Top emission el light-emitting device and method for manufacturing same

Abstract

Provided is a top emission EL light-emitting device comprising: an EL element in which a first electrode, an emissive layer (EML), and a transparent second electrode are laminated; and an auxiliary electrode. The first electrode and the emissive layer (EML) are formed on one side of the second electrode. The auxiliary electrode is disposed at a position different from the EL element on the one side of the second electrode. A contact part is interposed between the auxiliary electrode and the second electrode, and the contact part includes particles.

Description

Top-emission EL light-emitting device and its manufacturing method

[0001] The present invention relates to a top-emission EL (Electroluminescence) light-emitting device and a method for manufacturing the same.

[0002] In top-emission EL light-emitting devices, an oxide-based transparent conductive film, such as indium tin oxide (ITO), or an extremely thin metal film transparent electrode of 10 nm or less is disposed as the upper electrode. These transparent electrodes have higher electrical resistance than common wiring materials, resulting in a voltage drop according to the distance from the peripheral power supply line, and a corresponding brightness gradient. To solve this problem, auxiliary wiring is generally stacked on the transparent electrode so as to avoid the pixels.

[0003] Special Publication No. 2023-540317

[0004] The present invention proposes a configuration and method for filling an auxiliary electrode via of an auxiliary electrode contact with conductive particles having an uneven shape, thereby electrically connecting the auxiliary wiring and the upper electrode.

[0005] One aspect of the present invention is a top-emission type EL light-emitting device having an EL element in which a first electrode, an emissive layer (EML), and a transparent second electrode are stacked, and an auxiliary electrode, wherein the first electrode and the emissive layer (EML) are formed on one side of the second electrode, and the auxiliary electrode is disposed on the one side of the second electrode at a position different from the EL element, and a contact portion is interposed between the auxiliary electrode and the second electrode, and the contact portion contains particles.

[0006] Another aspect of the present invention is a method for manufacturing the above-mentioned top-emission type EL light-emitting device, which has an auxiliary electrode contact that connects the auxiliary electrode and the second electrode, and the process for forming the auxiliary electrode contact includes the steps of forming an auxiliary electrode, arranging particles on the auxiliary electrode, forming an EL layer on the auxiliary electrode with the particles arranged on it, and forming the second electrode on the EL layer.

[0007] 1 is a schematic cross-sectional view showing a top-emission type EL light-emitting device 1 according to the present embodiment. FIG. 2 is a schematic cross-sectional view showing a top-emission type EL light-emitting device 2 according to the present embodiment. FIG. 3 is a schematic cross-sectional view showing a top-emission type EL light-emitting device 3 according to the present embodiment. FIG. 4 is a schematic diagram showing an image of forming an EL layer on particles P in the top-emission type EL light-emitting device 1 according to the present embodiment. FIG. 5 is a schematic diagram showing an image of conduction between the second electrode 106 and the auxiliary electrode 12 in the top-emission type EL light-emitting device 1 according to the present embodiment. FIG. 6 is a block diagram showing a method for manufacturing the top-emission type EL light-emitting device 1 according to the present embodiment. FIG. 7 is a block diagram showing a method for manufacturing the top-emission type EL light-emitting device 2 according to the present embodiment. FIG. 8 is a block diagram showing a method for manufacturing the top-emission type EL light-emitting device 3 according to the present embodiment. FIG. 9 is a diagram showing a step profile of a bank opening (blank) in which no particles are arranged in Comparative Example 1. FIG. 10 is a diagram showing a step profile of a bank opening in which ITO particles are arranged in Example 1. FIG. 11 is a diagram showing a step profile of a bank opening in which carbon nanohorns are arranged in Example 2. FIG. 12 is a diagram showing a step profile of a bank opening in which Ag particles having a total particle film thickness of 235 nm are arranged in Example 3. 1 is a diagram showing a step profile of a bank opening in which Ag particles having a total particle thickness of 350 nm are arranged in Example 4. FIG. 2 is a diagram showing a step profile of a bank opening in which Ag particles having a total particle thickness of 430 nm are arranged in Example 5. FIG. 3 is a graph showing current density versus applied voltage to an EL element in which no particles are arranged in Comparative Example 1. FIG. 4 is a graph showing current density versus applied voltage to an EL element in which ITO particles are arranged in Example 1. FIG. 5 is a graph showing current density versus applied voltage to an EL element in which carbon nanohorns are arranged in Example 2. FIG. 6 is a graph showing current density versus applied voltage to an EL element in which Ag particles having a total particle thickness of 235 nm are arranged in Example 3. FIG. 7 is a graph showing current density versus applied voltage to an EL element in which Ag particles having a total particle thickness of 350 nm are arranged in Example 4. FIG. 8 is a graph showing current density versus applied voltage to an EL element in which Ag particles having a total particle thickness of 430 nm are arranged in Example 5.

[0008] An embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described below. The present embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following content. The present invention can be practiced with appropriate modifications within the scope of its gist.

[0009] <Top-Emission EL Light-Emitting Device> Figures 1 to 3 show a top-emission EL light-emitting device according to this embodiment. Figures 1 to 3 show EL elements (11, 21, 31) and auxiliary electrode contacts (10, 20, 30). An active matrix substrate is provided below the BP wiring (101a, 201a, 301a), planarization film (102, 202, 302), and auxiliary electrode wiring (101b, 201b, 301b), but is omitted from Figures 1 to 3. The top-emission EL light-emitting device according to this embodiment can have a structure such as that shown in Figures 1 to 3, for example. The top-emission EL light-emitting device 1 in Figure 1 has an inverted structure in which an electron injection layer (EIL) / electron transport layer (ETL) are formed by sputtering. 2 has an inverted structure similar to that of FIG. 1, in which an electron injection layer EIL / electron transport layer ETL are formed by coating. Furthermore, a top-emission EL light-emitting device 3 of FIG. 3 has a forward structure different from that of FIGS. 1 and 2, in which a hole injection layer HIL (hole injection layer) / hole transport layer HTL (hole transport layer) are formed by coating. Although not shown in the figure, the top-emission EL light-emitting device according to this embodiment may have a forward structure in which the hole injection layer HIL / hole transport layer HTL are formed by sputtering.

[0010] The top-emission type EL light-emitting device according to this embodiment will be specifically described with reference to Figures 1 to 3. The three reference numerals in parentheses attached to the respective components correspond to Figures 1, 2, and 3, respectively.

[0011] The top-emission EL light-emitting devices 1 to 3 according to the present embodiment each include an EL element (11, 21, 31) and an auxiliary electrode contact (10, 20, 30). The EL element (11, 21, 31) includes a first electrode (104, 204, 304), an electron injection layer EIL, an electron transport layer ETL, an emitting layer EML, a hole transport layer HTL, a hole injection layer HIL, and a transparent second electrode (106, 206, 306), which are stacked one on the other. The electron injection layer EIL, the electron transport layer ETL, the emitting layer EML, the hole transport layer HTL, and the hole injection layer HIL are collectively referred to as the EL layer. The EL layer between the first electrode and the second electrode may include at least the emitting layer EML, and may additionally include either the electron injection layer EIL or the electron transport layer ETL, or either the hole injection layer HIL or the hole transport layer HTL. The first electrodes (104, 204, 304) and the EL layer are formed on one side (below) of the second electrodes (106, 206, 306). Since the EL light-emitting devices 1 to 3 are top-emission type, the second electrodes (106, 206, 306) are transparent electrodes.

[0012] At the auxiliary electrode contacts (10, 20, 30), the second electrodes (106, 206, 306) are electrically connected to the auxiliary electrodes (12, 22, 32). At the auxiliary electrode contacts (10, 20, 30), the second electrodes (106, 206, 306), which have high electrical resistance, are electrically connected to the auxiliary electrodes (12, 22, 32), thereby reducing the electrical resistance of the second electrodes (106, 206, 306).

[0013] The first electrode (104, 204, 304) is a reflective electrode, and functions as a cathode in FIGS. 1 and 2 and as an anode in FIG. 3. The material of the first electrode is not particularly limited, and known materials can be used. Specific examples include single layers of Mo, W, Al, Cu, Au, Cu-Al alloy, Al-Si alloy, Mo-W alloy, Ni-P alloy, etc., and laminates thereof. The thickness of the first electrode (104, 204, 304) is 10 nm or more and 1000 nm or less.

[0014] The second electrode (106, 206, 306) is a transparent electrode, and functions as an anode in FIGS. 1 and 2, and as a cathode in FIG. 3. The material of the second electrode is not particularly limited, and known materials can be used. Specific examples include single layers of ITO (indium tin oxide), Mo, W, Al, Cu, Au, Cu-Al alloy, Al-Si alloy, Mo-W alloy, Ni-P alloy, etc., and laminates thereof. The thickness of the second electrode (106, 206, 306) is 1 nm or more and 3000 nm or less.

[0015] The emitting layer EML is an EL layer, and is painted with red, green, and blue inks. The material of the emitting layer EML may be any material that can be commonly used, or a mixture of these materials may be used. Specifically, for example, the emitting layer EML may be made of bis[2-(2-benzothiazolyl)phenolato]zinc(II) (Zn(BTZ) ２ ) and tris[1-phenylisoquinoline]iridium(III) (Ir(piq) ３ ) The material forming the emitting layer EML may be a low molecular weight compound or a high molecular weight compound. In the present invention, the low molecular weight material means a material that is not a high molecular weight material (polymer), and does not necessarily mean an organic compound with a low molecular weight.

[0016] Examples of polymer materials for forming the light-emitting layer EML include polyacetylene compounds such as trans-polyacetylene, cis-polyacetylene, poly(diphenylacetylene) (PDPA), and poly(alkylphenylacetylene) (PAPA); poly(para-phenvinylene) (PPV), poly(2,5-dialkoxy-para-phenylenevinylene) (RO-PPV), and cyano-substituted-poly(para-phenvinylene) (CN-PP). polyparaphenylene vinylene compounds such as poly(2-dimethyloctylsilyl-para-phenylene vinylene) (DMOS-PPV) and poly(2-methoxy,5-(2'-ethylhexoxy)-para-phenylene vinylene) (MEH-PPV); polythiophene compounds such as poly(3-alkylthiophene) (PAT) and poly(oxypropylene) triol (POPT); poly(9,9-dialkylfluorene) (P polyfluorene-based compounds such as poly(dioctylfluorene-alt-benzothiadiazole) (F8BT), α,ω-bis[N,N'-di(methylphenyl)aminophenyl]-poly[9,9-bis(2-ethylhexyl)fluorene-2,7-dyl] (PF2 / 6am4), poly(9,9-dioctyl-2,7-divinylenefluorenyl-ortho-co(anthracene-9,10-diyl); poly(para-phenylene) Examples of suitable polymeric materials include polyparaphenylene compounds such as poly(N-vinylcarbazole) (PVK), poly(1,5-dialkoxy-para-phenylene) (PPP), and poly(1,5-dialkoxy-para-phenylene) (RO-PPP); polycarbazole compounds such as poly(N-vinylcarbazole) (PVK); polysilane compounds such as poly(methylphenylsilane) (PMPS), poly(naphthylphenylsilane) (PNPS), and poly(biphenylylphenylsilane) (PBPS); and boron compound polymeric materials.

[0017] Examples of low molecular weight materials for forming the light emitting layer EML include a three-coordinate iridium complex having 2,2'-bipyridine-4,4'-dicarboxylic acid as a ligand, and factotris(2-phenylpyridine)iridium (Ir(ppy) ３ ), fac-tris(3-methyl-2-phenylpyridinato-N,C2′-)iridium(III) (Ir(mppy) ３), 8-hydroxyquinoline aluminum (Alq ３ ), tris(4-methyl-8-quinolinolato)aluminum(III) (Almq ３ ), 8-hydroxyquinoline zinc (Znq ２ ), (1,10-phenanthroline)-tris-(4,4,4-trifluoro-1-(2-thienyl)-butane-1,3-dionate) europium(III) (Eu(TTA) ３(phen)), various metal complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine platinum(II); benzene-based compounds such as distyrylbenzene (DSB) and diaminodistyrylbenzene (DADSB); naphthalene-based compounds such as naphthalene and Nile Red; phenanthrene-based compounds such as phenanthrene; chrysene-based compounds such as chrysene and 6-nitrochrysene; perylene, N,N'-bis(2,5-di-t-butylphenyl)-3,4,9,10-perylene-di-carboximide ( perylene-based compounds such as bis(4-(9H-carbazol-9-yl)-2,6-dimethylphenyl)-9,10-diboraanthracene (CzDBA) represented by the formula (31) described below; pyrene-based compounds such as pyrene; pyran-based compounds such as 4-(di-cyanomethylene)-2-methyl-6-(para-dimethylaminostyryl)-4H-pyran (DCM); acridine-based compounds such as acridine; stilbene-based compounds such as bis(4-(9H-carbazol-9-yl)-2,6-dimethylphenyl)-9,10-diboraanthracene (CzDBA); thiophene-based compounds such as 2,5-dibenzoxazolethiophene; benzoxazole-based compounds such as benzoxazole; benzimidazole-based compounds such as benzimidazole; benzothiazole-based compounds such as 2,2'-(para-phenylenedivinylene)-bisbenzothiazole; butadiene-based compounds such as bistyryl(1,4-diphenyl-1,3-butadiene) and tetraphenylbutadiene; naphthalimide-based compounds such as naphthalimide; coumarin-based compounds such as coumarin; perinone perinone compounds such as the above; oxadiazole compounds such as oxadiazole; aldazine compounds; cyclopentadiene compounds such as 1,2,3,4,5-pentaphenyl-1,3-cyclopentadiene (PPCP); quinacridone compounds such as quinacridone and quinacridone red; pyridine compounds such as pyrrolopyridine and thiadiazolopyridine; triazine compounds such as 2,4-diphenyl-6-bis((12-phenylindolo)[2,3-a]carbazol-11-yl)-1,3,5-triazine (DIC-TRZ);Spiro compounds such as 2,2',7,7'-tetraphenyl-9,9'-spirobifluorene; phthalocyanine (H; ２ Pc), metallic or non-metallic phthalocyanine compounds such as copper phthalocyanine, boron compound materials, etc. Furthermore, host materials for the light-emitting layer include carbazole compounds such as 4,4'-bis(9H-carbazol-9-yl)biphenyl (CPB), silicon compounds, phenanthroline compounds, triphenylene compounds, etc.

[0018] The thickness of the emitting layer EML is 1 nm or more and 1000 nm or less.

[0019] The material of the electron transport layer ETL may be any material that can be used in general. Specifically, the material of the electron transport layer ETL may be phenyl-dipyrenylphosphine oxide (POPy ２), pyridine derivatives such as tris-1,3,5-(3'-(pyridin-3''-yl)phenyl)benzene (TmPhPyB), quinoline derivatives such as (2-(3-(9-carbazolyl)phenyl)quinoline (mCQ)), pyrimidine derivatives such as 2-phenyl-4,6-bis(3,5-dipyridylphenyl)pyrimidine (BPyPPM), pyrazine derivatives, bathophenanthroline (BPhen), phenanthroline derivatives such as 2,4-bis(4-biphenyl)-6-(4'-(2-pyridinyl)-4-biphenyl)-[1,3,5]triazine (MPT), triazine derivatives such as 3-phenyl-4-(1'-naphthyl)-5-phenyl-1,2,4-triazole (TAZ), oxazole derivatives such as 2-(4-biphenylyl)-5-(4-tert-butylphenyl-1,3,4-oxadiazole), oxadiazole derivatives such as (PBD), imidazole derivatives such as 2,2',2''-(1,3,5-benzotriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBI), aromatic ring carboxylic acid anhydrides such as naphthalene-1,4,5,8-tetracarboxylic dianhydride and 3,4,9,10-perylenetetracarboxylic dianhydride, aromatic ring carboxylic acid anhydrides such as N,N'-dimethyl-3,4,9,10-perylenetetracarboxylic diimide, Imide compounds, isoindigo derivatives and 2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione derivatives (diketopyrrolopyrroles), compounds with a carbonyl group such as toluxenone, 1,2,5-thiadiazole derivatives such as naphtho[1,2-c:5,6-c']bis[1,2,5]thiadiazole and benzo[c][1,2,5]thiadiazole, bis[2-(2-hydroxyphenyl)benzothiazolato]zinc (Zn(BTZ)), ２ ), tris(8-hydroxyquinolinato)aluminum (Alq ３), organosilane derivatives such as silole derivatives such as 2,5-bis(6'-(2',2''-bipyridyl))-1,1-dimethyl-3,4-diphenylsilole (PyPySPyPy), tris(2,4,6-trimethyl-3-(pyridin-3-yl)phenyl)borane (3TPYMB), boron-containing compounds, and the like can be used alone or in combination. Among these materials for the electron transport layer, POPy ２ Phosphine oxide derivatives such as Alq ３ It is preferable to use a metal complex such as the following, or a pyridine derivative such as TmPhPyB.

[0020] The thickness of the electron transport layer ETL is not particularly limited, but is preferably 10 nm or more and 200 nm or less.

[0021] The electron injection layer EIL may be made of any commonly used material. Specifically, an inorganic oxide layer may be used. Furthermore, by forming an electron injection layer on the inorganic oxide layer, the electron injection properties of the organic EL device can be improved. For example, polyethyleneimine may be used as the material for the electron injection layer.

[0022] The thickness of the electron injection layer EIL is not particularly limited, but is preferably 0.5 nm or more and 100 nm or less.

[0023] The material of the hole transport layer HTL may be an organic material, and for example, various p-type high molecular weight materials (organic polymers) and various p-type low molecular weight materials can be used alone or in combination. Specifically, examples of the material of the hole transport layer HTL include N,N'-di(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (α-NPD), N4,N4'-bis(dibenzo[b,d]thiophen-4-yl)-N4,N4'-diphenylbiphenyl-4,4'-diamine (DBTPB), N3,N3'''-bis(dibenzo[b,d]thiophen-4-yl)-N3,N3'''-diphenyl-[1,1':2',1'':2'',1'''-quaternium-1,1':2',1'''-tetramethyl ... Examples of suitable hole transport layer materials include fluorene-arylamine copolymers, fluorene-bithiophene copolymers, poly(N-vinylcarbazole), polyvinylpyrene, polyvinylanthracene, polythiophene, polyalkylthiophene, polyhexylthiophene, poly(p-phenylenevinylene), polytinylenevinylene, pyrene formaldehyde resin, ethylcarbazole formaldehyde resin, and derivatives thereof. These hole transport layer materials can also be used as mixtures with other compounds. For example, an example of a mixture containing polythiophene used as a hole transport layer material is poly(3,4-ethylenedioxythiophene / styrenesulfonic acid) (PEDOT / PSS).

[0024] The thickness of the hole transport layer HTL is not particularly limited, but is preferably 10 nm or more and 200 nm or less.

[0025] The material of the hole injection layer HIL may be an inorganic material or an organic material. Inorganic materials are more stable than organic materials, and therefore, higher resistance to oxygen and water can be easily obtained compared to the case where an organic material is used. The inorganic material is not particularly limited, but examples thereof include vanadium oxide (V ２ O ５ ), molybdenum oxide (MoO ３ ), ruthenium oxide (RuO ２As the organic material, low molecular weight materials such as dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN), 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), and fullerene, and poly(3,4-ethylenedioxythiophene) / polystyrene sulfonate (PEDOT:PSS) can be used.

[0026] The thickness of the hole injection layer HIL is not particularly limited, but is preferably 10 nm or more and 200 nm or less.

[0027] The auxiliary electrodes (12, 22, 32) are located on one side of the second electrodes (106, 206, 306), i.e., on the lower side, and are disposed at positions different from the EL elements (11, 21, 31). The auxiliary electrodes (12, 22, 32) include auxiliary electrode wiring (101b, 201b, 301b), a first metal layer M1, and a second metal layer M2. In FIGS. 1 to 3, the first metal layer M1 and the second metal layer M2 are stacked in two layers, but only one of the metal layers may be provided on the auxiliary electrode wiring.

[0028] In the auxiliary electrodes (12, 22, 32), the first metal layer M1 and the second metal layer M2 function as layers that electrically connect the auxiliary electrode wiring (101b, 201b, 301b) and the contact portion (13, 23, 33). The materials for the first metal layer M1 and the second metal layer M2 are not particularly limited, and known materials can be used. Specific examples include single layers of ITO (indium tin oxide), Mo, W, Al, Cu, Au, Cu-Al alloy, Al-Si alloy, Mo-W alloy, Ni-P alloy, etc., and laminates thereof. The thicknesses of the first metal layer M1 and the second metal layer M2 are not particularly limited, but are preferably 10 nm or more and 1000 nm or less. The materials for the first metal layer M1 and the second metal layer M2 may be the same material or different materials. When the first metal layer M1 and the second metal layer M2 are made of the same material, the first metal layer M1 and the second metal layer M2 may be provided as a single layer rather than being stacked.

[0029] A contact portion (13, 23, 33) is interposed between the auxiliary electrode (12, 22, 32) and the second electrode (106, 206, 306), and the contact portion (13, 23, 33) contains particles P.

[0030] In the auxiliary electrode contact (10, 20, 30), the second electrode (106, 206, 306) has a portion that overlaps with the auxiliary electrode (12, 22, 32) via the particle P and the EL layer (hole transport layer HTL / hole injection layer HIL in Figures 1 and 2, electron transport layer ETL / electron injection layer EIL in Figure 3) on the particle P. This configuration enables the second electrode (106, 206, 306) to be electrically connected to the auxiliary electrode (12, 22, 32).

[0031] The EL layers (hole transport layer HTL / hole injection layer HIL in Figures 1 and 2, and electron transport layer ETL / electron injection layer EIL in Figure 3) interposed between the auxiliary electrodes (12, 22, 32) and the second electrodes (106, 206, 306) are made of insulating materials. Therefore, it was necessary to ensure electrical continuity between the second electrodes and the auxiliary electrodes by etching these EL layers at the auxiliary electrode contacts or by devising a method to prevent the EL layer from forming at the auxiliary electrode contacts. However, etching only the EL layer at the auxiliary electrode contacts was technically difficult. Furthermore, preventing the formation of the EL layer at the auxiliary electrode contacts required the installation of a separate structure, complicating the process.

[0032] In light of the above background, the applicant discovered that providing particles P on the auxiliary electrode contacts (10, 20, 30) would allow electrical continuity between the second electrodes (106, 206, 306) and the auxiliary electrodes (12, 22, 32).

[0033] The particles P are insulating particles or conductive particles. When the particles P are conductive particles, they are preferably one or more of a conductive oxide, carbon, and metal. More preferably, they are ITO particles, carbon nanohorns, Ag particles, etc. Note that a carbon nanohorn refers to a structure in which a graphene sheet is rolled into a cone shape, and typically exists as an aggregate in which multiple carbon nanohorns aggregate with their apexes facing outward.

[0034] By providing particles P on the auxiliary electrode 12, the insulating HTL / HIL is not formed uniformly on the auxiliary electrode 12, as shown in Fig. 4A, and a step in the HTL / HIL occurs. Due to the step in the HTL / HIL, as shown in Fig. 4B, the second electrode 106 is in contact with the auxiliary electrode 12 by utilizing the portion where the HTL / HIL is not formed (the step portion), thereby enabling electrical conduction between the two. When the second electrode 106 and the auxiliary electrode 12 are in contact, electrical conduction between the second electrode 106 and the auxiliary electrode 12 is possible even if the particles P are insulating particles.

[0035] On the other hand, if the particles P are conductive particles, even if the second electrode 106 is not in direct contact with the auxiliary electrode 12, the second electrode 106 and the particles P come into contact due to a break in the HTL / HIL, and the particles P are present in the conduction path between the second electrode and the auxiliary electrode 12, thereby ensuring conduction between the two.

[0036] The diameter of the particles P is 1 nm or more and 1000 nm or less. The upper limit of the diameter of the particles P is preferably 500 nm, more preferably 200 nm, and even more preferably 50 nm. The lower limit of the diameter of the particles P is preferably 1 nm, more preferably 10 nm.

[0037] The particles P are arranged on the auxiliary electrodes (12, 22, 32) to a thickness of 2 nm to 2000 nm. The lower limit of the thickness at which the particles P are arranged is preferably 10 nm, more preferably 50 nm, and even more preferably 100 nm. The upper limit of the thickness at which the particles P are arranged is preferably 2000 nm, more preferably 1000 nm, and even more preferably 500 nm.

[0038] The material of the planarization film (102, 202, 302) is not particularly limited, and any known material can be used. Specific examples include organic resin films. The thickness of the planarization film (102, 202, 302) is 10 nm or more and 5000 nm or less.

[0039] The inorganic bank (103, 203, 303) improves the adhesion of the organic bank (105, 205, 305) and functions as a layer for reducing the risk of short circuit. The inorganic bank material is an inorganic material, and known inorganic materials can be used. Specific examples include SiO ２The inorganic bank (103, 203, 303) has a thickness of 10 nm to 100 nm.

[0040] The organic bank (105, 205, 305) is a water-repellent bank and functions as a layer that holds ink (e.g., EML material) ejected by inkjet printing at a desired position. The organic bank is made of an organic material, and any known organic material can be used. The film thickness of the organic bank (105, 205, 305) is 1,000 nm or more and 5,000 nm or less.

[0041] The inorganic films (107, 207, 307) function as sealing films. The material of the inorganic film is not particularly limited, and known materials can be used. Specific examples include SiO ２ The inorganic film (107, 207, 307) has a thickness of 50 nm or more and 2000 nm or less.

[0042] There are no particular limitations on the material of the sealing film (108, 208, 308), and any known material can be used. The thickness of the sealing film (108, 208, 308) is 20 μm or more and 500 μm or less.

[0043] <Method of Manufacturing Top-Emission EL Light-Emitting Device 1> The top-emission EL light-emitting device (inverted structure) 1 according to this embodiment can be manufactured by, for example, the steps shown in Table 1 below and FIG.

[0044]

[0045] Step 1: A backplane BP is fabricated, which is an active matrix substrate including BP wiring 101a, a planarization film 102, and auxiliary electrode wiring 101b. The BP wiring 101a is connected to the transistors of the active matrix substrate, connecting the transistors to the EL elements 11. The auxiliary electrode wiring 101b is part of the auxiliary electrode 12, connecting the first and second metal layers M1 and M2 to an auxiliary electrode power supply portion (not shown) formed on the backplane BP.

[0046] Step 2: A first metal film and a second metal film are sequentially formed on the auxiliary electrode wiring 101b by sputtering, followed by resist application, exposure, development, etching of the second metal film, and resist removal to form a second metal layer M2, and similarly by resist application, exposure, development, etching of the first metal film, and resist removal to form a first metal layer M1. Step 2 forms an auxiliary electrode 12 composed of the auxiliary electrode wiring 101b, the first metal layer M1, and the second metal layer M2. In the step of Figure 5, the first metal layer M1 and the second metal layer M2 are each formed by etching using separate resists, but the first metal layer M1 and the second metal layer M2 may also be formed in a single etching step using the same resist.

[0047] Step 3: A conductive film to be the first electrode 104 (cathode) is formed on the BP wiring 101a by sputtering, and then processes of resist application, exposure, development, cathode etching, and resist removal are performed to form the first electrode 104. Thereafter, EIL / ETL are sequentially formed on the first electrode 104 by sputtering, and processes of resist application, exposure, development, EIL / ETL etching, and resist removal are performed to pattern the EIL / ETL into a desired shape.

[0048] Step 4: An inorganic insulating film is formed by CVD (chemical vapor deposition) over the entire surface of the substrate, including the ETL of the EL element 11 and the auxiliary electrode 12, and then the inorganic bank 103 is formed by applying a resist, exposing it to light, developing it, etching the inorganic bank, and removing the resist. An organic insulating film is then applied to the inorganic bank 103, and the organic bank 105 is formed by exposing it to light and developing it. A plurality of openings are provided in the inorganic bank 103 and the organic bank 105. One of the openings is where the emitting layer EML of the EL element 11 is to be formed, and the other opening is an auxiliary electrode via where the contact portion 13 of the auxiliary electrode contact 10 is to be formed.

[0049] Step 5: Particles P are placed in the auxiliary electrode vias located on the second metal layer M2 of the auxiliary electrode contact 10 and dried.

[0050] The particles P are arranged by a dispenser or by printing, such as inkjet printing, screen printing, or gravure printing, and preferably inkjet printing.

[0051] Step 6: Red, blue, or green ink is applied onto the EIL / ETL of the EL element 11 to form an emitting layer EML, which is then dried.

[0052] The ink is applied by a dispenser or by printing, such as inkjet printing, screen printing, or gravure printing, with inkjet printing being preferred.

[0053] Step 7: The HTL / HIL is sequentially evaporated onto the entire surface of the substrate, including the emitting layer EML of the EL element 11 and the second metal layer M2 on which the particles P of the auxiliary electrode contact 10 are arranged, and then the second electrode 106 (anode) is formed on the HTL / HIL by sputtering.

[0054] The contact portion 13 is formed by the steps of arranging particles P on the auxiliary electrode 12 as shown in step 6, and forming an EL layer (HTL / HIL) on the auxiliary electrode 12 on which the particles P are arranged as shown in step 7.

[0055] Because the HTL / HIL (or ETL / EIL in the case of Figure 3 described later) is formed by vapor deposition, the molecules flying from the deposition source to the substrate have high linearity, making it difficult for the HTL / HIL to form under the eaves of the particles P ( Figure 4A ). In other words, the HTL / HIL is not formed uniformly, resulting in a step under the eaves of the particles P. On the other hand, the second electrode 106, formed by sputtering, has molecules incident from various directions, so it wraps around to the underside of the eaves of the particles P and contacts the upper part of the auxiliary electrode 12 ( Figure 4B ). Contact between the second electrode 106 and the auxiliary electrode 12 allows electrical continuity between the second electrode 106 and the auxiliary electrode 12 at the auxiliary electrode contact 10. Alternatively, although not shown, electrical continuity between the second electrode 106 and the auxiliary electrode 12 can be achieved via the conductive particles P, even if the second electrode 106 does not contact the auxiliary electrode 12.

[0056] Thereafter, an inorganic film 107 is formed on the second electrode 106 by CVD, and finally, a sealing film 108 is formed on the inorganic film 107, thereby completing the top-emission type EL light-emitting device 1 according to this embodiment.

[0057] <Method of Manufacturing Top-Emission EL Light-Emitting Device 2> The top-emission EL light-emitting device (inverted structure) 2 according to this embodiment can be manufactured, for example, by the procedure shown in Table 2 below and FIG.

[0058]

[0059] Step 1: A backplane BP is fabricated as an active matrix substrate including BP wiring 201a, a planarizing film 202, and auxiliary electrode wiring 201b. Descriptions of the same steps and components as those of the top-emission EL light-emitting device 1 will be omitted.

[0060] Step 2: A first metal layer M1 and a second metal layer M2 are formed in this order on the auxiliary electrode wiring 201b to form the auxiliary electrode 22.

[0061] Step 3: A first electrode 204 (cathode) is formed on the BP wiring 201a.

[0062] Step 4: An inorganic bank 203 and an organic bank 205 having a plurality of openings are formed on the entire surface of the substrate including the first electrode 204 of the EL element 21 and the auxiliary electrode 22 .

[0063] Step 5: Particles P are placed in the auxiliary electrode vias located on the second metal layer M2 of the auxiliary electrode contact 20 and allowed to dry.

[0064] The particles P are arranged by a dispenser or by printing, such as inkjet printing, screen printing, or gravure printing, and preferably inkjet printing.

[0065] Step 6: EIL / ETL are applied in this order onto the first electrode 204 (cathode) of the EL element 21, and then any one of red, blue, and green inks is applied thereon to form an emitting layer EML, which is then dried.

[0066] The ink is applied by a dispenser or by printing, such as inkjet printing, screen printing, or gravure printing, with inkjet printing being preferred.

[0067] Step 7: The HTL / HIL is sequentially evaporated onto the entire surface of the substrate, including the emitting layer EML of the EL element 21 and the second metal layer M2 on which the particles P of the auxiliary electrode contact 20 are arranged, and then the second electrode 206 (anode) is formed on the HTL / HIL by sputtering.

[0068] The contact portion 23 is formed by the steps of arranging particles P on the auxiliary electrode 22 as shown in step 6, and forming an EL layer (HTL / HIL) on the auxiliary electrode 22 on which the particles P are arranged as shown in step 7.

[0069] Thereafter, an inorganic film 207 is formed on the second electrode 206 by CVD, and finally, a sealing film 208 is formed on the inorganic film 207, thereby completing the top-emission type EL light-emitting device 2 according to this embodiment.

[0070] <Method of Manufacturing Top-Emission EL Light-Emitting Device 3> The top-emission EL light-emitting device (forward structure) 3 according to this embodiment can be manufactured, for example, by the procedure shown in Table 3 below and FIG.

[0071]

[0072] Step 1: A backplane BP is fabricated, which is an active matrix substrate including BP wiring 301a, a planarizing film 302, and auxiliary electrode wiring 301b.

[0073] Step 2: A first metal film and a second metal film are sequentially formed by sputtering on the BP wiring 301a, the planarization film 302, and the auxiliary electrode wiring 301b. Then, a resist is applied to the second metal film, exposed, and developed to form a second metal layer M2. Similarly, the first metal film is etched using the second metal layer M2 as a mask to form a first metal layer M1. This forms the auxiliary electrode 32.

[0074] Step 3: After a conductive layer to be the first electrode 304 (anode) is formed on the BP wiring 301a by sputtering, the first electrode 304 is formed by patterning.

[0075] Step 4: An inorganic bank 303 and an organic bank 305 are formed over the entire surface of the substrate including the first electrode 304 of the EL element 31 and the auxiliary electrode 32, and an opening is formed above the first electrode 304 and an auxiliary electrode via is formed above the second metal layer M2.

[0076] Step 5: Particles P are placed in the auxiliary electrode vias located on the second metal layer M2 and dried.

[0077] The particles P are arranged by a dispenser or by printing, such as inkjet printing, screen printing, or gravure printing, and preferably inkjet printing.

[0078] Step 6: HIL / HTL are applied in order onto the first electrode 304 (anode) of the EL element 31, and then any one of red, blue and green inks is applied thereon to form an emitting layer EML, which is then dried.

[0079] The ink is applied by a dispenser or by printing, such as inkjet printing, screen printing, or gravure printing, with inkjet printing being preferred.

[0080] Step 7: An ETL / EIL is sequentially evaporated onto the entire surface of the substrate, including the emitting layer EML of the EL element 31 and the second metal layer M2 on which the particles P of the auxiliary electrode contact 30 are arranged, and then a second electrode 306 (cathode) is formed on the ETL / EIL by sputtering.

[0081] The contact portion 33 is formed by the steps of arranging particles P on the auxiliary electrode 32 as shown in step 6, and forming an EL layer (ETL / EIL) on the auxiliary electrode 32 on which the particles P are arranged as shown in step 7.

[0082] In the top-emission type EL light-emitting device 3, as in the top-emission type EL light-emitting devices 1 and 2, the presence of particles P causes a gap in the EL layer (ETL / EIL), thereby enabling electrical continuity between the auxiliary electrode 32 and the second electrode 306 at the auxiliary electrode contact 30.

[0083] Thereafter, an inorganic film 307 is formed on the second electrode 306 by CVD, and finally, a sealing film 308 is formed on the inorganic film 307, thereby completing the top-emission type EL light-emitting device 3 according to this embodiment.

[0084] The top-emission type EL light-emitting device according to this embodiment will be specifically described with reference to the following examples and comparative examples, but the present invention is not limited to these examples and comparative examples. ｎ For example, 2. E + 03 = 2.0 × 10 ３ is.

[0085] A first electrode made of ITO was formed on a substrate, a bank made of an organic material was formed on the first electrode, multiple openings were made in the organic bank, and the openings were filled with the particles described in Examples 1 to 5. The step profile, surface roughness, and total particle film thickness at this time were measured. In Comparative Example 1, the step profile and surface roughness were measured for a bank in which no particles were filled in the openings (blank). The step profiles for Comparative Example 1 and Examples 1 to 5 are shown in Figures 8 to 13, respectively.

[0086] Next, after filling the particles described in Examples 1 to 5, a hole transport layer HTL and a hole injection layer HIL were sequentially formed, and a second electrode made of ITO was formed on the hole injection layer HIL. At this stage, the current density between the first electrode and the second electrode was measured. In Comparative Example 1, the current density between the first electrode and the second electrode was measured without filling the bank openings with particles. The current densities for the Comparative Example and each Example are shown in Table 4 and Figures 14 to 19, respectively.

[0087] The step profile was measured using a stylus profiler (P-16 manufactured by KLA-Tenchore Corporation).

[0088] The surface roughness was measured using a stylus profiler (P-16, manufactured by KLA-Tenchore Corporation).

[0089] The total particle thickness was measured using a stylus profiler (P-16, manufactured by KLA-Tenchore Corporation).

[0090] The current density was measured using a DC voltage / current generator, Model 6244, manufactured by ADC Corporation.

[0091]

[0092] In FIG. 8, where no particles are provided in the bank opening, the inside of the bank opening is flat.

[0093] Figure 9 shows the step profile when the bank opening is filled with ITO particles to a thickness of 200 nm, and Figure 10 shows the step profile when the opening is filled with carbon nanohorns to a thickness of 150 nm. Figures 11 to 13 show the step profiles when Ag particles are filled to thicknesses of 235 nm, 350 nm, and 430 nm. Comparing Figures 9 to 13 with Figure 8, irregularities are observed near the bottom of the opening, and the surface roughness (Ra) within the opening was 70 nm or less in Example 1, 25 nm or less in Example 2, and 70 nm or less in Examples 3 to 5. In other words, it was found that filling the bank opening with particles increases the surface roughness within the bank opening.

[0094] 14 shows the current density between the first electrode and the second electrode in Comparative Example 1. The current density at a voltage of 10 V was 361 mA / cm ２ 15 to 19 of Examples 1 to 5, it was found that the current density at a voltage of 10 V was about 2 to 3 times larger than that of Comparative Example 1. This example showed that by filling the electrode vias in the bank openings with particles, the presence of the particles reduces the electrical resistance between the electrodes sandwiching the contact portion, even if an EL layer is provided in the auxiliary electrode contact portion.

[0095] 15 to 16, in which the auxiliary electrode vias are filled with particles, the current density is higher than that in FIG. 14, and it can be seen that the electrical resistance between the electrodes is low. In FIGS. 17 to 19, in which Ag particles are filled, the current density is also higher than that in FIG. 14, and it can be seen that the electrical resistance between the electrodes is low. In FIGS. 17 to 19, in which Ag particles are filled, the current density is similar regardless of the Ag particle film thickness, which reflects the fact that the surface roughness of the Ag particle film is similar regardless of the particle film thickness.

[0096] DESCRIPTION OF SYMBOLS 1... Top-emission type EL light-emitting device (inverted structure, EIL / ETL sputtered film) 2... Top-emission type EL light-emitting device (inverted structure, EIL / ETL coated film) 3... Top-emission type EL light-emitting device (normal structure, HIL / HTL coated film) 10, 20, 30... Auxiliary electrode contact 11, 21, 31... EL element 12, 22, 32... Auxiliary electrode 13, 23, 33... Contact portion 101a, 201a, 301a... BP wiring 101b, 201b, 301b... Auxiliary electrode wiring 102, 202, 302... Planarization film 103, 203, 303... Inorganic bank 104, 204, 304... First electrode 105, 205, 305... Organic bank 106, 206, 306... Second electrode 107, 207, 307... inorganic film 108, 208, 308... sealing film EML... light emitting layer ETL... electron transport layer EIL... electron injection layer HTL... hole transport layer HIL... hole injection layer P... particles M1... first metal layer M2... second metal layer

Claims

1. A top-emission type EL light-emitting device having an EL element in which a first electrode, a light-emitting layer, and a transparent second electrode are stacked, and an auxiliary electrode, wherein the first electrode and the light-emitting layer are formed on one side of the second electrode, the auxiliary electrode is disposed on the one side of the second electrode at a position different from the EL element, and a contact portion is interposed between the auxiliary electrode and the second electrode, and the contact portion contains particles.

2. The top-emitting electroluminescent light-emitting device of claim 1, wherein the particles are electrically conductive.

3. The top-emission type EL light-emitting device according to claim 1 or 2, wherein the diameter of said particles is 1 nm or more and 1000 nm or less.

4. The top-emission type EL light-emitting device according to any one of claims 1 to 3, wherein the particles are one or more of conductive oxide, carbon, and metal.

5. The top-emission type EL light-emitting device according to any one of claims 1 to 4, wherein the particles are arranged on the auxiliary electrode to a thickness of 2 nm to 2000 nm.

6. A top-emission type EL light-emitting device according to any one of claims 1 to 5, wherein the second electrode has a portion that overlaps with the auxiliary electrode, with the particles and the EL layer on the particles interposed therebetween.

7. A method for manufacturing a top-emission type EL light-emitting device having an EL element in which a first electrode, a light-emitting layer, and a transparent second electrode are stacked, and an auxiliary electrode, wherein the top-emission type EL light-emitting device has an auxiliary electrode contact that connects the auxiliary electrode and the second electrode, and the process for forming the auxiliary electrode contact has the steps of: forming the auxiliary electrode; arranging particles on the auxiliary electrode; forming an EL layer on the auxiliary electrode on which the particles are arranged; and forming the second electrode on the EL layer.

8. The method for manufacturing a top-emission type EL light-emitting device according to claim 7, wherein the particles are conductive.

9. The method for manufacturing a top-emission type EL light-emitting device according to claim 7 or 8, wherein the diameter of the particles is 1 nm or more and 1000 nm or less.

10. The method for manufacturing a top-emission type EL light-emitting device according to any one of claims 7 to 9, wherein the particles are one or more of conductive oxide, carbon, and metal.

11. The method for manufacturing a top-emission type EL light-emitting device according to any one of claims 7 to 10, wherein the particles are arranged on the auxiliary electrode to a thickness of 2 nm to 2000 nm.

12. The method for manufacturing a top-emission type EL light-emitting device according to any one of claims 7 to 11, wherein the particles are arranged by a dispenser or printing.

13. The method for manufacturing a top-emission type EL light-emitting device according to claim 12, wherein the printing is inkjet printing, screen printing, or gravure printing.

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