WO2012165159A1 - Organic electroluminescent element and method for manufacturing same - Google Patents

Organic electroluminescent element and method for manufacturing same Download PDF

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Publication number
WO2012165159A1
WO2012165159A1 PCT/JP2012/062635 JP2012062635W WO2012165159A1 WO 2012165159 A1 WO2012165159 A1 WO 2012165159A1 JP 2012062635 W JP2012062635 W JP 2012062635W WO 2012165159 A1 WO2012165159 A1 WO 2012165159A1
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electrode
functional layer
support substrate
organic
layer
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PCT/JP2012/062635
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French (fr)
Japanese (ja)
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将啓 中村
山木　健之
正人 山名
貴裕 小柳
大貴 加藤
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パナソニック株式会社
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B33/00—Electroluminescent light sources
    • H05B33/10—Apparatus or processes specially adapted to the manufacture of electroluminescent light sources
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
    • H10K71/60—Forming conductive regions or layers, e.g. electrodes
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
    • H10K71/60—Forming conductive regions or layers, e.g. electrodes
    • H10K71/611—Forming conductive regions or layers, e.g. electrodes using printing deposition, e.g. ink jet printing

Definitions

  • the present invention relates to an organic electroluminescence element used for a lighting fixture, a liquid crystal backlight or various display devices, and a method for producing the same.
  • a typical example of the surface light emitter is an organic electroluminescence element (hereinafter referred to as “organic EL element”).
  • organic EL element a light transmissive second electrode 12 is provided on the surface (lower surface) of a light transmissive support substrate 11, and holes are injected into the surface (lower surface) of the second electrode 12.
  • the functional layer 16 including the layer 13, the hole transport layer 14, and the light emitting layer 15 is provided, and the light reflective first electrode 17 is provided on the surface (lower surface) of the functional layer 16.
  • the light emitted from the functional layer 16 by applying a voltage between the second electrode 12 and the first electrode 17 is extracted through the second electrode 12 and the support substrate 11.
  • the light transmissive second electrode 12 is made of a metal oxide such as ITO, IZO, AZO, GZO, FTO, or ATO as a transparent conductive material, and is subjected to a vacuum process such as sputtering or vacuum deposition. It is formed.
  • a metal oxide such as ITO, IZO, AZO, GZO, FTO, or ATO
  • a vacuum process such as sputtering or vacuum deposition. It is formed.
  • These film forming methods require expensive equipment and a large amount of energy, and techniques for reducing manufacturing costs and environmental burdens are required.
  • the refractive index of the transparent conductive film formed by these is higher than that of the glass support substrate, and in the case of an organic EL device, the total reflection loss due to the difference in refractive index at the interface with the front and rear layers reduces the light extraction efficiency. It is a factor.
  • the present invention has been made in view of the above points, and an object of the present invention is to provide a low-cost organic electroluminescence element that suppresses a short circuit and reduces the influence on operation reliability, and a method for manufacturing the same.
  • the present invention includes forming a functional layer (26) including at least a light emitting layer (25) on the first electrode (27) and then forming a second electrode (22) on the functional layer (26). It is a manufacturing method of an organic electroluminescent element. The method includes forming the second electrode by a wet process, and the second electrode (22) is light transmissive.
  • the method includes forming the first electrode (27) by a dry process.
  • the method includes forming the first electrode (27) on the support substrate (21) by a dry process, and forming the functional layer (26) on the first electrode (27) by a wet process. And forming the second electrode (22) on the functional layer (26) by a wet process.
  • one of the support substrate (21) and the first electrode (27) also serves as the other.
  • the method includes forming the functional layer (26) on a support substrate (21) that also serves as the first electrode (27) by a wet process, and forming the functional layer (26) on the functional layer (26) by a wet process. Forming a second electrode (22).
  • the method includes forming the second electrode (22) in a mesh shape.
  • the present invention includes a functional layer (26) including at least a light emitting layer (25) formed on the first electrode (27) and a second electrode (22) formed on the functional layer (26). It is the organic electroluminescent element provided.
  • a support substrate (21) is provided on the opposite side of the functional layer (26) of the first electrode (27), and the second electrode (22) is light transmissive.
  • the present invention comprises a functional layer (26) including a light emitting layer (25) formed on the first electrode (27) and a second electrode (22) formed on the functional layer (26).
  • Organic electroluminescence device The first electrode (27) is also formed as a support substrate (21), and the second electrode (22) is light transmissive.
  • the second electrode (22) is formed in a mesh shape.
  • the present invention can provide a low-cost organic electroluminescence element that suppresses a short circuit and reduces the influence on operation reliability.
  • FIG. 1 is a schematic cross-sectional view showing a first embodiment of the present invention. It is general
  • FIG. 3A is a schematic sectional view and
  • FIG. 3B is a partial plan view showing a third embodiment of the present invention. It is general
  • FIG. 1 shows a layer configuration of the organic EL element according to the first embodiment of the present invention.
  • the organic EL device of the first embodiment has a functional layer 26 having a first surface (lower surface) 261 and a second surface (upper surface) 262, and a first surface (lower surface) 271 and a second surface (upper surface) 272.
  • the functional layer 26 has a first electrode 27 disposed on the first surface 261 side, a first surface (lower surface) 221 and a second surface (upper surface) 222, and is disposed on the second surface 262 side of the functional layer 26.
  • the second electrode 22 is included.
  • the functional layer 26 is an organic functional layer including at least the light emitting layer 25 made of an organic functional material. In the example of FIG.
  • the organic EL element includes a support substrate 21 having a first surface (lower surface) 211 and a second surface (upper surface) 212, and a first electrode 27 formed on the second surface 212 of the support substrate 21.
  • a functional layer (organic layer) 26 including a light emitting layer 25, a hole transport layer 24, and a hole injection layer 23, and a light transmissive second electrode 22 formed on the second surface 262 of the functional layer 26.
  • the functional layer 26 is formed on the first electrode 27 (second surface 272) such that the first electrode 27 is interposed between the second surface 212 of the support substrate 21 and the first surface 261 of the functional layer 26. .
  • the functional layer 26 is formed by being laminated on one surface (second surface 272) of the first electrode 27.
  • the second surface 272 is a surface of the second electrode 22 on the functional layer 26 side ( It is formed smoother than the first surface 221). Accordingly, it is possible to reduce the influence of the irregularities on the surface of the first electrode 27 (second surface 272) on the functional layer 26. As a result, as shown in FIG. 5, the short circuit that is likely to occur in the functional layer 26 is suppressed as compared with the case where the functional layer 16 is formed on the surface of the second electrode 12 having a larger roughness than the surface of the first electrode 17. The influence on the operation reliability can be reduced.
  • the second electrode 22 can be formed on the functional layer 26 (second surface 262) by a wet process. Accordingly, it is possible to form a low-cost organic EL element that suppresses a short circuit that is likely to occur when the functional layer 16 is formed on the second electrode 12 formed by a wet process and reduces the influence on the operation reliability.
  • the support substrate 21 examples include a rigid transparent glass plate such as soda glass and non-alkali glass, a flexible transparent plastic plate such as polycarbonate and polyethylene terephthalate, and a metal film made of aluminum, copper, stainless steel, or the like. However, it is not limited to these. Moreover, although it is common in any kind of support substrate 21, in order to suppress the short circuit of an organic EL element, the smoothness of the surface (second surface 212) of the support substrate 21 is very important. In general, the metal film may have a rougher surface than glass or the like, but it is preferable to suppress the surface roughness to Ra 100 nm or less, and more preferably to Ra 10 nm or less. Thereby, the influence which the roughness of the surface of the support substrate 21 has on the first electrode 27 can be reduced, and the short circuit of the first electrode 27 can be easily suppressed.
  • a rigid transparent glass plate such as soda glass and non-alkali glass
  • a flexible transparent plastic plate such as polycarbonate and polyethylene terephthalate
  • the first electrode 27 can be formed as a cathode.
  • Such electrode material combinations include alkali metal and Al laminates, alkali metal and silver laminates, alkali metal halides and Al laminates, and alkali metal oxides and Al laminates. Bodies, laminates of alkaline earth metals and rare earth metals and Al, and alloys of these metal species with other metals, such as sodium, sodium-potassium alloy, lithium, magnesium, etc.
  • Examples thereof include a laminate with Al, a magnesium-silver mixture, a magnesium-indium mixture, an aluminum-lithium alloy, a LiF / Al mixture / laminate, an Al / Al 2 O 3 mixture, and the like. Further, in addition to those listed above, it is more preferable to insert a layer that promotes electron injection from the first electrode 27 into the light emitting layer 25, that is, an electron injection layer between the first electrode 27 and the light emitting layer 25. .
  • a material constituting the electron injection layer a material common to the material constituting the first electrode 27, a metal oxide such as titanium oxide and zinc oxide, and a dopant for promoting electron injection are mixed. However, it is not limited to these.
  • Examples of the organic electroluminescent material constituting the light emitting layer 25 include polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, the above dye bodies, and metal complex light emission.
  • luminescent materials such as Ir complexes, Os complexes, Pt complexes, and europium complexes, or compounds or polymers having these in the molecule It can be used suitably. These materials can be appropriately selected and used as necessary.
  • a low molecular to high molecular material having a small LUMO can be used as a material constituting the hole transport layer 24 .
  • an aromatic amine is added to a side chain or main chain of polyvinylcarbazole (PVCz), polypyridine, polyaniline, or the like.
  • PVCz polyvinylcarbazole
  • polypyridine polypyridine
  • polyaniline polyaniline
  • polymers containing aromatic amines such as polyarylene derivatives, but are not limited thereto.
  • Examples of the material constituting the hole injection layer 23 include organic materials including thiophene, triphenylmethane, hydrazoline, arylamine, hydrazone, stilbene, triphenylamine, and the like.
  • aromatic carbene derivatives such as polyvinyl carbazole (PVCz), polyethylene dioxythiophene: polystyrene sulfonate (PEDOT: PSS), TPD, etc., the above materials may be used alone, or two or more kinds of materials. May be used in combination.
  • the second electrode 22 can be formed as an anode.
  • the conductive material constituting the second electrode 22 include silver, indium-tin oxide (ITO), indium-zinc oxide (IZO), tin oxide, fine particles of metal such as Au, conductive polymer, conductive Organic material, dopant (donor or acceptor) -containing functional layer, a mixture of a conductor and a conductive organic material (including a polymer), and a mixture of these conductive material and non-conductive material. It is not limited.
  • Non-conductive materials include acrylic resin, polyethylene, polypropylene, polyethylene terephthalate, polymethyl methacrylate, polystyrene, polyethersulfone, polyarylate, polycarbonate resin, polyurethane, polyacrylonitrile, polyvinyl acetal, polyamide, polyimide, diacrylphthalate. Resins, cellulosic resins, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, other thermoplastic resins, and copolymers of two or more monomers constituting these resins, but are not limited to these Is not to be done. Moreover, in order to improve electroconductivity, you may perform doping using the following dopants. Examples of the dopant include, but are not limited to, sulfonic acid, Lewis acid, proton acid, alkali metal, alkaline earth metal, and the like.
  • the first electrode 27 is formed on one surface (second surface 212) of the support substrate 21.
  • Various formation methods can be adopted for the first electrode 27 according to the constituent material, and examples thereof include a non-wet process (dry process) and a wet process.
  • the non-wet process the first electrode 27 is formed without using a solvent, and examples thereof include a vacuum deposition method, a sputtering method, and a lamination method in which a metal thin film is thermocompression bonded.
  • the first electrode 27 is formed using a solvent.
  • a spin coating method, a casting method, a micro gravure coating method, a gravure coating method, a bar coating method, a roll coating method, a wire bar coating method examples thereof include a dip coating method, a spray coating method, a screen printing method, a flexographic printing method, an offset printing method, and an ink jet printing method. Since it is preferable that the first electrode 27 has less surface roughness (unevenness) than the second electrode 22, the first electrode 27 is preferably formed by a non-wet process that can form a smooth surface more easily than the wet process. .
  • the functional layer 26 is formed on one surface (second surface 272 opposite to the support substrate 21) of the first electrode 27 formed on the support substrate 21 (second surface 212).
  • Various formation methods can be adopted for the functional layer 26 depending on the constituent material, and examples thereof include the wet process described above.
  • the functional layer 26 can be sequentially formed in the order of the light emitting layer 25, the hole transport layer 24, and the hole injection layer 23 from the first electrode 27 side.
  • the second electrode 22 is formed on one surface (the second surface 262 opposite to the first electrode 27) of the functional layer 26 formed on the first electrode 27 on the support substrate 21.
  • the second electrode 22 can be formed by the above-described wet process, and in this case, a large-scale facility such as a vacuum deposition method is not required, and the cost can be reduced.
  • the second electrode When the second electrode is formed by a wet process, it is necessary to reduce the surface roughness on the second electrode in order to suppress a short circuit in the organic EL element having a configuration in which the functional layer is formed on the second electrode.
  • the second electrode portion defines a light emitting area, it is necessary to form a pattern in order to prevent a short circuit with the first electrode.
  • printing patterning methods such as bank formation after film formation, etching, screen printing and the like. Normally, bank formation and etching involve steps of resist coating, developing solution, and immersion in a resist stripping solution, and the second electrode formed by the wet process is easily damaged and may deteriorate the characteristics of the second electrode. The nature is very high.
  • the organic EL element supplies power to the functional layer 26 through the first electrode 27 and the second electrode 22, causes the light emitting layer 25 to emit light by the power supply, and emits the light from the second electrode 22 (second surface 222). It can be taken out from the support substrate 21 (first surface 211) via the first electrode 27.
  • FIG. 2 shows a second embodiment of the present invention.
  • one of the support substrate 21 and the first electrode 27 also serves as the other.
  • Other configurations are the same as those in FIG.
  • a process for forming only the first electrode 27 is also unnecessary, and the cost can be reduced.
  • a flexible metal is used for the support substrate 21.
  • the support substrate 21 is cheaper than the barrier film, has the same sealing performance, and can also serve as the first electrode 27, which can greatly reduce the cost.
  • the first electrode 27 is formed to also serve as the support substrate 21.
  • the first electrode 27 is not limited, but has a thickness (for example, ⁇ m order) larger than the thickness (for example, the nm order) of the first embodiment.
  • FIG. 3 shows a third embodiment of the present invention.
  • This organic EL element is the same as that shown in FIG. 1 except that the second electrode 22 is formed in a mesh shape.
  • the second electrode 22 can be formed of the above-described conductive material.
  • a metal material such as silver or copper or a conductive material such as carbon is formed on a thin wire, and a plurality of thin wires are formed. It can be formed by crossing appropriately in the vertical and horizontal directions.
  • the width of the thin wire can be about 1 to 100 ⁇ m, but is not limited thereto.
  • arbitrary things can be used also about the width space
  • the mesh-like second electrode 22 can be formed using a conductive paste by screen printing or the like, but is not limited thereto.
  • the shape of the mesh (opening) 30 of the mesh-like second electrode 22 in plan view can be set as appropriate.
  • the mesh-like second electrode 22 has a grid structure (lattice structure).
  • it can be formed in a square mesh 30 in plan view.
  • the mesh 30 can be formed in an arbitrary shape such as a triangle, a hexagon, or a circle in a plan view.
  • the second electrode 22 can easily take out light emitted from the light emitting layer 25 of the functional layer 26 through the mesh 30.
  • This organic EL element can reduce the resistivity and sheet resistance of the second electrode 22 as compared with the case where the second electrode 22 is a thin film formed of a conductive transparent oxide. It is possible to reduce luminance unevenness by reducing the resistance of the electrode 22.
  • FIG. 4 shows a fourth embodiment of the present invention.
  • one of the support substrate 21 and the first electrode 27 also serves as the other, as in the second embodiment.
  • Other configurations are the same as those in FIG.
  • Example 1 A support substrate was prepared, and a first electrode was formed on the support substrate (second surface) by a non-wet process (dry process).
  • a non-alkali glass plate No. 1737, manufactured by Corning
  • a first electrode cathode
  • Example 1 A support substrate was prepared, and a first electrode was formed on the support substrate (second surface) by a non-wet process (dry process).
  • a non-alkali glass plate No. 1737, manufactured by Corning
  • a first electrode cathode
  • Example 1 a red polymer (“Light Emitting Polymer ATS111RE” manufactured by American Dye Source Co.) was dissolved in THF solvent to 1 wt% (hereinafter referred to as “first solution”), and the first solution was prepared.
  • a light-emitting layer was formed by coating the first electrode (cathode) with a spin coater so as to have a film thickness of about 200 nm and baking it at 100 ° C. for 10 minutes.
  • TFB Poly [(9,9-dioctylfluorenyl-2,7-diyl) -co- (4,4 ′-(N- (4-sec-butylphenyl))) diphenyl amine)] (American Dye Source)
  • a solution (hereinafter referred to as “second solution”) prepared by dissolving “Hole Transport Polymer ADS259BE”) in THF solvent to 1 wt% is prepared, and the second solution is formed on the light emitting layer so that the film thickness is about 12 nm.
  • a TFB film was prepared by coating with a spin coater and baked at 200 ° C. for 10 minutes to form a hole transport layer.
  • PEDOT-PSS polyethylene dioxythiophene / polystyrene sulfonic acid
  • the third solution is prepared, and the third solution is applied onto the hole transport layer with a spin coater so that the film thickness of PEDOT-PSS is 30 nm, and is baked at 150 ° C. for 10 minutes. An injection layer was formed.
  • Example 2 ITO nanoparticle (particle size: about 40 nm, NanoTek (registered trademark) ITCW 15 wt% -G30 manufactured by CI Kasei Co., Ltd.) and methyl cellulose (METOLOSE (registered trademark) 60SH manufactured by Shin-Etsu Chemical Co., Ltd.) 5 wt% mixed (hereinafter referred to as “solution”). "Fourth solution”) is prepared, and the fourth solution is printed as an ink on a hole injection layer through a screen printer so that the film thickness is about 300 nm to form a pattern, which is dried at 120 ° C for 15 minutes. Thus, a second electrode (anode) was formed. As a result, an organic EL element having a layer structure as shown in FIG. 1 was obtained.
  • Example 2 A support substrate also serving as a first electrode was prepared, a functional layer was formed on the support substrate (second surface) by a wet process, and a second electrode was formed on the functional layer (second surface) by a wet process.
  • an aluminum foil about 30 ⁇ m thick
  • this support substrate was also used as the first electrode.
  • an organic EL element having a layer structure as shown in FIG. 2 was obtained in the same manner as in Example 1 except that the light emitting layer was formed on the smooth surface (second surface) side of the support substrate by the same method as in Example 1. It was.
  • Example 3 Highly conductive polyethylene dioxythiophene / polystyrene sulfonic acid (PEDOT-PSS) was applied on the hole injection layer to form a highly conductive polymer layer of about 200 nm. Further, using a silver paste material for printing on the surface, a mesh-like second electrode as shown in FIGS. 3A and 3B was formed by screen printing as an anode. The line width was about 40 ⁇ m, the pitch between line centers was about 1000 ⁇ m, and the mesh height was about 5 ⁇ m. Other than that was carried out similarly to Example 1, and obtained the organic EL element of a layer structure like FIG. 3A.
  • PEDOT-PSS polystyrene sulfonic acid
  • Example 4 Highly conductive polyethylene dioxythiophene / polystyrene sulfonic acid (PEDOT-PSS) was applied on the hole injection layer to form a highly conductive polymer layer of about 200 nm. Further, a silver paste material for printing was used on the surface, and a mesh-like second electrode as shown in FIG. 4 was formed by screen printing as an anode. The line width was about 40 ⁇ m, the pitch between line centers was about 1000 ⁇ m, and the mesh height was about 5 ⁇ m. Other than that was carried out similarly to Example 2, and obtained the organic EL element of a layer structure like FIG.
  • PEDOT-PSS polystyrene sulfonic acid
  • a non-alkali glass plate (No. 1737, manufactured by Corning) having a thickness of 0.7 mm was used as the support substrate.
  • Prepare a solution of ITO nanoparticles (particle diameter of about 40 nm, NanoTek (registered trademark) ITCW 15 wt% -G30 manufactured by C-I Kasei Co., Ltd.) and 5 wt% of methylcellulose (METOLOSE (registered trademark) 60SH manufactured by Shin-Etsu Chemical Co., Ltd.).
  • a pattern was formed by printing on a support substrate through a screen printer so that the film thickness was about 300 nm, and this was dried at 120 ° C. for 15 minutes to form a second electrode (anode).
  • PEDOT-PSS polyethylene dioxythiophene / polystyrene sulfonic acid
  • TFB Poly [(9,9-dioctylfluorenyl-2,7-diyl) -co- (4,4 ′-(N- (4-sec-butyphenyl))) diphenyl amine)] (manufactured by American Dye Source) “Hole Transport Polymer ADS259BE”) is prepared in a THF solvent so as to be 1 wt%, and the solution is applied onto the hole injection layer with a spin coater so that the film thickness is about 12 nm. The hole transport layer was formed by producing and baking this at 200 ° C. for 10 minutes.
  • a solution in which a red polymer (“Light Emitting Polymer ATS111RE” manufactured by American Dye Source Co., Ltd.) is dissolved to 1 wt% in a THF solvent is prepared, and the film thickness is about 200 nm on the hole transport layer.
  • the light emitting layer was formed by applying with a spin coater and baking it at 100 ° C. for 10 minutes.
  • an organic EL element was obtained by forming a first electrode (cathode) by depositing aluminum with a thickness of 80 nm on a support substrate by vacuum deposition.
  • Comparative Example 2 An organic EL device was obtained in the same manner as in Comparative Example 1 except that an aluminum foil (about 30 ⁇ m thick) was used as the support substrate and the light emitting layer was formed on the smooth surface side of the support substrate by the same method as in Comparative Example 1. . That is, in Comparative Example 1, the second electrode (anode), the hole injection layer, the hole transport layer, the light emitting layer, and the first electrode (cathode) are sequentially formed on the smooth surface of the support substrate. The second electrode (cathode), the light emitting layer, the hole transport layer, the hole injection layer, and the first electrode (anode) are sequentially formed on the smooth surface of the support substrate.
  • Example 1 (FIG. 1) -4 (FIG. 4) are the second surfaces (222) of the second electrodes (22), respectively, and the front surfaces of Comparative Examples 1 and 2 are the support substrates, respectively. It is the surface (the surface of the support substrate opposite to the second electrode).
  • the front luminance of Examples 1 to 4 is equivalent to that of Comparative Example 1, but the driving voltage of Comparative Example 1 is higher than that of Examples 1 to 4. Furthermore, light emission was not able to be confirmed about the comparative example 2 which formed the laminated structure in order on the metal foil. Therefore, a functional layer (organic layer) is formed on a light-transmitting anode (second electrode) formed by a wet process by using a layered structure reverse to the normal element formation order as shown in FIG.

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Abstract

This method for manufacturing organic electroluminescent elements includes a step of forming, by lamination, a functional layer (26) on a first electrode (27), said functional layer including at least a light emitting layer (25), then, forming, by lamination, a second electrode (22) on the functional layer (26). The method includes formation of the second electrode (22) by wet process, and the second electrode (22) has light transmitting characteristics.

Description

有機エレクトロルミネッセンス素子及びその製造方法Organic electroluminescence device and method for manufacturing the same
　本発明は、照明器具、液晶バックライト又は各種の表示装置などに用いられる有機エレクトロルミネッセンス素子及びその製造方法に関するものである。 The present invention relates to an organic electroluminescence element used for a lighting fixture, a liquid crystal backlight or various display devices, and a method for producing the same.
　面発光体の代表的なものとして、有機エレクトロルミネッセンス素子（以下「有機ＥＬ素子」という）がある。この有機ＥＬ素子は、図５に示すように、光透過性の支持基板１１の表面（下面）に光透過性の第２電極１２を設け、この第２電極１２の表面（下面）にホール注入層１３とホール輸送層１４と発光層１５からなる機能層１６を設けると共に、機能層１６の表面（下面）に光反射性の第１電極１７を設けることによって形成されている。そして、第２電極１２と第１電極１７との間に電圧を印加することによって機能層１６で発光した光は、第２電極１２及び支持基板１１を透過して取り出される。 A typical example of the surface light emitter is an organic electroluminescence element (hereinafter referred to as “organic EL element”). As shown in FIG. 5, in this organic EL element, a light transmissive second electrode 12 is provided on the surface (lower surface) of a light transmissive support substrate 11, and holes are injected into the surface (lower surface) of the second electrode 12. The functional layer 16 including the layer 13, the hole transport layer 14, and the light emitting layer 15 is provided, and the light reflective first electrode 17 is provided on the surface (lower surface) of the functional layer 16. The light emitted from the functional layer 16 by applying a voltage between the second electrode 12 and the first electrode 17 is extracted through the second electrode 12 and the support substrate 11.
　近年、フレキシブルな支持基板を用いてロールｔｏロールで各層を塗布形成する方法が、有機ＥＬ素子の低コスト化を達成する手段として注目されている。しかし、一般的にフレキシブルな支持基板としては、封止性能のあるバリアフィルム付きフィルムの使用が想定されるが、同フィルムの価格は高く、低コスト化を達成するためには大きな障害となる。 In recent years, a method of applying and forming each layer by roll-to-roll using a flexible support substrate has attracted attention as a means for achieving cost reduction of organic EL elements. However, as a flexible support substrate, it is assumed that a film with a barrier film having sealing performance is used. However, the price of the film is high, and it is a great obstacle to achieve cost reduction.
　また、一般的に光透過性の第２電極１２には、ＩＴＯ、ＩＺＯ、ＡＺＯ，ＧＺＯ，ＦＴＯ，ＡＴＯなどの金属酸化物を透明導電材料として用い、スパッタ法や真空蒸着法などの真空プロセスで形成される。これらの製膜方法は高価な装置や多量のエネルギーが必要であり、製造コストや環境負荷を低減する技術が求められている。さらに、これらで製膜した透明導電膜の屈折率はガラス支持基板に比べて高く、有機ＥＬ素子にした場合、前後の層との界面における屈折率差による全反射ロスが光取り出し効率を低下させる要因になっている。 In general, the light transmissive second electrode 12 is made of a metal oxide such as ITO, IZO, AZO, GZO, FTO, or ATO as a transparent conductive material, and is subjected to a vacuum process such as sputtering or vacuum deposition. It is formed. These film forming methods require expensive equipment and a large amount of energy, and techniques for reducing manufacturing costs and environmental burdens are required. Furthermore, the refractive index of the transparent conductive film formed by these is higher than that of the glass support substrate, and in the case of an organic EL device, the total reflection loss due to the difference in refractive index at the interface with the front and rear layers reduces the light extraction efficiency. It is a factor.
　これらを克服するために、導電性ナノ粒子を含有する溶液を用いて塗布や印刷などにより、透明導電膜を形成する方法が提案されている（日本国特許出願公開番号２００９－１８１８５６参照）。この方法によると、真空プロセスが必要でないため、プロセスコストを抑えられるだけでなく、導電性ナノ粒子を保持するバインダー材料の選択により、透明導電膜の屈折率を制御でき、光学的に有利な素子構造を形成することができる。しかし、このような導電性ナノ粒子とバインダーを混合した溶液を用いて塗布形成する膜では、一般的に有機ＥＬなどの有機半導体デバイスに使用されるガラス支持基板表面と比較して表面粗さが大きい。この比較的大きな表面粗さは含有する粒子に起因し、この膜上に発光層を含む機能層を積層して有機ＥＬ素子を形成した場合、短絡の発生や動作信頼性に影響を及ぼす可能性が非常に高い。そこで、これを緩和する方法として、ナノ粒子を含有した透明導電膜上に粒子を含有しない、または、含有量の少ないバインダー材料をオーバーコートするなどして平坦性を改善する手法が開示されている（日本国特許出願公開番号２００９－５０５３５８参照）。しかし、このような方法では透明導電膜に比べオーバーコート層の導電性が低いため、電極としての電気特性も低下してしまうおそれがあり、根本的な解決にはならない。 In order to overcome these problems, a method of forming a transparent conductive film by coating or printing using a solution containing conductive nanoparticles has been proposed (see Japanese Patent Application Publication No. 2009-181856). According to this method, since a vacuum process is not necessary, not only the process cost can be suppressed, but also the optically advantageous element that can control the refractive index of the transparent conductive film by selecting the binder material holding the conductive nanoparticles. A structure can be formed. However, in a film formed by coating using a solution in which conductive nanoparticles and a binder are mixed, the surface roughness is generally higher than that of a glass supporting substrate surface used in organic semiconductor devices such as organic EL. large. This relatively large surface roughness is caused by the contained particles, and when an organic EL device is formed by laminating a functional layer including a light emitting layer on this film, it may affect the occurrence of short circuits and operational reliability. Is very expensive. Therefore, as a method for alleviating this, a technique for improving flatness by overcoating a binder material containing no nanoparticles or a low content on a transparent conductive film containing nanoparticles has been disclosed. (See Japanese Patent Application Publication No. 2009-505358). However, in such a method, since the conductivity of the overcoat layer is lower than that of the transparent conductive film, there is a possibility that the electrical characteristics as an electrode may be deteriorated, which is not a fundamental solution.
　本発明は上記の点に鑑みてなされたものであり、短絡を抑制し、動作信頼性への影響を低減した低コストの有機エレクトロルミネッセンス素子及びその製造方法を提供することを目的とする。 The present invention has been made in view of the above points, and an object of the present invention is to provide a low-cost organic electroluminescence element that suppresses a short circuit and reduces the influence on operation reliability, and a method for manufacturing the same.
　本発明は、少なくとも発光層（２５）を含む機能層（２６）を第１電極（２７）に積層形成した後、前記機能層（２６）に第２電極（２２）を積層形成することを含む有機エレクトロルミネッセンス素子の製造方法である。この方法は、ウェットプロセスにより前記第２電極を形成することを含み、前記第２電極（２２）は光透過性を有する。 The present invention includes forming a functional layer (26) including at least a light emitting layer (25) on the first electrode (27) and then forming a second electrode (22) on the functional layer (26). It is a manufacturing method of an organic electroluminescent element. The method includes forming the second electrode by a wet process, and the second electrode (22) is light transmissive.
　一実施形態において、前記方法は、ドライプロセスにより前記第１電極（２７）を形成することを含む。 In one embodiment, the method includes forming the first electrode (27) by a dry process.
　一実施形態において、前記方法は、ドライプロセスにより支持基板（２１）に前記第１電極（２７）を形成すること、ウェットプロセスにより前記第１電極（２７）に前記機能層（２６）を形成すること、及びウェットプロセスにより前記機能層（２６）に前記第２電極（２２）を形成することを含む。 In one embodiment, the method includes forming the first electrode (27) on the support substrate (21) by a dry process, and forming the functional layer (26) on the first electrode (27) by a wet process. And forming the second electrode (22) on the functional layer (26) by a wet process.
　一実施形態において、支持基板（２１）と第１電極（２７）との一方が他方を兼ねる。 In one embodiment, one of the support substrate (21) and the first electrode (27) also serves as the other.
　一実施形態において、前記方法は、ウェットプロセスにより前記第１電極（２７）を兼ねる支持基板（２１）に前記機能層（２６）を形成すること、及びウェットプロセスにより前記機能層（２６）に前記第２電極（２２）を形成することを含む。 In one embodiment, the method includes forming the functional layer (26) on a support substrate (21) that also serves as the first electrode (27) by a wet process, and forming the functional layer (26) on the functional layer (26) by a wet process. Forming a second electrode (22).
　一実施形態において、前記方法は、前記第２電極（２２）をメッシュ状に形成することを含む。 In one embodiment, the method includes forming the second electrode (22) in a mesh shape.
　本発明は、第１電極（２７）に積層形成される、少なくとも発光層（２５）を含む機能層（２６）と、この機能層（２６）に積層形成される第２電極（２２）とを備えた有機エレクトロルミネッセンス素子である。前記第１電極（２７）の機能層（２６）と反対側に支持基板（２１）を備え、前記第２電極（２２）は光透過性を有する。 The present invention includes a functional layer (26) including at least a light emitting layer (25) formed on the first electrode (27) and a second electrode (22) formed on the functional layer (26). It is the organic electroluminescent element provided. A support substrate (21) is provided on the opposite side of the functional layer (26) of the first electrode (27), and the second electrode (22) is light transmissive.
　本発明は、第１電極（２７）に積層形成される、発光層（２５）を含む機能層（２６）と、この機能層（２６）に積層形成される第２電極（２２）とを備えた有機エレクトロルミネッセンス素子である。前記第１電極（２７）は支持基板（２１）としても形成され、前記第２電極（２２）は光透過性を有する。 The present invention comprises a functional layer (26) including a light emitting layer (25) formed on the first electrode (27) and a second electrode (22) formed on the functional layer (26). Organic electroluminescence device. The first electrode (27) is also formed as a support substrate (21), and the second electrode (22) is light transmissive.
　一実施形態において、前記第２電極（２２）がメッシュ状に形成されている。 In one embodiment, the second electrode (22) is formed in a mesh shape.
　本発明は、短絡を抑制し、動作信頼性への影響を低減した低コストの有機エレクトロルミネッセンス素子を得ることができるものである。 The present invention can provide a low-cost organic electroluminescence element that suppresses a short circuit and reduces the influence on operation reliability.
　本発明の好ましい実施形態をさらに詳細に記述する。本発明の他の特徴および利点は、以下の詳細な記述および添付図面に関連して一層良く理解されるものである。
本発明の第１実施形態を示す概略の断面図である。 本発明の第２実施形態を示す概略の断面図である。 本発明の第３実施形態を示し、図３Ａは概略の断面図、図３Ｂは一部の平面図である。 本発明の第４実施形態を示す概略の断面図である。 従来例を示す概略の断面図である。 Preferred embodiments of the invention are described in further detail. Other features and advantages of the present invention will be better understood with reference to the following detailed description and accompanying drawings.
1 is a schematic cross-sectional view showing a first embodiment of the present invention. It is general | schematic sectional drawing which shows 2nd Embodiment of this invention. FIG. 3A is a schematic sectional view and FIG. 3B is a partial plan view showing a third embodiment of the present invention. It is general | schematic sectional drawing which shows 4th Embodiment of this invention. It is general | schematic sectional drawing which shows a prior art example.
　以下、本発明を実施するための形態を説明する。 Hereinafter, modes for carrying out the present invention will be described.
　（第１実施形態）
　本発明の第１実施形態に係る有機ＥＬ素子の層構成を図１に示す。第１実施形態の有機ＥＬ素子は、第１表面（下面）２６１及び第２表面（上面）２６２を有する機能層２６と、第１表面（下面）２７１及び第２表面（上面）２７２を有し機能層２６の第１表面２６１の側に配置される第１電極２７と、第１表面（下面）２２１及び第２表面（上面）２２２を有し機能層２６の第２表面２６２の側に配置される第２電極２２とを含む。機能層２６は、有機機能性材料からなる発光層２５を少なくとも含む有機機能層である。図１の例では、この有機ＥＬ素子は、第１表面（下面）２１１及び第２表面（上面）２１２を有する支持基板２１、支持基板２１の第２表面２１２上に形成された第１電極２７、及び発光層２５とホール輸送層２４とホール注入層２３とを備えた機能層（有機層）２６、機能層２６の第２表面２６２上に形成された光透過性の第２電極２２を具備するものである。機能層２６は、第１電極２７が支持基板２１の第２表面２１２と機能層２６の第１表面２６１との間に介在するように第１電極２７（第２表面２７２）上に形成される。このように、機能層２６は第１電極２７の一方の表面（第２表面２７２）に積層して形成されるが、この第２表面２７２は、第２電極２２の機能層２６側の表面（第１表面２２１）よりも平滑に形成されている。従って、第１電極２７の表面（第２表面２７２）の凹凸が機能層２６に与える影響を少なくすることができる。その結果、図５に示すように、第１電極１７の表面よりも粗さの大きい第２電極１２の表面に機能層１６を形成する場合に比べて、機能層２６に生じやすい短絡を抑制し、動作信頼性への影響を低減することができるものである。また、第２電極２２はウェットプロセスで機能層２６（第２表面２６２）上に形成することができる。従って、ウェットプロセスで形成した第２電極１２上に機能層１６を形成した場合に生じやすい短絡を抑制し、動作信頼性への影響を低減した低コストの有機ＥＬ素子を形成することができる。 (First embodiment)
FIG. 1 shows a layer configuration of the organic EL element according to the first embodiment of the present invention. The organic EL device of the first embodiment has a functional layer 26 having a first surface (lower surface) 261 and a second surface (upper surface) 262, and a first surface (lower surface) 271 and a second surface (upper surface) 272. The functional layer 26 has a first electrode 27 disposed on the first surface 261 side, a first surface (lower surface) 221 and a second surface (upper surface) 222, and is disposed on the second surface 262 side of the functional layer 26. The second electrode 22 is included. The functional layer 26 is an organic functional layer including at least the light emitting layer 25 made of an organic functional material. In the example of FIG. 1, the organic EL element includes a support substrate 21 having a first surface (lower surface) 211 and a second surface (upper surface) 212, and a first electrode 27 formed on the second surface 212 of the support substrate 21. And a functional layer (organic layer) 26 including a light emitting layer 25, a hole transport layer 24, and a hole injection layer 23, and a light transmissive second electrode 22 formed on the second surface 262 of the functional layer 26. To do. The functional layer 26 is formed on the first electrode 27 (second surface 272) such that the first electrode 27 is interposed between the second surface 212 of the support substrate 21 and the first surface 261 of the functional layer 26. . As described above, the functional layer 26 is formed by being laminated on one surface (second surface 272) of the first electrode 27. The second surface 272 is a surface of the second electrode 22 on the functional layer 26 side ( It is formed smoother than the first surface 221). Accordingly, it is possible to reduce the influence of the irregularities on the surface of the first electrode 27 (second surface 272) on the functional layer 26. As a result, as shown in FIG. 5, the short circuit that is likely to occur in the functional layer 26 is suppressed as compared with the case where the functional layer 16 is formed on the surface of the second electrode 12 having a larger roughness than the surface of the first electrode 17. The influence on the operation reliability can be reduced. The second electrode 22 can be formed on the functional layer 26 (second surface 262) by a wet process. Accordingly, it is possible to form a low-cost organic EL element that suppresses a short circuit that is likely to occur when the functional layer 16 is formed on the second electrode 12 formed by a wet process and reduces the influence on the operation reliability.
　上記の支持基板２１としては、例えばソーダガラスや無アルカリガラス等のリジッドな透明ガラス板、ポリカーボネートやポリエチレンテレフタレート等のフレキシブルな透明プラスチック板、アルミニウム・銅・ステンレスなどからなる金属フィルムなど、任意のものを用いることができるが、これらに限定されるものではない。また、何れの種類の支持基板２１においても共通するが、有機ＥＬ素子の短絡を抑制するために、支持基板２１の表面（第２表面２１２）の平滑性が非常に重要である。一般的に、金属フィルムはガラスなどに比べ表面が粗いことがあるが、表面粗さＲａ１００ｎｍ以下に抑えることが好ましく、Ｒａ１０ｎｍ以下に抑えることがさらに好ましい。これにより、支持基板２１の表面の粗さが第１電極２７に与える影響を少なくすることができ、第１電極２７の短絡を抑制しやすくなるものである。 Examples of the support substrate 21 include a rigid transparent glass plate such as soda glass and non-alkali glass, a flexible transparent plastic plate such as polycarbonate and polyethylene terephthalate, and a metal film made of aluminum, copper, stainless steel, or the like. However, it is not limited to these. Moreover, although it is common in any kind of support substrate 21, in order to suppress the short circuit of an organic EL element, the smoothness of the surface (second surface 212) of the support substrate 21 is very important. In general, the metal film may have a rougher surface than glass or the like, but it is preferable to suppress the surface roughness to Ra 100 nm or less, and more preferably to Ra 10 nm or less. Thereby, the influence which the roughness of the surface of the support substrate 21 has on the first electrode 27 can be reduced, and the short circuit of the first electrode 27 can be easily suppressed.
　第１電極２７は陰極として形成することができる。第１電極２７を構成する材料としては、ＡｌやＡｇなど、もしくはこれら金属を含む化合物を用いることができるが、Ａｌと他の電極材料を組み合わせて積層構造などとして構成するものであっても良い。このような電極材料の組み合わせとしては、アルカリ金属とＡｌとの積層体、アルカリ金属と銀との積層体、アルカリ金属のハロゲン化物とＡｌとの積層体、アルカリ金属の酸化物とＡｌとの積層体、アルカリ土類金属や希土類金属とＡｌとの積層体、これらの金属種と他の金属との合金などが挙げられ、具体的には、例えばナトリウム、ナトリウム－カリウム合金、リチウム、マグネシウムなどとＡｌとの積層体、マグネシウム－銀混合物、マグネシウム－インジウム混合物、アルミニウム－リチウム合金、ＬｉＦ／Ａｌ混合物／積層体、Ａｌ／Ａｌ2Ｏ3混合物などを例として挙げることができる。さらに、上記に列挙したもの以外についても、第１電極２７から発光層２５への電子注入を促進させる層、すなわち電子注入層を第１電極２７と発光層２５の間に挿入することはより好ましい。電子注入層を構成する材料としては、上記の第１電極２７を構成する材料と共通のもの、酸化チタン、酸化亜鉛などの金属酸化物、上記材料を含めて、電子注入を促進させるドーパントを混合した有機半導体材料などが挙げられるが、これらに限定されるものではない。 The first electrode 27 can be formed as a cathode. As the material constituting the first electrode 27, Al, Ag, or the like, or a compound containing these metals can be used, but a layered structure or the like may be constituted by combining Al and another electrode material. . Such electrode material combinations include alkali metal and Al laminates, alkali metal and silver laminates, alkali metal halides and Al laminates, and alkali metal oxides and Al laminates. Bodies, laminates of alkaline earth metals and rare earth metals and Al, and alloys of these metal species with other metals, such as sodium, sodium-potassium alloy, lithium, magnesium, etc. Examples thereof include a laminate with Al, a magnesium-silver mixture, a magnesium-indium mixture, an aluminum-lithium alloy, a LiF / Al mixture / laminate, an Al / Al 2 O 3 mixture, and the like. Further, in addition to those listed above, it is more preferable to insert a layer that promotes electron injection from the first electrode 27 into the light emitting layer 25, that is, an electron injection layer between the first electrode 27 and the light emitting layer 25. . As a material constituting the electron injection layer, a material common to the material constituting the first electrode 27, a metal oxide such as titanium oxide and zinc oxide, and a dopant for promoting electron injection are mixed. However, it is not limited to these.
　発光層２５を構成する有機エレクトロルミネッセンス材料としては、ポリパラフェニレンビニレン誘導体、ポリチオフェン誘導体、ポリパラフェニレン誘導体、ポリシラン誘導体、ポリアセチレン誘導体等、ポリフルオレン誘導体、ポリビニルカルバゾール誘導体、上記色素体、金属錯体系発光材料を高分子化したもの等や、アントラセン、ナフタレン、ピレン、テトラセン、コロネン、ペリレン、フタロペリレン、ナフタロペリレン、ジフェニルブタジエン、テトラフェニルブタジエン、クマリン、オキサジアゾール、ビスベンゾキサゾリン、ビススチリル、シクロペンタジエン、クマリン、オキサジアゾール、ビスベンゾキサゾリン、ビススチリル、シクロペンタジエン、キノリン金属錯体、トリス（８－ヒドロキシキノリナート）アルミニウム錯体、トリス（４－メチル－８－キノリナート）アルミニウム錯体、トリス（５－フェニル－８－キノリナート）アルミニウム錯体、アミノキノリン金属錯体、ベンゾキノリン金属錯体、トリ－（ｐ－ターフェニル－４－イル）アミン、ピラン、キナクリドン、ルブレン、及びこれらの誘導体、あるいは、１－アリール－２，５－ジ（２－チエニル）ピロール誘導体、ジスチリルベンゼン誘導体、スチリルアリーレン誘導体、スチリルアミン誘導体、及びこれらの発光性化合物からなる基を分子の一部分に有する化合物等が挙げられる。また上記化合物に代表される蛍光色素由来の化合物のみならず、いわゆる燐光発光材料、例えばＩｒ錯体、Ｏｓ錯体、Ｐｔ錯体、ユーロピウム錯体等々の発光材料、又はそれらを分子内に有する化合物若しくは高分子も好適に用いることができる。これらの材料は、必要に応じて、適宜選択して用いることができる。 Examples of the organic electroluminescent material constituting the light emitting layer 25 include polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, the above dye bodies, and metal complex light emission. Polymerized materials, anthracene, naphthalene, pyrene, tetracene, coronene, perylene, phthaloperylene, naphthaloperylene, diphenylbutadiene, tetraphenylbutadiene, coumarin, oxadiazole, bisbenzoxazoline, bisstyryl, cyclopentadiene, coumarin , Oxadiazole, bisbenzoxazoline, bisstyryl, cyclopentadiene, quinoline metal complex, tris (8-hydroxyquinolinate) a Minium complex, tris (4-methyl-8-quinolinato) aluminum complex, tris (5-phenyl-8-quinolinato) aluminum complex, aminoquinoline metal complex, benzoquinoline metal complex, tri- (p-terphenyl-4-yl) ) Amine, pyran, quinacridone, rubrene, and derivatives thereof, or 1-aryl-2,5-di (2-thienyl) pyrrole derivative, distyrylbenzene derivative, styrylarylene derivative, styrylamine derivative, and light emission thereof And compounds having a group consisting of a functional compound in a part of the molecule. Further, not only compounds derived from fluorescent dyes typified by the above compounds, but also so-called phosphorescent materials, for example, luminescent materials such as Ir complexes, Os complexes, Pt complexes, and europium complexes, or compounds or polymers having these in the molecule It can be used suitably. These materials can be appropriately selected and used as necessary.
　ホール輸送層２４を構成する材料としては、ＬＵＭＯが小さい低分子～高分子材料を用いることができ、例えば、ポリビニルカルバゾール（ＰＶＣｚ）や、ポリピリジン、ポリアニリンなどの側鎖や主鎖に芳香族アミンを有するポリアリーレン誘導体などの芳香族アミンを含むポリマーなどが挙げられるが、これらに限定されるものではない。 As a material constituting the hole transport layer 24, a low molecular to high molecular material having a small LUMO can be used. For example, an aromatic amine is added to a side chain or main chain of polyvinylcarbazole (PVCz), polypyridine, polyaniline, or the like. Examples thereof include polymers containing aromatic amines such as polyarylene derivatives, but are not limited thereto.
　ホール注入層２３を構成する材料としては、チオフェン、トリフェニルメタン、ヒドラゾリン、アリールアミン、ヒドラゾン、スチルベン、トリフェニルアミンなどを含む有機材料が挙げられる。具体的には、ポリビニルカルバゾール（ＰＶＣｚ）、ポリエチレンジオキシチオフェン：ポリスチレンスルホネート（ＰＥＤＯＴ：ＰＳＳ）、ＴＰＤなどの芳香族アミン誘導体などで、上記材料を単独で用いてもよく、また二種類以上の材料を組み合わせて用いてもよい。 Examples of the material constituting the hole injection layer 23 include organic materials including thiophene, triphenylmethane, hydrazoline, arylamine, hydrazone, stilbene, triphenylamine, and the like. Specifically, aromatic carbene derivatives such as polyvinyl carbazole (PVCz), polyethylene dioxythiophene: polystyrene sulfonate (PEDOT: PSS), TPD, etc., the above materials may be used alone, or two or more kinds of materials. May be used in combination.
　第２電極２２は陽極として形成することができる。第２電極２２を構成する導電性物質としては、銀、インジウム－錫酸化物（ＩＴＯ）、インジウム－亜鉛酸化物（ＩＺＯ）、錫酸化物、Ａｕ等の金属の微粒子、導電性高分子、導電性の有機材料、ドーパント（ドナーまたはアクセプタ）含有機能層、導電体と導電性有機材料（高分子含む）の混合物、これら導電性材料と非導電性材料の混合物を挙げることができるが、これらに限定されるものではない。また、非導電性材料としてはアクリル樹脂、ポリエチレン、ポリプロピレン、ポリエチレンテレフタレート、ポリメチルメタクリレート、ポリスチレン、ポリエーテルスルホン、ポリアリレート、ポリカーボネート樹脂、ポリウレタン、ポリアクリルニトリル、ポリビニルアセタール、ポリアミド、ポリイミド、ジアクリルフタレート樹脂、セルロース系樹脂、ポリ塩化ビニル、ポリ塩化ビニリデン、ポリ酢酸ビニル、その他の熱可塑性樹脂や、これらの樹脂を構成する単量体の２種以上の共重合体が挙げられるが、これらに限定されるものではない。また、導電性を高めるために、以下のようなドーパントを用いたドーピングを行っても良い。ドーパントとしては、スルホン酸、ルイス酸、プロトン酸、アルカリ金属、アルカリ土類金属などが挙げられるが、これらに限定されるものではない。 The second electrode 22 can be formed as an anode. Examples of the conductive material constituting the second electrode 22 include silver, indium-tin oxide (ITO), indium-zinc oxide (IZO), tin oxide, fine particles of metal such as Au, conductive polymer, conductive Organic material, dopant (donor or acceptor) -containing functional layer, a mixture of a conductor and a conductive organic material (including a polymer), and a mixture of these conductive material and non-conductive material. It is not limited. Non-conductive materials include acrylic resin, polyethylene, polypropylene, polyethylene terephthalate, polymethyl methacrylate, polystyrene, polyethersulfone, polyarylate, polycarbonate resin, polyurethane, polyacrylonitrile, polyvinyl acetal, polyamide, polyimide, diacrylphthalate. Resins, cellulosic resins, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, other thermoplastic resins, and copolymers of two or more monomers constituting these resins, but are not limited to these Is not to be done. Moreover, in order to improve electroconductivity, you may perform doping using the following dopants. Examples of the dopant include, but are not limited to, sulfonic acid, Lewis acid, proton acid, alkali metal, alkaline earth metal, and the like.
　以下に、上記の有機ＥＬ素子の製造方法を説明する。 Below, the manufacturing method of said organic EL element is demonstrated.
　まず、支持基板２１の一方の表面（第２表面２１２）に第１電極２７を形成する。第１電極２７はその構成材料に応じて、各種の形成方法を採用することができるが、例えば、非ウェットプロセス（ドライプロセス）やウェットプロセスを挙げることができる。非ウェットプロセスは溶剤を使用しないで第１電極２７を形成するものであり、真空蒸着法、スパッタリング法、金属薄膜を熱圧着するラミネート法など挙げることができる。ウェットプロセスは溶剤を使用して第１電極２７を形成するものであり、例えば、スピンコート法、キャスティング法、マイクログラビアコート法、グラビアコート法、バーコート法、ロールコート法、ワイアーバーコート法、ディップコート法、スプレーコート法、スクリーン印刷法、フレキソ印刷法、オフセット印刷法、インクジェットプリント法などを挙げることができる。第１電極２７は第２電極２２よりも表面の粗さ（凹凸）が少ない方が好ましいので、第１電極２７はウェットプロセスよりも平滑な表面を形成しやすい非ウェットプロセスで形成するのが好ましい。 First, the first electrode 27 is formed on one surface (second surface 212) of the support substrate 21. Various formation methods can be adopted for the first electrode 27 according to the constituent material, and examples thereof include a non-wet process (dry process) and a wet process. In the non-wet process, the first electrode 27 is formed without using a solvent, and examples thereof include a vacuum deposition method, a sputtering method, and a lamination method in which a metal thin film is thermocompression bonded. In the wet process, the first electrode 27 is formed using a solvent. For example, a spin coating method, a casting method, a micro gravure coating method, a gravure coating method, a bar coating method, a roll coating method, a wire bar coating method, Examples thereof include a dip coating method, a spray coating method, a screen printing method, a flexographic printing method, an offset printing method, and an ink jet printing method. Since it is preferable that the first electrode 27 has less surface roughness (unevenness) than the second electrode 22, the first electrode 27 is preferably formed by a non-wet process that can form a smooth surface more easily than the wet process. .
　次に、支持基板２１（第２表面２１２）に形成された第１電極２７の一方の表面（支持基板２１と反対側の第２表面２７２）に機能層２６を形成する。機能層２６はその構成材料に応じて、各種の形成方法を採用することができるが、例えば、上記のウェットプロセスを挙げることができる。機能層２６は第１電極２７側から発光層２５、ホール輸送層２４、ホール注入層２３の順で順次形成することができる。 Next, the functional layer 26 is formed on one surface (second surface 272 opposite to the support substrate 21) of the first electrode 27 formed on the support substrate 21 (second surface 212). Various formation methods can be adopted for the functional layer 26 depending on the constituent material, and examples thereof include the wet process described above. The functional layer 26 can be sequentially formed in the order of the light emitting layer 25, the hole transport layer 24, and the hole injection layer 23 from the first electrode 27 side.
　塗布法などのウェットプロセスで機能層２６の各層を積層した場合、下地となる層を溶解させてしまうこと、機能層２６の上に次層の塗布溶液が均一に広がらない、濡れ性が悪いなどの問題がある。図５に示すような一般的な有機ＥＬ素子の機能層形成順では問題にはならなかった場合でも、本実施形態のように逆順の構成にすると、上記の問題が顕著に現れてくる場合がある。このような問題が生じた場合、例えば膜厚については、溶解する分を考慮に入れて、狙いの膜厚以上の膜を形成しておくなどが１つの方法として挙げられる。また、濡れ性を改善するためには、塗布溶液に濡れ性を向上させる溶媒（アルコールなど）を添加する方法などが挙げられる。 When each layer of the functional layer 26 is laminated by a wet process such as a coating method, the underlying layer is dissolved, the coating solution of the next layer does not spread uniformly on the functional layer 26, and the wettability is poor. There is a problem. Even when the functional layer formation order of the general organic EL element as shown in FIG. 5 does not cause a problem, the above problem may appear remarkably when the reverse order is configured as in this embodiment. is there. When such a problem occurs, for example, with regard to the film thickness, taking into account the amount to be dissolved, a film having a thickness larger than the target film thickness is formed as one method. Moreover, in order to improve wettability, the method etc. which add the solvent (alcohol etc.) which improve wettability to a coating solution are mentioned.
　次に、支持基板２１上の第１電極２７に形成された機能層２６の一方の表面（第１電極２７と反対側の第２表面２６２）に第２電極２２を形成する。第２電極２２は上記のウェットプロセスで形成することができ、この場合、真空蒸着法などのような大掛かりな設備を必要とせず、低コスト化を図ることができるものである。 Next, the second electrode 22 is formed on one surface (the second surface 262 opposite to the first electrode 27) of the functional layer 26 formed on the first electrode 27 on the support substrate 21. The second electrode 22 can be formed by the above-described wet process, and in this case, a large-scale facility such as a vacuum deposition method is not required, and the cost can be reduced.
　ウェットプロセスで第２電極を形成した場合、第２電極上に機能層を形成する構成の有機ＥＬ素子については短絡を抑制するため、第２電極上の表面粗さを低減する必要がある。一般的に第２電極部分は発光エリアを規定するため、第１電極との短絡を防ぐためにパターニング形成する必要がある。これらパターニングをするためには膜形成後のバンク形成やエッチング、スクリーン印刷などによる印刷パターニングの方法がある。通常、バンク形成やエッチングではレジスト塗布、現像液、レジスト剥離液への浸漬の工程があり、ウェットプロセスで形成した第２電極はダメージを受けやすく、第２電極としての特性を低下させてしまう可能性が非常に高い。これに対して、印刷によるパターニングでは、例えば、スクリーン印刷を用いた場合は版メッシュに起因する表面凹凸、グラビア印刷やスリットダイコートなどを用いた場合は塗り始め、塗り終わりに膜厚段差が発生する可能性が非常に高い。これらの表面粗さや膜厚段差は、これら第２電極の上部に機能層を積層して有機ＥＬ素子を形成した場合には、短絡の要因になる可能性が高い。何れの印刷においても、印刷インクの粘度を低下させることで塗布後のレベリング性を上げて改善できるが、粘度低下に伴い厚膜化が困難になる。ウェットプロセスで形成する電極材料として、一般的によく使用される高導電タイプＰＥＤＯＴ：ＰＳＳなどの導電性高分子材料を用いた場合、膜厚１００～２００ｎｍ程度のＩＴＯなどの透明酸化物導電膜と同等の導電性を得ようとすると、５００～１０００ｎｍ程度の膜厚が必要となる。このため、これら導電性高分子材料を用いた場合、印刷インクの粘度を下げることは難しい。また、導電性の高い材料の場合、比較的薄膜で済むため、印刷インクの粘度も低くて問題ないが、粘度を低くした場合、下地との濡れ性の問題やにじみ等の問題があり、安定的に形成するのは容易ではない。 When the second electrode is formed by a wet process, it is necessary to reduce the surface roughness on the second electrode in order to suppress a short circuit in the organic EL element having a configuration in which the functional layer is formed on the second electrode. In general, since the second electrode portion defines a light emitting area, it is necessary to form a pattern in order to prevent a short circuit with the first electrode. In order to perform such patterning, there are printing patterning methods such as bank formation after film formation, etching, screen printing and the like. Normally, bank formation and etching involve steps of resist coating, developing solution, and immersion in a resist stripping solution, and the second electrode formed by the wet process is easily damaged and may deteriorate the characteristics of the second electrode. The nature is very high. On the other hand, in patterning by printing, for example, when surface printing is used, surface unevenness caused by the plate mesh, when gravure printing or slit die coating is used, a film thickness difference occurs at the start and finish of coating. Very likely. These surface roughness and film thickness step are likely to cause a short circuit when an organic EL element is formed by laminating a functional layer on top of these second electrodes. In any printing, the leveling property after application can be improved by reducing the viscosity of the printing ink, but it becomes difficult to increase the film thickness as the viscosity decreases. When a commonly used conductive polymer material such as high conductivity type PEDOT: PSS is used as an electrode material formed by a wet process, a transparent oxide conductive film such as ITO having a film thickness of about 100 to 200 nm In order to obtain equivalent conductivity, a film thickness of about 500 to 1000 nm is required. For this reason, when using these conductive polymer materials, it is difficult to lower the viscosity of the printing ink. In the case of a highly conductive material, since a relatively thin film is sufficient, the viscosity of the printing ink is low and there is no problem. However, when the viscosity is low, there are problems such as wettability with the base and bleeding, and the stability. It is not easy to form.
　しかし、上述のような有機ＥＬ素子において、図５に示すように、ウェットプロセスで形成された光透過性の第２電極１２上に機能層１６を形成した場合に比べて、図１に示すような通常の素子形成順序とは逆の積層構造にすることにより、短絡の抑制と動作信頼性が向上するとの知見が得られた。特に、フレキシブルな支持基板２１を使用してロールｔｏロールで各層を塗布形成することにより、プロセスコストを低減させることができる。 However, in the organic EL element as described above, as shown in FIG. 5, as shown in FIG. 1, compared to the case where the functional layer 16 is formed on the light-transmissive second electrode 12 formed by the wet process. As a result, it was found that the use of a layered structure opposite to the normal device formation order improves short circuit suppression and operational reliability. In particular, the process cost can be reduced by applying and forming each layer by roll-to-roll using the flexible support substrate 21.
　上記の有機ＥＬ素子は、第１電極２７及び第２電極２２を通じて機能層２６に給電し、この給電により発光層２５で発光させ、この発光を第２電極２２（第２表面２２２）からや、第１電極２７を介した支持基板２１（第１表面２１１）から取り出すことができる。 The organic EL element supplies power to the functional layer 26 through the first electrode 27 and the second electrode 22, causes the light emitting layer 25 to emit light by the power supply, and emits the light from the second electrode 22 (second surface 222). It can be taken out from the support substrate 21 (first surface 211) via the first electrode 27.
　（第２実施形態）
　図２に本発明の第２実施形態を示す。この有機ＥＬ素子は、図１のものにおいて、支持基板２１と第１電極２７との一方が他方を兼ねたものである。その他の構成は、図１と同様である。このように支持基板２１と第１電極２７との一方が他方を兼ねることにより、支持基板２１と第１電極２７とを別々に形成する必要が無く、部品点数を低減することができ、また、第１電極２７のみの形成工程も不要となって、低コスト化を図ることができるものである。図２の例では、支持基板２１にフレキシブルな金属を使用する。この例では、支持基板２１は、バリアフィルムよりも安価で同等の封止性能を有し、かつ第１電極２７を兼ねることができ、これにより大幅なコストダウンを図ることができる。別例において、第１電極２７は支持基板２１を兼ねるように形成される。この場合、第１電極２７は、限定されないが、第１実施形態の厚み（例えばｎｍオーダー）よりも大きな厚み（例えばμｍオーダー）を持つ。 (Second Embodiment)
FIG. 2 shows a second embodiment of the present invention. In the organic EL element shown in FIG. 1, one of the support substrate 21 and the first electrode 27 also serves as the other. Other configurations are the same as those in FIG. As described above, since one of the support substrate 21 and the first electrode 27 also serves as the other, it is not necessary to form the support substrate 21 and the first electrode 27 separately, and the number of parts can be reduced. A process for forming only the first electrode 27 is also unnecessary, and the cost can be reduced. In the example of FIG. 2, a flexible metal is used for the support substrate 21. In this example, the support substrate 21 is cheaper than the barrier film, has the same sealing performance, and can also serve as the first electrode 27, which can greatly reduce the cost. In another example, the first electrode 27 is formed to also serve as the support substrate 21. In this case, the first electrode 27 is not limited, but has a thickness (for example, μm order) larger than the thickness (for example, the nm order) of the first embodiment.
　（第３実施形態）
　図３に本発明の第３実施形態を示す。この有機ＥＬ素子は、図１のものにおいて、第２電極２２をメッシュ状（網状）に形成したものである。その他の構成は図１と同様である。この第２電極２２は上記のような導電性材料で形成することができるが、例えば、銀や銅などの金属材料やカーボンなどの導電性材料を細線材に形成し、複数本の細線材を縦横斜めに適宜クロスさせて形成することができる。細線材の幅のサイズとしては１～１００μｍ程度にすることができるが、これらに限定されるものではない。また、細線材の幅間隔、細線材のアスペクト比についても任意のものを用いることができる。また、これらのメッシュ状の第２電極２２は導電性ペーストをスクリーン印刷などを用いて形成することもできるが、これらに限定されるものではない。 (Third embodiment)
FIG. 3 shows a third embodiment of the present invention. This organic EL element is the same as that shown in FIG. 1 except that the second electrode 22 is formed in a mesh shape. Other configurations are the same as those in FIG. The second electrode 22 can be formed of the above-described conductive material. For example, a metal material such as silver or copper or a conductive material such as carbon is formed on a thin wire, and a plurality of thin wires are formed. It can be formed by crossing appropriately in the vertical and horizontal directions. The width of the thin wire can be about 1 to 100 μm, but is not limited thereto. Moreover, arbitrary things can be used also about the width space | interval of a thin wire material, and the aspect-ratio of a thin wire material. In addition, the mesh-like second electrode 22 can be formed using a conductive paste by screen printing or the like, but is not limited thereto.
　このようなメッシュ状の第２電極２２の網目（開口部）３０の平面視形状は適宜設定可能であり、図３Ｂに示すように、メッシュ状の第２電極２２をグリッド構造（格子構造）として、平面視で四角形の網目３０に形成することができる。また、網目３０は平面視形状で三角形や六角形や円等の任意の形状に形成することができる。 The shape of the mesh (opening) 30 of the mesh-like second electrode 22 in plan view can be set as appropriate. As shown in FIG. 3B, the mesh-like second electrode 22 has a grid structure (lattice structure). In addition, it can be formed in a square mesh 30 in plan view. The mesh 30 can be formed in an arbitrary shape such as a triangle, a hexagon, or a circle in a plan view.
　この第２電極２２は網目３０を通じて機能層２６の発光層２５からの発光を容易に取り出すことができる。そして、この有機ＥＬ素子は、第２電極２２が、導電性透明酸化物により形成された薄膜の場合に比べて、第２電極２２の抵抗率およびシート抵抗を小さくすることが可能となり、第２電極２２の低抵抗化により輝度むらを低減することが可能となる。 The second electrode 22 can easily take out light emitted from the light emitting layer 25 of the functional layer 26 through the mesh 30. This organic EL element can reduce the resistivity and sheet resistance of the second electrode 22 as compared with the case where the second electrode 22 is a thin film formed of a conductive transparent oxide. It is possible to reduce luminance unevenness by reducing the resistance of the electrode 22.
　（第４実施形態）
　図４に本発明の第４実施形態を示す。この有機ＥＬ素子は、図３のものにおいて、第２実施形態と同様に、支持基板２１と第１電極２７との一方が他方を兼ねたものである。その他の構成は、図３と同様である。 (Fourth embodiment)
FIG. 4 shows a fourth embodiment of the present invention. In the organic EL element shown in FIG. 3, one of the support substrate 21 and the first electrode 27 also serves as the other, as in the second embodiment. Other configurations are the same as those in FIG.
　以下、本発明を実施例によって具体的に説明する。 Hereinafter, the present invention will be specifically described by way of examples.
　（実施例１）
　支持基板を用意し、非ウェットプロセス（ドライプロセス）により支持基板（第２表面）に第１電極を形成した。実施例１では、支持基板として厚み０．７ｍｍの無アルカリガラス板（Ｎｏ．１７３７、コーニング製）を用いた。次いで、真空蒸着法により、支持基板上にアルミニウムを８０ｎｍの厚みで成膜して第１電極（陰極）を形成した。 Example 1
A support substrate was prepared, and a first electrode was formed on the support substrate (second surface) by a non-wet process (dry process). In Example 1, a non-alkali glass plate (No. 1737, manufactured by Corning) having a thickness of 0.7 mm was used as the support substrate. Next, a first electrode (cathode) was formed by vacuum deposition of aluminum on the support substrate to a thickness of 80 nm.
　次に、ウェットプロセスにより、第１電極（第２表面）に機能層を形成した。実施例１では、赤色高分子（アメリカンダイソース社製「Ｌｉｇｈｔ　Ｅｍｉｔｔｉｎｇ　ｐｏｌｙｍｅｒ　ＡＴＳ１１１ＲＥ」）をＴＨＦ溶媒に１ｗｔ％になるよう溶解した溶液（以下「第１溶液」という）を用意し、第１溶液を第１電極（陰極）上に膜厚が約２００ｎｍになるようにスピンコーターで塗布し、それを１００℃で１０分間焼成することによって発光層を形成した。次に、ＴＦＢ（Ｐｏｌｙ［（９，９－ｄｉｏｃｔｙｌｆｌｕｏｒｅｎｙｌ－２，７－ｄｉｙｌ）－ｃｏ－（４，４’－（Ｎ－（４－ｓｅｃ－ｂｕｔｙｌｐｈｅｎｙｌ））ｄｉｐｈｅｎｙｌ　ａｍｉｎｅ）］）（アメリカンダイソース社製「Ｈｏｌｅ　Ｔｒａｎｓｐｏｒｔ　Ｐｏｌｙｍｅｒ　ＡＤＳ２５９ＢＥ」）をＴＨＦ溶媒に１ｗｔ％になるよう溶解した溶液（以下「第２溶液」という）を用意し、第２溶液を発光層の上に膜厚が約１２ｎｍになるようにスピンコーターで塗布してＴＦＢ被膜を作製し、これを２００℃で１０分間焼成することによって、ホール輸送層を形成した。次に、ポリエチレンジオキシチオフェン／ポリスチレンスルホン酸（ＰＥＤＯＴ－ＰＳＳ）（スタルクヴィテック社製「Ｂａｙｔｒｏｎ　Ｐ　ＡＩ４０８３」、ＰＥＤＯＴ：ＰＳＳ＝１：６）とイソプロピルアルコールを１：１で混合した溶液（以下「第３溶液」という）を用意し、第３溶液をホール輸送層上にＰＥＤＯＴ－ＰＳＳの膜厚が３０ｎｍになるようにスピンコーターで塗布し、それを１５０℃で１０分間焼成することにより、ホール注入層を形成した。 Next, a functional layer was formed on the first electrode (second surface) by a wet process. In Example 1, a red polymer (“Light Emitting Polymer ATS111RE” manufactured by American Dye Source Co.) was dissolved in THF solvent to 1 wt% (hereinafter referred to as “first solution”), and the first solution was prepared. A light-emitting layer was formed by coating the first electrode (cathode) with a spin coater so as to have a film thickness of about 200 nm and baking it at 100 ° C. for 10 minutes. Next, TFB (Poly [(9,9-dioctylfluorenyl-2,7-diyl) -co- (4,4 ′-(N- (4-sec-butylphenyl))) diphenyl amine)] (American Dye Source) A solution (hereinafter referred to as “second solution”) prepared by dissolving “Hole Transport Polymer ADS259BE”) in THF solvent to 1 wt% is prepared, and the second solution is formed on the light emitting layer so that the film thickness is about 12 nm. A TFB film was prepared by coating with a spin coater and baked at 200 ° C. for 10 minutes to form a hole transport layer. Next, a solution prepared by mixing polyethylene dioxythiophene / polystyrene sulfonic acid (PEDOT-PSS) (“Baytron P AI4083, PEDOT: PSS = 1: 6” manufactured by Starck Vitec Co., Ltd.) and isopropyl alcohol 1: 1 (hereinafter “ The third solution ”is prepared), and the third solution is applied onto the hole transport layer with a spin coater so that the film thickness of PEDOT-PSS is 30 nm, and is baked at 150 ° C. for 10 minutes. An injection layer was formed.
　さらに、ウェットプロセスにより、機能層（第２表面）に第２電極を形成した。実施例１では、ＩＴＯナノ粒子（粒子径約４０ｎｍ、シーアイ化成社製　ＮａｎｏＴｅｋ（登録商標）ＩＴＣＷ１５ｗｔ％－Ｇ３０）にメチルセルロース（信越化学社製ＭＥＴＯＬＯＳＥ（登録商標）６０ＳＨ）を５ｗｔ％混合した溶液（以下「第４溶液」という）を用意し、第４溶液をインクとしてスクリーン印刷機を通じてホール注入層上に膜厚が３００ｎｍ程度になるように印刷してパターンを形成し、それを１２０℃１５分間乾燥することにより第２電極（陽極）を形成した。これにより、図１のような層構成の有機ＥＬ素子を得た。 Furthermore, a second electrode was formed on the functional layer (second surface) by a wet process. In Example 1, ITO nanoparticle (particle size: about 40 nm, NanoTek (registered trademark) ITCW 15 wt% -G30 manufactured by CI Kasei Co., Ltd.) and methyl cellulose (METOLOSE (registered trademark) 60SH manufactured by Shin-Etsu Chemical Co., Ltd.) 5 wt% mixed (hereinafter referred to as “solution”). "Fourth solution") is prepared, and the fourth solution is printed as an ink on a hole injection layer through a screen printer so that the film thickness is about 300 nm to form a pattern, which is dried at 120 ° C for 15 minutes. Thus, a second electrode (anode) was formed. As a result, an organic EL element having a layer structure as shown in FIG. 1 was obtained.
　（実施例２）
　第１電極を兼ねる支持基板を用意し、ウェットプロセスにより支持基板（第２表面）に機能層を形成し、そしてウェットプロセスにより機能層（第２表面）に第２電極を形成した。実施例２では、支持基板としてアルミ箔（約３０μｍ厚）を用い、この支持基板を第１電極として兼用した。また、支持基板の平滑面（第２表面）側に発光層を実施例１と同一の方法で形成した以外は、実施例１と同様にして図２のような層構成の有機ＥＬ素子を得た。 (Example 2)
A support substrate also serving as a first electrode was prepared, a functional layer was formed on the support substrate (second surface) by a wet process, and a second electrode was formed on the functional layer (second surface) by a wet process. In Example 2, an aluminum foil (about 30 μm thick) was used as the support substrate, and this support substrate was also used as the first electrode. Further, an organic EL element having a layer structure as shown in FIG. 2 was obtained in the same manner as in Example 1 except that the light emitting layer was formed on the smooth surface (second surface) side of the support substrate by the same method as in Example 1. It was.
　（実施例３）
　ホール注入層上に高導電性のポリエチレンジオキシチオフェン／ポリスチレンスルホン酸（ＰＥＤＯＴ－ＰＳＳ）を塗布して約２００ｎｍの高導電ポリマー層を形成した。さらにその表面に印刷用銀ペースト材料を用いて、図３Ａ及び３Ｂに示すようなメッシュ状の第２電極を陽極としてスクリーン印刷で形成した。線幅は約４０μｍ、線中心間ピッチは約１０００μｍ、メッシュ高さは約５μｍであった。それ以外は、実施例１と同様にして図３Ａのような層構成の有機ＥＬ素子を得た。 (Example 3)
Highly conductive polyethylene dioxythiophene / polystyrene sulfonic acid (PEDOT-PSS) was applied on the hole injection layer to form a highly conductive polymer layer of about 200 nm. Further, using a silver paste material for printing on the surface, a mesh-like second electrode as shown in FIGS. 3A and 3B was formed by screen printing as an anode. The line width was about 40 μm, the pitch between line centers was about 1000 μm, and the mesh height was about 5 μm. Other than that was carried out similarly to Example 1, and obtained the organic EL element of a layer structure like FIG. 3A.
　（実施例４）
　ホール注入層上に高導電性のポリエチレンジオキシチオフェン／ポリスチレンスルホン酸（ＰＥＤＯＴ－ＰＳＳ）を塗布して約２００ｎｍの高導電ポリマー層を形成した。さらにその表面に印刷用銀ペースト材料を用いて、図４に示すようなメッシュ状の第２電極を陽極としてスクリーン印刷で形成した。線幅は約４０μｍ、線中心間ピッチは約１０００μｍ、メッシュ高さは約５μｍであった。それ以外は、実施例２と同様にして図４のような層構成の有機ＥＬ素子を得た。 Example 4
Highly conductive polyethylene dioxythiophene / polystyrene sulfonic acid (PEDOT-PSS) was applied on the hole injection layer to form a highly conductive polymer layer of about 200 nm. Further, a silver paste material for printing was used on the surface, and a mesh-like second electrode as shown in FIG. 4 was formed by screen printing as an anode. The line width was about 40 μm, the pitch between line centers was about 1000 μm, and the mesh height was about 5 μm. Other than that was carried out similarly to Example 2, and obtained the organic EL element of a layer structure like FIG.
　（比較例１）
　支持基板として厚み０．７ｍｍの無アルカリガラス板（Ｎｏ．１７３７、コーニング製）を用いた。ＩＴＯナノ粒子（粒子径約４０ｎｍ、シーアイ化成社製　ＮａｎｏＴｅｋ（登録商標）ＩＴＣＷ１５ｗｔ％－Ｇ３０）にメチルセルロース（信越化学社製ＭＥＴＯＬＯＳＥ（登録商標）６０ＳＨ）を５ｗｔ％混合した溶液を用意し、その溶液をスクリーン印刷機を通じて支持基板上に膜厚が３００ｎｍ程度になるように印刷してパターンを形成し、それを１２０℃１５分間乾燥することにより第２電極（陽極）を形成した。次に、ポリエチレンジオキシチオフェン／ポリスチレンスルホン酸（ＰＥＤＯＴ－ＰＳＳ）（スタルクヴィテック社製「Ｂａｙｔｒｏｎ　Ｐ　ＡＩ４０８３」、ＰＥＤＯＴ：ＰＳＳ＝１：６）とイソプロピルアルコールを１：１で混合した溶液を用意し、その溶液を第２電極（陽極）上にＰＥＤＯＴ－ＰＳＳの膜厚が３０ｎｍになるようにスピンコーターで塗布し、それを１５０℃で１０分間焼成することにより、ホール注入層を形成した。さらに、ＴＦＢ（Ｐｏｌｙ［（９，９－ｄｉｏｃｔｙｌｆｌｕｏｒｅｎｙｌ－２，７－ｄｉｙｌ）－ｃｏ－（４，４’－（Ｎ－（４－ｓｅｃ－ｂｕｔｙｌｐｈｅｎｙｌ））ｄｉｐｈｅｎｙｌ　ａｍｉｎｅ）］）（アメリカンダイソース社製「Ｈｏｌｅ　Ｔｒａｎｓｐｏｒｔ　Ｐｏｌｙｍｅｒ　ＡＤＳ２５９ＢＥ」）をＴＨＦ溶媒に１ｗｔ％になるよう溶解した溶液を用意し、その溶液をホール注入層の上に膜厚が約１２ｎｍになるようにスピンコーターで塗布してＴＦＢ被膜を作製し、これを２００℃で１０分間焼成することによって、ホール輸送層を形成した。次に、赤色高分子（アメリカンダイソース社製「Ｌｉｇｈｔ　Ｅｍｉｔｔｉｎｇ　ｐｏｌｙｍｅｒ　ＡＴＳ１１１ＲＥ」）をＴＨＦ溶媒に１ｗｔ％になるよう溶解した溶液を用意し、その溶液をホール輸送層上に膜厚が約２００ｎｍになるようにスピンコーターで塗布し、それを１００℃で１０分間焼成することによって発光層を形成した。最後に真空蒸着法により、支持基板上にアルミニウムを８０ｎｍの厚みで成膜して第１電極（陰極）を形成することで、有機ＥＬ素子を得た。 (Comparative Example 1)
A non-alkali glass plate (No. 1737, manufactured by Corning) having a thickness of 0.7 mm was used as the support substrate. Prepare a solution of ITO nanoparticles (particle diameter of about 40 nm, NanoTek (registered trademark) ITCW 15 wt% -G30 manufactured by C-I Kasei Co., Ltd.) and 5 wt% of methylcellulose (METOLOSE (registered trademark) 60SH manufactured by Shin-Etsu Chemical Co., Ltd.). A pattern was formed by printing on a support substrate through a screen printer so that the film thickness was about 300 nm, and this was dried at 120 ° C. for 15 minutes to form a second electrode (anode). Next, a solution in which polyethylene dioxythiophene / polystyrene sulfonic acid (PEDOT-PSS) (“Baytron P AI4083” manufactured by Starck Vitech, PEDOT: PSS = 1: 6) and isopropyl alcohol are mixed at 1: 1 is prepared. Then, the solution was applied onto the second electrode (anode) with a spin coater so that the film thickness of PEDOT-PSS was 30 nm, and baked at 150 ° C. for 10 minutes to form a hole injection layer. Furthermore, TFB (Poly [(9,9-dioctylfluorenyl-2,7-diyl) -co- (4,4 ′-(N- (4-sec-butyphenyl))) diphenyl amine)] (manufactured by American Dye Source) “Hole Transport Polymer ADS259BE”) is prepared in a THF solvent so as to be 1 wt%, and the solution is applied onto the hole injection layer with a spin coater so that the film thickness is about 12 nm. The hole transport layer was formed by producing and baking this at 200 ° C. for 10 minutes. Next, a solution in which a red polymer (“Light Emitting Polymer ATS111RE” manufactured by American Dye Source Co., Ltd.) is dissolved to 1 wt% in a THF solvent is prepared, and the film thickness is about 200 nm on the hole transport layer. Thus, the light emitting layer was formed by applying with a spin coater and baking it at 100 ° C. for 10 minutes. Finally, an organic EL element was obtained by forming a first electrode (cathode) by depositing aluminum with a thickness of 80 nm on a support substrate by vacuum deposition.
　（比較例２）
　支持基板としてアルミ箔（約３０μｍ厚）を用いて、支持基板の平滑面側に発光層を比較例１と同一の方法で形成した以外は、比較例１と同様にして有機ＥＬ素子を得た。すなわち、比較例１では、支持基板の平滑面上に、第２電極（陽極）、ホール注入層、ホール輸送層、発光層及び第１電極（陰極）が順に形成されるが、比較例２では、支持基板の平滑面上に、第２電極（陰極）、発光層、ホール輸送層、ホール注入層及び第１電極（陽極）が順に形成される。 (Comparative Example 2)
An organic EL device was obtained in the same manner as in Comparative Example 1 except that an aluminum foil (about 30 μm thick) was used as the support substrate and the light emitting layer was formed on the smooth surface side of the support substrate by the same method as in Comparative Example 1. . That is, in Comparative Example 1, the second electrode (anode), the hole injection layer, the hole transport layer, the light emitting layer, and the first electrode (cathode) are sequentially formed on the smooth surface of the support substrate. The second electrode (cathode), the light emitting layer, the hole transport layer, the hole injection layer, and the first electrode (anode) are sequentially formed on the smooth surface of the support substrate.
　各実施例および比較例にて得られた有機ＥＬ素子において、電極間に電流密度が１０ｍＡ／ｃｍ2となるように電流を流し、正面輝度を輝度計（トプコンテクノハウス社製ＢＭ－７Ａ）により計測した。実施例１（図１）－４（図４）の正面は、それぞれ、それら第２電極（２２）の第２表面（２２２）であり、比較例１及び２の正面は、それぞれ、支持基板の表面（第２電極とは反対の支持基板の面）である。 In the organic EL devices obtained in the examples and comparative examples, a current was passed between the electrodes so that the current density was 10 mA / cm 2, and the front luminance was measured with a luminance meter (BM-7A manufactured by Topcon Technohouse). Measured. The front surfaces of Example 1 (FIG. 1) -4 (FIG. 4) are the second surfaces (222) of the second electrodes (22), respectively, and the front surfaces of Comparative Examples 1 and 2 are the support substrates, respectively. It is the surface (the surface of the support substrate opposite to the second electrode).
　表１において、比較例１の正面輝度を１としたときの各正面輝度の相対値を示す。 In Table 1, the relative value of each front luminance when the front luminance of Comparative Example 1 is set to 1 is shown.
　表１に見られるように、正面輝度については実施例１～４は比較例１と同等であるが、駆動電圧については比較例１は実施例１～４に比べて増大している。さらに、金属箔上に順に積層構造を形成した比較例２については発光を確認することができなかった。従って、図１に示すような通常の素子形成順序とは逆の積層構造にすることにより、ウェットプロセスで形成された光透過性の陽極（第２電極）上に機能層（有機層）を形成した場合に生じやすい短絡の抑制が確認できる。また実施例２、４の結果から、基板として金属箔を用いた場合、金属箔が陰極を兼ねたとしても、特性の低下はみられないことが確認できる。 As can be seen from Table 1, the front luminance of Examples 1 to 4 is equivalent to that of Comparative Example 1, but the driving voltage of Comparative Example 1 is higher than that of Examples 1 to 4. Furthermore, light emission was not able to be confirmed about the comparative example 2 which formed the laminated structure in order on the metal foil. Therefore, a functional layer (organic layer) is formed on a light-transmitting anode (second electrode) formed by a wet process by using a layered structure reverse to the normal element formation order as shown in FIG. It is possible to confirm the suppression of short circuits that are likely to occur when Further, from the results of Examples 2 and 4, it can be confirmed that when the metal foil is used as the substrate, no deterioration in the characteristics is observed even if the metal foil also serves as the cathode.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　本発明を幾つかの好ましい実施形態について記述したが、この発明の本来の精神および範囲、即ち請求の範囲を逸脱することなく、当業者によって様々な修正および変形が可能である。 While the invention has been described in terms of several preferred embodiments, various modifications and variations can be made by those skilled in the art without departing from the true spirit and scope of the invention, ie, the claims.

Claims (9)

  1. 　少なくとも発光層を含む機能層を第１電極に積層形成した後、前記機能層に第２電極を積層形成することを含む有機エレクトロルミネッセンス素子の製造方法であって、
    　ウェットプロセスにより前記第２電極を形成することを含み、前記第２電極は光透過性を有することを特徴とする有機エレクトロルミネッセンス素子の製造方法。     A method for producing an organic electroluminescence device, comprising: laminating and forming a functional layer including at least a light emitting layer on a first electrode, and then laminating and forming a second electrode on the functional layer,
    Forming the second electrode by a wet process, wherein the second electrode is light-transmissive.
  2. 　ドライプロセスにより前記第１電極を形成することを含むことを特徴とする請求項１に記載の有機エレクトロルミネッセンス素子の製造方法。 The method of manufacturing an organic electroluminescence element according to claim 1, further comprising forming the first electrode by a dry process.
  3. 　ドライプロセスにより支持基板に前記第１電極を形成すること、
    　ウェットプロセスにより前記第１電極に前記機能層を形成すること、及び
    　ウェットプロセスにより前記機能層に前記第２電極を形成すること
    を含むことを特徴とする請求項１又は２に記載の有機エレクトロルミネッセンス素子の製造方法。     Forming the first electrode on a support substrate by a dry process;
    The organic electroluminescence according to claim 1, further comprising: forming the functional layer on the first electrode by a wet process; and forming the second electrode on the functional layer by a wet process. Device manufacturing method.
  4. 　支持基板と第１電極との一方が他方を兼ねることを特徴とする請求項１又は２に記載の有機エレクトロルミネッセンス素子の製造方法。 3. The method of manufacturing an organic electroluminescence element according to claim 1, wherein one of the support substrate and the first electrode also serves as the other.
  5. 　ウェットプロセスにより前記第１電極を兼ねる支持基板に前記機能層を形成すること、及び
    　ウェットプロセスにより前記機能層に前記第２電極を形成すること
    を含むことを特徴とする請求項１又は２に記載の有機エレクトロルミネッセンス素子の製造方法。     3. The method according to claim 1, further comprising: forming the functional layer on a support substrate that also serves as the first electrode by a wet process; and forming the second electrode on the functional layer by a wet process. The manufacturing method of organic electroluminescent element of this.
  6. 　前記第２電極をメッシュ状に形成することを含むことを特徴とする請求項１から５の何れか１項に記載の有機エレクトロルミネッセンス素子の製造方法。 The method for producing an organic electroluminescent element according to any one of claims 1 to 5, further comprising forming the second electrode in a mesh shape.
  7. 　第１電極に積層形成される少なくとも発光層を含む機能層と、この機能層に積層形成される第２電極とを備えた有機エレクトロルミネッセンス素子であって、前記第１電極の機能層と反対側に支持基板を備え、前記第２電極は光透過性を有して成ることを特徴とする有機エレクトロルミネッセンス素子。 An organic electroluminescence device comprising a functional layer including at least a light emitting layer formed on a first electrode and a second electrode formed on the functional layer, the organic electroluminescence element being opposite to the functional layer of the first electrode An organic electroluminescence device comprising: a support substrate; and the second electrode having optical transparency.
  8. 　第１電極に積層形成される発光層を含む機能層と、この機能層に積層形成される第２電極とを備えた有機エレクトロルミネッセンス素子であって、前記第１電極は支持基板として形成され、前記第２電極は光透過性を有して成ることを特徴とする有機エレクトロルミネッセンス素子。 An organic electroluminescence device comprising a functional layer including a light emitting layer laminated on a first electrode and a second electrode laminated on the functional layer, wherein the first electrode is formed as a support substrate, 2. The organic electroluminescence device according to claim 1, wherein the second electrode is light transmissive.
  9. 　前記第２電極がメッシュ状に形成されていることを特徴とする請求項７又は８に記載の有機エレクトロルミネッセンス素子。 The organic electroluminescence element according to claim 7 or 8, wherein the second electrode is formed in a mesh shape.
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11224782A (en) * 1998-02-06 1999-08-17 Kawaguchiko Seimitsu Kk Electroluminescence
JP2002352962A (en) * 2001-05-28 2002-12-06 Matsushita Electric Ind Co Ltd Organic light-emitting element and manufacturing method therefor, organic light-emitting display device, and the illumination device
JP2006216561A (en) * 2005-02-05 2006-08-17 Samsung Sdi Co Ltd Organic light-emitting device and white light emitting device
JP2006286542A (en) * 2005-04-04 2006-10-19 Ehc:Kk Material for cathode of organic electroluminescent element, organic electroluminescent element and its manufacturing method
JP2009152113A (en) * 2007-12-21 2009-07-09 Rohm Co Ltd Organic el element
JP2009301965A (en) * 2008-06-17 2009-12-24 Hitachi Ltd Organic light-emitting device
JP2011003442A (en) * 2009-06-19 2011-01-06 Saitama Univ Method of manufacturing organic thin film element

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11224782A (en) * 1998-02-06 1999-08-17 Kawaguchiko Seimitsu Kk Electroluminescence
JP2002352962A (en) * 2001-05-28 2002-12-06 Matsushita Electric Ind Co Ltd Organic light-emitting element and manufacturing method therefor, organic light-emitting display device, and the illumination device
JP2006216561A (en) * 2005-02-05 2006-08-17 Samsung Sdi Co Ltd Organic light-emitting device and white light emitting device
JP2006286542A (en) * 2005-04-04 2006-10-19 Ehc:Kk Material for cathode of organic electroluminescent element, organic electroluminescent element and its manufacturing method
JP2009152113A (en) * 2007-12-21 2009-07-09 Rohm Co Ltd Organic el element
JP2009301965A (en) * 2008-06-17 2009-12-24 Hitachi Ltd Organic light-emitting device
JP2011003442A (en) * 2009-06-19 2011-01-06 Saitama Univ Method of manufacturing organic thin film element

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