WO2020012686A1 - Élément électroluminescent organique - Google Patents

Élément électroluminescent organique Download PDF

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WO2020012686A1
WO2020012686A1 PCT/JP2019/005633 JP2019005633W WO2020012686A1 WO 2020012686 A1 WO2020012686 A1 WO 2020012686A1 JP 2019005633 W JP2019005633 W JP 2019005633W WO 2020012686 A1 WO2020012686 A1 WO 2020012686A1
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layer
light
organic
intermediate connector
light emitting
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PCT/JP2019/005633
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Japanese (ja)
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大津　信也
邦夫 谷
智美 菅井
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コニカミノルタ株式会社
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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
    • H05B33/12—Light sources with substantially two-dimensional radiating surfaces
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers

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  • the present invention relates to an organic electroluminescence device, and more particularly, to an organic electroluminescence device having improved voltage rise, durability and color shift during driving.
  • An organic electroluminescence element (hereinafter, also referred to as an organic EL element) has a configuration in which a light-emitting layer containing a compound that emits light is sandwiched between a cathode and an anode. By applying an electric field thereto, holes injected from the anode and electrons injected from the cathode are recombined in the light emitting layer to generate excitons. It is a light emitting element utilizing light emission (fluorescence / phosphorescence) when the exciton is deactivated.
  • the organic EL element is an all-solid-state element in which a gap between electrodes is formed of an organic material film having a thickness of only about submicron, and can emit light at a voltage of about several volts to several tens of volts. Therefore, it is expected to be used for next-generation flat displays and lighting.
  • an organic electroluminescent material (hereinafter, also referred to as an organic EL material) is an insulating organic molecule, electrons and holes cannot be directly injected into a dopant from an anode and a cathode (the charge according to the so-called Ohm rule). Injection is not possible). In other words, holes cannot be directly injected due to a large energy barrier between the anode and the light-emitting layer. Therefore, in order to inject and transport charges into the organic material which is an insulator, an ultrathin film (100 nm or less) must be used. It is necessary to reduce the energy barrier. Therefore, a thin-film hole injection / transport layer having intermediate energy is required between the anode and the light emitting layer.
  • a nitrogen-containing aromatic compound for the electron transport layer, a first light emitting layer, a second light emitting layer, and an intermediate connector layer between the first light emitting layer and the second light emitting layer.
  • a general electron transport material is used for the intermediate connector layer or the electron transport layer existing between the first light emitting layer and the intermediate connector layer in the organic EL device having the organic EL device, voltage rise during driving, durability and color There is a problem in terms of deviation.
  • a nitrogen-containing aromatic compound to suppress the aggregation of silver (see, for example, Patent Documents 2 and 3)
  • Patent Documents 2 and 3 there is a report that suppresses the diffusion of an alkali metal or an alkaline earth metal. Absent.
  • JP 2010-166070 A Patent No. 5577186 International Publication No. 2013/161602
  • the present invention has been made in view of the above-described problems and circumstances, and a problem to be solved is to provide an organic electroluminescent element in which voltage rise during driving, durability and color shift are improved.
  • an intermediate connector layer provided between the first light-emitting layer and the second light-emitting layer be made of an alkali metal or an alkaline earth metal.
  • diffusion of an alkali metal or an alkaline earth metal into the light emitting layer is suppressed. That is, the above object according to the present invention is solved by the following means.
  • An organic electroluminescent element having The intermediate connector layer contains an alkali metal or an alkaline earth metal
  • An organic electroluminescence device, wherein the intermediate connector layer or a layer between the intermediate connector layer and the first light emitting layer contains a compound having a structure represented by the following general formula (1).
  • A1 and A2 represent a residue forming a 6-membered aromatic heterocycle together with a nitrogen atom, and the 6-membered aromatic heterocycle may be condensed.
  • L represents a single bond, an aromatic hydrocarbon ring, an aromatic heterocyclic ring, or an alkyl group.
  • the intermediate connector layer or a layer between the intermediate connector layer and the first light-emitting layer contains a compound having a structure represented by the following general formula (2).
  • Ra, Rb and Rc represent a hydrogen atom or a substituent. At least one of Ra, Rb, and Rc represents a 6-membered aromatic heterocycle, and the 6-membered aromatic heterocycle may be condensed.
  • n1 represents an integer of 1 to 4.
  • the organic electroluminescence device contains a compound having a structure represented by the following general formula (3).
  • Re, Rd and Rf represent a hydrogen atom or a substituent. At least one of Re, Rd and Rf represents a 6-membered aromatic heterocycle, and the 6-membered aromatic heterocycle may be condensed.
  • n2 represents an integer of 1 to 4.
  • the intermediate connector layer or a layer between the intermediate connector layer and the first light emitting layer contains a compound having a structure represented by the following general formula (4).
  • Rg, Rh, Ri and Rj represent a hydrogen atom or a substituent. At least one of Rg, Rh, Ri, and Rj represents a 6-membered aromatic heterocycle, and the 6-membered aromatic heterocycle may be condensed.
  • L 2 represents a single bond, an aromatic hydrocarbon ring, an aromatic heterocyclic ring or an alkyl group.
  • the intermediate connector layer or a layer between the intermediate connector layer and the first light emitting layer contains a compound having a structure represented by the following general formula (5).
  • Organic electroluminescence element Ar represents carbazole, dibenzofuran, azadibenzofuran, dibenzothiophene, azadibenzothiophene, azacarbazole, naphthalene, anthracene, phenanthrene or fluorene.
  • Rk represents a hydrogen atom or a substituent. At least two of Rk represent a 6-membered aromatic heterocycle, and the 6-membered aromatic heterocycle may be condensed.
  • n3 represents an integer of 2 or more.
  • the intermediate connector layer or a layer between the intermediate connector layer and the first light emitting layer contains a compound having a structure represented by the following general formula (6). .
  • Y 1 and Y 2 represent O, S or NR 1 .
  • X 1 to X 16 represent CR 2 or N. At least two of X 1 to X 16 represent N.
  • L 1 represents a single bond, an aromatic hydrocarbon ring, an aromatic heterocyclic ring or an alkyl group.
  • R 1 and R 2 represent an aromatic hydrocarbon ring, an aromatic heterocyclic ring or an alkyl group.
  • An organic electroluminescent element having The intermediate connector layer contains a lanthanoid, Organic electroluminescence in which the intermediate connector layer or a layer between the intermediate connector layer and the first light emitting layer contains any of compounds having a structure represented by the following general formulas (1) to (6). element.
  • A1 and A2 represent a residue forming a 6-membered aromatic heterocycle together with a nitrogen atom, and the 6-membered aromatic heterocycle may be condensed.
  • L represents a single bond, an aromatic hydrocarbon ring, an aromatic heterocyclic ring, or an alkyl group.
  • Ra, Rb and Rc represent a hydrogen atom or a substituent. At least one of Ra, Rb, and Rc represents a 6-membered aromatic heterocycle, and the 6-membered aromatic heterocycle may be condensed. n1 represents an integer of 1 to 4. ]
  • Re, Rd and Rf represent a hydrogen atom or a substituent. At least one of Re, Rd and Rf represents a 6-membered aromatic heterocycle, and the 6-membered aromatic heterocycle may be condensed. n2 represents an integer of 1 to 4. ]
  • Rg, Rh, Ri and Rj represent a hydrogen atom or a substituent. At least one of Rg, Rh, Ri, and Rj represents a 6-membered aromatic heterocycle, and the 6-membered aromatic heterocycle may be condensed.
  • L 2 represents a single bond, an aromatic hydrocarbon ring, an aromatic heterocyclic ring or an alkyl group.
  • Ar represents carbazole, dibenzofuran, azadibenzofuran, dibenzothiophene, azadibenzothiophene, azacarbazole, naphthalene, anthracene, phenanthrene or fluorene.
  • Rk represents a hydrogen atom or a substituent. At least two of Rk represent a 6-membered aromatic heterocycle, and the 6-membered aromatic heterocycle may be condensed.
  • n3 represents an integer of 2 or more.
  • Y 1 and Y 2 represent O, S or NR 1 .
  • X 1 to X 16 represent CR 2 or N. At least two of X 1 to X 16 represent N.
  • L 1 represents a single bond, an aromatic hydrocarbon ring, an aromatic heterocyclic ring or an alkyl group.
  • R 1 and R 2 represent an aromatic hydrocarbon ring, an aromatic heterocyclic ring or an alkyl group.
  • the compound having a structure represented by the general formula (1) used in the organic electroluminescence device of the present invention has an aromatic heterocycle containing a nitrogen atom in the molecule, the compound may contain an alkali metal or an alkaline earth metal. Interact and fix alkali or alkaline earth metals, lanthanoids. That is, diffusion of an alkali metal or an alkaline earth metal can be suppressed.
  • the compound having the structure represented by the general formula (2), (3) or (6) as the compound having the structure A the compound having the structure B is represented by the general formula (4) or (4).
  • the diffusion of the alkali metal or alkaline earth metal and the lanthanoid can be surely suppressed, and as a result, the voltage rise during driving, durability and color shift are improved. It is presumed that it can be done.
  • Schematic diagram for explaining the charge transport / injection mechanism Schematic diagram showing an example of the configuration of an organic EL element
  • Schematic diagram of the display unit A Pixel circuit diagram Schematic diagram of passive matrix type full color display device
  • Schematic diagram of lighting device Schematic diagram of lighting device
  • the organic electroluminescent device of the present invention includes an anode, a cathode, a first light-emitting layer and a second light-emitting layer provided between the anode and the cathode, and a light-emitting device between the first light-emitting layer and the second light-emitting layer.
  • an intermediate connector layer provided in the organic electroluminescence device, wherein the intermediate connector layer contains an alkali metal or an alkaline earth metal, and the intermediate connector layer, or the intermediate connector layer and the first
  • the layer having a structure represented by the general formula (1) is contained in a layer between the light emitting layers. This feature is a technical feature common or corresponding to each of the following embodiments.
  • the intermediate connector layer or a layer between the intermediate connector layer and the first light emitting layer may include a compound having a structure represented by any of the general formulas (2) to (6). It is preferable to contain any of them because they can interact with an alkali metal or an alkaline earth metal and suppress diffusion of the alkali metal or the alkaline earth metal.
  • the intermediate connector layer contains Li, Na, K, Mg or Ca interacts with a nitrogen atom in the compound having the structure represented by the general formula (1), and forms an alkali metal or alkaline earth. This is preferable because diffusion of metal can be suppressed.
  • the intermediate connector layer contains any of the compounds having the structures represented by the general formulas (1) to (6), diffusion of an alkali metal or an alkaline earth metal is suppressed, and It is preferable from the viewpoint of preventing intrusion, and the layer between the intermediate connector layer and the first light emitting layer contains any of the compounds having the structures represented by the general formulas (1) to (6). Is preferred in that the diffusion of an alkali metal or an alkaline earth metal is suppressed and penetration into the light emitting layer is prevented.
  • the organic electroluminescence element of the present invention includes an anode, a cathode, a first light emitting layer and a second light emitting layer provided between the anode and the cathode, the first light emitting layer and the second light emitting layer. And an intermediate connector layer provided therebetween, wherein the intermediate connector layer contains a lanthanoid (hereinafter, also referred to as La metal), and the intermediate connector layer or the intermediate connector is provided.
  • the layer between the layer and the first light emitting layer contains any of the compounds having the structures represented by the following general formulas (1) to (6).
  • the compound having the structure represented by any of the general formulas (1) to (6) has an aromatic heterocycle having a nitrogen atom in the molecule, the compound interacts with the lanthanoid and suppresses the diffusion of the lanthanoid.
  • the lanthanoid is preferably any of samarium (Sm), europium (Eu) and ytterbium (Yb) in that diffusion can be suppressed.
  • ⁇ is used in the meaning including the numerical value described before and after it as a lower limit and an upper limit.
  • the organic EL device of the present invention includes an anode, a cathode, a first light-emitting layer and a second light-emitting layer provided between the anode and the cathode, and between the first light-emitting layer and the second light-emitting layer.
  • An intermediate connector layer provided, wherein the intermediate connector layer contains an alkali metal or an alkaline earth metal, and the intermediate connector layer, or the intermediate connector layer and the first light emission
  • the layer between the layers contains a compound having a structure represented by the following general formula (1).
  • another organic EL device of the present invention includes an anode, a cathode, a first light emitting layer and a second light emitting layer provided between the anode and the cathode, and the first light emitting layer and the second light emitting layer.
  • An intermediate connector layer provided between the layers, wherein the intermediate connector layer contains a lanthanoid, the intermediate connector layer, or the intermediate connector layer and the first light emitting layer
  • the intervening layer contains any of the compounds having the structures represented by the following general formulas (1) to (6).
  • a first electron transport layer described later is exemplified as a layer between the intermediate connector layer and the first light emitting layer.
  • alkali metal or alkaline earth metal contained in the intermediate connector layer examples include Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Ra and the like.
  • Li, Na, K, Mg or Ca is preferable in that it interacts with a nitrogen atom in the compound having the structure represented by 1) and can suppress diffusion of an alkali metal or an alkaline earth metal, and Li is preferably used. Particularly preferred.
  • the lanthanoid contained in the intermediate connector layer may be any of samarium (Sm), europium (Eu) and ytterbium (Yb), according to the structures represented by the general formulas (1) to (6). It is preferable because it interacts with a nitrogen atom in a compound having the compound to suppress diffusion of a lanthanoid.
  • A1 and A2 represent a residue forming a 6-membered aromatic heterocycle together with a nitrogen atom, and the 6-membered aromatic heterocycle may be condensed.
  • L represents a single bond, an aromatic hydrocarbon ring, an aromatic heterocyclic ring, or an alkyl group.
  • examples of the residue represented by A1 and A and forming a 6-membered aromatic heterocyclic ring formed together with a nitrogen atom include pyridine, pyrimidine, pyrazine, triazine and the like.
  • examples of the condensed 6-membered aromatic heterocycle include quinazoline, quinoline, isoquinoline, azadibenzofuran, azacarbazole, azadibenzothiophene, benzimidazole ring, benzoquinoline ring, and benzoisoquinoline ring.
  • aromatic hydrocarbon ring represented by L phenyl, biphenyl, terphenyl, naphthalene, anthracene, phenanthrene or fluorene
  • aromatic heterocyclic ring carbazole, dibenzofuran, azadibenzofuran, dibenzothiophene, azadibenzothiophene, azacarbazole
  • alkyl group include methyl, ethyl, isopropyl, propyl, butyl, t-butyl, hexyl and the like.
  • the compound having a structure represented by the general formula (1) is preferably a compound having a structure represented by any of the following general formulas (2) to (6).
  • Ra, Rb and Rc represent a hydrogen atom or a substituent. At least one of Ra, Rb, and Rc represents a 6-membered aromatic heterocycle, and the 6-membered aromatic heterocycle may be condensed. n1 represents an integer of 1 to 4. ]
  • examples of the substituent represented by Ra, Rb, and Rc include an aromatic hydrocarbon ring, an aromatic heterocyclic ring, alkyl, cyano, and a halogen atom.
  • the 6-membered aromatic heterocyclic ring represented by at least one of Ra, Rb and Rc is the same as those described for A1 and A2 in formula (1).
  • Re, Rd and Rf represent a hydrogen atom or a substituent. At least one of Re, Rd and Rf represents a 6-membered aromatic heterocycle, and the 6-membered aromatic heterocycle may be condensed. n2 represents an integer of 1 to 4. ]
  • the substituents represented by Re, Rd and Rf are the same as the substituents represented by Ra, Rb and Rc in the general formula (2).
  • the aromatic heterocycle in which at least one of Re, Rd, and Rf is a 6-membered aromatic ring is the same as those described for A1 and A2 in Formula (1).
  • Rg, Rh, Ri and Rj represent a hydrogen atom or a substituent. At least one of Rg, Rh, Ri, and Rj represents a 6-membered aromatic heterocycle, and the 6-membered aromatic heterocycle may be condensed.
  • L 2 represents a single bond, an aromatic hydrocarbon ring, an aromatic heterocyclic ring or an alkyl group.
  • the substituents represented by Rg, Rh, Ri, and Rj are the same as the substituents represented by Ra, Rb, and Rc in the general formula (2).
  • the aromatic heterocyclic ring in which at least one of Rg, Rh, Ri, and Rj is a 6-membered aromatic ring is the same as those described for A1 and A2 in the general formula (1).
  • the aromatic hydrocarbon ring L 2 represents an aromatic heterocyclic ring, the alkyl groups are the same as those mentioned L of each of the general formula (1).
  • Ar represents carbazole, dibenzofuran, azadibenzofuran, dibenzothiophene, azadibenzothiophene, azacarbazole, naphthalene, anthracene, phenanthrene or fluorene.
  • Rk represents a hydrogen atom or a substituent. At least two of Rk represent a 6-membered aromatic heterocycle, and the 6-membered aromatic heterocycle may be condensed.
  • n3 represents an integer of 2 or more.
  • the substituent represented by Rk is the same as the substituent represented by Ra, Rb and Rc in the general formula (2). Further, the 6-membered aromatic heterocycle represented by Rk is the same as that described for A1 and A2 in the general formula (1).
  • Y 1 and Y 2 represent O, S, and NR 1 .
  • X 1 to X 16 represent CR 2 or N. At least two of X 1 to X 16 represent N.
  • L 1 represents a single bond, an aromatic hydrocarbon ring, an aromatic heterocyclic ring or an alkyl group.
  • R 1 and R 2 represent an aromatic hydrocarbon ring, an aromatic heterocyclic ring, or an alkyl group.
  • the aromatic hydrocarbon ring, aromatic heterocyclic ring and alkyl group represented by L 1 are the same as those described for L in the general formula (1).
  • the organic EL element 110 shown in FIG. 2 includes an anode 111, a first light emitting layer 119, an intermediate connector layer 113, a second light emitting layer 123, and a cathode 115. These layers are stacked on the support substrate 116. Details of these components will be described later.
  • an anode 111 is formed on a support substrate 116, and a first light emitting unit 112 having a first light emitting layer 119 is formed on the anode 111. Further, an intermediate connector layer 113 is formed on the first light emitting unit 112, and a second light emitting unit 114 having the second light emitting layer 123 is formed on the intermediate connector layer 113. Further, a cathode 115 is formed on the second light emitting unit 114.
  • the organic EL element 110 has a configuration in which the anode 111 is formed of a transparent electrode, the cathode 115 functions as a reflective electrode, and light is extracted from the support substrate 116 side, that is, a so-called bottom emission type configuration. In addition, it has a so-called tandem configuration in which the first light emitting unit 112 and the second light emitting unit 114 are stacked via the intermediate connector layer 113.
  • the anode 111 is configured by a reflective electrode and the cathode 115 functions as a transparent electrode.
  • Light is extracted from the cathode 115 side, that is, a so-called top emission type. It may be configured to include electrodes and have a configuration in which the cathode 115 functions as a transparent electrode, and a transparent configuration in which light is extracted from the support substrate 116 side and the cathode 115 side.
  • the first light emitting unit 112 and the second light emitting unit 114 have at least one light emitting layer or the like containing a light emitting organic material.
  • an intermediate connector layer is provided between the first light emitting layer provided in the first light emitting unit and the second light emitting layer provided in the second light emitting unit. Then, the intermediate connector layer contains the alkali metal or the alkaline earth metal described above, and the intermediate connector layer (specifically, a charge generation layer) or between the intermediate connector layer and the first light emitting layer. (Specifically, the first electron transport layer) contains a compound having a structure represented by the general formula (1).
  • the intermediate connector layer may contain an alkali metal, an alkaline earth metal, or a compound other than the compound having the structure represented by the general formula (1).
  • the intermediate connector layer is a layer having an interface with an organic compound layer that electrically connects a plurality of light emitting units in series in an electric field.
  • an organic compound or an inorganic compound can be used alone or in combination of two or more.
  • the intermediate connector layer is formed of at least one or more layers, preferably two or more layers, and particularly preferably includes one or both of a p-type semiconductor layer and an n-type semiconductor layer.
  • a bipolar layer that can generate and transport holes and electrons inside the layer by an external electric field may be used.
  • metals, metal oxides, and alloys thereof that can be used as ordinary electrode materials can be suitably used.
  • the intermediate connector layer may have a charge generation layer configuration having a function of injecting electrons into one light emitting unit and a function of injecting holes into the other light emitting unit.
  • the intermediate connector layer can be formed using the same material as the anode and the cathode. Further, the intermediate connector layer can be formed using a material having lower conductivity than the anode and the cathode.
  • an insulator or a semiconductor such as lithium oxide, lithium fluoride, and cesium carbonate can be used as a layer having a function of injecting electrons.
  • a material in which an electron-donating substance is added to a substance having a high electron-transport property can be used.
  • Examples of the organic compound include a nanocarbon material, an organic metal complex compound that functions as an organic semiconductor material (organic acceptor, organic donor), an organic salt, an aromatic hydrocarbon compound, and a derivative thereof, a heteroaromatic hydrocarbon compound, and a derivative thereof. And the like.
  • Examples of the inorganic compound include a metal, an inorganic oxide, and an inorganic salt.
  • Examples of the substance having a high electron transporting property include tris (4-methyl-8-quinolinolato) aluminum (abbreviation: Almq 3 ), bis (10-hydroxybenzo [h] quinolinato) beryllium (abbreviation: BeBq 2 ), and bis ( A metal complex having a quinoline skeleton or a benzoquinoline skeleton such as 2-methyl-8-quinolinolato) (4-phenylphenolato) aluminum (abbreviation: BAlq) can be used.
  • Almq 3 tris (4-methyl-8-quinolinolato) aluminum
  • BeBq 2 bis (10-hydroxybenzo [h] quinolinato) beryllium
  • BAlq A metal complex having a quinoline skeleton or a benzoquinoline skeleton such as 2-methyl-8-quinolinolato) (4-phenylphenolato) aluminum
  • bis [2- (2-hydroxyphenyl) benzoxazolat] zinc (abbreviation: Zn (BOX) 2
  • bis [2- (2-hydroxyphenyl) benzothiazolato] zinc (abbreviation: Zn ( Metal complexes having an oxazole-based or thiazole-based ligand such as BTZ) 2 )
  • Zn Metal complexes having an oxazole-based or thiazole-based ligand such as BTZ
  • 2- (4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis [5- (P-tert-butylphenyl) -1,3,4-oxadiazol-2-yl] benzene (abbreviation: OXD-7), 3- (4-biphenylyl) -4-phenyl-5- (4-tert -Butylphenyl) -1,2,4-triazole (abbreviation: TAZ), bathocuproine (abbreviation: BCP) and the like can also be used.
  • PBD 4,4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole
  • OXD-7 1,3-bis [5- (P-tert-butylphenyl) -1,3,4-oxadiazol-2-yl] benzene
  • the above substance having a high electron-transport property mainly has an electron mobility of 10 ⁇ 6 cm 2 / V ⁇ s or more. Note that a substance other than the above substances can be used as long as the substance has a property of transporting more electrons than holes.
  • an electron-donating substance By adding an electron-donating substance to a substance having a high electron-transport property, the electron-injection property can be improved. Therefore, the driving voltage of the light emitting element can be reduced.
  • an alkali metal an alkaline earth metal, a rare earth metal, a metal belonging to Group 13 of the periodic table, an oxide thereof, or a carbonate thereof can be used.
  • an organic compound such as tetrathianaphthacene may be used as the donor substance.
  • a layer having a function of injecting holes in the intermediate connector layer for example, a semiconductor such as molybdenum oxide, vanadium oxide, rhenium oxide, ruthenium oxide, or an insulator can be used.
  • a material in which an electron-accepting substance is added to a substance having a high hole-transport property can be used.
  • a layer made of an electron accepting substance may be used.
  • NPB or ⁇ -NPD 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl
  • TPD N, N′-bis ( 3- Methylphenyl) -N, N'-diphenyl- [1,1'-biphenyl] -4,4'-diamine
  • TPD 4,4 ', 4 "-tris (N, N-diphenylamino) tri
  • aromatic amine compounds such as phenylamine (abbreviation: TDATA) and 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (abbreviation: MTDATA)
  • the above substance having a high hole-transport property is mainly a substance having a hole mobility of 10 ⁇ 6 cm 2 / V ⁇ s or more. Note that a substance other than the above substances may be used as long as the substance has a property of transporting more holes than electrons. Further, the above-described host material may be used.
  • the hole-injecting property can be increased. Therefore, the driving voltage of the light emitting element can be reduced.
  • the electron accepting substance 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloranil, or the like can be used.
  • F4-TCNQ 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane
  • chloranil or the like
  • a transition metal oxide can be used.
  • an oxide of a metal belonging to any of Groups 4 to 8 in the periodic table can be used.
  • vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide are preferable because of their high electron-accepting properties.
  • molybdenum oxide is particularly preferable because it is stable in the air, has low hygroscopicity, and is easy to handle.
  • another layer may be introduced between the layer having a function of injecting holes and the layer having a function of injecting electrons, if necessary.
  • a conductive layer such as ITO or an electronic relay layer may be provided.
  • the electron relay layer has a function of reducing voltage loss generated between a layer having a function of injecting holes and a layer having a function of injecting electrons.
  • PTCDA 3,4,9,10-perylenetetracarboxylic dianhydride
  • PTCBI 3,4,9,10-perylenetetracarboxylic bisbenzimidazole
  • the first light emitting unit 112 is provided between the anode 111 and the intermediate connector layer 113, and the second light emitting unit 112 is provided between the intermediate connector layer 113 and the cathode 115.
  • the first light emitting unit 112 includes at least a first light emitting layer 119 including an organic material having a light emitting property
  • the second light emitting unit 114 includes at least a second light emitting layer 123 including an organic material having a light emitting property.
  • the first light emitting unit 112 and the second light emitting unit 114 the first light emitting layer 119 and the anode 111, the first light emitting layer 119 and the intermediate connector layer 113, the intermediate connector layer 113 and the cathode 115 Another layer may be provided between them.
  • first light emitting unit 112 and the second light emitting unit 114 will be collectively described as a light emitting unit, and the first light emitting layer 119 provided in the first light emitting unit 112 and the second light emitting provided in the second light emitting unit 114 will be described.
  • the layer 123 will be described and described collectively as a light emitting layer.
  • Typical element configurations of the light-emitting unit include, but are not limited to, the following configurations. (1) hole injection / transport layer / light emitting layer / electron injection / transport layer (2) hole injection / transport layer / light emitting layer / hole blocking layer / electron injection / transport layer (3) hole injection / transport layer / electron blocking layer / Emission layer / hole blocking layer / electron injection / transport layer (4) hole injection layer / hole transport layer / emission layer / electron transport layer / electron injection layer (5) hole injection layer / hole transport layer / emission layer / Hole blocking layer / electron transport layer / electron injection layer (6) hole injection layer / hole transport layer / electron blocking layer / emission layer / hole blocking layer / electron transport layer / electron injection layer (7) hole Injection layer / Hole transport layer / Emitting layer / Electron transport layer
  • the configuration (7) is particularly preferable.
  • the anode 111 / first light emitting unit first positive Hole injection layer 117 / first hole transport layer 118 / first light emitting layer 119 / first electron transport layer 120
  • 112 / intermediate connector layer 113 / second light emitting unit second hole injection layer 121 / second hole.
  • Transport layer 122 / second light emitting layer 123 / second electron transport layer 124) 114 / cathode 115.
  • the anode / first light emitting unit (first hole injection layer / first hole transport layer / first light emitting layer / first electron transport) Layer / first electron injection layer) / intermediate connector layer / second light emitting unit (second hole injection layer / second hole transport layer / second light emitting layer / second electron transport layer / second electron injection layer) / And a cathode.
  • the light-emitting layer includes a single layer or a plurality of layers.
  • the electron transport layer is a layer having a function of transporting electrons.
  • the electron transport layer broadly includes an electron injection layer and a hole blocking layer.
  • the electron transport layer may be composed of a plurality of layers.
  • the hole transport layer is a layer having a function of transporting holes.
  • the hole transport layer broadly includes a hole injection layer and an electron blocking layer. Further, the hole transport layer may be composed of a plurality of layers.
  • a phosphorescent material and a fluorescent material may be mixed in the light-emitting layer in the light-emitting unit, but it is preferable that the light-emitting unit is composed of only the phosphorescent material or the fluorescent material.
  • the fluorescent light emitting layer and the phosphorescent light emitting layer are preferably host and dopant type light emitting layers. Further, the light emitting dopant contained in the light emitting layer may be contained at a uniform concentration in the thickness direction of the light emitting layer, or may have a concentration distribution.
  • each light emitting unit has the same layer structure except for a light-emitting layer.
  • each light emitting unit preferably has the same number of light emitting layers.
  • the vapor deposition process has an advantage in terms of production efficiency such that a film forming chamber can be commonly used for each light emitting unit.
  • white light emission is to be obtained by stacking light-emitting units that emit light of different colors
  • these light-emitting units have a complementary color relationship with each other.
  • a blue light-emitting unit and a light-emitting unit that emits a complementary color of yellow-green, yellow, or orange an organic EL element that emits white light can be obtained.
  • the “complementary color” relationship refers to a relationship between colors that become achromatic when mixed. That is, white light emission can be obtained by mixing light emission of substances emitting light of complementary colors.
  • a layer exhibiting green and red light-emitting colors is provided in one of the light-emitting units. Is preferred.
  • blue, green, and red light-emitting materials may be mixed in one light-emitting layer and provided in the light-emitting unit as a light-emitting layer that emits white light.
  • each layer included in each light emitting unit is not particularly limited. It is preferable to adjust the film thickness in the range of 5 to 200 nm from the viewpoints of homogeneity of the film to be formed, application of unnecessary high voltage at the time of light emission, and improvement of stability of emission color with respect to drive current. It is more preferably adjusted to the range of 10 to 100 nm or less.
  • the method for forming the individual layers included in each light emitting unit is not particularly limited as long as it is a method capable of forming a thin film.
  • a vapor deposition method, a sputtering method, a wet process (a spin coating method, a casting method, an inkjet method, an LB method) Method, spray method, printing method, slot type coater method) and the like.
  • a vacuum deposition method, a spin coating method, an ink jet method, a printing method, and a slot type coater method are particularly preferable because a lower layer is less damaged and a uniform film without pinholes is easily obtained.
  • the light emitting layer according to the present invention is a layer in which electrons and holes injected from an electrode or an electron transport layer and a hole transport layer are recombined to emit light, and a light emitting portion is in the light emitting layer. May be the interface between the light emitting layer and the adjacent layer.
  • the total sum of the thicknesses of the light emitting layers is not particularly limited, but from the viewpoint of uniformity of the film and prevention of applying an unnecessary high voltage at the time of light emission, and from the viewpoint of improving the stability of the emission color with respect to the drive current, It is preferably adjusted to a range of 2 nm to 5 ⁇ m, more preferably adjusted to a range of 2 to 200 nm, and particularly preferably adjusted to a range of 5 to 100 nm.
  • the light-emitting layer is prepared by using a light-emitting dopant or a host compound described below, for example, a vacuum deposition method, a wet method (also called a wet process, for example, a spin coating method, a casting method, a die coating method, a blade coating method, a roll coating method). And an ink-jet method, a printing method, a spray coating method, a curtain coating method, an LB method (Langmuir Blodgett method), and the like.
  • the light emitting layer of the organic EL device of the present invention preferably contains a light emitting dopant (such as a phosphorescent light emitting dopant or a fluorescent light emitting dopant) compound and a host compound.
  • Luminescent dopant (also referred to as a luminescent dopant, a dopant compound, or simply a dopant) Will be described.
  • the luminescent dopant include a fluorescent dopant (also referred to as a fluorescent dopant, a fluorescent compound, and a fluorescent compound), and a phosphorescent dopant (also referred to as a phosphorescent dopant, a phosphorescent compound, a phosphorescent compound, and the like). .) Can be used.
  • a phosphorescent dopant is a compound that emits light from an excited triplet, and specifically, a compound that emits phosphorescent light at room temperature (25 ° C.), and has a phosphorescent quantum yield. Is defined as a compound having a value of 0.01 or more at 25 ° C., and a preferable phosphorescence quantum yield is 0.1 or more.
  • the phosphorescence quantum yield can be measured by the method described in Spectroscopy II, 4th Edition, pp. 398 (1992 edition, Maruzen) of Experimental Chemistry Course 7.
  • the phosphorescent dopant used in the present invention achieves the above-mentioned phosphorescence quantum yield (0.01 or more) in any of the solvents. Just do it.
  • the phosphorescent dopant emits two kinds of light.
  • One is that the recombination of carriers occurs on the host compound to which the carrier is transported, and the excited state of the light emitting host compound is generated. This energy is transferred to the phosphorescent dopant.
  • This is an energy transfer type in which light is emitted from a phosphorescent dopant by being moved.
  • the other is a carrier trap type in which a phosphorescent dopant acts as a carrier trap, carriers recombine on the phosphorescent dopant, and light emission from the phosphorescent dopant is obtained. In either case, the condition is that the excited state energy of the phosphorescent dopant is lower than the excited state energy of the host compound.
  • Fluorescent dopant As the fluorescent dopant, coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squarium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes, Examples include perylene dyes, stilbene dyes, polythiophene dyes, rare earth complex fluorescent materials, and compounds having a high fluorescence quantum yield represented by laser dyes.
  • the light emitting dopant used in the present invention may be used in combination of plural kinds of compounds, or may be used in combination of phosphorescent dopants having different structures or in combination of phosphorescent dopant and fluorescent dopant.
  • the luminescent dopant conventionally known compounds described in WO 2013/061850 can be suitably used, but the present invention is not limited thereto.
  • the host compound (also referred to as a light-emitting host or light-emitting host compound) that can be used in the present invention has a mass ratio in the layer of 20% or more among the compounds contained in the light-emitting layer. It is defined as a compound having a phosphorescence quantum yield of phosphorescence at room temperature (25 ° C.) of less than 0.1. Preferably, the phosphorescence quantum yield is less than 0.01. Further, among the compounds contained in the light emitting layer, the mass ratio in the layer is preferably 20% or more.
  • the host compound that can be used in the present invention is not particularly limited, and a compound that is conventionally used in an organic EL device can be used.
  • a compound that is conventionally used in an organic EL device can be used.
  • those having a basic skeleton such as a carbazole derivative, a triarylamine derivative, an aromatic derivative, a nitrogen-containing heterocyclic compound, a thiophene derivative, a furan derivative, an oligoarylene compound, or a carboline derivative or a diazacarbazole derivative (here Wherein the diazacarbazole derivative is one in which at least one carbon atom of a hydrocarbon ring constituting a carboline ring of the carboline derivative is substituted with a nitrogen atom.
  • a compound that has a hole transporting ability and an electron transporting ability, prevents a longer wavelength of light emission, and has a high Tg (glass transition temperature) is preferable.
  • a conventionally known host compound may be used alone or in combination of two or more. By using a plurality of host compounds, charge transfer can be adjusted, and the efficiency of the organic EL device can be increased. In addition, by using a plurality of conventionally known compounds, it is possible to mix different luminescence, and thus, it is possible to obtain an arbitrary luminescence color.
  • the host compound used in the present invention may be a low molecular compound, a high molecular compound having a repeating unit, or a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (polymerizable host compound). One or more of such compounds may be used.
  • the known host compound include the compounds described in the following documents. JP-A-2001-257076, JP-A-2002-308855, JP-A-2001-313179, JP-A-2002-319493, JP-A-2001-357977, JP-A-2002-334786, JP-A-2002-8860, JP-A-2002-334787, JP-A-2002-15871, JP-A-2002-334788, JP-A-2002-43056, JP-A-2002-334789, JP-A-2002-75645, JP-A-2002-338579, and JP-A-2002-338579.
  • JP-A-2002-105445 JP-A-2002-343568, JP-A-2002-141173, JP-A-2002-352957, JP-A-2002-203683, JP-A-2002-363227, JP-A-2002-231453, and JP-A-2002-231453.
  • cathode As the cathode, a metal having a low work function (4 eV or less) (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof are used as an electrode material. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al 2 O) 3 ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like.
  • a mixture of an electron-injecting metal and a second metal that is a stable metal having a large work function value such as a magnesium / silver mixture
  • a magnesium / aluminum mixture a magnesium / indium mixture
  • an aluminum / aluminum oxide (Al 2 O 3 ) mixture a lithium / aluminum mixture, aluminum and the like.
  • silver is a main component
  • an alloy containing silver as a main component is, for example, silver magnesium (AgMg), silver copper (AgCu), silver palladium (AgPd), silver palladium copper (AgPdCu).
  • the “main component” in the present invention means that the content is 50% by mass or more in the film or layer, preferably 80% by mass or more, more preferably 90% by mass or more. .
  • the cathode using an alloy containing silver as a main component may have a configuration in which the cathode is divided into a plurality of layers and stacked as necessary.
  • the thickness of the cathode is selected in the range of usually 10 nm to 5 ⁇ m, preferably 50 to 200 nm. When an alloy containing silver as a main component is used, the thickness is preferably 15 nm or less, and more preferably in the range of 4 to 12 nm. When the film thickness is within the above range, components of light absorbed or reflected by the film can be reduced, light transmittance can be maintained, and conductivity of the layer can be secured.
  • the cathode when the cathode contains silver as a main component, the cathode is preferably adjacent to the organic functional layer containing the compound having the structure represented by the general formula (1).
  • the organic functional layer containing the compound having the structure represented by the general formula (1) is preferably adjacent to the cathode, and even when the cathode is formed on the organic functional layer, The organic functional layer may be formed. Further, the cathode may be formed on the organic functional layer, the organic functional layer may be further formed on the cathode, and the cathode may be sandwiched between two organic functional layers.
  • a compound having a structure represented by the general formula (1) in which silver atoms constituting the cathode are contained in the metal affinity layer is used.
  • the interaction causes the diffusion distance of silver atoms on the surface of the organic functional layer to be reduced, so that aggregation (migration) of silver at a specific portion can be suppressed. That is, a silver atom forms a two-dimensional nucleus on the surface of an organic functional layer having an atom having an affinity for a silver atom, and forms a two-dimensional single crystal layer around the nucleus.
  • a film is formed by a Frank-van der Merwe (FM type) film growth.
  • the cathode can be manufactured by forming a thin film of a general electrode material other than an alloy containing silver as a main component by a method such as evaporation or sputtering.
  • the sheet resistance value of the cathode is several hundred ⁇ / sq. Or less, particularly preferably 25 ⁇ or less.
  • one of the anode and the cathode of the organic EL element is transparent or translucent, thereby improving emission luminance.
  • the light transmittance of the cathode is preferably 50% or more. preferable.
  • a transparent or translucent cathode can be manufactured by forming the above metal on the cathode in a thickness of 1 to 20 nm and then manufacturing a conductive transparent material mentioned in the description of the anode later. By applying this, an element in which both the anode and the cathode have transparency can be manufactured.
  • the electron transport layer is made of a material having a function of transporting electrons.
  • the first electron transport layer which is a layer between the intermediate connector layer and the first light emitting layer, contains a compound having a structure represented by the general formula (1).
  • an electron injection layer and a hole blocking layer are also included in the electron transport layer.
  • the electron transport layer can be provided with a single layer or a plurality of layers. Further, an electron injection / transport layer that also contains a material included in the electron injection layer described below may be provided.
  • the electron transporting layer only needs to have a function of transmitting electrons injected from the cathode to the light emitting layer.
  • any one of conventionally known compounds may be selected and used in combination. Is also possible.
  • electron transport materials examples include polycyclic aromatic hydrocarbons such as nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, and naphthalene perylene; Heterocyclic tetracarboxylic anhydride, carbodiimide, fluorenylidenemethane derivative, anthraquinodimethane and anthrone derivative, oxadiazole derivative, carboline derivative, or carbon atom of a hydrocarbon ring constituting a carboline ring of the carboline derivative Derivatives having a ring structure in which at least one is substituted by a nitrogen atom, hexaazatriphenylene derivatives, and the like.
  • polycyclic aromatic hydrocarbons such as nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, and naphthalene perylene
  • a thiadiazole derivative in which an oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron-withdrawing group can also be used as the electron transport material.
  • Polymer materials in which these materials are introduced into a polymer chain, or in which these materials are used as a polymer main chain, can also be used.
  • metal complexes of 8-quinolinol derivatives for example, tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum, tris (2-methyl-8-quinolinol) Aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), etc., and the central metal of these metal complexes are placed on In, Mg, Cu, Ca, Sn, Ga or Pb. Altered metal complexes can also be used as electron transport materials.
  • metal-free or metal phthalocyanine or those whose terminals are substituted with an alkyl group, a sulfonic acid group, or the like, can also be used as the electron transporting material.
  • an inorganic semiconductor such as n-type Si or n-type SiC can also be used as the electron transporting material.
  • the electron transport layer is formed by depositing an electron transport material by, for example, a vacuum deposition method, a wet method (also referred to as a wet process, for example, a spin coating method, a casting method, a die coating method, a blade coating method, a roll coating method, an ink jet method, a printing method, a spraying method). It is preferable to form the thin film by a coating method, a curtain coating method, an LB method (including a Langmuir-Blodgett method), or the like.
  • the thickness of the electron transport layer is not particularly limited, but is usually about 5 to 5000 nm, preferably 5 to 200 nm.
  • the electron transport layer may have a single-layer structure composed of one or more of the above materials.
  • an n-type dopant such as a metal compound such as a metal complex and a metal halide may be doped.
  • Injection layer electron injection layer (cathode buffer layer), hole injection layer
  • the injection layer is provided as needed, and has an electron injection layer and a hole injection layer, and may be present between the anode and the light emitting layer or the hole transport layer and between the cathode and the light emitting layer or the electron transport layer.
  • the injection layer is a layer provided between an electrode and an organic functional layer for lowering driving voltage and improving light emission luminance, and is referred to as “organic EL device and the forefront of its industrialization (NTS, November 30, 1998). Issue 2), Vol. 2, Chapter 2, “Electrode Materials” (pages 123 to 166), which includes a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer).
  • anode buffer layer hole injection layer
  • Representative phthalocyanine buffer layer, hexaazatriphenylene derivative buffer layer described in JP-T-2003-519432 and JP-A-2006-135145, oxide buffer layer represented by vanadium oxide, amorphous carbon Examples include a buffer layer, a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) and polythiophene, and an orthometalated complex layer represented by a tris (2-phenylpyridine) iridium complex.
  • cathode buffer layer (electron injection layer)
  • a metal buffer layer such as lithium fluoride and potassium fluoride, an alkaline earth metal compound buffer layer such as magnesium fluoride and cesium fluoride, and an aluminum oxide. Oxide buffer layers and the like.
  • the buffer layer (injection layer) is desirably an extremely thin film, and the thickness is preferably in the range of 0.1 nm to 5 ⁇ m, depending on the material.
  • Blocking layer hole blocking layer, electron blocking layer
  • the blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film as described above. For example, it is described in JP-A-11-204258 and JP-A-11-204359, and page 237 of "Organic EL Devices and Their Forefront of Industrialization (published by NTT Corporation on November 30, 1998)". There is a hole blocking (hole block) layer.
  • the hole blocking layer has a function of an electron transport layer in a broad sense, and is made of a hole blocking material having an extremely small ability to transport holes while having a function of transporting electrons. , The probability of recombination of electrons and holes can be improved.
  • the above-described structure of the electron transport layer can be used as a hole blocking layer, if necessary.
  • the hole blocking layer of the organic EL device of the present invention is preferably provided adjacent to the light emitting layer.
  • a carbazole derivative, a carboline derivative, or a diazacarbazole derivative (here, a diazacarbazole derivative is one in which one of carbon atoms constituting a carboline ring is a nitrogen atom) Is preferable.).
  • the electron blocking layer has a function of a hole transport layer in a broad sense, and is made of a material having a function of transporting holes and having an extremely small ability to transport electrons. Blocking can improve the probability of recombination of electrons and holes.
  • the configuration of the hole transport layer described below can be used as an electron blocking layer as needed.
  • the layer thickness of the hole blocking layer and the electron transporting layer according to the present invention is preferably in the range of 3 to 100 nm, and more preferably in the range of 5 to 30 nm.
  • the hole transport layer is made of a hole transport material having a function of transporting holes.
  • a hole injection layer and an electron blocking layer are also included in the hole transport layer.
  • the hole transport layer can be provided as a single layer or a plurality of layers.
  • the hole transporting material has any of hole injection or transport and electron barrier properties, and may be any of an organic substance and an inorganic substance.
  • triazole derivatives for example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives,
  • Examples include a stilbene derivative, a silazane derivative, an aniline-based copolymer, a conductive polymer oligomer, particularly a thiophene oligomer.
  • azatriphenylene derivatives described in JP-T-2003-519432, JP-A-2006-135145, and the like can also be used as the hole transport material.
  • the hole transporting material those described above can be used, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound.
  • aromatic tertiary amine compound and styrylamine compound include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl; N, N'-diphenyl-N, N'- Bis (3-methylphenyl)-[1,1'-biphenyl] -4,4'-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ', N'-tetra-p-tolyl-4,4'-diaminobiphenyl; 1,1-bis (4-di-
  • a polymer material in which these materials are introduced into a polymer chain or a polymer material in which these materials are used as a polymer main chain, can also be used.
  • inorganic compounds such as p-type Si and p-type SiC can also be used as the hole injection material and the hole transport material.
  • JP-A-11-251067, J.P. Huang @ et. al. A so-called p-type hole transport material as described in a well-known document (Applied Physics Letters 80 (2002), p. 139) can also be used. In the invention, it is preferable to use these materials since a light emitting element with higher efficiency can be obtained.
  • the hole transport layer can be formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an inkjet method, and an LB method. it can.
  • the layer thickness of the hole transport layer is not particularly limited, but is usually about 5 nm to 5 ⁇ m, preferably 5 to 200 nm.
  • the hole transport layer may have a one-layer structure composed of one or more of the above materials.
  • a hole transporting layer having a high p property and doped with an impurity may be used.
  • Examples thereof include JP-A-4-297076, JP-A-2000-196140, JP-A-2001-102175, and J.P. Appl. Phys. , 95, 5773 (2004).
  • anode As the anode in the organic EL element, a metal, an alloy, an electrically conductive compound, or a mixture thereof having a large work function (4 eV or more) as an electrode material is preferably used.
  • an electrode material include metals such as Au and conductive transparent materials such as CuI, ITO, SnO 2 , and ZnO.
  • a material such as IDIXO (In 2 O 3 —ZnO) which can form an amorphous and transparent conductive film may be used.
  • the anode may form a thin film by a method such as vapor deposition or sputtering of these electrode substances and form a pattern of a desired shape by a photolithography method, or when the pattern precision is not required much (about 100 ⁇ m or more).
  • a pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material.
  • a wet film forming method such as a printing method and a coating method can be used.
  • the light transmittance is greater than 10%, and the sheet resistance of the anode is several hundred ⁇ / sq.
  • the thickness depends on the material, but is usually selected in the range of 10 to 1000 nm, preferably 10 to 200 nm.
  • the support substrate (hereinafter, also referred to as a base, a substrate, a base, a support, or the like) that can be used in the organic EL device of the present invention is not particularly limited in the type of glass, plastic, and the like, and is transparent. Or opaque. When light is extracted from the support substrate side, the support substrate is preferably transparent. Preferred examples of the transparent support substrate include glass, quartz, and a transparent resin film. A particularly preferred support substrate is a resin film that can provide flexibility to the organic EL element.
  • the resin film examples include polyester such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate (TAC), cellulose acetate butyrate, and cellulose acetate propionate ( CAP), cellulose esters such as cellulose acetate phthalate and cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyetherketone, polyimide , Polyether sulfone (PES), polyphenylene sulfide, polysulfones Polyetherimide, polyetherketoneimide, polyamide, fluororesin, nylon, polymethylmethacrylate, acrylic or polyarylates, cycloolefin-based resins such as ARTON (trade name, manufactured by JSR) or
  • An inorganic or organic coating or a hybrid coating of both may be formed on the surface of the resin film, and the water vapor permeability (25 ⁇ 0.5 ° C.) measured by a method according to JIS K 7129-1992. , Relative humidity (90 ⁇ 2)%) of 0.01 g / m 2 ⁇ 24 h or less, and furthermore, oxygen permeability measured by a method according to JIS K 7126-1987. There, 1 ⁇ 10 -3 mL / m 2 ⁇ 24h ⁇ atm or less, the water vapor permeability is preferably 1 ⁇ 10 -5 g / m 2 ⁇ 24h or less high gas barrier film.
  • any material may be used as long as it has a function of suppressing intrusion of a substance that causes deterioration of the element such as moisture and oxygen, and examples thereof include silicon oxide, silicon dioxide, and silicon nitride. .
  • the order of laminating the inorganic layer and the organic functional layer is not particularly limited, but it is preferable that both layers are alternately laminated plural times.
  • the method of forming the gas barrier layer includes a vacuum deposition method, a sputtering method, a reactive sputtering method, a molecular beam epitaxy method, a cluster ion beam method, an ion plating method, a plasma polymerization method, and an atmospheric pressure plasma weight method.
  • a legal method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, and the like can be used, a method based on an atmospheric pressure plasma polymerization method described in JP-A-2004-68143 is particularly preferable.
  • the opaque support substrate include a metal plate such as aluminum and stainless steel, a film, an opaque resin substrate, and a ceramic substrate.
  • the external extraction yield at room temperature of the light emission of the organic EL device of the present invention is preferably 1% or more, more preferably 5% or more.
  • the external extraction quantum yield (%) the number of photons emitted to the outside of the organic EL element / the number of electrons flowing to the organic EL element ⁇ 100.
  • a hue improving filter such as a color filter may be used in combination, or a color conversion filter that converts the emission color of the organic EL element into multiple colors using a phosphor may be used in combination.
  • ⁇ max of light emission of the organic EL element is preferably 480 nm or less.
  • anode / first light emitting unit (hole injection layer / hole transport layer / first light emitting layer / electron transport layer) / intermediate connector layer / second light emitting unit (hole injection layer)
  • a method for manufacturing an element consisting of / hole transport layer / first light emitting layer / electron transport layer) / cathode will be described.
  • a thin film made of a desired electrode material for example, a material for an anode, is formed on an appropriate substrate so as to have a thickness of 1 ⁇ m or less, preferably 10 to 200 nm, to produce an anode.
  • a first light-emitting unit (a hole injection layer, a hole transport layer, a first light-emitting layer, and an electron transport layer), an intermediate connector layer, and a second light-emitting unit (a hole injection layer, A thin film containing an organic compound such as a hole transport layer, a first light emitting layer, and an electron transport layer is formed.
  • a thin film can be formed by a vacuum evaporation method, a wet method (also referred to as a wet process), or the like.
  • Wet methods include spin coating, casting, die coating, blade coating, roll coating, ink-jet printing, printing, spray coating, curtain coating, LB coating, etc., but precise thin films can be formed.
  • a method having high suitability for a roll-to-roll method such as a die coating method, a roll coating method, an ink jet method, and a spray coating method is preferable.
  • a different film formation method may be applied to each layer.
  • liquid medium for dissolving or dispersing the organic EL material such as the luminescent dopant used in the present invention examples include, for example, methyl ethyl ketone, ketones such as cyclohexanone, fatty acid esters such as ethyl acetate, halogenated hydrocarbons such as dichlorobenzene, Aromatic hydrocarbons such as toluene, xylene, mesitylene and cyclohexylbenzene, aliphatic hydrocarbons such as cyclohexane, decalin and dodecane, and organic solvents such as dimethylformamide (DMF) and DMSO can be used.
  • dispersing can be performed by a dispersing method such as ultrasonic wave, high shear force dispersion and media dispersion.
  • a thin film made of a material for a cathode is formed thereon to a thickness of 1 ⁇ m or less, preferably in a range of 50 to 200 nm, and a desired organic EL element can be obtained by providing a cathode.
  • the cathode / second light emitting unit (electron transport layer / second light emitting layer / hole transport layer / hole injection layer) / intermediate connector layer / first light emitting unit (electron transport layer / first A light-emitting layer / a hole-transporting layer / a hole-injecting layer) / anode can be formed in this order.
  • the organic EL element of the present invention is manufactured from the hole injection layer to the cathode consistently by one evacuation, but it may be taken out in the middle and subjected to a different film formation method. At that time, it is preferable to perform the operation under a dry inert gas atmosphere.
  • sealing means used in the present invention include a method of bonding a sealing member, an electrode, and a support substrate with an adhesive.
  • the sealing member only needs to be disposed so as to cover the display area of the organic EL element, and may have a concave plate shape or a flat plate shape.
  • the transparency and the electrical insulation are not particularly limited.
  • Specific examples include a glass plate, a polymer plate / film, and a metal plate / film.
  • the glass plate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz.
  • the polymer plate include those formed from polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, polysulfone, and the like.
  • Examples of the metal plate include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium, and tantalum.
  • a polymer film or a metal film can be preferably used because the element can be thinned.
  • the polymer film is measured by the oxygen permeability measured by the method based on JIS K 7126-1987 is 1 ⁇ 10 -3 mL / m 2 ⁇ 24h ⁇ atm or less, in conformity with JIS K 7129-1992 method is water vapor transmission rate (25 ⁇ 0.5 ° C., relative humidity (90 ⁇ 2)%) is preferably one of the following 1 ⁇ 10 -3 g / m 2 ⁇ 24h.
  • sand blasting, chemical etching, or the like is used to process the sealing member into a concave shape.
  • the adhesive examples include an acrylic acid-based oligomer, a photocurable and thermosetting adhesive having a reactive vinyl group of a methacrylic acid-based oligomer, and a moisture-curable adhesive such as 2-cyanoacrylate. be able to.
  • a heat and chemical curing type (two-liquid mixing) of an epoxy type or the like can be used.
  • hot melt type polyamide, polyester, and polyolefin can be used.
  • a cationic curing type ultraviolet curing epoxy resin adhesive can be used.
  • the organic EL element may be deteriorated by the heat treatment, it is preferable that the organic EL element can be adhesively cured from room temperature to 80 ° C. Further, a desiccant may be dispersed in the adhesive.
  • the application of the adhesive to the sealing portion may be performed by using a commercially available dispenser or by printing such as screen printing.
  • the sealing film by coating the electrode and the light emitting unit on the outside of the electrode on the side facing the support substrate with the light emitting unit interposed therebetween, and forming an inorganic or organic material layer in contact with the support substrate.
  • the material for forming the film may be any material having a function of suppressing intrusion of elements that cause deterioration of the element such as moisture or oxygen, and for example, silicon oxide, silicon dioxide, silicon nitride, or the like may be used. it can.
  • the method for forming these films is not particularly limited, and examples thereof include a vacuum deposition method, a sputtering method, a reactive sputtering method, a molecular beam epitaxy method, a cluster ion beam method, an ion plating method, a plasma polymerization method, and an atmospheric pressure plasma.
  • a polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.
  • an inert gas such as nitrogen or argon, or an inert liquid such as fluorocarbon or silicone oil may be injected in a gas phase or a liquid phase.
  • an inert gas such as nitrogen or argon, or an inert liquid such as fluorocarbon or silicone oil may be injected in a gas phase or a liquid phase.
  • a vacuum it is also possible to use a vacuum.
  • a hygroscopic compound can be sealed inside.
  • Examples of the hygroscopic compound include metal oxides (eg, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide, etc.), sulfates (eg, sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate) Etc.), metal halides (eg, calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide, magnesium iodide, etc.), perchloric acids (eg, perchloric acid) Barium, magnesium perchlorate, etc.), and sulfates, metal halides and perchloric acids are preferably anhydrous salts.
  • metal oxides eg, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide, etc.
  • sulfates eg, sodium sulfate, calcium sulfate, magnesium sulf
  • a protective film or a protective plate may be provided outside the sealing film or the sealing film on the side facing the support substrate with the light emitting unit interposed therebetween in order to increase the mechanical strength of the element.
  • the mechanical strength is not always high. Therefore, it is preferable to provide such a protective film and a protective plate.
  • a glass plate, a polymer plate / film, a metal plate / film, etc. similar to those used for the sealing can be used. It is preferable to use
  • the organic EL element emits light inside a layer having a higher refractive index than air (having a refractive index of about 1.7 to 2.1), and can extract only about 15 to 20% of the light generated in the light emitting layer. It is generally said. This is because light incident on the interface (the interface between the transparent substrate and air) at an angle ⁇ equal to or greater than the critical angle causes total reflection and cannot be taken out of the element, or the light between the transparent electrode or the light emitting layer and the transparent substrate. This is because light causes total reflection between them, and the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes toward the side surface of the element.
  • a method of improving the light extraction efficiency for example, a method of forming irregularities on the surface of a transparent substrate to prevent total reflection at an interface between the transparent substrate and air (US Pat. No. 4,774,435).
  • a method of improving efficiency by imparting light condensing properties to a substrate Japanese Patent Application Laid-Open No. 63-314795
  • a method of forming a reflective surface on a side surface of an element or the like Japanese Patent Application Laid-Open No. 1-220394
  • a method in which a flat layer having an intermediate refractive index is introduced between luminous bodies to form an antireflection film Japanese Patent Application Laid-Open No. 62-172691.
  • these methods can be used in combination with the organic EL device of the present invention.
  • a method of introducing a flat layer having a lower refractive index than the substrate between the substrate and the light-emitting body, or a method of introducing the transparent A method of forming a diffraction grating between any of the electrode layers and the light emitting layer (including between the substrate and the outside world) can be suitably used.
  • by combining these means it is possible to obtain an element having higher luminance or more excellent durability.
  • the low refractive index layer include aerogel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of a transparent substrate is generally about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.5 or less. Further, it is more preferably 1.35 or less. Also, the thickness of the low refractive index medium is desirably at least twice the wavelength in the medium. This is because the effect of the low-refractive-index layer is reduced when the thickness of the low-refractive-index medium becomes about the wavelength of light and the thickness of the electromagnetic wave oozing out by evanescent enters the substrate.
  • the method of introducing a diffraction grating into an interface that causes total reflection or any of the media is characterized in that the effect of improving light extraction efficiency is high.
  • This method utilizes the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction such as first-order diffraction and second-order diffraction, and it uses Light that cannot escape outside due to total reflection between layers is diffracted by introducing a diffraction grating in any layer or in a medium (in a transparent substrate or a transparent electrode) to diffract light. It is about to be taken out.
  • the diffraction grating to be introduced has a two-dimensional periodic refractive index. This is because light emitted from the light-emitting layer is randomly generated in all directions, so a general one-dimensional diffraction grating that has a periodic refractive index distribution only in a certain direction diffracts only light traveling in a specific direction. And light extraction efficiency does not increase so much. However, by making the refractive index distribution a two-dimensional distribution, light traveling in all directions is diffracted, and the light extraction efficiency is increased.
  • the position where the diffraction grating is introduced may be between any layers or in a medium (in a transparent substrate or a transparent electrode), but is preferably near the organic light emitting layer where light is generated.
  • the period of the diffraction grating is preferably about 1/2 to 3 times the wavelength of light in the medium.
  • the arrangement of the diffraction grating is preferably two-dimensionally repeated, such as a square lattice, a triangular lattice, a honeycomb lattice, or the like.
  • the organic EL element of the present invention is processed on the light extraction side of the substrate, for example, to provide a microlens array-like structure, or in combination with a so-called condensing sheet, in a specific direction, for example, with respect to the element light emitting surface.
  • a microlens array quadrangular pyramids having a side of 30 ⁇ m and an apex angle of 90 degrees are two-dimensionally arranged on the light extraction side of the substrate.
  • One side is preferably 10 to 100 ⁇ m. If it is smaller than this, the effect of diffraction occurs and coloring occurs, and if it is too large, the thickness becomes undesirably thick.
  • the condensing sheet for example, a sheet practically used in an LED backlight of a liquid crystal display device can be used.
  • a brightness enhancement film (BEF) manufactured by Sumitomo 3M Limited can be used.
  • BEF brightness enhancement film
  • the shape of the prism sheet for example, a ⁇ -shaped stripe having a vertex angle of 90 degrees and a pitch of 50 ⁇ m may be formed on the base material, or a shape in which the vertex angle is rounded, and the pitch is randomly changed. The shape may be a bent shape or another shape.
  • a light diffusing plate / film may be used in combination with the light collecting sheet.
  • a diffusion film (light-up) manufactured by Kimoto Co., Ltd. can be used.
  • the organic EL element of the present invention can be used as electronic devices, display devices, displays, and various light emitting devices.
  • Light emitting devices include, for example, lighting devices (home lighting, vehicle interior lighting), clocks and backlights for LCDs, signboard advertisements, traffic lights, light sources for optical storage media, light sources for electrophotographic copiers, light sources for optical communication processors, and light sources. Examples include, but are not limited to, light sources for sensors. In particular, it can be effectively used for a backlight of a liquid crystal display device and a light source for illumination.
  • patterning may be performed by a metal mask, an inkjet printing method, or the like at the time of film formation, if necessary.
  • patterning only the electrode may be patterned, or the electrode and the light emitting layer may be patterned. All layers of the element may be patterned, and a conventionally known method can be used for manufacturing the element.
  • the emission color of the organic EL device of the present invention or the compound of the present invention is shown in FIG. 7.16 on page 108 of “New Edition of Color Science Handbook” (edited by The Japan Society for Color Science, edited by The University of Tokyo Press, 1985). It is determined by the color when the result measured with a total CS-1000 (manufactured by Konica Minolta) is applied to the CIE chromaticity coordinates.
  • the organic EL element of the present invention is a white element
  • the organic EL element of the present invention can be used for a display device.
  • the display device may be single-color or multi-color, a multi-color display device will be described here.
  • a shadow mask is provided only when a light emitting layer is formed, and a film can be formed on one surface by an evaporation method, a casting method, a spin coating method, an inkjet method, a printing method, or the like.
  • the method is not particularly limited, but is preferably an evaporation method, an inkjet method, a spin coating method, or a printing method.
  • the configuration of the organic EL element included in the display device is selected from the above-described configuration examples of the organic EL element as necessary.
  • the method for manufacturing the organic EL element is as described in the above-described one embodiment of the method for manufacturing the organic EL element of the present invention.
  • a DC voltage is applied to the multicolor display device thus obtained, light emission can be observed by applying a voltage of about 2 to 40 V with the anode having a positive polarity and the cathode having a negative polarity. Also, even if a voltage is applied in the opposite polarity, no current flows and no light emission occurs. Further, when an AC voltage is applied, light is emitted only when the anode is in the positive state and the cathode is in the negative state.
  • the waveform of the applied AC may be arbitrary.
  • the multicolor display device can be used as a display device, a display, and various light emission light sources.
  • display devices and displays full-color display is possible by using three types of organic EL elements emitting blue, red, and green light.
  • the display device and the display include a television, a personal computer, a mobile device, an AV device, a teletext display, an information display in a car, and the like.
  • the display device may be used as a display device for reproducing a still image or a moving image, and when used as a display device for reproducing a moving image, the driving method may be either a simple matrix (passive matrix) method or an active matrix method.
  • Lighting sources include home lighting, interior lighting, backlights for watches and LCDs, signboard advertisements, traffic lights, light sources for optical storage media, light sources for electrophotographic copiers, light sources for optical communication processors, and light sources for optical sensors.
  • the present invention is not limited to these.
  • FIG. 3 is a schematic diagram illustrating an example of a display device including an organic EL element.
  • FIG. 3 is a schematic diagram of a display such as a mobile phone for displaying image information by light emission of an organic EL element.
  • the display 1 includes a display unit A having a plurality of pixels, a control unit B that performs image scanning of the display unit A based on image information, a wiring unit C that electrically connects the display unit A and the control unit B, and the like.
  • the control unit B is electrically connected to the display unit A via the wiring unit C, sends a scanning signal and an image data signal to each of the plurality of pixels based on image information from outside, and controls the pixels for each scanning line by the scanning signal. , Sequentially emit light according to the image data signal, perform image scanning, and display image information on the display unit A.
  • FIG. 4 is a schematic diagram of a display device using an active matrix system.
  • the display section A has a wiring section C including a plurality of scanning lines 5 and data lines 6 and a plurality of pixels 3 on a substrate.
  • the main members of the display unit A will be described below.
  • FIG. 4 shows a case where light emitted from the pixel 3 (emitted light L) is extracted in the direction of the white arrow (downward).
  • the scanning lines 5 and the plurality of data lines 6 of the wiring portion are each made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a grid and are connected to the pixels 3 at orthogonal positions (details are shown in the drawing). Not).
  • the pixel 3 receives an image data signal from the data line 6 and emits light in accordance with the received image data.
  • FIG. 5 is a schematic diagram showing a circuit of a pixel.
  • the pixel includes an organic EL element 10, a switching transistor 11, a driving transistor 12, a capacitor 13, and the like.
  • Full-color display can be performed by using red, green, and blue light-emitting organic EL elements as the organic EL elements 10 in a plurality of pixels and juxtaposing them on the same substrate.
  • an image data signal is applied from the control unit B to the drain of the switching transistor 11 via the data line 6.
  • a scanning signal is applied from the control unit B to the gate of the switching transistor 11 via the scanning line 5
  • the driving of the switching transistor 11 is turned on, and the image data signal applied to the drain is transferred to the capacitor 13 and the driving transistor 12. Transmitted to the gate.
  • the capacitor 13 is charged according to the potential of the image data signal, and the driving of the drive transistor 12 is turned on.
  • the driving transistor 12 has a drain connected to the power supply line 7, a source connected to the electrode of the organic EL element 10, and from the power supply line 7 to the organic EL element 10 according to the potential of the image data signal applied to the gate. Current is supplied.
  • the driving of the switching transistor 11 is turned off. However, even if the driving of the switching transistor 11 is turned off, the capacitor 13 holds the potential of the charged image data signal, so that the driving of the driving transistor 12 is kept on and the next scanning signal is applied. The light emission of the organic EL element 10 continues until this.
  • the driving transistor 12 is driven according to the potential of the next image data signal synchronized with the scanning signal, and the organic EL element 10 emits light.
  • the organic EL element 10 emits light by providing a switching transistor 11 and a driving transistor 12 as active elements to the organic EL elements 10 of each of the plurality of pixels, and emitting light of the organic EL elements 10 of each of the plurality of pixels 3 It is carried out.
  • a light emitting method is called an active matrix method.
  • the light emission of the organic EL element 10 may be a light emission of a plurality of gradations by a multi-valued image data signal having a plurality of gradation potentials, or a predetermined light emission amount on / off by a binary image data signal. Good. Further, the holding of the potential of the capacitor 13 may be continued until the next scanning signal is applied, or may be discharged immediately before the next scanning signal is applied.
  • the present invention is not limited to the active matrix method described above, but may be a passive matrix light emission drive in which the organic EL element emits light in accordance with a data signal only when a scanning signal is scanned.
  • FIG. 6 is a schematic diagram of a display device using a passive matrix system.
  • a plurality of scanning lines 5 and a plurality of image data lines 6 are provided in a lattice shape so as to face each other with the pixel 3 interposed therebetween.
  • the scanning signal of the scanning line 5 is applied by the sequential scanning, the pixels 3 connected to the applied scanning line 5 emit light according to the image data signal.
  • the passive matrix method there is no active element in the pixel 3, and the manufacturing cost can be reduced.
  • the organic EL device of the present invention By using the organic EL device of the present invention, a display device with improved luminous efficiency was obtained.
  • the organic EL element of the present invention can be used for a lighting device.
  • the organic EL device of the present invention may be used as an organic EL device having a resonator structure.
  • the intended use of the organic EL device having such a resonator structure is, for example, a light source of an optical storage medium, a light source of an electrophotographic copying machine, a light source of an optical communication processor, a light source of an optical sensor, and the like. Not limited. Further, it may be used for the above purpose by causing laser oscillation.
  • the organic EL element of the present invention may be used as a kind of lamp for illumination or an exposure light source, a projection device of a type for projecting an image, or a type of a type for directly recognizing a still image or a moving image. It may be used as a display device (display).
  • a driving method may be either a passive matrix method or an active matrix method.
  • a full-color display device can be manufactured by using two or more kinds of the organic EL elements of the present invention having different emission colors.
  • white light can be obtained by simultaneously emitting a plurality of light-emitting colors and mixing colors.
  • a plurality of emission colors those containing three emission maximum wavelengths of the three primary colors of red, green and blue, or two emission using the relationship of complementary colors such as blue and yellow, blue green and orange, etc. What contained the maximum wavelength may be used.
  • a mask is provided only when a light-emitting layer, a hole transport layer, an electron transport layer, or the like is formed, and the layers may be simply arranged such as by applying different masks. Since the other layers are common, patterning such as a mask is not necessary.
  • an electrode film can be formed on one surface by a vapor deposition method, a casting method, a spin coating method, an inkjet method, a printing method, or the like, and productivity is improved. According to this method, unlike a white organic EL device in which light-emitting elements of a plurality of colors are arranged in parallel in an array, the elements themselves emit white light.
  • the non-light-emitting surface of the organic EL device of the present invention is covered with a glass case, and a 300 ⁇ m-thick glass substrate is used as a sealing substrate, and an epoxy-based photocurable adhesive (Lux made by Toagosei Co., Ltd.) Track LC0629B) is applied on top of the cathode, brought into close contact with the transparent support substrate, irradiated with UV light from the glass substrate side, cured, sealed, and illuminated as shown in FIGS. A device can be formed.
  • FIG. 1 An epoxy-based photocurable adhesive
  • FIG. 7 is a schematic view of a lighting device, in which an organic EL element (organic EL element 101 in the lighting device) of the present invention is covered with a glass cover 102 (the sealing operation with the glass cover is a lighting operation).
  • the test was performed in a glove box under a nitrogen atmosphere (in an atmosphere of a high-purity nitrogen gas having a purity of 99.999% or more) without bringing the organic EL element 101 in the apparatus into contact with the air.
  • FIG. 8 is a cross-sectional view of the lighting device.
  • 105 denotes a cathode
  • 106 denotes an organic functional layer
  • 107 denotes a glass substrate with a transparent electrode.
  • the glass cover 102 is filled with a nitrogen gas 108 and a water catching agent 109 is provided.
  • Example 1 ⁇ Preparation of Organic EL Element 1-1> A 150 nm thick ITO (indium tin oxide) film was formed on a 50 mm ⁇ 50 mm glass substrate having a thickness of 0.7 mm as an anode. After patterning, the transparent substrate provided with the ITO transparent electrode was ultrasonically cleaned with isopropyl alcohol. Next, the substrate was dried with dry nitrogen gas and subjected to UV ozone cleaning for 5 minutes. Thereafter, the transparent substrate was fixed to a substrate holder of a commercially available vacuum evaporation apparatus. Each of the evaporation crucibles in the vacuum evaporation apparatus was filled with the constituent material of each layer in an amount optimal for producing each element.
  • ITO indium tin oxide
  • the crucible for vapor deposition used was made of a molybdenum or tungsten resistance heating material. After the pressure was reduced to a degree of vacuum of 1 ⁇ 10 ⁇ 4 Pa, the deposition crucible containing HAT-CN (1,4,5,8,9,12-hexaazatriphenylenehexacarbonitrile) was energized and heated. And it vapor-deposited on the ITO transparent electrode at the vapor deposition rate of 0.1 nm / sec, and formed the 1st hole injection layer with a layer thickness of 20 nm. Next, compound 4-A represented by the following structural formula was deposited on the first hole injection layer at a deposition rate of 0.1 nm / sec to form a first hole transport layer having a thickness of 50 nm.
  • HAT-CN 1,4,5,8,9,12-hexaazatriphenylenehexacarbonitrile
  • compound 4-B represented by the following structural formula was deposited on the first hole transport layer at a deposition rate of 0.1 nm / sec to form an electron blocking layer having a thickness of 10 nm.
  • Compound 4-C represented by the following structural formula as a host compound of the first light-emitting layer, and compound 4-D as a blue fluorescent light-emitting dopant were formed at a deposition rate of 0.1 nm / sec so as to be 95% and 5% by volume, respectively. Co-evaporation was performed to form a first light-emitting layer having a thickness of 30 nm.
  • compound 4-E represented by the above structural formula was deposited at a deposition rate of 0.1 nm / sec to form a first electron transporting layer having a thickness of 30 nm.
  • a first light emitting unit including the first hole injection layer, the first hole transport layer, the electron blocking layer, the first light emitting layer, and the first electron transport layer was manufactured.
  • the comparative compound 1 and Li were co-deposited at a deposition rate of 0.1 nm / sec so as to be 95% and 5% by volume, respectively, and a 20-nm-thick intermediate connector layer was formed on the first electron transport layer.
  • a generating layer was formed.
  • HAT-CN (1,4,5,8,9,12-hexaazatriphenylene hexacarbonitrile) was deposited at a deposition rate of 0.1 nm / sec on the intermediate connector layer (charge) in the same manner as the first hole transport layer. (A generation layer) to form a second hole injection layer having a thickness of 20 nm.
  • compound 4-A was deposited on the second hole injection layer at a deposition rate of 0.1 nm / sec to form a second hole transport layer having a thickness of 60 nm. 79%, 20%, and 79% of the compound 4-F represented by the above structural formula, Ir (ppy) 3 as a green phosphorescent dopant, and Ir (piq) 3 as a red phosphorescent dopant, respectively, as a host compound of the second light emitting layer. % By volume at a deposition rate of 0.1 nm / sec to form a second light emitting layer having a thickness of 20 nm.
  • compound 4-E was deposited at an evaporation rate of 0.1 nm / sec to form a second electron transport layer having a thickness of 30 nm.
  • a second light emitting unit including the second hole injection layer, the second hole transport layer, the second light emitting layer, and the second electron transport layer was manufactured. Further, after forming LiQ to a thickness of 2 nm on the second electron transporting layer, 100 nm of aluminum was evaporated to form a cathode.
  • the non-light-emitting surface side of the device was covered with a can-shaped glass case under an atmosphere of high-purity nitrogen gas having a purity of 99.999% or more, and wiring for taking out electrodes was provided, thereby producing an organic EL device 1-1.
  • Organic EL devices 1-2 to 1-40 were produced in the same manner as in the organic EL device 1-1, except that the compound of the charge generation layer as the intermediate connector layer was changed as shown in Table I below.
  • the charge generation layer contains 5% of Li, but the notation of Li is omitted in the table.
  • the change amount of the drive voltage obtained above is applied to the following equation, and the relative value of the change amount of the drive voltage of each organic EL element with respect to the change amount of the drive voltage of the organic EL element 1-1 is determined by the relative drive under high-temperature storage. It was obtained as a voltage change.
  • Relative drive voltage change (%) due to high temperature storage (drive voltage change of each organic EL element / drive voltage change of organic EL element 1-1) ⁇ 100 The smaller the obtained numerical value, the better the result.
  • each organic EL element obtained above can be measured, for example, by referring to Noboru Ota “Color Engineering 2nd Edition” (Tokyo Denki University Press). Specifically, the emission spectrum of each organic EL element when lighting was performed at room temperature (within a range of about 23 to 25 ° C.) under a constant current density of 50 mA / cm 2 was measured using a spectral radiance meter CS- 2000 (manufactured by Konica Minolta).
  • the spectrum obtained by this measurement is converted to chromaticity coordinates x, y using the tristimulus values X, Y, Z from the original stimuli [X], [Y], [Z] determined in the CIE1931 color system. Converted.
  • the emission luminance of each organic EL element when lighting was performed at room temperature under a constant current density condition of 50 mA / cm 2 was measured using a spectral radiance meter CS-2000 (manufactured by Konica Minolta). . Further, continuous driving was performed under the same conditions, and the time until the luminance was reduced by 30% was determined as the light emission life.
  • a chromaticity difference ⁇ E xy was calculated from the initial (LT 100 ) chromaticity coordinates x, y and the chromaticity coordinates x, y when the luminance was reduced by 30% (LT 70 ) by the following equation.
  • ⁇ E xy [(x LT100 ⁇ x LT70 ) 2 + (y LT100 ⁇ y LT70 ) 2 ] 1/2
  • Relative chromaticity difference (%) (chromaticity difference of each organic EL element / chromaticity difference of organic EL element 1-1) ⁇ 100
  • Example 2 ⁇ Preparation of organic EL elements 2-1 to 2-7> An organic EL device 2-1 was produced in the same manner as in the production of the organic EL device 1-1 in Example 1, except that Li used as a material of the intermediate connector layer (charge generation layer) was changed to Na. Further, organic EL devices 2-2 to 2-7 were manufactured in the same manner as in the preparation of organic EL device 2-1 except that comparative compound 1 was used as shown in Table II below. In the organic EL elements 2-1 to 2-7, the charge generation layer contains 5% of Na, but Na is not shown in the table. In Example 2, the same evaluation as in Example 1 was performed, and a relative evaluation was performed on the organic EL element 2-1 instead of the organic EL element 1-1.
  • Example 3 ⁇ Preparation of Organic EL Devices 3-1 to 3-7> An organic EL device 3-1 was produced in the same manner as in the production of the organic EL device 1-1 in Example 1, except that Li used as a material of the intermediate connector layer (charge generation layer) was changed to Ca. Organic EL devices 3-2 to 3-7 were prepared in the same manner as in the preparation of organic EL device 3-1 except that comparative compound 1 was changed as shown in Table III below. In the organic EL elements 3-1 to 3-7, the charge generation layer contains 5% of Ca, but Ca is not shown in the table. Also in Example 3, the same evaluation as in Example 1 was performed, and a relative evaluation was performed on the organic EL element 3-1 instead of the organic EL element 1-1.
  • Example 4 ⁇ Preparation of organic EL elements 4-1 to 4-32>
  • the organic EL device 4- 1-4 to 32-32 were produced. Also, in Example 4, the same evaluation as in Example 1 was performed, and a relative evaluation was performed on the organic EL element 4-1 instead of the organic EL element 1-1.
  • Example 5 ⁇ Production of organic EL elements 5-1 to 5-7> Except that the Li used as the material of the intermediate connector layer (charge generation layer) was changed to Sm and the comparative compound 1 was as shown in Table V below in the preparation of the organic EL device 1-1 in Example 1 above. Produced organic EL elements 5-1 to 5-7 in the same manner. In the organic EL elements 5-1 to 5-7, the charge generation layer contains 5% of Sm, but the notation of Sm is omitted in the table. Also in Example 5, the same evaluation as in Example 1 was performed, and a relative evaluation was performed on the organic EL element 5-1 instead of the organic EL element 1-1.
  • Example 6 ⁇ Production of organic EL elements 6-1 to 6-18> Except that Li used as the material of the intermediate connector layer (charge generation layer) was changed to Yb in the production of the organic EL device 1-1 in Example 1 and that Comparative Compound 1 was changed as shown in Table VI below Produced organic EL elements 6-1 to 6-18 in the same manner.
  • the charge generation layer contains 5% of Yb, but the notation of Yb is omitted in the table.
  • Example 6 the same evaluation as in Example 1 was performed, and a relative evaluation was performed on the organic EL element 6-1 instead of the organic EL element 1-1.
  • Example 7 ⁇ Preparation of organic EL elements 7-1 to 7-7> Except that Li used as a material for the intermediate connector layer (charge generation layer) was changed to Eu and that Comparative Compound 1 was as shown in Table VII below in the preparation of the organic EL device 1-1 in Example 1 above. Produced organic EL elements 7-1 to 7-7 in the same manner. In the organic EL elements 7-1 to 7-7, the charge generation layer contains 5% of Eu, but the notation of Eu is omitted in the table. Also in Example 7, the same evaluation as in Example 1 was performed, and the relative evaluation for the organic EL element 7-1 was performed instead of the organic EL element 1-1.
  • the organic EL device of the present invention has improved voltage rise during driving, durability after high-temperature storage, and color shift as compared with the organic EL device of the comparative example.
  • the present invention can be used for an organic electroluminescence device in which voltage rise during driving, durability and color shift are improved.
  • Reference Signs List 1 display 3 pixel 5 scanning line 6 data line 7 power supply line 10 organic EL element 11 switching transistor 12 drive transistor 13 capacitor 101 organic EL element 102 in lighting device glass cover 105 cathode 106 organic functional layer 107 glass substrate with transparent electrode 108 nitrogen Gas 109 Water collecting agent 110 Organic EL element 111 Anode 112 First light emitting unit 113 Intermediate connector layer 114 Second light emitting unit 115 Cathode 116 Support substrate 117 First hole injection layer 118 First hole transport layer 119 First light emitting layer 120 1 electron transport layer 121 second hole injection layer 122 second hole transport layer 123 second light emitting layer 124 second electron transport layer A display unit B control unit C wiring unit L emission light

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Abstract

La présente invention porte sur un élément électroluminescent organique comprenant une électrode positive, une électrode négative, des première et seconde couches électroluminescentes qui sont disposées entre les électrodes positive et négative, et une couche de connecteur intermédiaire disposée entre les première et seconde couches électroluminescentes. L'élément électroluminescent organique est caractérisé en ce que la couche de connecteur intermédiaire comprend un métal alcalin ou un métal alcalino-terreux, et la couche de connecteur intermédiaire ou une couche entre la couche de connecteur intermédiaire et la première couche électroluminescente comprend un composé ayant une structure représentée par la formule générale (1). [Dans la formule générale (1), A1 et A2 sont des résidus qui forment un hétérocycle aromatique à 6 chaînons avec des atomes d'azote, et l'hétérocycle aromatique à 6 chaînons peut être annelé. L est une liaison simple, un cycle hydrocarboné aromatique, un cycle hétérocyclique aromatique ou un groupe alkyle.]
PCT/JP2019/005633 2018-07-09 2019-02-15 Élément électroluminescent organique WO2020012686A1 (fr)

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