JPH10308286A - Organic electroluminescent light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device, which has excellent light emitting efficiency and in which generation of effuse of light and light emission failure is lowered and which has excellent visibility, by laminating a lower electrode pattern, an organic material layer including a light emitting layer, and an upper electrode pattern in order on a transparent substrate, and providing a light reflecting layer for reflecting the visible light, which has a specified wave length, in at least one side surface of the lower electrode pattern. SOLUTION: A lower electrode (pattern) 2, an organic material layer 3 including a light emitting layer, and an upper electrode (pattern) 4 are laminated in order on a transparent substrate 1 such as a glass board so as to form an organic electroluminescent light emitting device. A light reflecting layer 5 for reflecting the visible light, which has a wave length at 400-700 nm, is arranged in at least one side surface of the lower electrode 2. Namely, the reflecting layer 5 always exists in a side surface of the lower electrode 2, and all clearances between the lower electrodes 2 are filled with the reflecting layer 5 at need. The light from the organic material layer 3, which includes the light emitting layer, is reflected by the side surface of the lower electrode 2, and provides it to the sight of human being.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an organic EL light emitting device. More specifically, consumer and industrial display devices,
The present invention relates to an organic EL light emitting device suitably used for a color display or the like.

[0002]

2. Description of the Related Art EL devices have the characteristics of high visibility due to self-emission, and excellent impact resistance due to being completely solid. Further, since they are thin-film surface-emitting devices, they are thin and lightweight. Development as a light emitting device is underway. EL elements use an inorganic or organic compound as a light-emitting layer. In particular, an organic EL element in which an organic compound is sandwiched between two electrodes has a wide variety of organic compounds and can efficiently emit light of various colors and high luminance. Since it emits light at the same time, expectations for a next-generation light emitting device are high.

In an organic EL light emitting device, an organic compound containing a light emitting layer is sandwiched between two electrodes, that is, an upper electrode and a lower electrode, and voltages having different polarities are applied to the respective electrodes to thereby center the light emitting layer. Emits light, for example,
When the stripe-shaped upper electrode pattern and the lower electrode pattern are made orthogonal to each other, the intersection thereof emits light, and (X
-Y dot matrix type (FIG. 6), it is generally well known that any display can be performed by arbitrarily applying a voltage to each stripe electrode.

At this time, by making either the upper electrode or the lower electrode transparent, light emitted from the organic EL element can be extracted to the outside. In particular, if the lower electrode on the light-transmitting substrate is transparent, EL light emission can be extracted from the light-transmitting substrate side. However, if the lower electrode is transparent as shown in FIG. Light from the layer leaked from the side surface of the lower electrode and was lost, and the light could not be efficiently delivered to human vision outside the device. In addition, blurring of light occurs, and a display with good contrast cannot be obtained, and it cannot be said that the organic EL light emitting device has good visibility.
No. 233891, JP-A-5-275172, etc.).

In an inorganic EL (thin film EL) having a light emitting layer made of inorganic material, a black insulating layer (oxygen-deficient Ta ₂ O) having the same thickness as the lower electrode is provided between the lower electrodes (transparent electrodes).
₅ ) is disclosed (JP-A-3-4484).
No.). The presence of the black insulating layer prevents light bleeding and provides a display with good contrast. However, it only absorbs the light emitted from the EL element, so that light could not be efficiently extracted to the outside (FIG. 8). .

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has an excellent luminous efficiency, has less occurrence of light bleeding and luminous defects, and has excellent visibility. It is intended to provide a device.

[0007]

According to the present invention, there is provided the following organic EL light emitting device. [1] In an organic EL light emitting device in which a lower electrode pattern, an organic layer including a light emitting layer, and an upper electrode pattern are sequentially laminated on a light-transmitting substrate, a wavelength of 400 to 700 nm is provided on at least side surfaces of the lower electrode pattern. An organic EL light-emitting device, comprising a light-reflecting layer in the visible region described above. [2] The organic EL light-emitting device according to [1], wherein the cross-sectional shape of the lower electrode pattern is gradually or stepwise enlarged toward the light-transmitting substrate. [3] The organic EL light emitting device according to [1] or [2], wherein a gap between the lower electrode patterns is filled with a flattening layer so as to flatten irregularities due to the lower electrode pattern. [4] A wavelength 40 of the reflection layer and / or the planarization layer.
The light transmittance in the visible region of 0 to 700 nm is 10
% Or less, the organic EL light-emitting device according to any one of [1] to [3]. [5] The organic EL light-emitting device according to any one of [1] to [4], wherein the lower electrode pattern has a thickness of 0.2 μm or more.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the organic EL light-emitting device of the present invention will be specifically described with reference to the drawings. 1. First Embodiment FIG. 1 is a sectional view schematically showing a first embodiment of the organic EL light emitting device of the present invention. As shown in FIG. 1, the organic EL light emitting device of the present invention is configured by sequentially laminating a lower electrode pattern 2, an organic material layer 3 including a light emitting layer, and an upper electrode pattern 4 on a light transmitting substrate 1. On at least a side surface of the lower electrode pattern 2, a reflection layer 5 for light in a visible region having a wavelength of 400 to 700 nm is provided. Here, at least the side surface of the lower electrode pattern 2 means that the reflective layer always exists on the side surface of the lower electrode pattern, and may fill all the gaps between the lower electrode patterns as needed. With this configuration, light from the organic material layer 3 including the light-emitting layer is reflected on the side surface of the lower electrode pattern 2, and the light can be efficiently delivered to the outside human vision. That is, luminous efficiency can be increased. In addition, blurring of light is prevented, a display with good contrast is obtained, and an organic EL light emitting device with good visibility is obtained.

[0009] 2. Second Embodiment FIG. 2 is a sectional view schematically showing a second embodiment of the organic EL light emitting device of the present invention. As shown in FIG. 2, in this embodiment, the cross-sectional shape of the lower electrode pattern 2 is gradually (FIG. 2A) or stepwise (FIG. 2B) toward the translucent substrate 1. It has been expanded. Therefore, the reflection layer 5 disposed on the side surface of the lower electrode pattern 2 is inclined toward the light transmitting substrate 1. With this configuration, light emission from the point P of the organic material layer 3 is expanded in the range of L _{1 to} L ₂ around the direct light transmission direction L.
Therefore, the light can be more efficiently extracted to the outside, and the distortion of the thin organic material layer 3 and the upper electrode pattern 4 laminated on the lower electrode pattern 2 can be reduced.
Disconnection, short-circuit between the lower electrode pattern 2 and the upper electrode pattern 4, and light-emitting defects such as crosstalk (light emission other than the desired light-emitting portion due to short-circuit between the electrodes) can be prevented.

[0010] 3. Third Embodiment FIG. 3 is a sectional view showing a third embodiment of the organic EL light emitting device of the present invention. As shown in FIG. 3, in this embodiment, the gap between the lower electrode patterns 2 is filled with a flattening layer 6 so as to flatten the unevenness due to the lower electrode pattern 2. With this configuration, as described above, the thin organic material layer 3 laminated on the lower electrode 2
In addition, the distortion of the upper electrode pattern 4 can be reduced, and light emission defects can be prevented.

4. Fourth Embodiment FIG. 4 is a cross-sectional view showing a fourth embodiment of the organic EL light emitting device of the present invention. As shown in FIG. 4, in this embodiment, the wavelength 4 of the reflection layer 5 and / or the planarization layer 6 is used.
The light transmittance in the visible region of 00 to 700 nm is 10
% Or less. Here, the transmittance of light means a ratio (percentage) of the energy of light passing through the layer to the energy of light entering the reflective layer and / or the planarizing layer. With such a configuration, the organic material layer 3 between the adjacent lower electrode patterns 2 is formed.
And almost external light from the gap between the upper electrode patterns 4 is shielded, whereby a display with better contrast without light bleeding can be obtained.

5. Fifth Embodiment Furthermore, a fifth embodiment of the present invention is proposed. In this embodiment, the lower electrode pattern 2 has a thickness of 0.2 μm.
m or more. With this configuration, the electric resistance of the lower electrode pattern 2 is reduced.
Although unevenness in light emission due to a voltage drop in the organic EL light emitting display is reduced, the effect of the reflective layer 5 on the side surface of the pattern is increased because the lower electrode pattern 2 is made thicker.

By applying the organic EL light emitting device of the present invention, the light emitting layer of each organic material layer may be formed as a different layer to emit multicolor light, or a different light emitting layer may be provided between the light transmitting substrate and the lower electrode pattern. Multicolor light emission may be performed by disposing a phosphor layer and a color filter layer.

6. Components Hereinafter, components used in the organic EL light emitting device of the present invention will be specifically described. (1) Translucent substrate The translucent substrate is a smooth and electrically insulating substrate that can support the organic EL light emitting device, and has a translucency, that is, a wavelength of 400 to 400 nm.
It is preferable that the transmittance of light in a visible region of 700 nm is 50% or more. Specifically, a glass plate, more specifically,
Soda-lime glass, barium, strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, quartz glass, and the like can be given. Examples of the polymer plate include polycarbonate, acrylic, polyether sulfide, polysulfone, and polyimide.

(2) Organic EL Element In the present invention, the configuration is described as an organic EL light emitting device, but this means an individual pixel aggregate of a display unit, that is, an aggregate of organic EL devices. Here, an organic EL element as a basic unit will be described. In the present invention, the lower electrode is a transparent electrode, and if one of the anode and the cathode described below is transparent, it can be selected as the lower electrode and the other is selected as the upper electrode. be able to.

In the organic EL device used in the present invention, an organic layer having at least a recombination region and a light emitting region is used. Since the recombination region and the light-emitting region are usually present in the light-emitting layer, in the present invention, only the light-emitting layer may be used as the organic material layer. An electron injection layer, an organic semiconductor layer, an electron barrier layer, an adhesion improving layer, and the like can also be used.

Next, a typical configuration example of the organic EL device used in the present invention will be described. Of course, it is not limited to this. Anode / light-emitting layer / cathode anode / hole-injection layer / light-emitting layer / cathode anode / light-emitting layer / electron injection layer / cathode anode / hole-injection layer / light-emitting layer / electron injection layer / cathode anode / organic semiconductor layer / light-emitting layer / Cathode anode / organic semiconductor layer / electron barrier layer / emission layer / cathode anode / hole injection layer / emission layer / adhesion improving layer / cathode. Among these, a normal configuration is preferably used.

(2) -1. Anode For the anode, a metal with a large work function (4 eV or more)
Those using an alloy, an electrically conductive compound or a mixture thereof as an electrode material are preferably used. Specific examples of such an electrode material include metals such as Au, CuI, ITO,
Conductive materials such as SnO ₂ and ZnO can be used. The anode is formed by depositing these electrode materials by vapor deposition, sputtering,
It can be manufactured by forming a thin film by a method such as a VP method, an ion plating method, an electrodeposition method, an electroplating method, and a chemical plating method. When light emitted from the light emitting layer is extracted from the anode in this manner, it is preferable that the transmittance of the anode with respect to the light emission be greater than 10%. The sheet resistance of the anode is preferably several hundred Ω / □ or less. Although the thickness of the anode depends on the material, it is usually 10 nm to 100 μm in the present invention.
m, preferably 100 nm to 10 μm, more preferably 200 nm (0.2 μm) to 5 μm. In this case, it is easier to reduce the upper limit in processing as the definition of the anode pattern increases, but the upper limit is particularly limited in view of lower power consumption of the organic EL light emitting device (lower resistance of the electrode). More preferably, the thickness is 0.2 μm or more.

(2) -2. Light-Emitting Layer The light-emitting material of the organic EL device is mainly an organic compound, and specific examples include the following compounds depending on a desired color tone. First, in the case of emitting purple light from the ultraviolet region, a compound represented by the following general formula may be mentioned.

[0020]

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In this general formula, X represents the following compound.

[0022]

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Here, n is 2, 3, 4 or 5.
Y represents the following compound.

[0024]

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The phenyl group, phenylene group,
The naphthyl group includes an alkyl group having 1 to 4 carbon atoms, an alkoxy group, a hydroxyl group, a sulfonyl group, a carbonyl group, an amino group,
A dimethylamino group, a diphenylamino group or the like may be used alone or plurally. These may be combined with each other to form a saturated 5-membered ring or 6-membered ring. Further, those bonded to a phenyl group, a phenylene group, or a naphthyl group at the para position are preferable for forming a smooth evaporated film having good bonding properties. Specifically, they are the following compounds. Especially,
P-quarterphenyl derivatives and p-quinphenyl derivatives are preferred.

[0026]

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[0027]

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[0028]

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[0029]

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Next, in order to obtain blue to green light emission, for example, a benzothiazole-based, benzimidazole-based, benzoxazole-based fluorescent whitening agent, a metal chelated oxinoid compound, and a styrylbenzene-based compound are mentioned. Can be.

Specific examples of the compound names include those disclosed in JP-A-59-194393. Typical examples thereof include benzoxazole-based, benzothiazole-based, and benzimidazole-based fluorescent whitening agents. In addition, other useful compounds include chemistry of synthetic
Soybean 1971, pages 628-637 and 640.

As the chelated oxinoid compound, for example, those disclosed in JP-A-63-295695 can be used. A typical example is tris (8-quinolinol) aluminum (hereinafter referred to as A
8-hydroxyquinoline-based metal complex such as 1q) and dilithium epthridione.

Further, as the styrylbenzene-based compound, for example, those disclosed in European Patent No. 0319881 or European Patent No. 03753582 can be used.

Further, a distyrylpyrazine derivative disclosed in JP-A-2-252793 can also be used as a material for the light emitting layer. As other materials, for example, a polyphenyl-based compound disclosed in European Patent No. 0377715 can also be used as a material for the light-emitting layer.

Further, in addition to the above-described fluorescent whitening agent, metal chelated oxinoid compound, styrylbenzene compound and the like, for example, 12-phthaloperinone (J. Appl.
Phys., Vol. 27, L713 (1988)), 1, 4
-Diphenyl-1,3-butadiene, 1,1,4,4-
Tetraphenyl-1,3 butadiene (Appl. Phys.
Lett., Vol. 56, L799 (1990)), naphthalimide derivative (JP-A-2-305886), perylene derivative (JP-A-2-189890), oxadiazole derivative (JP-A-2-216791). Gazettes, or oxadiazole derivatives disclosed by Hamada et al. At the 38th Lecture Meeting on Applied Physics, aldazine derivatives (JP-A-2-220393), pyrazirine derivatives (JP-A-2-220394), Cyclopentadiene derivatives (JP-A-2-289675), pyrrolopyrrole derivatives (JP-A-2-29691),
Styrylamine derivatives (Appl. Phys. Lett., Vol. 56,
L799 (1990)), coumarin compounds (JP-A-2-191694), and WO90 / 1.
3148 and Appl. Phys. Lett., Vol 58, 18, P1982 (1991)
Can be used as a material for the light emitting layer.

In the present invention, an aromatic dimethylidin compound (European Patent No. 038876) is particularly used as a material for the light emitting layer.
No. 8 and JP-A-3-231970) are preferably used. As a specific example,
4'-bis (2,2-di-t-butylphenylvinyl)
Biphenyl, (hereinafter abbreviated as DTBPBBi),
4,4′-bis (2,2-diphenylvinyl) biphenyl (hereinafter abbreviated as DPVBi) and the like and derivatives thereof can be given.

Further, a compound represented by the general formula (R _S -Q) ₂ -AL-OL described in JP-A-5-258882 and the like
And a compound represented by the formula: (Where L is a hydrocarbon of 6 to 24 carbon atoms comprising a phenyl moiety, OL is a phenolate ligand, Q is a substituted 8-quinolinolate ligand, R _S Represents an 8-quinolinolate ring substituent selected to sterically hinder the binding of more than two substituted 8-quinolinolate ligands to the aluminum atom. Specifically, bis (2-
Methyl-8-quinolinolate) (para-phenylphenolate) aluminum (III) (hereinafter PC-7), bis (2-methyl-8-quinolinolate) (1-naphtholate) aluminum (III) (hereinafter PC-17), etc. Is mentioned. In addition, there is a method of obtaining highly efficient mixed emission of blue and green light using doping according to JP-A-6-9953. In this case, as the host, the luminescent material described above, and as the dopant, a strong fluorescent dye from blue to green, for example, a coumarin-based fluorescent dye or a fluorescent dye similar to that used as the host described above may be used. it can. Specifically, a luminescent material having a distyrylarylene skeleton as the host, particularly preferably, for example, DPVBi, and a dopant as diphenylaminovinylarylene, particularly preferably, for example, N, N-diphenylaminovinylbenzene (DPAVB).

The light emitting layer for obtaining white light emission is not particularly limited, but the following can be mentioned. A white light emitting element is described as an example of an element using tunnel injection as in the element using the tunnel injection, which specifies the energy level of each layer of the organic EL laminated structure and emits light using tunnel injection (European Patent Publication No. 0390551). (Japanese Unexamined Patent Application Publication No. 3-23)
No. 0584) A light emitting layer having a two-layer structure is described (Japanese Unexamined Patent Publication No.
Japanese Patent Application Laid-Open No. 220390 and Japanese Patent Application Laid-Open No. 216790/1990 The light-emitting layer is divided into a plurality of layers and each is made of a material having a different emission wavelength (Japanese Patent Application Laid-Open No. 4-51491). And a green light emitter (480 nm to 580 nm),
Further, a structure containing a red phosphor (Japanese Unexamined Patent Publication No.
207170) A structure in which a blue light-emitting layer contains a blue fluorescent dye, a green light-emitting layer has a region containing a red fluorescent dye, and further contains a green phosphor (Japanese Patent Application Laid-Open No. 7-142169) Are preferably used. Here, an example of a red phosphor that emits red light is shown in [Formula 8].

[0039]

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As a method of forming a light emitting layer using the above-mentioned materials, a known method such as a vapor deposition method, a spin coating method, and an LB method can be applied. The light emitting layer is particularly preferably a molecular deposition film. Here, the molecular deposition film is a thin film formed by deposition from a material compound in a gaseous state or a film formed by solidification from a material compound in a solution state or a liquid phase state. Is
It can be distinguished from a thin film (molecule accumulation film) formed by the LB method by a difference in an aggregated structure and a higher-order structure and a functional difference caused by the difference. Also, Japanese Patent Application Laid-Open No. 57-517
As disclosed in Japanese Patent Publication No. 81, after a binder such as a resin and a material compound are dissolved in a solvent to form a solution, the solution is formed into a thin film by a spin coating method or the like to form a light emitting layer. be able to. The thickness of the light emitting layer formed in this manner is not particularly limited and can be appropriately selected depending on the circumstances. Usually, the thickness is preferably in the range of 5 nm to 5 μm. The light emitting layer of the organic EL element has the following functions. That is, an injection function; a function of injecting holes from an anode or a hole injection layer when an electric field is applied, and a function of injecting electrons from a cathode or an electron injection layer; a transport function; injected charges (electrons and holes ) By a force of an electric field and a light-emitting function; a function of providing a field for recombination of electrons and holes and linking it to light emission. However, there may be a difference between the ease with which holes are injected and the ease with which electrons are injected, and the transportability, which is represented by the mobility of holes and electrons, may be large or small. It is preferable to move.

(2) -3. Hole Injection Layer Next, the hole injection layer is not always necessary for the device used in the present invention, but is preferably used for improving light emitting performance. This hole injection layer is a layer that assists hole injection into the light emitting layer, has a large hole mobility,
The ionization energy is usually as low as 5.5 eV or less.
As such a hole injecting layer, a material that transports holes to the light emitting layer with a lower electric field is preferable, and the mobility of holes is at least 10 ⁴ to 10 ⁶ V / cm when an electric field is applied. ^-6 cm ² / V · sec is more preferable.
Such a hole injecting material is not particularly limited as long as it has the above-mentioned preferable properties. Conventionally, in a photoconductive material, a material commonly used as a charge transporting material for holes or a positive electrode material of an EL element is used. Any one of known materials used for the hole injection layer can be selected and used.

As specific examples, for example, triazole derivatives (see US Pat. No. 3,112,197), oxadiazole derivatives (see US Pat. No. 3,189,447), imidazole derivatives (Japanese Patent Publication No. 37-1
No. 6096), polyarylalkane derivatives (U.S. Pat. Nos. 3,615,402 and 3,82).
Nos. 0,989, 3,542,544, JP-B-45-555, JP-B-51-10983, JP-A-51-93224, and 55-171.
Nos. 05, 56-4148, 55-108
Nos. 667 and 55-15653 and 56-
No. 36656), pyrazoline derivatives and pyrazolone derivatives (U.S. Pat. Nos. 3,180,729 and 4,278,746; JP-A-55-8).
Nos. 8064, 55-88065, 49-
Nos. 105537, 55-51086 and 5
Nos. 6-80051, 56-88141, 57-54545, 54-112637 and 55-74546, and phenylenediamine derivatives (US Pat. No. 3,615,404). Specification, JP-B-51-10105, 46-3712
JP-A-47-25336, JP-A-54-53
No. 435, No. 54-110536, No. 54-
No. 119925), arylamine derivatives (U.S. Pat. Nos. 3,567,450 and 3,1).
Nos. 80,703, 3,240,597, 3,658,520 and 4,23
2,103, 4,175,961, 4,012,376, JP-B-49-3
5702, 39-27577 and JP-A-5
JP-A-5-144250, JP-A-56-119132, JP-A-56-22437, West German Patent No. 1,11
0,518), amino-substituted chalcone derivatives (see US Pat. No. 3,526,501),
Oxazole derivatives (as disclosed in U.S. Pat. No. 3,257,203), styryl anthracene derivatives (see JP-A-56-46234, etc.), and fluorenone derivatives (see JP-A-54-110837, etc.) ),
Hydrazone derivatives (US Pat. No. 3,717,462, JP-A-54-59143, and JP-A-55-520)
Nos. 63, 55-52064 and 55-46.
760, 55-85495, 57-1
1350, 57-148749, JP-A-2-311591, etc.), stilbene derivatives (JP-A-61-210363, 61-2284)
No. 51, No. 61-14642, No. 61-72
No. 255, No. 62-47646, No. 62-3
Nos. 6,674, 62-10652 and 62-
Nos. 30255, 60-93445 and 60
JP-A-94462, JP-A-60-174747, JP-A-60-175052, etc.), silazane derivatives (U.S. Pat. No. 4,950,950), polysilanes (JP-A-2-204996), Aniline copolymer (JP-A-2-282263), JP-A-1-
Conductive polymer oligomers (especially thiophene oligomers) disclosed in Japanese Patent Application Laid-Open No. 211399 can be used. As the material for the hole injection layer, those described above can be used.
No. 2,965,965), aromatic tertiary amine compounds and styrylamine compounds (U.S. Pat. No. 4,127,412, JP-A-53-27033).
JP-A-54-58445, JP-A-54-1496
Nos. 34, 54-64299, 55-79
No. 450, No. 55-144250, No. 56-
JP-A-119132, JP-A-61-295558, JP-A-61-98353, JP-A-63-295695, etc.), and particularly, an aromatic tertiary amine compound is preferably used. Further, it has two fused aromatic rings described in US Pat. No. 5,061,569 in a molecule,
For example, 4,4'-bis [N- (1-naphthyl) -N-
Phenylamino] biphenyl (hereinafter abbreviated as NPD) and 4,4 ′, 4 ″ -tris in which three triphenylamine units described in JP-A-4-308688 are connected in a starburst form. [N- (3-
Methylphenyl) -N-phenylamino] triphenylamine (hereinafter abbreviated as MTDATA) and the like. Further, in addition to the above-mentioned aromatic dimethylidin-based compound shown as the material of the light emitting layer, p-type Si, p-type Si
An inorganic compound such as C can also be used as a material for the hole injection layer. The hole injection layer can be formed by thinning the above-mentioned compound by a known method such as a vacuum evaporation method, a spin coating method, a casting method, and an LB method. The thickness of the hole injection layer is not particularly limited, but is usually 5 nm to 5 μm. This hole injection layer is
It may be composed of one or more of the above-mentioned materials, or may be a layer obtained by laminating a hole injection layer made of a compound different from the hole injection layer. Further, the organic semiconductor layer is a layer that assists hole injection or electron injection into the light emitting layer, and preferably has a conductivity of 10 ⁻¹⁰ S / cm or more. As a material for such an organic semiconductor layer, a conductive oligomer such as a thiophene-containing oligomer or an arylamine-containing oligomer, or a conductive dendrimer such as an arylamine-containing dendrimer can be used.

(2) -4 Electron Injecting Layer On the other hand, the electron injecting layer is a layer that assists the injection of electrons into the light emitting layer, has a high electron mobility, and the adhesion improving layer is one of the electron injecting layers. In particular, a layer made of a material having good adhesion to the cathode. Preferred examples of the material used for the electron injection layer include a metal complex of 8-hydroxyquinoline or a derivative thereof, or an oxadiazole derivative. As a material used for the adhesion improving layer, a metal complex of 8-hydroxyquinoline or a derivative thereof is particularly suitable. Specific examples of the metal complex of 8-hydroxyquinoline or a derivative thereof include a metal chelate oxinoid compound containing a chelate of oxine (generally, 8-quinolinol or 8-hydroxyquinoline). For example, Alq described in the light-emitting layer can be used. On the other hand, as oxadiazole derivatives,
General formulas (II), (III) and (IV)

[0044]

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(Wherein Ar ^{10 to} Ar ¹³ each represent a substituted or unsubstituted aryl group, and Ar ¹⁰ , Ar ¹¹ and A
r ¹² and Ar ¹³ may be the same or different, and each represents an Ar ¹⁴ substituted or unsubstituted arylene group. )). Here, the aryl group includes a phenyl group, a biphenyl group, an anthranyl group, a perylenyl group, a pyrenyl group, and the like. Can be Also,
As the substituent, an alkyl group having 1 to 10 carbon atoms, 1 carbon atom
And 10 to 10 alkoxy groups or cyano groups. The electron transfer compound is preferably a thin film-forming compound. Specific examples of the electron transfer compound include the following.

[0046]

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(2) -5. Cathode As the cathode, a metal with a small work function (4 eV or less)
An alloy, an electrically conductive compound, and a mixture thereof are used as electrode materials. Specific examples of such electrode materials include sodium, sodium-potassium alloy,
Examples include magnesium, lithium, magnesium / silver alloy, aluminum / aluminum oxide (Al ₂ O ₃ ), aluminum / lithium alloy, indium, and rare earth metals. The cathode is formed by depositing these electrode materials by vapor deposition, sputtering, CVP, ion plating,
It can be manufactured by forming a thin film by a method such as an electrodeposition method, an electroplating method, and a chemical plating method. Further, the sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually 10 nm to 100 μm in the present invention.
m, preferably from 100 nm to 10 μm, more preferably from 200 nm (0.2 μm) to 2 μm. In this case, it is easier to reduce the upper limit in processing as the definition of the cathode pattern increases. However, in view of lower power consumption of the organic EL light emitting device (lower resistance of the electrode), the upper limit is particularly limited. More preferably, the thickness is 0.2 μm or more. In the EL element used in the present invention, it is preferable that one of the anode and the cathode is transparent or translucent, since light is transmitted therethrough and light emission extraction efficiency is high.

(2) -6. Fabrication of Organic EL Element (Example) An anode, a light emitting layer, a hole injection layer, if necessary, and an electron injection layer, if necessary, are formed by the materials and methods exemplified above. An EL element can be manufactured. Further, the organic EL device can be manufactured in the reverse order from the cathode to the anode.

An organic E having a structure in which an anode / a hole injection layer / a light emitting layer / an electron injection layer / a cathode is sequentially provided on a support substrate is described below.
An example of manufacturing an L element will be described. First, on an appropriate substrate, a thin film made of an anode material is 1 μm or less, preferably 10 to 2 μm.
An anode is formed by a method such as vapor deposition or sputtering so as to have a thickness in the range of 00 nm. Next, a hole injection layer is provided on the anode. The formation of the hole injection layer
As described above, it can be performed by a method such as a vacuum deposition method, a spin coating method, a casting method, and an LB method. However, from the viewpoint that a uniform film is easily obtained and pinholes are hardly generated, the vacuum deposition method It is preferable to form with.
When the hole injection layer is formed by a vacuum evaporation method, the deposition conditions vary depending on the compound to be used (the material of the hole injection layer), the crystal structure and the recombination structure of the target hole injection layer, etc. Deposition source temperature 50 to 450 ° C, degree of vacuum 10 ^-7 to
10 ^-3 torr, deposition rate 0.01 to 50 nm / se
c, the substrate temperature is preferably -50 to 300 ° C., and the film thickness is preferably selected in the range of 5 nm to 5 μm.

Next, a light emitting layer in which a light emitting layer is provided on the hole injection layer is also formed by a vacuum evaporation method using a desired organic light emitting material.
It can be formed by thinning the organic light-emitting material by a method such as sputtering, spin coating, or casting, but is formed by a vacuum evaporation method because a uniform film is easily obtained and pinholes are hardly generated. Is preferred. When the light emitting layer is formed by a vacuum evaporation method, the evaporation conditions vary depending on the compound used, but can be generally selected from the same condition range as the hole injection layer.

Next, an electron injection layer is provided on the light emitting layer. Like the hole injection layer and the light emitting layer, it is preferable to form the film by a vacuum deposition method from the viewpoint of obtaining a uniform film. The deposition conditions can be selected from the same condition range as the hole injection layer and the light emitting layer.

Finally, an organic EL device can be obtained by laminating cathodes. The cathode is made of metal,
Evaporation and sputtering can be used. However, to protect the underlying organic layer from damage during film formation,
Vacuum evaporation is preferred.

In the production of the organic EL device described so far, it is preferable to produce the anode to the cathode consistently by one evacuation.

When a DC voltage is applied to the organic EL device, light emission can be observed when a voltage of 5 to 40 V is applied with the anode having a positive polarity and the cathode having a negative polarity. Even if a voltage is applied in the opposite polarity, no current flows and no light emission occurs. Further, when an AC voltage is applied, uniform light emission is observed only when the anode has a positive polarity and the cathode has a negative polarity. The waveform of the applied alternating current may be arbitrary. Here, in order to manufacture an organic EL element that emits light while being separated and arranged in a plane,
An XY dot matrix system in which a stripe-shaped anode pattern and a cathode pattern intersect, a DC voltage is applied to each electrode to emit light at the intersection, and either the anode or the cathode is formed in a dot shape, and the TFT (Thin) is formed. Fil
m Transister) to apply a DC voltage only to a specific dot portion with a switching element to emit light. The stripe-shaped or dot-shaped anode pattern and cathode pattern can be formed by etching or lift-off by photolithography, or by masking deposition.

In particular, JP-A-5-299176 and JP-A-5-217676 disclose that the side surfaces of the anode or cathode electrode pattern (lower electrode pattern) are gradually or stepwise inclined toward the light-transmitting substrate. As disclosed in the official gazette or the like, the electrode material can be formed by controlling the etching conditions of the electrode or by increasing the distance between the translucent substrate and the mask during masking vapor deposition.

(3) Reflective Layer The reflective layer of the present invention may be any layer provided on at least the side surface of the lower electrode pattern and reflecting light in the visible region having a wavelength of 400 to 700 nm. The reflectance is usually 10% or more,
It is preferably at least 50%, more preferably at least 80%. Ag, Al, Au, C
u, Fe, Ge, In, K, Mg, Ba, Na, Ni,
Pb, Pt, Si, Sn, W, Zn, Cr, Ti, M
o, one or more metals or alloys such as stainless steel. Further, oxide nitrides, sulfides, nitrates, sulfates, and the like of the above metals may be used, and carbon may be contained as necessary. For example, MgO, TiO ₂ , BaSO _{4 and the} like can be mentioned. The material may be used as a film as it is as a reflection layer, or the material may be finely divided and dispersed in an appropriate binder resin to form a reflection layer. Table 1 shows the film surface reflectances of the main materials.

[0057]

[Table 1] ─────────────────────────────────── Metal reflectance (wavelength / nm) Metal reflectance (Wavelength / nm) Ag 97.9% (500) Na 98 0.2% (546) Al 91.6% (546) Ni 54.6% (440) Au 50.4% (500) Ni 60.7% (540) Cu 62.5% (500) Pb 67.5 % (700) Fe 60.7% (570) Pt 59.1% (589) Ge 46.6% (516) Si 37.5% (515) In 51.5% (500) W 43.1% ( 472) K 88.6% (546) Zn 82.5% (545) Mg 84.3% (546) ───────────────

The reflectivity of these metals is limited to a certain wavelength, but does not significantly change in the wavelength range of 400 to 700 nm. The effect of the reflective layer increases as the thickness of the lower electrode increases, and is preferably 0.2 μm.
m or more, more preferably 0.5 μm or more. The thickness of the reflective layer is not particularly limited as long as the function of reflecting light in the visible region having a wavelength of 400 to 700 nm at a desired reflectance is not impaired.

(4) Flattening Layer The flattening layer of the present invention is filled in the gap between the lower electrode patterns having the reflective layers on the side surfaces, and the unevenness formed by the lower electrode and the gap is alleviated, thereby flattening. I do. The material of the flattening layer may be the material described for the reflective layer, or the following resin layer. Examples of the resin layer include a cured product of a resin having an acrylate-based or methacrylate-based reactive vinyl group, such as a photocurable resin and / or a thermosetting resin. In addition, melamine resin, phenol resin, alkyd resin, epoxy resin, polyurethane resin, polyester resin, maleic acid resin, polyamide resin monomer, oligomer, polymer, polymethyl methacrylate, polyacrylate, polycarbonate, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyethyl cellulose And transparent resins such as carboxymethyl cellulose. Further, various fluoropolymers can also be mentioned. These resins can be used as the above-mentioned reflective material or as a binder resin of a light-shielding material described later.

In the case of forming a metal oxide layer, specifically, silicon oxide (SiO ₂ ), aluminum oxide (Al
₂ O ₃ ), titanium oxide (TiO ₂ ), yttrium oxide (Y ₂ O ₃ ), germanium oxide (GeO ₂ ), zinc oxide (ZnO), magnesium oxide (MgO), calcium oxide (CaO), boric acid (B ₂ O ₃ ), strontium oxide (SrO), barium oxide (BaO), lead oxide (PbO), zirconia (ZrO ₂ ), sodium oxide (Na ₂ O), lithium oxide (Li ₂ O), potassium oxide (K ₂ O) ) And thallium oxide (Ta ₂ O ₅ ). As the nitride layer, silicon nitride (S
i ₃ N ₄ ).

It is necessary that at least one of the above-mentioned reflective layer and the flattening layer is electrically insulating. The resistivity is 10 ⁶ Ω · cm or more, preferably 10 ⁹
Ω · cm or more. If it is less than 10 ⁶ Ω · cm, electrical conduction (short circuit) occurs between the lower electrodes, which causes display defects of the organic EL light emitting device.

The light transmittance of the reflective layer and / or the planarizing layer in the visible region having a wavelength of 400 to 700 nm is preferably 10% or less, more preferably 1% or less. If it exceeds 10%, the light from the organic material layer and the light from the gap between the upper electrode patterns cannot be sufficiently blocked, and it is not sufficient to obtain a display with good contrast.

As specific materials, in addition to the above materials,
Various pigments such as carbon black, titanium black, and aniline black may be included in the material of the reflective layer or the insulating layer, or simply dispersed in a binder resin,
There is no particular limitation as long as the above function is satisfied.

When the reflective layer or the planarizing layer is made of a material such as a metal, a metal oxide, or a metal nitride, the same as the lower electrode, the vapor deposition method, the sputtering method, the CVD method, the ion plating method, Films are formed by deposition, electroplating, and chemical plating, and they are etched or lifted off by photolithography to selectively arrange them on the side surfaces of the lower electrode pattern in a desired pattern, or to fill gaps in the lower electrode pattern. can do.

In the case of a resin pigment, spin coating,
Forming a film by a method such as roll coating or casting, patterning or etching using a photolithography method, and selectively disposing a desired pattern on the side surface of the lower electrode pattern or filling a gap between the lower electrode patterns. Can be. Also, instead of photolithography, screen printing, printing methods such as offset printing,
A direct reflection layer or a planarization layer can be formed. In particular, as a simple method of forming the reflective layer and the flattening layer, when the conductive reflective layer 5 is formed in the gap between the lower electrode patterns, in order to take insulation between the lower electrode patterns 2, There is a method of selectively performing electrochemical anodic oxidation on the intermediate portion of the layer, or performing a method such as oxygen plasma to insulate the metal (FIG. 5). At this time, since the reflective layer is conductive, the reflective layer can also serve as an auxiliary electrode for lowering the resistance value of the lower electrode. In order to further flatten the unevenness of the lower electrode pattern and the gap therebetween, a method of polishing the surface after filling the reflective layer or the flattening layer may be mentioned.

[0066]

EXAMPLES The present invention will be described more specifically with reference to the following examples.

[Example 1] 100 mm as a light-transmitting substrate
A lower electrode (anode) of ITO (indium tin oxide) having a thickness of 0.20 μm and a surface resistance of 15Ω / □ was formed on a glass substrate (Corning 7059) having a thickness of 100 mm × 1.1 mm by sputtering. Next, a positive photoresist (HPR204 manufactured by Fuji Hunt Electronics Technology) was spin-coated on the ITO, and 8
After baking at 0 ° C., 250 μm line 5
Exposure was performed at 100 mJ / cm ² through a mask capable of obtaining a stripe-shaped resist pattern having a gap of 0 μm.
Next, the resist is developed with a 2.38% aqueous solution of TMAH (tetramethylammonium hydroxide),
Was performed to form a resist pattern. Next, the substrate was immersed in a 47% aqueous solution of hydrobromic acid, and the exposed ITO was etched. Next, Ag (silver) was deposited to a thickness of 0.20 μm by vapor deposition and laminated, the resist was peeled off with a peeling liquid (N303 manufactured by Nagase & Co., Ltd.), and the Ag on the lower electrode was lifted off. As a result, a substrate was obtained in which the gap between the lower electrode patterns was filled with silver. Next, a positive photoresist (described above) is spin-coated on the substrate,
After baking at 0 ° C., 280 μm line 2
Exposure was performed at 100 mJ / cm ² , in alignment with the lower electrode pattern, through a mask that provided a stripe-shaped resist pattern with a gap of 0 μm. Next, 2.38%
The resist was developed with a TMAH aqueous solution and post-baked at 130 ° C. to form a resist pattern. Next, the substrate was immersed in an etchant composed of 40 g of chromic anhydride, 20 ml of concentrated sulfuric acid, and 2 liters of pure water to etch the exposed Ag, and stripped the resist as before. Here, the substrate fabricated under the same conditions was cross-section SEM (Scan
Observation by ning electron microscopy) revealed that the side surfaces of the pattern of the lower electrode were almost vertical, and that Ag of the reflective layer was arranged on the side surfaces on both sides of the lower electrode pattern with a width of 15 μm. Further, even when the Ag film had a thickness of 0.20 μm, the transmittance of light in a visible region having a wavelength of 400 to 700 nm was 10% or less according to a spectrophotometer. Next, the substrate was subjected to IPA cleaning and UV cleaning, and then fixed to a substrate holder of a vapor deposition device (manufactured by Nippon Vacuum Technology). The evaporation source was a molybdenum resistance heating boat with MT as a hole injection material.
DATA and NPD, DPVBi as a light emitting material, DPAVB as a dopant, and Alq as an electron injecting material, respectively, Ag as a second metal of a cathode, a tungsten filament, and M as an electron injecting metal of a cathode.
g was mounted on a molybdenum boat. Thereafter, the pressure in the vacuum chamber was reduced to 5 × 10 ⁻⁷ torr, and the layers were sequentially laminated in the following order. The vacuum was not broken on the way from the hole injecting layer to the cathode, but was performed by one evacuation. First, as the hole injection layer,
MTDATA is deposited at a deposition rate of 0.1 to 0.3 nm / s, film thickness is 200 nm, and NPD is deposited at a deposition rate of 0.1 to 0.3 nm / s.
s, a film thickness of 20 nm, and as a light emitting layer, DPVBi was deposited at a deposition rate of 0.1 to 0.3 nm / s, and DPAVB was deposited at a deposition rate of 0.1 nm.
Simultaneous vapor deposition at 05 nm / s and a total thickness of 40 nm (the weight ratio of dopant to host material is 1.2 to 1.6)
As the electron injection layer, Alq is deposited at a deposition rate of 0.1 to
0.3 nm / s, 20 nm in film thickness, Mg and Ag are used as upper electrodes (cathodes) through a mask which is perpendicular to the lower electrode (anode) stripe pattern and has a stripe pattern of 600 μm line and 100 μm gap.
Was co-evaporated. That is, Mg is deposited at a rate of 1.3 to 1.3.
1.4 nm / s and Ag were 200 nm in film thickness at a deposition rate of 0.1 nm / s. In this way, an organic EL light emitting device is manufactured (FIG. 1), and when a voltage of 8 V DC is applied to the anode and the cathode, the intersection of the anode and the cathode to which the voltage is applied emits light, and the luminance distribution of the entire light emitting device and CIE chromaticity coordinates (JIS Z 8701) are 100 ± 10 cd each
/ M ² , chromaticity x = 0.16, y = 0.24, blue light emission was obtained, and an organic EL light emitting device with less light bleeding was obtained.

Example 2 100 mm as Translucent Substrate
A lower electrode (anode) of ITO (indium tin oxide) having a thickness of 0.20 μm and a surface resistance of 15Ω / □ was formed on a glass substrate (Corning 7059) having a thickness of 100 mm × 1.1 mm by sputtering. Next, a positive photoresist (described above) was spin-coated on the ITO and air-dried at room temperature.
Exposure was performed at 100 mJ / cm ² through a mask capable of obtaining a striped resist pattern with m gaps. Next, the resist was developed with a 2.38% TMAH aqueous solution to form a resist pattern. Hereinafter, the ITO was etched under the same conditions as in Example 1 to perform Ag film formation, lift-off, resist patterning, Ag etching, and resist peeling. Here, when the substrate manufactured under the same conditions was observed with a cross-sectional SEM, the side surfaces on both sides of the pattern of the lower electrode gradually or stepwise expanded toward the light-transmitting substrate (in a tapered shape). A), and the taper angle is 1
It was 0.5 degrees. Also, one side of the lower electrode pattern
Ag of the reflective layer was arranged with a width of 5 μm. According to the spectrophotometer, even if the Ag film has a thickness of 0.20 μm,
The light transmittance in the visible region with a wavelength of 400 to 700 nm was 10% or less. Hereinafter, an organic EL light emitting device was manufactured under the same conditions as in Example 1 (FIG. 2). When a voltage of 8 V DC was applied to the anode and the cathode, the intersection of the anode and the cathode to which the voltage was applied emitted light, and the light emitting device was manufactured. Overall luminance distribution and CI
E chromaticity coordinates (JIS Z 8701) are each 120
± 10 cd / m ² , chromaticity x = 0.16, y = 0.24
Blue light was emitted before and after with higher luminance than in Example 1, and an organic EL light emitting device with less light bleeding was obtained.
In addition, light emission defects such as crosstalk were reduced as compared with the first embodiment.

[Embodiment 3] A light-transmitting substrate of 100 mm
A lower electrode (anode) of ITO (indium tin oxide) having a thickness of 0.20 μm and a surface resistance of 15Ω / □ was formed on a glass substrate (Corning 7059) having a thickness of 100 mm × 1.1 mm by sputtering. Next, a positive photoresist (described above) is spin-coated on the ITO, and 8
After baking at 0 ° C., 250 μm line 5
Exposure was performed at 100 mJ / cm ² through a mask capable of obtaining a stripe-shaped resist pattern having a gap of 0 μm.
Next, the resist was developed with a 2.38% TMAH aqueous solution to form a resist pattern. Next, 47%
The exposed ITO was immersed in a hydrobromic acid aqueous solution to etch the exposed ITO. Next, Al (aluminum) is vapor-deposited in 0.1.
A film having a thickness of 20 μm was formed and laminated, and aluminum on the lower electrode pattern was lifted off. As a result, a substrate in which the gap between the lower electrode patterns was filled with Al was obtained. Next, a positive photoresist (described above) is spin-coated on the substrate and baked at 80 ° C.
Exposure was performed at 100 mJ / cm ² in alignment with the lower electrode pattern through a mask capable of obtaining a striped resist pattern having a 20 μm gap with a μm line. Next, the resist is developed with a 2.38% TMAH aqueous solution,
Post-baking was performed at 130 ° C. to form a resist pattern. Next, a 0.1 mol / l aqueous solution of ammonium tartrate and ethylene glycol were mixed at a volume ratio of 1: 9, and a small amount of an aqueous ammonia solution was added thereto to prepare a chemical solution whose pH was adjusted to 7.0. The substrate was immersed in a chemical conversion solution with the anode as the anode and the platinum mesh as the cathode, and the exposed aluminum was anodized. In addition, the voltage is 1 m up to 200 V.
The temperature of the chemical conversion solution was maintained at 40 to 50 ° C. by gradually applying while controlling the constant current of A / cm ² . After confirming that almost no current flows, remove the resist (see above)
Peeled off. Here, the substrate fabricated under the same conditions was
Observation by EM revealed that the side surfaces of the pattern of the lower electrode were almost vertical, and aluminum of a reflective layer was disposed with a width of 15 μm on both side surfaces of the lower electrode pattern, and Al ₂ O ₃ was placed between the reflective layers. A (aluminum oxide) planarization layer was filled. As a result, unevenness due to the lower electrode pattern and the gap was flattened (FIG. 5). In addition, this Al
According to the spectrophotometer, even if the film has a thickness of 0.20 μm, the light transmittance in the visible region of a wavelength of 400 to 700 nm is 1
0% or less. Hereinafter, an organic EL light emitting device was manufactured under the same conditions as in Example 1 (FIG. 3). When a voltage of DC 8 V was applied to the anode and the cathode, the intersection of the anode and the cathode to which the voltage was applied emitted light, and the light emitting device was manufactured. The overall luminance distribution and CIE chromaticity coordinates (JIS Z 8701) are 100 ± 1 respectively.
At 0 cd / m ² , chromaticity of x = 0.16 and y = 0.24, blue light emission was obtained, and an organic EL light emitting device with less light bleeding was obtained. In addition, light emission defects such as crosstalk were reduced as compared with the first embodiment.

Example 4 100 mm as Translucent Substrate
A lower electrode (anode) of ITO (indium tin oxide) having a thickness of 0.20 μm and a surface resistance of 15Ω / □ was formed on a glass substrate (Corning 7059) having a thickness of 100 mm × 1.1 mm by sputtering. Next, a positive photoresist (described above) is spin-coated on the ITO, and 8
After baking at 0 ° C., 250 μm line 5
Exposure was performed at 100 mJ / cm ² through a mask capable of obtaining a stripe-shaped resist pattern having a gap of 0 μm.
Next, the resist was developed with a 2.38% TMAH aqueous solution to form a resist pattern. Next, 47%
The exposed ITO was immersed in a hydrobromic acid aqueous solution to etch the exposed ITO, and the resist was stripped with a stripping solution (N303 manufactured by Nagase & Co., Ltd.). Next, Cr (chromium) having a film thickness of 0.20 μm was formed by sputtering. Next, a positive photoresist (described above) was spin-coated on Cr, baked at 80 ° C., and then exposed to a 30 μm line at 270 μm using an exposure machine.
100 mJ / c through a mask in which a stripe-shaped resist pattern having a gap is obtained between the lower electrode patterns.
Exposure at m ² . Next, the resist was developed with a 2.38% TMAH aqueous solution to form a resist pattern. Next, 165 g of ceric ammonium nitrate was added to the substrate.
It was immersed in an etchant having a composition of 0% by weight of perchloric acid (42 ml) and pure water (1 liter), the exposed Cr was etched, and the resist was stripped with a stripping solution (described above). As a result, a substrate was obtained in which the gap between the lower electrode patterns was filled with Cr of the flattening layer.
A gap of about m is open. Next, spin coating was performed using an acrylate-based photocurable resist (V259PA manufactured by Nippon Steel Science Co., Ltd.) in which 30% by weight (based on solid content) of Al powder was dispersed, and baked at 80 ° C. Next, the substrate was set in an exposure machine using a high-pressure mercury lamp as a light source, and the position between the lower electrode and the planarizing layer was selectively set to 600 mJ / cm using a mask.
² (365 nm). Next, after developing with a 1% aqueous solution of sodium carbonate for 2 minutes at room temperature, baking was performed at 200 ° C. to form a reflective layer of an acrylic resin in which aluminum was dispersed in a gap between the lower electrode and the flattening layer. Further, the substrate surface was set on a tape polishing machine (SSP-400 manufactured by Sanshin),
Polishing was performed with a No. 0000 (mesh) polishing tape (wrapping film manufactured by Sumitomo 3M Limited). Here, when the substrate manufactured under the same conditions was observed by a cross-sectional SEM, the side surfaces of the pattern of the lower electrode were almost vertical, and the side surfaces of both sides of the lower electrode pattern had a width of 10 μm and the A
An acrylic resin in which 1 was dispersed was disposed, and a flattening layer of Cr was filled between the reflective layers. As a result, unevenness due to the lower electrode pattern and the gap was flattened. Further, according to the spectrophotometer, even in the case of the Cr film having a thickness of 0.20 μm, the transmittance of light in the visible region having a wavelength of 400 to 700 nm was 10% or less. Hereinafter, an organic EL light emitting device was manufactured under the same conditions as in Example 1 (FIG. 4), and a DC voltage of 8 V was applied.
Is applied to the anode and the cathode, the intersection of the anode and the cathode to which the voltage is applied emits light, and the luminance distribution and CIE chromaticity coordinates (JIS Z 8701) of the entire light emitting device are 100 ± 10 cd / m ² , respectively, The degree is x = 0.16, y =
Blue light emission was obtained at around 0.24. Here, since a light-shielding flattening layer was disposed, an organic EL light-emitting device without light bleeding could be obtained. In addition, light emission defects such as crosstalk were reduced as compared with the first embodiment.

[Example 5] 100 mm as a light-transmitting substrate
ITO (indium tin oxide) having a thickness of 0.50 μm and a surface resistance of 5Ω / □ on a glass substrate (Corning 7059) having a thickness of 100 mm × 1.1 mm by sputtering.
Was formed as a lower electrode (anode). Next, a positive photoresist (described above) is spin-coated on the ITO,
After baking in 250μm line 50μ
Exposure was performed at 100 mJ / cm ² through a mask capable of obtaining a striped resist pattern with m gaps. Next, the resist is developed with a 2.38% TMAH aqueous solution,
Post-baking was performed at 130 ° C. to form a resist pattern. Next, the substrate is immersed in a 47% aqueous solution of hydrobromic acid,
The exposed ITO was etched. Next, Ag was deposited to a thickness of 0.50 μm by vapor deposition and laminated, and the resist was peeled off with a peeling liquid (described above) to lift off the Ag on the lower electrode. As a result, a substrate in which the gap between the lower electrode patterns was filled with Ag was obtained. Next, a positive photoresist (described above) is spin-coated on the substrate, baked at 80 ° C., and then exposed with an exposure machine through a mask capable of obtaining a striped resist pattern having a 280 μm line and a 20 μm gap. 100mJ, aligned with the electrode pattern
/ Cm ² . Next, the resist is developed with a 2.38% TMAH aqueous solution and post-baked at 130 ° C.
A resist pattern was formed. Next, chromic anhydride 40
g, concentrated sulfuric acid 20 ml, and pure water 2 liter, the substrate was immersed in the etchant, the exposed Ag was etched, and the resist was stripped as before. Here, when the substrate manufactured under the same conditions was observed with a cross-sectional SEM,
The side surface of the pattern of the lower electrode was substantially vertical, and the Ag of the reflective layer was arranged with a width of 15 μm on both side surfaces of the lower electrode pattern. Hereinafter, the organic EL device was used under the same conditions as in Example 1.
When a light emitting device is manufactured (FIG. 1) and a voltage of 8 V DC is applied to the anode and the cathode, the intersection of the anode and the cathode to which the voltage is applied emits light, and the luminance distribution and CIE chromaticity coordinates (JIS Z 8701) is 110 ± 5 cd respectively.
/ M ² , chromaticity x = 0.16, y = 0.24, blue light emission was obtained, and an organic EL light emitting device with less light bleeding was obtained. In addition, since the thickness of the ITO film was increased to reduce the resistance value, an organic EL light emitting device having higher luminance than Example 1 and having less luminance unevenness could be obtained.

Comparative Example 1 An organic EL light emitting device (FIG. 7) was manufactured under the same conditions as in Example 1 except that no reflective layer was formed. DC 8
When a voltage of V is applied to the anode and the cathode, the intersection of the anode and the cathode to which the voltage is applied emits light, and the luminance distribution and CIE chromaticity coordinates (JIS Z 8701) of the entire light emitting device are 80 ± 10 cd / m ² , respectively. The chromaticity is x = 0.16, y =
Blue light emission was obtained around 0.24. However, since there is no reflective layer, the luminance is lower than that of Example 1, and
Light bleeding occurred, resulting in a display having lower contrast than that of Example 1.

[Comparative Example 2] 100 mm as a translucent substrate
A lower electrode (anode) of ITO (indium tin oxide) having a thickness of 0.20 μm and a surface resistance of 15Ω / □ was formed on a glass substrate (Corning 7059) having a thickness of 100 mm × 1.1 mm by sputtering. Next, a positive photoresist (described above) is spin-coated on the ITO, and 8
After baking at 0 ° C., 250 μm line 5
Exposure was performed at 100 mJ / cm ² through a mask capable of obtaining a stripe-shaped resist pattern having a gap of 0 μm.
Next, the resist was developed with a 2.38% TMAH aqueous solution and post-baked at 130 ° C. to form a resist pattern. Next, the substrate was immersed in a 47% aqueous solution of hydrobromic acid, and the exposed ITO was etched. Next, a light-shielding Ta ₂ O ₅ (thallium oxide) is formed into a film with a thickness of 0.20 μm by sputtering and laminated, and the resist is peeled off with a peeling liquid (N303 manufactured by Nagase & Co., Ltd.). the of Ta ₂ O ₅ which has a lifting off. As a result, a substrate in which the gap between the lower electrode patterns was filled with Ta ₂ O ₅ was obtained. Here, according to the spectrophotometer, even if the Ta ₂ O ₅ film has a thickness of 0.20 μm, the transmittance of light in a visible region of a wavelength of 400 to 700 nm was 10% or less. Hereinafter, an organic EL light emitting device was manufactured under the same conditions as in Example 1. This organic EL
When a voltage of DC 8 V is applied to the anode and the cathode of the light emitting device,
The intersection of the anode and the cathode to which the voltage was applied emits light, and the luminance distribution and CIE chromaticity coordinates (JIS Z
8701) is 80 ± 10 cd / m ² , and the chromaticity is x
Blue light emission was obtained around = 0.16 and y = 0.24. Since Ta ₂ O ₅ has a light-shielding property, light bleeding is small, but since there is no reflective layer, the luminance is lower than that of Example 1.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a first embodiment of the present invention.

FIG. 2 is a cross-sectional view schematically showing a second embodiment of the present invention.

FIG. 3 is a sectional view schematically showing a third embodiment of the present invention.

FIG. 4 is a cross-sectional view schematically showing a fourth embodiment of the present invention.

FIG. 5 is a sectional view showing step by step a method of forming a reflective layer and a planarizing layer used in the present invention.

FIG. 6 is an explanatory view showing a conventional organic EL light emitting device (XY dot matrix type).

FIG. 7 is a cross-sectional view showing a conventional organic EL light emitting device (using a transparent electrode as a lower electrode).

FIG. 8 is a cross-sectional view illustrating an example of a conventional inorganic EL light emitting device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 translucent substrate 2 lower electrode (pattern) 3 organic layer (light emitting layer) 4 upper electrode (pattern) 5 reflective layer 6 planarizing layer 7 reflective metal (conductive) 8 photoresist

Claims (5)

[Claims] 1. A lower electrode pattern on a transparent substrate,
In an organic EL light emitting device in which an organic material layer including a light emitting layer and an upper electrode pattern are sequentially laminated, a wavelength of 400 to 70 is applied to at least a side surface of the lower electrode pattern.
An organic EL light emitting device comprising a reflection layer for light in a visible region of 0 nm. 2. The organic EL light emitting device according to claim 1, wherein the cross-sectional shape of the lower electrode pattern is gradually or stepwise enlarged toward the light-transmitting substrate. 3. The organic EL light emitting device according to claim 1, wherein a gap between the lower electrode patterns is filled with a flattening layer so as to flatten irregularities due to the lower electrode pattern. 4. The reflective layer and / or the planarizing layer,
The organic EL light emitting device according to any one of claims 1 to 3, wherein light transmittance in a visible region having a wavelength of 400 to 700 nm is 10% or less. 5. The film thickness of the lower electrode pattern is 0.2
The organic EL light emitting device according to claim 1, wherein the thickness is at least μm.