Organic metal complex, and organic light-emitting element, display device, imaging device, electronic equipment, lighting device and mobile object each containing same

Abstract

The present disclosure provides an organic metal complex characterized by being represented by general formula (1). In general formula (1), M represents a metal atom and is selected from Ir, Pt, Os, Rh, Pd and Ru; R1 to R8 independently represent a hydrogen atom and a substituent, in which at least one of R1 to R8 represents the substituent; and at least one of R9 and R10 represents the alkyl group having 2 or less carbon atoms.

Description

Organometallic complex, organic light-emitting element having the same, display device, imaging device, electronic device, lighting device, mobile object

[0001] The present invention relates to an organometallic complex, an organic light-emitting element having the same, a display device, an imaging device, an electronic device, a lighting device, and a mobile object.

[0002] An organic light-emitting element is an electronic element having a first electrode, a second electrode, and an organic compound layer disposed between these electrodes. By injecting electrons and holes from this pair of electrodes into the organic compound layer, excitons of a light-emitting organic compound in the organic compound layer are generated, and when the excitons return to the ground state, the organic light-emitting element emits light. Organic light-emitting elements are also called organic electroluminescence elements or organic EL elements.

[0003] Light-emitting organic compounds can be roughly divided into two types, fluorescent materials and phosphorescent materials, based on the principle of light emission. It is known that in the electrical generation of excitons in organic light-emitting devices, phosphorescent materials exhibit higher luminous efficiency than fluorescent materials due to quantum mechanical principles. Specifically, as a green phosphorescent material, Ir(ppy) ３ is known.

[0004]

[0005] New materials have been developed for organic light-emitting devices to improve driving voltage, luminescence quantum yield, color gamut, device life, etc. Patent Document 1 describes the following compound A as a compound for light-emitting devices that maintains high brightness for a long period of time and is little deteriorated by current flow. Patent Document 2 describes an organometallic complex having a ligand with the same structure as compound A as a phosphorescent compound. Patent Document 3 describes a material having an alkyl or cycloalkyl group having 3 to 10 carbon atoms at the 1-position of a dibenzofuran in the ligand in order to improve the life or efficiency of organic light-emitting devices, and specifically describes the following compounds B and C. Patent Document 4 describes compound D as a complex for improving efficiency, operating voltage, life, and color coordinates.

[0006]

[0007] Patent Document 1: JP 2002-332291 A, US Patent Application Publication No. 2018 / 0282356, International Publication No. 2019 / 221484, International Publication No. 2014 / 023377

[0008] In organic light-emitting devices, a phenomenon known as roll-off, in which luminous efficiency decreases at high current densities, is known. The organometallic complexes described in Patent Documents 1 to 4 have room for improvement in terms of the so-called roll-off, in which the luminous efficiency at a second current density higher than the first current density decreases relative to the luminous efficiency at a first current density.

[0009] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an organometallic complex in which the rate of decrease in luminous efficiency at a second current density higher than the first current density is reduced relative to the luminous efficiency at a first current density.

[0010] The present invention provides an organometallic complex represented by the following general formula (1):

[0011]

[0012] In the general formula (1), M is a metal atom selected from Ir, Pt, Os, Rh, Pd, and Ru. １ ~R ８ are each independently selected from a hydrogen atom or a substituent. The substituent is any one of a halogen atom, a cyano group, a nitro group, a trialkylsilyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aryl group having two or less rings. ９ ~R １０ are each independently selected from a hydrogen atom or an alkyl group having 2 or less carbon atoms. １ ~R ８ At least one of is the substituent, or R ９ and R １０ At least one of the above is an alkyl group having 2 or less carbon atoms.

[0013] According to the present invention, it is possible to provide an organometallic complex in which the rate of decrease in luminous efficiency at a second current density higher than the first current density is reduced relative to the luminous efficiency at a first current density.

[0014] FIG. 1 is a schematic cross-sectional view showing an example of a pixel of a display device according to one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of an example of a display device using an organic light-emitting element according to one embodiment of the present invention. FIG. 3 is a schematic diagram of an example of a display device using an organic light-emitting element according to one embodiment of the present invention. FIG. 4 is a schematic diagram showing an example of an imaging device according to one embodiment of the present invention. FIG. 5 is a schematic diagram showing an example of a portable device according to one embodiment of the present invention. FIG. 6 is a schematic diagram showing an example of a display device according to one embodiment of the present invention. FIG. 7 is a schematic diagram showing an example of a bendable display device. FIG. 8 is a schematic diagram showing an example of an illumination device according to one embodiment of the present invention. FIG. 9 is a schematic diagram showing an automobile, which is an example of a moving body according to one embodiment of the present invention. FIG. 10 is a schematic diagram showing an example of a wearable device according to one embodiment of the present invention. FIG. 11 is a schematic diagram showing an example of a wearable device according to one embodiment of the present invention, having an imaging device.

[0015] Hereinafter, embodiments of the present invention will be described. The present invention is not limited to the following description, and it will be readily understood by those skilled in the art that various changes can be made in form and detail without departing from the spirit and scope of the present invention. In other words, the present invention should not be interpreted as being limited by the following description.

[0016] [Organometallic Complex Represented by General Formula (1)] As a result of investigations, the present inventors have found an organometallic complex represented by the following general formula (1) that reduces the decrease in photon efficiency even at high current densities.

[0017]

[0018] In the general formula (1), M is a metal atom selected from Ir, Pt, Os, Rh, Pd, and Ru. １ ~R ８ are each independently selected from a hydrogen atom or a substituent, and this substituent is any one of a halogen atom, a cyano group, a nitro group, a trialkylsilyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aryl group having two or less rings.

[0019] R ９ ~R １０are each independently selected from a hydrogen atom or an alkyl group having 2 or less carbon atoms.

[0020] However, R １ ~R ８ At least one of is the substituent, or R ９ and R １０ At least one of the above is an alkyl group having 2 or less carbon atoms.

[0021] In this specification, M is a metal atom that forms a complex, and specific examples thereof include Ir, Pt, Os, Rh, Pd, Ru, and Re. Of these, Ir is preferred.

[0022] In this specification, R １ ~R ８ The halogen atom is any one of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these, a fluorine atom is preferred from the viewpoint of thermal stability.

[0023] In this specification, R １ ~R ８ The alkyl groups in the trialkylsilyl group may each independently be alkyl groups having a different number of carbon atoms. Preferably, they are alkyl groups having 1 to 8 carbon atoms, and may be linear or branched alkyl groups. More specific examples include, but are not limited to, a trimethylsilyl group, a tert-butyldimethylsilyl group, and a triisopropylsilyl group.

[0024] In this specification, R １ ~R ８ The alkyl group may be a straight chain alkyl group or a branched alkyl group, and may have 1 to 20 carbon atoms, or may have 1 to 8 carbon atoms.

[0025] In this specification, R １ ~R ８ and R １１ ~R １８The cycloalkyl group may have 3 to 20 carbon atoms, or 3 to 10 carbon atoms. Cyclohexane or cyclopentane is preferred. A carbon atom in the cycloalkyl group may be replaced with an oxygen atom, but it is not preferred that two adjacent carbon atoms are both replaced with oxygen atoms. Only one carbon atom may be replaced with an oxygen atom.

[0026] In this specification, examples of the aryl group having two or less rings include a phenyl group, a naphthyl group, a pyridyl group, a benzothienyl group, a benzofuryl group, a benzoxazolyl group, a quinolinyl group, an isoquinolinyl group, etc., and preferably a phenyl group.

[0027] In this specification, examples of the aryl group include a phenyl group, a naphthyl group, a biphenyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a pyridine group, a carbazolyl group, a dibenzofuryl group, and a dibenzothienyl group.

[0028] In this specification, the alkyl group or cycloalkyl group may further have a substituent, and examples of the substituent include a halogen atom, a cyano group, and a nitro group. The halogen atom that can substitute for the alkyl group is any of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these, a fluorine atom is preferred from the viewpoint of thermal stability. Furthermore, in the alkyl group or cycloalkyl group, one or two or more non-adjacent methylene groups can be substituted with an -O- group, an -S- group, a -C(=O)- group, a -C(=O)O- group, a -O(C=O)- group, a -CH=CH- group, or a -C≡C- group, and a hydrogen atom can be substituted with a fluorine atom.

[0029] In this specification, the aryl group may have an alkyl group as a substituent. In the alkyl group, one or two or more non-adjacent methylene groups can be substituted by an —O— group, an —S— group, a —C(═O)— group, a —C(═O)O— group, a —O(C═O)— group, a —CH═CH— group, or a —C≡C— group, and a hydrogen atom can be substituted by a fluorine atom.

[0030] In this specification, the aryl group includes those further having a substituent, and specifically includes a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 4-biphenyl group, a 2-fluorenyl group, a 9-phenanthryl group, a 2-anthryl group, a 1-pyrenyl group, a 1-imidazolyl group, a 2-furyl group, a 3-benzofuryl group, a 4-dibenzofuryl group, a 2-thienyl group, a 3-benzothienyl group, a 2-dibenzothienyl group, a 2-pyridyl group, a 2-pyrimidinyl group, a 1-indolyl group, a 2-indo Examples of the fluorenyl group include, but are not limited to, a phenyl group, a 9-carbazolyl group, a p-chlorophenyl group, an o-tolyl group, a 4-methoxyphenyl group, a 4'-(1-hexynyl)phenyl group, a 2-(1-(1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8-hexadecafluoro)octyloxycarbonyl)phenyl group, a 4'-cyanobiphenyl group, a 2-(9,9-dimethyl)fluorenyl group, and a 3-(9,9-dioctyl)fluorenyl group.

[0031] R ９ ~R １０ are each independently selected from a hydrogen atom and an alkyl group having 2 or less carbon atoms, specifically a hydrogen atom, a methyl group, or an ethyl group.

[0032] The organometallic complex according to the present invention is １ ~R ８ At least one of the groups is the substituent, or R ９ and R １０ At least one of the groups is an alkyl group having two or less carbon atoms. This allows the organometallic complex according to the present invention to have the effect of reducing the decrease in luminous efficiency at high current densities. In other words, it is an organometallic complex with excellent roll-off properties.

[0033] R １ ~R ８ When at least one of is a substituent, R ９ and R １０ may all be hydrogen atoms.

[0034] R １ ~R ４ may be in the form of a hydrogen atom or an alkyl group independently selected from the above groups. ３is preferably a tert-butyl group.

[0035] R ５ ~R ８ may be in the form of a hydrogen atom or an alkyl group independently selected from the above groups.

[0036] R in general formula (1) ３ In other words, the general formula (1) may be in the following range:

[0037] R １ , R ２ , R ４ ~R ８ are each independently selected from a hydrogen atom or a substituent. The substituent is any one of a halogen atom, a cyano group, a nitro group, a trialkylsilyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted phenyl group. ３ is selected from a hydrogen atom, a halogen atom, a cyano group, a nitro group, a trialkylsilyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aryl group. ９ ~R １０ are each independently selected from a hydrogen atom and an alkyl group having 2 or less carbon atoms. １ ~R ８ is not a hydrogen atom, or R ９ and R １０ At least one of the above is an alkyl group having 2 or less carbon atoms.

[0038] In addition, R in general formula (1) ９ and R １０ is an alkyl group having 2 or less carbon atoms, R １ ~R ８ In the above, the aryl group is not limited to two rings or less. ９ and R １０ When either of R is an alkyl group having 2 or less carbon atoms, ９is preferably an alkyl group having 2 or less carbon atoms. That is, it may be in the range of the following general formula (1).

[0039] R １ ~R ８ are each independently selected from a hydrogen atom or a substituent. The substituent is any one of a halogen atom, a cyano group, a nitro group, a trialkylsilyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aryl group. ９ ~R １０ are each independently selected from a hydrogen atom and an alkyl group having 2 or less carbon atoms. ９ and R １０ At least one of the above is an alkyl group having 2 or less carbon atoms.

[0040] Specific structural formulas of the organometallic complexes of the present invention are shown below. An iridium complex is used as an example, but the same applies when other metals are used. The number of ligands may vary depending on the coordination number of the metal.

[0041]

[0042]

[0043]

[0044] Among the exemplified compounds, the following exemplified compounds have high solvent solubility and can be preferably used in film formation by coating.

[0045]

[0046]

[0047]

[0048] [Organic Compound Layer of an Organic Light-Emitting Device According to an Embodiment of the Invention] Next, the organic compound layer of an organic light-emitting device according to an embodiment of the invention will be described. The organic light-emitting device according to this embodiment has at least a pair of electrodes, a first electrode and a second electrode, and an organic compound layer disposed between these electrodes. In the organic light-emitting device of this embodiment, the organic compound layer may be a single layer or a laminate consisting of multiple layers, as long as it has a light-emitting layer. The pair of electrodes may be an anode and a cathode.

[0049] When the organic compound layer is a laminate consisting of multiple layers, the organic compound layer may have a light-emitting layer. In addition to the light-emitting layer, the organic compound layer may have a hole injection layer, a hole transport layer, an electron blocking layer, a hole / exciton blocking layer, an electron transport layer, an electron injection layer, etc. The light-emitting layer may be a single layer or a laminate consisting of multiple layers. The hole transport layer and the electron transport layer are also called charge transport layers.

[0050] In the organic light-emitting device of this embodiment, the organometallic complex of this embodiment is contained in at least one of the organic compound layers. Specifically, the organometallic complex of this embodiment is contained in any of the hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole / exciton blocking layer, electron transport layer, electron injection layer, etc., and is preferably contained in the light-emitting layer. The transport layers between the first electrode and the light-emitting layer can be collectively referred to as a first charge transport layer. The transport layers between the second electrode and the light-emitting layer can be collectively referred to as a second charge transport layer. In other words, the light-emitting layer can be said to be in contact with both the first charge transport layer and the second charge transport layer.

[0051] In the organic light-emitting device of this embodiment, when the organometallic complex of this embodiment is contained in the light-emitting layer, the light-emitting layer may be a layer consisting solely of the organometallic complex of this embodiment, or may be a layer containing, in addition to the organometallic complex of this embodiment, a first organic compound and a second organic compound different from the first organic compound. The first organic compound may have a minimum excited triplet energy greater than the minimum excited triplet energy of the iridium complex of the present invention. The second organic compound may have a minimum excited triplet energy equal to or greater than the minimum excited triplet energy of the organometallic complex of the present invention and equal to or less than the minimum excited triplet energy of the first organic compound. Here, when the light-emitting layer is a layer containing the first organic compound and the second organic compound, the first organic compound may be a host for the light-emitting layer. Furthermore, the second organic compound may be an assist material. The organometallic complex of the present invention may be a guest or a dopant.

[0052] Here, the host is the compound with the largest weight ratio among the compounds constituting the light-emitting layer. The guest or dopant is a compound with a smaller weight ratio than the host among the compounds constituting the light-emitting layer, and is the compound that is primarily responsible for emitting light. The assist material is a compound with a smaller weight ratio than the host among the compounds constituting the light-emitting layer, and assists the guest in emitting light. The assist material is also called a second host.

[0053] When the organometallic complex according to this embodiment is used as a guest in the light-emitting layer, the concentration of the guest is preferably 0.01% by weight or more and 20% by weight or less, and more preferably 0.1% by weight or more and 10.0% by weight or less, based on the total weight of the light-emitting layer.

[0054] Furthermore, the lowest excited triplet energy of the first charge transport layer is preferably greater than the lowest excited triplet energy of the first organic compound. Furthermore, the lowest excited triplet energy of the second charge transport layer is preferably greater than the lowest excited triplet energy of the first organic compound. The lowest excited triplet energy of the charge transport layer can be estimated by the lowest excited triplet energy of the constituent materials of the layer. When the charge transport layer is composed of multiple materials, the lowest excited triplet energy may be the lowest excited triplet energy of the compound with the largest weight ratio.

[0055] The present inventors have conducted various studies and found that using the organometallic complex according to this embodiment as a guest in the light-emitting layer provides highly efficient, high-brightness light output and good roll-off characteristics. This light-emitting layer may be a single layer or multiple layers, and it is also possible to mix the light-emitting color of this embodiment with that of the other light-emitting layers by including a light-emitting material having another light-emitting color. "Multiple layers" refers to a state in which multiple light-emitting layers are stacked. In this case, the light-emitting color of the organic light-emitting element is not limited to the same hue as the light-emitting color of the single layer. More specifically, it may be white or an intermediate color. In the case of white, the white color may be obtained by emitting red, blue, and green light from each light-emitting layer, or by combining complementary light-emitting colors.

[0056] The organometallic complex according to this embodiment can also be used as a constituent material for organic compound layers other than the light-emitting layer that constitutes the organic light-emitting device of this embodiment, specifically, as a constituent material for an electron transport layer, an electron injection layer, a hole transport layer, a hole injection layer, a hole blocking layer, etc.

[0057] When manufacturing the organic light-emitting device according to this embodiment, conventionally known low-molecular-weight and high-molecular-weight hole-injecting or hole-transporting compounds, host compounds, light-emitting compounds, electron-injecting or electron-transporting compounds, etc. may be used together as needed. Examples of these compounds are listed below.

[0058] As the hole injection and transport material, a material with high hole mobility is preferred so that holes can be easily injected from the anode and the injected holes can be transported to the light-emitting layer. Furthermore, a material with a high glass transition temperature is preferred to reduce deterioration of film quality, such as crystallization, in organic light-emitting devices. Examples of low-molecular-weight and high-molecular-weight materials with hole injection and transport properties include triarylamine derivatives, arylcarbazole derivatives, phenylenediamine derivatives, triazole derivatives, oxadiazole derivatives, imidazole derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, polyarylamine derivatives, polyvinylcarbazole derivatives, polythiophene derivatives, conductive polymers such as PEDOT-PSS, and copolymers or mixtures thereof. Furthermore, the above-mentioned hole injection and transport materials are also suitable for use in electron blocking layers.

[0059] Specific examples of compounds that can be used as hole injecting and transporting materials are shown below, but the present invention is not limited to these.

[0060]

[0061]

[0062] In addition to the organometallic complex according to one embodiment of the present invention, other luminescent materials may also be added as luminescent materials mainly involved in the luminescence function. Examples of other luminescent materials include fused ring compounds (e.g., fluorene derivatives, naphthalene derivatives, pyrene derivatives, perylene derivatives, tetracene derivatives, anthracene derivatives, rubrene, etc.), quinacridone derivatives, coumarin derivatives, stilbene derivatives, organoaluminum complexes such as tris(8-quinolinolato)aluminum, iridium complexes such as tris(2-phenylpyridinato)iridium, platinum complexes, rhenium complexes, copper complexes, europium complexes, ruthenium complexes, and polymer derivatives such as poly(phenylenevinylene) derivatives, poly(fluorene) derivatives, and poly(phenylene) derivatives.

[0063] Specific examples of compounds that can be used as light-emitting materials are shown below, but the present invention is not limited to these.

[0064]

[0065]

[0066] Examples of the light-emitting layer host or light-emitting assist material contained in the light-emitting layer include aromatic hydrocarbon compounds or derivatives thereof, as well as polymers such as carbazole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, triazine derivatives, organoaluminum complexes such as tris(8-quinolinolato)aluminum, organic beryllium complexes, polyphenylene derivatives, polyphenylenevinylene derivatives, polyfluorene derivatives, and polyvinylcarbazole derivatives, as well as copolymers or mixtures thereof.

[0067] Specific examples of compounds that can be used as the light-emitting layer host or light-emitting assist material contained in the light-emitting layer are shown below, but the present invention is not limited to these.

[0068]

[0069]

[0070]

[0071] The electron transporting material can be arbitrarily selected from those capable of transporting electrons injected from the cathode to the light-emitting layer, and is selected in consideration of the balance with the hole mobility of the hole transporting material. Examples of materials having electron transport properties include oxadiazole derivatives, oxazole derivatives, pyrazine derivatives, triazole derivatives, triazine derivatives, quinoline derivatives, quinoxaline derivatives, phenanthroline derivatives, organoaluminum complexes, and fused ring compounds (e.g., fluorene derivatives, naphthalene derivatives, chrysene derivatives, anthracene derivatives, etc.). Furthermore, the above electron transporting materials are also suitable for use in hole-blocking layers.

[0072] Specific examples of compounds that can be used as electron transporting materials are shown below, but the present invention is not limited to these.

[0073]

[0074] The electron injection material can be arbitrarily selected from those that allow easy electron injection from the cathode, and is selected in consideration of the balance with hole injection properties, etc. Organic compounds include n-type dopants and reducing dopants. Examples include compounds containing alkali metals such as lithium fluoride, lithium complexes such as lithium quinolinol, benzimidazolidene derivatives, imidazolidene derivatives, fulvalene derivatives, and acridine derivatives.

[0075] [Configuration of Organic Light-Emitting Element] The organic light-emitting element is provided by forming a first electrode, an organic compound layer, and a second electrode on an insulating layer provided on a substrate. A protective layer, a color filter, etc. may be provided on the second electrode. When a color filter is provided, a planarizing layer may be provided between the second electrode and the protective layer. The planarizing layer may be made of acrylic resin or the like. Either the first electrode or the second electrode may be an anode, and the other may be a cathode.

[0076] [Substrate] Examples of the substrate include quartz, glass, silicon wafer, resin, and metal. Furthermore, the substrate may be provided with a switching element such as a transistor and wiring, and an insulating layer thereon. The insulating layer may be made of any material as long as it can form a contact hole to ensure electrical continuity between the anode and the wiring and can ensure insulation from unconnected wiring. For example, resins such as polyimide, silicon oxide, silicon nitride, etc. may be used.

[0077] [Electrodes] A pair of electrodes can be used. The pair of electrodes may be an anode and a cathode. When an electric field is applied in the direction in which the organic light-emitting element emits light, the electrode with a higher potential is the anode, and the other is the cathode. It can also be said that the electrode that supplies holes to the light-emitting layer is the anode, and the electrode that supplies electrons is the cathode.

[0078] The anode material should preferably have as large a work function as possible. Examples of such materials include simple metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, and tungsten, mixtures containing these metals, alloys of these metals, and metal oxides such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide. Conductive polymers such as polyaniline, polypyrrole, and polythiophene can also be used.

[0079] These electrode materials may be used alone or in combination of two or more. The anode may be composed of one layer or multiple layers.

[0080] When used as a reflective electrode, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, or an alloy or laminate thereof can be used. When used as a transparent electrode, a transparent conductive layer of an oxide such as indium tin oxide (ITO) or indium zinc oxide can be used, but is not limited to these. Photolithography can be used to form the electrode.

[0081] On the other hand, materials with a low work function are preferred for the cathode. Examples include alkali metals such as lithium, alkaline earth metals such as calcium, and metals such as aluminum, titanium, manganese, silver, lead, and chromium, as well as mixtures containing these metals. Alternatively, alloys combining these metals can be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, and zinc-silver can be used. Metal oxides such as indium tin oxide (ITO) can also be used. These electrode materials can be used alone or in combination of two or more. The cathode can have either a single-layer or multi-layer structure. Among these, silver is preferred, and a silver alloy is even more preferred to suppress silver aggregation. The alloy ratio is not critical as long as silver aggregation can be suppressed. For example, a 1:1 ratio is acceptable.

[0082] The cathode may be a top-emission element using an oxide conductive layer such as indium tin oxide (ITO), or a bottom-emission element using a reflective electrode such as aluminum (Al), and is not particularly limited. The method for forming the cathode is not particularly limited, but DC and AC sputtering methods are more preferable because they provide good film coverage and make it easier to reduce resistance.

[0083] [Protective Layer] A protective layer may be provided on the cathode. For example, by adhering glass provided with a moisture absorbent on the cathode, it is possible to reduce the intrusion of water and the like into the organic compound layer and reduce the occurrence of display defects. In another embodiment, a passivation film such as silicon nitride may be provided on the cathode to reduce the intrusion of water and the like into the organic compound layer. For example, after forming the cathode, the cathode may be transported to another chamber without breaking the vacuum, and a silicon nitride film having a thickness of 2 μm may be formed by a CVD method to serve as a protective layer. A protective layer may be provided using atomic layer deposition (ALD) after the film formation by the CVD method.

[0084] [Color Filter] A color filter may be provided on the protective layer. For example, a color filter taking into consideration the size of the organic light-emitting element may be provided on a separate substrate and then bonded to the substrate on which the organic light-emitting element is provided, or a color filter may be patterned on the protective layer described above using photolithography technology. The color filter may be made of a polymer.

[0085] [Planarization Layer] A planarization layer may be provided between the color filter and the protective layer. The planarization layer may be made of an organic compound, and may be either a low molecular weight or a high molecular weight compound, but is preferably a high molecular weight compound.

[0086] The planarizing layer may be provided above or below the color filter, and may be made of the same or different materials, such as polyvinyl carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0087] [Counter Substrate] An counter substrate may be provided on the planarization layer. The counter substrate is called a counter substrate because it is provided at a position corresponding to the aforementioned substrate. The constituent material of the counter substrate may be the same as that of the aforementioned substrate. When the aforementioned substrate is defined as a first substrate, the counter substrate may be a second substrate.

[0088] [Formation of Organic Compound Layers] The organic compound layers (hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, electron injection layer, etc.) constituting the organic light-emitting device according to one embodiment of the present invention are formed by the method described below.

[0089] The organic compound layer constituting the organic light-emitting device according to one embodiment of the present invention is not particularly limited, and a dry process or a wet process can be used. Examples of dry processes that can be used include vacuum deposition, ionization deposition, sputtering, plasma, and the like. Examples of wet processes that can be used include dissolving the compound in an appropriate solvent and using a known coating method (e.g., spin coating, casting, microgravure coating, gravure coating, bar coating, roll coating, wire bar coating, dip coating, spray coating, screen printing, flexographic printing, offset printing, inkjet printing, capillary coating, nozzle coating, and the like). Among these, vacuum deposition, ionization deposition, inkjet printing, nozzle coating, and the like are suitable for producing large-area organic light-emitting devices.

[0090] The thickness of each layer in the organic light-emitting device is preferably 1 nm to 10 μm. In particular, the thickness of the light-emitting layer of the organic compound layer is preferably 10 nm to 100 nm to obtain effective light-emitting characteristics.

[0091] When the light-emitting layer of the organic compound layer is formed by a wet process, the composition of these layers is dissolved in a solvent to form an ink. The viscosity of this ink can be adjusted depending on the type of printing method. When such an ink is applied to a printing method in which the solution passes through a discharge device, such as inkjet printing, the viscosity is preferably 1 to 20 mPa·s at 25°C to reduce clogging and deflection during discharge.

[0092] The ink can generally use a solvent having a boiling point of 70° C. to 300° C. under 1 atmosphere. The amount of the organic solvent is generally 10 to 100 parts by mass per part by mass of the material constituting each organic compound layer.

[0093] The drying method for the coating film obtained by the wet process can be appropriately selected depending on the type of each layer. Typically, the coating film can be heated in air or in an inert gas (nitrogen, argon, etc.) atmosphere at 100 to 250°C, preferably 110 to 200°C, for 5 to 60 minutes. Heating may also be performed under normal pressure (1 atmosphere) or reduced pressure (100 Pa to 0.1 MPa). The temperature, pressure, and time in this drying step can be adjusted to allow for the removal of the solvent in each layer.

[0094] When forming a film by a coating method, the film can be formed by combining with an appropriate binder resin.

[0095] Examples of the binder resin include, but are not limited to, polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0096] These binder resins may be used singly or in combination as homopolymers or copolymers, and may further contain known additives such as plasticizers, antioxidants, and ultraviolet absorbers, if necessary.

[0097] [Pixel Circuit] The light-emitting device may have a pixel circuit connected to the light-emitting element. The pixel circuit may be an active matrix type that controls the emission of the first light-emitting element and the second light-emitting element independently. The active matrix type circuit may be voltage-programmed or current-programmed. The drive circuit has a pixel circuit for each pixel. The pixel circuit may have a light-emitting element, a transistor that controls the emission brightness of the light-emitting element, a transistor that controls the emission timing, a capacitor that holds the gate voltage of the transistor that controls the emission brightness, and a transistor for connecting to GND without going through the light-emitting element.

[0098] The light-emitting device has a display region and a peripheral region arranged around the display region. The display region has pixel circuits, and the peripheral region has a display control circuit. The mobility of a transistor constituting the pixel circuit may be lower than the mobility of a transistor constituting the display control circuit.

[0099] The slope of the current-voltage characteristics of the transistors that make up the pixel circuit may be smaller than the slope of the current-voltage characteristics of the transistors that make up the display control circuit. The slope of the current-voltage characteristics can be measured by the so-called Vg-Ig characteristics.

[0100] The transistors that make up the pixel circuit are transistors connected to light-emitting elements such as the first light-emitting element.

[0101] [Pixels] The organic light emitting device has a plurality of pixels. Each pixel has sub-pixels that emit different colors. The sub-pixels may emit, for example, RGB colors.

[0102] The pixel emits light from an area called the pixel aperture. This area is the same as the first area. The pixel aperture may be 15 μm or less, or 5 μm or more. More specifically, it may be 11 μm, 9.5 μm, 7.4 μm, 6.4 μm, etc.

[0103] The distance between the subpixels may be 10 μm or less, and specifically may be 8 μm, 7.4 μm, or 6.4 μm.

[0104] The pixels may be arranged in a known manner in a plan view. For example, they may be in a stripe arrangement, a delta arrangement, a pentile arrangement, or a Bayer arrangement. The shape of the subpixels in a plan view may be any known shape. For example, they may be rectangular, quadrilaterals such as diamonds, or hexagons. Of course, a shape that is close to a rectangle, rather than an exact shape, is included in the rectangle. The shape of the subpixels and the pixel arrangement may be used in combination.

[0105] [Uses of the organic light-emitting device according to one embodiment of the present invention] The organic light-emitting device according to one embodiment of the present invention can be used as a component of a display device or a lighting device. Other uses include an exposure light source for an electrophotographic image forming device, a backlight for a liquid crystal display device, and a light-emitting device having a white light source and a color filter.

[0106] The display device may be an image information processing device that has an image input unit that inputs image information from an area CCD, a linear CCD, a memory card, etc., has an information processing unit that processes the input information, and displays the input image on the display unit.

[0107] The display unit of the imaging device or inkjet printer may have a touch panel function. The driving method of this touch panel function may be an infrared method, a capacitance method, a resistive film method, or an electromagnetic induction method, and is not particularly limited. The display device may also be used in the display unit of a multifunction printer.

[0108] Next, the display device according to this embodiment will be described with reference to the drawings.

[0109] 1A is a cross-sectional schematic diagram of an example of a pixel constituting a display device according to this embodiment. The pixel includes sub-pixels 10. The sub-pixels are divided into 10R, 10G, and 10B based on their light emission. The emitted colors may be distinguished by the wavelength of light emitted from the light-emitting layer, or the light emitted from the sub-pixels may be selectively transmitted or color-converted using a color filter or the like. Each sub-pixel includes a reflective electrode 2 serving as a first electrode on an interlayer insulating layer 1, an insulating layer 3 covering the edge of the reflective electrode 2, an organic compound layer 4 covering the first electrode and the insulating layer, a transparent electrode 5, a protective layer 6, and a color filter 7.

[0110] A transistor and a capacitor element may be disposed below or inside the interlayer insulating layer 1. The transistor and the first electrode may be electrically connected via a contact hole or the like (not shown).

[0111] The insulating layer 3 is also called a bank or a pixel separation film. It covers the edges of the first electrodes and surrounds the first electrodes. The portions where the insulating layer is not provided are in contact with the organic compound layer 4 and become light-emitting regions.

[0112] The organic compound layer 4 includes a hole injection layer 41, a hole transport layer 42, a first light-emitting layer 43, a second light-emitting layer 44, and an electron transport layer 45. The second electrode 5 may be a transparent electrode, a reflective electrode, or a semi-transparent electrode.

[0113] The protective layer 6 reduces the penetration of moisture into the organic compound layer. Although the protective layer is illustrated as a single layer, it may be a multi-layer structure. Each layer may include an inorganic compound layer and an organic compound layer.

[0114] The color filters 7 are divided into 7R, 7G, and 7B depending on their colors. The color filters may be formed on a planarization film (not shown). A resin protective layer (not shown) may be provided on the color filters. The color filters may be formed on a protective layer 6. Alternatively, the color filters may be provided on an opposing substrate such as a glass substrate and then bonded thereto.

[0115] 1B is a cross-sectional view showing an example of a display device having an organic light-emitting element and a transistor connected to the organic light-emitting element. The transistor is an example of an active element. The transistor may be a thin film transistor (TFT).

[0116] The display device 100 in Fig. 1B includes a substrate 11 made of glass, silicon, or the like, and an insulating layer 12 disposed thereon. An active element 18 such as a TFT is disposed on the insulating layer, along with a gate electrode 13, a gate insulating film 14, and a semiconductor layer 15 of the active element. The TFT 18 also includes the semiconductor layer 15, a drain electrode 16, and a source electrode 17. An insulating film 19 is disposed above the TFT 18. An anode 21 constituting the organic light-emitting element and the source electrode 17 are connected via a contact hole 20 provided in the insulating film.

[0117] The electrical connection between the electrodes (anode, cathode) included in the organic light-emitting element and the electrodes (source electrode, drain electrode) included in the TFT is not limited to the mode shown in Fig. 1B. In other words, it is sufficient that either the anode or the cathode is electrically connected to either the TFT source electrode or the drain electrode. TFT stands for thin film transistor.

[0118] 1B shows the organic compound layer as a single layer, the organic compound layer 22 may be a multi-layer structure. A first protective layer 24 and a second protective layer 25 are provided on the cathode 23 to reduce deterioration of the organic light-emitting element.

[0119] Although the display device 100 of FIG. 1B uses transistors as switching elements, other switching elements may be used instead.

[0120] The transistors used in the display device 100 of Figure 2(b) are not limited to transistors using single-crystal silicon wafers, but may also be thin-film transistors having an active layer on an insulating surface of a substrate. Examples of active layers include single-crystal silicon, amorphous silicon, microcrystalline silicon, and other non-single-crystal silicon, and non-single-crystal oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide. Thin-film transistors are also called TFT elements.

[0121] The transistors included in the display device 100 of Figure 1B may be formed within a substrate such as a Si substrate. Here, "formed within a substrate" means that the transistors are fabricated by processing the substrate itself, such as a Si substrate. In other words, having a transistor within a substrate can be seen as the substrate and the transistor being integrally formed.

[0122] The organic light-emitting element according to this embodiment has its emission brightness controlled by a TFT, which is an example of a switching element. By providing multiple organic light-emitting elements on a surface, an image can be displayed based on the emission brightness of each element. The switching element according to this embodiment is not limited to a TFT, but may also be a transistor formed from low-temperature polysilicon or an active matrix driver formed on a substrate such as a Si substrate. "On the substrate" can also be referred to as "inside the substrate." Whether to provide a transistor within the substrate or to use a TFT is determined by the size of the display unit. For example, for a display unit of about 0.5 inches, it is preferable to provide the organic light-emitting element on a Si substrate.

[0123] 2 is a schematic diagram showing an example of a display device according to this embodiment. The display device 1000 may have a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 between an upper cover 1001 and a lower cover 1009. The touch panel 1003 and the display panel 1005 are connected by flexible printed circuits FPCs 1002 and 1004. Transistors are printed on the circuit board 1007. The battery 1008 may not be provided if the display device is not a portable device, and may be provided in a different position even if the display device is a portable device.

[0124] The display device according to this embodiment may have color filters having red, green, and blue colors, and the red, green, and blue colors may be arranged in a delta array, a stripe array, or a mosaic array.

[0125] The display device according to the present embodiment may be used as a display unit of a mobile terminal. In this case, the display device may have both a display function and an operation function. Examples of the mobile terminal include a mobile phone such as a smartphone, a tablet, and a head-mounted display.

[0126] The display device according to this embodiment may be used in a display unit of an imaging device having an optical unit with multiple lenses and an imaging element that receives light that has passed through the optical unit. The imaging device may have a display unit that displays information acquired by the imaging element. The display unit may be a display unit exposed to the outside of the imaging device or a display unit located within the viewfinder. The imaging device may be a digital camera or a digital video camera. The imaging device may also be called a photoelectric conversion device.

[0127] 3A is a schematic diagram illustrating an example of an imaging device according to this embodiment. The imaging device 1100 may include a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The viewfinder 1101 may include a display device according to this embodiment. In this case, the display device may display not only an image to be captured, but also environmental information, imaging instructions, and the like. The environmental information may include the intensity of external light, the direction of external light, the speed at which the subject is moving, the possibility that the subject will be blocked by an obstruction, and the like.

[0128] Since the optimum timing for capturing an image is very short, it is better to display information as soon as possible. Therefore, it is preferable to use a display device using the organic light-emitting element of the present invention. This is because the organic light-emitting element has a fast response speed. A display device using an organic light-emitting element can be used more preferably than a liquid crystal display device, which requires a high display speed.

[0129] The imaging device 1100 has an optical section (not shown). The optical section has multiple lenses, which form an image on an imaging element housed in a housing 1104. The focus of the multiple lenses can be adjusted by adjusting their relative positions. This operation can also be performed automatically.

[0130] FIG. 3B is a schematic diagram illustrating an example of an electronic device according to this embodiment. The electronic device 1200 has a display unit 1201, an operation unit 1202, and a housing 1203. The housing 1203 may have a circuit, a printed circuit board having the circuit, a battery, and a communication unit. The operation unit 1202 may be a button or a touch panel type reaction unit. The operation unit may be a biometric recognition unit that recognizes a fingerprint to perform operations such as unlocking. An electronic device having a communication unit can also be called a communication device. The electronic device may further have a camera function by including a lens and an image sensor. An image captured by the camera function is displayed on the display unit. Examples of the electronic device include a smartphone and a laptop computer.

[0131] 4A and 4B are schematic diagrams showing an example of a display device according to this embodiment. Fig. 4A shows a display device such as a television monitor or a PC monitor. The display device 1300 has a frame 1301 and a display unit 1302. The light-emitting device according to this embodiment may be used in the display unit 1302.

[0132] The display device has a frame 1301 and a base 1303 that supports a display unit 1302. The base 1303 is not limited to the form shown in Fig. 4A. The lower side of the frame 1301 may also serve as the base.

[0133] The frame 1301 and the display unit 1302 may be curved. The radius of curvature may be 5000 mm or more and 6000 mm or less.

[0134] FIG. 4B is a schematic diagram illustrating another example of a display device according to the present embodiment. The display device 1310 in FIG. 4B is configured to be bendable, and is a so-called foldable display device. The display device 1310 has a first display unit 1311, a second display unit 1312, a housing 1313, and a bending point 1314. The first display unit 1311 and the second display unit 1312 may include a light-emitting device according to the present embodiment. The first display unit 1311 and the second display unit 1312 may be a single, seamless display unit. The first display unit 1311 and the second display unit 1312 can be separated by the bending point. The first display unit 1311 and the second display unit 1312 may each display different images, or the first and second display units may display a single image.

[0135] 5A is a schematic diagram illustrating an example of an illumination device according to this embodiment. The illumination device 1400 may include a housing 1401, a light source 1402, a circuit board 1403, an optical film 1404, and a light diffusion unit 1405. The light source may include an organic light-emitting element according to this embodiment. The optical filter may be a filter that improves the color rendering of the light source. The light diffusion unit can effectively diffuse light from the light source, such as for illumination, and deliver the light over a wide area. The optical filter and the light diffusion unit may be provided on the light emission side of the illumination device. If necessary, a cover may be provided on the outermost surface.

[0136] The lighting device is, for example, a device for illuminating a room. The lighting device may emit white, daylight white, or any other color from blue to red. It may have a dimming circuit for dimming them. The lighting device may have the organic light-emitting element of the present invention and a power supply circuit connected thereto. The power supply circuit is a circuit for converting AC voltage to DC voltage. Furthermore, white has a color temperature of 4200K, and daylight white has a color temperature of 5000K. The lighting device may have a color filter.

[0137] The lighting device according to this embodiment may also include a heat dissipation unit, which dissipates heat from within the device to the outside, and may be made of a material such as a metal with a high specific heat capacity or liquid silicon.

[0138] 5B is a schematic diagram of an automobile, which is an example of a moving body according to this embodiment. The automobile has tail lamps, which are an example of a lighting device. The automobile 1500 has tail lamps 1501, and may be configured to turn on the tail lamps when braking or the like is performed.

[0139] The tail lamp 1501 may include the organic light-emitting element according to this embodiment. The tail lamp may include a protective member for protecting the organic light-emitting element. The protective member may be made of any material as long as it has a certain degree of strength and is transparent, but it is preferably made of polycarbonate or the like. Polycarbonate may be mixed with a furandicarboxylic acid derivative, an acrylonitrile derivative, or the like.

[0140] The automobile 1500 may have a body 1503 and a window 1502 attached thereto. The window may be a transparent display as long as it is not a window for checking the front and rear of the automobile. The transparent display may have an organic light-emitting element according to this embodiment. In this case, constituent materials of the electrodes and the like of the organic light-emitting element are made of transparent materials.

[0141] The moving body according to this embodiment may be a ship, an aircraft, a drone, or the like. The moving body may have a body and a lighting device provided on the body. The lighting device may emit light to indicate the position of the body. The lighting device has the organic light-emitting element according to this embodiment.

[0142] 6A and 6B , application examples of the display devices according to the above-described embodiments will be described. The display device can be applied to systems that can be worn as wearable devices, such as smart glasses, HMDs, and smart contact lenses. The image capturing and display device used in such application examples includes an image capturing device capable of photoelectrically converting visible light and a display device capable of emitting visible light.

[0143] 6A illustrates glasses 1600 (smart glasses) according to one application example. An imaging device 1602 such as a CMOS sensor or a SPAD is provided on the front side of a lens 1601 of the glasses 1600. Furthermore, a display device according to any of the above-described embodiments is provided on the back side of the lens 1601.

[0144] The glasses 1600 further include a control device 1603. The control device 1603 functions as a power source that supplies power to the image capture device 1602 and the display device according to each embodiment. The control device 1603 also controls the operations of the image capture device 1602 and the display device. The lens 1601 is formed with an optical system for focusing light onto the image capture device 1602.

[0145] FIG. 6B illustrates glasses 1610 (smart glasses) according to one application example. The glasses 1610 include a control device 1612, which is equipped with an imaging device corresponding to the imaging device 1602 and a display device. A lens 1611 includes an optical system for projecting light emitted from the imaging device and the display device within the control device 1612, and an image is projected onto the lens 1611. The control device 1612 functions as a power source for supplying power to the imaging device and the display device, and controls the operation of the imaging device and the display device. The control device may include a gaze detection unit that detects the wearer's gaze. Infrared light may be used for gaze detection. The infrared light emitter emits infrared light toward the eyeball of a user gazing at a displayed image. An imaging unit with a light-receiving element detects the reflected light of the emitted infrared light from the eyeball, thereby obtaining an image of the eyeball. A reduction unit that reduces light from the infrared light emitter to the display unit in a planar view reduces degradation of image quality.

[0146] The gaze of the user relative to the displayed image is detected from an image of the eyeball obtained by capturing infrared light. Any known method can be used for gaze detection using an image of the eyeball. One example is a gaze detection method based on the Purkinje image formed by reflection of irradiated light on the cornea.

[0147] More specifically, gaze detection processing is performed based on the pupil-corneal reflex method, which calculates a gaze vector representing the orientation (rotation angle) of the eyeball based on the pupil image and Purkinje image included in the captured image of the eyeball, thereby detecting the user's gaze.

[0148] A display device according to an embodiment of the present invention may have an imaging device having a light receiving element, and may control the image displayed on the display device based on information about the user's line of sight from the imaging device.

[0149] Specifically, the display device determines a first field of view area where the user gazes and a second field of view area other than the first field of view area based on the line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the display device, or may be determined by an external control device and received. In the display area of ​​the display device, the display resolution of the first field of view area may be controlled to be higher than the display resolution of the second field of view area. In other words, the resolution of the second field of view area may be lower than that of the first field of view area.

[0150] The display area includes a first display area and a second display area different from the first display area, and a high-priority area is determined from the first display area and the second display area based on line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the display device, or may be determined by an external control device and received. The resolution of the high-priority area may be controlled to be higher than the resolution of areas other than the high-priority area. In other words, the resolution of an area with a relatively low priority may be lowered.

[0151] Note that AI may be used to determine the first field of view area and the area with high priority. The AI ​​may be a model configured to estimate the angle of gaze and the distance to an object in the line of sight from the image of the eyeball, using as training data an image of the eyeball and the direction in which the eyeball in the image was actually looking. The AI ​​program may be included in the display device, the imaging device, or an external device. If included in the external device, it is transmitted to the display device via communication.

[0152] When display control is performed based on visual recognition detection, the smart glasses can be preferably applied to smart glasses that further include an imaging device for capturing images of the outside world. The smart glasses can display captured external information in real time.

[0153] As described above, by using a device using the organic light-emitting element according to this embodiment, it is possible to provide a stable display with good image quality even over a long period of time.

[0154] As described above, by using a device using the organic light-emitting element according to this embodiment, it is possible to achieve both good visibility outdoors due to highly efficient and bright light output and power-saving display.

[0155] Examples will be described below, but the present invention is not limited to these examples.

[0156] Synthesis Example 1 Synthesis of Compound (4)

[0157]

[0158] Compound (4) was synthesized using the following procedure. First, the synthesis of the ligand will be described. In a nitrogen atmosphere, 2.12 g (10.5 mmol) of dibenzofuran-4-boronic acid, 1.70 g (10.0 mmol) of 4-(tert-butyl)-2-chloropyridine, 0.12 g (0.1 mmol) of tetrakistriphenylphosphine palladium, 30 ml of toluene, 15 ml of ethanol, and 15 ml of a 2 M aqueous solution of sodium carbonate were added to a 100 ml recovery flask, and the mixture was then heated from room temperature to 90°C and stirred for 4 hours. Toluene and water were added to extract the organic layer, and magnesium sulfate was added to the resulting organic layer, followed by filtration. The filtrate was concentrated and purified by silica gel column chromatography (mobile phase: chloroform). The solvent was distilled off, and the mixture was crystallized from an aqueous isopropyl alcohol (IPA) solution to obtain 3.00 g of the ligand. The structure is １ Identification was carried out by HMS.

[0159] Next, the synthesis of compound (4) will be described.

[0160]

[0161] Under a nitrogen atmosphere, 70.5 mg (0.2 mmol) of iridium chloride trihydrate, 3.00 g (9.95 mmol) of ligand, and 20 ml of ethylene glycol were added to a 100 ml recovery flask, and then the flask was irradiated with microwaves (150 W) for 1 hour. Water was added to the reaction mixture, which was then suction filtered and repeatedly dispersed and washed with methanol to obtain 220 mg of compound (4) as a yellow solid. HPLC analysis showed a purity of 99.5%. The structure was also determined by MS. １ Identification by H NMR. MS analysis: 1093.377 １ H NMR analysis (500 MHz, CDCl ３ ): 9.03 (1H, d, J / Hz = 1.5), 7.80 (1H, d, J / Hz = 8.0), 7.57 (1H, d, J / Hz = 8.0), 7.52 (1H, d, J / Hz = 6.0), 7.39 (1H, d, J / Hz = 8.0), 7 .35 (1H, dt, J / Hz=8.0, 1.0), 7.26 (1H, dt, J / Hz=8.0, 1.0), 6.96 (1H, dd, J / Hz=6.0, 2.0), 6.90 (1H, d, J / Hz=8.0), 1.41 (9H, s)

[0162] Synthesis Example 2: Synthesis of compound (13)

[0163]

[0164] Compound (13) was synthesized in the same manner as in Synthesis Example 1, except that 4-phenyl-2-chloropyridine was used instead of 4-(tert-butyl)-2-chloropyridine. HPLC analysis showed a purity of 99.4%. The structure was identified by MS. MS analysis: 1153.280

[0165] Synthesis Example 3 Synthesis of Compound (56)

[0166]

[0167] Compound (56) was synthesized in the same manner as in Synthesis Example 1, except that 1-methyldibenzofuran-4-boronic acid was used instead of dibenzofuran-4-boronic acid. HPLC analysis showed a purity of 99.2%. The structure was identified by MS. MS analysis: 1135.424

[0168] Synthesis Example 4 Synthesis of Compound (58)

[0169]

[0170] Compound (58) was synthesized in the same manner as in Synthesis Example 1, except that 4-cyclohexyl-2-chloropyridine was used instead of 4-(tert-butyl)-2-chloropyridine. HPLC analysis showed a purity of 99.5%. The structure was identified by MS. MS analysis: 1213.475

[0171] Synthesis Example 5 Synthesis of Compound (70)

[0172]

[0173] Compound (70) was synthesized in the same manner as in Synthesis Example 1, except that 1-ethyldibenzofuran-4-boronic acid was used instead of dibenzofuran-4-boronic acid. HPLC analysis showed a purity of 99.2%. The structure was identified by MS. MS analysis: 1177.474

[0174] [Example 1] The compound (4) obtained in Synthesis Example 1 was heated at 360°C, 3 x 10 －３ The resulting solution was purified by sublimation at 1000 KPa. The HPLC purity of the sublimate was 99.9%. Using the sublimate, an organic light-emitting device having an anode / hole injection layer / hole transport layer / electron blocking layer / light-emitting layer / hole blocking layer / electron transport layer / cathode structure was fabricated on a substrate in the following manner.

[0175] A glass substrate was used as a transparent conductive support substrate (ITO substrate) on which an ITO film was formed as an anode by sputtering to a thickness of 100 nm. The organic compound layer and electrode layer shown below were then formed on the ITO substrate in a thickness of 1×10. －５ Films were continuously formed by vacuum deposition using resistance heating in a vacuum chamber at 100 Pa. The opposing electrodes had an area of ​​3 mm ２ The layers were fabricated as follows: Hole injection layer (10 nm): HT16; Hole transport layer (40 nm): HT1; Light-emitting layer (30 nm): Host material: EM32, Guest material: Compound (4) (4 wt %); Electron transport layer (30 nm): ET20; Metal electrode layer 1 (15 nm): LiF; Metal electrode layer 2 (100 nm): Al

[0176] Next, in order to prevent deterioration of the organic light emitting element due to absorption of moisture, the device was covered with a protective glass plate in a dry air atmosphere and sealed with an acrylic resin adhesive.

[0177] The current efficiency of the obtained organic light-emitting device was measured using an ITO electrode as the anode and an Al electrode as the cathode. ２ The current efficiency was 94.8 cd / A at a current density of 50 mA / cm ２ The current efficiency was 79.2 cd / A.

[0178] [Example 2] Compound (13) obtained in Synthesis Example 2 was purified by sublimation in the same manner as compound (4) in Example 1 to obtain a sublimate with an HPLC purity of 99.8%. An organic light-emitting device was obtained in the same manner as in Example 1, except that the sublimate of Example 2 was used instead of the sublimate of Example 1.

[0179] The current efficiency of the obtained organic light-emitting device was measured using an ITO electrode as the anode and an Al electrode as the cathode. ２ The current efficiency was 95.0 cd / A at a current density of 50 mA / cm ２ The current efficiency was 80.5 cd / A.

[0180] [Example 3] Compound (56) obtained in Synthesis Example 3 was purified by sublimation in the same manner as compound (4) in Example 1 to obtain a sublimate with an HPLC purity of 99.9%. An organic light-emitting device was obtained in the same manner as in Example 1, except that the sublimate of Example 3 was used instead of the sublimate of Example 1.

[0181] The current efficiency of the obtained organic light-emitting device was measured using an ITO electrode as the anode and an Al electrode as the cathode. ２ The current efficiency at a current density of 50 mA / cm was 91.1 cd / A. ２ The current efficiency was 77.9 cd / A.

[0182] [Example 4] Compound (58) obtained in Synthesis Example 4 was purified by sublimation in the same manner as compound (4) in Example 1 to obtain a sublimate with an HPLC purity of 99.9%. An organic light-emitting device was obtained in the same manner as in Example 1, except that the sublimate of Example 4 was used instead of the sublimate of Example 1.

[0183] The current efficiency of the obtained organic light-emitting device was measured using an ITO electrode as the anode and an Al electrode as the cathode. ２ The current efficiency was 92.5 cd / A at a current density of 50 mA / cm ２ The current efficiency was 75.5 cd / A.

[0184] [Example 5] Compound (70) obtained in Synthesis Example 5 was purified by sublimation in the same manner as compound (4) in Example 1 to obtain a sublimate with an HPLC purity of 99.9%. An organic light-emitting device was obtained in the same manner as in Example 1, except that the sublimate of Example 5 was used instead of the sublimate of Example 1.

[0185] The current efficiency of the obtained organic light-emitting device was measured using an ITO electrode as the anode and an Al electrode as the cathode.２ The current efficiency at a current density of 50 mA / cm was 93.0 cd / A. ２ The current efficiency was 78.1 cd / A.

[0186] Reference Example 1 Ir(ppy) was purified by sublimation in the same manner as in compound (4) of Example 1 to obtain a sublimate with an HPLC purity of 99.9%. An organic light-emitting device was obtained in the same manner as in Example 1, except that the sublimate of Reference Example 1 was used instead of the sublimate of Example 1.

[0187] The current efficiency of the obtained organic light-emitting device was measured using an ITO electrode as the anode and an Al electrode as the cathode. ２ The current efficiency at a current density of 50 mA / cm was 75.0 cd / A. ２ The current efficiency was 62.3 cd / A.

[0188] Comparative Example 1 Comparative compound (1) was purified by sublimation in the same manner as compound (4) in Example 1 to obtain a sublimate with an HPLC purity of 99.9%. An organic light-emitting device was obtained in the same manner as in Example 1, except that the sublimate of Comparative Example 1 was used instead of the sublimate of Example 1.

[0189] The current efficiency of the obtained organic light-emitting device was measured using an ITO electrode as the anode and an Al electrode as the cathode. ２ The current efficiency at a current density of 50 mA / cm was 85.1 cd / A. ２ The current efficiency was 65.8 cd / A.

[0190] Comparative Example 2 Comparative compound (2) was purified by sublimation in the same manner as compound (4) in Example 1 to obtain a sublimate with an HPLC purity of 99.9%. An organic light-emitting device was obtained in the same manner as in Example 1, except that the sublimate of Comparative Example 3 was used instead of the sublimate of Example 1.

[0191] The current efficiency of the obtained organic light-emitting device was measured using an ITO electrode as the anode and an Al electrode as the cathode. ２ The current efficiency at a current density of 50 mA / cm was 86.9 cd / A. ２ The current efficiency was 65.0 cd / A.

[0192] Comparative Example 3 Comparative compound (3) was purified by sublimation in the same manner as compound (4) in Example 1 to obtain a sublimate with an HPLC purity of 99.9%. An organic light-emitting device was obtained in the same manner as in Example 1, except that the sublimate of Comparative Example 4 was used instead of the sublimate of Example 1.

[0193] The current efficiency of the obtained organic light-emitting device was measured using an ITO electrode as the anode and an Al electrode as the cathode. ２ The current efficiency at a current density of 50 mA / cm was 79.3 cd / A. ２ The current efficiency was 62.0 cd / A.

[0194] Comparative Example 4 Comparative compound (4) was purified by sublimation in the same manner as compound (4) in Example 1 to obtain a sublimate with an HPLC purity of 99.8%. An organic light-emitting device was obtained in the same manner as in Example 1, except that the sublimate of Comparative Example 4 was used instead of the sublimate of Example 1.

[0195] The current efficiency of the obtained organic light-emitting device was measured using an ITO electrode as the anode and an Al electrode as the cathode. ２ The current efficiency was 84.8 cd / A at a current density of 50 mA / cm ２ The current efficiency was 66.5 cd / A.

[0196] Comparative Example 5 Comparative compound (5) was purified by sublimation in the same manner as compound (4) in Example 1 to obtain a sublimate with an HPLC purity of 99.6%. An organic light-emitting device was obtained in the same manner as in Example 1, except that the sublimate of Comparative Example 5 was used instead of the sublimate of Example 1.

[0197] The current efficiency of the obtained organic light-emitting device was measured using an ITO electrode as the anode and an Al electrode as the cathode. ２ The current efficiency at a current density of 50 mA / cm was 86.1 cd / A. ２ The current efficiency was 67.7 cd / A.

[0198] Comparative Example 6 Comparative compound (6) was purified by sublimation in the same manner as compound (4) in Example 1 to obtain a sublimate with an HPLC purity of 99.6%. An organic light-emitting device was obtained in the same manner as in Example 1, except that the sublimate of Comparative Example 6 was used instead of the sublimate of Example 1.

[0199] The current efficiency of the obtained organic light-emitting device was measured using an ITO electrode as the anode and an Al electrode as the cathode. ２ The current efficiency was 85.5 cd / A at a current density of 50 mA / cm ２ The current efficiency was 64.0 cd / A.

[0200] The structural formulas of the comparative compounds are shown below.

[0201]

[0202]

[0203] Example 6 Using the compound (4) described in Example 1, an organic light-emitting device having an anode / hole injection layer / light-emitting layer / electron transport layer / cathode structure in this order on a substrate was fabricated as follows.

[0204] A glass substrate was used as a transparent conductive support substrate (ITO substrate) on which an ITO film was formed as an anode by sputtering to a thickness of 100 nm. This ITO substrate was washed with pure water and then with IPA, and subjected to UV-ozone treatment. A hole injection layer was then formed by spin coating. The film formation conditions were as follows: Coating liquid: Poly(3,4-ethylenedioxythiophene) polystyrene sulfonic acid aqueous solution (PEDOT; PSS aqueous solution, manufactured by Aldrich, conductivity 1×10 －５ S / cm, compound concentration 2.8% by mass) Spin coating conditions: 3000 rpm, 60 seconds, in a nitrogen atmosphere Annealing conditions: 200°C, 1 hour, in a nitrogen atmosphere Film thickness: 40 nm

[0205] Next, a light-emitting layer was formed by spin coating. The composition of the coating solution for forming the light-emitting layer and the film-forming conditions are as follows: Coating solution: Compound (4) 6.0% by mass, EM37 94.0% by mass, chlorobenzene 9900% by mass Spin coating conditions: 3000 rpm, 60 seconds, in a nitrogen atmosphere Annealing conditions: 110°C, 10 minutes, in a nitrogen atmosphere Film thickness: 30 nm

[0206] Finally, 1 x 10 －５ In a vacuum chamber at 100 Pa, an electron transport layer and an electrode layer were formed by a vacuum deposition method using resistance heating. ２ The film formation conditions were as follows: Electric transport layer: (50 nm) TPBi Metal electrode layer 1: (0.5 nm) LiF Metal electrode layer 2: (90 nm) Al

[0207] Thereafter, in order to prevent deterioration of the organic light emitting element due to absorption of moisture, the device was covered with a protective glass plate in a nitrogen atmosphere and sealed with an acrylic resin adhesive.

[0208] The current efficiency of the obtained organic light-emitting device was measured using an ITO electrode as the anode and an Al electrode as the cathode. ２ The current efficiency at a current density of 50 mA / cm was 55.9 cd / A. ２ The current efficiency was 45.4 cd / A.

[0209] Example 7 An organic light-emitting device was obtained in the same manner as in Example 6, except that compound (97) having an HPLC purity of 99.8% was used instead of compound (4).

[0210] The current efficiency of the obtained organic light-emitting device was measured using an ITO electrode as the anode and an Al electrode as the cathode. ２ The current efficiency at a current density of 50 mA / cm was 53.5 cd / A. ２ The current efficiency was 44.2 cd / A.

[0211] Reference Example 2 An organic light-emitting device was obtained in the same manner as in Example 6, except that Ir(ppy) 3 used in Reference Example 1 was used instead of the compound (4) in Example 6.

[0212] The current efficiency of the obtained organic light-emitting device was measured using an ITO electrode as the anode and an Al electrode as the cathode. ２ The current efficiency at a current density of 50 mA / cm was 35.2 cd / A. ２ The current efficiency was 29.1 cd / A.

[0213] Comparative Example 7 An organic light-emitting device was obtained in the same manner as in Example 6, except that the comparative compound (1) used in Comparative Example 1 was used instead of the compound (4) used in Example 6.

[0214] Comparative Example 8 An organic light-emitting device was obtained in the same manner as in Example 6, except that the comparative compound (3) used in Comparative Example 3 was used instead of the compound (4) used in Example 6.

[0215] The current efficiency of the obtained organic light-emitting device was measured using an ITO electrode as the anode and an Al electrode as the cathode. ２ The current efficiency at a current density of 50 mA / cm was 53.0 cd / A. ２ The current efficiency was 40.5 cd / A.

[0216] Comparative Example 9 An organic light-emitting device was obtained in the same manner as in Example 6, except that the comparative compound (5) used in Comparative Example 5 was used instead of the compound (4) used in Example 6.

[0217] The current efficiency of the obtained organic light-emitting device was measured using an ITO electrode as the anode and an Al electrode as the cathode. ２ The current efficiency at a current density of 50 mA / cm was 56.8 cd / A. ２ The current efficiency was 42.3 cd / A.

[0218]

[0219] As described above, the organometallic complex according to the present invention is an organometallic complex with excellent roll-off properties, in which the rate of decrease in luminous efficiency at a second current density higher than the first current density is small compared to the luminous efficiency at a first current density.

[0220] The present invention is not limited to the above-described embodiments, and various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the following claims are appended to apprise the public of the scope of the present invention.

[0221] This application claims priority based on Japanese Patent Application No. 2021-112295, filed on July 6, 2021, the entire contents of which are incorporated herein by reference.

[0222] REFERENCE SIGNS LIST 1 Interlayer insulating layer 2 Reflective electrode 3 Insulating layer 4 Organic compound layer 5 Transparent electrode 6 Protective layer 7 Color filter 10 Subpixel 11 Substrate 12 Insulating layer 13 Gate electrode 14 Gate insulating film 15 Semiconductor layer 16 Drain electrode 17 Source electrode 18 Thin film transistor 19 Insulating film 20 Contact hole 21 Lower electrode 22 Organic compound layer 23 Upper electrode 24 First protective layer 25 Second protective layer 26 Organic light-emitting element 100 Display device 1000 Display device 1001 Upper cover 1002 Flexible printed circuit 1003 Touch panel 1004 Flexible printed circuit 1005 Display panel 1006 Frame 1007 Circuit board 1008 Battery 1009 Lower cover 1100 Imaging device 1101 Viewfinder 1102 Rear display 1103 Operation unit 1104 Housing 1200 Electronic device 1201 Display unit 1202 Operation unit 1203 Housing 1300 Display device 1301 Frame 1302 Display unit 1303 Base 1310 Display device 1311 First display unit 1312 Second display unit 1313 Housing 1314 Bend point 1400 Illumination device 1401 Housing 1402 Light source 1403 Circuit board 1404 Optical film 1405 Light diffusion unit 1500 Automobile 1501 Tail lamp 1502 Window 1503 Vehicle body 1600 Smart glasses 1601 Lens 1602 Imaging device 1603 Control device 1610 Smart glasses 1611 Lens 1612 control device

Claims

1. An organometallic complex characterized by being represented by the following general formula (1). 【Chemical Formula 1】 In general formula (1), M is a metal atom, selected from Ir, Pt, Os, Rh, Pd, Ru. R １ to R ８ are each independently selected from a hydrogen atom or a substituent. The substituent is any one of a halogen atom, a cyano group, a nitro group, a trialkylsilyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, or a substituted or unsubstituted aryl group having two or fewer rings. R ９ to R １０ are each independently selected from a hydrogen atom and an alkyl group having 2 or fewer carbon atoms. However, at least one of R １ to R ８ is the above-mentioned substituent, or at least one of R ９ and R １０ is the above-mentioned alkyl group having 2 or fewer carbon atoms. R5 to R8 are a hydrogen atom or the above-mentioned alkyl group.

2. An organometallic complex represented by the following general formula (1). 【Chemical Formula 2】 In general formula (1), M is a metal atom, selected from Ir, Pt, Os, Rh, Pd, Ru. R １ , R ２ , R ４ to R ８ are each independently selected from a hydrogen atom or a substituent. The substituent is any one of a halogen atom, a cyano group, a nitro group, a trialkylsilyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, or a substituted or unsubstituted phenyl group. R ３ is selected from a hydrogen atom, a halogen atom, a cyano group, a nitro group, a trialkylsilyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, and a substituted or unsubstituted aryl group. R ９ to R １０is independently selected from a hydrogen atom and an alkyl group having 2 or fewer carbon atoms. However, R １ to R ８ is not a hydrogen atom, or at least one of R ９ and R １０ is the alkyl group having 2 or fewer carbon atoms. However, R5 to R8 are a hydrogen atom or the alkyl group.

3. An organometallic complex characterized by being represented by the following general formula (1). 【Chemical Formula 3】 In the general formula (1), M is a metal atom and is selected from Ir, Pt, Os, Rh, Pd, and Ru. R １ to R ８ are each independently selected from a hydrogen atom or a substituent. The substituent is any one of a halogen atom, a cyano group, a nitro group, a trialkylsilyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, or a substituted or unsubstituted aryl group. R ９ to R １０ are each independently selected from a hydrogen atom and an alkyl group having 2 or fewer carbon atoms. However, at least one of R ９ and R １０ is the alkyl group having 2 or fewer carbon atoms. R5 to R8 are a hydrogen atom or the alkyl group.

4. R １ to R ４ are each independently selected from a hydrogen atom or the alkyl group, according to any one of claims 1 to 3 of the organometallic complex described.

5. R ９ is the alkyl group having 2 or fewer carbon atoms, according to any one of claims 1 to 4 of the organometallic complex described.

6. R ９ and R １０ are both hydrogen atoms, according to claim 1 or 2 of the organometallic complex described.

7. R ３ The organometallic complex according to any one of claims 1 to 6, wherein R is a tert-butyl group.

8. The organometallic complex according to any one of claims 1 to 7, wherein the metal atom is Ir.

9. The organometallic complex according to any one of claims 1 to 8, which is any one of the following structural formulas (1) to (5). [Chemical Formula 4]

10. An organic light-emitting device having a first electrode, a second electrode, and an organic compound layer disposed between the first electrode and the second electrode, The organic compound layer has the organometallic complex according to any one of claims 1 to 9. The organic light-emitting device is characterized by this.

11. The organic compound layer is a light-emitting layer, and the light-emitting layer further has a first organic compound, The first organic compound is a compound having a lowest excited triplet energy higher than that of the organometallic complex. The organic light-emitting device according to claim 10 is characterized by this.

12. The light-emitting layer further has a second organic compound, and the lowest excited triplet energy of the second organic compound is equal to or higher than the lowest excited triplet energy of the organometallic complex and equal to or lower than the lowest excited triplet energy of the first organic compound. The organic light-emitting device according to claim 11 is characterized by this.

13. The organic compound layer further has a first charge transport layer disposed between the first electrode and the light-emitting layer, and a second charge transport layer disposed between the second electrode and the light-emitting layer, The first electrode is in contact with the first charge transport layer, and the second electrode is in contact with the second charge transport layer. The organic light-emitting device according to claim 11 or 12 is characterized by this.

14. The lowest excited triplet energy of the first charge transport layer is greater than the lowest excited triplet energy of the first organic compound, and the lowest excited triplet energy of the second charge transport layer is greater than the lowest excited triplet energy of the first organic compound. The organic light-emitting device according to claim 13, characterized in that.

15. A display device having a plurality of pixels, wherein at least one of the plurality of pixels includes the organic light-emitting device according to any one of claims 10 to 14 and a transistor connected to the organic light-emitting device.

16. An imaging device having an optical unit having a plurality of lenses, an imaging element that receives light that has passed through the optical unit, and a display unit that displays an image captured by the imaging element. The display unit has the organic light-emitting device according to any one of claims 10 to 14. The imaging device is characterized by this.

17. An electronic device having a display unit having the organic light-emitting device according to any one of claims 10 to 14, a housing in which the display unit is provided, and a communication unit provided in the housing and communicating with the outside.

18. A lighting device having a light source having the organic light-emitting device according to any one of claims 10 to 14 and a light diffusing unit or an optical film that transmits light emitted by the light source.

19. A moving body having a lighting fixture having the organic light-emitting device according to any one of claims 10 to 14 and a body in which the lighting fixture is provided.

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