JP2001223076A - Manufacturing method of organic electric field light emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain a manufacturing method of an organic electric field light emitting element which has an excellent durability with an organic layer which has a strong adhesion power to a substrate and a uniform quality. SOLUTION: The organic layer having a single-layer or a multi-layer structure is formed by forming a 1st electrode on a substrate and by subsequently applying a liquid which contains a compound which forms an organic layer on the 1st electrode and by drying it. And a 2nd electrode is formed on the organic layer to manufacture the organic electric field light emission element. Wherein, an energy ray is irradiated on the 1st electrode before formation of the organic layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing an organic electroluminescent device. More specifically, the present invention relates to a method of manufacturing an organic electroluminescent device having a strong adhesion to a substrate and having a uniform organic layer and excellent durability.

[0002]

2. Description of the Related Art In recent years, organic electroluminescent devices using organic compounds (hereinafter referred to as "light emitting devices") are expected to be used as full-color display devices because of their self-luminous type and clear display. Much development has been done.

[0003] Generally, a light emitting element comprises a light emitting layer and a pair of opposing electrodes sandwiching the light emitting layer. When an electric field is applied between the opposing electrodes of such a light emitting element, electrons are injected from the cathode side, and holes are injected from the anode side. These injected electrons and holes recombine in the light emitting layer, and emit energy as light when the energy level returns from the conduction band to the valence band. The light-emitting layer of a light-emitting element plays an important part in luminous efficiency and its stability. In the case of a light-emitting element using an organic compound as a light-emitting material, an arbitrary color can be easily obtained depending on the molecular structure.

Various light-emitting devices have been studied so far for the purpose of improving the luminous efficiency and converting the luminous wavelength. For example, low-molecular dyes (host compounds) such as aluminum quinolinol complex (Alq ₃ ) and distyrylbiphenyl
An organic layer-stacked light-emitting element including a thin film of a light-emitting layer doped with a fluorescent dye having high luminous efficiency, such as a dicyanomethylenepyran derivative (DCM), perylene, and quinacridone, may be mentioned.

In general, a thin film of a low molecular compound is formed by a vacuum evaporation method. However, it is difficult to obtain a uniform and defect-free thin film by the vacuum evaporation method, and the formed thin film has problems in stability and strength. . For example, when heat is applied to the light emitting element, the organic compound molecules in the thin film are crystallized and aggregated, so that the organic compound molecules cannot partially contact the electrode, and a dark spot is generated. In addition, when the organic layer of the light emitting element has a multilayer structure, the vacuum evaporation method requires time to form a thin film,
Poor production efficiency.

On the other hand, there is a light emitting device using a high molecular weight organic compound such as a polyethylene dioxythiophene compound for a hole injection / transport layer. Such high molecular organic compounds are
The hole injecting and transporting layer can be formed by dissolving or dispersing in water, applying this coating solution on an electrode, forming a film, and heating the film. In addition, polyarylene vinylene (poly
There is a light emitting element using a high molecular weight organic compound such as an arylene vinylene) compound for a light emitting layer. Such a high-molecular-weight organic compound is not soluble in an organic solvent and its precursor is soluble in water, an alcohol-based solvent and a glycol-based solvent,
A coating solution dissolved in a solvent in the form of a salt is applied on the electrode, and after forming the film, the functional group is eliminated and conjugated by heating to form a light emitting layer.

However, since the contact angle of the liquid on the surface of the electrode on which the hole injection / transport layer or the light emitting layer is formed is large, even if the coating liquid is applied on the electrode by a known method, the pattern of the light emitting surface is not obtained. There were problems such as poor cutting performance and unevenness in film thickness.

Japanese Patent Application Laid-Open No. 10-214682 discloses a method of forming a light emitting element without exposing a substrate to the atmosphere, and discloses a method of treating a substrate by irradiation with ultraviolet rays or plasma. However, this prior art does not have a technical idea of reducing the contact angle of the liquid on the substrate surface by irradiation with energy rays.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing a light-emitting device having a strong adhesion to a substrate and having a uniform organic layer and excellent durability.

[0010]

Means for Solving the Problems In view of the present situation, the present inventors have conducted intensive research and have found that the first
By irradiating the electrode with energy rays, the surface of the electrode can be modified, that is, the wettability of the liquid containing the organic layer-forming compound can be improved, and the light-emitting element having a strong and uniform organic layer with the substrate. Was obtained, and the present invention was achieved.

Thus, according to the present invention, a first electrode is formed on a substrate, and then a liquid containing an organic layer forming compound is applied and dried on the first electrode to form an organic layer having a single-layer or multilayer structure. A method for manufacturing a light-emitting element is provided, in which a light-emitting element is manufactured by forming a second electrode on the organic layer and irradiating an energy ray on the first electrode before forming the organic layer. .

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A method for manufacturing a light emitting device according to the present invention comprises:
The present invention can be applied to manufacture of any type of light emitting device. 2 and 3 are schematic cross-sectional views showing the structure of a general light emitting device. The light emitting device shown in FIG.
An electrode 7, a light-emitting layer 9, and a cathode (second electrode) 10. The light emitting device shown in FIG. 3 has a structure in which a hole injection / transport layer 8 is formed between the anode 7 and the light emitting layer 9 in the light emitting device shown in FIG. In FIG. 2, the light emitting layer 9 is combined with the light emitting layer 9 and the hole injection transport layer 8 in FIG.
Also called 1.

The hole injection transport layer 8 is a layer containing a hole injection material and / or a hole transport material. This has a function of efficiently injecting holes from the anode and efficiently transmitting the injected holes to the light emitting layer 9. This hole injection transport layer 8
May have a two-layer structure of a layer for injecting holes and a layer for transporting holes.

In the light emitting device of FIGS. 2 and 3, an electron injection / transport layer (not shown) may be formed between the light emitting layer 9 and the cathode 10, and this layer is also a layer for injecting electrons. And a two-layer structure of a layer for transporting. This has a function of efficiently injecting electrons from the cathode and efficiently transmitting the injected electrons to the light emitting layer 9. Such a light-emitting element is one of preferred embodiments of the present invention because a light-emitting element having a multilayer structure can prevent reduction in light emission luminance and element life due to quenching.

According to the method of manufacturing a light emitting device of the present invention, a first electrode is formed on a substrate, and then a liquid containing an organic layer forming compound is applied and dried on the first electrode to form an organic layer having a single-layer or multilayer structure. When forming the second electrode on the organic layer to manufacture a light emitting element, the surface of the first electrode formed before forming the organic layer is irradiated with energy rays.

When the surface of the first electrode is irradiated with energy rays, water, oxygen, etc. on the surface of the first electrode are decomposed on the surface of the first electrode, and the chemically adsorbed water is exposed, and the chemical on the outermost surface of the first electrode is exposed. Adsorbed water increases. Thereby, the property of the surface of the first electrode changes from hydrophobic to hydrophilic, so that the wettability of the liquid containing the organic layer forming compound on the first electrode is improved.

Typical chemical bond energies of organic compounds are CC: 348 kJ / mol, C = C: 60
8 kJ / mol, CH: 415 kJ / mol and C
= O: 725 kJ / mol. Ultraviolet light is very effective energetically for breaking these chemical bonds.

The energy beam irradiated in the present invention is not particularly limited as long as it can cut the above-mentioned chemical bond energy. Specifically, ultraviolet light is mentioned,
It is energetically favorable. In addition, wavelength 3 among ultraviolet rays
It is preferably 50 to 150 nm, and 300 to 150 n
m are particularly preferred. When the wavelength of the ultraviolet ray exceeds 350 nm, it is not preferable because the surface modification of the first electrode becomes difficult and the incineration treatment of the organic matter which is the contaminant of the first electrode cannot be performed effectively.

Examples of the energy ray source include a low-pressure mercury lamp and an excimer lamp. Specifically, a low-pressure mercury lamp having a wavelength (λ) of 254 nm and 185 nm (the emission line energy is 471 kJ / mo, respectively)
l and 647 kJ / mol), and wavelength 3
08 nm (XeCl ^* ), 227 nm (KrCl ^* ), 1
72 nm (Xe ₂ ^* ), 126 nm (Ar ₂ ^* ) and 14 nm
An excimer lamp of 6 nm (Kr ₂ ^* ) may be used. Among them, an excimer lamp having a wavelength of 172 nm (Xe ₂ ^* ) is preferable. The irradiance of the energy ray may be set to such an extent that the surface of the electrode is modified, that is, the wettability of the liquid containing the organic layer forming compound is improved.

The irradiation time of the energy ray depends on the irradiance of the energy ray and other irradiation conditions, but is usually about 1 minute to 1 hour. The degree of improvement in the wet spreading property of the organic layer forming compound-containing liquid on the first electrode is as follows.
It is proportional to the dose. Specifically, the wavelength of 172 nm (X
The excimer lamp of e ₂ ^* ) improves the hydrophilicity of the surface of the first electrode with shorter irradiation.

Further, according to the method of manufacturing a light emitting device of the present invention, it is possible to irradiate only a region of the first electrode which requires surface modification with an energy beam, and to improve the wet spreading property of the liquid only in that region. A known masking technique can be used for such partial irradiation of energy rays. Therefore, in the case where an insulator pattern for dividing the light emitting region exists in the light emitting element, the surface modification of the first electrode can be performed by masking without causing a large damage to the insulator pattern by energy rays. It can be carried out.

As a method for evaluating the wet spreading property of the liquid on the surface of the first electrode, specifically, there is a method for measuring a contact angle between a droplet (for example, a water droplet) and the surface of the first electrode. Generally, the contact angle with a water droplet differs depending on the target material. For example, an inorganic material such as glass is about 20 to 30 °, a resin is about 70 to 90 °, and a water-repellent silicone resin is about 9 to 30 °.
0 ° or more. Materials whose contact angle with water is 10 ° or less
There are only a few materials, such as a water-absorbing material and a material coated with a surfactant.

FIG. 1 shows an example of a method for manufacturing a light emitting device of the present invention.
It will be described based on. FIG. 1 is a schematic view showing an energy ray irradiation and an organic layer forming process in the method for manufacturing a light emitting device of the present invention. First, the glass plate 1 on which the ITO (indium tin oxide) film 2 is formed is washed with a surfactant, water and an organic solvent to remove dirt attached to the surfaces of the glass plate 1 and the ITO film 2. (See FIG. 1A). Next, the surface of the ITO film 2 is irradiated with ultraviolet rays 3,
The surface of the O film 2 is modified (see FIG. 1B).

An organic layer forming compound-containing liquid 4 is applied on the ITO film 2 (see FIG. 1C), and is dried by heating to obtain an organic layer 5 (see FIG. 1D). Forming a second electrode on the organic layer 5, further forming a glass substrate,
A light-emitting element is obtained by performing sealing treatment with an epoxy resin, a spacer, or the like (not shown). In the above process, the contact angle between the ITO film surface and water is several tens of degrees or more before the irradiation with the energy beam, but the contact angle decreases after the irradiation with the energy beam, and the polar solvent such as water or alcohol is used. Will not play.

Next, each constituent material of the light emitting device of the present invention will be described. The substrate, the first electrode, and the second electrode are not particularly limited as long as they have mechanical strength and thermal strength that are usually used for this type of substrate and electrode. The materials of the substrate, the first electrode, and the second electrode are selected according to the configuration of the light emitting element.

That is, in the light emitting element, when light emitted from the light emitting layer 9 is emitted from the substrate 6 side, the substrate 6 and the first electrode 7 are respectively a transparent substrate and a transparent electrode, and the second electrode 10 is a reflective electrode. Alternatively, it is preferable to provide a reflection film (not shown) on a surface of the second electrode 10 that is not adjacent to the organic layer 11. Conversely, in the light emitting element,
When light emitted from the light emitting layer 9 is emitted from the second electrode 10 side, the first electrode 7 is used as a reflective electrode,
It is preferable to provide a reflection film (not shown) between the electrode 7 and the substrate 6. At this time, the transparency of the substrate 6 does not matter.

As the structure of the light emitting element, it is preferable that light emitted from the light emitting layer is emitted from the substrate side in terms of light extraction efficiency. Therefore, a transparent substrate is preferable as the substrate, and examples of the material include glass, quartz, and transparent plastics (such as polyester, polymethacrylate, polycarbonate, and polysulfone). Further, an insulating layer, a circuit, or the like for distinguishing a light-emitting region may be formed over these substrates.

As a material of the transparent electrode, a transparent conductive material having a large work function (4 eV or more) is preferable.
ITO (indium tin oxide), SnO ₂ , CuI, Z
Organic conductive resins such as nO and CuAlO ₂ and polythiophene and polypyrrole are exemplified. When the substrate is a transparent substrate, ITO is particularly preferable in terms of excellent workability.

As the material of the reflective electrode, a conductive material having a small work function (4 eV or less) is preferable. For example, metals such as magnesium, calcium, tin, lead, titanium, yttrium, lithium, ruthenium, manganese and aluminum, and the like, These alloys are mentioned.
Alloys include magnesium / silver, magnesium / indium and lithium / aluminum. The ratio of these alloys is selected depending on the temperature, atmosphere, degree of vacuum, and the like of the evaporation source.

As a method for forming the transparent electrode and the reflective electrode, any known method can be applied, but a vapor deposition method and a sputtering method are particularly preferable. Further, these electrodes may have a layer structure of two or more layers. The thicknesses of the transparent electrode and the reflective electrode are usually about 10 nm to 1 μm and about 10 nm to 1 μm, respectively.

The organic layer may be composed of only a single-layer or multilayer light-emitting layer as described above, but if necessary, a hole transport layer and a hole injection layer (together, a hole injection layer) Layer), and an electron transporting layer and an electron injecting layer (together, an electron injecting and transporting layer). As the organic layer forming compound-containing liquid,
Materials constituting each of the above-mentioned layers, that is, light-emitting materials, hole-transport materials, hole-injection materials, electron-transport materials, and liquids containing the electron-injection materials, respectively, may be mentioned. These liquids may be separately prepared to form the respective layers, or the respective materials may be mixed based on a light emitting material.

The organic layer forming compound-containing liquid may be mixed with another high molecular weight organic compound in order to improve the film-forming property and prevent pinholes in the film. In addition, a known light emitting material or a dopant material may be mixed with the liquid containing the organic layer forming compound for the light emitting layer in order to improve the light emitting characteristics of the light emitting material (including the host material).

As the high molecular weight organic compound as a light emitting material, a conjugated high molecular weight organic compound or a precursor thereof is preferable from the viewpoint of excellent durability. Among them, polyarylene vinylene or a precursor thereof is preferable from the viewpoint of excellent processability. preferable.

As polyarylene vinylene, for example,
Poly (p-phenylenevinylene) (PPV), poly (2,5-dimethoxy-1,4-phenylenevinylene)
(MO-PPV), poly (2,5-bishexyloxy-1,4-phenylene- (1-cyanovinylene)) (C
N-PPV) and poly (2-methoxy-5- (2'-
Ethylhexyloxy) -p-phenylenevinylene)
Derivatives such as (MEH-PPV). Some of the above polyarylene vinylenes have precursors that are conjugated by the release of a functional group by heating. Therefore, after forming a polyarylene vinylene precursor film, an inert gas (for example, Heating in a nitrogen gas atmosphere (for example, 15
(0 ° C., 8 hours) to obtain a polyarylene vinylene film.

Polyarylenevinylene (particularly, PPV derivative) or its precursor is soluble in water or an organic solvent, and is easy to process and can be polymerized. Is preferred because Polyarylenevinylene is also a conductive polymer in which the precursor has strong fluorescence and the π electrons of the double bond are non-polarized on the polymer chain. The π-π ^* energy gap can be changed by changing the molecular structure by introducing a substituent. That is, the emission color can be changed, and a high-performance light-emitting element can be obtained. The above high molecular weight organic compound also functions as a hole injection transport material.

Examples of the above-mentioned known light emitting materials and dopant materials include metal oxinoid compounds (8-hydroxyquinoline metal complex), butadiene derivatives, coumarin derivatives, dicyanomethylenepyran derivatives, fluorescein derivatives, perylene derivatives, perinone derivatives. , Aminopyrene derivatives, benzoxazole derivatives, oxadiazole derivatives, oxazole derivatives, thiadiazole derivatives, styrylamine derivatives, bisstyrylbenzene derivatives and tristyrylbenzene derivatives.

The hole transporting material and the hole injecting material may be any of an organic compound and an inorganic compound, and are used as a hole transporting material and a hole injecting material in known photoconductive materials and light emitting devices. Any of these can be used.

Examples of the above organic compounds include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives,
Biphenylenediamine derivative, binaphthylenediamine derivative, arylamine derivative, oxazole derivative, styrylanthracene derivative, fluorenone derivative, hydrazone derivative, stilbene derivative, polyvinylcarbazole, polysilane, polythiophene derivative, polyethylene dioxythiophene-polyethylene sulfonic acid mixture, polypyrrole derivative However, the present invention is not limited thereto. Among the above organic compounds, those containing an organic conductive resin such as polyethylene dioxythiophene are particularly preferable. Examples of the inorganic compound include p-type hydrogenated amorphous silicon and p-type hydrogenated amorphous silicon.
Hydrogenated amorphous silicon carbide, p-type hydrogenated microcrystalline silicon carbide, p-type zinc selenide, p-type zinc sulfide and the like.

The electron transporting material and the electron injecting material may be any of an organic compound and an inorganic compound, and may be any of those used as electron transporting materials and electron injecting materials in known photoconductive materials and light emitting devices. Can be selected and used.

Examples of the above organic compounds include oxadiazole derivatives, triazole derivatives, benzoquinone derivatives, naphthoquinone derivatives, anthraquinone derivatives, tetracyanoanthraquinodimethane derivatives, diphenoquinone derivatives, fluorenone derivatives, and metal oxinoid compounds (8-hydroxy Quinoline metal complex). Examples of the inorganic compound include n-type hydrogenated amorphous silicon carbide, n-type zinc sulfide, and n-type zinc selenide.

The liquid containing the organic layer forming compound is preferably a liquid in which the organic layer forming compound is dissolved or dispersed in a solvent. As the solvent, any of a polar solvent and a non-polar solvent may be used, but a polar solvent that can make use of the effect of improving the wettability (hydrophilicity) obtained by modifying the surface of the first electrode with energy rays is preferable. .

Examples of the polar solvent include water, alcohol solvents such as methanol, ethanol, 1-propanol and 2-propanol, glycol solvents such as ethylene glycol and glycerin (polyhydric alcohol solvents), and N, N-dimethylformamide. , Dimethylsulfoxide, dimethylimidazoline, N-methylpyrrolidone, and the like, and these may be used as a mixture.
Among these, a solvent containing at least one of water, an alcohol solvent and a glycol solvent is preferable.

The liquid containing an organic layer forming compound may contain a light stabilizer, if necessary, for the purpose of enhancing the durability of the organic layer.
Additives such as antioxidants, pH adjusters, preservatives and structural stabilizers may be added

The organic layer of the light emitting device according to the present invention can be formed by any method as long as it is a general thin film coating method, and the effect is exhibited without any problem. For example, casting, spin coating,
It can be formed on the first electrode by a solution coating method such as a blade coating method, a microgravure coating method and a dipping method, and an inkjet method. When the organic layer has a multilayer structure, the second layer does not necessarily need to be a solution coating method, such as a casting method, a spin coating method,
It can be formed by a solution coating method such as a blade coating method, a microgravure coating method and a dipping method, an ink jet method, a vapor deposition method and the like. The thickness of the light emitting layer is usually about 5 nm to 5 μm.

The hole transport layer, the hole injection layer, the hole injection and transport layer, the electron transport layer, the electron injection layer and the electron injection and transport layer
Like the light-emitting layer, any of them can be formed by a known method, and the thickness of each of them is usually 5 nm to 5 μm.
It is about.

[0046]

EXAMPLES The present invention will be described more specifically with reference to examples, but the present invention is not limited by these examples.

Example 1 (Confirmation of Cleaning Effect of Transparent Electrode on Substrate) ITO (Indium Tin Oxide) with a Sheet Resistance of 15Ω / □
The coated glass substrate (ITO film thickness: 1600 °) was ultrasonically washed with a surfactant, water and isopropanol and dried. When the contact angle of water on the ITO film surface was measured immediately after drying, the contact angle, which was 90 ° before the cleaning treatment, was reduced to 30 °.

An ITO-coated glass substrate (hereinafter referred to as an “ITO substrate”), which has been subjected to ultrasonic cleaning in the same manner as described above,
UV irradiation device (excimer lamp, λ = 172 nm (X
e ₂ ), irradiance 10 mW / cm ² , 695 kJ / mo
Using 1), ultraviolet rays were irradiated for 30 minutes. After irradiation I
When the contact angle of water on the surface of the TO film was measured, it was 5 to 20 °.
Had fallen.

Example 2 (Production 1 of light emitting device) p-xylylenebis (tetrahydrothiophenium chloride) 1, which is a monomer obtained by reacting α, α'-dichloro-p-xylene with tetrahydrothiophene
7.8 g of acetone (50 ml) / H ₂ O (89 ml)
, And the solution was cooled to 0 ° C. and replaced with Ar gas for 1 hour. 0.5 M LiOH
An aqueous solution (101 ml) was added at 0 ° C. while replacing the Ar gas. Next, the mixture was stirred vigorously for 20 minutes while maintaining the solution temperature at 0 ° C.
The reaction was stopped by adding 1 ml. The resulting viscous liquid was transferred into a dialysis membrane (Spectrapore membrane, Spectrapore membrane, cut-off molecular weight 6,000 to 8,000), dialyzed in water for 3 days, and salts and reactants as low molecular weight products were obtained. And purified polymer intermediate (precursor of PPV)
(See the following formula).

[0050]

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Using this concentrated solution, a solid concentration of 1 wt%
Was prepared in methanol. The prepared solution was spin-coated (2,000 rpm) on the ITO transparent electrode (first electrode 7) of the ITO substrate irradiated with ultraviolet rays in the same manner as in Example 1.
m, 30 sec) and dried under reduced pressure to obtain a PPV precursor film. Next, the precursor film was heated at 150 ° C. for 8 hours under a nitrogen stream.
By heat-treating for a time, a polyphenylenevinylene film (PPV film, light emitting layer 9) having a thickness of 100 nm was obtained. Further, when the film thickness of the PPV film formed in the same manner as described above was measured at a plurality of points, the distribution was 100 ± 5 nm.

Next, 0.9 n of LiF was formed on the PPV film.
m and Al were deposited to a thickness of 100 nm to form a second electrode 10 to obtain a light emitting device. The deposition conditions were as follows: the ultimate vacuum was 3 × 10 ⁻⁶ Torr, and the substrate temperature was room temperature. Also,
The deposition rate is 0.1 to 0.2 ° / sec for LiF,
In the case of Al, it was set to 4 to 5 ° / sec.

The ITO film of the light emitting device thus prepared was used as an anode, Al
Using the electrode film as a cathode, a DC electric field was applied between the two electrodes at room temperature and in the air to cause the light emitting layer to emit light. The light emission luminance was measured using a luminance meter. The maximum luminance was 90 cd / d at a driving voltage of 12 V. Green emission of m ² was observed. Further, the above element was sealed in a nitrogen gas atmosphere using a glass plate, an epoxy resin and a spacer, and the initial luminance was 5% at room temperature.
Continuous emission was performed at 0 cd / m ² , and the half-life of the emission luminance (time until the luminance reached 25 cd / m ² ) was measured. The half-life was 60 hours.

Comparative Example 1 The procedure of Example 1 was repeated, except that no ultraviolet light was applied.
A TO substrate (ITO film thickness: 1600 °, contact angle of water on the ITO film surface: 30 °) was obtained. A PPV film (thickness: 100 nm, light-emitting layer 9) was formed on the ITO transparent electrode (first electrode 7) of the obtained substrate in the same manner as in Example 2. Further, when the film thickness of the PPV film formed in the same manner as described above was measured at a plurality of points, the distribution was 100 ± 20 nm. Then, in the same manner as in Example 2, 1 nm of LiF and 1
The second electrode 10 was formed by vapor deposition of 00 nm to obtain a light emitting device.

The light-emitting luminance and half-life of the fabricated light-emitting device were measured in the same manner as in Example 2.
Green light emission with a maximum luminance of 90 cd / m ² was observed at a driving voltage of V. In the light-emitting element, the dark spot grew quickly, and the half-life was about 1 hour.

Example 3 (Production of Light-Emitting Element 2) In the same manner as in Example 2, an ITO substrate irradiated with ultraviolet rays was obtained. A PPV film (hole injection / transport layer 7) was formed on the ITO transparent electrode (first electrode 7) of the obtained substrate in the same manner as in Example 2.
I got On this film, cyanopolyphenylenevinylene (C
A chloroform solution of N-PPV (see the following structural formula) was spin-coated (2000 rpm, 30 sec) and dried under reduced pressure to obtain a 70-nm-thick CN-PPV film (light-emitting layer 9). Further, the PPV film / CN- formed in the same manner as above.
When the thickness of the PPV film was measured at a plurality of points, 170 ± 10
nm. Then, as in Example 2, C
0.9 nm of LiF and 100 n of Al on the N-PPV film
The second electrode 10 was formed by vapor deposition to obtain a light emitting device.

[0057]

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The emission luminance and half-life of the fabricated light-emitting device were measured in the same manner as in Example 2.
At a driving voltage of V, red light emission with a maximum luminance of 40 cd / m ² was observed. The half life was 50 hours.

Comparative Example 2 The procedure of Example 1 was repeated, except that no ultraviolet light was applied.
A TO substrate (ITO film thickness: 1600 °, contact angle of water on the ITO film surface: 30 °) was obtained. On the ITO transparent electrode (first electrode 6) of the obtained substrate, the PPV film /
A CN-PPV film (the hole injection transport layer 8 and the light emitting layer 9) was formed. Further, the PPV film formed in the same manner as described above /
When the thickness of the CN-PPV film was measured at a plurality of points, 170
The distribution was ± 30 nm. Then, in the same manner as in Example 2, 1 nm of LiF and 100% of Al were formed on the CN-PPV film.
The second electrode 10 was formed by vapor deposition to obtain an electroluminescent device.

The emission luminance and half-life of the fabricated light-emitting device were measured in the same manner as in Example 2.
At a driving voltage of V, red light emission with a maximum luminance of 40 cd / m ² was observed. In the light-emitting element, the dark spot grew quickly, and the half-life was about 1 hour.

Example 4 FIG. 4 shows a schematic plan view of an organic electroluminescent display of Example 4. This organic electroluminescent display is 50 mm
1600 mm thick IT on a 50 mm glass transparent substrate
The O transparent electrode (anode 7) is patterned so as to form a pixel of (160 × 3) × 120 dots, and the I
After a photoresist material is applied to the TO transparent electrode and one surface on the glass transparent substrate, the photoresist on the ITO electrode is removed by photolithography to form a film having a thickness of 1000.
The insulating layer 13 of nm was formed. I formed this insulating layer
After irradiating the TO substrate with ultraviolet rays in the same manner as in Example 1, an 80 ° -thick polyethylene dioxythiophene / polyethylene sulfonic acid (PEDO) was formed by spin coating.
(T / PSS, lower formula) layer (hole injection transport layer) was obtained. A 70 ° -thick cyanopolyphenylenevinylene (CN-PPV) layer (light-emitting layer) was obtained thereon by spin coating. All the organic layers were formed under a nitrogen atmosphere. 40 nm of Ca, Ag in the direction orthogonal to the ITO electrode on the organic layer
Is deposited to a thickness of 150 nm, and an electrode (cathode 1) having a width of 200 nm is formed.
120) were formed to obtain an organic electroluminescent display. The conditions of the vapor deposition were as follows.
× 10 ⁻⁶ Torr, substrate temperature: room temperature, deposition rate: Ca
2-3 ° / sec and Ag 4-5 ° / sec. Finally, a glass plate was adhered to the element with an adhesive under a nitrogen atmosphere so as to cover the entire display portion with an adhesive, followed by sealing. Under room temperature conditions, the initial luminance is 200 cd / m ² (1
3 V), and the half-life of the emission luminance (time required for the luminance to reach 100 cd / m ² ) was measured to be 120 hours. During driving, a good display was obtained with no peeling of the electrodes and no defect of the display section pixels. In FIG. 4, 12 is a display unit, 14 is an opening (organic layer),
Reference numeral 15 denotes an auxiliary electrode.

[0062]

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[0063]

According to the method for manufacturing a light emitting device of the present invention,
By irradiating the first electrode formed on the substrate with the energy beam, the surface of the electrode can be modified, that is, the wet-spreading property of the liquid containing the organic layer forming compound can be improved, and the adhesion to the substrate is strong and uniform. A light-emitting element having an organic layer and excellent durability can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view showing energy beam irradiation and an organic layer forming process in a method for producing an organic electroluminescent device of the present invention.

FIG. 2 is a schematic sectional view of an organic electroluminescent device of the present invention (Example 2 and Comparative Example 1).

FIG. 3 is a schematic sectional view of an organic electroluminescent device of the present invention (Example 3 and Comparative Example 2).

FIG. 4 is a schematic plan view of an organic electroluminescent display according to the present invention (Example 4).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass substrate 2 ITO film 3 Ultraviolet light 4 Liquid containing organic layer forming compound 5, 11 Organic layer 6 Substrate 7 Anode (first electrode) 8 Hole injection / transport layer 9 Light emitting layer 10 Cathode (second electrode) 12 Display unit 13 Insulation Layer 14 Opening (organic layer) 15 Auxiliary electrode

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H05B 33/28 H05B 33/28 F term (reference) 3K007 AB04 AB11 AB15 BA06 CA01 CB01 DA01 DB03 EB00 FA01 4J002 CA00W CN00X GP03 GQ02 GQ03 HA01

Claims (10)

[Claims] Forming a first electrode on a substrate;
An organic layer-forming compound-containing liquid is applied and dried on an electrode to form an organic layer having a single-layer or multilayer structure, and a second electrode is formed on this organic layer to produce an organic electroluminescent device. A method for manufacturing an organic electroluminescent device, comprising irradiating an energy beam on a first electrode before forming a layer. 2. An energy beam having a wavelength of 350 to 150 n.
The method for producing an organic electroluminescent device according to claim 1, wherein the ultraviolet light is m ultraviolet rays. 3. The method according to claim 1, wherein the first electrode is made of indium tin oxide. 4. The organic layer-forming compound-containing liquid comprises a conjugated polymer organic compound or a precursor thereof.
4. The method for producing an organic electroluminescent device according to any one of items 1 to 3. 5. The method according to claim 4, wherein the conjugated polymer organic compound is polyarylene vinylene. 6. The method according to claim 5, wherein the polyarylene vinylene is a poly-p-phenylene vinylene derivative. 7. The method for producing an organic electroluminescent device according to claim 1, wherein the liquid containing the organic layer forming compound contains an organic conductive resin. 8. The method according to claim 7, wherein the organic conductive resin contains polyethylene dioxythiophene. 9. The method for producing an organic electroluminescent device according to claim 1, wherein the liquid containing the organic layer forming compound is a liquid in which the organic layer forming compound is dissolved or dispersed in a solvent. 10. The method according to claim 7, wherein the solvent is a solvent containing at least one of water, an alcohol-based solvent, and a glycol-based solvent.