JPH1012379A - Multicolor light emission device and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multicolor light emission device having superior viewing angle characteristics and a method of simply and efficiently manufacturing this multicolor light emission device. SOLUTION: This device comprises a first organic EL element in which plural light emitting pixels 102, 103, 104, and 105 of red-based color and green- based color are separately arranged respectively laminated on a first substrate 101 and a second organic EL element 200 in which plural light emitting pixels 203, 204, and 205 of blue-based color are arranged laminated on a second substrate 201 so that respective light emitting pixel faces are opposite to each other. Further, the light emitting pixels of red-based color and green-based color are formed from an organic material layer 104 including a single first light emitting layer.

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. In addition, 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 plurality of luminescent pixels of red and green colors are separately arranged on a first substrate. One organic EL element and a second organic EL element formed by arranging a plurality of blue light emitting pixels on a second substrate,
The light-emitting pixels of the red-based color and the green-based color are formed from an organic material layer including a single first light-emitting layer, while the light-emitting pixels are arranged so as to be opposed to each other so that the light-emitting pixel surfaces face each other. A multicolor light emitting device is provided.

In a preferred embodiment, the first light-emitting layer emits yellow-green, yellow, or orange light having a combination of red-colored and green-colored light-emitting regions. A multi-color, wherein a red color filter and a green color filter are disposed between the organic layer including the first light-emitting layer and the first substrate, respectively, corresponding to the green color light-emitting pixels. A light emitting device is provided.

In a preferred embodiment, the first light emitting layer emits green light, and a red conversion medium layer corresponds to the first substrate in correspondence with the red light emitting pixels. A multicolor light-emitting device is provided, which is provided between one substrate electrode.

In a preferred embodiment, the red-based and green-based luminescent pixels are formed from a single organic material layer including the first luminescent layer, and the red-based luminescent pixel is A color filter and / or a color conversion medium layer for converting the color of light emitted from the first light emitting layer to red, and wherein the light emitting pixel of the green system color converts the color of light emitted from the first light emitting layer to green. There is provided a multicolor light emitting device comprising a filter and / or a color conversion medium layer.

In a preferred embodiment, there is provided a multicolor light-emitting device, wherein the first light-emitting layer contains a quinolylate metal complex.

In a preferred embodiment, a multicolor light emitting device is provided, wherein the blue light emitting pixels are formed from an organic layer including a second light emitting layer that emits blue light.

Further, in a method for manufacturing a multicolor light emitting device in which a plurality of light emitting pixels are separately arranged on a substrate,
(1) On a first substrate, a color filter and / or a color conversion medium layer, a first substrate electrode, a green, yellow-green, yellow, or orange color as a part of a red-based or green-based luminescent pixel. An organic material layer including a single first light emitting layer that emits light and a first counter electrode are sequentially laminated to form a first organic EL element. (2) A second substrate electrode is formed on a second substrate. An organic material layer including a second light emitting layer that emits blue light, and a second counter electrode are sequentially laminated to form a second organic EL element,
(3) the first organic EL element and the second organic EL element
A method for manufacturing a multicolor light emitting device is provided, wherein the surfaces on which the first counter electrode and the second counter electrode are formed face each other and overlap each other.

[0011]

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 superimposed roughly.
That is, the first organic EL element 100 is
A red and green color filter and / or color conversion medium layer 102, a first substrate electrode 103, an organic material layer 104 including a single first light emitting layer, and a first counter electrode 105 are formed by sequentially laminating the layers on the first layer 01. Have been. Further, the second organic EL element 200 is formed by sequentially laminating a second substrate electrode 203, an organic material layer 204 including a second light emitting layer, and a second counter electrode 205 on a second substrate 201. . The two elements 100 and 200 are configured to be overlapped such that the respective light emitting pixel surfaces face each other.

Here, the first light emitting layer used in the first organic EL device is of a type (I) that emits yellow or orange light.
And a type (II) that emits green light. According to each type, the light emitting pixels of the red system color and the green system color are arranged in a stripe shape or a mosaic shape. Thus, a two-color light-emitting pixel display device (first organic EL element) can be obtained. In addition, in order to extract light having desired color purity of red system color and green system color, it is preferable to arrange a color filter and a color conversion medium layer shown in Table 1 in combination according to the type of the first light emitting layer.

[0013]

[Table 1]

The second light emitting layer used in the second organic EL element emits blue light. Thus, a blue light emitting pixel display device (second organic EL element) can be obtained. By overlapping the two-color light-emitting pixel display device composed of the first organic EL element and the blue light-emitting pixel display device composed of the second organic EL element, light is extracted from the outside of at least one of the substrates 101 or 201, A multicolor light emitting device capable of multicolor pixel (image) display can be obtained. The first or second substrate electrode may be either an anode or a cathode. The first or second counter electrode may be either an anode or a cathode.

(2) Light-Emitting Pixel and Its Arrangement One light-emitting pixel includes one substrate electrode, one counter electrode,
An organic material layer including a light-emitting layer sandwiched between them, and provided with a color filter and / or a color conversion medium layer as necessary in order to realize a desired color. , Means a place where non-lighting can be controlled. 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, a color filter and a color conversion medium layer are provided in the light extraction direction of the luminescent pixel as necessary. The installation position may be between the substrate and the substrate electrode line, or may be provided above the counter electrode line, but needs to be provided in the light extraction direction. FIG. 1 shows a case where the device is provided between the substrate 101 and the substrate electrode 103.

When such light emitting pixels are observed from the light extraction direction, a multicolor display having various light emitting pixel arrangements such as a stripe arrangement and a 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, in order to increase the color purity of the organic layer 204 including the second light emitting layer that emits blue light in addition to the red and green color filters,
02 is attached. Similarly, in the example illustrated in FIG. 3, the light of the organic material layer 104 including the first light emitting layer is transmitted by the red and green color filters and / or the color conversion medium 202 that are stacked and provided on the second substrate 201. red,
The configuration for emitting green light is shown.

(4) Each component Hereinafter, each component used in the present invention will be specifically described. Substrate The substrate used in the present invention is preferably a rigid material sufficient to support the multicolor light emitting device regardless of transparency.

Specific examples of the material include a glass plate, a ceramic plate, a plastic plate (such as polycarbonate, acrylic, vinyl chloride, polyethylene terephthalate, polyimide, and polyester resin), and a plate made of the same material as the insulating layer described later. Can be mentioned. The thickness of the substrate is not particularly limited. Usually 100 μm
２2 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,
A dielectric transparent material such as SnO ₂ or ZnO is 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, it is selected in the range of 10 nm to 1 μm, preferably 10 to 200 nm. As described above, in the present invention, the electrode used as the anode may be either a substrate electrode or a counter electrode, depending on the formation position.

-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)

[0024]

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

In the above formula, Y ^{1 to} Y ⁴ each represent a hydrogen molecule, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aralkyl group having 7 to 8 carbon atoms, a substituted or unsubstituted An 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, and an alkoxy group having 1 to 6 carbon atoms are shown. Here, the substituent is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aralkyl group having 7 to 8 carbon atoms, an aryloxy group having 6 to 18 carbon atoms, an acyl having 1 to 6 carbon atoms. Group, acyloxy group having 1 to 6 carbon atoms, carboxyl group, styryl group, arylcarbonyl group having 6 to 20 carbon atoms, aryloxycarbonyl group having 6 to 20 carbon atoms, alkoxycarbonyl group having 1 to 6 carbon atoms, vinyl group , Anilinocarbonyl group, carbamoyl group, phenyl group, nitro group, hydroxyl group or halogen. These substituents may be single or plural. Y ^{1 to} Y ⁴ may be the same or different from each other;
Y ¹ and Y ² and Y ³ and Y ⁴ may combine with each other to form a substituted or unsubstituted saturated 5-membered ring or a substituted or unsubstituted saturated 6-membered ring. Ar represents a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, which may be monosubstituted or plurally substituted, and the bonding portion may be any of ortho, para and meta. However, when Ar is an unsubstituted phenylene group, Y ^{1 to} Y ⁴
Is an alkoxy group having 1 to 6 carbon atoms, and 7 to 8 carbon atoms.
Selected from an aralkyl group, a substituted or unsubstituted naphthyl group, a biphenyl group, a cyclohexyl group and an aryloxy group. Examples of such a distilylylene-based compound include the following.

[0027]

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[0028]

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As another preferable 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.

[0030]

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(Wherein, Mt represents a metal, and n represents 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 (hereinafter abbreviated as Alq), 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 (5,5
7-dipromo-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 preferred 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 (II
I), bis (2-methyl-8-quinolinolate) (2,
3-dimethylphenolato) aluminum (III), bis (2-methyl-8-quinolinolate) (2,6 dimethylphenolate) aluminum (III), bis (2-methyl-8-quinolinolate) (3,4-dimethyl Phenolate) aluminum (III), bis (2-methyl-8)
-Quinolinolate) (3,5-dimethylphenolate)
Aluminum (III), bis (2-methyl-8-quinolinolate) (3,5-di-t-butylphenolate) aluminum (III), bis (2-methyl-8-quinolinolate) (2,6-diphenylphenol Latet) aluminum (III), bis (2-methyl-8-quinolinolate) (2,4,6-triphenylphenolato) aluminum (III), and the like. These luminescent materials may be used alone or in combination of two or more.

The following is a more specific description. 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.

The method for forming the light emitting layer in the device used in the present invention includes, for example, an evaporation 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 resulting therefrom. 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 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.

Representative examples of the porphyrin compounds 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 abbreviated as TPD), 4,4′-
Bis [N, N-di- (3-tolyl) amino] -4 "-phenyl-triphenylamine (hereinafter abbreviated as TPD74), 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. 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) and triphenylamine unit described in JP-A-4-308688,
And 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (hereinafter abbreviated as MTDATA) and the like in a starburst type. Further, in addition to the above-mentioned aromatic dimethylidin compound shown as a material for the light emitting layer, p
Inorganic compounds such as -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. 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. 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.

-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)

[0042]

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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.

[0044]

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-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.

Color Filter The color filter used in the present invention is not particularly limited as long as it has a function of extracting red or green light emission from yellow or orange incident light. For example, a color filter in which a pigment is dispersed in a transparent resin is used. Can be mentioned. Here, examples of the transparent resin include polymethyl methacrylate, polycarbonate, polyvinyl alcohol, and polyacrylate. The pigment used for extracting green light emission is a green pigment, preferably a phthalocyanine-based or halogenated phthalocyanine, and the red pigment is preferably a perylene pigment. In order to separate and arrange the color filters in a plane, it is preferable to perform photolithography using a transparent resin such as an acrylic acid-based, methacrylic acid-based, or polyvinyl cinnamate-based resist material.

Color conversion medium layer The color conversion medium used in the present invention is one in which a fluorescent dye is dispersed in a transparent medium, and in the present invention, means a substance having a function of changing green incident light to red. For a fluorescent dye that converts the light emission of such a green light emitting element from orange to red light, for example, 4-dicyanomethylene-
2-methyl-6- (p-dimethylaminostillin)-
A cyanine dye such as 4H-pyran (hereinafter DCM);
Ethyl-2- (4- (p-dimethylaminophenyl)-
Examples thereof include pyridine dyes such as (1,3-butadienyl) -pyridium-percolarate (hereinafter referred to as pyridine 1), xanthine dyes such as rhodamine B and rhodamine 6G, and oxazine dyes. Further, various dyes (direct dyes, acid dyes, basic dyes, disperse dyes, etc.) can be used as long as they have fluorescence. Alternatively, the fluorescent dye may be kneaded in a resin in advance to form a pigment.

These fluorescent dyes may be used alone or as a mixture, if necessary. In particular, since the conversion efficiency of fluorescence into red light is low, the conversion efficiency from light emission to fluorescence can be increased by using a mixture of the above dyes. On the other hand, resin
A transparent (50% or more visible light) material is preferred. For example, transparent resins (polymers) such as polymethyl methacrylate, polyacrylate, polycarbonate, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyethyl cellulose, carboxymethyl cellulose and the like can be mentioned. Note that a transparent photosensitive resin to which a photolithography method can be applied in order to separate and arrange the phosphor layers in a plane can also be selected. For example, a photocurable resist material having a reactive vinyl group such as an acrylic acid type, a methacrylic acid type, a polyvinyl cinnamate type, and a ring rubber type may be used. When a printing method is used, a printing ink (medium) using a transparent resin can be selected. For example, monomers, oligomers and polymers of melamine resin, phenol resin, alkyd resin, epoxy resin, polyurethane resin, polyester resin, maleic acid resin, polyamide resin, polymethyl methacrylate, polyacrylate, polycarbonate, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxy Transparent resins such as ethyl cellulose and carboxymethyl cellulose can be used.

When the phosphor layer is mainly composed of a fluorescent dye,
A film is formed by a vacuum evaporation or sputtering method through a mask of a desired phosphor layer pattern. On the other hand, when the film is formed of a fluorescent dye and a resin, the fluorescent dye and the above resin and resist are mixed, separated or solubilized, and spin-coated. , Roll coating, film formation by a method such as a casting method, and patterning with a desired phosphor layer pattern by a photolithography method,
In general, patterning is performed with a desired phosphor layer pattern by a method such as screen printing. The film thickness of the phosphor layer made of a fluorescent dye or a fluorescent dye and a resin is not limited as long as it does not interfere with the function of generating the fluorescence by sufficiently absorbing the light emitted from the organic EL element. Although different, about 10 nm to 1 mm is appropriate.
In particular, those in which the phosphor layer is made of a fluorescent dye and a resin,
It is sufficient that the concentration of the fluorescent dye is within a range that does not cause quenching of the concentration of the fluorescence and that the emission of the organic EL element can be sufficiently absorbed. Depending on the type of the fluorescent dye, a concentration of 1 to 10 ^-4 mol / kg is suitably used for the resin used.

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 forming the first organic EL element can include, for example, the following steps: Substrate cleaning process Color filter film formation or color conversion medium layer film formation process Color filter or color conversion medium patterning process Flattening layer film formation process Transparent electrode film formation process and patterning process Organic layer film formation process Cathode metal film formation and patterning process Is not particularly limited, and for example, ultrasonic cleaning with isopropyl alcohol can be mentioned. Regarding and, when a color filter is used, a color resist is used to form a red color resist for a red pixel, and after exposure through a photomask, a color resist pattern is left with a predetermined pattern. A green color resist for a green pixel is formed, and the color resist film is similarly left in a predetermined pattern. When the medium itself has photosensitivity as a color conversion medium, a red conversion medium pattern can be formed in the same manner as in the case of a color filter. As another method, after forming a color conversion medium, a photoresist is formed thereon, and after exposure through a photomask, a photoresist pattern is left. Further, a method in which a portion where no photoresist remains is etched with various solvents (for example, a dilute hydrochloric acid aqueous solution or 10 to 20% acetic acid), and the photoresist is further stripped to form a red conversion medium pattern film. it can.
With respect to the above, it is preferable to form various transparent resins in order to flatten the unevenness due to the color filter or the color conversion medium. The transparent resin (for example, polyurethane or acrylic resin) used for this is formed into a film by a spin coating method, cured by heat, and dried and cured. As for the transparent electrode and the cathode, a film can be formed by a known sputtering or vapor deposition method, and the transparent electrode can be patterned by a photoline graph method. Regarding the above, the organic layer is preferably formed into a multilayer film by vacuum evaporation. As for the patterning of the cathode, cathode deposition using a shadow mask can be used.

(2) Step of Forming Second Organic EL Element The step of forming the second organic EL element can be, for example, the following steps: Substrate cleaning step Transparent electrode film forming step Organic layer film forming step Cathode metal film forming and patterning steps are the same as in the case of forming the first organic EL element. As for the transparent electrode, the transparent electrode can be formed by a known sputtering or vapor deposition method, and further, can be patterned by a photolinography method. As for the organic layer, a multilayer film can be formed by vacuum evaporation. As for the deposition and patterning of the cathode metal,
Cathode vapor deposition using a shadow mask can be used.

(3) Step of superposing both The step of superposing the two is performed, for example, after positioning.
The first and second organic EL elements can be bonded together with the element forming sides of the first and second organic EL elements facing each other using a thermosetting or photocurable adhesive. At this time, it is preferable to provide a gap so that the first organic EL element and the second organic EL element do not contact each other.

[0054]

EXAMPLES The present invention will be described more specifically with reference to the following examples. [Embodiment 1] This embodiment is an example in which a color filter and an orange light emitting layer are combined and used as red light emitting pixels and green light emitting pixels. Preparation of color filter 110 μm × 280 μm red color filter and 1
A color filter in which green color filters of 10 μm × 280 μm were alternately arranged in a stripe shape was manufactured. The arranged number is (360 × 240)
Was individual. The fabrication method was as follows. 1.1mm
A photosensitive color resist manufactured by Fuji Hunt Co. was spin-coated on a 10 cm square glass substrate, exposed through a photomask, and developed. First, a green color filter was produced using a green color resist, and a red color filter was produced using a red color resist. Next, a polyurethane-based coating agent (manufactured by Hodogaya Chemical Co., Ltd.) was spin-coated on the entire surface of the color filter as a protective film for the color filter, and baked at 80 ° C.

Production of ITO Stripe Next, ITO was formed on the entire surface of the substrate by sputtering so as to have a thickness of 200 nm. The sheet resistance was 30Ω / □. Next, ITO was striped by photolithography. The stripe pitch was 120 μm and the ITO width was 110 μm, and the pattern processing was performed so as to overlap the already provided color filters (FIG. 4).

Production of First Organic EL Element (Red Component,
The color filter obtained in (2) capable of emitting a green component was ultrasonically washed with isopropyl alcohol for 5 minutes. Next, UV ozone cleaning was performed for 30 minutes. This substrate was mounted on a substrate holder of a vacuum evaporation apparatus. Next, MTDA was used as a hole injection layer.
TA was deposited to a thickness of 80 nm. Further, NP as a hole transport layer
D was deposited to a thickness of 20 nm. Further, Alq was deposited as a host material of the light emitting layer, coumarin 6 was used as a green fluorescent dye, and DCM was deposited as a red fluorescent dye at a deposition rate ratio of 30: 0.5: 0.6 to a thickness of 60 nm. Finally, put a deposition mask on the Mg:
An Ag alloy was deposited to a thickness of 200 nm. The deposition rate ratio between Mg and Ag was 14: 1. The opening of the evaporation mask is 230μ.
m width stripes, Mg: A at 300 μm pitch
g The cathode stripe can be formed so as to intersect perpendicularly with ITO. As a result, an organic ELXY matrix element capable of simultaneously emitting red-based light from DCM and emitting green-based light from Coumarin 6 was obtained. A driving test of this device confirmed that both the red light emitting pixel and the green light emitting pixel emit light, and that two-color image display can be performed. The emission color of the element without using the color filter was orange.

Preparation of Second Organic EL Element A glass plate on which 360 ITO stripes having a pitch of 360 μm and a width of 110 μm were arranged was prepared. Next, this was washed in the same manner as described above, and attached to a substrate holder of a vacuum evaporation apparatus. Next, MTDATA, NPD, DPVB as a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer.
i and Alq were deposited to a film thickness of 80, 20, 60, 2 respectively.
Deposited at 0 nm. Next, a Mg: Ag alloy is coated to a thickness of 20 nm.
Was deposited. This Mg: Ag alloy cathode was thin and light-transmissive.

[0058] a first element having a red produced in both overlay above, the green light emitting pixel, and a second element manufactured in said laminated with an ultraviolet-curing resin. The cross section is shown in FIG. Lamination was performed in a glove box filled with dry nitrogen. Next, a driving circuit was connected to this element, and an image was displayed. It was confirmed that multicolor (green, blue, red) image display could be performed. The observation of this image was performed from the outer surface of the first substrate.

[Embodiment 2] This embodiment is an example in which a color conversion medium is used as a red light emitting pixel, and this is used in combination with a green light emitting layer. A red conversion medium having a pattern processing width of 110 μm and a red conversion medium arranged in stripes was prepared on a glass substrate. The lateral pitch was 360 μm. As a red conversion medium, poly (4-vinylpyridine) as a polymer and rhodamine 6 are used.
G, rhodamine B, and DCM dispersed as a red fluorescent dye were used. Rhodamine 6G, Rhodamine B 0.03 mol, DCM 0.03 mol per kg of polymer
To be moles. The red conversion medium was formed by dissolving 3 g of the material having the above-described concentration ratio in 10 g of ethyl cellosolve and spin coating the solution. Further, a positive type photoresist is formed on this film, irradiated with an ultraviolet ray of 100 mJ / cm ² , and after development, a red fluorescent medium is further added with 1% by weight of H.
Etching was performed with a Cl aqueous solution. Further, the positive resist was removed. Further, a polyurethane-based coating agent was spin-coated on the red conversion medium and baked at 80 ° C.

Preparation of ITO Stripe ITO was sputtered on the red color conversion medium in the same manner as in Example 1, and further striped. FIG. 6 shows the pattern.

Production of First Organic EL Device Next, a green light-emitting device was produced in the same manner as in Example 1. However, DCM as a red fluorescent dye was not deposited. When a driving test was performed on this element, it was confirmed that a red light-emitting pixel having a red conversion medium was displayed in red, and a portion having no red light-emitting pixel was displayed in green.

Superposition (lamination) The element obtained in Example 1 and the element obtained in Example 1 were laminated. Lamination was performed using a UV-curable resin in a glove box under dry nitrogen. Next, when a driving test of this element was performed, red, green,
It was confirmed that multicolor display of blue can be performed.

[0063]

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 view showing an embodiment of a multicolor light emitting device according to the present invention;
It is sectional drawing which shows the pattern of a TO stripe typically.

FIG. 5 is a cross-sectional view schematically showing one embodiment of the multicolor light emitting device of the present invention.

FIG. 6 shows a multicolor light emitting device according to another embodiment of the present invention.
It is sectional drawing which shows the pattern of a TO stripe typically.

[Explanation of symbols]

 100: first organic EL element 101: first substrate 102: color filter and / or color conversion medium layer 103: first substrate electrode 104: organic material layer including first light emitting layer 105: first counter electrode 200: first Second organic EL element 201: second substrate 202: color filter and / or color conversion medium layer 203: second substrate electrode 204: organic material layer including second light emitting layer 205: second counter electrode

Claims (7)

[Claims] 1. A first organic EL element in which a plurality of luminescent pixels of red system color and green system color are separately arranged on a first substrate, and a blue system device on a second substrate. A second organic EL element in which a plurality of light-emitting pixels of the same color are arranged is disposed so as to overlap with each other so that the respective light-emitting pixel surfaces face each other. A multicolor light emitting device, wherein the light emitting pixels are formed from an organic layer including a single first light emitting layer. 2. The first light-emitting layer emits yellow-green, yellow, or orange light having a red light-emitting color and a green light-emitting region, and emits the red light and the green light. 2. The multi-color filter according to claim 1, wherein a red color filter and a green color filter are disposed between the organic layer including the first light emitting layer and the first substrate, respectively, corresponding to the pixels. Light emitting device. 3. The first light-emitting layer emits green light, and corresponds to the red-based light-emitting pixels.
The multicolor light emitting device according to claim 1, wherein the red conversion medium layer is provided between the first substrate and the first substrate electrode. 4. The red-based and green-based luminescent pixels are formed from a single organic material layer including the first luminescent layer, and the red-based luminescent pixel is a first luminescent layer. A color filter and / or a color conversion medium layer for converting a light emission color from the first light emitting layer to red, and a color filter and / or a color for converting the light emission color from the first light emitting layer to green. The multicolor light emitting device according to claim 1, further comprising a conversion medium layer. 5. The method according to claim 1, wherein the first light-emitting layer contains a quinolylate metal complex.
The multicolor light-emitting device according to any one of the preceding claims. 6. The multicolor light emitting device according to claim 1, wherein said blue light emitting pixel is formed of an organic material layer including a second light emitting layer which emits blue light. Light emitting device. 7. 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)
A color filter and / or a color conversion medium layer, a first substrate electrode, and emits green, yellow-green, yellow, or orange light as a part of red-based and green-based light-emitting pixels on a first substrate. An organic layer including a single first light-emitting layer and a first counter electrode are sequentially laminated to form a first organic EL element. (2) On a second substrate, a second substrate electrode, a blue An organic material layer including a second light emitting layer that emits light and a second counter electrode are sequentially laminated to form a second organic EL element, and (3)
A method for manufacturing a multicolor light emitting device, comprising: superposing a first organic EL element and a second organic EL element with their surfaces on which a first counter electrode and a second counter electrode are formed facing each other. .