JPH1012380A - Multicolor light emitting device and method of manufacturing the same - Google Patents

Abstract

(57) [Summary] [Object] To provide a multicolor light emitting device having excellent viewing angle characteristics, and to provide a method capable of easily and efficiently manufacturing the multicolor light emitting device. A first light-emitting pixel formed by sequentially laminating a first substrate electrode, an organic layer including a first light-emitting layer, and a first counter electrode is formed on a first transparent substrate.
A plurality of first organic EL elements 100 arranged regularly and separately from each other on the first substrate 1, an organic material layer including a second substrate electrode 202, and a second light emitting layer emitting a color different from the first light emitting layer 203, and a second organic EL element 200 in which a plurality of second luminescent pixels formed by sequentially laminating a second counter electrode 204 are arranged on the second transparent substrate 201 in a regular and separated manner from each other. The light emitted from the respective light emitting pixels are overlapped with each other via the transparent body 300 so as not to overlap each other in the light extraction direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multicolor light emitting device and a method for manufacturing the same. More particularly, the present invention relates to a multicolor light-emitting device suitably used for various light-emitting multicolor or full-color organic electroluminescence (EL) displays, and a method for manufacturing the same.

[0002]

2. Description of the Related Art EL devices have the characteristics of high visibility due to self-luminescence and excellent impact resistance due to complete solidity. At present, various EL devices using inorganic or organic compounds for the light-emitting layer are known. An element has been proposed and put to practical use.
As one of such practical applications, a multi-color light emitting device suitable for a multi-color and full-color EL display using an EL element can be given. As such a multicolor light emitting device, for example, the following is proposed. (1) An RGB multi-color display in which three light-emitting cells each displaying one of red, green and blue are bonded (Japanese Patent Application Laid-Open Nos. 7-58773 and 7-114350). Organic EL display for displaying two colors on a single substrate (European Patent Publication EP 0550062)
A2) (3) A material using a high-luminance, high-efficiency blue light-emitting material, a green light-emitting material, and an orange light-emitting material as a light-emitting material (US Pat. Nos. 5,130,603 and 476).
No. 9292)

[0003]

However, the above-described multicolor light emitting device has the following problems. (1) Japanese Unexamined Patent Publication No. 7-58773, etc.
Since the red, blue, and green light emission images are separated by the thickness of the substrate, the image position changes depending on the viewing angle, and good image display such as blurred images cannot be obtained. Further, three types of organic film formation and cathode film formation are required, and the process is complicated and costly. Further, the number of steps for mounting leads is tripled, which is complicated. (2) Those described in EP0550062A2 are red,
Since three colors of green and blue (R, G, B) cannot be emitted, a full-color display cannot be performed. (3) In the description of US Pat. No. 5,130,603 or the like, there is no reference to a good red light emitting material, and high luminance and high efficiency red light emission cannot be realized. Note that providing red, green, and blue (R, G, B) light-emitting pixels on a single substrate is extremely difficult because the light-emitting layer is extremely difficult to process by a photolithographic method. At present, a color light emitting display cannot be obtained. The present invention has been made in view of the above problems, and provides a multicolor light-emitting device having excellent viewing angle characteristics, and a method capable of easily and efficiently manufacturing the multicolor light-emitting device. With the goal.

[0004]

According to the present invention, in order to achieve the above object, a first substrate electrode, an organic layer including a first light emitting layer, and a first counter electrode are sequentially laminated. A first organic EL element in which a plurality of first luminescent pixels are regularly and separately arranged on a first transparent substrate, and emits a different color from the second substrate electrode and the first luminescent layer. A second light-emitting pixel formed by sequentially laminating an organic material layer including a second light-emitting layer, and a second counter electrode, a plurality of second light-emitting pixels arranged regularly and separately from each other on a second transparent substrate. Organic E
A multicolor light-emitting device is provided, wherein an L element is overlapped with a light-emitting pixel so that light emitted from each light-emitting pixel does not overlap with each other in a light extraction direction, and a transparent body is provided therebetween. .

In a preferred embodiment, at least one of the first luminescent pixel and the second luminescent pixel includes:
A multicolor light-emitting device is provided that includes a light-emitting layer that emits two or more types of light.

Further, in a method of manufacturing a multicolor light emitting device in which a plurality of light emitting pixels are separately arranged on a substrate,
(1) A first substrate electrode, an organic material layer including a first light emitting layer, and a first counter electrode are sequentially laminated on a first transparent substrate to form a plurality of first first electrodes separated regularly and mutually. Forming a first organic EL element having luminescent pixels, (2) including, on a second transparent substrate, a second substrate electrode and a second luminescent layer emitting a color different from the first luminescent layer; An organic material layer and a second counter electrode are sequentially laminated to form a second organic EL element having a plurality of second light-emitting pixels regularly and separated from each other. Manufacturing a multicolor light emitting device, wherein a second organic EL element is overlapped with a second organic EL element via a transparent member so that light emitted from the respective light emitting pixels does not overlap with each other in a light extraction direction. A method is provided.

[0007]

Embodiments of the present invention will be specifically described below with reference to the drawings. 1. 1. Multicolor Light Emitting Device (1) Outline of Configuration FIG. 1 is a sectional view schematically showing one embodiment of the multicolor light emitting device of the present invention. As shown in FIG. 1, the multicolor light-emitting device of the present invention has a configuration in which a first organic EL element 100 and a second organic EL element 200 are superposed on each other with a transparent body 300 interposed therebetween. I have. That is, the first organic E
In the L element 100, the first luminescent pixel has a first substrate electrode 102, an organic layer 103 including a first luminescent layer, and a first counter electrode 104 sequentially laminated on a first substrate 101. Thus, they are formed regularly and separated from each other. Further, in the second organic EL element 200, the second luminescent pixel is formed on the second transparent substrate 201 by the second substrate electrode 202 and the organic material layer 20 including the second luminescent layer.
The third and second counter electrodes 204 are sequentially laminated to form a regular and separated state. The two elements 100 and 200 are configured so as to overlap with each other via a transparent body 300 so that the light emitted from the light emitting pixels does not overlap each other in the light extraction direction.

Here, in the first organic EL device shown in FIG. 1, a device that emits blue light is used as the first light emitting layer. Light-emitting pixels having a light-emitting layer that emits blue light are arranged in a stripe shape or a mosaic shape. Thus, a first organic EL element having a blue light emitting pixel can be obtained.

Further, in the second organic EL element, an element emitting green light is used as the second light emitting layer.
Thus, the second organic EL having the green light emitting pixel
An element can be obtained. By overlapping the blue light emitting pixel display device comprising the first organic EL element and the green light emitting pixel display device comprising the second organic EL element,
Light is extracted from the outside of at least one of the substrates 101 or 201 to obtain a multicolor light-emitting device capable of multicolor pixel (image) display. The first or second substrate electrode may be either an anode or a cathode. Also, the first or second counter electrode may be either an anode or a cathode.

(2) Light-Emitting Pixel and its Arrangement Here, one light-emitting pixel includes one substrate electrode, one counter electrode, and an organic material layer including a light-emitting layer sandwiched therebetween. It is provided with a color filter and / or a color conversion medium layer as needed to realize a desired color, and means a portion where lighting and non-lighting can be controlled independently. Hereinafter, the case where the XY matrix is used will be described. An organic material layer is sandwiched between one substrate electrode line and one counter electrode line which are arranged so as to be orthogonal to each other.
In the present invention, if necessary, a color filter and a color conversion medium layer may be provided in the light extraction direction of the luminescent pixel.
The installation position may be between the transparent substrate and the substrate electrode line, or may be provided above the counter electrode line, but must be provided in the light extraction direction.

When such light emitting pixels are observed from the light extraction direction, a multicolor display having various light emitting pixel arrangements such as stripe arrangement and diagonal arrangement is obtained.

(3) Various Modifications FIG. 2 is a sectional view schematically showing another embodiment of the multicolor light emitting device of the present invention. In this example, the first organic EL element has a red light-emitting pixel, and the second organic EL element
The device has blue and green light emitting pixels. Similarly, in the example shown in FIG. 3, the first and second organic EL elements have red, blue, and green light emitting pixels, respectively.

(4) Components Transparent Substrate The transparent substrate used in the present invention is preferably a rigid material sufficient to support a multicolor light emitting device. In particular, when a high-definition display is performed, if the gap between the organic EL element and the phosphor layer is large, light emitted from the organic EL element is absorbed by the adjacent phosphor layer, and a desired emission color cannot be obtained. May be reduced. Therefore, it is necessary to reduce the thickness of the transparent insulating layer. However, if the thickness is reduced, the mechanical strength such as the impact resistance of the multicolor light emitting device is reduced.
In the present invention, the mechanical strength such as impact resistance is enhanced by reinforcing the multicolor light emitting device by disposing the transparent substrate.

Specific examples of the material include a glass plate, a ceramic plate, a plastic plate (polycarbonate, acrylic, vinyl chloride, polyethylene terephthalate, polyimide, polyester resin, etc.). The thickness of the substrate is not particularly limited, but for a multicolor light-emitting device that performs high-definition display, the formation of voids must be made high-definition. It is necessary to. Usually, it is in the range of 5 μm to 2 mm, preferably 50 μm to
1.1 mm. Organic EL Device In the organic EL device used in the present invention, an organic compound 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 compound layer. , An electron injection layer, an organic semiconductor layer, an electron barrier layer, an adhesion improving layer, and the like.

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. (1) Transparent electrode (anode) / light-emitting layer / electrode (cathode) (2) Transparent electrode (anode) / hole injection layer / light-emitting layer / electrode (cathode) (3) Transparent electrode (anode) / light-emitting layer / electron Injection layer / electrode (cathode) (4) Transparent electrode (anode) / hole injection layer / emission layer / electron injection layer / electrode (cathode) (5) anode / organic semiconductor layer / emission layer / cathode (6) anode / Organic semiconductor layer / Electron barrier layer / Emission layer / Cathode (7) Structures such as anode / hole injection layer / emission layer / adhesion improving layer / cathode. Of these, the configuration (4) is preferably used.

-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 transparent materials such as SnO ₂ and ZnO can be used. The anode can be manufactured by forming a thin film from these electrode substances by a method such as an evaporation method or a sputtering 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. The thickness of the anode depends on the material,
Usually 10 nm to 1 μm, preferably 10 to 200 nm
Is selected in the range. Note that, as described above, in the present invention, the electrode used as the anode is
It may be either a substrate electrode or a counter electrode.

-2. Light-Emitting Layer In the light-emitting layer of the present invention, a light-emitting material (host material) represented by the general formula (I)

[0018]

Embedded image

A distyryl arylene compound represented by the following formula is preferably used. This compound is disclosed in
No. 47278.

In the above general formula, each of Y ^{1 to} Y ⁴ is a hydrogen molecule, an alkyl group having 1 to 6 carbon atoms, and 1 to 6 carbon atoms.
An alkoxy group, an aralkyl group having 7 to 8 carbon atoms, a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, a substituted or unsubstituted cyclohexyl group, a substituted or unsubstituted aryloxy group having 6 to 18 carbon atoms , An alkoxy group having 1 to 6 carbon atoms. The substituent is an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 18 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. Aralkyl group, aryloxy group having 6 to 18 carbon atoms, acyl group having 1 to 6 carbon atoms, 1 carbon atom
Acyloxy group, carboxyl group, styryl group,
Arylcarbonyl group having 6 to 20 carbon atoms, 6 to 2 carbon atoms
0 represents an aryloxycarbonyl group, an alkoxycarbonyl group having 1 to 6 carbon atoms, a vinyl group, an anilinocarbonyl group, a carbamoyl group, a phenyl group, a nitro group, a hydroxyl group or a halogen. These substituents may be single or plural. Y ^{1 to} Y ⁴ may be the same or different from each other, and Y ¹ and Y ² and Y ³ and Y ⁴ are bonded to a mutually substituted group to form a substituted or unsubstituted saturated 5-membered ring. Alternatively, a substituted or unsubstituted saturated six-membered ring may be formed. Ar represents a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, which may be single-substituted or plurally-substituted;
Any meta may be used. However, when Ar is an unsubstituted phenylene group, Y ^{1 to} Y ⁴ are each an alkoxy group having 1 to 6 carbon atoms, an aralkyl group having 7 to 8 carbon atoms, a substituted or unsubstituted naphthyl group, a biphenyl group, a cyclohexyl group, They are selected from aryloxy groups. Examples of such a distilylylene-based compound include the following.

[0021]

Embedded image

[0022]

Embedded image

As another preferred light emitting material (host material), there can be mentioned a metal complex of 8-hydroxyquinoline or a derivative thereof. Specifically, it is a metal chelate oxanoid compound containing a chelate of oxine (generally 8-quinolinol or 8-hydroxyquinoline). Such compounds exhibit a high level of performance,
It is easily formed into a thin film form. Examples of the oxanoid compound satisfy the following structural formula.

[0024]

Embedded image

(Wherein, Mt represents a metal, and n is 1 to 3)
And Z represents an atom whose position is independent and which is necessary for completing at least two or more fused aromatic rings. Here, the metal represented by Mt can be a monovalent, divalent or trivalent metal, for example, an alkali metal such as lithium, sodium and potassium, and an alkaline earth metal such as magnesium and calcium. Or an earth metal such as boron or aluminum. Generally, any of the monovalent, divalent, or trivalent metals known to be useful chelating compounds can be used.

Z represents an atom in which at least one of two or more fused aromatic rings forms a heterocyclic ring composed of azole or azine. Here, if necessary, another different ring can be added to the fused aromatic ring. Further, in order to avoid bulky molecules without improving the function, it is preferable to keep the number of atoms represented by Z at 18 or less. Further, specific examples of chelated oxanoid compounds include tris (8-quinolinol).
Aluminum, bis (8-quinolinol) magnesium, bis (benzo-8-quinolinol) zinc, bis (2
-Methyl-8-quinolinolate) aluminum oxide, tris (8-quinolinol) indium, tris (5-methyl-8-quinolinol) aluminum, 8-
Quinolinol lithium, tris (5-chloro-8-quinolinol) gallium, bis (5-chloro-8-quinolinol) calcium, 5,7-dichloro-8-quinolinol aluminum, tris (5,7-dibromo-8-hydroxyquinolinol) ) Aluminum and the like.

Further, a metal complex of phenolate-substituted 8-hydroxyquinoline described in Japanese Patent Application Laid-Open No. 5-198338 is a preferable one as a blue light emitting material. Specific examples of the metal complex of the phenolate-substituted 8-hydroxyquinoline include bis (2-methyl-8-quinolinolate) (phenolate) aluminum (III),
Bis (2-methyl-8-quinolinolate) (o-cresolate) aluminum (III), bis (2-methyl-8
-Quinolinolate) (m-cresolate) aluminum (III), bis (2-methyl-8-quinolinolate)
(P-cresolate) aluminum (III), bis (2
-Methyl-8-quinolinolate) (o-phenylphenolato) aluminum (III), bis (2-methyl-8)
-Quinolinolate) (m-phenylphenolate) aluminum (III), bis (2-methyl-8-quinolinolate) (p-phenylphenolate) aluminum (III), bis (2-methyl-8-quinolinolate)
(2,3-dimethylphenolate) aluminum (II
I), bis (2-methyl-8-quinolinolate) (2,
6-dimethylphenolato) aluminum (III), bis (2-methyl-8-quinolinolate) (3,4-dimethylphenolate) aluminum (III), bis (2-methyl-8-quinolinolate) (3,5-dimethyl Phenolate) aluminum (III), bis (2-methyl-8)
-Quinolinolate) (3,5-di-t-butylphenolato) aluminum (III), bis (2-methyl-8-
(Quinolinolate) (2,6-diphenylphenolate) aluminum (III), bis (2-methyl-8-quinolinolate) (2,4,6-triphenylphenolate) aluminum (III), and the like. These luminescent materials may be used alone or in combination of two or more.

Hereinafter, a more specific description will be given. As the first light-emitting layer used in the present invention, various known light-emitting materials can be used.
The above-mentioned oxanoid compound may be a compound obtained by adding a small amount of a green fluorescent dye in an amount of 0.2 to 3% by weight. The green fluorescent dye added here is a coumarin type or a quinacridone type. By adding these, the element having the first light emitting layer can realize high efficiency green light emission of 5 to 20 (lm / w). On the other hand, when it is desired to extract yellow or orange from the first light emitting layer with high efficiency, an oxanoid compound obtained by adding rubrene and its derivative, a dicyanopyran derivative, and a perylene derivative in an amount of 0.2 to 3% by weight is used. These elements are 3 to 10 (lm /
It is possible to output light with high efficiency of w). In addition, orange color is possible even when a green fluorescent dye and a red fluorescent dye are simultaneously added. For example, preferably, coumarin and a dicyanopyran dye, quinacridone and a perylene dye, or coumarin and a perylene dye may be used simultaneously. Another particularly preferred first light emitting layer is a polyarylene vinylene derivative. This can output green or orange with high efficiency. As the second light emitting layer used in the present invention, various known blue light emitting materials can be used. For example, distyryl arylene derivatives, tristyryl arylene derivatives, and allyloxylated quinolylate metal complexes are high-level blue light-emitting materials. Examples of the polymer include a polyparaphenylene derivative.

As a method for forming the light emitting layer in the device used in the present invention, for example, a vapor deposition method, a spin coating method,
Although it can be formed by thinning by a known method such as a casting method and an LB method, a molecular deposition film is particularly preferable. Here, the molecular deposition film refers to a thin film formed by depositing the compound from a gaseous state or a film formed by solidifying the compound from a molten state or a liquid state. Usually, this molecular deposited film 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. Further, this light emitting layer can be formed by dissolving in a solvent together with a binder such as a resin to form a solution, and then thinning the solution by spin coating or the like. The thickness of the light emitting layer formed in this manner is not particularly limited and can be appropriately selected depending on the situation, but is preferably 1 nm to 10 μm, and particularly preferably 5 nm to 5 μm.

-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, for example, when an electric field of 10 ⁴ to 10 ⁶ V / cm is applied.
It is even more preferred that it be at least 10 ⁻⁶ cm ² / V · sec. 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, a triazole derivative (see US Pat. No. 3,112,197), an oxadiazole derivative (see US Pat. No. 3,189,447), an imidazole derivative (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 (those disclosed in U.S. Pat. No. 3,257,203), fluorenone derivatives (see JP-A-54-110837, etc.), and hydrazone derivatives (U.S. Pat. No. 3,717,462) , JP 54
-59143, 55-52063, 5
No. 5-52064, No. 55-46760, No. 55-85495, No. 57-11350,
JP-A-57-148749, JP-A-2-311591
And the like, styryl anthracene derivatives (see JP-A-56-46234 and the like), and stilbene derivatives (JP-A-61-210363 and 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. Representative examples of the porphyrin compound include porphine, 1,10,15,20-tetraphenyl-21H, 23H-porphine copper (II), 1,10,
15,20-tetraphenyl-21H, 23H-porphine zinc (II), 5,10,15,20-tetrakis (pentafluorophenyl) -21H, 23H-porphine, silicon phthalocyanine oxide, aluminum phthalocyanine chloride, phthalocyanine (metal-free ),
Examples thereof include dilithium phthalocyanine, copper tetramethyl phthalocyanine, copper phthalocyanine, chromium phthalocyanine, zinc phthalocyanine, lead phthalocyanine, titanium phthalocyanine oxide, Mg phthalocyanine, and copper octamethyl phthalocyanine. Representative examples of the aromatic tertiary amine compound and styrylamine compound include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl, N, N'-diphenyl-N, N'-bis- (3-methylphenyl)-[1,
1'-biphenyl] -4,4'-diamine (hereinafter TPD
, 2,2-bis (4-di-p-tolylaminophenyl) propane, 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane, N, N, N ',
N'-tetra-p-tolyl-4,4'-diaminophenyl, 1,1-bis (4-di-p-tolylaminophenyl) -4-phenylcyclohexane, bis (4-dimethylamino-2-methylphenyl ) Phenylmethane, bis (4-di-p-tolylaminophenyl) phenylmethane, N, N′-diphenyl-N, N′-di (4-methoxyphenyl) -4,4′-diaminobiphenyl, N,
N, N ', N'-tetraphenyl-4,4'-diaminophenyl ether, 4,4'-bis (diphenylamino) quadriphenyl, N, N, N-tri (p-tolyl) amine, 4- (Di-p-tolylamino) -4′-
[4 (di-p-tolylamino) styryl] stilbene,
4-N, N-diphenylamino- (2-diphenylvinyl) benzene, 3-methoxy-4′-N, N-diphenylaminostilbenzene, N-phenylcarbazole,
U.S. Pat. No. 5,061,569 which has two fused aromatic rings in the molecule, for example, 4,4'-
Bis [N- (1-naphthyl) -N-phenylamino] biphenyl (hereinafter abbreviated as NPD);
No. 308688, in which three triphenylamine units are linked in a starburst form,
4 ', 4 "-tris [N- (3-methylphenyl) -N
-Phenylamino] triphenylamine (hereinafter MTDA)
TA). In addition to the above-mentioned aromatic dimethylidin-based compound shown as the material of the light emitting layer, inorganic compounds such as p-type Si and p-type SiC can also be used as the material of 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.
m. The hole injection layer may be composed of one or more of the above-described materials, or may be a layer obtained by laminating a hole injection layer made of a compound different from the hole injection layer. It may be. 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 of such an organic semiconductor layer,
Conductive oligomers such as thiophene-containing oligomers and arylamine-containing oligomers, and conductive dendrimers such as arylamine-containing dendrimers can be used.

-4. Electron injection layer On the other hand, the electron injection layer is a layer that assists the injection of electrons into the light-emitting layer, and has a high electron mobility. It is a layer made of a material. 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. In addition, as a material used for the adhesion improving layer,
Particularly, a metal complex of 8-hydroxyquinoline or a derivative thereof is preferable. Specific examples of the metal complex of 8-hydroxyquinoline or a derivative thereof include a metal chelate oxanoid compound containing a chelate of oxine (generally, 8-quinolinol or 8-hydroxyquinoline). On the other hand, as oxadiazole derivatives, compounds represented by general formulas (II), (III) and (IV)

[0033]

Embedded image

(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.

[0035]

Embedded image

-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 can be manufactured by forming a thin film from these electrode materials by a method such as evaporation or sputtering. The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually 10 n.
The range of m to 1 μm and 50 to 200 nm is preferable. 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. As described above, in the present invention, the electrode used as the cathode may be either a substrate electrode or a counter electrode, depending on the formation position. Transparent body The transparent body sandwiched between the first organic EL element and the second organic EL element is not particularly limited as long as it is optically transparent. For example, a gas such as nitrogen, helium, or argon, Suitable examples include fluorine-based liquids such as perfluoroalkanes, perfluoroamines, and perfluoropolyethers, and adhesives such as epoxy-based and acrylate-based adhesives.

2. Manufacturing Method The manufacturing method of the multicolor light emitting device of the present invention includes (1) a step of forming a first organic EL element, (2) a step of forming a second organic EL element, and (3) superimposing both. Process,
Are roughly divided into

(1) Step of Forming First Organic EL Element The step of manufacturing the first organic EL element is performed, for example, in the following order. Fabrication of Substrate Electrode on Transparent Substrate A film can be formed by an evaporation method, a sputtering method, an EB method, or the like, depending on a material used. The patterning process can be performed using a mask at the time of film formation, or can be performed after the film formation by a photography method or the like. Cleaning of Substrate The substrate is cleaned before forming the organic material. As an example of the cleaning method, a predetermined amount of isopropyl alcohol is put into a quartz container, the substrate is impregnated, and the whole container is put into an ultrasonic cleaner to perform ultrasonic cleaning. Next, ultrasonic cleaning is performed similarly using pure water instead of isopropyl alcohol. Next, ultrasonic cleaning is performed similarly using isopropyl alcohol instead of pure water. The time required for each step is about 5 minutes. Next, after the substrate is dried by spraying a dry inert gas, the substrate is irradiated with ultraviolet rays for about 30 minutes in an ozone atmosphere. Preparation for vapor deposition An organic material is formed by a vacuum vapor deposition method. The washed substrate with the substrate electrode is fixed to a substrate holder of a vacuum evaporation apparatus. Only necessary types of masks for performing patterning are set. The mask is preferably one in which distortion due to heat or the like is unlikely to occur, and examples thereof include a stainless alloy. If the thickness of the mask is significantly larger than the vapor deposition pattern, a uniform pattern cannot be obtained, which is not preferable. An organic substance used for the light emitting layer and the like, and a material used for the counter electrode are set. The organic matter is charged to a molybdenum boat and the boat is fixed to a busbar.
Materials such as metal used for the counter electrode are charged into different boats or filaments depending on the material, and fixed to a bus bar.
The amount charged varies depending on the material. Next, the vacuum chamber is evacuated. When the degree of vacuum reaches about 1 × 10 ⁻⁴ Pa, vapor deposition is started. Preparation of Organic Layer Including Light Emitting Layer A mask for the organic layer is set on the substrate. Next, the boat containing the organic matter is energized to heat the boat. When a predetermined deposition rate is reached, film formation is started, and a film having a predetermined thickness is formed. Organic layers other than the counter electrode are repeatedly formed by the same method, and the organic layers are stacked. The deposition of the film on the substrate is controlled using an openable and closable shutter provided between the substrate and the evaporation source. When there are a plurality of emission colors for one substrate, the mask is changed for each emission color, and the organic layers are stacked in the same manner. Preparation of Counter Electrode After all the organic layers are formed, a counter electrode is formed. Replace with a mask for the counter electrode. The boats containing the material for the counter electrode are heated, and a film is formed at a predetermined vapor deposition rate. When a predetermined film is formed, the film formation is stopped. The vacuum chamber is returned to the atmospheric pressure, and the organic EL element is taken out.

(2) Step of Forming Second Organic EL Element The manufacturing step of the second organic EL element is different from that of the first embodiment only in the number of vapor deposition steps depending on the type of mask, the organic material, the material of the counter electrode, and the number of emission colors. It can be manufactured in the same process as one organic EL element.

(3) Step of superimposing both The method of superimposing the first organic EL element and the second organic EL element is not particularly limited. Anything that can be taken out can be used. For example, a method of sandwiching a transparent body (transparent substance) between the elements, a method of fixing the ends of the elements with an adhesive or the like can be used. It is preferable that the interval between the elements is narrow. However, since the thickness cannot be reduced below the thickness of the element, the thickness is preferably 0.1 μm or more. If the distance is large, the light-emitting area on the back is hidden by the organic EL elements on the front when the organic EL light-emitting device is viewed from an oblique direction, so that the distance is preferably 1 mm or less, more preferably 100 μm or less. Further, when the organic EL elements of the rear panel are reversed, all the organic EL elements can be arranged between the two transparent substrates (FIG. 4D).

Hereinafter, examples of the arrangement of the organic layer including the light emitting layer will be described. Seen from the transparent substrate on the light extraction side,
It is preferable that adjacent light-emitting pixels having light-emitting layers with different emission colors are not arranged on the same substrate. Mask evaporation is one of the methods for easily manufacturing light-emitting pixels having light-emitting layers of different light-emission colors on the same substrate. However, it is usually difficult to reduce the light-emitting area of the light-emitting pixels or narrow the interval. However, in the present invention, the distance between the light-emitting pixels having light-emitting layers of different emission colors on the same substrate is equal to the size of one light-emitting pixel. Pixels can be easily manufactured. As an example of the specific arrangement of the organic material layer including the light emitting layer, for example, in the case of red, green, and blue (R, G, B), as shown in FIG. Divided into three colors and three colors (FIG. 4 (A)), divided into two colors and two colors (FIG. 4 (B)), divided into one color and two colors (FIG. 4 (C),
(D)) and the like. 4D, the distance between R and G or B is reduced by the thickness of the second transparent substrate 201 in FIG. 4C. Thereby, there is an advantage that the viewing angle becomes smaller. In this case, the emission pixel areas of the RGB need not always be equal.

[0042]

EXAMPLES The present invention will be described more specifically with reference to the following examples. Example 1 A substrate electrode line (width 500 μm) made of ITO was formed on a 50 μm thick, 100 mm square glass substrate.
Those formed side by side with an interval of 0 μm were used as transparent substrates. The transparent substrate is subjected to ultrasonic cleaning with isopropyl alcohol for 5 minutes, and then with pure water for 5 minutes.
Finally, ultrasonic cleaning was performed with isopropyl alcohol for 5 minutes. The washed transparent substrate was fixed to a substrate holder of a commercially available vacuum deposition apparatus (manufactured by Nippon Vacuum Engineering Co., Ltd.), and N, N'-diphenyl-N, N'-bis-
(3-methylphenyl)-[1,1′-biphenyl]-
4,4'-diamine (hereinafter referred to as TPD) 200 m
g on another molybdenum resistance heating board.
-Quinolinol) aluminum (hereinafter referred to as Alq)
Into the vacuum chamber and 1 × 10 ^-4 P
The pressure was reduced to a.

Next, the resistance heating board containing the TPD was heated to 215 to 220 ° C., and TPD was deposited on the ITO film at a deposition rate of 0.1 to 0.3 nm / sec. A hole injection layer was formed. At this time, the substrate temperature was room temperature. Next, without removing the transparent substrate on which the hole injection layer was formed from the vacuum chamber, the light emitting layer was formed following the formation of the hole injection layer. The light emitting layer was formed by the above-described resistance heating board containing Alq at 280.
This was performed by heating to a temperature of 0 ° C., depositing Alq on the hole injection layer at a deposition rate of 0.3 nm / sec, and forming an Alq layer having a thickness of 60 nm. The substrate temperature at this time was also room temperature. Next, 1 g of magnesium was put in a molybdenum resistance heating board, 500 mg of silver was put in another molybdenum resistance heating board, and the inside of the vacuum chamber was 2 × 10 ^-4 P
The pressure was reduced to a. Then, the resistance heating board containing magnesium is heated to about 500 ° C. to evaporate magnesium at a deposition rate of about 1.7 to 2.8 nm / sec. The silver was evaporated at a deposition rate of 0.03 to 0.08 nm / sec by heating to about 0 ° C., and a 150 nm-thick counter electrode (cathode) made of a mixed metal of magnesium and silver was applied to a stainless steel mask (thickness). (0.05 mm). A counter electrode having a width of 500 μm and an interval of 540 μm was formed at right angles to the substrate electrode line by using a deposition mask. Thus, a panel of a green light emitting organic EL device was completed. Next, the same transparent substrate as above was washed as above. This transparent substrate was fixed to a substrate holder of a commercially available vacuum deposition apparatus (manufactured by Nippon Vacuum Engineering Co., Ltd.), and N, N ′ was attached to a molybdenum resistance heating board.
-Diphenyl-N, N'-bis (3-methylphenyl)
-(1,1'-biphenyl) -4,4'-diamine (T
PD) and 200 mg of 4,4'-bis (2,2'-diphenylvinyl) on another molybdenum resistance heating board
200 mg of biphenyl (DPVBi) was charged, and the pressure in the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa. Then TP
The board containing D is heated to 215 to 220 ° C, and TPD
Was deposited on the substrate at a deposition rate of 0.1 to 0.3 nm / sec to form a hole injection layer having a thickness of 60 nm. At this time, the substrate temperature was room temperature. Without taking out the obtained hole injection layer from the vacuum chamber, DPVBi was deposited on the substrate at a board temperature of 250 ° C. and a deposition rate of 0.1 to 0.2 nm / sec. A film was formed. At this time, the substrate temperature was room temperature. In addition, tris (8-quinolinol) was added to the molybdenum resistance heating board.
200 mg of aluminum (Alq) was charged, and the pressure in the vacuum chamber was reduced to 2 × 10 ⁻⁴ Pa. The board containing Alq is heated to 280 ° C., and Alq is deposited at a deposition rate of 0.3 n.
An electron injection layer having a thickness of 20 nm was deposited on the substrate at m / sec. After forming the electron injecting layer, the obtained deposit was taken out of the vacuum chamber, a stainless steel mask was placed on the light emitting layer, and was fixed to the substrate holder again.
A counter electrode was prepared in the same manner as described above. As a result, a counter electrode having a width of 500 μm and an interval of 540 μm was formed perpendicular to the substrate electrode line. Thereby, the blue light emitting organic EL
The device panel was completed. The two panels were opposed to each other with the surface having the luminescent pixels and the surface having no luminescent pixels, and the inert liquid (Fluorinert FC-70 manufactured by Sumitomo 3M Limited) was narrowed between them. The two panels were aligned with each other in the length direction of the opposing electrodes, and the opposing electrodes were alternated. As a result, a multicolor light emitting device shown in FIG. 1 in which blue light emission and green light emission were arranged in a plane was obtained. Example 2 The same transparent substrate as used in Example 1 was washed in the same manner and set in the same vacuum evaporation apparatus. At this time, an organic pattern having a width of 240 μm and an interval of 240 μm was formed using a stainless steel mask. Organic materials were produced in the same manner as the green light emitting organic EL device used in Example 1. Next, a stainless steel mask was set so as to fill the gap between the organic substances, and an organic substance having a width of 240 μm and an interval of 240 μm was provided in the same manner as the blue light emitting organic EL element used in Example 1. Further, using another stainless steel mask, a counter electrode having a pattern of 100 μm width and 140 μm interval was produced in the same manner as in Example 1 such that the center thereof overlaps the center of each organic material line. As a result, a panel emitting blue and green light was obtained. Next, Example 1
4-dicyanomethylene-2-methyl-6- (P-dimethylaminostyryl) -4H-pyran was placed in a molybdenum resistance heating board and vapor-deposited simultaneously with Alq of the green light-emitting organic EL device of No. 2, and 2.5 mol% was added. The procedure was the same as in Example 1 except that the cathode was formed into a pattern having a width of 100 μm and an interval of 140 μm using a stainless steel mask. As a result, a panel of a red light emitting organic EL element was obtained. These two panels were bonded together as in Example 1. As a result, an organic EL light emitting device that emits RGB light in a repeating pattern of RGRB shown in FIG. 2 was obtained. If RGRB is one pixel, one pixel is 480
μm × 500 μm. Example 3 Using the organic material used in Example 1, lines of 240 μm in width and 480 μm in interval were formed for each color of blue, green and red using a stainless steel mask. The counter electrode was produced in the same manner as in Example 2. As a result, a panel having an interval of 140 μm for each color could be obtained. Two identical panels were bonded in the same manner as in Example 1. At this time, the green line on the other panel was positioned in the middle between red and blue. As a result, a multicolor light emitting device having an RGB repeating pattern shown in FIG. 3 was obtained. In this case, the interval between each color is 20μ.
m. One pixel of RGB is 360 μm × 500
μm. Comparative Example 1 A panel was prepared in the same manner as in Example 2 except that the organic material pattern used was a stainless steel mask having a width of 120 μm and an interval of 240 μm, and the counter electrode pattern used a stainless steel mask having a width of 100 μm and an interval of 20 μm. Produced. However, the stainless steel mask for the counter electrode is deformed by the heat generated during the preparation of the counter electrode, and the counter electrode is cut off in the middle,
Non-uniform parts occurred.

[0044]

As described above, according to the present invention, a multicolor light emitting device having excellent viewing angle characteristics can be provided. Further, it is possible to provide a method capable of easily and efficiently manufacturing this device.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing one embodiment of a multicolor light emitting device of the present invention.

FIG. 2 is a cross-sectional view schematically showing another embodiment of the multicolor light emitting device of the present invention.

FIG. 3 is a cross-sectional view schematically showing another embodiment of the multicolor light emitting device of the present invention.

FIG. 4 is a cross-sectional view schematically illustrating an example of an arrangement of organic layers including a light emitting layer in the multicolor light emitting device of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 First organic EL element 101 First transparent substrate 102 First substrate electrode 103 Organic layer including first light emitting layer 104 First counter electrode 200 Second organic EL element 201 Second transparent substrate 202 Second substrate electrode 203 Organic layer including second light emitting layer 204 Second counter electrode 300 Transparent body

Claims (3)

[Claims] 1. A first luminescent pixel formed by sequentially laminating a first substrate electrode, an organic material layer including a first luminescent layer, and a first counter electrode is regularly arranged on a first substrate substrate. A plurality of first organic EL elements arranged separately from each other; a second substrate electrode; an organic material layer including a second light emitting layer emitting a color different from the first light emitting layer; and a second counter electrode. A second organic EL element, which is formed by sequentially laminating a plurality of second organic EL elements and a plurality of second organic EL elements arranged regularly and separately from each other on a second substrate, emits light. A multicolor light-emitting device characterized by being superimposed on each other via a transparent body so as not to overlap with each other in a direction. 2. The multicolor light emitting device according to claim 1, wherein at least one of the first light emitting pixel and the second light emitting pixel includes a light emitting layer that emits two or more types of light. 3. A method for manufacturing a multicolor light-emitting device in which a plurality of light-emitting pixels are separately arranged on a substrate, wherein (1)
On a first transparent substrate, a first substrate electrode, an organic layer including a first light emitting layer, and a first counter electrode are sequentially laminated,
Forming a first organic EL element having a plurality of first light-emitting pixels regularly and separated from each other; (2) different from a second substrate electrode and a first light-emitting layer on a second transparent substrate An organic material layer including a second light emitting layer that emits a color, and a second counter electrode are sequentially stacked to form a second organic EL element having a plurality of second light emitting pixels regularly and separated from each other. ,
(3) the first organic EL element and the second organic EL element
A method for manufacturing a multicolor light emitting device, wherein light emitted from each light emitting pixel is not overlapped with each other in a light extraction direction, and is overlapped with a transparent body therebetween.