JP2013073842A - Organic el display and organic el display manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve efficiency and a life of a blue light-emitting layer.SOLUTION: The display comprises: a partition wall 3 blocking a substrate 1 into red, green and blue pixels; a pixel electrode 2 provided on the substrate of each pixel; a first hole transport layer 4 provided on the pixel electrode of each pixel; a read light emitting layer 5 provided on the first hole transport layer 5 of the red pixel; a green light emitting layer 6 provided on the first hole transport layer 4 of the green pixel; a first blue light emitting layer 7 provided on the first hole transport layer 4 of the blue pixel; a first electron transport layer 8 provided on the red light emitting layer 5, the green light emitting layer 6 and the first blue light emitting layer 7; a charge generation layer 9 provided on the first electron transport layer 8; a second hole transport layer 10 provided on the load generation layer 9 of the blue pixel; a second blue light emitting layer 11 provided on the second hole transport layer 10; a second electron transport layer 12 provided on the charge generation layers 9 of the red and green pixels and on the second blue light emitting layer 11 of the blue pixel; and a counter electrode 13 provided on the second electron transport layer 12.

Description

  The present invention relates to an organic EL display and a method for manufacturing the organic EL display.

  An organic EL (electroluminescence) element includes a pair of electrodes and a light emitting layer containing an organic compound provided between the electrodes (hereinafter referred to as an organic light emitting layer). When a voltage is applied to the organic EL element, holes are injected from the anode and electrons are injected from the cathode, and these holes and electrons combine in the organic light emitting layer to emit light (see Patent Document 1).

The material for forming the organic light emitting layer and the electrode is formed into a thin film by a vacuum deposition method or the like, and is patterned using a fine pattern mask (hereinafter referred to as a fine metal mask).
However, since a fine metal mask is used in this method, there is a problem that patterning accuracy is less likely to occur as the substrate becomes larger. In addition, since the film is formed in a vacuum, there is a problem that the throughput is poor.

  Therefore, recently, a method of forming a thin film by a wet coating method, in which a polymer material or a low molecular material of the organic light emitting layer is dissolved in a solvent to form a coating liquid (ink), has been tried. There are spin coating methods, bar coating methods, slit coating methods, dip coating methods, etc. as the wet coating method for forming a thin film, but in order to perform patterning with high definition or separate into three colors of RGB These wet coating methods are difficult, and it is considered that thin film formation by a printing method, which is good at coating and patterning, is most effective.

  As a method for printing this organic luminescent ink, an offset printing method using a rubber blanket having elasticity (see Patent Document 2), a relief printing method using a rubber plate or a resin plate having elasticity (see Patent Document 3), Furthermore, an inkjet method (see Patent Document 4), a nozzle printing method, and the like have been proposed.

JP 2010-192472 A JP 2001-93668 A JP 2001-155858 A JP 2002-305077 A

A normal organic EL display includes one organic light emitting layer. Naturally, organic EL displays are required to emit light with high brightness, high efficiency, and long life.
In the organic EL display, if the lifetime of the blue secondary pixel is shorter than the lifetime of the red secondary pixel and the green secondary pixel, there is a problem that only the blue color becomes dark and reddish when the display is driven.

The red organic light-emitting material and the green organic light-emitting material generally use phosphorescent materials, and can emit light with high efficiency and long life even at high luminance.
However, since phosphorescent materials are currently poor in color purity in blue organic light emitting materials, fluorescent materials are generally used, and their efficiency and lifetime are low compared to red organic light emitting materials and green organic light emitting materials.
Also, in the process, there is a problem that patterning accuracy is hardly obtained by using a fine metal mask.
An object of the present invention is to improve the efficiency and lifetime of a blue light emitting layer.

  In order to solve the above problems, an organic EL display is composed of a substrate, a resin composition, a partition partitioning the substrate into red, green, and blue pixels, and pixels provided on the substrate of each pixel. An electrode, a first hole transport layer provided on the pixel electrode of each pixel, a red light-emitting layer provided on the first hole transport layer of the red pixel and emitting light when energized, and a first positive electrode of the green pixel. A green light-emitting layer that is provided on the hole transport layer and emits light when energized; a first blue light-emitting layer that is provided on the first hole transport layer of the blue pixel and emits light when energized; a red light-emitting layer; a green light-emitting layer And a first electron transport layer provided on the first blue light-emitting layer, a charge generation layer provided on the first electron transport layer, and a second hole provided on the charge generation layer of the blue pixel. A second blue light emitting layer that is provided on the transport layer and the second hole transport layer and emits light when energized. Layer, a second electron transport layer provided on the charge generation layer of the red pixel and the green pixel, and a second blue light emitting layer of the blue pixel, and a pixel electrode provided on the second electron transport layer. And a counter electrode that is energized between them.

That is, the first hole transport layer, the charge generation layer, the first electron transport layer, and the second electron transport layer are provided on the entire surface of the light emitting display area, and the red pixel is provided with one red light emitting layer, and the green pixel. Is provided with one green light emitting layer, and the blue pixel is provided with a first blue light emitting layer, a second hole transport layer, and a second blue light emitting layer.
The red organic light emitting layer and the green organic light emitting layer are characterized by being made of a phosphorescent organic compound.

  The organic EL display manufacturing method includes a step of partitioning a substrate into red, green, and blue pixels by a partition made of a resin composition, a step of providing a pixel electrode on the substrate of each pixel, and each pixel. A step of providing a first hole transport layer on the pixel electrode, a step of providing a red light-emitting layer that emits light when energized on the first hole transport layer of the red pixel, and a step of providing on the first hole transport layer of the green pixel A step of providing a green light-emitting layer that emits light by energization, a step of providing a first blue light-emitting layer that emits light by energization on the first hole transport layer of the blue pixel, a red light-emitting layer, a green light-emitting layer, and a first A step of providing a first electron transport layer on the blue light-emitting layer, a step of providing a charge generation layer on the first electron transport layer, a step of providing a second hole transport layer on the charge generation layer of the blue pixel, A second blue light emitting on the two-hole transport layer when energized. A step of providing a layer; a step of providing a second electron transport layer on the charge generation layer of the red pixel and the green pixel; and a second blue light emitting layer of the blue pixel; and a pixel electrode on the second electron transport layer. And a step of providing a counter electrode to be energized between them.

  According to the present invention, by providing the first blue light emitting layer and the second blue light emitting layer in the blue pixel, the efficiency and life of the blue light emitting layer can be improved.

It is a schematic diagram of the organic EL display panel cross section in an organic EL apparatus. It is a schematic diagram of the nozzle printing apparatus in an organic EL apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Here, a case where a passive matrix type organic EL display panel is formed will be described as an example. However, this embodiment is not limited to this.
FIG. 1 is a schematic view showing a cross section of an organic EL display panel.
The organic EL element in the organic EL display panel is formed on the translucent substrate 1. As the translucent substrate 1, a glass substrate, a plastic film, or a sheet can be used. If a plastic film is used, a polymer EL element can be produced by winding, and a display panel can be provided at a low cost. As the plastic, for example, polyethylene terephthalate, polypropylene, cycloolefin polymer, polyamide, polyethersulfone, polymethyl methacrylate, polycarbonate and the like can be used. In addition, these films include a barrier layer made of a metal oxide such as silicon oxide that exhibits water vapor barrier property and oxygen barrier property, nitride such as silicon nitride, polyvinylidene chloride, polyvinyl chloride, saponified ethylene-vinyl acetate copolymer. Is provided as necessary.

  On the translucent substrate, a pixel electrode 2 patterned as an anode is provided. As the material of the pixel electrode 2, transparent electrode materials such as ITO (indium tin composite oxide), IZO (indium zinc composite oxide), tin oxide, zinc oxide, indium oxide, and aluminum oxide composite oxide can be used. ITO is preferred because of its low resistance, solvent resistance, transparency, and the like. ITO is formed on the translucent substrate by sputtering, and is patterned by photolithography to form line-shaped pixel electrodes 2.

  After the line-shaped pixel electrode 2 is formed, the partition wall 3 is formed by a photolithography method using a photosensitive material between adjacent pixel electrodes. More specifically, the method includes at least a step of applying a photosensitive resin composition to a substrate and a step of pattern exposure and development to form a partition pattern.

As the photosensitive material for forming the partition walls 3, a positive resist is used in the present embodiment, but the present invention is not limited to this, and a negative resist or other resin may be patterned by dry etching or the like. The positive resist may be a commercially available one, but needs to have insulating properties. If the partition does not have sufficient insulation, current flows through the partition to the adjacent pixel electrode, and display defects such as abnormal light emission and current leakage occur. Specific examples of the photosensitive material include, but are not limited to, polyimide, acrylic resin, novolac resin, and fluorene resin. Further, for the purpose of improving the display quality of the organic EL element, a light shielding material may be included in the photosensitive material.
The photosensitive resin that forms the partition walls 3 is applied using a known coating method such as a spin coater, bar coater, roll coater, die coater, or gravure coater. Next, in the step of pattern exposure and development to form the partition wall pattern, the partition wall pattern can be formed by a conventionally known exposure and development method.

  Proximity exposure, which is also used in color filters, is preferable as a pattern exposure method from the viewpoint of productivity and cost, but is not limited thereto. Here, in the case of proximity exposure, a photomask is used for patterning the partition walls, but the photomask needs to be designed so that the partition walls have the desired shape. In many cases, the partition shape required is obtained by producing a photomask having a pattern corresponding to the difference between positive and negative with almost the same pattern as the partition. In the case where the barrier rib is formed using a positive resist, the photomask is designed so that a portion with the barrier is shielded from light. After patterning the barrier ribs by exposure and development, the patterned photoresist resin is cured by heating in a baking step to form barrier ribs. The firing temperature at this time is preferably 180 ° C. or higher. If the firing temperature is lower than this, sufficient resistance and stability cannot be obtained.

  In addition to the exposure and development methods described above, the partition walls 3 can be patterned by a printing method or the like. For example, in the case of the reverse offset printing method, first, a resin for forming a partition is formed on a blanket with a solid, and then an unnecessary portion of the pattern is removed by transferring it to a printing plate. Finally, the partition pattern is formed by transferring the pattern remaining on the blanket in alignment with the substrate to be printed. Moreover, a hardening process is performed by baking after the pattern formation of a partition. Also in the case of the reverse offset printing method, examples of the resin component forming the partition include, but are not limited to, polyimide, acrylic resin, novolac resin, and fluorene resin.

The partition wall in the present invention preferably has a thickness in the range of 0.5 μm to 5.0 μm. If the partition wall is too thin, it may not be possible to prevent the occurrence of leakage current between adjacent pixels via the hole transport layer and the effect of preventing a short circuit.
In the organic EL display panel, when the partition 3 is provided between the pixel electrodes, the cathode layer is formed by crossing the partition directly and across. When the cathode layer is formed in such a manner as to straddle the partition wall, if the partition wall 3 is too high, the cathode layer is disconnected, resulting in a display defect. If the height of the partition wall 3 exceeds 5.0 μm, it is not preferable because the cathode is easily disconnected even if the partition wall has a forward tapered cross section.

  As described above, the first hole transport layer 4 is formed after the partition wall 3 is formed. Examples of the hole transport material forming the first hole transport layer 4 include metal phthalocyanines such as copper phthalocyanine and tetra (t-butyl) copper phthalocyanine, and metal-free phthalocyanines, quinacridone compounds, 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane, N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1′-biphenyl-4,4′-diamine, N, N Aromatic amine low molecular hole injection and transport materials such as' -di (1-naphthyl) -N, N'-diphenyl-1,1'-biphenyl-4,4'-diamine, and poly (para-phenylene vinylene) ), Polymer hole transport materials such as polyaniline, polythiophene oligomer materials, and other known hole transport materials.

As a method for forming the first hole transport layer 4, a known film forming method such as a nozzle printing method, a spin coating method, a slit coating method, an ink jet method, and a relief printing method can be used.
After the formation of the first hole transport layer 4, a red organic light emitting layer 5, a green organic light emitting layer 6, and a first blue organic light emitting layer 7 are formed. The red organic light emitting layer 5, the green organic light emitting layer 6, and the first blue organic light emitting layer 7 are layers that emit light when a current is passed therethrough, and the red organic light emitting layer 5, the green organic light emitting layer 6, and the first blue organic light emitting layer. The organic light-emitting material forming the layer 7 may be any material generally used as an organic light-emitting material. Coumarin-based, perylene-based, pyran-based, anthrone-based, porphyrene-based, quinacridone-based, N, N′-dialkyl substitution Known phosphorescent low molecular weight materials that can emit light from a singlet state, such as quinacridone-based, naphthalimide-based, N, N′-diaryl-substituted pyrrolopyrrole-based materials, and known phosphorescence capable of emitting from a triplet state of a rare earth metal complex system Low molecular weight materials.

  These organic light emitting materials are dissolved in a solvent or stably dispersed to form an organic light emitting ink. 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. Among these, aromatic organic solvents such as toluene, xylene, and anisole are preferable from the viewpoint of solubility of the organic light emitting material. Moreover, surfactant, antioxidant, a viscosity modifier, a ultraviolet absorber, etc. may be added to organic luminescent ink as needed.

As a method for forming the organic light emitting layer, it is possible to form a pattern by a nozzle printing method, a slit coating method, an ink jet method, a relief printing method, an intaglio offset printing method, a relief printing reverse offset printing method, and the like.
After forming the red organic light emitting layer 5, the green organic light emitting layer 6, and the first blue organic light emitting layer 7, the first electron transport layer 8 is formed. The material of the first electron transport layer 8 may be any material generally used as an electron transport material, and examples thereof include low molecular materials such as triazole, oxazole, oxadiazole, silole, and boron. In addition, film formation by vacuum deposition is possible.

After the formation of the first electron transport layer 8, the charge generation layer 9 is formed. The material of the charge generation layer 9 is preferably a transition metal oxide. Among the transition metal oxides, vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten ( W), manganese (Mn), technetium (Tc), oxides such as rhenium (Re) are preferable, and WO3 is more preferable. The film can be formed by vacuum evaporation.
After the formation of the charge generation layer 9, the second hole transport layer 10 is formed. As the material of the second hole transport layer 10, the same material as that of the first hole transport layer 4 described above is used, but is not limited thereto.

As a method for forming the second hole transport layer 10, a known film forming method such as a nozzle printing method, a slit coating method, an ink jet method, and a relief printing method can be used.
After the formation of the second hole transport layer 10, the second blue organic light emitting layer 11 is formed. As the material of the second blue organic light emitting layer 11, the same material as that of the first blue organic light emitting layer described above is used, but is not limited thereto.

As a method for forming the second blue organic light-emitting layer 11, a coating type material can be patterned by a nozzle printing method, a slit coating method, an ink jet method, a relief printing method, an intaglio offset printing method, a relief reverse printing method, etc. It is.
After the formation of the second blue organic light emitting layer 11, the second electron transport layer 12 is formed. As the material of the second electron transport layer 12, the same material as the first electron transport layer 8 described above is used, but the material is not limited to this. The film can be formed by vacuum evaporation.

  After the formation of the second electron transport layer 12, the counter electrode 13 is formed. As the material of the counter electrode 13, a material according to the light emission characteristics of the organic light emitting layer can be used. For example, a simple metal such as lithium, magnesium, calcium, ytterbium, or aluminum, or a stable metal such as gold or silver can be used. An alloy etc. are mentioned. Alternatively, a conductive oxide such as indium, zinc, or tin can be used. As a formation method of a cathode layer, the formation method by the vacuum evaporation method using a mask is mentioned.

In the organic EL display panel of the present embodiment, the hole transport layer, the organic light emitting layer, and the electron transport layer are laminated from the anode layer side between the pixel electrode as the anode and the cathode layer. A layered structure in which layers such as a hole blocking layer and an electron injection layer are selected as necessary in addition to the hole transport layer and the organic light emitting layer between the cathode layers can be employed. Moreover, when forming these layers, the formation method similar to a positive hole transport layer, a light emitting layer, and a cathode layer can be used.
Finally, in order to protect these organic EL constituents from external oxygen and moisture, the organic EL display panel can be obtained by hermetically sealing with a glass cap 14 and an adhesive 15. Moreover, when the translucent board | substrate 1 has flexibility, you may seal using a sealing agent and a flexible film.

Example 1
Example 1 will be described.
An ITO (indium-tin oxide) thin film is formed on a 1.8 inch diagonal glass substrate by sputtering, and the ITO film is patterned by photolithography and etching with an acid solution. Formed. The line pattern of the pixel electrode 2 is a pattern in which about 270 lines are formed in a line of about 32 mm square with a line width of 90 μm and a space of 30 μm.

  Next, the partition 3 was formed as follows so as to have a line shape parallel to the pixel electrode 2. On the glass substrate as the translucent substrate 1 on which the pixel electrode 2 was formed, LC100 manufactured by AZ Electronic Materials was spin-coated as a positive photosensitive resist. The spin coating condition was rotated at 150 rpm for 5 seconds and then at 500 rpm for 20 seconds, so that the height of the partition wall was 2.0 μm. The photosensitive material applied to the entire surface was exposed and developed by a photolithography method to cover the space between the pixel electrodes 2 and to form partition walls 3 having a lattice pattern to form pixels. Thereafter, the partition walls 3 were baked in an oven at 230 ° C. for 30 minutes.

  Next, as a hole transport ink to be the first hole transport layer 4, 40 ml of BYTRON CH-8000, 40 ml of ultrapure water, and 20 ml (20% by volume) of 1-propanol were mixed and prepared. did. In addition, as a pretreatment for the substrate before applying the hole transport ink, UV irradiation was performed for 3 minutes with a UV / O3 cleaning device manufactured by Oak Manufacturing. As shown in FIG. 2, using a nozzle printing device 4a, ink of a hole transport material is applied onto the pixel electrode 2 by a nozzle printing method using the nozzle printing device 4a to form a hole transport layer. The nozzle printing apparatus 4a includes an ink tank 2a that stores organic light-emitting ink, and an ink nozzle 3a that discharges a liquid column of ink. An ink liquid column is ejected from the ink nozzle 3 a toward the surface of the pixel electrode 2. The ink adhering to the pixel electrode 2 is averaged within the area partitioned by the partition 3 because of its low viscosity. Thereafter, it is dried and fixed.

The nozzle printing device 4a may be a multi-nozzle including at least one or more nozzles 3a. Productivity can be improved by using multiple nozzles.
Thereafter, the substrate was placed in a 30 ° C. vacuum drying oven and dried under reduced pressure. At this time, it became 10 kPa in about 40 seconds, and after 0.5 minutes it became 0.5 kPa. Then, the pressure was returned to atmospheric pressure, the vacuum drying step was finished, and a hole transport layer was formed. The film thickness of the hole transport layer at this time was 50 nm. The coating state was confirmed with respect to the formed positive hole transport layer.

Next, an organic light emitting layer was formed by a nozzle printing method in accordance with the line pattern just above the pixel electrode 2 sandwiched between the partition walls 3.
The host material of the red organic light emitting layer 5 is 2,2 ′, 2 ″-(1,3,5-benzenetriyl) tris (1-phenyl-1H-benzimidazole) (TPBi), and the doped material is 2 3,7,8,12,13,17,18-octaethyl-21H, 23H-polyphyllin platinum 2 (PtOEP), the weight ratio becomes 1% at TPBi / PtOEP = 0.90 / 0.10 Thus, the organic light emitting ink dissolved in toluene was used, and the thickness of the dried organic light emitting layer was 50 nm at the center of the pixel.

  The host material of the green organic light emitting layer 6 is TPBi, and the doping material is tris (2- (p-tolyl) pyridine) iridium III (Ir (mppy) 3), and the weight ratio is TPBi / Ir (mppy) 3. = 0.94 / 0.06 An organic light-emitting ink dissolved in toluene so as to have a concentration of 1% was used. At this time, the thickness of the dried organic light emitting layer was 50 nm at the center of the pixel.

For the blue organic light emitting layer 7, an organic light emitting ink in which a diphenylanthracene derivative was dissolved in toluene to a concentration of 1% was used. At this time, the thickness of the dried organic light emitting layer was 50 nm at the center of the pixel.
The concentration of the organic light emitting material in the ink may be in the range of 0.1 wt% to 5.0 wt%, and more preferably 0.5 wt% to 1.5 wt%. Thus, by setting the concentration to 0.1 wt% or more and 5.0 wt% or less, the film thickness at the time of nozzle print application does not become too large, and the pattern accuracy at the time of nozzle print application can be maintained. Note that the weight of the organic light-emitting material in the above ratio represents the combined weight of the host material and the dopant material.

Next, the first electron transport layer 8 was formed by depositing Alq3, which is an electron transport material, by 30 nm mask deposition by resistance heating vapor deposition.
Next, the charge generation layer 9 was formed by depositing WO3, which is a charge generation material, by a resistance heating vapor deposition method using a 20 nm mask.
Next, 40 ml of Vitron CH-8000, 40 ml of ultrapure water, and 20 ml (20% by volume) of 1-propanol are mixed on the blue secondary pixel as hole transport ink to be the second hole transport layer 10. Then, the ink was prepared and used as an ink. In addition, as a pretreatment for the substrate before applying the hole transport ink, UV irradiation was performed for 3 minutes with a UV / O3 cleaning device manufactured by Oak Manufacturing. The hole transport layer was applied by a nozzle printing method. Thereafter, the substrate was placed in a vacuum drying furnace at 30 ° C., and vacuum drying was performed. At this time, it became 10 kPa in about 40 seconds, and after reaching 0.5 kPa after 5 minutes, the pressure was returned to atmospheric pressure to form a hole transport layer. The film thickness of the hole transport layer at this time was 50 nm. The coating state was confirmed with respect to the formed positive hole transport layer.

  Next, as the second blue organic light-emitting layer 11, an organic light-emitting ink in which a diphenylanthracene derivative of a blue organic light-emitting material is dissolved in toluene so as to have a concentration of 1% is used. On top of this, the organic light emitting layer was patterned by a nozzle printing method in accordance with the line pattern. At this time, the thickness of the dried organic light emitting layer was 50 nm at the center of the pixel.

Next, the second electron transport layer 12 was formed by depositing Alq3, which is an electron transport material, by 30 nm mask deposition by resistance heating deposition.
Finally, the counter electrode 13 made of LiF and Al was formed by mask vapor deposition using a resistance heating vapor deposition method in a line pattern orthogonal to the line pattern of the pixel electrode 2. The line pattern of the counter electrode 13 was formed by forming a line width of 90 μm, a space of 30 μm, a LiF layer with a thickness of 0.5 nm, and then forming Al with a thickness of 150 nm. And in order to protect these organic electroluminescent structures from external oxygen and a water | moisture content, it sealed and sealed using the glass cap 14 and the adhesive agent 15, and produced the organic EL element.

The obtained passive organic EL display panel did not have a short circuit between electrodes, was able to light only selected pixels, and obtained a good display device free from uneven light emission. When only the blue secondary pixel was lit, the luminance was 8.0 V and showed 150 cd / m ² . The luminance half time at an initial luminance of 200 cd / m ² was 1500 hours.

In the obtained passive organic EL display panel, when only the red secondary pixel was turned on, the luminance was 150 cd / m ² at 6V. The luminance half time at an initial luminance of 200 cd / m ² was 3000 hours.
When only the green secondary pixel was lit in the obtained passive organic EL display panel, the luminance was 150 cd / m ² at 4V. The luminance half time at an initial luminance of 200 cd / m ² was 5000 hours.

(Comparative Example 1)
In Comparative Example 1, after forming the first electron transport layer 8, without forming the charge generation layer 9, the second hole transport layer 10, the second blue organic light emitting layer 11, and the second electron transport layer 12. The cathode was formed into a film.
The obtained passive organic EL display panel did not have a short circuit between electrodes, was able to light only selected pixels, and obtained a good display device free from uneven light emission. When only the blue secondary pixel was lit, the luminance was 6.0 V and showed 150 cd / m ² . The luminance half time at an initial luminance of 200 cd / m ² was 700 hours.

When only the red secondary pixel was turned on in the obtained passive organic EL display panel, the luminance was 150 V / m ² at 6.5V. The luminance half time at an initial luminance of 200 cd / m ² was 2950 hours.
When only the green secondary pixel was lit in the obtained passive organic EL display panel, the luminance was 4.8 V and 150 cd / m ² . The luminance half time at an initial luminance of 200 cd / m ² was 4870 hours.

1: translucent substrate 2: pixel electrode 3: partition wall 4: first hole transport layer 5: red organic light emitting layer 6: green organic light emitting layer 7: first blue organic light emitting layer 8: first electron transport layer 9: Charge generation layer 10: second hole transport layer 11: second blue organic light emitting layer 12: second electron transport layer 13: counter electrode 14: glass cap 15: adhesive 2a: ink tank 3a: ink nozzle 4a: nozzle print apparatus

Claims (3)

A substrate,
A partition comprising a resin composition and partitioning the substrate into red, green, and blue pixels;
A pixel electrode provided on the substrate of each pixel;
A first hole transport layer provided on the pixel electrode of each pixel;
A red light emitting layer that is provided on the first hole transport layer of the red pixel and emits light when energized;
A green light emitting layer that is provided on the first hole transport layer of the green pixel and emits light when energized;
A first blue light emitting layer that is provided on the first hole transport layer of the blue pixel and emits light when energized;
A first electron transport layer provided on the red light-emitting layer, the green light-emitting layer, and the first blue light-emitting layer;
A charge generation layer provided on the first electron transport layer;
A second hole transport layer provided on the charge generation layer of the blue pixel;
A second blue light emitting layer that is provided on the second hole transport layer and emits light when energized;
A second electron transport layer provided on the charge generation layer of the red pixel and the green pixel, and on the second blue light emitting layer of the blue pixel;
An organic EL display, comprising: a counter electrode provided on the second electron transport layer and energized with the pixel electrode.   2. The organic EL display according to claim 1, wherein the red organic light emitting layer and the green organic light emitting layer are made of a phosphorescent organic compound. A step of partitioning the substrate into red, green, and blue pixels by a partition made of a resin composition;
Providing a pixel electrode on the substrate of each pixel;
Providing a first hole transport layer on the pixel electrode of each pixel;
Providing a red light emitting layer that emits light by energization on the first hole transport layer of the red pixel;
Providing a green light emitting layer that emits light by energization on the first hole transport layer of the green pixel;
Providing a first blue light emitting layer that emits light by energization on the first hole transport layer of a blue pixel;
Providing a first electron transport layer on the red light emitting layer, on the green light emitting layer, and on the first blue light emitting layer;
Providing a charge generation layer on the first electron transport layer;
Providing a second hole transport layer on the charge generation layer of a blue pixel;
Providing a second blue light emitting layer that emits light by energization on the second hole transport layer;
Providing a second electron transport layer on the charge generation layer of a red pixel and a green pixel and on the second blue light emitting layer of a blue pixel;
And a step of providing a counter electrode to be energized between the pixel electrode on the second electron transport layer.

Images