JPH0337992A - Manufacture of organic electroluminescence element - Google Patents

Abstract

PURPOSE:To enable the efficient manufacture of an organic electroluminnescent element of a large luminous amount and area, and long lifetime with relatively simple operation by forming a luminous layer on the electrode of anode or cathode via a process with power supply in the condition where the film of a luminous layer material is formed. CONSTITUTION:A luminous layer material is dispersed or solubilized in a water soluble media with an interfacial active agent of 10 to 20 HLB. In addition, a luminous layer is formed on the electrode of anode or cathode via the processing of the dispersed or solubilized solution with power supply in the condition where the layer of the luminous layer is generated. According to the aforesaid construction, operation such as alignment is not required in laminating functional thin films on the electrode, and a desired thin film can be efficiently manufactured with relatively simple operation. Also, the obtained organic EL element has a wide contact area and high brightness and efficiency.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing an organic electroluminescent device, and more specifically, an organic electroluminescent device that emits a large amount of light, has a fast response speed, and is useful as a variety of display materials. This invention relates to an efficient manufacturing method.

[Prior art and problems to be solved by the invention] Electroluminescent elements (hereinafter referred to as EL elements) have the characteristics of high visibility due to self-luminescence, and excellent impact resistance because they are completely solid-state elements. Currently, various EL elements using inorganic or organic compounds in the light emitting layer have been proposed, and attempts are being made to put them into practical use. Of these, organic thin film E
Since the L element can significantly reduce the applied voltage, various materials are being developed.

This organic thin film EL device includes an organic EL device consisting of an anode/a light emitting layer/a cathode, an anode/a hole injection transport layer/a light emitting layer/
An organic EL device consisting of a cathode, an organic EL device consisting of an anode/emitting layer/electron injecting/transporting layer/cathode, or an organic EL device consisting of anode/hole injecting/transporting layer/emitting layer/electron injecting/transporting layer/cathode, etc. Various types of laminated light emitting layers and thin layers having various functions have been developed.

Conventionally, various lamination methods such as vapor deposition, ion beam, plasma polymerization, LB, etc. are known as methods for manufacturing such organic EL elements. However, these methods have the disadvantage that the steps are complicated and productivity is poor. Furthermore, organic EL devices obtained by these methods have problems such as a small amount of light emission and a small light emitting area.

[Means to accomplish the task]

Therefore, the present inventors have conducted extensive research in order to develop a method for efficiently manufacturing an organic EL element that has a large amount of light emission, a large light emitting area, and a long life span with relatively simple operations.

As a result, a dispersion or solubilization of the material of the light-emitting layer or other functional layer in an aqueous medium using HLB (10 to 20 surfactants) was applied on the electrode under specific conditions. It has been found that the above-mentioned problems can be achieved by forming a light-emitting layer and the like using a method of conducting an electric treatment using a so-called micelle electrolysis method.

The present invention was completed based on this knowledge. That is, the present invention is an organic EL device consisting of an anode/emitting layer/cathode.
In manufacturing the device, a dispersion or solubilization solution obtained by dispersing or solubilizing the luminescent layer material in an aqueous medium with a surfactant having an HLB value of 10 to 20 is applied onto the anode or cathode electrode. An organic E, characterized in that a light emitting layer is formed by conducting a current treatment under conditions that produce a film of the light emitting layer material.
A method for manufacturing an L element is provided. Further, the present invention also provides an electrode comprising an anode/a hole injection/transport layer/a light emitting layer/a cathode.
L element, an organic EL element consisting of an anode/emissive layer/electron injection/transport N/cathode or anode/hole injection/transport layer/emissive layer/
In manufacturing an organic EL device consisting of an electron injection transport layer/cathode, at least one of the hole injection transport layer material 3, the light emitting layer material, and the electron injection transport layer material is prepared in a dispersion or solubilized solution in the same manner as above. The present invention also provides a method for manufacturing an organic EL element by subjecting the organic EL element to a current treatment to form a desired functional layer.

The present invention thus provides (1) an organic EL device consisting of an anode/a light-emitting layer/a cathode, (2) an anode/a hole injection/transport layer/a light-emitting layer/
An organic EL device consisting of a cathode, (3) an organic EL device consisting of an anode/emissive layer/electron injecting/transporting layer/cathode, and (4) an organic EL device consisting of an anode/hole injecting/transporting layer/emissive layer/electron injecting/transporting layer/cathode. This is a method that utilizes the so-called cell electrolysis method in manufacturing EL elements. Here, in the method of the present invention, at least one of the layers constituting the EL element is laminated by a cell electrolysis method, and other layers not formed by the cell electrolysis method are laminated by other lamination methods, e.g. masking vapor deposition method,
The ion beam method, plasma method, sputtering method, etching method, casting method, dip method, LB method, etc. can be used in combination.

The material for the light emitting layer of the organic EL element used in the present invention is not particularly limited as long as it has a light emitting function, and can be arbitrarily selected from conventionally known compounds. For example, polycyclic condensed aromatic compounds, fluorescent brighteners such as benzothiazole type, pencil dazole type, and pensoxazole type, metal chelated oxinoid compounds, distyrylbenzene type compounds, etc. can be used.

Examples of the polycyclic fused aromatic compound include anthracene, anthraquinone, naphthalene, and phenanthrene. Examples include fused ring luminescent substances containing pyrene, chrysene, and perylene skeletons, and other fused ring luminescent substances containing about 8 fused rings. In addition, the fluorescent whitening agents in each prefecture are as follows:
For example, those described in JP-A-59-194393 can be used, and a representative example thereof is 2,5-bis(5,7-di-t-pentyl-2-benzoxasilyl)-1,3 ,4-thiadiazole; 4,4”-bis(5
,7-t-pentyl-2-benzoxasilyl)stilbene; 4,4°-bis[5,7-di(2-methyl-2
-butyl)-2-benzoxasilyl]stilbene; 2
,5-bis(5゜7-di-t-pentyl-2-benzoxasilyl)thiophene; 2,5-bis[5-(α,α
-dimethylbenzyl)-2-benzoxasilylcothiophene: 2,5-bis[5,7-di(2-methyl-2
-butyl)-2-benzoxazole]-3,4-diphenylthiophene; 2,5-bis(5-methyl-2-benzoxasilyl)thiophene; 4,4''-bis-(2
-Benzoxacylyl)biphenyl; 5-methyl-2-
(2-(4-(5-methyl-2-benzoxasilyl)
2-(2-(
Benzoxazole series such as [4-chlorophenyl)vinyl]nut(1,2-d)oxazole, 2.2"-(
Benzothiazole series such as p-phenylene divinylene)-bisbenzothiazole; Examples include fluorescent brighteners such as benzimidazole-based brighteners such as benzigodazole.

Further, the metal chelated oxanoid compound includes:
For example, those described in JP-A-63-295695 can be used. A typical example is tris (8-
quinolinol)aluminum, bis(8-quinolinol)magnesium, bis(benzo(f)-8-quinolinol)zinc, bis(2-methyl-8-quinolinolado)aldanium oxide, tris(8-quinolinol)indium 1 tris( 5-methyl-8-quinolinol) aluminum, 8-quinolinol lithium, tris(5-
chloro-8-quinolinol) gallium.

bis(5-chloro-8-quinolinol)calcium,
Examples include 8-hydroxyquinoline metal complexes such as HolJC zinc([)-bis(8-hydroxy-5-quinolinonyl)methaneco, dilithium evindridione, and the like.

Further, as the distyrylbenzene compound, for example, those described in Japanese Patent Application No. 1-29681 can be used. There are various 1°4-bis(alkylstyryl)benzene derivatives described in the specification, but
For example, the following can be given:

The light-emitting layer in the organic EL device of the present invention may be appropriately selected from the above-mentioned materials, but two or more types can also be used in combination.

Furthermore, only one light-emitting layer may be present between the electrodes, or light-emitting layers made of different materials may be laminated. Furthermore, depending on the intended device, it is also effective to interpose a hole injection transport layer and/or an electron injection transport layer between the electrode and the light emitting layer. Also, 1 each! The functional layer may consist of one layer or a plurality of layers.

In this way, by forming a laminated structure of each functional layer, the luminescence intensity can be significantly improved compared to a single-layer structure having only a light-emitting layer.

The organic EL device of the present invention includes (1) anode/light emitting layer/
Cathode, (2) Anode/Hole injection transport layer/Light emitting layer/Cathode, (
3) Anode/hole injection transport layer/light emitting layer/electron injection transport layer/
Examples include cathode or (4) anode/luminous layer/electron injection/transport N/cathode laminated in this order.

By sandwiching the hole injection transport layer between the anode and the light emitting layer, many holes are injected into the light emitting layer with a lower electric field. The material for the hole injection and transport layer to be laminated can be used without any particular limitation as long as it is a hole transport compound that forms a layer having the function of transmitting holes injected from the anode to the light emitting layer.

Preferred hole transport compounds herein have hole mobilities of at least 10-'afl/volt-second when the layer is placed between electrodes subjected to an electric field of 104-106 volts/cva. Therefore, preferred examples include various compounds used as hole charge transport materials in photoconductive materials.

Examples of such charge transport materials include the following.

■Triazole derivatives described in U.S. Patent No. 3112197, etc.; ■Oxadiazole derivatives described in U.S. Patent No. 3189447, etc.; ■Triazole derivatives described in U.S. Patent No. 37-16096, etc. Imidazole derivatives, ■U.S. Patent No. 3615402, U.S. Patent No. 3820989,
3542544, Japanese Patent Publication No. 45-555, Japanese Patent Publication No. 51-10983, and Japanese Patent Publication No. 51-9322.
No. 4, No. 55-17105.

No. 56-4148, No. 55-108667, No. 1 No. 55
Boaryl alkane derivatives described in U.S. Pat.
No. 49-105537, No. 55-51086,
No. 56-80051, No. 56-88141, No. 57
-45545, 54-112637, 55-7
Pyrazoline derivatives and pyrazolone derivatives described in Japanese Patent Publication No. 4546, ■U.S. Pat.
No. 0105, No. 46-3712, No. 47-25336
Publication No. 54-53435, JP-A No. 54-1
10536, US Pat. No. 54-119925, etc.; ■ US Pat. No. 3,567,450, US Pat.
No. 3240597, No. 3658520.

No. 4232103, No. 4175961, No. 4012
Specification No. 376, Japanese Patent Publication No. 49-35702, No. 39-
No. 27577, as well as Japanese Patent Application Laid-open Nos. 55-144250 and 56-119132.

56-22437, West German Patent No. 11105, etc.; ■Amino-substituted chalcone derivatives described in U.S. Pat. No. 3,526,501, etc.; ■U.S. Pat. No. 3,257,203. [Phase]Styrylanthracene derivatives described in JP-A No. 56-46234, etc.; ■Fluorenone derivatives described in JP-A-54-110837, etc.; U.S. Patent No. 3,717,462 and JP-A-54-54
No. 9143, No. 55-52063, No. 55-5206
No. 4, No. 55-46760, No. 55-85495,
Hydrazone derivatives described in JP-A No. 57-11350, JP-A No. 57-148749, etc., ■JP-A No. 61-210363, JP-A No. 61-22845L
No. 61-14642, No. 61-72255, No. 62-47646, No. 62-36674, No. 62-
No. 10652, No. 62-30255, No. 60-934
No. 45, No. 60-94462, No. 60-174749
Examples include stilbene derivatives described in No. 60-175052 and the like.

A particularly preferable example is JP-A-63-2956
A compound (aromatic tertiary amine) as a hole transport layer and a compound as a hole injection zone (
porphyrin compounds).

Particularly preferable examples of the hole transfer compound include JP-A No. 53-27033, JP-A No. 54-58445,
Publication No. 54-149634.

No. 54-64299, No. 55-79450, No. 55-144250, No. 56-119132
No. 61-295558, No. 61-983
This is disclosed in Japanese Patent No. 53, US Pat. No. 4,127,412, and the like. Examples of these are as follows.

Old Shishi 1013 The hole injection transport layer of the present invention may be composed of a single layer consisting of one or more of these compounds, or may be formed by laminating other hole injection transport layers comprising different kinds of compounds. It may be something.

On the other hand, in the present invention, by sandwiching the electron injection transport layer between the cathode and the light emitting layer, many electrons are injected into the light emitting layer with a lower electric field. The material for the electron injection and transport layer is an electron transfer compound, which has the function of converting electrons injected from the cathode into a light emitting layer. As such a material, any material can be used without particular limitation as long as it can form a thin film having the above-mentioned functions.

Specifically, the following can be mentioned.

Nitro-substituted fluorenone derivatives such as
No. 149259, No. 58-5545C, No. 63-10
Anthraquinodimethane derivatives described in Publication No. 4061 etc., ■Polymer Preprints, Japan
Vol, 31+ Na5 (1988), p, 6
Diphenylquinone derivatives such as those described in 81 etc., thiopyrane dioxide derivatives such as ■J, J, APPl, Phys, 27. L
269 (1988) etc., ■JP-A No. 60-69657, No. 61-14376,
Fleolenylidene methane derivatives described in JP-A No. 61-148159, etc.;
Examples thereof include anthraquinodimethane derivatives and anthrone derivatives, which are described in Japanese Patent Publication No.

■Japan Society for the Promotion of Science, 125th Committee on Photoelectric Interconversion, No. 12
In the method of the present invention, the above-mentioned materials are used in the electric cell electrolysis method, that is, these materials are treated in an aqueous medium. A dispersion or solubilization solution obtained by dispersing or solubilizing in the body with a surface active substance having an HLB value of 10 to 20 is prepared under conditions such that a film (thin film) of the material is formed on the electrode (anode or cathode). A thin film layer can be formed efficiently by carrying out a method of energization treatment.

Such organic EL elements are usually formed on a substrate. The substrate used in the organic EL device of the present invention is preferably transparent, and glass, transparent plastic, quartz, etc. are generally used.

Further, the following electrodes (anode, cathode) are preferable. As the anode, an electrode material having a large work function, that is, 4 eV or more, is preferably a metal 1 alloy, an electrically conductive compound, or a mixture thereof. Specific examples of such electrode materials include metals such as Au, Cur,
I.T.O.

Examples include conductive transparent materials such as SnO□ and ZnO, conductive polymers, and oxide conductors. The anode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering.

At this time, the electrode can be patterned by a known method, such as a method using a mask or an etching method using a resist.

When emitting light from this electrode, reduce the transmittance to 10%.
It is desirable to make it larger, and the sheet resistance as an electrode is preferably several hundred Ω/cd or less.

Furthermore, although the film thickness depends on the material, it is usually selected in the range of 10 to 200 nm.

On the other hand, as the cathode, it is preferable to use a metal 2 alloy having a small work function, that is, 4 eV or less, an electrically conductive compound, or a mixture thereof as an electrode material. Specific examples of such electrode materials include Na, Na alloy, Mg
, Li, Mg/Cu mixture, A l / A I O
Examples include z, I n, etc.

The cathode can be manufactured by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. Pattern processing can be performed using the well-known mask method and etching method as described above. In addition, the sheet resistance of the electrode is preferably several hundred Ω/d or less, and the film thickness is usually 10 nm to 1 μm, preferably 50 to 200 nm.
selected within the range of m. In the device of the present invention, it is preferable that either the anode or the cathode be transparent or semi-transparent, since this allows light to be transmitted and extracted efficiently.

In the method of the present invention, an electrode (anode or cathode) is first patterned and formed on the substrate as described above by the method described above, and then a desired thin layer, such as a light-emitting layer and a hole injection transport layer, is formed on the substrate. Alternatively, at least one electron injection transport layer is laminated by a so-called micelle electrolysis method, and further an electrode and a cathode are formed when the electrode on the substrate is an anode, and an anode is formed when the electrode on the substrate is a cathode.

In this lamination, the laminated materials, specifically, one or more materials of the above-mentioned light emitting layer, hole injection transport layer, or electron injection transport layer, are mixed in an aqueous medium with an HLB value of 10 to 20. Disperse or solubilize with a surfactant to obtain a dispersion or solubilized solution. Here, the aqueous medium includes various media such as water, a mixture of water and alcohol, and a mixture of water and acetone.

On the other hand, in the method of the present invention, a surfactant having an HLB value of 10 to 20, preferably 12 to 18 is used as the surfactant. Suitable examples of such surfactants include nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, polyoxyethylene alkylphenyl ether, and polyoxyethylene polyoxypropylene alkyl ether. be able to. In addition, it is also possible to use alkyl sulfates, polyoxyethylene alkyl ether sulfates, alkyltrimethylammonium chlorides, fatty acid diethylaminoethyladides, and the like.

Further, preferred examples of surfactants include the following ferrocene derivatives. That is, the general formula [wherein, R1
and R2 are each an alkyl group having 6 or less carbon atoms, an alkoxy group having 6 or less carbon atoms, an amino group, a dimethylami) group,
It represents a hydroxyl group, an acetyl group, a carboxyl group, a methoxycarbonyl group, an acetoxy group, an aldehyde group, or a halogen, R3 represents hydrogen or a linear or branched alkyl group or alkenyl group having 4 to 18 carbon atoms, and R4 and R5 represent Each represents hydrogen or methyl group. Y represents oxygen or oxycarbonyl group, a is an integer of 0 to 4,
b is an integer from O to 4; m is an integer from 1 to 18; n is from 2.0 to
Indicates a real number of 70.0. ] The ferrocene derivative represented by the following can be mentioned as a typical example. Here, each symbol in general formula (1) is as described above. In other words, International Publication WO38107
538, WO39101939゜Patent Application No. 63-2337
As described in No. 97 and others, R1 and R- each represent an alkyl group having 6 or less carbon atoms (methyl group (CH3),
Ethyl group (Ct Hs), etc.), alkoxy group (methoxy group (OCH3), ethoxy group (OCzHs), etc.), amino group (N) (Ri.

dimethylamino group (N(CHi)z)), hydroxyl group (O
H).

Acetylamino group (NHCOCH), carboxyl group (COOH), acetoxy group (OCOC) 13).

Methoxycarbonyl group (COOCR3), aldehyde group (CHO) or halogen (chlorine, bromine).

RI and Rz, which represent fluorine, iodine, etc., may be the same or different, and even if a plurality of R1 and Rt each exist in the five-membered ring of ferrocene, the plurality of substituents are the same. It may be different or different. Further, R3 represents hydrogen or a straight chain or branched alkyl group or alkenyl group having 4 to 18 carbon atoms.

Furthermore, Y is oxygen (-0-) or oxycarbonyl group (-
C-O-), R' and RS are hydrogen or 1 is a methyl group (CH3). Therefore, −0(CHIC
H, 0), lH.

-C-0(CH,CH,○)nH or 1 etc.

Moreover, m represents an integer of 1 to 18. Therefore, an alkylene group having 1 to 18 carbon atoms, such as an ethylene group or a propylene group, is interposed between the ring carbon atom and the oxygen or oxycarbonyl group. Furthermore, n indicates the repeating number of the oxyalkylene group such as the above-mentioned oxyethylene group, and means not only an integer from 2.0 to 70.0 but also a real number including these, and the average number of repeating groups such as the oxyalkylene group. It indicates the value.

There are various ferrocene derivatives used in the method of the present invention in addition to those represented by the above general formula (1),
Ammonium type, pyridine type (International Publication WO3
B107538 etc.), patent application No. 63-23379
Specification No. 7, Specification No. 63-233798, Specification No. 63-
248600, 63-248601, Japanese Patent Application No. 1-45370, 1-54956, 1-70680, 1-70681
Specification of No. 1-76498 and No. 1-76
Mention may be made of the ferrocene derivatives described in No. 499.

Among these, the following ferrocene derivatives are particularly preferably used.

The above-mentioned ferrocene derivatives can disperse or solubilize the desired functional layer material in an aqueous medium very efficiently.

In the method of the present invention, first, the above-mentioned surfactant and materials for the desired functional layer are placed in an aqueous medium and thoroughly stirred for about 1 hour to 7 days using an ultrasonic wave, a homogenizer, a stirrer, or the like. In this operation, the functional layer material is uniformly dispersed or solubilized in the aqueous medium by the action of the surfactant having an HLB value of 10 to 2o, and becomes a dispersion liquid or a ξ cell solution. Now, add a supporting salt as desired to the homogeneous dispersion or fruit cell solution obtained in this way, and remove excess functional layer material by centrifugation, decantation, static sedimentation, etc. depending on the situation. Then, the obtained electrolytic solution is subjected to energization treatment while being left standing or with slight stirring. In addition, the functional layer material may be added to the electrolytic solution during the energization process, or a part of the electrolytic solution may be extracted from the system, and the functional layer material is added to the extracted electrolytic solution and thoroughly mixed and stirred. A circulation circuit for later returning this liquid to the system may also be provided.

The concentration of the functional layer material at this time may be at least the saturation concentration, and the concentration of the surfactant is not particularly limited, but is usually 10 μM to 0.1 M, preferably 0.5 mM to 5 mM.
Select within the range. Further, a supporting salt (supporting electrolyte) is added as necessary to adjust the electrical conductivity of the aqueous medium. The amount of supporting salt added may be within a range that does not interfere with the solubilization or precipitation of the dispersed functional layer material, and is usually at a concentration of about 0 to 300 times that of the surfactant, preferably 10 to 200 times. As a guideline, the concentration should be approximately

Although it is also possible to conduct current application without adding this supporting salt, in this case a highly pure thin film containing no supporting salt can be obtained. In addition, when using a supporting salt, the type of supporting salt is particularly limited as long as it can adjust the electrical conductivity of the aqueous medium without hindering the progress of solubilization or precipitation of the hydrophobic substance on the electrode. There isn't.

Specifically, - Sulfates (salts of lithium, potassium, sodium, rubidium, aluminum, etc.) and acetates (lithium, potassium, sodium, rubidium, beryllium, magnesium, calcium, etc.) are widely used as supporting salts in boat fishing. , strontium, barium, aluminum, etc.).

Halide salts (salts of lithium, potassium, sodium, rubidium, calcium, magnesium, aluminum, etc.) and water-soluble oxide salts (salts of lithium, potassium, sodium, rubidium, calcium, magnesium, aluminum, etc.) are suitable.

The energization conditions in the method of the present invention include the electrodes used,
That is, the conditions may be set such that a thin film of the functional layer material is formed on the anode or cathode, on the hole injection transport layer, on the light emitting layer, or on the electron injection transport layer. Here, the energization conditions vary depending on the situation, but specifically, the liquid temperature is set at room temperature to 8.
The conditions for forming a thin film of the functional layer material on the anode or cathode vary depending on the situation, but specifically the liquid temperature is room temperature to 70°C, preferably 20 to 60°C.
The energization process is performed at a constant potential or constant current, with the energization time being 1 minute to 2 hours. In this constant potential energization process, the distance between the two electrodes is 0.5 to 10. OV, preferably set to a potential of 3.0 to 0.5 V, and in the constant current energization process, the current density is set to 1 u A/Cl.
11-100 mA/cd, preferably 100 uA
/c may be set in the range of 4 to 10 mA/d.

It is also effective to further perform post-treatments on the thin film obtained by the method of the present invention, such as electrical cleaning, solvent cleaning, and baking treatment at 150 to 350°C, if necessary.

An organic EL device can be obtained by forming another electrode on the hole injection transport layer 2 light emitting layer or electron injection transport layer thus obtained by a conventionally known method.

According to the method of the present invention, various organic EL devices can be manufactured. For example, (1) an organic EL element in which an electrode (anode or cathode) is formed on a substrate by various methods, a light-emitting layer is laminated thereon by the above-mentioned micelle electrolysis method, and a counter electrode is further formed; ) An electrode is formed on the substrate by various methods, a hole injection transport layer is laminated thereon by the above-mentioned micelle electrolysis method or another method, and a light emitting layer is further laminated by the micelle electrolysis method or another method. However, hole injection transport layer 1
(3) an organic EL element in which at least one of the light-emitting layers is formed by the micelle electrolysis method) and a cathode formed thereon; (3) an electrode is formed on the substrate by various methods; (However, at least one layer of the emissive layer and the electron injection transport layer is formed by the micelle electrolysis method), and then an electron injection transport layer is laminated by a micelle electrolysis method or another method. Organic EL element with electrodes formed, (4) electrodes are formed on the substrate by various methods, and a hole injection transport layer 1 and a light emitting layer are laminated in this order on top of the electrodes by the above-mentioned micelle electrolysis method or other methods. However, an electron injection transport layer is further laminated by a micelle electrolysis method or another method. An example is an organic EL element formed with a . Further, the order of lamination here is not always from the substrate side, but also from the counter electrode side, so that a desired organic EL element can be formed.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Example 1 A glass substrate (25 x 75 x 1.1 cabinet size) provided with an ITO transparent electrode with a film thickness of 120 nm.

(manufactured by HOYA Corporation) was used as a transparent support substrate, which was ultrasonically cleaned with isopropyl alcohol for 30 minutes, and further immersed in isopropyl alcohol for cleaning.

N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4°-diaminobiphenyl (TPO)2
Add 00g to 2mM FPEG aqueous solution and 10g with ultrasound.
After dispersing for a minute, the mixture was stirred with a stirrer for 3 days. After that, LiBr was added to make the concentration 100mM, the above substrate was immersed to serve as an anode, a platinum plate was provided as a counter electrode, and 3
Electrolyzed for 0 minutes. The amount of current applied was 0.03 coulombs (C).

In this way, a hole injection transport layer with a thickness of 1100 nm was formed. Furthermore, a molybdenum resistance boat containing Coumarin 30 was placed in a vacuum evaporation apparatus, and heated to 235°C with electricity applied to the hole injection transport layer at a evaporation rate of 0.5 to 0.7 nm/sec. A light emitting layer having a thickness of 1100 nm was provided by vapor deposition. Note that the temperature of the substrate during vapor deposition was room temperature.

After the vapor deposition, the vacuum chamber was opened, a stainless steel mask was placed on the light emitting layer, 3 g of magnesium was placed in a resistance heating boat made of molybdenum, and copper was placed in a crucible of an electron beam evaporator. After this, the vacuum chamber was heated again to 3 x 10-'Pa.
The pressure was reduced to 100.degree. C., and the boat containing magnesium was energized to deposit magnesium at a deposition rate of 4 to 5 nm/sec. At the same time, the copper is heated by an electron beam, and the evaporation rate is 0.
Copper was evaporated at a rate of 1 to 0.3 nm/sec, and copper was mixed with the magnesium to form a Mg:Cu counter electrode. Through the above steps, the production of the intended EL element was completed.

When a direct current of 15 V was applied using the ITO electrode of this device as the positive electrode and the counter electrode made of Mg:Cu as the negative electrode, a current with a current density of 32 mA/c4 flowed and green light was emitted.

The maximum emission wavelength at this time is 508 nm, and the emission brightness is 500 nm.
cd/rrf and luminous efficiency were 0.331 m/W.

Incidentally, Coumarin 30 is 3-(2'-N-methylbenzigodazolyl)-7-N,N-diethylaminocoumarin and has the following structure.

tHs H3 Example 2 TPD was formed into a film on an IT0 transparent electrode similar to the ITO transparent electrode used in Example 1 in the same manner as in Example 1.
/ITO electrode was obtained. The film thickness was 95 nm.

Coumarin 30 (200 mg and 2 mM) was added to the FPEGPE method, dispersed with ultrasound for 10 minutes, and then stirred with a stirrer for 3 hours. Thereafter, LiBr was added to give a concentration of 100 mM, the above TPD/ITO electrode was immersed to serve as an anode, platinum was provided as a counter electrode, and electrolysis was carried out at 0.5 μm for 30 minutes. The amount of current applied was 0.03G. As a result, Coumarin 30/J
PD/ITO was obtained.

After the vapor deposition, the vacuum chamber was opened, a stainless steel mask was placed on the light emitting layer, 3 g of magnesium was placed in a resistance heating boat made of molybdenum, and copper was placed in a crucible of an electron beam evaporator. After this, the vacuum chamber was heated again to 3 x 10-'Pa.
The pressure was reduced to 100.degree. C., and the boat containing magnesium was energized to deposit magnesium at a deposition rate of 4 to 5 nm/sec. At the same time, the copper is heated by an electron beam, and the evaporation rate is 0.
Copper was evaporated at a rate of 1 to 0.3 nm/see, and copper was mixed with the magnesium to form a Mg:Cu counter electrode. Through the above steps, the production of the intended EL element was completed.

When a direct current of 15 V was applied using the ITO electrode of this device as the positive electrode and the counter electrode made of Mg:Cu as the negative electrode, a current with a current density of 21 mA/c+fi flowed and green light was emitted. The maximum emission wavelength at this time was 510 nm, and the emission brightness was 8
The luminous efficiency was 1.46 fm/W.

Example 3 200 μM of tetraphenylbutadiene (TPB)
In addition to the FPEGPE method described above, the material was dispersed with ultrasonic waves for 10 minutes, and then stirred with a stirrer for 3 days.

Thereafter, LiBr was added to give a concentration of 100 mM, the ITO substrate used in Example 1 was immersed to serve as an anode, platinum was provided as a counter electrode, and electrolysis was performed at 0.5 V for 300 minutes.

The amount of current applied was 0.3C. As a result, TPB/IT
I got an O.

Next, the vacuum chamber was opened, a stainless steel mask was placed on top of the luminescent layer, and Al was placed in an electron beam-heated evaporation crucible, and the pressure of the vacuum chamber was reduced to 3 × 10-'Pa again. Later, with an electron beam, AI! , by heating 1~
The intended EL device was fabricated by depositing 1 at a deposition rate of 1.5 nm/sec to form a counter electrode made of Al with a thickness of 150 nm.

When a direct current of 40 V was applied using the ITO electrode of this device as the positive electrode and the counter electrode made of Al2 as the negative electrode, a current with a current density of 37 mA/c111 flowed and blue light was emitted.

The maximum emission wavelength at this time is 420 nm, and the emission brightness is 1 cd.
/rd.

Example 4 A transparent electrode similar to the IT○ transparent electrode used in Example 1 was
The anode was immersed in a solution of IM pyrrole and 0.1 M LiBr, platinum was provided as a counter electrode, and electropolymerization was carried out at a potential of 1.5 μ for 3 minutes to obtain a pyrrole/ITO electrode. The current flowing at this time was 35 μA/cflt.

Next, a solution of 100 μm of perylene and 2 mM FPEG was dispersed by ultrasonic waves for 10 minutes, and then stirred with a stirrer for 3 days. Then, add LiBr to a concentration of 100mM,
The above pyrrole/■To electrode is immersed in this to serve as an anode,
Platinum was provided as a counter electrode, and electrolysis was performed at 0.5V for 30 minutes. The amount of current applied was 0.03C. As a result, perylene/polypyrrole/ITo was obtained.

After the vapor deposition, the vacuum chamber was opened, a stainless steel mask was placed on the light emitting layer, 3 g of magnesium was placed in a resistance heating boat made of molybdenum, and copper was placed in a crucible of an electron beam evaporator. After this, the vacuum chamber was heated again to 3 x 10-'Pa.
The pressure was reduced to 100.degree. C., and the boat containing magnesium was energized to deposit magnesium at a deposition rate of 4 to 5 nm/sec. At the same time, the copper is heated by an electron beam, and the evaporation rate is 0.
Copper was evaporated at a rate of 1 to 0.3 nm/sec, and copper was mixed with the magnesium to form a Mg:Cu counter electrode. Through the above steps, the production of the intended EL element was completed.

When a direct current of 13 V was applied using the ITO electrode of this device as the positive electrode and the counter electrode made of Mg:Cu as the negative electrode, a current with a current density of 46 mA/cnl flowed, and greenish-yellow light emission was obtained. The maximum emission wavelength at this time was 560 nm, the emission brightness was 240 cd/n (and the emission efficiency was 0.131 m/W).

Comparative Example I Glass substrate with ITO (25mm x 75mm x
1. 1 nm size, manufactured by HOYA Corporation) was used as a transparent support substrate, and this was ultrasonically cleaned with isopropyl alcohol for 30 minutes, and then this transparent substrate, which had been immersed in isopropyl alcohol and cleaned, was dried with dry nitrogen gas and used as a substrate for vacuum evaporation equipment. Fix it in a holder and add 200 g of N,N'-diphenyl-N,N''-bis(3-methylphenyl)-1,1'-biphenyl-4,4''-cyamine (TPD) to a resistance heating boat made of molybdenum. Then, 200 μm of Coumarin 30 was placed in another resistance heating boat made of molybdenum and attached to a vacuum evaporation device.

Thereafter, the pressure in the vacuum chamber was reduced to 2 × 10-'Pa, and T
The boat containing the PD was heated to 220°C by applying electricity, and was deposited on a transparent support substrate at a deposition rate of 0.1 to 0.3 nm/sec to form a hole injection layer (hole injection transport) with a thickness of 100 nm. layer). Furthermore, the boat containing Coumarin 30 was energized and heated to 235°C at a deposition rate of 0.5 to 0.7n.
The film was deposited on the hole injection layer on the transparent support substrate at a rate of m/sec to obtain a light emitting layer with a thickness of 1100 nm. At this time, the temperature of the substrate was room temperature.

After vapor deposition, the vacuum chamber was opened, a stainless steel mask was placed on the light emitting layer, 3 g of magnesium was placed in a resistance heating boat made of molybdenum, and copper was placed in a crucible of an electron beam evaporator. After that, open the vacuum chamber again to 3 x 10-'Pa.
The pressure was reduced to 100%, and electricity was applied to the board containing magnesium to deposit magnesium at a deposition rate of 4 to 5 nm for 7 seconds. At this time, the copper is heated by an electron beam at the same time, and the
Copper was evaporated at a rate of 0.3 nm/sec, copper was mixed with the magnesium, and the EL element was fabricated using 0 or more as a counter electrode.

When 20 V DC was applied to this device using the ITO electrode as the anode and the counter electrode made of a mixture of magnesium and copper as the negative electrode, a current with a current density of 87 mA/c++1 flowed.
A green luminescence was obtained.

At this time, the maximum emission wavelength was 510 nm, the half width of the light emitter was 60 nm, and the emission brightness was 440 cd/bo.

〔Effect of the invention〕

As described above, according to the method of the present invention, when laminating a functional thin film on an electrode, a desired thin film can be efficiently manufactured with relatively simple operations without requiring operations such as alignment. . Moreover, the obtained organic EL device has a large contact area, high brightness, and high efficiency.

Therefore, the method of the present invention can be effectively used for manufacturing organic EL elements used in display materials, printers, liquid crystal backlights, and the like.

Claims (5)

[Claims] (1) When producing an organic electroluminescent device consisting of an anode/emissive layer/cathode, a dispersion or 1. A method for manufacturing an organic electroluminescent device, which comprises forming a light-emitting layer by applying electricity to a solubilized solution under conditions such that a film of the light-emitting layer material is formed on an anode or a cathode. (2) In manufacturing an organic electroluminescent device consisting of an anode/hole injection/transport layer/light emitting layer/cathode,
A dispersion or solubilized solution obtained by dispersing or solubilizing the hole injection transport layer material and/or the light emitting layer material in an aqueous medium with a surfactant having an HLB value of 10 to 20 is applied to the anode or cathode electrode. A method for manufacturing an organic electroluminescent device, which comprises forming a hole injection transport layer and/or a light emitting layer by applying current under conditions that produce a film of the material. (3) In manufacturing an organic electroluminescent device consisting of an anode/emitting layer/electron injection/transport layer/cathode,
A dispersion or solubilization solution obtained by dispersing or solubilizing the light emitting layer material and/or the electron injection transport layer material in an aqueous medium with a surfactant having an HLB value of 10 to 20 is applied onto the anode or cathode electrode. A method for manufacturing an organic electroluminescent device, characterized in that a light emitting layer and/or an electron injection transport layer is formed by applying electricity under conditions that produce a film of the material. (4) In manufacturing an organic electroluminescent device consisting of an anode/hole injection/transport layer/emissive layer/electron injection/transport layer/cathode, at least one layer of hole injection/transport layer material, emissive layer material, and electron injection/transport layer material is used. A film of the material is formed on the anode or cathode electrode by dispersing or solubilizing the material in an aqueous medium with a surfactant having an HLB value of 10 to 20. 1. A method for manufacturing an organic electroluminescent device, which comprises forming at least one of a hole injection transport layer, a light emitting layer, and an electron injection transport layer by applying current under certain conditions. (5) Claims 1 to 3, wherein the surfactant is a ferrocene derivative.
4. The manufacturing method according to any one of 4.