JP2001196175A - Organic el display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an organic EL display device which enables to compensate the light of colors not included or insufficient in the light emitted from a luminous layer, and enables to prevent a color filter from disconnection of wiring caused by the difference in level created on the color filter as well, with high quality and good yield at low cost. SOLUTION: The organic EL display device has a color filter layer, a fluorescence conversion layer, a barrier layer, a hole injection layer and an electron injection layer in this or in the reversed sequence to the above sequence on a substrate, and an organic layer related to the luminescence function between the above electrodes. The fluorescence conversion layer and the color filter layer are formed by vapor deposition method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic EL (electroluminescence) device, and more particularly, to a filter structure of an organic EL display device used for an element which emits light by applying an electric field to a thin film of an organic compound.

[0002]

2. Description of the Related Art In recent years, organic EL devices have been actively studied. In this method, a hole transport material such as triphenyldiamine is formed on a hole injection electrode such as tin-doped indium oxide (ITO), and a fluorescent substance such as an aluminum quinolinol complex (Alq3) is laminated as a light emitting layer. the element having a basic structure forming a small metal electrode (electron injecting electrode) work function such as mg, is noted by a very high luminance of several 100 to several 10,000cd / m ² at 10V before and after the voltage obtained ing.

[0003] By the way, as a display using such an organic EL element, various application examples are considered.
In particular, application to a color display is an important issue. When applying the luminous body as a color display,
For example, (1) A light emitting layer of each color of red, green, and blue is formed for each pixel. (2) The light-emitting layer emits white light, and a ternary color of blue, green and red is obtained using a color filter layer. (3) The light-emitting layer emits monochromatic light such as blue light, and obtains other display colors by combining a fluorescence conversion layer made of a fluorescent material or a color filter layer with this. Such a method is common.

However, when a plurality of luminescent colors are prepared by the luminous body itself, there are few suitable fluorescent materials for the luminescent layer for emitting red light, and there is a problem that it is difficult to obtain red with high color purity. In addition, the lifetime of the blue light emitting layer is extremely shorter than that of the other light emitting layers, so that the lifetime of the entire light emitting device is governed by the lifetime of the blue light emitting layer.

On the other hand, the method of forming a color display by combining a single light emitting layer and a fluorescence conversion layer and / or a color filter layer made of a fluorescent material can be constituted only by a single organic EL element. However, it can be said that this method is excellent not only in that it is simple and inexpensive, but also in that full color can be obtained by patterning the fluorescence conversion layer and / or the color filter layer. However, it is extremely difficult to provide a fluorescence conversion layer and / or a color filter layer in a predetermined pattern on the organic EL structure by a photoresist technique in terms of a patterning technique, damage to the organic EL structure, and the like. In addition, a fluorescent conversion layer and / or a color filter layer are formed on the substrate by patterning,
When the organic EL structure is laminated thereon, a step is formed, which causes a break (discontinuous portion of the film), and the wiring cannot be connected, so that no current flows and the organic EL element does not function as an organic EL element. There was a problem that would.

In addition, the color resist material used for forming the color filter layer is a very expensive material. If the color filter layer can be formed without using such a material, a product using an organic EL element is used. Can be provided at extremely low cost.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to make it possible to compensate for light of a color that is not included in the light emitted from the light-emitting layer or light of an insufficient color, and to achieve a high-quality and low-cost yield. It is an object of the present invention to provide an organic EL display device which is capable of preventing disconnection of a wiring due to a step of a color filter.

[0008]

Means for Solving the Problems That is, the above object is as follows.
This is achieved by the following configuration. (1) A color filter layer, a fluorescence conversion layer, a barrier layer, a hole injection electrode and an electron injection electrode are sequentially provided on a substrate, and an organic layer involved in a light emitting function is provided between these electrodes. An organic EL display device in which the color filter layer is formed by an evaporation method. (2) The organic EL display device according to (1), wherein the color filter layer is formed of a pigment. (3) The thickness of the color filter layer is 2000 nm.
The following organic EL display device of (1): (4) The vapor deposition method is a mask vapor deposition method (1).
The organic EL display device according to any one of (1) to (3). (5) The emission light obtained from the emission layer is a monochromatic emission having an emission wavelength bandwidth of 430 to 530 nm or less.
The organic EL display device according to any one of (4). (6) an electron injection electrode, a hole injection electrode,
A fluorescent conversion layer and a color filter layer are sequentially provided, and an organic layer involved in a light emitting function is provided between the electrodes. The color filter layer is formed of an organic layer formed by an evaporation method.
L display device. (7) The organic EL display device according to (6), wherein the color filter layer is formed of a pigment. (8) The thickness of the color filter layer is 2000 nm.
The following organic EL display device of (6) or (7). (9) The vapor deposition method is a mask vapor deposition method (6).
The organic EL display device according to any one of (1) to (8). (10) The emission light obtained from the emission layer is a monochromatic emission having an emission wavelength bandwidth of 430 to 530 nm or less.
The organic EL display device according to any one of (1) to (9). (11) The above (6) to (1) having a resin sealing structure
0) The organic EL display device according to any one of the above.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The organic EL display device of the present invention has a color filter layer, a fluorescence conversion layer, a barrier layer, a hole injection electrode and an electron injection electrode on a substrate in order. The organic light-emitting device further includes an organic layer involved in a light-emitting function, and the fluorescence conversion layer and the color filter layer are formed by an evaporation method. Alternatively, an electron injection electrode, a hole injection electrode, a fluorescence conversion layer, a color filter layer, and a barrier layer are sequentially provided on a substrate having a stack opposite to the above, and a light emitting function is involved between the electrodes. Having an organic layer, the fluorescence conversion layer,
The color filter layer is formed by a vapor deposition method.

As described above, the color filter layer is formed by the vapor deposition method, and the fluorescent conversion layer is formed on the color filter layer by the vapor deposition method. Can compensate for the light of the different colors. Also,
The color filter layer and the fluorescence conversion layer can be formed continuously.

Further, the thicknesses of the color filter layer and the fluorescence conversion layer can be made extremely thin, and problems such as disconnection of wiring at the step can be prevented. Also, since the filter layer can be formed without using an expensive resist material, the organic E
Since the cost of the L display device can be reduced, and a component other than the pigment is not contained, a filter having high color purity can be formed. Further, since the color filter layer is formed of a flat thin film, an overcoat layer is not required, the number of manufacturing steps is reduced, the number of manufacturing steps can be reduced, and the cost can be further reduced. Further, by using the mask vapor deposition method, the three primary colors can be separated very easily, and a filter for full-color display can be arranged even in a small pixel area.

The fluorescent conversion layer converts light emitted from the light emitting layer into light of a predetermined color. Specifically, it has a fluorescent substance which is excited by light incident from the light emitting layer and emits light having a wavelength different from the incident light. Fluorescent substances emit light of a wavelength different from the incident light determined by their energy order, and there are compounds that emit fluorescent light such as blue, green, yellow, and red, but are used for organic EL devices. In this case, a compound that emits each fluorescence such as green, yellow, and red is preferable. Since the fluorescent substance converts short-wavelength light into long-wavelength light, an arbitrary color can be easily obtained by converting blue light emission into green, yellow, red, or other colors.

As such a fluorescent substance, for example,
Examples include compounds as disclosed in JP-A-63-264692, for example, at least one selected from compounds such as quinacridone, rubrene, styryl dyes, and compounds such as coumarin and luminogen. Also, Tris (8
Quinolinol derivatives such as metal complex dyes having 8-quinolinol or a derivative thereof as a ligand, such as (quinolinolato) aluminum; tetraphenylbutadiene, anthracene, perylene, coronene, and 12-phthaloperinone derivatives. Further, phenylanthracene derivatives described in JP-A-8-12600 (Japanese Patent Application No. 6-110569), tetraarylethene derivatives described in JP-A-8-12969 (Japanese Patent Application No. 6-114456), and the like are described. Can be used.

The thickness of the fluorescence conversion layer is preferably 2000
nm or less, particularly about 300 to 600 nm. The thickness of the color filter layer is preferably 2,000 nm or less, particularly 3 nm.
It is about 00 to 600 nm. If the thickness of the fluorescence conversion layer and the color filter layer is too small, the function as the fluorescence conversion layer and the color filter layer is reduced. On the other hand, if the film thickness is too large, the film-forming step takes too much time, and the thickness of the entire device becomes too large, which tends to cause problems such as disconnection.

The color filter layer may be appropriately selected from those that can be formed by a vapor deposition method, and may be used appropriately. The characteristics of the color filter are adjusted according to the light emitted from the organic EL element, and the extraction efficiency is adjusted. -Color purity may be optimized. Specifically, organic pigments are preferred, and among them, polycyclic pigments or azo pigments are preferred.

The polycyclic pigments include phthalocyanine-based pigments,
Anthraquinone-based, perylene and perinone-based, thioindigo-based, quinacridone-based, dioxazine-based, isoindolinone-based, quinophthalone-based and the like, among these, quinacridone-based as a red-based filter, phthalocyanine-based as a blue-based filter, As the green filter, a mixture of the quinacridone type and the phthalocyanine type is preferable.

As the azo pigments, insoluble azo pigments are preferable, and monoazo pigments such as β-naphthol type, naphthol AS type, acetoacetate arylamide type, and disazo pigments such as acetoacetate arylamide type, pyrazolone type are preferable.

Further, when an EL element material or a material capable of cutting off short-wavelength external light that is absorbed by the fluorescence conversion layer is used in combination, the light resistance of the element and the display contrast are improved.

For forming the fluorescence conversion layer and the color filter layer, an evaporation method is used, and a mask evaporation method is particularly preferable. When the vapor deposition method is used, the fluorescent substance and the color filter material are directly vaporized to form a film.

The conditions for vacuum deposition are not particularly limited.
The degree of vacuum is 0 ^-4 Pa or less, and the deposition rate is 0.01 to 1 nm.
/ Sec.

In the case where a plurality of compounds are contained in a case where a vacuum conversion method is used for forming the fluorescent conversion layer and the color filter layer, it is preferable to co-deposit each boat containing the compounds by individually controlling the temperature.

When the fluorescent conversion layer and the color filter layer serve as an underlayer, that is, when formed between the substrate and the organic EL structure, a barrier layer is provided between the fluorescent conversion layer and the color filter layer and the electrode. Is preferably formed. By forming the barrier layer, the fluorescence conversion layer and the color filter layer can be protected from etching, cleaning solution, and the like when patterning the electrode. In the case of a so-called reverse lamination structure, it is preferable to form a barrier layer so as to cover the fluorescence conversion layer and the color filter layer formed on the hole injection electrode. In this case, the barrier layer prevents moisture and gas, and prevents the organic EL structure from being corroded and contaminated. Alternatively, it may be formed between the electrode and the color filter layer as necessary, or may be omitted.

The barrier layer is preferably formed of silicon oxide and preferably has a refractive index at 632 nm of 1.4.
0 to 1.55, more preferably 1.44 to 1.48. If the refractive index is higher than this, barrier properties against components in the organic layer will be lost. If it is low, barrier properties against moisture and the like will be lost.

The barrier layer, in addition to SiO _x, it may be a SiN _y, as further unavoidable impurities, C, and Ar and the like may also contain the following 0.5 wt%. Further, H may be contained in an amount of 30 at% or less in order to reduce the stress in the film.

The _x of SiO _x is 1.8 to 2.2, especially 1.
It is preferably from 90 to 2.05. _Y of SiN _y is preferably 0.1 to 0.5. If x and y are such values as an average value of the entire barrier layer, the values of x and y may have a gradient in the thickness direction.

The average surface roughness (Ra) of the barrier layer surface is as follows:
2-50 nm is preferred. Also, the maximum surface roughness (Rmax)
Is preferably 10 to 50 nm. If the flatness of the film on the surface of the barrier layer deteriorates, current leakage and dark spots may occur. Therefore, it is preferable that appropriate film forming conditions are selected, abnormal grain growth is suppressed, and the average surface roughness (Ra) and the maximum surface roughness (Rmax) of the interface in contact with the hole injection electrode are within the above ranges.

The light transmittance of the barrier layer is 80%.
It is preferable that it is above. When the transmittance is low, the light emission from the light emitting layer itself is attenuated, and the luminance required for the light emitting element tends not to be obtained.

The thickness of the barrier layer is not particularly limited as long as it is within the above range, but is 5 to 50 nm, especially 10 to 3 nm.
Preferably, it is 0 nm.

The film containing SiO _x is formed by plasma C
Although a film can be formed by a VD method or the like, the film is preferably formed by a sputtering method. In order to form a film as described above, a high-frequency sputtering method using an RF power source is particularly preferable. In the plasma CVD method, there is a high possibility that hydrogen is mixed into a film due to a reaction gas, which may deteriorate the barrier property against moisture.

When a film is formed by a sputtering method, an inert gas used in a usual sputtering apparatus can be used as a sputtering gas. Among them, it is preferable to use any of Ar, Kr, and Xe, or a mixed gas containing at least one of these gases.

When any of Ar, Kr, and Xe is used as the main sputtering gas, the product of the distance between the substrate targets is 20 to 60 Pa · cm, particularly 30 to 50 Pa · cm.
Is preferable. Under these conditions, a preferable result can be obtained by using any sputtering gas, but it is particularly preferable to use Ar.

As the sputtering method, it is preferable to use the RF sputtering method. The power of the RF sputtering device is 10
A range of 100 W / cm ² is preferred. The frequency is 13.56
MHz is preferred. The deposition rate is preferably in the range of 5 to 50 nm / min. The pressure during film formation is preferably in the range of 0.1 to 1 Pa.

Next, the organic layer provided in the organic EL device of the present invention will be described. The organic layer includes a light emitting layer. The light emitting layer is composed of a laminated film of at least one kind or two or more kinds of organic compound thin films involved in the light emitting function.

The light emitting layer has a function of injecting holes (holes) and electrons, a function of transporting them, and a function of generating excitons by recombination of holes and electrons. By using a relatively electronically neutral compound for the light emitting layer, electrons and holes can be easily injected and transported in a well-balanced manner.

The light-emitting layer may have a hole injection / transport layer, an electron injection / transport layer, etc. in addition to the light-emitting layer in a narrow sense, if necessary.

The hole injecting and transporting layer has a function of facilitating the injection of holes from the hole injecting electrode, a function of stably transporting holes, and a function of preventing electrons.
The electron injection transport layer has a function of facilitating injection of electrons from the electron injection electrode, a function of stably transporting electrons, and a function of preventing holes. These layers increase and confine holes and electrons injected into the light emitting layer, optimize the recombination region, and improve luminous efficiency.

The thickness of the light emitting layer, the thickness of the hole injecting and transporting layer, and the thickness of the electron injecting and transporting layer are not particularly limited, and vary depending on the forming method.
It is preferable that the thickness be in the range of 10 to 300 nm.

The thickness of the hole injecting and transporting layer and the thickness of the electron injecting and transporting layer depend on the design of the recombination / light emitting region, but may be about the same as the thickness of the light emitting layer or about 1/10 to 10 times. When the hole / electron injection layer and the transport layer are separated, the thickness of the injection layer is preferably 1 nm or more, and the thickness of the transport layer is preferably 1 nm or more. At this time, the upper limit of the thickness of the injection layer and the transport layer is usually about 500 nm for the injection layer and about 500 nm for the transport layer. Such a film thickness is the same when two injection / transport layers are provided.

The light emitting layer of the organic EL element contains a fluorescent substance which is a compound having a light emitting function. Examples of such a fluorescent substance include, for example, JP-A-63-26469.
No. 2 discloses at least one compound selected from compounds such as quinacridone, rubrene, and styryl dyes. Also, Tris (8
Quinolinol derivatives such as metal complex dyes having 8-quinolinol or a derivative thereof as a ligand, such as (quinolinolato) aluminum; tetraphenylbutadiene, anthracene, perylene, coronene, and 12-phthaloperinone derivatives. Further, phenylanthracene derivatives described in JP-A-8-12600, JP-A-8-1600
For example, a tetraarylethene derivative described in JP-A-2969 can be used.

Further, it is preferable to use in combination with a host substance capable of emitting light by itself, and it is also preferable to use it as a dopant. In such a case, the content of the compound in the light emitting layer is preferably 0.01 to 10% by volume, more preferably 0.1 to 5% by volume. Particularly, in the case of a rubrene-based material, the content is preferably 0.01 to 20% by volume. When used in combination with a host substance, the emission wavelength characteristics of the host substance can be changed, light emission shifted to a longer wavelength becomes possible, and the luminous efficiency and stability of the device are improved.

The host substance is preferably a quinolinolato complex, and more preferably an aluminum complex having 8-quinolinol or a derivative thereof as a ligand. Such an aluminum complex is disclosed in JP-A-63-26469.
No. 2, JP-A-3-255190, JP-A-5-7707
3, JP-A-5-258859, JP-A-6-2158
No. 74 and the like.

Specifically, first, tris (8-quinolinolato) aluminum, bis (8-quinolinolato) magnesium, bis (benzo {f} -8-quinolinolato) zinc, bis (2-methyl-8-quinolinolato) aluminum Oxide, tris (8-quinolinolato) indium,
Tris (5-methyl-8-quinolinolato) aluminum, 8-quinolinolatolithium, tris (5-chloro-
8-quinolinolato) gallium, bis (5-chloro-8-
Quinolinolato) calcium, 5,7-dichloro-8-quinolinolatoaluminum, tris (5,7-dibromo-
8-hydroxyquinolinolato) aluminum and poly [zinc (II) -bis (8-hydroxy-5-quinolinyl) methane].

An aluminum complex having another ligand in addition to 8-quinolinol or a derivative thereof may be used.
8-quinolinolato) (phenolato) aluminum (III)
, Bis (2-methyl-8-quinolinolato) (ortho-
Cresolato) aluminum (III), bis (2-methyl-
8-quinolinolato) (meth-cresolate) aluminum
(III), bis (2-methyl-8-quinolinolato) (para-cresolato) aluminum (III), bis (2-methyl-8-quinolinolato) (ortho-phenylphenolate)
Aluminum (III), bis (2-methyl-8-quinolinolato) (meth-phenylphenolato) aluminum (II
I), bis (2-methyl-8-quinolinolato) (para-
Phenylphenolato) aluminum (III), bis (2-
Methyl-8-quinolinolato) (2,3-dimethylphenolato) aluminum (III), bis (2-methyl-8-quinolinolato) (2,6-dimethylphenolato) aluminum (III), bis (2-methyl- 8-quinolinolato)
(3,4-dimethylphenolato) aluminum (III),
Bis (2-methyl-8-quinolinolato) (3,5-dimethylphenolato) aluminum (III), bis (2-methyl-8-quinolinolato) (3,5-di-tert-butylphenolato) aluminum (III) ), Bis (2-methyl-8)
-Quinolinolato) (2,6-diphenylphenolato) aluminum (III), bis (2-methyl-8-quinolinolato) (2,4,6-triphenylphenolato) aluminum (III), bis (2-methyl- 8-quinolinolato)
(2,3,6-trimethylphenolato) aluminum (I
II), bis (2-methyl-8-quinolinolato) (2,
3,5,6-tetramethylphenolato) aluminum (I
II), bis (2-methyl-8-quinolinolato) (1-naphthrat) aluminum (III), bis (2-methyl-8
-Quinolinolato) (2-naphthrat) aluminum (II
I), bis (2,4-dimethyl-8-quinolinolato)
(Ortho-phenylphenolato) aluminum (III),
Bis (2,4-dimethyl-8-quinolinolato) (para-
Phenylphenolato) aluminum (III), bis (2,
4-dimethyl-8-quinolinolato) (meta-phenylphenolato) aluminum (III), bis (2,4-dimethyl-8-quinolinolato) (3,5-dimethylphenolato) aluminum (III), bis (2 4-dimethyl-8
-Quinolinolato) (3,5-di-tert-butylphenolato) aluminum (III), bis (2-methyl-4-ethyl-8-quinolinolato) (para-cresolato) aluminum (III), bis (2-methyl) -4-methoxy-8-quinolinolato) (para-phenylphenolato) aluminum (III), bis (2-methyl-5-cyano-8-quinolinolato) (ortho-cresolato) aluminum (III),
Bis (2-methyl-6-trifluoromethyl-8-quinolinolato) (2-naphthrat) aluminum (III);

In addition, bis (2-methyl-8-quinolinolato) aluminum (III) -μ-oxo-bis (2-
Methyl-8-quinolinolato) aluminum (III), bis (2,4-dimethyl-8-quinolinolato) aluminum
(III) -μ-oxo-bis (2,4-dimethyl-8-quinolinolato) aluminum (III), bis (4-ethyl-
2-methyl-8-quinolinolato) aluminum (III)-
μ-oxo-bis (4-ethyl-2-methyl-8-quinolinolato) aluminum (III), bis (2-methyl-4
-Methoxyquinolinolato) aluminum (III) -μ-oxo-bis (2-methyl-4-methoxyquinolinolato)
Aluminum (III), bis (5-cyano-2-methyl-
8-quinolinolato) aluminum (III) -μ-oxo-
Bis (5-cyano-2-methyl-8-quinolinolato) aluminum (III), bis (2-methyl-5-trifluoromethyl-8-quinolinolato) aluminum (III) -μ
-Oxo-bis (2-methyl-5-trifluoromethyl-8-quinolinolato) aluminum (III) and the like.

Other host materials are disclosed in
Also preferred are phenylanthracene derivatives described in JP-A-12600 and tetraarylethene derivatives described in JP-A-8-12969.

The light emitting layer may also serve as an electron transporting layer. In such a case, tris (8-quinolinolato)
It is preferable to use aluminum or the like. These fluorescent substances may be deposited.

The light emitting layer is preferably a mixed layer of at least one kind of hole injecting and transporting compound and at least one kind of electron injecting and transporting compound, if necessary.
Further, it is preferable that a dopant is contained in the mixed layer. The content of the compound in such a mixed layer is 0.01 to 20% by volume, further 0.1 to 15% by volume.
% Is preferable.

In the mixed layer, a carrier hopping conduction path is formed, so that each carrier moves in a polarly advantageous substance, and carrier injection of the opposite polarity is less likely to occur, so that the organic compound is less susceptible to damage. This has the advantage that the element life is extended. Further, by including the above-described dopant in such a mixed layer, the emission wavelength characteristics of the mixed layer itself can be changed, the emission wavelength can be shifted to a longer wavelength, and the emission intensity is increased, The stability of the device can be improved.

The hole injecting and transporting compound and the electron injecting and transporting compound used in the mixed layer may be selected from the hole injecting and transporting compound and the electron injecting and transporting compound described below, respectively.

As the compound capable of injecting and transporting electrons, it is preferable to use a quinoline derivative, furthermore a metal complex having 8-quinolinol or a derivative thereof as a ligand, particularly tris (8-quinolinolato) aluminum (Alq3). It is also preferable to use the above-mentioned phenylanthracene derivatives and tetraarylethene derivatives.

As the compound for the hole injecting / transporting layer, it is preferable to use an amine derivative having strong fluorescence, for example, a triphenyldiamine derivative, a styrylamine derivative, or an amine derivative having an aromatic condensed ring.

The mixing ratio in this case depends on the respective carrier mobility and carrier concentration. In general, the weight ratio of the hole injection / transport compound / electron injection / transport compound is 1%.
/ 99-99 / 1, more preferably 10 / 90-90
/ 10, particularly preferably about 20/80 to 80/20.

The thickness of the mixed layer is preferably not less than the thickness corresponding to one molecular layer and less than the thickness of the organic compound layer. Specifically, the thickness is preferably 1 to 100 nm, more preferably 5 to 60 nm, particularly preferably 5 to 50 nm.

As a method for forming a mixed layer, co-evaporation in which evaporation is performed from different evaporation sources is preferable. However, when the vapor pressures (evaporation temperatures) are approximately the same or very close, they are mixed in advance in the same evaporation board. Alternatively, it can be deposited. In the mixed layer, it is preferable that the compounds are uniformly mixed, but in some cases, the compounds may exist in an island shape. The light-emitting layer is generally formed to a predetermined thickness by vapor-depositing an organic fluorescent substance or by dispersing and coating the resin in a resin binder.

Examples of the hole injecting and transporting compound include, for example, JP-A-63-295695 and JP-A-2-19.
1694, JP-A-3-792, JP-A5-
JP-A-234681, JP-A-5-239455,
JP-A-5-299174, JP-A-7-12622
No. 5, JP-A-7-126226, JP-A-8-
Various organic compounds described in, for example, Japanese Patent No. 100172 and EP0650955A1 can be used. For example, a tetraarylbendicine compound (triaryldiamine or triphenyldiamine: TPD), an aromatic tertiary amine, a hydrazone derivative, a carbazole derivative,
Triazole derivatives, imidazole derivatives, oxadiazole derivatives having an amino group, polythiophene and the like. These compounds may be used alone or in combination of two or more. When two or more kinds are used in combination, they may be stacked as separate layers or mixed.

The electron injecting and transporting compound includes quinoline derivatives such as organometallic complexes having 8-quinolinol such as tris (8-quinolinolato) aluminum (Alq3) or derivatives thereof as ligands, oxadiazole derivatives, perylene derivatives, and the like. A pyridine derivative, a pyrimidine derivative, a quinoxaline derivative, a diphenylquinone derivative, a nitro-substituted fluorene derivative, or the like can be used.

For forming the light emitting layer, the hole injection transport layer and the electron injection transport layer, a uniform thin film can be formed.
It is preferable to use a vacuum deposition method. When vacuum deposition is used, the amorphous state or the crystal grain size is 0.2 μm
The following homogeneous thin film is obtained. If the crystal grain size exceeds 0.2 μm, the light emission becomes non-uniform, the driving voltage of the device must be increased, and the charge injection efficiency is significantly reduced.

The conditions for vacuum deposition are not particularly limited.
The degree of vacuum is 0 ^-4 Pa or less, and the deposition rate is 0.01 to 1 nm /
It is preferable to set it to about sec. Further, it is preferable to form each layer continuously in a vacuum. If they are formed continuously in a vacuum, impurities can be prevented from adsorbing at the interface between the layers, so that high characteristics can be obtained. Further, the driving voltage of the element can be reduced, and the occurrence and growth of dark spots can be suppressed.

In the case where a plurality of compounds are contained in one layer when a vacuum evaporation method is used for forming each of these layers, it is preferable to co-deposit each boat containing the compounds by individually controlling the temperature.

The material for the hole injection electrode is preferably a material capable of efficiently injecting holes into the hole injection layer or the like, and is preferably a substance having a work function of 4.5 eV to 5.5 eV. Specifically, tin-doped indium oxide (ITO), zinc-doped indium oxide (IZO), indium oxide (In
₂ O ₃ ), tin oxide (SnO ₂ ) and zinc oxide (Zn
O) having a main composition of either of them is preferable. These oxides may deviate somewhat from their stoichiometric composition. The mixing ratio of SnO ₂ to In ₂ O ₃ is 1 to 20.
wt%, more preferably 5 to 12 wt%. Also, IZO
The mixing ratio of ZnO to In ₂ O ₃ is usually 12
About 32% by weight.

The hole injection electrode may contain silicon oxide (SiO ₂ ) in order to adjust the work function.
The content of silicon oxide (SiO ₂ ) is preferably about 0.5 to 10% by mol ratio of SiO _{2 to} ITO. S
The inclusion of iO ₂ increases the work function of ITO.

The electrode on the light extraction side has an emission wavelength band,
The light transmittance is usually 400 to 700 nm, particularly preferably 50% or more, more preferably 80% or more, and particularly preferably 90% or more for each emitted light. If the transmittance is too low, the light emission itself from the light emitting layer is attenuated, and it becomes difficult to obtain the luminance required for the light emitting element.

The thickness of the electrode is 50 to 500 nm, especially 50 to 500 nm.
The range of -300 nm is preferred. The upper limit is not particularly limited. However, if the thickness is too large, there is a fear that the transmittance is reduced or the layer is peeled off. If the thickness is too small, a sufficient effect cannot be obtained, and there is a problem in film strength at the time of production and the like.

As the negative electrode, in combination with an organic electron injection / transport layer or the like, the following electrode can be used as necessary as an electrode having electron injection properties. For example,
K, Li, Na, Mg, La, Ce, Ca, Sr, B
a, Sn, Zn, Zr or other metal element alone, or a binary or ternary alloy system containing them to improve stability, for example, Ag.Mg (Ag: 0.1 to 50 at%), A
l·Li (Li: 0.01 to 14 at%), In · Mg
(Mg: 50-80 at%), Al.Ca (Ca: 0.0
1 to 20 at%).

The thickness of the negative electrode thin film may be a certain thickness or more for sufficiently injecting electrons, and may be 0.1 nm or more, preferably 0.5 nm or more, particularly 1 nm or more. Also,
Although there is no particular upper limit, the film thickness is usually 1 to 50.
It may be about 0 nm.

The negative electrode (electron injecting electrode) does not need to be particularly limited because it does not need to have a low work function and has an electron injecting property when combined with an inorganic electron injecting and transporting layer. Can be used. Among them, in terms of conductivity and ease of handling, Al, Ag, In, Ti, Cu,
Au, Mo, W, Pt, Pd and Ni, especially Al, A
One or two or more metal elements selected from g are preferable.

In this case, the thickness of the negative electrode thin film may be a certain thickness or more capable of giving electrons to the inorganic electron injecting and transporting layer, and may be 50 nm or more, preferably 100 nm or more. There is no particular upper limit,
Usually, the film thickness may be about 50 to 500 nm.

The total thickness of the negative electrode and the protective layer is not particularly limited, but may be generally about 50 to 500 nm.

Further, in order to prevent deterioration of the organic layers and electrodes of the device, it is preferable to seal the device with a sealing plate or the like. The sealing plate adheres and seals the sealing plate using an adhesive resin layer in order to prevent moisture from entering. The sealing gas is A
An inert gas such as r, He, and N ₂ is preferable. Further, the moisture content of the sealing gas is preferably 100 ppm or less, more preferably 10 ppm or less, and particularly preferably 1 ppm or less. Although there is no particular lower limit for the water content, it is usually about 0.1 ppm.

The material of the sealing plate is preferably a flat plate, and may be a transparent or translucent material such as glass, quartz, and resin. Particularly, glass and resin are preferable. As such a glass material, an alkali glass is preferable from the viewpoint of cost. In particular, a soda glass material having no surface treatment can be used at a low cost, and is preferable. As the resin material, those exemplified for the following substrate are preferable.

The height of the sealing plate may be adjusted to a desired height by using a spacer. Examples of the material of the spacer include resin beads, silica beads, glass beads, and glass fibers, and glass beads are particularly preferable.

When a recess is formed in the sealing plate,
Spacers may or may not be used. The preferred size when used is within the above range,
Particularly, the range of 2 to 8 μm is preferable.

The adhesive is not particularly limited as long as it can maintain stable adhesive strength and has good airtightness, but it is preferable to use a cationic curing type ultraviolet curing epoxy resin adhesive. .

The substrate material is not particularly limited, and can be appropriately determined depending on the material of the electrodes of the organic EL structure to be laminated. For example, a metal material such as Al, or a transparent or transparent material such as glass, quartz, or resin. The material may be translucent or opaque. In this case, in addition to glass, ceramics such as alumina, metal sheets such as stainless steel are subjected to insulation treatment such as surface oxidation, and thermosetting resins such as phenolic resin And a thermoplastic resin such as polycarbonate.

The organic EL device of the present invention is generally used as a DC drive type or pulse drive type EL device, but may be driven by an AC drive. The applied voltage is usually 2 to 30
V.

As shown in FIG. 1, for example, the organic EL device of the present invention comprises a substrate 1, a color filter layer 2, a fluorescence conversion layer 3, a barrier layer 4, a hole injection electrode 5, a hole injection transport layer 6, and a light emitting layer 7. / Electron injection / transport layer 8 / negative electrode (electron injection electrode) 9 may be sequentially laminated. Further, as shown in FIG. 2, the substrate 1 / negative electrode (electron injection electrode) 9 / electron injection / transport layer 8 / light emitting layer 7 / hole injection / transport layer 6 / hole injection electrode 5 / fluorescence conversion layer 3 / color filter layer 2 / barrier layer 4 may be formed in an inversely laminated configuration in which the layers are sequentially laminated. In the configuration of FIG. 2, the light extraction side is the hole injection electrode side opposite to the substrate. In this case, the barrier layer 4 may be omitted. 1 and 2, a drive power supply 9 is connected between the hole injection electrode 5 and the negative electrode 9.

The devices of the present invention may be stacked in multiple layers in the film thickness direction. With such an element structure, it is also possible to adjust the color tone of the emitted light and to make it multi-colored.

The organic EL element of the present invention can be applied to various optical applications such as an optical pickup used for memory read / write, a relay device in a transmission line of optical communication, a photocoupler, etc. in addition to a display application. Can be used for devices.

[0079]

<Example 1> On a 7059 glass substrate manufactured by Corning Incorporated, a blue filter layer, a red filter layer,
As a green filter layer, phthalocyanine blue (blue), quinacridone red (red), phthalocyanine blue and quinacridone red (green) were each formed by a mask deposition method.

The pressure during the deposition was 1 × 10 ⁻⁴ Pa or less, and the thickness of each filter layer was 400 nm.

While maintaining the reduced pressure, coumarin 6 having the following structure was applied to the green light-emitting portion at a deposition rate of 0.1 nm / sec.
It was evaporated to a thickness of nm to obtain a green fluorescence conversion layer.

[0082]

Embedded image

Further, a luminogen (or rhodamine 6) was applied to the red light emitting portion at a deposition rate of 0.1 nm / sec.
It was deposited to a thickness of nm to obtain a red fluorescence conversion layer.

Next, using SiO ₂ as a target, RF
By the sputtering method, the barrier layer is formed at a deposition rate of 10 nm / min.
A film was formed to a thickness of 30 nm. The sputtering gas at this time is A
The pressure during film formation was 0.5 Pa at r 100 sccm. The temperature was room temperature, the input power was 500 W at a frequency of 13.56 MHz, and the distance between the substrate and the target was 5 cm. The composition of the formed barrier layer was SiO _1.9 .

Next, an ITO transparent electrode (hole injection electrode)
Was formed and patterned so as to form pixels of 64 dots × 7 lines (200 × 200 μm per pixel) with a film thickness of 85 nm. Then, the substrate on which the patterned hole injection electrode was formed was subjected to ultrasonic cleaning using a neutral detergent, acetone and ethanol, pulled up from boiling ethanol, and dried. Thereafter, UV / O ₃ cleaning was performed.

Next, the vessel was again fixed to the substrate holder of the vacuum evaporation apparatus, and the pressure in the tank was reduced to 1 × 10 ⁻⁴ Pa or less.

While maintaining the reduced pressure state, N,
N'-diphenyl-N, N'-bis [N- (4-methylphenyl) -N-phenyl- (4-aminophenyl)]
-1,1'-biphenyl-4,4'-diamine (ATP
34) was deposited at a deposition rate of 0.2 nm / sec to a thickness of 40 nm to form a hole injection layer.

[0088]

Embedded image

Next, N, N'-bis (m-
Methylphenyl) -N, N'-diphenyl-1,1'-
Biphenyl-4,4'-diamine (TPD27) was deposited at a deposition rate of 0.2 nm / sec to a thickness of 20 nm to form a hole transport layer.

[0090]

Embedded image

Further, the TPD 27 is kept under reduced pressure.
And a 1: 1 mixture of Alq3 and DSMA having the following structure, doped with 2.5% by volume, was deposited to a thickness of 40 nm at an overall deposition rate of 0.2 nm / sec. And

[0092]

Embedded image

Next, while maintaining the reduced pressure, AlLi (L
i: 7 at%) to a thickness of 1 nm, followed by Al
Evaporation was performed to a thickness of 0 nm to form a negative electrode for an electron injection electrode and an auxiliary electrode.

Finally, glass sealing was performed to obtain an organic EL display device.

The organic EL device thus obtained is
Since it was formed by the mask evaporation method, a filter layer of three primary colors could be formed in a pixel of 200 μm square. The light emitted from the light emitting layer is 400 to 700.
It was white light in the wavelength band of nm.

[0096] Ten samples were prepared, and
Each pixel was driven in a predetermined pattern at a constant current density of 10 mA / cm ² , and the display surface was visually observed. As a result, the display screen was superior in expressing color and saturation compared to those using conventional color filters. Was obtained. Further, since the formation of the color resist material and the overcoat is not required, the cost can be reduced by about 30% or more.

Example 2 Al was vapor-deposited to a thickness of 200 nm on a 7059 glass substrate manufactured by Corning Co., Ltd. by vacuum vapor deposition, followed by vapor deposition of AlLi (Li: 7 at%) to a thickness of 1 nm. To form a negative electrode for the auxiliary electrode and the electron injection electrode.

Further, while maintaining the reduced pressure, the TPD 27
And Alq3 in a ratio of 1: 1 with DSMA
Was deposited at a thickness of 40 nm at a total deposition rate of 0.2 nm / sec to form a light emitting layer.

By vapor deposition, 4,4 ', 4 "-tris (-N- (3-methylphenyl) -N-phenylamino) triphenylamine (m-MTDATA) was 55 nm at a vapor deposition rate of 0.1 nm / sec. To form a hole injecting layer, N, N′-diphenyl-N, N′-m-tolyl-4,4′-diamino-1,1′-biphenyl (T
PD) was deposited at a deposition rate of 0.1 nm / sec to a thickness of 20 nm to form a hole transport layer.

Next, the film was transferred to a sputtering apparatus, and an ITO transparent electrode (hole injection electrode) was formed and patterned so as to constitute a pixel of 85 dots in thickness and 64 dots × 7 lines (200 × 200 μm per pixel).

While maintaining the reduced pressure, coumarin 6 was vapor-deposited on the green light-emitting portion to a thickness of 400 nm at a deposition rate of 0.1 nm / sec to form a green fluorescence conversion layer, and luminogen (or rhodamine 6) was deposited on the red light-emitting portion. Then, vapor deposition was performed at a vapor deposition rate of 0.1 nm / sec to a thickness of 400 nm to obtain a red fluorescence conversion layer.

Next, phthalocyanine blue (blue), quinacridone red (red), phthalocyanine blue and quinacridone red (green) were formed by a mask vapor deposition method as a blue filter layer, a red filter layer, and a green filter layer. The thickness of each filter layer was 400 nm.

Next, using SiO ₂ as a target, RF
By the sputtering method, the barrier layer is formed at a deposition rate of 10 nm / min.
A film was formed to a thickness of 30 nm. The sputtering gas at this time is A
The pressure during film formation was 0.5 Pa at r 100 sccm. The temperature was room temperature, the input power was 500 W at a frequency of 13.56 MHz, and the distance between the substrate and the target was 5 cm. The composition of the formed barrier layer was SiO _1.9 .

Finally, glass sealing was performed to obtain an organic EL display device.

When the obtained organic EL display was evaluated in the same manner as in Example 1, almost the same results as in Example 1 were obtained. Further, almost no damage to the organic EL element due to the formation of the color filter layer was observed.

<Example 3> An organic EL prepared in the same manner as in Example 2 except that the sealing plate was changed from a glass plate to a PET (polyethylene terephthalate) film coated with SiO _2. The display device was evaluated for luminance half-life together with the display device of Example 2, and the results were almost the same. It was found that the display device was sufficiently practicable even when a PET sealing plate was used.

[0107]

As described above, according to the present invention, light of a color not included in the light emitted from the light-emitting layer or light of an insufficient color can be supplemented, and the yield can be increased with high quality and low cost. In addition, it is possible to realize an organic EL display device which is capable of preventing disconnection of wiring due to a difference in level of a color filter.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a basic configuration of an organic EL device of the present invention.

FIG. 2 is a schematic cross-sectional view showing another basic configuration (reverse stacking) of the organic EL device of the present invention.

[Explanation of symbols]

 Reference Signs List 1 substrate 2 color filter layer 3 barrier layer 4 hole injection electrode 5 hole injection and transport layer 6 light emitting layer 7 electron injection and transport layer 8 negative electrode (electron injection electrode)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05B 33/10 H05B 33/10 33/14 33/14 A F term (Reference) 3K007 AB00 AB04 AB13 AB18 BB00 BB01 BB02 BB04 BB06 CA01 CA04 CA05 CB01 DA00 DB03 EB00 FA01 FA02 4K029 AA11 BA62 BB03 BC07 BD00 CA01 DB06 EA01 GA03 HA01 5C094 AA42 AA44 AA60 BA27 EA05 EB02 ED02 HA08 5G435 AA00 AA17 BB05 GG05

Claims (11)

[Claims] 1. A substrate having a color filter layer, a fluorescence conversion layer, a barrier layer, a hole injection electrode and an electron injection electrode in order on a substrate, and an organic layer involved in a light emitting function between these electrodes. The organic EL display device, wherein the color filter layer is formed by an evaporation method. 2. The organic EL display according to claim 1, wherein the color filter layer is formed of a pigment. 3. The film thickness of the color filter layer is 20.
2. The organic EL display according to claim 1, which has a thickness of not more than 00 nm. 4. The organic EL display device according to claim 1, wherein said vapor deposition method is a mask vapor deposition method. 5. The organic EL display device according to claim 1, wherein the light emitted from the light emitting layer is monochromatic light having a light emission wavelength bandwidth of 430 to 530 nm or less. 6. A color filter comprising: an electron injection electrode, a hole injection electrode, a fluorescence conversion layer, and a color filter layer in this order on a substrate; and an organic layer involved in a light emitting function between the electrodes. An organic EL display device in which the filter layer is formed by a vapor deposition method. 7. The organic EL display according to claim 6, wherein the color filter layer is formed of a pigment. 8. The film thickness of the color filter layer is 20
The organic EL display device according to claim 6 or 7, wherein the thickness is not more than 00 nm. 9. The organic EL display device according to claim 6, wherein said vapor deposition method is a mask vapor deposition method. 10. The organic EL display device according to claim 6, wherein the emission light obtained from the emission layer is monochromatic emission having an emission wavelength bandwidth of 430 to 530 nm or less. 11. A method according to claim 6, further comprising a resin sealing structure.
0 organic EL display device.