JP2001076881A - Organic light-emitting device and manufacture therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance a display quality by the emitting light, and to restrain the degradation with the lapse of time by forming a barrier rib vicinal surface of a recessed cross-sectional shape in an organic layer of at least one layer. SOLUTION: This organic light-emitting device 10 is formed by laminating a polarizing plate 7, a base board 1, a first electrode 2, an organic layer 3, a second electrode 4 and a sealing film 6 in this order, and at least a barrier rib 5 is formed in a part on the periphery of the organic layer 3 to form one picture element. One layer in at least the organic layer 3 is formed by solidifying a recessed meniscus when injecting an organic layer forming painting liquid. The barrier rib 5 has critical surface tension larger than surface tension at 20 deg.C of the organic layer forming painting liquid injected inside, and this painting liquid is formed of an inorganic material and an organic material such as forming the recessed meniscus by wetting the inside of the barrier rib 5. A difference between the critical surface tension of a material of such a barrier rib 5 and surface tension of the organic layer forming painting liquid is desirably 5 dyne/cm or more (20 deg.C).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an organic light emitting device used as a pixel of a display and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a coating method such as a spin coating method, a dipping method, and a doctor blade method has been used for forming an organic light emitting device by a wet method.
It was very difficult to colorize the pixels by patterning the light emitting layer. However, in recent years, as one solution to this problem, a light-emitting layer is formed by an inkjet method (Japanese Patent Laid-Open No. 10-12377, Appl. Phys. Lett. No. 72, 5).
19, 1998), a method of forming a pattern by a wet method such as a printing method has been proposed.

[0003]

However, when the pixels are colored by the wet method, when the light emitting layers are formed, the light emitting layers of the respective colors are mixed and mixed, or a color having a high energy is not emitted due to the energy transfer. There is a problem that a display phenomenon is deteriorated due to a phenomenon. In order to prevent this phenomenon, a resin black resist (Japanese Unexamined Patent Application Publication No.
0-153967, JP-A-11-40358, JP-A-11-54270) or a partition such as a water- and oil-repellent bank (JP-A-11-87062). A method of surrounding has been proposed.

FIG. 7 shows an example of an organic light emitting device. The organic light emitting device (organic LED medium) 110 includes a polarizing plate 107, a substrate 101, an anode 102, an organic layer 103, and a cathode 104.
Are laminated in this order, and the partition 105 is
3 to form one pixel. After forming the partition wall 105 on the anode 102, the organic layer 103 is coated with a solution or dispersion containing an organic light emitting material and / or an organic charge transporting material (hereinafter referred to as “organic layer forming coating liquid”). It is formed by injecting into the inside. The cathode 104 is formed directly on the organic layer 103 or after forming an organic layer (not shown).
It is formed by vapor deposition or the like.

The organic light-emitting material is usually composed of an organic polymer material or an organic low-molecular material. When a solution or a dispersion of these materials is injected into the inside of the partition wall 105, these liquids do not wet the inside of the partition wall 105. The meniscus of the organic layer 103 becomes convex. In this case, the surface tension γ of the coating liquid for forming an organic layer and the critical surface tension γc of the partition wall 105 are γc <
γ. When a voltage is applied to the organic light emitting device 110 on which the organic layer 103 is formed by solidifying such an organic layer forming coating liquid, the thinnest portion of the organic layer 103, that is,
The interface portion where the organic layer 103 and the partition wall 105 are in contact emits light strongly, and the display quality as a display is degraded. Further, since the electric field is locally concentrated, it may cause deterioration of the organic layer 103.

FIG. 8 shows an organic light emitting device 120 in which a cathode 104 is formed in a relatively flat central portion of an organic layer 103 in order to solve the above problem. In the organic light emitting element 120, since the cathode 104 is formed apart from the partition 105, it is possible to suppress light emission at the interface where the organic layer 103 and the partition 105 are in contact with each other, but this reduces the aperture ratio. Further, when forming the patterned cathode 104 using a shadow mask or the like, the formation of the cathode 104 is limited to the central portion of the organic layer 103, so that the alignment of the shadow mask becomes difficult.

The present invention has been made in view of the above-mentioned problems, and provides an organic light-emitting device which has high display quality by light emission, suppresses deterioration over time, and is easy to manufacture, and a method for manufacturing the same. .

[0008]

According to the present invention, a first electrode, a partition formed on the first electrode and partitioning at least a portion between adjacent pixels, and an organic layer formed inside the partition are provided. An organic light-emitting device having a layer and a second electrode formed on the organic layer, wherein at least one organic layer has a surface in the vicinity of a partition wall having a concave cross-sectional shape. Provided.

That is, the present inventors have paid attention to the degree of “wetting” of the organic layer forming coating liquid with respect to the partition walls, and have made the sectional shape of at least one organic layer concave on the surface near the partition walls. Both the coating liquid for forming an organic layer and the partition walls were intensively studied from the viewpoint of their respective materials. As a result, a method for obtaining an organic light emitting element in which an organic layer is formed by solidifying a concave meniscus when an organic layer forming coating liquid is injected into the inside of the partition wall has been completed. According to the present invention, when an electrode is formed on the surface of an organic layer using an organic light-emitting element and a shadow mask, the local light emission at the interface between the organic layer and the partition wall and the deterioration with time due to the local light emission are suppressed. Thus, a method for manufacturing an organic light-emitting device that facilitates the alignment of the organic light-emitting device has been completed. By using such an organic light emitting element, an organic light emitting display having excellent display quality and a high aperture ratio can be provided.

According to another aspect of the present invention, a partition partitioning at least a part between adjacent pixels is formed on the first electrode, and a solution or dispersion containing an organic light emitting material is injected into the partition. Forming an organic layer, and then forming a second electrode on the organic layer, the critical surface tension of the partition at 20 ° C. A method for manufacturing an organic light-emitting device is provided, wherein the surface tension of the solution or dispersion containing the solution is higher than the surface tension at 20 ° C.

In the present invention, a pixel means a pixel in the case of a monochrome or zone color display, and a sub-pixel in the case of a multi-color or full-color display. Although the shape of the pixel is not particularly limited, a polygonal shape, a circular shape, and an elliptical shape are exemplified. In order to form a uniform film up to the corners of the pixels, it is preferable that the corners of the pixels be concave toward the center when viewed from above.

In the present invention, the meniscus is a free surface of the coating liquid for forming an organic layer in the vicinity of the partition wall, and when the coating liquid for forming an organic layer wets the partition wall, that is, the meniscus relative to the partition wall of the coating liquid for forming an organic layer. When the adhesive force is large, a concave meniscus is formed, and when the organic layer forming coating liquid does not wet the partition walls, that is, when the adhesive force of the organic layer forming coating liquid to the partition walls is small, a convex meniscus is formed. It becomes a meniscus.

The critical surface tension in the present invention means the "Zisman critical surface tension" which defines the degree of "wetting" of a liquid on the surface of a solid. That is, polar organic liquids, saturated hydrocarbons, water, etc. having various surface tensions are dropped on the surface of most solids such as organic polymers and organic compounds having a low energy surface, and their contact angles θ Are measured, and these cos θ are plotted against the surface tension γ [dyne / cm 2] of each liquid, and the surface tension value γc at the point where the obtained approximate straight line intersects the horizontal line at the contact angle θ = 0 ° dyne / cm 2] is the critical surface tension in the present invention. The surface tension of the coating liquid for forming an organic layer in the present invention is a surface tension value γ expressed as a work [erg] for the liquid to form a surface having a unit area [cm ² ].
[Dyne / cm].

If the difference between the critical surface tension of the inner wall surface of the partition wall at 20 ° C. and the surface tension of the coating liquid for forming an organic layer at 20 ° C. is 5 dyne / cm or more, a concave shape sufficient to solve the above-mentioned problem is obtained. Can be formed on the surface near the inside of the partition wall. The partition walls are further formed by superimposing an upper partition wall distal to the first electrode, and the critical surface tension of the inner wall surface of the upper partition wall is configured to be smaller than the surface tension of the organic layer forming coating liquid, When the coating liquid for forming an organic layer is injected into the inside of the partition, the inner wall surface of the upper partition becomes water-repellent or oil-repellent to the coating liquid for forming an organic layer. Since the inside of the partition is not wetted, the coating liquid for forming an organic layer does not extend along the partition to the adjacent pixels, and a short circuit between the pixels can be prevented. Further, since contamination of the adjacent pixels by the organic layer forming coating liquid is prevented, problems such as color mixing can be avoided. Also,
The difference between the critical surface tension of the inner wall surface of the upper partition wall at 20 ° C. and the surface tension of the coating solution for forming an organic layer at 20 ° C. is 5dy.
When it is at least ne / cm, the coating liquid for forming an organic layer does not extend along the partition and over adjacent pixels, and the effect of the upper partition can be sufficiently exhibited.

By making the critical surface tension of the first electrode at 20 ° C. higher than the surface tension of the organic layer forming coating liquid at 20 ° C., the wettability of the organic layer forming coating liquid with respect to the electrode is improved. Then, the coating liquid for forming an organic layer can be filled up to the inner corners and corners of the partition walls. The difference between the critical surface tension of the first electrode at 20 ° C. and the surface tension of the organic layer forming coating solution at 20 ° C. is 5 dyne / cm.
With the above, the wettability of the coating liquid for forming an organic layer on the electrode is improved, and a more effective organic layer can be formed. As a result, the adhesion between the electrode and the organic layer is improved during the formation of the organic layer, and the efficiency of charge injection from the electrode to the organic layer is improved.

As a method of injecting the organic layer forming coating liquid into the inside of the partition wall, a spin coating method, a printing method, an ink jet method of discharging the organic layer forming coating liquid from an ink jet head, or a nozzle or needle for forming the organic layer forming liquid. A known method such as a nozzle injection method for discharging a coating liquid can be employed.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS.
The embodiments of the organic light emitting device and the method of manufacturing the same according to the present invention will be described, but the present invention is not limited by the embodiments. FIG. 1 shows a basic structure of the organic light emitting device of the present invention. In FIG. 1, an organic light emitting device 10 includes a polarizing plate 7,
Substrate 1, first electrode 2 (anode), organic layer 3, second electrode 4
(Cathode) and the sealing film 6 are laminated in this order, and at least the partition wall 5 is formed at a part around the organic layer 3.
To form one pixel. At least organic layer 3
One of the layers is formed by solidifying a concave meniscus when the coating liquid for forming an organic layer is injected. As the substrate 1, a quartz substrate, a glass substrate, a plastic substrate, or the like is used.

The first electrode 2 and the second electrode 4 are electrode pairs forming positive and negative electrodes. When the substrate 1 and the first electrode 2 are transparent, light emitted from the organic layer 3 is emitted from the substrate 1 side. Since the light is emitted, in order to enhance the luminous efficiency, it is preferable that the second electrode 4 is a reflective electrode, or that the second electrode 4 has a reflective film on the side not adjacent to the organic layer 3. Conversely, the second electrode 4 can be made of a transparent material, and light emitted from the organic layer 3 can be emitted from the second electrode 4 side. In this case, it is preferable that the first electrode 2 is a reflective electrode, the substrate 1 is a reflective substrate, or a reflective film is provided between the first electrode 2 and the substrate 1.

As the transparent electrode, CuI, ITO, Sn
A transparent electrode such as O ₂ , ZnO, CuAlO ₂ is used. Further, as the reflective electrode, a metal such as aluminum and calcium, an alloy such as magnesium-silver and lithium-aluminum, a laminated film of metals such as magnesium / silver,
A laminated film of an insulator such as lithium fluoride / aluminum and a metal is used. The deflection plate 7 is provided outside the substrate 1 in order to obtain a good contrast in the display. The sealing film 6 (or the sealing substrate) is provided to prevent the damage of the second electrode 4 or the deterioration of the organic layer and the electrode.

The partition walls 5 have a critical surface tension greater than the surface tension at 20 ° C. of the coating liquid for forming an organic layer injected into the inside of the partition walls 5, and the coating liquid for forming an organic layer wets the inside of the partition walls 5. As a result, it is formed of an inorganic material or an organic material such that a concave meniscus is formed. Therefore, the material of the partition wall 5 is selected in relation to the surface tension of the coating liquid for forming an organic layer. Preferred materials for forming the partition walls 5 are listed below. The values in parentheses indicate the critical surface tension value γc [dyne / cm 2] of the barrier rib material at 20 ° C.

A preferable material for forming the partition walls 5 is, for example, poly (propylene hexafluoride) (γc = 16dy).
ne / cm), polytetrafluoroethylene (γc = 18 dyne / cm)
), Polytetrafluoroethylene (γc = 22 dyne / cm),
Polyvinylidene fluoride (γc = 25 dyne / cm), polyethylene (γc31 dyne / cm), polybutadiene (γc =
31dyne / cm), polystyrene (γc = 33dyne / cm)
), Polyethyl acrylate (γc = 35 dyne / cm),
Polyvinyl alcohol (γc = 37 dyne / cm 2), chloroprene (γc = 38 dyne / cm 2), polyvinyl chloride (γc
= 39 dyne / cm), polymethyl acrylate (γc = 39)
dyne / cm), polyvinylidene chloride (γc = 40 dyne / cm)
), 6 nylon (γc = 42 dyne / cm), 6-6 nylon (γc = 42 dyne / cm), 7-7 nylon (γc =
43dyne / cm), polyethylene terephthalate (γc =
43dyne / cm), polyhexamethylene adibamide (γc
= 46 dyne / cm 2), glass (γc = 55 dyne / cm 2) and the like. In addition, a material obtained by mixing KBM7103 (γc = 20 dyne / cm 2) manufactured by Shin-Etsu Chemical Co., Ltd. in a positive resist is also a preferred material.

Alternatively, the value of the critical surface tension γc of the surface of the partition 5 may be controlled by performing plasma treatment, UV treatment, gas treatment, etc. after forming the partition 5 using these materials. The partition walls 5 are formed by using the above-described materials or by performing the above-described processes.
Although the partition wall 5 is formed, in order to form a more effective concave meniscus, the difference between the critical surface tension γc of the material of the partition wall 5 and the surface tension γ of the coating liquid for forming an organic layer, which will be described later, becomes the organic layer 3. Is preferably at least 5 dyne / cm or more.

FIG. 2 shows an example of the configuration of the partition 5 composed of the first partition 51 and the second partition 52. Here, the partition 5 is formed by superimposing the second partition 52 (upper partition) distal to the first electrode 2 on the first partition 51 (lower partition), and the inner wall surface of the second partition 52 at 20 ° C. The surface tension γc ₍₅₂₎ is configured to be smaller than the surface tension γ at 20 ° C. of the organic layer forming coating liquid. The material of the first partition 51 is the same as the material of the partition 5 described above. As the material of the second partition 52, the above-described material forming the first partition 51 can be used.
Surface tension γc ₍₅₂₎ and coating liquid for forming organic layer
A material having a critical surface tension γc value smaller than the critical surface tension γc ₍₅₁₎ at 20 ° C. of the inner wall surface of the first partition wall 51 so that the surface tension γ at 0 ° C. satisfies the relationship of γc ₍₅₂₎ <γ. The use of is preferred. Alternatively, after forming the second partition wall 52 using these materials, the value of the critical surface tension γc of the surface of the second partition wall 52 may be controlled by performing plasma processing, UV processing, gas processing, or the like. .
If the difference between the critical surface tension γc of the second partition 52 at 20 ° C. and the surface tension γ of the organic layer forming coating liquid at 20 ° C. is at least 5 dyne / cm or more, the second partition 52 formed by the organic layer forming coating liquid is used. Weakness of the inner wall surface can be effectively prevented.

The first partition 51 and the second partition 52 need only be formed at least at a part between pixels, and the structure of the partitions 51 and 52 may be a multilayer structure in which the respective partitions are overlapped. Preferably, it is insoluble or hardly soluble in the solvent of the coating liquid for forming an organic layer. Further, in order to improve the display quality as a display, it is preferable to use a material for a black matrix. First partition 51
The cross-sectional shape of the second partition 52 is not particularly limited,
The cathode may be patterned by forming it into an inversely tapered cross-sectional shape as disclosed in JP-A-11-87063.

The organic layer 3 has a structure having at least one organic layer, and may have a single-layer structure composed of only organic layers or a multilayer structure composed of a charge transport layer and an organic layer. In the case of a multilayer structure of the charge transport layer and the organic layer,
The charge transport layer and the organic layer may each be a single layer, or a plurality of the above layers may be used. Also, the organic layer 3
In the case of a multilayer structure including a plurality of organic layers, at least one of the organic layers needs to be formed by a wet method. At this time, the other organic layer may be formed by a wet method, or may be formed by a dry process such as a vacuum evaporation method.

The material of the organic layer 3 is not particularly limited as long as at least one layer is formed by a wet method capable of forming a thin film from the state of a coating liquid (coating liquid for forming an organic layer). Examples of the wet method include a spin coating method, a printing method, a dip method,
Doctor blade method, electrodeposition method, inkjet head,
Although there are various thin film forming methods such as a method of discharging a liquid from a nozzle or a needle, as described later, a suitable material (a coating liquid for forming an organic layer) is slightly different depending on a method to be used. However, the surface tension γ of the coating liquid for forming an organic layer at 20 ° C. is lower than the critical surface tension γ of the first partition wall 51 at 20 ° C.
c, and the critical surface tension γc of the electrode 2 at 20 ° C. must be smaller.

The coating liquid for forming an organic layer used in the wet method is as follows:
It can be divided into a coating solution for forming a light emitting layer and a coating solution for forming a charge transport layer. Examples of the coating liquid for forming a light emitting layer include known polymer light emitting materials for organic LEDs, for example, poly [2-decyloxy-1,4-phenylene] (DO-PPP), poly [2,5-bis [2- (N, N, N-triethylammonium) ethoxy] -1,4-phenylene-alto-
1,4-phenylene] dibromide (PPP-NE
t ₃ ⁺ ), poly [2- (2′-ethylhexyloxy)-
5-methoxy-1,4-phenylenevinylene] (MEH
-PPV), poly [5-methoxy- (2-propanoxysulfonide) -1,4-phenylenevinylene] (MP
S-PPV), poly [2,5-bis (hexyloxy)
-1,4-phenylene- (1-cyanovinylene)] (C
N-PPV) or the like, or a coating liquid in which the compound is dissolved or dispersed, or a known low-molecular light-emitting material for an organic LED such as tetraphenylbutadiene (TPB), coumarin, nile red, or an oxadiazole derivative. Polymer materials such as polycarbonate (PC), polymethyl methacrylate (PMMA), polyvinyl carbazole (PV
A coating solution in which Cz) or the like is dissolved or dispersed can be used. In addition, these coating liquids may contain additives for pH adjustment, viscosity adjustment, filling promotion, leveling, surface tension adjustment, etc., as necessary, and well-known holes for organic LEDs and organic photoconductors. Transport materials (eg, N, N'-bis- (3-methylphenyl) -N, N'-bis- (phenyl) -benzidine (TPD), N, N'-di (naphthalen-1-yl)- N, N'-diphenyl-benzidine (NPD) and the like, electron transporting materials (for example, 3- (4-biphenylyl-4--4-phenylene-5-t-butylphenyl-1,2,4-triazole (TAZ) ), Tris (8-hydroxyquinolinonato) aluminum (Alq
₃ ) A charge transporting material such as ₃ ) and a dopant such as an acceptor and a donor may be added.

As the coating liquid for forming the charge transport layer, organic LE
Known polymer charge transport materials for D and organic photoconductors (for example, polyaniline (PANI), 3,4-polyethylenedioxythiophene (PEDT), poly [triphenylamine derivative] (Poly-TPD), [Oxadiazole derivative] (Poly-OXZ etc.), PV
Coating solution in which Cz is dissolved or dispersed, or organic L
Known low molecular charge transport materials for EDs and organic photoconductors (eg, TPD, NPD, oxadiazole derivatives, etc.) and known polymer materials (eg, PC, P
MMA, PVCz, etc.) can be used. If necessary, additives such as pH adjustment, viscosity adjustment, filling promotion, leveling, surface tension adjustment, and dopants such as acceptors and donors may be added to these liquids.

When the ink-jet method is used, conventional solvents can be used as a solvent for dissolving or dispersing the above-mentioned polymer material. Among these solvents, low-vapor-pressure solvents such as, for example, Ethylene glycol, propylene glycol, triethylene glycol,
Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, glycerin, formamide, N-methyl-2
-Pyrrolidone, cyclohexane, 1-propanol, octane, nonane, decane and the like are preferably contained.
The mixing ratio between the solid content and the solvent is preferably adjusted so that the viscosity of the coating solution at 20 ° C. becomes 10 mPa · s or less, and the surface tension γ is adjusted so as to be at least 30 dyne / cm or more. preferable.

Further, another organic layer in the organic layer 3 can be formed between the electrodes 2 and 4 by a conventional dry process, for example, a resistance heating evaporation method, an EB evaporation method, an ion plating method, or the like. As the organic light-emitting material that can be used in the dry process, a known light-emitting material for an organic LED can be used. The light-emitting material may be composed of only the organic light-emitting material, or may contain an additive or the like. As the charge transport material, known materials for organic LEDs and organic photoconductors can be used. The charge transport material may be composed of only the charge transport material, or may contain an additive or the like.

Next, the arrangement of the organic layer 3 for forming an organic LED display by arranging a plurality of organic light emitting elements 10 will be described with reference to the plan view of FIG. The organic layer 3 includes three types of red (R) light-emitting pixels 11, green (G) light-emitting pixels 12, and blue (B) light-emitting pixels 13. The organic LED display 20 of the present invention includes these three types of organic layers. 3 are arranged in a predetermined arrangement pattern in a matrix.

FIG. 3A shows a structure in which the light-emitting pixels of the respective colors described above are arranged in a stripe pattern. In FIG. 3B, the light-emitting pixels of the above-described respective colors are arranged in a diagonal stripe shape adjacent to the corner of the partition wall 5. In FIG. 3C, the organic layer 3 (partition wall 5) meanders, and the light emitting pixels of each color described above are arranged in a staggered manner. In the arrangement of these light-emitting pixels, as shown in FIG. 3D, the number of red (R) light-emitting pixels 11, green (G) light-emitting pixels 12, and blue (B) light-emitting pixels 13 is not necessarily 1: The ratio does not have to be 1: 1. Further, the area of each pixel may be the same, or may be different for each pixel. Also, instead of three types (three colors), one
The type (one color) may be used.

Next, a method of connecting the first electrode 2 and the second electrode 4 corresponding to each pixel will be described with reference to the plan views of FIGS. As shown in FIG. 4, the organic LED display 20 of the present invention may have an oblique stripe electrode configuration in which the first electrode 2 and the second electrode 4 sandwiching the organic layer 3 are orthogonal to each other on the common substrate 1. Good. Further, as shown in FIG. 5, the first electrode 2 or the second electrode 4
May be connected to a common electrode via a thin film transistor 21 (TFT) connected by a predetermined source bus line 22 and a predetermined gate bus line 23. However, the number of TFTs used for one pixel may be one or more than one.

[0034]

EXAMPLES Specific examples of the embodiments will be shown below, but the present invention is not limited by these examples. Example 1 First, a glass substrate 1 with ITO having a film thickness of 130 nm
To 24 as the first electrode 2 by photolithography.
ITO transparent stripe electrodes having a width of 200 μm were formed at a pitch of 0 μm. Next, the glass substrate 1 with ITO is cleaned by a conventional wet process using, for example, isopropyl alcohol, acetone, and pure water, and a conventional dry process such as UV ozone treatment and plasma treatment. At this time, the critical surface tension γc of the ITO surface is 5
It was 6 dyne / cm.

Next, a polyimide resist having a critical surface tension γc of 38 dyne / cm was applied on the substrate 1 by spin coating to form a resist film having a thickness of 30 μm. Next, exposure is performed using a mask, the resist residue is washed away, and a pitch of 540 μm is set in a direction parallel to the ITO.
At a pitch of 230 μm in the direction orthogonal to ITO, 40 μm
A first partition 51 having a width of m was formed.

Next, the substrate 1 is subjected to a dry hydrophilization treatment using an F ₂ -containing gas to make the critical surface tension γc of the ITO surface 61 dyne / cm and the critical surface tension γc of the first partition wall 51 to 60 dyne / cm. cm. Then, using a commercially available dispenser, an aqueous solution of 3,4-polyethylenedioxythiophene having a surface tension γ of 33 dyne / cm 2 and a thickness of 50 nm were used.
Was formed.

Next, using a commercially available dispenser, red,
A luminescent material that emits green and blue light was patterned and applied to form an organic layer 3 having a thickness of 50 nm. Here, as a red light emitting material, a cyanopolyphenylene vinylene precursor, as a green light emitting material, a polyphenylene vinylene precursor,
Polyparaphenylene was used as a blue light emitting material.
At this time, the surface tension γ of all the organic layer forming coating liquids is
It was 38 dyne / cm. However, the cyanopolyphenylenevinylene precursor and the polyphenylenevinylene precursor were converted into cyanopolyphenylenevinylene and polyphenylenevinylene by performing a heat treatment at 150 ° C. for 6 hours in an Ar atmosphere after forming the film.

Next, as the second electrode 4, a thickness of 0.2 μm
Al, Li are co-evaporated using a shadow mask having a width of 510 μm, a width of 510 μm, and a pitch of 540 μm.
An i-alloy electrode was formed. Finally, sealing was performed using an epoxy resin. In the organic LED display formed as described above, between the first electrode 2 and the second electrode 4, no short circuit occurs between the first electrode 2 and the second electrode 4. Non-uniform light emission from the edge of the pixel portion due to non-uniform thickness of the charge transport layer was not observed.
Further, by applying a pulse voltage of 30 V to this display, light emission was obtained from all the pixels.

Example 2 First, a glass substrate 1 with ITO having a thickness of 130 nm was used.
To 24 as the first electrode 2 by photolithography.
ITO transparent stripe electrodes having a width of 200 μm were formed at a pitch of 0 μm. Next, the glass substrate 1 with ITO is cleaned by a conventional wet process using isopropyl alcohol, acetone, and pure water, and a conventional dry process such as UV ozone treatment and plasma treatment. At this time, the critical surface tension γc of the ITO surface is 5
It was 6 dyne / cm.

Next, a 0.1 μm-thick resist film was formed on the substrate 1 by spin coating using polyethylene terephthalate having a critical surface tension γc of 43 dyne / cm. Next, the resist is exposed using a mask, and the resist residue is washed away, and a pitch of 340 μm is set in a direction parallel to the ITO.
At a pitch of 230 μm in the direction orthogonal to ITO, 40 μm
A first partition 51 having a width of m was formed. Next, a 20 μm-thick resist film was formed on the first electrode 2 by spin coating using perfluorooctylethyl methacrylate having a critical surface tension γc of 15 dyne / cm 2. Next, the first electrode 2
Exposure is performed using a mask having a pattern similar to that described above, and the residue of the resist is washed away.
A second partition 52 having a width of 40 μm was formed.

Next, a hole injection layer having a thickness of 50 nm was formed using a 3,4-polyethylenedioxythiophene aqueous solution having a surface tension γ of 33 dyne / cm by a commercially available spin coater. Next, with a commercially available dispenser, red,
A light-emitting material that emits green and blue light was applied by patterning to form a light-emitting layer having a thickness of 50 nm. Here, a cyanopolyphenylenevinylene precursor was used as the red light-emitting material, a polyphenylenevinylene precursor was used as the green light-emitting material, and polyparaphenylene was used as the blue light-emitting material. At this time, the surface tension γ of all the coating liquids for forming an organic layer is 38 dy.
ne / cm. However, regarding the cyanopolyphenylene vinylene precursor and the polyphenylene vinylene precursor,
After forming the film, each was converted into cyanopolyphenylenevinylene and polyphenylenevinylene by performing a heat treatment at 150 ° C. for 6 hours in an Ar atmosphere.

Next, as the second electrode 4, a thickness of 0.2 μm
Al, Li are co-evaporated using a shadow mask having a width of 510 μm, a width of 510 μm, and a pitch of 540 μm.
An i-alloy electrode was formed. Finally, sealing was performed using an epoxy resin. In the organic LED display formed as described above, between the first electrode 2 and the second electrode 4, no short circuit occurs between the first electrode 2 and the second electrode 4. Non-uniform light emission from the edge of the pixel portion due to non-uniform thickness of the charge transport layer was not observed.
Further, by applying a pulse voltage of 30 V to this display, light emission was obtained from all the pixels.

Example 3 An organic LED display was formed in the same manner as in Example 2, except that a commercially available ink jet printer was used in place of the dispenser as a method of discharging the coating liquid for forming an organic layer. As shown in FIG. 6, the discharge of the coating liquid for forming an organic layer by the inkjet printer is performed by arranging three inkjet heads 24 corresponding to the intervals of the partition walls 5 formed in a matrix in a predetermined arrangement pattern. The red (R) light-emitting pixels 11, the green (G) light-emitting pixels 12, and the blue (B) light-emitting pixels 13 are ejected from the inkjet head 24 onto the first electrode 2 inside the partition wall 5, and these inkjet heads 24 are arranged in parallel. The organic layer 3 was formed by moving and repeating the above-described discharge of the luminescent pixels. The formed organic LED display has a first electrode 2
Between the first electrode 2 and the second electrode 4
No short circuit occurred between the pixels, and nonuniform light emission from the edge of the pixel portion due to nonuniform film thickness of the organic layer 3 and the charge transport layer was not observed. Further, by applying a pulse voltage of 30 V to this display, light emission was obtained from all the pixels.

Example 4 First, after forming a thin film transistor on a glass substrate 1, a first electrode 2 having a long side of 500 μm and a short side of 2
An ITO transparent electrode was formed to have a thickness of 20 μm. At this time, the critical surface tension γc of the ITO surface was 56 dyne / cm 2. Next, the critical surface tension γc is 43 dy on this substrate.
A 0.1 μm-thick resist film was formed by spin coating using polyethylene terephthalate of ne / cm 2.
Next, exposure was performed using a mask, and the residue of the resist was washed away, thereby forming a first partition wall 51 having a width of 40 μm between ITO.

Next, a 20 μm-thick resist film was formed on the first electrode 2 by spin coating using perfluorooctylethyl methacrylate having a critical surface tension γc of 15 dyne / cm. Next, exposure is performed using a mask having the same pattern as that of the first electrode 2, and the residue of the resist is washed away.
A second partition 52 having a width of 40 μm was formed between the ITOs. Next, an organic layer 3 was formed in the same manner as in Example 2. next,
By co-evaporating Al and Li as the second electrode 4,
An AlLi alloy electrode was formed. Finally, sealing was performed using an epoxy resin.

In the organic LED display formed as described above, no short circuit occurs between the first electrode 2 and the second electrode 4 and between the first electrode 2 and the second electrode 4. Non-uniform light emission in each pixel due to non-uniform thickness of the layer 3 and the charge transport layer was not observed. Further, by applying a pulse voltage of 30 V to this display, light emission was obtained from all the pixels.

[0047]

According to the present invention, an organic light-emitting device in which local light emission at the interface between the organic layer and the partition wall and deterioration with time due to the local light emission are suppressed, and an electrode is formed on the surface of the organic layer using a shadow mask or the like. In this case, it is possible to provide a method for manufacturing an organic light-emitting device that facilitates alignment of a shadow mask. Further, an organic light emitting display having excellent display quality and a high aperture ratio can be provided.

Further, it is possible to suppress color mixture due to mixing of the light emitting layers or light emission of a low energy color due to energy transfer occurring between the light emitting materials due to mixing of the light emitting layers, thereby preventing a remarkable decrease in display quality. Further, when the second electrode is formed using the shadow mask, damage to the organic layer due to close contact of the shadow mask can be prevented. In this case, the shape of the partition is an appropriate shape, for example,
With the reverse tapered shape, the second electrode can be patterned without using a shadow mask.

Further, since contamination of the material of the adjacent pixels by the material can be prevented, problems such as color mixing can be eliminated.
Further, by using an electrode whose critical surface tension γc at 20 ° C. is larger than the surface tension γ of the coating liquid for forming an organic layer at 20 ° C., the wetting property of the coating liquid for forming an organic layer on the electrode is enhanced, and The coating liquid for forming an organic layer can be filled up to the corners and corners, and a uniform organic layer can be formed over the entire area of the pixel. Further, the adhesion between the organic layer and the electrode is improved, and the efficiency of charge injection from the electrode to the organic layer is improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a configuration example of an organic light emitting device according to the present invention.

FIG. 2 is a schematic sectional view showing another configuration example of the organic light emitting device according to the present invention.

FIG. 3 is a schematic partial plan view showing an arrangement example of a light emitting layer of the organic LED display according to the present invention.

FIG. 4 is a schematic partial perspective plan view illustrating a configuration example of an electrode of an organic LED display according to the present invention.

FIG. 5 is a schematic partial perspective plan view corresponding to FIG. 4 and illustrating another configuration example of the electrodes of the organic LED display.

FIG. 6 is a conceptual diagram illustrating an example of a method for forming an organic layer according to the present invention.

FIG. 7 is a schematic sectional view showing a configuration example of a conventional organic light emitting device.

FIG. 8 is a schematic sectional view showing another configuration example of the conventional organic light emitting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 1st electrode 3 Organic layer 4 2nd electrode 5 Partition 6 Sealing film 7 Deflection plate 10 Organic light emitting element 11 Red light emitting pixel 12 Green light emitting pixel 13 Blue light emitting pixel 20 Organic LED display 21 Thin film transistor (TFT) 22 Source bus Line 23 Gate bus line 24 Inkjet head 51 First partition 52 Second partition

Claims (9)

[Claims] 1. A first electrode, a partition formed on the first electrode and partitioning at least a part between adjacent pixels, an organic layer formed inside the partition, and formed on the organic layer An organic light-emitting device comprising a second electrode and at least one organic layer, wherein a surface near a partition wall has a concave cross-sectional shape. 2. The organic layer according to claim 1, wherein the concave meniscus is solidified when a solution or dispersion containing an organic light emitting material and / or an organic charge transport material is injected into the inside of the partition. Organic light emitting device. 3. A partition partitioning at least a part between adjacent pixels is formed on the first electrode, and a solution or a dispersion containing an organic light emitting material is injected into the partition to form an organic layer. In the method for manufacturing an organic light-emitting device having a step of forming a second electrode on the organic layer, the critical surface tension of the partition at 20 ° C. is set to 20 ° C. of the solution or dispersion containing the organic light-emitting material to be injected inside the partition. A method of manufacturing an organic light-emitting device, wherein the method is larger than the surface tension of the light-emitting device. 4. The production of an organic light emitting device according to claim 3, wherein the difference between the critical surface tension of the partition at 20 ° C. and the surface tension of the solution or dispersion containing the organic light emitting material at 20 ° C. is at least 5 dyne / cm or more. Method. 5. A partition wall further comprising an upper partition wall that is distal to the first electrode, wherein a critical surface tension at 20 ° C. of the upper partition wall is equal to that of a solution or dispersion containing an organic light emitting material.
The method according to claim 3, wherein the surface tension is lower than a surface tension at 0 ° C. 6. 6. The organic light-emitting device according to claim 5, wherein the difference between the critical surface tension of the upper partition at 20 ° C. and the surface tension of the solution or dispersion containing the organic light-emitting material at 20 ° C. is at least 5 dyne / cm or more. Production method. 7. The organic light emitting device according to claim 3, wherein a critical surface tension at 20 ° C. of the first electrode is larger than a surface tension at 20 ° C. of a solution or a dispersion containing the organic light emitting material. Device manufacturing method. 8. The organic light emitting device according to claim 7, wherein the difference between the critical surface tension of the first electrode at 20 ° C. and the surface tension of the solution or dispersion containing the organic light emitting material at 20 ° C. is at least 5 dyne / cm or more. Manufacturing method. 9. At least one organic layer is formed from a solution or a dispersion containing an organic light emitting material by using an injection method selected from a spin coating method, a printing method, an ink jet method, and a nozzle injection method. Claim 3-
9. The method for manufacturing an organic light-emitting device according to any one of 8.