Iridium complexes, organic light-emitting devices, display devices, imaging devices, electronic devices, lighting devices, and mobile bodies.

Abstract

To provide an iridium complex with a specific ligand structure and a small permanent dipole moment.SOLUTION: The present disclosure provides an iridium complex represented by general formula [1] or the like and having a permanent dipole moment of 1.5 or less. In the formula, R1 to R19 are H, halogen, or the like; and CY1 is phenyl or the like.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This disclosure relates to highly durable iridium complexes, organic light-emitting devices, display devices, imaging devices, electronic devices, lighting devices, and mobile devices having the same. [Background technology]

[0002] An organic light-emitting element (also called an organic electroluminescent element (organic EL element)) is an electronic element having a pair of electrodes and an organic compound layer placed between these electrodes. By injecting electrons and holes from this pair of electrodes, excitons of the light-emitting organic compound in the organic compound layer are generated, and when these excitons return to the ground state, the organic light-emitting element emits light.

[0003] Recent advances in organic light-emitting devices are remarkable, enabling low drive voltage, diverse emission wavelengths, fast response times, and miniaturization and weight reduction of light-emitting devices.

[0004] Currently, phosphorescence is being proposed as an attempt to improve the luminous efficiency of organic light-emitting diodes (OLEDs). Theoretically, OLEDs using phosphorescence are expected to have approximately four times the luminous efficiency of those using fluorescence. Therefore, there has been a great deal of effort to create phosphorescent organometallic complexes. This is because creating organometallic complexes with excellent luminescence properties is crucial for providing high-performance organic light-emitting devices. Furthermore, it has recently become known that controlling the molecular orientation of the light-emitting material is also important for improving the light extraction efficiency of the device.

[0005] As organometallic complexes created to date, the following compounds 1-a are described in Patent Document 1, and the following compounds 2-a and 2-b are described in Patent Document 2.

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[0008] [Chemical Formula] [Prior Art Documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-114137 [Patent Document 2] Japanese Patent Application Laid-Open No. 2020-164863 [Summary of the Invention] [Problems to be Solved by the Invention]

[0010] The exemplary compounds described in Patent Document 1 are organometallic compounds having a main ligand with a benzoisoquinoline skeleton. In these exemplary compounds, since the molecular volume is small and the permanent dipole moment of the molecule is large, there is room for improvement in the control of molecular orientation.

[0011]

[0012] The exemplary compounds described in Patent Document 2 are organometallic compounds having a main ligand with a benzoisoquinoline skeleton or a C5-C60 carbocyclic group or a C1-C60 heterocyclic group bonded by Ir-C and having at least one fluoro group (-F). However, since the permanent dipole moment is large, there is room for improvement in the control of molecular orientation. [Means for Solving the Problems]

[0013] The present invention provides an organic compound characterized by being represented by the following general formula.

[0014] <000;0104> [Chemical Formula]

[0015] [ka]

[0016] In general formulas (1) and (2), R 1 ~R 21 The group is independently selected from hydrogen atoms, deuterium atoms, halogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heterocyclic groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, cyano groups, and silyl groups. CY1 is a benzene ring (phenyl group), a naphthalene ring (naphthyl group), or a heterocyclic group having 4 to 10 carbon atoms. Furthermore, CY1 is a group represented by one of the chemical formulas [3-1] to [3-3] shown below.

[0017] In chemical formulas [3-1] to [3-3], R 22 ~R 27 X1 to X6 are independently selected from hydrogen atoms, deuterium atoms, halogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heterocyclic groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted amino groups, cyano groups, and silyl groups.

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[0020] [ka] [Effects of the Invention]

[0021] According to the present invention, it is possible to provide iridium complexes with a small permanent dipole moment and organic light-emitting devices with high luminescence efficiency. [Brief explanation of the drawing]

[0022] [Figure 1] (a) A schematic cross-sectional view showing an example of a pixel of a display device according to one embodiment of the present invention. (b) A schematic cross-sectional view showing an example of a display device using an organic light-emitting element according to one embodiment of the present invention. [Figure 2] This is a schematic diagram illustrating an example of a display device according to one embodiment of the present invention. [Figure 3] (a) A schematic diagram showing an example of an imaging device according to one embodiment of the present invention. (b) A schematic diagram showing an example of an electronic device according to one embodiment of the present invention. [Figure 4] (a) A schematic diagram showing an example of a display device according to one embodiment of the present invention. (b) A schematic diagram showing an example of a foldable display device. [Figure 5] (a) A schematic diagram showing an example of a lighting device according to one embodiment of the present invention. (b) A schematic diagram showing an example of an automobile having a vehicle light fixture according to one embodiment of the present invention. [Figure 6] (a) A schematic diagram showing an example of a wearable device according to one embodiment of the present invention. (b) A schematic diagram showing an example of a wearable device according to one embodiment of the present invention, which includes an imaging device. [Modes for carrying out the invention]

[0023] The present invention relates to an organic compound represented by the following general formula.

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[0026] In general formulas (1) and (2), R 1 ~R 21 Each of these groups is independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted amino group, a cyano group, and a silyl group.

[0027] CY1 is a group represented by one of the following chemical formulas [3-1] to [3-3]. In chemical formulas [3-1] to [3-3], R 22 ~R 27 X1 to X6 are independently selected from hydrogen atoms, deuterium atoms, halogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heterocyclic groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted amino groups, cyano groups, and silyl groups.

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[0031] In this specification, halogen atoms include, but are not limited to, fluorine, chlorine, bromine, and iodine.

[0032] In this specification, alkyl groups include alkyl groups having 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and even more preferably 1 to 4 carbon atoms. Specifically, examples include, but are not limited to, methyl groups, ethyl groups, n-propyl groups, isopropyl groups, n-butyl groups, tert-butyl groups, secondary butyl groups, octyl groups, cyclopentyl groups, cyclohexyl groups, 1-adamantyl groups, and 2-adamantyl groups.

[0033] In this specification, the alkoxy group is an alkoxy group having 1 to 10 carbon atoms, more preferably having 1 to 6 carbon atoms, and even more preferably having 1 to 4 carbon atoms. Specifically, examples include, but are not limited to, a methoxy group, an ethoxy group, a propoxy group, a 2-ethyl-xyloxy group, a benzyloxy group, etc.

[0034] In this specification, an amino group may be unsubstituted or substituted with an alkyl group, an aryl group, or an amino group. Alkyl groups, aryl groups, and amino groups may have halogen atoms as substituents. Aryl groups and amino groups may have alkyl groups as substituents. The substituted alkyl groups of the amino group may be bonded to each other to form a ring. Specifically, examples include, but are not limited to, N-methylamino group, N-ethylamino group, N,N-dimethylamino group, N,N-diethylamino group, N-methyl-N-ethylamino group, N-benzylamino group, N-methyl-N-benzylamino group, N,N-dibenzyloamino group, anilino group, N,N-diphenylamino group, N,N-dinaphthylamino group, N,N-difluorenylamino group, N-phenyl-N-tolylamino group, N,N-ditolylamino group, N-methyl-N-phenylamino group, N,N-dianisorylamino group, N-mesityl-N-phenylamino group, N,N-dimesitylamino group, N-phenyl-N-(4-tert-butylphenyl)amino group, N-phenyl-N-(4-trifluoromethylphenyl)amino group, N-piperidyl group, etc.

[0035] In this specification, the aryl group refers to an aryl group having 6 to 18 carbon atoms. Specifically, this includes the phenyl group, naphthyl group, indenyl group, biphenyl group, terphenyl group, fluorenyl group, phenanthryl group, triphenylenyl group, and the like.

[0036] In this specification, heterocyclic groups include heterocyclic groups having 3 to 15 carbon atoms. Heterocyclic groups may have nitrogen, sulfur, and oxygen as heteroatoms. Specifically, examples include, but are not limited to, pyridyl groups, pyrazyl groups, pyrimidyl groups, triazyl groups, imidazolyl groups, oxazolyl groups, oxadiazolyl groups, thiazolyl groups, thiadiazolyl groups, carbazolyl groups, acridinyl groups, phenantrolyl groups, furanyl groups, thiophenyl groups, dibenzofuranyl groups, and dibenzothiophenyl groups.

[0037] In this specification, the aryloxy group includes, but is not limited to, a phenoxy group and a thienyloxy group.

[0038] In this specification, silyl groups include, but are not limited to, trimethylsilyl groups and triphenylsilyl groups.

[0039] The alkyl groups, alkoxy groups, amino groups, aryl groups, heterocyclic groups, and aryloxy groups mentioned above may have halogen atoms as substituents. Examples of halogen atoms include fluorine, chlorine, bromine, and bromine, and may be fluorine atoms. In particular, alkyl groups may be methyl trifluoride groups by having a fluorine atom.

[0040] The above amino groups, aryl groups, heterocyclic groups, and aryloxy groups may have alkyl groups as substituents. The alkyl group may have 1 to 10 carbon atoms. More specifically, it may be a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, or a tert-butyl group.

[0041] The alkyl, alkoxy, amino, aryl, heterocyclic, and aryloxy groups mentioned above may have an aryl group as a substituent. The aryl group may have 6 to 12 carbon atoms. More specifically, it may be a phenyl group, a biphenyl group, or a naphthyl group.

[0042] The alkyl groups, alkoxy groups, amino groups, aryl groups, heterocyclic groups, and aryloxy groups mentioned above may have heterocyclic groups as substituents. The heterocyclic group may have 3 to 9 carbon atoms. The heterocyclic group may have nitrogen, sulfur, and oxygen as heteroatoms. More specifically, it may be a pyridyl group or a pyrrolyl group.

[0043] The alkyl groups, alkoxy groups, amino groups, aryl groups, heterocyclic groups, and aryloxy groups mentioned above may have an amino group as a substituent. The amino group may have an alkyl group or an aryl group, and the alkyl groups may be bonded to each other to form a ring. Specifically, these may be a dimethylamino group, a diethylamino group, a dibenzylamino group, a diphenylamino group, or a dicylamino group.

[0044] The alkyl groups, alkoxy groups, amino groups, aryl groups, heterocyclic groups, and aryloxy groups described above may have substituents such as aralkyl groups (e.g., benzyl groups), alkoxy groups (e.g., methoxy groups, ethoxy groups, propoxy groups), aryloxy groups (e.g., phenoxy groups), cyano groups, etc. However, the substituents are not limited to these.

[0045] ≪Iridium complex according to the present invention≫ The iridium complex according to the present invention exhibits high molecular orientation of the light-emitting material in the light-emitting layer of an organic light-emitting device, thereby improving the luminescence efficiency of the organic EL device. Here, molecular orientation in the present invention refers to the alignment of the transition dipole moments of the light-emitting molecules (iridium complex) doped into the host molecule in the light-emitting layer of the organic light-emitting device in a direction horizontal to the substrate surface of the organic light-emitting device. At this time, the permanent dipole moment of the light-emitting molecule is perpendicular to the substrate. Since the direction of light emission from the light-emitting molecule is mainly perpendicular to the transition dipole moment of that molecule, in the case of a light-emitting material with high molecular orientation, light loss due to substrate modes, waveguide modes, and surface plasmon polariton modes is reduced, and the outcoupling mode (light extraction efficiency) is improved.

[0046] The inventors have found that light-emitting materials with a small permanent dipole moment, where the para position relative to the nitrogen atom (N) of a benzoisoquinoline ligand or naphthoisoquinoline ligand is a benzene ring, naphthalene ring, or heterocyclic group, exhibit high molecular orientation and high luminescence efficiency in the light-emitting layer of organic light-emitting devices.

[0047] The orientation of a luminescent molecule is thought to be determined by which of two types of interactions, nonpolar or polar, is dominant between the luminescent molecule and the host molecule. Here, the dipole-dipole interaction, which is the main factor in the polar interaction between the luminescent molecule and the host molecule, is expressed by equation (1).

[0048]

number

[0049] However, μ1, μ2, and r represent the dipole moment of the luminescent molecule, the dipole moment of the host molecule, and the direction vector connecting the centers of mass of both molecules, respectively. Therefore, the polar interaction between the luminescent molecule and the host molecule increases as the permanent dipole moment increases, and decreases as the molecular volume and molecular weight of the luminescent molecule increase, due to the increased intermolecular distance.

[0050] Furthermore, host molecules consisting of a ring structure possess a permanent dipole moment, and both this permanent dipole moment and the ring structure are oriented horizontally to the substrate surface. When the permanent dipole moment per unit volume or per unit molecular weight of the luminescent molecule is large, polar interactions predominantly act between the luminescent molecule and the host molecule. Therefore, the luminescent molecule is oriented so that its permanent dipole moment aligns with the permanent dipole moments of the numerous host molecules surrounding it. In other words, when used with a host molecule consisting of a ring structure, the permanent dipole moment of the luminescent molecule is horizontal to the substrate surface. That is, it is not perpendicular to the substrate surface, so many components of the luminescent molecule have a light extraction direction that is not perpendicular to the substrate. On the other hand, when the permanent dipole moment per unit volume or per unit molecular weight of the luminescent molecule is small, nonpolar interactions predominantly act between the luminescent molecule and the host molecule. In that case, the molecular orientation is determined to maximize the nonpolar interaction. In the iridium complex according to the present invention, the luminescent molecule is oriented such that the benzoisoquinoline ligand or naphthisoquinoline ligand in the ligand, which is the largest ring structure of the luminescent molecule, is parallel to the ring structure of the host molecule. The transition dipole moment is in the direction connecting the iridium atom and the nitrogen atom of the benzoisoquinoline ligand or naphthisoquinoline ligand, that is, it is horizontal to the iridium atom and the benzoisoquinoline ligand or naphthisoquinoline ligand. In this case, the transition dipole moment in the luminescent molecule is aligned horizontally with respect to the ring structure of the host molecule and the substrate surface. In other words, the luminescent molecule is in a desirable molecular orientation state and has high molecular orientation.

[0051] Therefore, by using an organometallic compound represented by the general formula [1] or [2] described above as the light-emitting material in an organic light-emitting device, high molecular orientation and high luminescence efficiency can be achieved.

[0052] The permanent dipole moment of the iridium complex according to the present invention is preferably 1.5 or less, and more preferably a luminescent material with a permanent dipole moment of 1.0 or less. As a result of the small permanent dipole moment, the degree of orientation is preferably 90% or more, and more preferably 92% or more.

[0053] Here, the permanent dipole moments of organometallic compounds represented by general formulas [1] and [2] can be determined by calculations based on density functional theory, using the functional B3PW91 and the basis set LANL2DZ. For example, the calculation can be performed using Gaussian09, Revision D.01. The permanent dipole moment obtained by calculation is sometimes called the calculated permanent dipole moment value.

[0054] Gaussian 09, Revision D.01, M.J. Frisch, G.W. Trucks, H.B. Schlegel, G.E. Scuseria, M.A. Robb, J.R. Cheeseman, G. Scalmani, V. Barone, B. Mennucci, G.A. Petersson, H. Nakatsuji, M. Caricato, X. Li, H.P. Hratchian, A.F. Izmaylov, J. Bloino, G. Zheng, J.L. Sonnenberg, M. Hada, M. Ehara, K. Toyota, R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda, O. Kitao, H. Nakai, T. Vreven, J.A. Montgomery, Jr., J.E. Peralta, F. Ogliaro, M. Bearpark, J.J. Heyd, E. Brothers, K.N. Kudin, V.N. Staroverov, T. Keith, R. Kobayashi, J. Normand, K. Raghavachari, A. Rendell, J.C. Burant, S.S. Iyengar, J. Tomasi, M. Cossi, N. Rega, J.M. Millam, M. Klene, J.E. Knox, J.B. Cross, V. Bakken, C. Adamo, J. Jaramillo, R. Gomperts, R.E. Stratmann, O. Yazyev, A.J. Austin, R. Cammi, C. Pomelli, J.W. Ochterski, R.L. Martin, K. Morokuma, V.G. Zakrzewski, G.A. Voth, P. Salvador, J.J. Dannenberg, S. Dapprich, A.D. Daniels, O. Farkas, J.B. Foresman, J.V. Ortiz, J. Cioslowski, and D.J. Fox, Gaussian, Inc., Wallingford CT, 2013.

[0055] In the benzoisoquinoline skeleton of general formula [1] and the naphthoisoquinoline skeleton of general formula [2], at a specific position (R 12We have found that by introducing a strongly electron-withdrawing substituent to the organic light-emitting element, the permanent dipole moment can be reduced, thereby improving the luminescence efficiency. This electron-withdrawing property can be expressed by the Hammett constant σp, and by providing an electron-withdrawing substituent with a para-Hammett constant σp of 0.5 or higher, the luminescence efficiency of the organic light-emitting element can be improved. Among these, -CF3, -CN, -COF, -CF(CF3)2, -OCF3, and -SiF3 are preferred, and -CF3 is particularly preferred.

[0056] Furthermore, it is preferable that the skeleton is a benzoisoquinoline skeleton represented by general formula [1], and CY1 is preferably a benzene ring (phenyl group) or a naphthalene ring (naphthyl group), and more preferably a benzene ring (phenyl group).

[0057] The iridium complex according to the present invention is R 17 and R 19 However, it is preferably a substituted or unsubstituted alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, and particularly preferably a methyl group. 1 ~R 7 It is preferably a substituted or unsubstituted alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, and each independently of R 1 , R 3 , R 4 , R 6 is an ethyl group, R 2 , R 5 is a methyl group, R 7 It is particularly preferable that the atom is a hydrogen atom.

[0058] Considering the above, the iridium complex represented by the following structural formula is particularly preferred.

[0059] [ka]

[0060] This iridium complex has a phenylbenzoisoquinoline skeleton with a benzene ring substituent, a CF3 group at the para position as an electron-withdrawing substituent, and two methyl groups attached to the phenyl group bonded to the iridium atom. Furthermore, the ligand containing an oxygen atom, called an auxiliary ligand, is provided with an ethyl group (a two-carbon alkyl group) and a methyl group (a one-carbon alkyl group). These alkyl groups may be replaced with hydrogen atoms. By providing specific substituents at specific ligand positions in this way, the luminescence efficiency of the device can be improved.

[0061] The iridium complex according to the present invention may be an ink composition used with a solvent. The solvent may be a solvent that disperses or dissolves the iridium complex. The ink composition may be luminescent.

[0062] One embodiment of the present invention is an ink composition having the iridium complex, the first organic compound, and a solvent. The first organic compound is preferably a host. When the host is a polymer, the host can be a block copolymer, random copolymer, alternating copolymer, graft copolymer, etc. Examples of solvents include halogenated hydrocarbon solvents such as chloroform, dichloroethane, tetrachloroethane, chlorobenzene, and o-dichlorobenzene; ether solvents such as tetrahydrofuran and ethylene glycol dimethyl ether; aromatic hydrocarbon solvents such as toluene, xylene, and mesitylene; aliphatic hydrocarbon solvents such as n-heptane, isoheptane, and methylcyclohexane; ketone solvents such as methyl ethyl ketone, 2-heptanone, and cyclohexanone; ester solvents such as ethyl acetate, butyl acetate, γ-butyrolactone, and γ-valerolactone; polyhydric alcohol solvents; alcohol solvents; sulfoxide solvents such as dimethyl sulfoxide and sulfolane; and amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and 1-methyl-2-pyrrolidone. These organic solvents can be used individually or in combination of two or more. Among these, it is preferable to use organic solvents with a moderate evaporation rate, specifically those with a boiling point of about 70 to 200°C, as these are more likely to produce thin films with uniform thickness.

[0063] The above ink composition can be formed into a film by methods such as spin coating, bar coating, slit coating, inkjet, nozzle coating, casting, and gravure printing.

[0064] The following are examples of iridium complexes according to the present invention, but the present invention is not limited to these.

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[0078] Organic light-emitting diodes Next, the organic light-emitting element of this embodiment will be described. The organic light-emitting element of this embodiment has at least a first electrode, a second electrode, and an organic compound layer disposed between these electrodes. One of the first electrode and the second electrode is the anode and the other is the cathode. In the organic light-emitting element 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. If the organic compound layer is a laminate consisting of multiple layers, the organic compound layer may have, in addition to the light-emitting layer, 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. Furthermore, the light-emitting layer may be a single layer or a laminate consisting of multiple layers.

[0079] In the organic light-emitting element of this embodiment, at least one layer of the organic compound layer contains the iridium complex according to this embodiment. Specifically, the organic compound according to this embodiment is included in any of the above-mentioned light-emitting layer, hole implantation layer, hole transport layer, electron blocking layer, hole exciton blocking layer, electron transport layer, electron implantation layer, etc. The organic compound according to this embodiment is preferably included in the light-emitting layer.

[0080] In the organic light-emitting element of this embodiment, when the organic compound according to this embodiment is included in the light-emitting layer, the light-emitting layer may consist only of the organic compound according to this embodiment, or it may consist of the organometallic complex according to this embodiment and other compounds. Here, when the light-emitting layer consists of the organometallic complex according to this embodiment and other compounds, the organic compound according to this embodiment may be used as a host or a guest in the light-emitting layer. It may also be used as an assist material that can be included in the light-emitting layer. Here, the host is the compound with the largest mass ratio among the compounds constituting the light-emitting layer. The guest is a compound with a smaller mass ratio than the host among the compounds constituting the light-emitting layer, and is responsible for the main light emission. The assist material is a compound with a smaller mass ratio than the host among the compounds constituting the light-emitting layer, and assists the light emission of the guest. The assist material is also called the second host. The host material can also be called the first compound, and the assist material can be called the second compound.

[0081] When the organic compound according to this embodiment is used as a guest in the light-emitting layer, the concentration of the guest is preferably 0.01% by mass or more and 20% by mass or less, and more preferably 0.1% by mass or more and 10% by mass or less, relative to the entire light-emitting layer.

[0082] The light-emitting layer according to this embodiment comprises an iridium complex and a first organic compound, wherein the first organic compound can be a compound with a lower minimum excitation singlet energy greater than that of the iridium complex. The first organic compound is also called a host. The weight ratio of the host in the light-emitting layer may be greater than that of the iridium complex.

[0083] Furthermore, the luminescent layer may contain a second organic compound different from the first organic compound. The second organic compound can be a compound whose lowest excitation triplet energy is lower than that of the first organic compound and higher than that of the iridium complex. The second organic compound is also called the assist. The assist may have a smaller weight ratio in the luminescent layer than the host, and its weight ratio in the luminescent layer may be smaller than that of the iridium complex.

[0084] The inventors conducted various studies and found that when the organic compound according to this embodiment is used as a host or guest for the light-emitting layer, particularly as a guest for the light-emitting layer, a device can be obtained that exhibits high efficiency, high brightness, and extremely high durability. This light-emitting layer may be a single layer or a multi-layer, and it is also possible to mix the light emission with the red light emission of this embodiment by including a light-emitting material having another light emission color. A multi-layer means a state in which one light-emitting layer and another light-emitting layer are stacked. In this case, the light emission color of the organic light-emitting element is not limited to red. More specifically, it may be white or an intermediate color. In the case of white, the other light-emitting layer emits a color other than red, i.e., blue or green. Furthermore, the film is formed by vapor deposition or coating. Details of this will be explained in detail in the examples described later.

[0085] The organometallic complex according to this embodiment can be used as a constituent material for organic compound layers other than the light-emitting layer constituting the organic light-emitting device of this embodiment. Specifically, it may be used as a constituent material for electron transport layers, electron injection layers, hole transport layers, hole injection layers, hole blocking layers, etc. In this case, the light-emitting color of the organic light-emitting device is not limited to red. More specifically, it may be white light or an intermediate color.

[0086] In addition to the organic compounds according to this embodiment, conventionally known low-molecular-weight and high-molecular-weight hole-injecting or hole-transporting compounds, host compounds, luminescent compounds, electron-injecting or electron-transporting compounds, etc., can be used together as needed. Examples of these compounds are listed below.

[0087] As hole-implantation transport materials, materials with high hole mobility are preferred to facilitate hole injection from the anode and to transport the injected holes to the light-emitting layer. Furthermore, materials with a high glass transition temperature are preferred to suppress deterioration of the film quality, such as crystallization, in the organic light-emitting element. Examples of low-molecular-weight and high-molecular-weight materials with hole-implantation transport properties include triarylamine derivatives, arylcarbazole derivatives, phenylenediamine derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, poly(vinylcarbazole), poly(thiophene), and other conductive polymers. Moreover, the above-mentioned hole-implantation transport materials are also suitably used in electron-blocking layers. Specific examples of compounds used as hole-implantation transport materials are shown below, but are not limited to these.

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[0091] In addition to organometallic complexes represented by general formula (1), luminescent materials primarily involved in light emission 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-quinolinolate)aluminum, iridium complexes, 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.

[0092] The following are some specific examples of compounds used as luminescent materials, but of course, they are not the only ones.

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[0096] Examples of light-emitting layer hosts or light-emitting assist materials included in the light-emitting layer include aromatic hydrocarbon compounds or their derivatives, as well as carbazole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, organoaluminum complexes such as tris(8-quinolinolate)aluminum, and organoberylium complexes.

[0097] The following are specific examples of compounds used as luminescent layer hosts or luminescence assist materials contained in the luminescent layer, but of course, they are not limited to these.

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[0101] As electron-transporting materials, any material capable of transporting electrons injected from the cathode to the light-emitting layer can be arbitrarily selected, taking into consideration the balance with the hole mobility of the hole-transporting material. Examples of materials with electron-transporting properties include oxadiazole 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 suitably used in the hole-blocking layer. Specific examples of compounds used as electron-transporting materials are shown below, but are of course not limited to these.

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[0104] The following describes the components other than the organic compound layer that constitute the organic light-emitting element of this embodiment. The organic light-emitting element may be provided on a substrate by forming a first electrode, an organic compound layer, and a second electrode. A protective layer, a color filter, etc., may be provided on the second electrode. If a color filter is provided, a planarization layer may be provided between it and the protective layer. The planarization layer can be made of acrylic resin or the like.

[0105] The substrate may be made of quartz, glass, silicon, resin, metal, or the like. The substrate may also be equipped with switching elements such as transistors and wiring, and an insulating layer may be provided on top of them. The insulating layer is not limited in material as long as it can form contact holes to ensure conductivity between the anode and the wiring, and provide insulation from unconnected wiring. For example, resins such as polyimide, silicon oxide, and silicon nitride can be used.

[0106] The anode material should ideally have a high work function. For example, elemental metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, and tungsten, or mixtures containing these, or alloys combining them, as well as metal oxides such as tin oxide, zinc oxide, indium oxide, tin-indium oxide (ITO), and zinc-indium oxide can be used. Conductive polymers such as polyaniline, polypyrrole, and polythiophene can also be used. These electrode materials may be used individually or in combination of two or more. The anode may consist of a single layer or multiple layers. When used as a reflective electrode, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, or alloys or laminates thereof can be used. When used as a transparent electrode, transparent conductive oxide layers such as indium-tin oxide (ITO) and indium-zinc oxide can be used, but are not limited to these. Photolithography can be used to form the anode.

[0107] On the other hand, materials with a small work function are preferred for the cathode. Examples include alkali metals such as lithium, alkaline earth metals such as calcium, and elemental metals or mixtures containing these, such as aluminum, titanium, manganese, silver, lead, and chromium. Alternatively, alloys combining these elemental metals can also 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 may be used individually or in combination of two or more. The cathode may also be a single-layer or multi-layer structure. Among these, silver is preferred, and a silver alloy is even more preferred in order to suppress silver aggregation. The ratio of the alloy is not important as long as silver aggregation is suppressed. For example, it may be 1:1.

[0108] The cathode may be a top-emission element using an oxide conductive layer such as 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 using DC and AC sputtering methods is more preferable because it provides good film coverage and makes it easier to reduce resistance.

[0109] A protective layer may be provided after cathode formation. For example, by bonding glass with a desiccant onto the cathode, the intrusion of water and other substances into the organic compound layer can be suppressed, thereby reducing the occurrence of display defects. In another embodiment, a passivation film such as silicon nitride may be provided on the cathode to suppress the intrusion of water and other substances into the organic compound layer. For example, after cathode formation, the material may be transported to another chamber without breaking the vacuum, and a silicon nitride film with a thickness of 2 μm may be formed by the CVD method to serve as a protective layer. A protective layer may also be provided using atomic deposition (ALD) after film formation by the CVD method.

[0110] Furthermore, a color filter may be provided for each pixel. For example, a color filter matching the size of the pixel may be provided on a separate substrate and bonded to the substrate provided on the organic light-emitting element, or the color filter may be patterned on a protective layer such as silicon dioxide using photolithography technology.

[0111] The organic compound layers constituting the organic light-emitting element according to this embodiment (hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, electron injection layer, etc.) are formed by the following methods. Specifically, dry processes such as vacuum deposition, ionization deposition, sputtering, and plasma can be used to form the organic compound layers. Alternatively, a wet process can be used instead of a dry process, in which the layer is formed by dissolving it in a suitable solvent and applying a known coating method (e.g., spin coating, dipping, casting, LB method, inkjet method, etc.). When a layer is formed by vacuum deposition or solution coating, crystallization is less likely to occur, resulting in excellent stability over time. When forming a film by coating, it is also possible to form a film by combining it with a suitable binder resin. Examples of binder resins include, but are not limited to, polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenolic resin, epoxy resin, silicone resin, and urea resin. Furthermore, the binder resin may be used alone as a homopolymer or copolymer, or as a mixture of two or more types. In addition, known additives such as plasticizers, antioxidants, and ultraviolet absorbers may be used in combination as needed.

[0112] <Device using organic light-emitting elements> The organic light-emitting element according to this embodiment can be used as a component of a display device or lighting device. Other applications include exposure light sources for electrophotographic image forming apparatuses, backlights for liquid crystal display devices, and light-emitting devices with a color filter in a white light source.

[0113] The display device may also be an image information processing device having an image input unit that receives image information from an area CCD, linear CCD, memory card, etc., an information processing unit that processes the input information, and displays the input image on the display unit. Furthermore, the display unit of an imaging device or inkjet printer may have a touch panel function. The driving method for this touch panel function may be infrared, capacitive, resistive, or electromagnetic induction, and is not particularly limited. The display device may also be used as the display unit of a multifunction printer.

[0114] By using the device employing the organic light-emitting element according to this embodiment, stable display with good image quality is possible even during long-term display.

[0115] <Display device> The display device according to this embodiment has a plurality of pixels, at least one of which has the organic light-emitting element of this embodiment. This pixel has the organic light-emitting element according to this embodiment and an active element. The display device may be used as the display unit of an image display device having an input unit for inputting image information and a display unit for outputting an image.

[0116] Figure 1 is a schematic cross-sectional view showing an example of a display device according to this embodiment.

[0117] Figure 1(a) is a schematic cross-sectional view of an example of a pixel constituting the display device according to this embodiment. The pixel has 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 emitted from the light-emitting layer, or the light emitted from the sub-pixel may be selectively transmitted or color-converted by a color filter or the like. Each sub-pixel has a reflective electrode 2 which is a first electrode, an insulating layer 3 covering the end 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 on an interlayer insulating layer 1.

[0118] The interlayer insulating layer 1 may have transistors and capacitive elements placed in the layer below or inside it. The transistor and the first electrode may be electrically connected via a contact hole or the like (not shown).

[0119] The insulating layer 3 is also called the bank or pixel isolation layer. It covers the edge of the first electrode and surrounds the first electrode. The portion without the insulating layer is in contact with the organic compound layer 4 and becomes the light-emitting region.

[0120] 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.

[0121] The second electrode 5 may be a transparent electrode, a reflective electrode, or a semi-transparent electrode.

[0122] The protective layer 6 reduces the penetration of moisture into the organic compound layer. Although the protective layer is shown as a single layer, it may consist of multiple layers. Each layer may contain an inorganic compound layer and an organic compound layer.

[0123] The color filters 7 are classified into 7R, 7G, and 7B according to their color. The color filters may be formed on a planarization film (not shown). The color filters may also have a resin protective layer (not shown). Alternatively, the color filters may be formed on a protective layer 6, or they may be bonded together after being placed on an opposing substrate such as a glass substrate.

[0124] Figure 1(b) is a schematic cross-sectional view showing an example of a display device having an organic light-emitting element and a transistor connected to this organic light-emitting element. The organic light-emitting element 26 has an anode 21, an organic compound layer 22, and a cathode 23. The transistor is an example of an active element. The transistor may be a thin-film transistor (TFT).

[0125] The display device 100 in Figure 1(b) has a substrate 11 made of glass, silicon, or the like, with an insulating layer 12 on top of it. An active element 18 such as a TFT is placed on the insulating layer, and the gate electrode 13, gate insulating film 14, and semiconductor layer 15 of the active element are arranged thereon. The TFT 18 is also composed of a semiconductor layer 15, a drain electrode 16, and a source electrode 17. An insulating film 19 is provided on top of the TFT 18. The anode 21 and the source electrode 17, which constitute an organic light-emitting element, are connected via a contact hole 20 provided in the insulating film.

[0126] Furthermore, the method of electrical connection between the electrodes (anode, cathode) included in the organic light-emitting element 26 and the electrodes (source electrode, drain electrode) included in the TFT is not limited to the configuration shown in Figure 1(b). In other words, it is sufficient for either the anode or cathode to be electrically connected to either the TFT source electrode or the drain electrode. TFT refers to a thin-film transistor.

[0127] In the display device 100 shown in Figure 1(b), the organic compound layer is depicted as a single layer, but the organic compound layer 22 may consist of multiple layers. A first protective layer 24 and a second protective layer 25 are provided on the cathode 23 to reduce the degradation of the organic light-emitting element.

[0128] In the display device 100 shown in Figure 1(b), a transistor is used as the switching element, but other switching elements may be used instead.

[0129] Furthermore, the transistor used in the display device 100 in Figure 1(b) is not limited to a transistor using a single-crystal silicon wafer, but may also be a thin-film transistor having an active layer on an insulating surface of the substrate. Examples of active layers include non-single-crystal silicon such as single-crystal silicon, amorphous silicon, and microcrystalline 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.

[0130] The transistors included in the display device 100 in Figure 1(b) may be formed within a substrate such as a Si substrate. Here, "formed within a substrate" means that the transistors are manufactured by processing the substrate itself, such as a Si substrate. In other words, having transistors within a substrate can be seen as the substrate and transistors being formed as a single unit.

[0131] The organic light-emitting element according to this embodiment has its luminescence controlled by a TFT, which is an example of a switching element, and by providing multiple organic light-emitting elements on the surface, an image can be displayed using the luminescence of each element. The switching element according to this embodiment is not limited to a TFT, but may also be a transistor made of low-temperature polysilicon, or an active matrix driver formed on a substrate such as a Si substrate. "On the substrate" can also mean "within the substrate." Whether to provide a transistor within the substrate or to use a TFT is selected depending on the size of the display area; for example, if the size is about 0.5 inches, it is preferable to provide the organic light-emitting element on a Si substrate.

[0132] The display device may have multiple light-emitting elements. Each light-emitting element may have a driving circuit. The driving circuit may be an active-matrix type that independently controls the light emission of the first light-emitting element and the second light-emitting element. The active-matrix circuit may be voltage-programmed or current-programmed. The driving circuit has a pixel circuit for each pixel. The pixel circuit may have a light-emitting element, a transistor that controls the light emission brightness of the light-emitting element, a transistor that controls the light emission timing, a capacitor that holds the gate voltage of the transistor that controls the light emission brightness, and a transistor for connecting to GND without going through the light-emitting element.

[0133] The light-emitting elements constituting the light-emitting device may have a distance of 10 μm, 7 μm, or 5 μm or less between each element.

[0134] Figure 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 the upper cover 1001 and the lower cover 1009. Flexible printed circuits FPCs 1002 and 1004 are connected to the touch panel 1003 and the display panel 1005. An organic light-emitting element according to this embodiment may be used in the display panel 1005. Transistors are printed on the circuit board 1007. The battery 1008 does not need to be provided if the display device is not a portable device, and even if it is a portable device, it does not need to be provided in this position.

[0135] <Imaging device> The display device according to this embodiment may be used as a display unit in a photoelectric conversion device such as an imaging device having an optical unit with multiple lenses and an image sensor that receives light that has passed through the optical unit. The photoelectric conversion device may have a display unit that displays information acquired by the image sensor. Furthermore, the display unit may be a display unit exposed to the outside of the photoelectric conversion device or a display unit located inside the viewfinder. The photoelectric conversion device may be a digital camera or a digital video camera.

[0136] Figure 3(a) is a schematic diagram showing 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 have a display device according to this embodiment. In that case, the display device may display not only the image to be captured, but also environmental information, imaging instructions, etc. Environmental information may include the intensity of ambient light, the direction of ambient light, the speed at which the subject is moving, the possibility of the subject being obscured by an obstruction, etc. Since the optimal timing for imaging is only a short time, it is better to display the information as quickly as possible. Therefore, it is preferable to use a display device using the organic light-emitting element of the present invention. This is because organic light-emitting elements have a fast response speed. A display device using an organic light-emitting element can be used more preferably than a liquid crystal display device in devices where a display speed is required. The imaging device 1100 has an optical section (not shown). The optical section has a plurality of lenses and forms an image on the image sensor housed in the housing 1104. The focus can be adjusted by adjusting the relative positions of the plurality of lenses. This operation can also be automated.

[0137] <Electronic equipment> The display device according to this embodiment may be used in the display unit of an electronic device such as a mobile terminal. In that case, it may have both a display function and an operation function. Examples of mobile terminals include smartphones and other mobile phones, tablets, and head-mounted displays.

[0138] Figure 3(b) shows an example of an electronic device having a display device according to this embodiment. The portable 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 response unit. The operation unit may also be a biometric recognition unit that recognizes fingerprints to unlock the device, etc. A portable device having a communication unit can also be called a communication device.

[0139] Figure 4 is a schematic diagram showing an example of a display device according to this embodiment. Figure 4(a) is 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 display unit 1302 may use an organic light-emitting element according to this embodiment. The display device 1300 also has a base 1303 that supports the frame 1301 and the display unit 1302. The base 1303 is not limited to the form shown in Figure 4(a). The lower edge of the frame 1301 may also serve as the base. The frame 1301 and the display unit 1302 may also be curved. The radius of curvature may be 5000 mm or more and 6000 mm or less.

[0140] The display device 1310 in Figure 4(b) is configured to be foldable 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 have organic light-emitting elements according to this embodiment. The first display unit 1311 and the second display unit 1312 may be a single display device without seams. The first display unit 1311 and the second display unit 1312 can be separated by a 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 together display a single image.

[0141] <Lighting equipment> Figure 5(a) is a schematic diagram showing an example of a lighting device according to this embodiment. The lighting device 1400 may include a housing 1401, a light source 1402, a circuit board 1403, an optical film 1404, and a light diffusion section 1405. The light source 1402 may have an organic light-emitting element according to this embodiment. The optical film 1404 may be a film that improves the color rendering of the light source 1402. The light diffusion section 1405 can effectively diffuse the light from the light source 1402, such as for lighting up, and deliver light over a wide area. A cover may be provided on the outermost part if necessary.

[0142] The lighting device is, for example, a device for illuminating a room. The lighting device may emit white light, daylight white light, or any other color from blue to red. It may have a dimming circuit to adjust the brightness of these lights. 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 that converts AC voltage to DC voltage. The lighting device may also have an inverter circuit. White light has a color temperature of 4200K, and daylight white light has a color temperature of 5000K. The lighting device may also have a color filter. Furthermore, the lighting device according to this embodiment may have a heat dissipation section. The heat dissipation section releases heat from inside the device to the outside, and examples include metals with high specific heat, liquid silicon, etc.

[0143] <Mobile> The mobile body according to this embodiment may be an automobile, ship, aircraft, drone, etc. The mobile 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 an organic light-emitting element according to this embodiment.

[0144] Figure 5(b) is a schematic diagram showing an example of a mobile body according to this embodiment, and shows an automobile having a taillight, which is an example of a vehicle light fixture. The automobile 1500 as the body has a taillight 1501, and may be configured to illuminate when the brakes are applied or the like. The taillight 1501 may have an organic light-emitting element according to this embodiment. The taillight 1501 may have a protective member to protect the organic light-emitting element. The protective member has a reasonably high strength and can be made of any material as long as it is transparent, but it is preferably made of polycarbonate or the like. A franciocarboxylic acid derivative, an acrylonitrile derivative, or the like may be mixed with the polycarbonate. The automobile 1500 may have a body 1503 and a window 1502 attached thereto. The window 1502 may be a transparent display, unless it is a window for checking the front and rear of the automobile 1500. The transparent display may have an organic light-emitting element according to this embodiment. In this case, the constituent materials such as electrodes of the organic light-emitting element are made of transparent material.

[0145] The mobile body according to this embodiment may be a ship, aircraft, drone, etc. The mobile 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 an organic light-emitting element according to this embodiment.

[0146] Referencing Figure 6, examples of applications of the display devices of each embodiment described above will be explained. 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 imaging display device used in such applications comprises an imaging device capable of photoelectric conversion of visible light and a display device capable of emitting visible light.

[0147] Figure 6(a) illustrates a pair of glasses 1600 (smart glasses) according to one application example. An imaging device 1602, such as a CMOS sensor or SPAD, is provided on the front surface of the lens 1601 of the glasses 1600. In addition, the display devices of each embodiment described above are provided on the back surface of the lens 1601.

[0148] The eyeglasses 1600 further include a control device 1603. The control device 1603 functions as a power supply that provides power to the imaging device 1602 and the display device according to each embodiment. The control device 1603 also controls the operation of the imaging device 1602 and the display device. The lens 1601 has an optical system formed therein for focusing light onto the imaging device 1602.

[0149] Figure 6(b) illustrates a pair of glasses 1610 (smart glasses) according to one application example. The glasses 1610 have a control device 1612, which is equipped with an imaging device equivalent to an imaging device 1602 and a display device. The lens 1611 has an optical system formed therein 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 supply to provide power to the imaging device and the display device, and also controls the operation of the imaging device and the display device. The control device may have a gaze detection unit that detects the wearer's gaze. Gaze detection may use infrared light. The infrared light emitter emits infrared light towards the eyeball of the user who is fixating on the displayed image. The imaging unit, which has a photodetector, detects the reflected light from the eyeball of the emitted infrared light, thereby obtaining an image of the eyeball. By having a reduction means that reduces the light from the infrared light emitter to the display unit in planar view, the degradation of image quality is reduced.

[0150] The user's gaze towards the displayed image is detected from an image of the eyeball obtained by imaging with infrared light. Any known method can be applied to gaze detection using an image of the eyeball. For example, a gaze detection method based on the Purkinje image obtained by the reflection of the irradiated light from the cornea can be used.

[0151] More specifically, gaze detection processing is performed based on the pupil-corneal reflection method. Using the pupil-corneal reflection method, a gaze vector representing the orientation (rotation angle) of the eyeball is calculated based on the pupil image and Purkinje image contained in the captured image of the eyeball, thereby detecting the user's gaze.

[0152] A display device according to one embodiment of the present invention includes an imaging device having a light-receiving element, and may control the display image of the display device based on the user's gaze information from the imaging device.

[0153] Specifically, the display device determines a first field of view that the user is fixated on, and a second field of view other than the first field of view, based on gaze information. The first and second field of view may be determined by the control device of the display device, or they may be determined by an external control device and received by the display device. Within the display area of ​​the display device, the display resolution of the first field of view may be controlled to be higher than the display resolution of the second field of view. In other words, the resolution of the second field of view may be lower than that of the first field of view.

[0154] Furthermore, the display area has a first display area and a second display area different from the first display area, and based on gaze information, the area with higher priority is determined from the first display area and the second display area. The first display area and the second display area may be determined by the control device of the display device, or they 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 the areas other than the high-priority area. In other words, the resolution of areas with relatively lower priority may be set lower.

[0155] AI may be used to determine the primary field of view and high-priority areas. The AI ​​may be a model configured to estimate the angle of gaze and the distance to the target object at the end of the line of sight from the image of the eye, using the image of the eye and the direction the eye was actually looking in that image as training data. The AI ​​program may be installed in the display device, the imaging device, or an external device. If installed in an external device, it will be transmitted to the display device via communication.

[0156] When display control is based on visual detection, this method is preferably applicable to smart glasses that further include an imaging device for capturing images of the surrounding environment. The smart glasses can display the captured external information in real time.

[0157] As described above, by using the device employing the organic light-emitting element according to this embodiment, stable display with good image quality is possible even during long-term display. [Examples]

[0158] Examples are described below. However, the present invention is not limited to these examples.

[0159] [Example 1] Synthesis of Exemplary Compound 8 The example compound 8 was synthesized as shown below.

[0160] [ka]

[0161] Under a nitrogen atmosphere, 59.64 g of 4-chlorophenylboronic acid, 100.00 g of 2-chloro-3-formyl-4-iodopyridine, 800 mL of toluene, 250 mL of ethanol, 600 mL of water, and 79.26 g of sodium carbonate were added to a 2000 mL round-bottom flask. The temperature was raised from room temperature to 90 °C and stirred for 6 hours. Toluene and water were added, and magnesium sulfate was added to the organic layer extracted from the organic layer, which was then filtered. After concentration, the mixture was washed with methanol to obtain 85.61 g of intermediate 1 (90% yield). The structure is 1 Identification was performed using 1H-NMR and GC-MS.

[0162] [ka]

[0163] Under a nitrogen atmosphere, 114.22 g of (methoxymethyl)triphenylphosphonium chloride and 560 mL of anhydrous THF were added to a 1000 mL three-necked round-bottom flask and stirred. While cooling the reaction vessel in an ice bath, 44.89 g of tert-butoxypotassium was added in small amounts in powder form and stirred for 30 minutes in the ice bath. After 30 minutes, 56.00 g of intermediate 1 was added in powder form and stirred for 1 hour at room temperature. Toluene and water were added, and magnesium sulfate was added to the extracted organic layer and filtered. After concentration, column purification with toluene was performed to obtain 74.20 g of intermediate 2 (yield 88%). The structure is 1 Identification was performed using 1H-NMR and GC-MS.

[0164] [ka]

[0165] Under a nitrogen atmosphere, 195 ml of trifluoromethanesulfonic acid and 930 ml of dichloromethane were added to a 2000 mL round-bottom flask. While cooling the reaction vessel in an ice bath, 62.00 g of intermediate 2 was added dropwise. After returning the temperature to room temperature and stirring for 2 hours, the mixture was neutralized with aqueous sodium hydroxide solution, and the organic layer was extracted using dichloromethane and water. Magnesium sulfate was added to the resulting organic layer, and after filtration and concentration, the resulting solid was washed with methanol to obtain 41.73 g of intermediate 3 (yield 76%). The structure is 1 Identification was performed using 1H-NMR and GC-MS.

[0166] [ka]

[0167] Under a nitrogen atmosphere, 20.00 g of intermediate 3, 11.44 g of 3,5-dimethylphenylboronic acid, 0.86 g of tetrakistriphenylphosphine palladium, 160 mL of toluene, 50 mL of ethanol, 120 mL of water, and 15.85 g of sodium carbonate were added to a 500 mL round-bottom flask. The temperature was raised from room temperature to 90 °C and stirred for 3 hours. After the reaction was complete, toluene and water were added to extract the organic layer, and magnesium sulfate was added to the resulting organic layer and filtered. After concentration, the obtained residue was column purified with toluene and then washed with methanol to obtain 24.00 g of intermediate 4 (yield 93%). The structure is 1 Identification was performed using 1H-NMR and LC-MS.

[0168] [ka]

[0169] Under a nitrogen atmosphere, 16.00 g of intermediate 4, 10.52 g of 4-trifluoromethylphenylboronic acid, 1.13 g of palladium acetate, 6.20 g of SPos, 24.04 g of potassium phosphate, 240 mL of 1,4-dioxane, and 80 mL of water were added to a 500 mL round-bottom flask. The temperature was raised from room temperature to 90 °C and stirred for 2 hours. After the reaction was complete, water was added, and the precipitated solid was filtered. The obtained solid was washed with methanol and water. Subsequently, column purification with toluene was performed to obtain 17.45 g of intermediate 5 (yield 81%). The structure is 1 Identification was performed using 1H-NMR and LC-MS.

[0170] [ka]

[0171] Under a nitrogen atmosphere, 16.00 g of intermediate 5, 6.44 g of iridium chloride trihydrate, 206 mL of 2-ethoxyethanol, and 103 mL of water were added to a 500 mL round-bottom flask. The temperature was raised from room temperature to 120 °C and stirred for 20 hours. After the reaction was complete, the precipitated solid was filtered, and the resulting solid was washed with toluene to obtain 13.0 g of intermediate 6 (yield 67%). The structure is 1 Identification was performed using 1H-NMR and LC-MS.

[0172] [ka]

[0173] Under a nitrogen atmosphere, 6.00 g of intermediate 6, 3.34 g of 3,7-diethyl-3,7-dimethylnonane-4,6-dione, 180 mL of 2-ethoxyethanol, and 1.47 g of sodium carbonate were added to a 300 mL round-bottom flask. The temperature was raised from room temperature to 120 °C and stirred for 3 hours. After the reaction was complete, the precipitated solid was filtered, and the resulting solid was washed with methanol to obtain 5.70 g (80% yield) of the target example compound 8. The structure is 1 Identification was performed using 1H-NMR and LC-MS.

[0174] Furthermore, when the synthesized example compound 8 was dissolved in toluene at a concentration of 1.0 × 10⁻⁵ M and its PL (photoluminescence) spectrum was measured, it showed red emission at an emission wavelength of 620 nm.

[0175] [Evaluation of horizontal orientation of luminescent materials used in Comparative Examples 1 to 7] Compounds A to G were synthesized as luminescent iridium complexes to be used in the device evaluation of Comparative Examples 1 to 7 using the same method as in Example 1. Molecular calculations were also performed on compounds A to G to determine their permanent dipole moments and horizontal orientation ratios. Table 1 shows the calculated permanent dipole moments and horizontal orientation ratios, the substituent species corresponding to R12 in general formulas (1) and (2), and whether the substituent satisfies the Parahammett constant (σp) of 0.5 or greater (indicated by ○) or not (indicated by ×).

[0176] [Evaluation of the horizontal orientation of the luminescent material used in Examples 2 to 15] For the device evaluation in Examples 2 to 15, compounds (1), (3), (6), (8), (12), (15), (16), (19), (20), (24), (31), (33), (34), and (45) were synthesized in the same manner as in Example 1 as luminescent iridium complexes. Furthermore, as with the compounds in Comparative Examples 1 to 7, molecular calculations were performed to determine the permanent dipole moment and horizontal orientation ratio. The results are shown in Table 1.

[0177] [Table 1]

[0178] [ka]

[0179] [Comparative Example 1] In Comparative Example 1, compound A was used as the guest compound in the host molecule of the light-emitting layer, and an organic light-emitting device was fabricated using the method described below, with the anode / hole injection layer / hole transport layer / electron blocking layer / light-emitting layer / hole blocking layer / electron transport layer / cathode sequentially provided on the substrate.

[0180] A transparent conductive support substrate (ITO substrate) was used, on which ITO was deposited as the anode to a thickness of 100 nm by sputtering on a glass substrate. On this ITO substrate, the following organic compound layer and electrode layer were added. -5 The film was continuously deposited by vacuum deposition using resistance heating in a Pa vacuum chamber. The electrode area at this time was 3 mm². 2 It was made to achieve this. Hole injection layer (10nm) HT16 Hole transport layer (30nm) Electron blocking (EB) layer (10 nm) Emitting layer (30nm) Host material: , Guest material: Compound A (4wt%) Hole blocking (HB) layer (20nm) Electron transport layer (20nm) Metal electrode layer 1 (1nm) Liq Metal electrode layer 2 (100nm) Al

[0181] Next, to prevent degradation of the organic light-emitting element due to moisture adsorption, a protective glass plate was placed over it in a dry air atmosphere and sealed with an acrylic resin adhesive. The organic light-emitting element was obtained in this manner. For the obtained organic light-emitting element, an IVL (current-voltage-luminance) measurement was performed with the ITO electrode as the anode and the Al electrode as the cathode. The organic light-emitting element measured 5 mA / cm². 2 Table 2 shows the external quantum efficiency (relative value) at this time. At this time, the organic light-emitting element using compound (12) in Example 6 had an efficiency of 5 mA / cm². 2 The external quantum efficiency at time was assumed to be 100%.

[0182] [Comparative Example 2 to Comparative Example 7] Organic light-emitting devices were fabricated in the same manner as in Comparative Example 1, except that the guest material was changed to compound B through compound G listed in Table 1. These were designated as Comparative Examples 2 through 7. IVL measurements were also performed on the obtained devices in the same manner as in Comparative Example 1. The results are shown in Table 2.

[0183] [Examples 2 to 15] In this embodiment, organic light-emitting devices were fabricated in the same manner as in Comparative Example 1, except that the guest material was changed to one of the compounds (1) to (45) listed in Table 1. These were designated as Comparative Examples 2 to 15. The obtained devices were also subjected to IVL measurements in the same manner as in Comparative Example 1. The results are shown in Table 2.

[0184] Examples 2 to 15 of the compounds according to the present invention, which contain a benzene ring, a naphthalene ring, or a benzoisoquinoline or naphthoisoquinoline skeleton having a C4-C10 heterocyclic group as a ligand and have a permanent dipole moment of 1.5 or less, show a 5 mA / cm² higher reading than compounds that do not contain a benzene ring and have a permanent dipole moment of 1.5 or more (Comparative Example 1), or compounds that correspond to general formula (1) or general formula (2) but have a permanent dipole moment of 1.5 or more (Comparative Examples 2 to 7). 2 The external quantum efficiency has improved significantly. Thus, the efficiency of organic light-emitting devices can be improved by using compounds with specific ligand structures that have a small permanent dipole moment.

[0185] Furthermore, compounds (1), (3), (6), (8), (15), (16), (20), (31), (33), and (45) according to the present invention, which have substituents on R12 with a Parahammett constant of 0.5 or more, exhibit improved efficiency compared to compounds (12), (19), (24), and (34) which do not have substituents on R12 with a Parahammett constant of 0.5 or more. In other words, it is suggested that the compounds according to the present invention have the effect of further improving efficiency by providing substituents on R12 with a Parahammett constant of 0.5 or more.

[0186] [Table 2]

[0187] As described above, it has been found that the iridium complex according to the present invention can improve the device lifespan of organic light-emitting devices. [Explanation of Symbols]

[0188] Single-layer insulating layer 2 reflective electrode 3. Insulating layer 4 Organic compound layer 5 Transparent electrode 6 Protective layer 7 Color Filters 10 subpixels 11 circuit boards 12 Insulating layer 13 gates 14 Gate insulating film 15 Semiconductor layer 16 Drain electrode 17 Source electrodes 18 Thin-film transistors 19 Insulating film 20 contact holes 21 Lower electrode 22 Organic compound layer 23 Upper electrode 24 First protective layer 25 Second protective layer 26 Organic light-emitting diodes 100 display device 1000 display devices 1001 Top cover 1002 Flexible Printed Circuits 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 Bending point 1400 Lighting device 1401 Housing 1402 Light source 1403 Circuit board 1404 Optical film 1405 Light diffusing part 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 iridium complex characterized by being represented by the following general formula [1] or [2] and having a permanent dipole moment of 1.5 or less. 【Chemistry 1】 【Chemistry 2】 In General Formulas [1] and [2], R ６ , ３ , ２ , ４ , １ , １ , ６ , ５ to R11, and R13 to R21 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, and a silyl group. R １２ is -CF ３ , -CN, -COF, -CF(CF ３ ) ２ , -OCF ３ , or -SiF ３ . CY １ is a group represented by any one of the following chemical formulas [3-1] to [3-3]. In Chemical Formulas [3-1] to [3-3], R ２２ to R ２７ are each independently selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted amino group, a cyano group, and a silyl group. In General Formula [3-1], X １ to X ４ are carbon atoms. In General Formula [3-3], X １ to X ６ are carbon atoms. In General Formula [3-2], X １ to X ２ , X ４ , and X ６ are carbon atoms, and X ３ and X ５ are nitrogen atoms, or X １ to X ６ are carbon atoms. 【Transformation 3】 【Chemistry 4】 【Transformation 5】

2. R in general formula [3-1] ２２ and R ２５ , R of general formula [3-2] ２２ and R ２７ , R in general formula [3-3] ２２ The iridium complex according to claim 1, characterized in that each of the atoms is independently selected from the group consisting of a hydrogen atom, a deuterium atom, and an alkyl group having 1 to 4 carbon atoms.

3. R in general formula [3-1] ２２ and R ２５ , R of general formula [3-2] ２２ and R ２７ , R in general formula [3-3] ２２ The iridium complex according to claim 1 or 2, characterized in that the atom is a hydrogen atom.

4. The aforementioned X １ ~X ６ The iridium complex according to any one of claims 1 to 3, characterized in that the carbon atom is a carbon atom.

5. The iridium complex according to any one of claims 1 to 4, characterized in that its permanent dipole moment is 1.0 or less.

6. CY １ The iridium complex according to any one of claims 1 to 5, characterized in that the ring is a benzene ring.

7. The aforementioned R １２ ga-CF ３ The iridium complex according to claim 2, characterized in that it is the iridium complex described in claim 2.

8. The aforementioned R １７ and R １９ The iridium complex according to claim 7, characterized in that it is an alkyl group having 1 to 4 carbon atoms.

9. The aforementioned R １７ and R １９ The iridium complex according to claim 8, characterized in that it is a methyl group.

10. The iridium complex according to any one of claims 1 to 9, characterized by being represented by the following structural formula. 【Transformation 6】

11. A luminescent ink composition comprising an iridium complex, a primary organic compound, and a solvent according to any one of claims 1 to 10.

12. An organic light-emitting element having a first electrode, a second electrode, and an organic compound layer disposed between the first electrode and the second electrode, wherein the organic compound layer has an iridium complex according to any one of claims 1 to 10.

13. The organic light-emitting element according to claim 12, characterized in that the organic compound layer has a light-emitting layer, and the light-emitting layer has the iridium complex.

14. The organic light-emitting element according to claim 13, wherein the light-emitting layer comprises the iridium complex and a first organic compound, and the first organic compound has a lower minimum excitation singlet energy greater than that of the iridium complex.

15. The organic light-emitting element according to claim 14, wherein the light-emitting layer has a second organic compound different from the first organic compound, and the second organic compound has a minimum excitation triplet energy that is lower than that of the first organic compound and higher than that of the iridium complex.

16. A display device having a plurality of pixels, wherein at least one of the plurality of pixels is an organic light-emitting element according to any one of claims 12 to 15 and a transistor connected to the organic light-emitting element.

17. It comprises an optical unit having multiple lenses, an image sensor that receives light that has passed through the optical unit, and a display unit that displays the image captured by the image sensor. The imaging apparatus is characterized in that the display unit has an organic light-emitting element as described in any one of claims 12 to 15.

18. An electronic device comprising: a display unit having an organic light-emitting element as described in any one of claims 12 to 15; a housing on which the display unit is provided; and a communication unit provided in the housing for communicating with the outside.

19. A lighting device comprising a light source having an organic light-emitting element as described in any one of claims 12 to 15, and a light-diffusing portion or optical film that transmits light emitted by the light source.

20. A mobile body characterized by comprising a lamp having an organic light-emitting element according to any one of claims 12 to 15, and a body on which the lamp is provided.

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