JP2006244943A - Organic el element and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL element in which a drying agent is not required and its manufacturing method. <P>SOLUTION: The organic EL element 10 comprises a substrate 12, an anode electrode 14 formed on the substrate 12, an organic layer 16 laminated on the anode electrode 14, a cathode electrode 18 laminated on the organic layer 16, an insulating film 20 which is formed so as to cover the anode electrode 14, the organic layer 16, and the cathode electrode 18 laminated and has at least an oxynitride film, and a film 22 of an organic/inorganic hybrid material formed so as to cover the insulating film 20. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an organic EL (Electroluminescence) element which is a thin flat light emitting element and a method for manufacturing the same.

  The organic EL element is advantageous in various aspects such as high brightness and thinness as compared with the liquid crystal display of the same flat display (Non-Patent Document 1).

  A bottom emission type organic EL element will be described. As shown in FIG. 5, the organic EL element 30 is formed on the substrate 12, the anode electrode 14 formed on the substrate 12, the organic layer 16 formed on the anode electrode 14, and the organic layer 16. And a sealing cap 32 for sealing the organic layer 16 and the like.

  The substrate 12 is made of transparent glass or plastic in order to transmit light. The anode electrode 14 is formed of a transparent conductive film such as ITO (indium tin oxide) in order to transmit light. It is preferable that the organic layer 16 has a multilayer structure such as a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, and an electron injection layer to increase luminous efficiency. The cathode electrode 18 is made of a metal such as aluminum. The sealing cap 32 is formed of metal or glass.

  By connecting the substrate 12 and the sealing cap 32 with the adhesive 34 in an inert gas atmosphere, the organic layer 16 can be shielded from the external atmosphere. The adhesive 34 is cured by UV irradiation.

  However, the gas generated when the adhesive 34 is cured may adversely affect the organic layer 16. Further, since the adhesive 34 is a polymer, oxygen and moisture enter from the outside through the adhesive 34 little by little, and the organic layer 16 is deteriorated. Therefore, it is necessary to attach a desiccant to the sealing cap 32. This becomes a problem of the reliability of the organic EL element 30 and increases the cost.

  Patent Document 1 discloses an organic EL display panel in which a partition is provided so as to surround an organic layer, a region surrounded by the partition is sealed with a resin, and a coating is provided so as to cover the whole. The organic layer can be protected from oxygen and moisture by resin sealing. However, the interface may crack due to the difference in thermal expansion between the resin and the organic layer, and the organic layer may come into contact with oxygen or moisture.

JP 2003-323974 A (see FIG. 1) By Koji Shinji “All about Organic EL” published by Nihon Jitsugyo Shuppan Publishing, p12-28 February 20, 2003

  The objective of this invention is providing the organic EL element which does not need to provide a desiccant, and its manufacturing method.

  The organic EL device of the present invention includes a substrate, an anode electrode formed on the substrate, an organic layer stacked on the anode electrode, a cathode electrode stacked on the organic layer, and the stacked layers An organic film formed so as to cover the anode electrode, the organic layer, and the cathode electrode, covering at least a nitride film, and covering the insulating film, and forming a three-dimensional bridge by a sol-gel reaction by a hydrolysis reaction of a metal alkoxide composition / Inorganic hybrid material film.

  The insulating film includes an oxide film in addition to the nitride film.

  The nitride film and the oxide film are overlaid.

  The organic EL device manufacturing method of the present invention includes a step of preparing a substrate, a step of forming an anode electrode on the substrate, a step of forming an organic layer on the anode electrode, and a cathode electrode on the organic layer. Forming an insulating film having at least a nitride film so as to cover the anode electrode, the organic layer, and the cathode electrode, and diluting the metal alkoxide composition in a solvent to prepare a liquid prepared in a solution. Applying on the insulating film; forming the applied liquid into a film; and curing the liquid into a film.

  The step of curing includes a dehydration condensation reaction by a hydrolysis reaction performed in an atmosphere of 80 ° C. or lower.

  The step of applying, the step of forming the liquid into a film, and the step of curing the liquid are performed in an inert gas atmosphere.

  The insulating film has an oxide film, and the step of forming the insulating film forms the nitride film and the oxide film alternately.

  According to the present invention, a film of an organic / inorganic hybrid material having a high barrier property can be formed in a relatively low temperature atmosphere of 80 ° C. or lower, and the organic layer can be protected. When the film of the organic / inorganic hybrid material directly touches the organic layer, the OH of the metal oxide glass film touches the organic layer and deteriorates. Therefore, the organic layer is also protected by the nitride film. Since a desiccant is not required as compared with conventional organic EL elements, this is a factor that can extend the life of the organic EL elements.

  The organic EL element and the manufacturing method thereof according to the present invention will be described with reference to the drawings. A bottom emission type organic EL element will be described. For convenience of explanation, the specification and drawings use one pixel of an organic EL element, but the present invention includes one in which pixels are arranged vertically and horizontally on a substrate.

  As shown in FIG. 1, the organic EL device 10 of the present invention includes a substrate 12, an anode electrode 14 formed on the substrate 12, an organic layer 16 stacked on the anode electrode 14, and an organic layer 16. The cathode electrode 18 laminated on the substrate, the anode electrode 14, the organic layer 16, and the cathode electrode 18 laminated are formed so as to cover the insulating film 20 having at least a nitride film, and so as to cover the insulating film 20. And a room temperature curable organic / inorganic hybrid material film 22.

  The substrate 12 is a transparent glass or plastic substrate. Light emitted from the organic layer 16 is emitted from the substrate side.

  The anode electrode 14 is formed of a transparent conductive film such as ITO. This is for transmitting light emitted from the organic layer 16.

  It is preferable that the organic layer 16 has a multilayer structure such as a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, and an electron injection layer to increase luminous efficiency.

  The cathode electrode 18 is formed of a metal such as Al, but may be a transparent conductive film such as ITO.

  As shown in FIG. 2, the insulating film 20 includes an oxide film 20b in addition to the nitride film 20a. The nitride film 20a has an effect of preventing intrusion of oxygen and moisture, but is fragile. Therefore, the strength of the insulating film 20 including the oxide film 20b is increased. The nitride film 20a is silicon nitride, silicon nitride oxide, or the like, and the oxide film 20b is silicon oxide or the like.

  The nitride film 20a and the oxide film 20b are overlapped. The insulating film 20 is made thick by overlapping several layers. For example, the thickness of the insulating film 20 is about 0.01 to 0.5 μm.

  The organic / inorganic hybrid material film 22 is a light-transmitting film in which three-dimensional cross-linking is formed by a sol-gel reaction by a hydrolysis reaction of a metal alkoxide composition. The organic / inorganic hybrid material film 22 has high shielding properties and is suitable for sealing the organic layer 16. The organic / inorganic hybrid material film 22 is mainly composed of glass as in the case of the conventional sealing cap 32. Since the nitride film 20a is thin, there may be a problem in shielding properties. However, the problem is solved by the film 22 of the organic / inorganic hybrid material. For example, the film thickness of the organic / inorganic hybrid material film 22 is about 1 to 20 μm. Further, since the insulating film 20 includes the nitride film 22a, the OH of the organic / inorganic hybrid material film 22 is prevented from reaching the organic layer 16 during manufacturing.

  As described above, the organic EL element 10 of the present invention does not need to be provided with a desiccant as in the prior art. The organic layer 16 is shielded by a film 22 of an organic / inorganic hybrid material. The fact that the desiccant may not be provided is a factor that extends the life of the organic EL element 10. Further, it is not necessary to prepare the sealing cap 32 having the depression as shown in FIG. 5, which leads to cost reduction of the organic EL element 10.

  The manufacturing method of the organic EL element 10 includes (1) preparing a substrate 12 (FIG. 3A). (2) The anode electrode 14 is formed on the substrate 12 (FIG. 3B). (3) The organic layer 16 is formed on the anode electrode 14 (FIG. 3C). (4) A cathode electrode 18 is formed on the organic layer 16 (FIG. 3D). (5) An insulating film 20 having at least a nitride film is formed so as to cover the anode electrode 14, the organic layer 16, and the cathode electrode 18 (FIG. 4A). (6) An organic / inorganic hybrid material film 22 is formed so as to cover the insulating film 20. The organic EL element 10 of FIG. 1 can be manufactured by the above process.

  The preparation of the substrate 12 in the above (1) includes cutting and cleaning a glass or plastic transparent substrate to a desired size.

  The formation of the anode electrode 14 in the above (2) is to form an ITO film and pattern it into a desired shape by etching or the like.

  The formation of the organic layer 16 in the above (3) is performed by vacuum deposition if the organic layer 16 is a low molecule. If the organic layer 16 is a polymer, an ink jet method or a spin coat method is used.

  The formation of the cathode electrode 18 in the above (4) is performed by depositing a metal such as Al by a vacuum deposition method.

The insulating film 20 of the above (5) is formed by CVD (chemiacl
Vapor deposition). Since the steps up to (4) are performed under vacuum, CVD can be performed as it is.

  The insulating film 20 has an oxide film, and the insulating film (5) is formed so that the nitride film and the oxide film overlap each other. That is, nitride films and oxide films are alternately formed by CVD.

  The organic / inorganic hybrid material film 22 of (6) is formed by applying a liquid 22a prepared as a solution by diluting the metal alkoxide composition in a solvent (see FIG. 4 ( b)). (Ii) The applied liquid 22a is formed into a film. (Iii) The film-like liquid is cured.

  The application of the above (i) is dropping by a spoid, brush coating, spray coating, roller coating or the like.

  The metal alkoxide composition preferably contains (a) an organic polysiloxane having a methyl group or a phenyl group, (b) an organic siloxane having a hydroxyl group or a hydrolyzable functional group, and (c) a curing agent.

  As said (a) organic polysiloxane which has a methyl group or a phenyl group, the liquid organic polysiloxane which has a methyl group or a phenyl group, and a C1-C4 alkoxy group is mentioned, for example. Examples of the alkoxy group having 1 to 4 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

  Examples of the hydrolyzable group in the organosiloxane having (b) hydroxyl group or hydrolyzable functional group include an alkoxy group, an acyloxy group, a ketoxime group, an amide group, an alkenyloxy group, and a halogen atom. . The component (b) organosiloxane may have a monovalent organic group or a hydrogen atom. Examples of the monovalent organic group include alkyl groups such as methyl, ethyl, propyl, butyl and hexyl; vinyl An alkenyl group such as phenyl, tolyl, xylyl; an aralkyl group such as phenethyl, β-phenylpropyl; an aminoalkyl group such as N- (β-aminoethyl) -γ-aminopropyl; Epoxy group-containing groups such as sidoxypropyl and 3,4-epoxycyclohexyl; (meth) acryl group-containing groups such as γ-methacryloxypropyl; mercaptoalkyl groups such as γ-mercaptopropyl; cyanoalkyl groups such as cyanoethyl; β A chloroalkyl group such as chloroethyl and γ-chloroethyl; a chloroalkyl group such as 3,3,3-trifluoropropyl; Examples include a uroalkyl group and the like. The component (b) may contain an alkoxy partial hydrolyzate (liquid silicone resin) as necessary.

  As the (c) curing agent, a curing catalyst used for a condensation curable silicone composition is usually used. Specific examples of the curing agent include organic amines such as triethanolamine; carboxylic acid metal salts such as tin octylate and zinc octylate; organotin compounds such as dibutyltin dilaurate and dibutyltin dioctoate; tetrabutyl titanate, tetrapropyl titanate Quaternary ammonium compounds such as quaternary ammonium carboxylates; amine-based silane cups such as γ-aminopropyltriethoxysilane and N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane A ring agent is mentioned. An organoaluminum compound or boron halide can also be used. Among these, an organic tin compound or a boron halide is preferable. Two or more of these curing agents can be used in combination.

  The solvent used for preparing the solution is not particularly limited as long as it dissolves and disperses the component (a), the component (b), and the component (c). For example, alcohols such as methanol, ethanol and isopropanol; ether alcohols and ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, tetrahydrofuran and dioxane; ketones such as acetone, methyl ethyl ketone and diethyl ketone; methyl acetate and ethyl acetate And esters such as n-butyl acetate; aliphatic hydrocarbons such as n-hexane, gasoline, rubber volatile oil, mineral spirit, and kerosene.

  By applying the metal alkoxide composition as described above to the substrate and performing a dehydration condensation reaction by a hydrolysis reaction of the metal alkoxide at a relatively low temperature, a light-transmitting film in which three-dimensional crosslinking is formed is formed.

  The method (ii) forming the liquid into a film includes forming the liquid applied with a spin coater into a film. A thin film is formed by spreading the applied liquid by a centrifugal force of rotation. Therefore, the amount of the liquid applied in the above (i) is set to be larger than the amount of the liquid formed into a film in consideration of the amount blown off. For example, the film thickness is about 1 to 20 μm.

  The curing (iii) includes a dehydration condensation reaction by a hydrolysis reaction performed in an atmosphere of 80 ° C. or less. This hydrolysis is carried out for about 0.1 to 1.0 hour. Since it is cured at a low temperature, the organic layer 16 is not deteriorated.

  The formation of the film 22 of the organic / inorganic hybrid material (6) is performed in an inert gas atmosphere. By performing in an inert atmosphere, deterioration of the organic layer 16 at the time of manufacture is prevented.

  As described above, according to the present invention, the organic / inorganic hybrid material film 22 can be formed at a relatively low temperature, and the organic layer 16 is not deteriorated. Since the metal oxide glass film 22 is formed after forming the nitride film at the time of manufacture, the OH of the organic / inorganic hybrid material film 22 does not touch the organic layer 16 and does not deteriorate the organic layer 16. In addition, since the film formation is performed at a relatively low temperature, the interface of each layer is hardly deteriorated.

  Since there is no need to bond the sealing cap and the substrate with an adhesive as in the prior art, there is no adverse effect on the organic layer 16 due to the adhesive shown in the prior art.

  The present invention is not limited to the above embodiment. For example, since the organic / inorganic hybrid material film 22 and the nitride film are transparent, the present invention may be applied to the organic EL element 10 having a top emission structure. In that case, the anode electrode 18 is formed of a transparent conductive film such as ITO. If necessary, the surface of the organic / inorganic hybrid material film 22 is flattened by a chemical / mechanical operation.

  In addition, the present invention can be carried out in a mode in which various improvements, modifications, and changes are added based on the knowledge of those skilled in the art without departing from the spirit of the present invention.

It is sectional drawing of the organic EL element of this invention. It is sectional drawing which shows the structure of an insulating film. It is sectional drawing which shows the manufacturing method of an organic EL element, (a) is a figure which prepares a board | substrate, (b) is the figure which formed the anode electrode on the board | substrate, (c) is organic on an anode electrode. It is the figure which formed the layer, (d) is the figure which formed the cathode electrode on the organic layer. It is sectional drawing which shows the manufacturing method of an organic EL element, (a) is the figure which formed the insulating film, (b) is the liquid prepared by diluting the metal alkoxide composition in the solvent on the insulating film in the solution It is the figure which applied. It is sectional drawing of the conventional organic EL element.

Explanation of symbols

10: Organic EL element 12: Substrate 14: Anode electrode 16: Organic layer 18: Cathode electrode 20: Insulating film 22: Film of organic / inorganic hybrid material

Claims (7)

A substrate,
An anode electrode formed on the substrate;
An organic layer laminated on the anode electrode;
A cathode electrode laminated on the organic layer;
An insulating film formed to cover the laminated anode electrode, organic layer, and cathode electrode and having at least a nitride film;
A film formed of an organic / inorganic hybrid material covering the insulating film and having a three-dimensional crosslink formed by a sol-gel reaction by a hydrolysis reaction of the metal alkoxide composition;
An organic EL element containing The organic EL element according to claim 1, wherein the insulating film includes an oxide film in addition to the nitride film. The organic EL element according to claim 2, wherein the nitride film and the oxide film are overlapped. Preparing a substrate;
Forming an anode electrode on the substrate;
Forming an organic layer on the anode electrode;
Forming a cathode electrode on the organic layer;
Forming an insulating film having at least a nitride film so as to cover the anode electrode, the organic layer, and the cathode electrode;
Applying a liquid prepared by diluting a metal alkoxide composition in a solvent onto the insulating film;
Forming the applied liquid into a film;
Curing the liquid into a film;
The manufacturing method of the organic EL element containing this. The method for producing an organic EL element according to claim 4, wherein the curing step includes a dehydration condensation reaction by a hydrolysis reaction performed in an atmosphere of 80 ° C. or less. 6. The method of manufacturing an organic EL element according to claim 4, wherein the applying step, the step of forming the liquid into a film, and the step of curing the liquid are performed in an inert gas atmosphere. The method for manufacturing an organic EL element according to claim 4, wherein the insulating film has an oxide film, and the step of forming the insulating film alternately forms the nitride film and the oxide film.

Images