic light emitting layer and its manufacture It aims to provide a method.

Of the present invention, the invention described in claim 1 includes a substrate, a first electrode formed on the substrate, a partition wall formed on the substrate and surrounding the periphery of the first electrode, and the interior of the partition wall. A light emitting medium layer that is formed on the first electrode and constitutes a pixel, and a second electrode formed on the partition wall and the light emitting medium layer, wherein the light emitting medium layer includes: Except for the electron injection layer, at least one electron injection injection layer having a non-uniform thickness is formed on the light-emitting medium layer whose thickness decreases or increases as it approaches the center of the pixel from the partition wall. An organic EL element characterized by comprising:

Next, of the present invention, the invention described in claim 2 is the invention described in claim 1, wherein the light emitting medium layer includes a hole injection layer formed under the organic light emitting layer. It is characterized by.
Next, of the present invention, the invention described in claim 3 is the invention described in claim 1 or 2, wherein the electron injection layer uses a compound of an alkali metal and an alkaline earth metal. It is characterized by being formed.

Next, among the present inventions, the invention described in claim 4 is the invention described in claim 1 or 2, wherein the electron injection layer is formed using an organic substance. To do.

Next, among the present inventions, the invention described in claim 5 is the invention described in any one of claims 1 to 4, wherein the light emission intensity of the organic light emitting layer is greater than the center of the pixel. When the partition wall side decreases, the thickness of the electron injection layer is made uniform from the center of the pixel to the region where the emission intensity decreases by 10%, and the thickness of the electron injection layer on the partition wall side from the region where the emission intensity decreases by 10%. When the thickness is increased and the emission intensity of the organic light emitting layer increases on the partition side from the center of the pixel, the thickness of the electron injection layer is made uniform from the center of the pixel to a region where the emission intensity increases by 10% and the emission intensity is 10%. The thickness of the electron injection layer on the partition wall side is reduced from the increasing region.

Next, among the present inventions, the invention described in claim 6 is a region in which when the light emitting film thickness of the organic light emitting layer is thicker on the partition side than the center of the pixel, the film thickness is 5 nm thicker than the center film thickness of the pixel. The thickness of the electron injection layer on the partition side is increased from the region where the thickness of the electron injection layer is uniform and the thickness is 5 nm or more from the center, and the emission intensity of the organic light emitting layer is increased on the partition side from the center of the pixel. In this case, the thickness of the electron injection layer is made uniform from the center of the pixel to the region where the film thickness is reduced by 5 nm, and the thickness of the electron injection layer on the partition wall side is reduced from the region where the film thickness is reduced by 5 nm or more. It is a feature.

Next, among the present inventions, the invention described in claim 7 is a method for manufacturing an organic EL element according to any one of claims 1 to 6, wherein the organic EL element is manufactured. At least one of the layers included in the light emitting medium layer is formed using a wet process method.

According to the present invention, an organic EL panel having a film thickness distribution can be formed so as to change the film thickness of the electron injection layer in accordance with the film thickness distribution of the organic light emitting layer. It is possible to increase the electron injecting property in the thick part and to reduce the electron injecting property in the thin part. For this reason, it is possible to reduce luminance and unevenness generated in the pixel.

It is explanatory drawing which shows one Embodiment of the organic EL element of this invention, (a) is a longitudinal cross-sectional view of an organic EL element with a thin pixel center film thickness of an organic light emitting layer, (b) is a pixel center film of an organic light emitting layer. It is a longitudinal cross-sectional view of a thick organic EL element. It is a longitudinal cross-sectional view which shows the detailed structure of a board | substrate. It is a schematic block diagram of the relief printing apparatus used for a relief printing method. FIG. 4A is a metal mask pattern used for forming an electron injection layer, where FIG. 5A is a metal mask for an electron injection layer when the pixel center film thickness of the organic light emitting layer is thin, and FIG. It is a metal mask for electron injection layers when it is thick. It is explanatory drawing which shows an example of the conventional organic EL element, (a) is a longitudinal cross-sectional view of an organic EL element with a thin pixel center film thickness of an organic light emitting layer, (b) is a thick pixel center film thickness of an organic light emitting layer. It is a longitudinal cross-sectional view of an organic EL element.

(First embodiment)
Hereinafter, a configuration of an organic EL element according to the present embodiment and a method for manufacturing the organic EL element according to the first embodiment of the present invention (hereinafter referred to as “this embodiment”) will be described with reference to the drawings. .
(Constitution)
First, the structure of the organic EL element 100 of this embodiment is demonstrated using FIG. FIG. 1 is a cross-sectional view showing a schematic configuration of an organic EL element 100 of the present embodiment. As shown in FIG. 1, the organic EL element 100 includes a substrate 101, a first electrode 102, a partition wall 103, a light emitting medium layer 106, and a second electrode 109. In the present embodiment, as an example, a case where an active matrix driving type organic EL element in which the first electrode 102 is an anode and the second electrode 109 is a cathode will be described. In this case, the first electrode 102 is formed as a pixel electrode partitioned by the partition 103 for each pixel, and the second electrode 109 is formed as a counter electrode formed on the entire surface of the element. In addition, the configuration of the organic EL element 100 is not limited to the above configuration. For example, a passive matrix matrix in which each electrode (the first electrode 102 and the second electrode 109) is formed in a perpendicular stripe shape. A driving type organic EL element may be used. Alternatively, the first electrode 102 may be a cathode and the second electrode 109 may be an anode.

(Detailed configuration of the board)
Hereinafter, the detailed configuration of the substrate 101 will be described with reference to FIG. 1 and FIG. 2. FIG. 2 is a cross-sectional view illustrating a detailed configuration of a thin film transistor (TFT) 200 used as the substrate 101. In the present embodiment, the case where a TFT substrate provided with a first electrode and a partition is used as the substrate 101 will be described as an example. A substrate 101 provided in the organic EL element 100 of the present embodiment is provided with a thin film transistor 200 and a first electrode 201 (pixel electrode). The thin film transistor 200 and the first electrode 102 are electrically connected. The thin film transistor 200 is supported by a substrate 101 (support). As the substrate 101, any material can be used as long as it has mechanical strength and insulation and is excellent in dimensional stability.

Here, examples of the material of the substrate 101 include plastic films and sheets such as glass, quartz, polypropylene, polyethersulfone, polycarbonate, cycloolefin polymer, polyarylate, polyamide, polymethylmethacrylate, polyethylene terephthalate, and polyethylene naphthalate. Can be used.
Examples of the material of the substrate 101 include the above plastic films and sheets, metal oxides such as silicon oxide and aluminum oxide, metal fluorides such as aluminum fluoride and magnesium fluoride, silicon nitride, and aluminum nitride. Translucent substrate made of metal nitride, silicon oxynitride such as silicon oxynitride, polymer resin film such as acrylic resin, epoxy resin, silicone resin, polyester resin, etc., aluminum, stainless steel, etc. It is possible to use a metal foil, a sheet, a plate, or the like.

Further, as the material of the substrate 101, for example, a non-translucent base material in which a metal film such as aluminum, copper, nickel, and stainless steel is laminated on the plastic film or sheet described above can be used.
Here, the translucency of the substrate 101 may be selected depending on which surface the light is extracted from.

The substrate 101 made of the above material has been subjected to moisture-proofing treatment or hydrophobic treatment by forming an inorganic film or applying a fluororesin in order to avoid moisture intrusion into the organic EL element 100. Is preferred. In particular, in order to prevent moisture from entering the light emitting medium layer 106, it is preferable to reduce the moisture content and the gas permeability coefficient of the substrate 101.
As the thin film transistor 200, a known thin film transistor can be used. Specifically, a thin film transistor including an active layer 203 in which a source / drain region and a channel region are formed, a gate insulating film 204, and a gate electrode 205 is mainly mentioned. Here, the structure of the thin film transistor 20 is not particularly limited, and examples thereof include a staggered type, an inverted staggered type, a top gate type, and a coplanar type. The configuration of the active layer 22 is not particularly limited. For example, the active layer 22 is made of an inorganic semiconductor material such as amorphous silicon, polycrystalline silicon, microcrystalline silicon, cadmium selenide, thiophene oligomer, poly (p- It can be formed of an organic semiconductor material such as ferylene vinylene).

The active layer 203 is formed using, for example, the methods described in the following (a) to (c).
(A) A method of laminating amorphous silicon by plasma CVD and ion doping. Specifically, using SiH ₄ gas, amorphous silicon is formed by LPCVD, amorphous silicon is crystallized by solid phase growth to obtain polysilicon, and then ion doping is performed by ion implantation.
(B) Amorphous silicon is formed by LPCVD using Si ₂ H ₆ gas or PECVD using SiH ₄ gas, annealed by a laser such as an excimer laser, and then amorphous silicon is crystallized to form poly After silicon is obtained, ion doping is performed by an ion doping method (low temperature process).
(C) Polysilicon is laminated by low pressure CVD or LPCVD, thermally oxidized at 1000 [° C.] or higher to form a gate insulating film, and an n + polysilicon gate electrode 8 is formed thereon. Ion doping method (high temperature process).

As the gate insulating film 204, a film generally used as a gate insulating film can be used. That is, the gate insulating film 204, for example, PECVD method, SiO2 and formed by the LPCVD method or the like, a polysilicon film can be used such as SiO ₂ obtained by thermal oxidation. As the gate electrode 205, what is generally used as the gate electrode 205 can be used. That is, examples of the material of the gate electrode 205 include metals such as aluminum and copper (refractory metals such as titanium, tantalum, and tungsten), polysilicon, silicides of refractory metals, polycides, and the like. Note that the structure of the thin film transistor 200 may be a single gate structure, a double gate structure, or a multi-gate structure having three or more gate electrodes. Moreover, you may have a LDD structure and an offset structure. Further, two or more thin film transistors may be arranged in one pixel.

Moreover, the organic EL element 100 of this embodiment needs to be connected so that the thin film transistor 200 functions as a switching element of the organic EL element 100. Therefore, the drain electrode 207 of the thin film transistor 200 and the first electrode 102 are electrically connected. In FIG. 2, reference numeral 206 is assigned to the source electrode, reference numeral 208 is assigned to the scanning line, and reference numeral 209 is assigned to the transistor insulating film interposed between the thin film transistor 200, the first electrode 102, and the partition wall 103. is doing.

(Detailed configuration of the first electrode)
Hereinafter, the detailed configuration of the first electrode 102 will be described with reference to FIGS. 1 and 2. The first electrode 102 is formed by patterning on the substrate 101 and is partitioned by the partition wall 103 to form a pixel electrode corresponding to each pixel. Examples of the material of the first electrode 102 include metal composite oxides such as ITO (indium tin composite oxide), indium zinc composite oxide, and zinc aluminum composite oxide, metal materials such as gold and platinum, and these metal oxides. In addition, it is possible to use either a single layer or a laminate of a fine particle dispersion film in which fine particles of a metal material are dispersed in an epoxy resin, an acrylic resin, or the like.

Here, when the first electrode 102 is used as an anode, it is preferable to select a material having a high work function such as ITO. In particular, in the normal organic EL element 100, since light is emitted through the anode, the anode is required to be transparent, and a conductive metal oxide such as ITO is used. Further, when the organic EL element 100 has a so-called top emission structure in which light is extracted from above, it is not necessary to be transparent, but conductive metal oxidation such as ITO and IZO (indium and zinc composite oxide). The first electrode 102 may be formed using an object.

Further, when a conductive metal oxide such as ITO is used as the material of the first electrode 102, it is preferable to use a reflective electrode (Cr, A1, Ag, Mo, W, etc.) having a high reflectance underneath. . In this case, since the resistivity of the reflective electrode is lower than that of the conductive metal oxide, the reflective electrode functions as an auxiliary electrode and reflects light emitted from the organic light emitting layer 106 described later to the second electrode 109 side. It is possible to make effective use of light. In addition, when the organic EL element 100 has a so-called bottom emission structure in which light is extracted from below, it is necessary to select a light-transmitting material. Furthermore, if necessary, a metal material such as copper or aluminum may be provided as an auxiliary electrode in order to reduce the wiring resistance of the first electrode 102.

(Detailed configuration of partition walls)
Hereinafter, the detailed configuration of the partition wall 103 will be described with reference to FIGS. 1 and 2. The partition wall 103 is formed on the substrate 101 and is formed so as to partition the light emitting region corresponding to the pixel by surrounding the periphery of the first electrode 102. Here, in general, in the active matrix driving type organic EL element 100, the first electrode 102 is formed for each pixel (sub-pixel), and each pixel tries to occupy as wide an area as possible. Therefore, the most preferable shape of the partition wall 103 formed so as to cover the end portion (side surface) of the first electrode 102 is basically a lattice shape that divides the first electrode 102 by the shortest distance.

Moreover, the material of the partition 103 contains at least an ethylenically unsaturated compound, a photopolymerization initiator, and an alkali-soluble binder. Furthermore, the material of the partition wall 103 preferably contains a surfactant or the like, and also contains a solvent. A preferable height of the partition wall 103 is in a range of 0.1 [μm] to 10 [μm], and more preferably in a range of 0.5 [μm] to 2 [μm]. . The reason is that if the height of the partition wall 103 is too high, the formation and sealing of the second electrode 109 (counter electrode) is prevented, and if the height of the partition wall 103 is too low, the end of the first electrode 102 is completely covered. This is because there is no color mixing with adjacent pixels when the light emitting medium layer 106 is formed.

Examples of the cross-sectional shape of the partition wall 103 include a trapezoidal shape such as a forward tapered shape and a reverse tapered shape, a semicircular shape, and the like, and may have a multistage shape. Here, when the cross-sectional shape of the partition wall 103 is a multi-stage shape, even if the lower stage on the lower substrate side and the upper stage on the upper substrate side are different materials / formation methods, the same material / formation method is used. Also good. In this case, for example, the lower stage is made of an inorganic material such as SiN, and the upper stage is made of the above-described material.

(Detailed structure of the light emitting medium layer)
Hereinafter, the detailed configuration of the light emitting medium layer 106 will be described with reference to FIGS. 1 and 2. The light emitting medium layer 106 is formed on the first electrode 102 in the partition wall 103 and sandwiched between the first electrode 102 and the second electrode 109, and includes a hole injection layer 104, an organic light emitting layer 106, and the like. The electron injection layer 107 and the interlayer layer 105 are included. The hole injection layer 104 constitutes a carrier injection layer for injecting electrons or holes. The hole injection layer 104 is formed on the first electrode 102 and the partition wall 103, specifically, on the first electrode 102 and the entire surface of the partition wall 103. And so as to cover. As a result, the film shape in the pixel region becomes flat, and the film thickness for each pixel can be made uniform. The detailed configuration of the hole injection layer 104 will be described later.

The organic light emitting layer 106 is a layer that contributes to light emission, and is formed on the hole injection layer 104. That is, the hole injection layer 104 is formed under the organic light emitting layer 106. In the case of FIG. 1 a, the organic light emitting layer 106 has the thinnest pixel center and becomes thicker toward the partition wall 103. Further, the organic light emitting layer 106 in the case of FIG. 1B has the thickest center of the pixel and becomes thinner toward the partition wall 103. The detailed configuration of the organic light emitting layer 106 will be described later.

The electron injection layer 107 is a layer for injecting electrons, and is formed on the organic light emitting layer 106. Further, the film thickness of the electron injection layer 107 has a distribution from the center of the pixel to the partition wall, similar to the film thickness of the organic light emitting layer 106. A detailed configuration of the electron injection layer 107 will be described later.
The interlayer 105 is formed between the hole injection layer 104 and the organic light emitting layer 106 and is stacked with the hole injection layer 104 and the organic phosphor layer 14. Further, the interlayer layer 105 forms an electron injection layer and an electron block layer. Further, the light emitting medium layer 108 is formed on the first electrode 102 in the partition wall 103, whereby the organic EL element 100 can be arranged as a pixel (sub pixel), and an image display device can be obtained. It becomes possible. That is, a full-color display panel is manufactured by coating the organic light emitting layer 106 constituting each pixel, for example, in three colors of R (red), G (green), and B (blue) without mixing colors. Is possible.

(Detailed structure of hole injection layer)
Hereinafter, the detailed configuration of the hole injection layer 104 will be described with reference to FIGS. 1 and 2. The thickness of the hole injection layer 104 is preferably in the range of 20 [nm] to 100 [nm]. This is because short defects are likely to occur when the thickness of the hole injection layer 104 is thinner than 20 [nm], and the resistance is increased when the thickness of the hole injection layer 104 exceeds 100 [nm]. This is to reduce the current. Examples of the material of the hole injection layer 104 include polyaniline derivatives, polythiophene derivatives, polyvinylcarbazole (PVK) derivatives, poly (3,4-ethylenedioxythiophene) (PEDOT), and the like. These materials are dissolved or dispersed in a solvent, and the hole injection layer 104 is formed by using various coating methods using a spin coater or the like and a relief printing method.

When an inorganic material is used as the material for the hole injection layer 104, examples of the inorganic material include Cu ₂ O, Cr ₂ O ₃ , Mn ₂ O ₃ , FeOx (x to 0.1), NiO, CoO, Pr ₂ O ₃ , Ag ₂ O, MoO ₂ , Bi ₂ O ₃ , ZnO, TiO ₂ , SnO ₂ , ThO ₂ , V ₂ O ₅ , Nb ₂ O ₅ , Ta ₂ O ₅ , MoO ₃ , WO ₃ , MnO An inorganic material such as ₂ is used. Then, the hole injection layer 104 is formed by vapor deposition or sputtering. However, the above materials are not limited to these.

(Detailed configuration of organic light emitting layer)
Hereinafter, the detailed configuration of the organic light emitting layer 106 will be described with reference to FIGS. 1 and 2. The organic light emitting layer 106 emits light by recombining holes and electrons. When the display light emitted from the organic light emitting layer 106 is monochromatic, it is formed so as to cover the interlayer layer 105. In order to obtain multicolor display light, it can be suitably used by performing patterning as necessary.

Examples of the organic light-emitting material forming the organic light-emitting layer 106 include coumarin-based, perylene-based, pyran-based, anthrone-based, porphyrin-based, quinacridone-based, N, N′-dialkyl-substituted quinacridone-based, naphthalimide-based, N, N ′. -Diaryl substituted pyrrolopyrrole, iridium complex and other luminescent dyes dispersed in polymers such as polystyrene, polymethyl methacrylate, polyvinylcarbazole, polyarylene, polyarylene vinylene and polyfluorene Although polymeric materials are mentioned, in this embodiment, it is not limited to these materials.

Moreover, said organic luminescent material becomes organic luminescent ink by melt | dissolving in a solvent or disperse | distributing stably. Here, examples of the solvent for dissolving or dispersing the organic light emitting material include toluene, xylene, acetone, anisole, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and the like, or a mixed solvent thereof. In particular, aromatic organic solvents such as toluene, xylene, and anisole are preferable from the viewpoint of the solubility of the organic light emitting material.
Moreover, surfactant, antioxidant, a viscosity modifier, a ultraviolet absorber, etc. may be added to said organic light emitting ink as needed.

(Detailed configuration of electron injection layer)
Hereinafter, the detailed configuration of the electron injection layer 107 will be described with reference to FIGS. 1 and 2. As a material of the electron injection layer 107, for example, a material having a high work function and high electron injection efficiency into the organic light emitting layer 106 is used. In this case, specific materials include compounds of alkali metals and alkaline earth metals such as LiF, BaF ₂ , and CsF. Besides this, examples of the material of the electron injection layer 107 include organic materials. as it does not including but A1q ₃ limit.

Further, in the case of FIG. 1 a where the emission intensity of the organic light emitting layer 106 decreases in the direction from the center of the organic light emitting layer 106 toward the partition wall 103, the electron injection layer 107 is thick from the 10% reduction region to the partition wall 103. It is formed to become. On the other hand, in the case of FIG. 1 b where the emission intensity of the organic light emitting layer 106 increases from the center of the organic light emitting layer 106 toward the partition wall 103, the organic light emitting layer 106 is formed so as to become thinner from the region increasing 10% to the partition wall 103. ing.

Here, in the case of FIG. 1 a where the thickness of the organic light emitting layer 106 increases from the center of the organic light emitting layer 106 toward the partition wall 103, the light emission intensity of the organic light emitting layer 106 increases from the region where the thickness of the center of the pixel is 5 nm. Therefore, the electron injection layer 107 is formed so that the electron injection layer 107 is thicker from the region having a thickness of 5 nm from the center film thickness of the pixel to the partition wall 103. As described above, the electron injection layer is thickened in the region where the film thickness required for high electron injection property is thick, thereby improving the electron injection efficiency from the electron injection layer. Light emission unevenness and driving voltage can be reduced.
On the other hand, in the case of FIG. 1B in which the film thickness of the organic light emitting layer 106 decreases in the direction from the center of the organic light emitting layer 106 toward the partition wall 103, the light emission intensity of the organic light emitting layer 106 is from a region 5 nm thinner than the center film thickness of the pixel. In order to increase by 10 [%], the electron injection layer 107 is formed so that the electron injection layer 107 is thinned from the region 5 nm thinner than the center film thickness of the pixel to the partition wall 103. In this way, in the thin region where the light emission luminance is likely to be high, the electron injection efficiency from the electron injection layer is suppressed by thinning the electron injection layer, so that the light emission luminance is suppressed. Light emission unevenness and driving voltage in the central region can be reduced.

(Detailed configuration of the second electrode)
Hereinafter, the detailed configuration of the second electrode 109 will be described with reference to FIGS. 1 and 2. The second electrode 109 is formed on the substrate 2 and the light emitting medium layer 108 and faces the first electrode 102. Here, for example, the second electrode 109 is formed so as to cover the entire partition wall 103 and the light emitting medium layer 108 in order to prevent water and oxygen from entering the electron injection layer 107. As a material of the second electrode 109, when the second electrode 109 is a cathode, for example, a single metal such as Mg, Al, Yb or the like is used.

(About sealed body)
When the organic EL element 100 is formed by the above-described top emission method, in order to extract display light emitted through the sealing body on the side opposite to the substrate 101 from the light emitting medium layer 108, the visible light wavelength region is taken out. , Light transparency is required. Further, the organic EL element 100 can emit light by sandwiching a light emitting material (light emitting medium layer 108) between electrodes (first electrode 102, second electrode 109) and passing an electric current. The organic light emitting material which is the material 106 is easily deteriorated by moisture and oxygen in the atmosphere. For this reason, normally, the organic EL element 100 is provided with a sealing body (not shown) for shielding from the outside. Such a sealing body can be formed by providing a resin layer on a sealing material, for example.

As a material for the sealing material, it is necessary to use a base material having low moisture and oxygen permeability. Here, examples of the material for the sealing material include ceramics such as alumina, silicon nitride, and boron nitride, glass such as alkali-free glass and alkali glass, quartz, and a moisture-resistant film. Examples of the moisture-resistant film include a film in which SiOx is formed on both surfaces of a plastic substrate by a CVD method, a film having a low permeability and a water absorption property, or a polymer film coated with a water absorbing agent. Here, the moisture permeability of the moisture resistant film is preferably 1 × 10 ⁻⁶ [g / m ² / day] or less.

Examples of the material of the resin layer include a photo-curing adhesive resin, a thermosetting adhesive resin, a two-component curable adhesive resin, and an ethylene ethyl acrylate (EEA) made of an epoxy resin, an acrylic resin, a silicon resin, or the like. ) Acrylic resins such as polymers, vinyl resins such as ethylene vinyl acetate (EVA), thermoplastic resins such as polyamide and synthetic rubber, and thermoplastic adhesive resins such as acid-modified products of polyethylene and polypropylene. .

Examples of the method for forming the resin layer on the sealing material include a solvent solution method, an extrusion lamination method, a melt / hot melt method, a calendar method, a nozzle coating method, a screen printing method, a vacuum laminating method, and a hot roll. The laminating method etc. can be mentioned. In this case, it is possible to contain a hygroscopic or oxygen-absorbing material as necessary. Here, the thickness of the resin layer formed on the sealing material is arbitrarily determined depending on the size and shape of the organic EL display device to be sealed, but the thickness is within the range of 5 [μm] to 500 [μm]. Is preferred.

In the above description, the sealing body is formed as a resin layer on the sealing material. However, the sealing body can be directly formed on the organic EL element 100 side. In addition, the organic EL element 100 and the sealing body are bonded together in a sealing chamber. Here, when the sealing body has a two-layer structure of a sealing material and a resin layer, and a thermoplastic resin is used for the resin layer, it is preferable to perform only pressure bonding with a heated roll. On the other hand, when a thermosetting adhesive resin is used for the resin layer, it is preferable to perform heat curing at a curing temperature after pressure bonding with a heated roll. Moreover, when using a photocurable adhesive resin for a resin layer, after crimping | bonding with a roll, it can harden | cure by further irradiating light.

In addition, before performing sealing using the sealing material as described above, instead of using a thin film such as a silicon nitride film using a dry process such as an EB vapor deposition method or a CVD method, for example, as a passivation film. It is also possible to use a sealing body. Moreover, it is also possible to use the sealing body which combined these. In this case, the thickness of the passivation film described above can be in the range of 100 [nm] to 500 [nm]. In particular, the thickness of the passivation film is preferably in the range of 150 [nm] or more and 300 [nm] or less, although it varies depending on the moisture permeability of the material, water vapor light permeability, and the like. In addition, when the organic EL element 100 has the above-described top emission type structure, it is necessary to consider light transmission in addition to the above characteristics, so that the total average in the visible light wavelength region is 70% or more. Any is suitable.

(Manufacturing method of organic EL element)
Hereinafter, the manufacturing method of the organic EL element 100 will be described with reference to FIGS. 1 and 2 and FIG. When manufacturing the organic EL element 100, first, a first electrode forming step of forming the first electrode 102 on the substrate 101 is performed. That is, the method for manufacturing the organic EL element 100 includes a first electrode forming step. In the first electrode formation step, the first electrode 102 is formed by a resistance heating vapor deposition method, an electron beam vapor deposition method, a reactive vapor deposition method, an ion plating method, a sputtering method, depending on the material of the first electrode 102. It is possible to use a dry film forming method such as. As a method for forming the first electrode 102, it is possible to use a gravure printing method, a wet film forming method such as a screen printing method, or the like in addition to the dry film forming method.

Here, as a patterning method of the first electrode 102, an existing patterning method such as a mask vapor deposition method, a photolithography method, a wet etching method, or a dry etching method is used depending on the material of the first electrode 102 and the film forming method. It is possible. Note that in the case where a substrate on which the TFT 200 is formed (see FIG. 2) is used as the substrate 101, the substrate 101 is formed so as to be conductive corresponding to the lower pixel.

And after forming the 1st electrode 102 on the board | substrate 101, the partition formation process which forms the partition 103 surrounding the circumference | surroundings of the 1st electrode 102 on the board | substrate 101 is performed. That is, the method for manufacturing the organic EL element 100 includes a partition formation step. In the partition formation step, as a method of forming the partition 103 on the substrate 101 on which the first electrode 102 is formed, for example, an inorganic film is uniformly formed on the substrate 101 on which the first electrode 102 is formed and masked with a resist. Thereafter, a method of performing dry etching, a method of laminating a photosensitive resin on the substrate 101 on which the first electrode 102 is formed, and a method of forming a predetermined pattern by a photolithography method can be given.

Further, if necessary, a water repellent is added to the material of the partition wall 103, or plasma or UV is irradiated to give the partition wall 103 liquid repellency to the ink after the partition wall 103 is formed. It is also possible. After the partition wall 103 is formed on the substrate 101 by the partition wall forming process, the light emitting medium layer forming process for forming the light emitting medium layer 108 on the first electrode 102 is performed. That is, the method for manufacturing the organic EL element 100 includes a light emitting medium layer forming step.

The light emitting medium layer forming step includes a hole injection layer forming step for forming the hole injection layer 104 so as to cover the first electrode 102, and an organic light emitting layer forming for forming the organic light emitting layer 106 on the hole injection layer 104. And an electron injection layer forming step of forming the electron injection layer 107 on the organic light emitting layer 106.
In the hole injection layer forming step, the material of the hole injection layer 104 is dissolved or dispersed in a solvent according to the material of the hole injection layer 104, and various coating methods using a spin coater, slit coating method, spray coating, etc. A method of forming by a method, a bar coating method, a dip coating method, a relief printing method or a method of forming by a resistance heating vapor deposition method is used.

In addition to these methods, for example, dry heating methods such as resistance heating vapor deposition, electron beam vapor deposition, reactive vapor deposition, ion plating, and sputtering, and wet chemical such as spin coating and sol-gel methods. An existing film formation method such as a film method may be used. That is, at least one of the layers (the hole injection layer 104, the organic light emitting layer 106, and the electron injection layer 107) included in the light emitting medium layer 108 may be formed using a wet process method.

In the organic light emitting layer forming step, an existing film forming method such as a wet film forming method such as an ink jet printing method, a nozzle print printing method, a relief printing method, a gravure printing method, or a screen printing method is used depending on the material of the organic light emitting layer 106. Use. In particular, when the organic light emitting layer 106 is applied to each light emitting color using an organic light emitting ink in which an organic light emitting material is dissolved or stably dispersed in a solvent, the ink is transferred between the partition walls 103 and patterned. An inkjet method, a nozzle printing method, and a relief printing method that can be used are suitable.

That is, in the organic light emitting layer forming step, an organic light emitting material in which an organic light emitting material as a material of the organic light emitting layer 106 is dissolved or dispersed in a solvent on the hole injection layer 104 formed so as to cover the first electrode 102. The organic light emitting layer 106 is patterned and formed by applying ink. The organic light emitting layer forming step is performed using any one of a printing method, an inkjet method, and a nozzle printing method. Note that the organic light emitting layer 106 may be formed using a method other than the above-described film forming method.

Here, the procedure for forming the organic light emitting layer 106 by the above-described relief printing method will be described with reference to FIG. FIG. 3 is a diagram showing a schematic configuration of a relief printing apparatus 300 used in the relief printing method.
As shown in FIG. 3, the relief printing apparatus 300 performs pattern printing of an organic light emitting ink made of an organic light emitting material on a substrate 101 on which a first electrode 102, a hole injection layer 104, and an interlayer layer 105 are formed. And an ink tank 301, an ink chamber 302, an anilox roll 303, and a plate cylinder 306 on which a relief plate 305 having projections is mounted.

The ink tank 301 contains an organic light-emitting ink diluted with a solvent, and the organic light-emitting ink is fed into the ink chamber 302 from the ink tank 301. The anilox roll 303 is in contact with the ink supply unit of the ink chamber 302 and is rotatably supported by the ink chamber 302.
When the pattern printing is performed, the ink layer 304 of the organic light-emitting ink supplied to the surface of the anilox roll 303 is formed with a uniform film thickness as the anilox roll 303 rotates. The ink of the ink layer 304 is transferred to the convex portion of the relief plate 305 mounted on the plate cylinder 306 that is driven to rotate in the vicinity of the anilox roll 303. The substrate 307 to be printed (substrate 101) is placed on the stage 308, and the ink on the convex portion of the relief plate 305 is printed on the substrate 307 to be printed (substrate 101), and a drying process is performed as necessary. As a result, the organic light emitting layer 106 is formed on the substrate 101.

Note that even when another light emitting medium layer (for example, the interlayer layer 105) is applied as an ink, it is possible to form a layer on the substrate 101 using the same formation method as described above. Here, in the organic EL element 100 of the present embodiment, the light emitting medium layer 108 includes an interlayer layer 105 in addition to the hole injection layer 104, the organic light emitting layer 106, and the electron injection layer 107. For this reason, in this embodiment, the interlayer layer formation process which forms the interlayer layer 105 is performed as a post process of an organic light emitting layer formation process. That is, in this embodiment, the light emitting medium layer forming step includes an interlayer layer forming step for forming the interlayer layer 105.

In the step of forming the interlayer layer 105, when the interlayer layer 105 is formed, as a material for the interlayer layer 105, polyvinylcarbazole, or a derivative thereof, a polyarylene derivative having an aromatic amine in the side chain, or the main chain, Using polymers containing aromatic amines such as arylamine derivatives and triphenyldiamine derivatives, these materials are dissolved or dispersed in a solvent, and various coating methods using a spin coater, ink jet methods, nozzle printing methods, It is formed using a relief printing method, a slit coating method, or a bar coating method.

In the step of forming the electron injection layer 107, a mask pattern having a smaller area than that of the organic light emitting layer 106 is used, and depending on the material of the electron injection layer 107, a resistance overheating method, an electron beam evaporation method, a reactive evaporation method, an ion plating method. The electron injection layer 107 is formed using a sputtering method or the like.
In the present embodiment, the electron injection layer 107 forming step is performed as a step after the organic light emitting layer 106 forming step.

After the light emitting medium layer 108 is formed by the above-described light emitting medium layer forming process, a second electrode forming process is performed in which the second electrode 109 is formed on the substrate 101 and the light emitting medium layer 108. That is, the method for manufacturing the organic EL element 100 includes a second electrode forming step. In the second electrode forming step, the second electrode 109 is formed by a resistance heating vapor deposition method, an electron beam vapor deposition method, a reactive vapor deposition method, an ion plating method, a sputtering method, depending on the material of the second electrode 109. It is possible to use a dry film forming method such as. After forming the second electrode 109, the above-described sealing body is formed, and the manufacture of the organic EL element 100 is completed.

(Effects of the first embodiment)
Hereinafter, effects of the first embodiment will be described. In the organic EL element 100 and the manufacturing method thereof according to the present embodiment, when the film thickness of the organic light emitting layer 106 increases toward the partition wall 103 based on the film thickness of the organic light emitting layer 106 at the center of the pixel, When the thickness of the injection layer 107 is increased and conversely reduced, the electron injection layer 107 is also reduced, and the electron injection property can be adjusted between a thick portion and a thin portion. For this reason, in the light emitting medium layer 108 included in the organic EL element 100, it is possible to suppress luminance unevenness and luminance reduction in a portion thicker than the center film thickness of the pixel of the organic light emitting layer 106 or a thin portion. As a result, it is possible to provide an organic EL element 100 and a method for manufacturing the same that can suppress unevenness in light emission and a decrease in luminance occurring in a pixel.

(Modification)
Hereinafter, modifications of the first embodiment will be listed.
(1) In the organic EL element 100 of the present embodiment, the light emitting medium layer 108 is configured to include the hole injection layer 104, the organic light emitting layer 106, and the interlayer layer 105, but is not limited thereto. However, the structure of the light emitting medium layer 108 may not include the interlayer layer 105.
(2) In the manufacturing method of the organic EL element 100 of the present embodiment, the light emitting medium layer forming step includes the interlayer layer 105 forming step of forming the interlayer layer 105, but is not limited thereto. The step of forming the light emitting medium layer 106 may not include the step of forming the interlayer layer 105.

(Example)
Hereinafter, referring to FIG. 1 to FIG. 3, using FIG. 4, the organic EL element 100 of the first embodiment described above and two types of organic EL elements of comparative examples are manufactured, and physical properties of both are evaluated. The results will be described. In the following description, the two types of organic EL elements 100 of the first embodiment are referred to as Example 1 and Example 2. Similarly, in the following description, the organic EL elements of two types of comparative examples are referred to as Comparative Example 1 and Comparative Example 2, respectively. Here, in the organic EL elements of Example 1, Example 2, Comparative Example 1, and Comparative Example 2, the color of the organic light emitting layer 106 was all blue.

Example 1
When manufacturing the organic EL element 100 of Example 1, as the substrate 101, the thin film transistor 200 functioning as a switching element provided on the substrate 101, and the first electrode 102 (pixel electrode) formed thereon are provided. An active matrix substrate provided with The size of the active matrix substrate is 200 [mm] × 200 [mm]. Further, the above active matrix substrate has a diagonal of 5 inches and a display having 320 × 240 pixels arranged in the center. Then, an ITO film having a thickness of 150 [nm] was formed on the above active matrix substrate by sputtering, and this was used as the first electrode 102.

Further, the partition wall 103 was formed so as to partition the pixel surrounding the first electrode 102. Here, when forming the partition wall 103, an acrylic photoresist material is first formed on the entire surface of the active matrix substrate with a thickness of 2 [μm], and then the photolithography is performed on the photoresist material. A partition wall 103 having a width of 30 [μm] was formed on the first electrode 102 by the method.

Next, on the first electrode 102 and the partition 103 formed as described above, molybdenum oxide (MoOx) having a thickness of 20 [nm] was formed by sputtering to form the hole injection layer 104. . Then, using the ink in which the polyvinyl carbazole derivative, which is the material of the interlayer layer 105, is dissolved in toluene so that the concentration is 0.5 [%], the above active matrix substrate is set in a printing machine, Printing was performed on the first electrode 102 sandwiched between the insulating layers by a relief printing method in accordance with the line pattern. At this time, 300 [line / inch] anilox roll and photosensitive resin plate were used. As a result, the thickness of the interlayer layer 105 after printing and drying was 20 [nm].

Next, using the organic light-emitting ink in which the polyphenylene vinylene derivative, which is a blue organic light-emitting material, is dissolved in toluene so that its concentration is 1 [%], the above active matrix substrate is set in a printing machine, The organic light emitting layer 106 was printed by a relief printing method in accordance with the line pattern just above the first electrode 102 sandwiched between the insulating layers. At this time, 150 [line / inch] anilox roll 405 and a water developing type photosensitive resin plate were used. As a result, the film thickness of the organic light emitting layer 106 after printing and drying is 60 nm, which is the thinnest at the center of the pixel, and becomes thicker toward the partition wall 103, and is a film at a point in the pixel 10 μm away from the end of the pixel. The thickness was 5 nm thicker than the center film thickness of the pixel, and the film thickness increased from this point to the edge of the pixel.

Next, Ba was formed as the electron injection layer 107 in two portions by vacuum deposition using two types of metal masks. Here, the metal mask includes a first metal mask (FIG. 4a) in which a range within 10 [μm] opens from the end of the pixel toward the center of the pixel, and a first metal mask in which the entire pixel is open. Two masks (not shown) were used. First, using the first metal mask, Ba is formed to 1.2 [nm] in a region from the edge of the pixel to 10 [μm], and then using the second metal mask, Ba is formed to 4.0 [nm] over the entire pixel. Formed.

Further, as the second electrode 109, an aluminum film is formed by a vacuum deposition method using a second metal mask so as to cover the upper surface of the partition wall 103 and the light emitting medium layer 108 and to have a thickness of 150 [nm]. Filmed. Then, a glass plate as a sealing material is placed on the active matrix substrate on which the second electrode 109 is formed as described above so as to cover the entire light emitting region, and then at about 90 [° C.] for about one hour. The adhesive was thermally cured and sealed.

(Example 2)
Up to the step of forming the partition walls, the same steps as those in Example 1 were performed. Next, on the first electrode 102 and the partition wall 103, molybdenum oxide (MoOx) having a thickness of 20 [nm] was formed by sputtering film formation, whereby the hole injection layer 104 was formed. Then, using the ink in which the polyvinyl carbazole derivative, which is the material of the interlayer layer 105, is dissolved in toluene so that the concentration is 0.5 [%], the above active matrix substrate is set in a printing machine, Printing was performed on the first electrode 102 sandwiched between the insulating layers by an inkjet method in accordance with the line pattern. As a result, the thickness of the interlayer layer 105 after printing and drying was 20 [nm].

Next, using the organic light-emitting ink in which the polyphenylene vinylene derivative, which is a blue organic light-emitting material, is dissolved in toluene so that its concentration is 1 [%], the above active matrix substrate is set in a printing machine, An organic light emitting layer 106 was printed by an ink jet method on the first electrode 102 sandwiched between the insulating layers in accordance with the line pattern. as a result,
The film thickness of the organic light emitting layer 106 after printing and drying is 60 [nm], the center of the pixel being the thickest, and becomes thinner toward the partition wall 103, and the film thickness at a point in the pixel 10 μm away from the edge of the pixel is The film thickness was 5 nm thinner than the central film thickness of the pixel, and the film thickness decreased from this point to the edge of the pixel.

Next, Ba was formed as the electron injection layer 107 in two portions by vacuum deposition using two types of metal masks. Here, the metal mask includes a third metal mask (FIG. 4 b) that opens to a distance of ± 5 [μm] from the center of the pixel toward the partition wall, and the second metal that opens the entire pixel. A mask was used. First, using a third metal mask, Ba is formed to 1.2 [nm] in a region from the center of the pixel to 10 [μm], and then using the second metal mask, Ba is 4.0 over the entire pixel. [Nm] was formed.
(Comparative Example 1)
In the organic EL element of Comparative Example 1, the electron injection layer was formed so as to cover the entire organic light emitting layer with a uniform film thickness. Other materials, the thickness of each layer, and the process were the same as in Example 1 described above. Also in Comparative Example 1, the film thickness at a point in the pixel 10 μm away from the edge of the pixel was 5 nm thicker than the center film thickness of the pixel, and the film thickness increased from this point to the edge of the pixel.
(Comparative Example 2)
In the organic EL element of Comparative Example 2, the electron injection layer was formed so as to cover the entire organic light emitting layer with a uniform film thickness. The other materials, the thickness of each layer, and the process were the same as those in Example 2 described above. Also in Comparative Example 2, the film thickness at a point in the pixel 10 μm away from the edge of the pixel was 5 nm thinner than the center film thickness of the pixel, and the film thickness decreased from this point to the edge of the pixel.

(Evaluation of physical properties for Examples and Comparative Examples)
The organic EL elements of Examples 1 and 2 and Comparative Examples 1 and 2 obtained by the above procedure were visually checked with a microscope for luminance and emission state at 7 V driving, at 150 [cd / m ² ]. The driving voltage was measured and compared.
As a result of visual confirmation of the light emission state, in Examples 1 and 2, luminance unevenness and luminance reduction in the pixel were not observed. On the other hand, in Comparative Example 1, the emission intensity is reduced by 10 [%] from the point that the film thickness at the point within the pixel 10 μm away from the edge of the pixel is 5 nm thicker than the central film thickness of the pixel. Since the film thickness at a point within the pixel 10 μm away from the edge of the pixel is 5 nm thinner than the central film thickness of the pixel, the emission intensity increased by 10%, and luminance unevenness was observed.
Moreover, from the comparison result of the brightness | luminance shown in Table 1, and Example 1, the brightness | luminance of 30% improved compared with the comparative example 1, and the drive voltage at 150 [cd / m < ² >] is 0.5V low. It became voltage. In Example 2, the luminance was improved by 30% compared to Comparative Example 2, and the driving voltage at 150 [cd / m ² ] was reduced by 0.7V. As a result of the above, it was possible not only to suppress luminance unevenness and low luminance by implementing the present invention, but also to obtain a result that the luminance was improved and the driving voltage was lowered.

100 ... Organic EL element 101 ... Substrate (support)
DESCRIPTION OF SYMBOLS 102 ... 1st electrode 103 ... Partition 104 ... Hole transport layer 105 ... Interlayer layer 106 ... Organic light emitting layer 107 ... Electron injection layer 108 ... Light emitting medium layer 109- ..Second electrode (cathode)
200 ... Thin film transistor (TFT)
201 ... pixel electrode 202 ... support 203 ... active layer 204 ... gate insulating film 205 ... gate electrode 206 ... source electrode 207 ... drain electrode 208 ... scanning line 209 ... Insulating film 210 ... Substrate with TFT 211 ... Partition 300 ... Letterpress printing device 301 ... Ink tank 302 ... Ink chamber 303 ... Anilox roll 304 ... Ink layer 305 .... Letter 306 ... Plate cylinder 307 ... Printed substrate 308 ... Stage

Claims (7)

  A substrate, a first electrode formed on the substrate, a partition wall formed on the substrate and surrounding the periphery of the first electrode, and formed on the first electrode in the partition wall constitute a pixel. An organic EL element comprising a light emitting medium layer, and the partition and a second electrode formed on the light emitting medium layer, wherein the light emitting medium layer is arranged from the partition to the center of the pixel except for an electron injection layer. An organic EL element, wherein at least one electron injection / injection layer having a non-uniform film thickness is formed on a light-emitting medium layer whose film thickness is decreasing or increasing as it approaches.   2. The organic EL device according to claim 1, wherein the light emitting medium layer includes a hole injection layer formed under the organic light emitting layer.   The organic EL device according to claim 1, wherein the electron injection layer is formed using a compound of an alkali metal and an alkaline earth metal.   The organic EL device according to claim 1, wherein the electron injection layer is formed using an organic substance.   When the light emission intensity of the organic light emitting layer is reduced on the partition side from the center of the pixel, the thickness of the electron injection layer is made uniform from the center of the pixel to the area where the light emission intensity is reduced by 10% and the light emission intensity is reduced by 10%. When the thickness of the electron injection layer on the partition wall side is increased from the center of the pixel and the emission intensity of the organic light emitting layer increases on the partition wall side from the center of the pixel, the thickness of the electron injection layer from the center of the pixel to the region where the emission intensity increases by 10%. The organic EL according to any one of claims 1 to 4, wherein the thickness of the electron injection layer on the partition wall side is reduced from a region where the thickness is uniform and the emission intensity increases by 10%. element.   When the light emitting film thickness of the organic light emitting layer is thicker on the partition side than the center of the pixel, the thickness of the electron injection layer is made uniform from the center film thickness of the pixel to the region where the film thickness is 5 nm thick, and the film thickness is from the center. When the thickness of the electron injection layer on the partition wall side is increased from the region where the thickness is 5 nm or more, and the emission intensity of the organic light emitting layer is increased on the partition side from the center of the pixel, electrons from the center of the pixel to the region where the film thickness is 5 nm thinner. 5. The electron injection layer on the partition wall side is made thinner from a region where the thickness of the injection layer is made uniform and the film thickness is made thinner by 5 nm or more. The described organic EL element.   It is a manufacturing method of the organic EL element which manufactures the organic EL element as described in any one of Claims 1-6, Comprising: At least one layer among the layers contained in the said light emission medium layer is wet process. The manufacturing method of the organic EL element characterized by forming using a method.