WO2023190219A1

WO2023190219A1 - Organic metal complex, and organic light-emitting element, display device, imaging device, electronic equipment, lighting device, and mobile object each containing organic metal complex

Info

Publication number: WO2023190219A1
Application number: PCT/JP2023/011951
Authority: WO
Inventors: 紅音上妻; 明坪山
Original assignee: キヤノン株式会社
Priority date: 2022-03-30
Filing date: 2023-03-24
Publication date: 2023-10-05

Abstract

Provided is an organic metal complex that is an iridium complex having ligands L1, L2 which are mutually different bidentate ligands. The LUMO energy level of Ir(L1)₃ constituted by only the ligand L1 is deeper than the LUMO energy level of Ir(L2)₃ constituted by only the ligand L2, and the HOMO energy level of Ir(L1)₃ is shallower than the HOMO energy level of Ir(L2)₃.

Description

Organometallic complexes, organic light-emitting devices containing the same, display devices, imaging devices, electronic devices, lighting devices, mobile objects

The present invention relates to an organometallic complex, an organic light-emitting element containing the organometallic complex in a light-emitting layer, and further to equipment and devices equipped with the organic light-emitting element.

An organic light emitting device is an electronic device that has a first electrode, a second electrode, and an organic compound layer disposed between these electrodes. By injecting electrons and holes into the organic compound layer from these pair of electrodes, excitons of the luminescent organic compound in the organic compound layer are generated, and when the excitons return to the ground state, the organic light emitting device emits light. Organic light emitting devices are also called organic electroluminescent devices or organic EL devices.

As luminescent organic compounds, phosphorescent materials that emit light from a triplet excited state exhibit high luminous efficiency in electrical exciton generation within organic light emitting devices, and 2-phenylpyridine is one of them. Ir(ppy) ₃ , which emits green light and has as a ligand, is known.

In recent years, with the spread of 4K and 8K televisions, it has become necessary to express a wider color gamut, but Ir(ppy) ₃ has a wide half-width emission spectrum and low color purity, so it is not possible to express a wide color gamut. It is difficult to express the area. Therefore, development of luminescent organic compounds whose emission spectrum has a narrow half-value width is underway.

In addition, in the production of organic light emitting devices, vacuum evaporation is used as a vapor deposition method, and spin coating, printing, and inkjet methods are used as wet methods to form a thin organic compound layer provided between a pair of electrodes. ing. Among them, the currently mainstream method is the vapor deposition method. In order to deposit the material, it is desirable to perform the deposition at an appropriate temperature that does not cause decomposition of the organic compound or deformation of the patterning mask. Therefore, efforts are being made to develop organic compounds that can sublimate at appropriate temperatures.

For luminescent materials, there is a need to develop organometallic complexes that exhibit ideal performance in both color purity, which shows an emission spectrum with a small half-width, and thermophysical properties, such as sublimation at a temperature suitable for vapor deposition. It is known that a complex having a dibenzofuran structure exhibits an emission spectrum with a small half-width.

Patent Document 1 describes that the sublimation temperature can be lowered by using an organometallic complex A represented by the following formula as an organometallic complex having a lower sublimation temperature than an organometallic complex composed only of a ligand having a dibenzofuran structure. It is possible to reduce this amount and use it in devices.

JP 2013-28604 specification

The present inventors synthesized an organometallic complex B composed only of a ligand L1-1 having a dibenzofuran structure represented by the following formula, and the organometallic complex A disclosed in Patent Document 1, The half width was compared. As a result, the half-value width of organometallic complex A was larger than that of organometallic complex B, and the color purity decreased. Thus, organometallic complex A, which has a lower sublimation temperature than organometallic complex B, has lower color purity than organometallic complex B, and it is difficult to achieve both high color purity and low sublimation temperature.

The present invention has been made in view of the above problems, and its purpose is to provide a luminescent organometallic complex that has a low sublimation temperature, is easy to apply to devices, and has high color purity. The present invention provides a device that uses an organometallic complex and has excellent light-emitting characteristics.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a luminescent organometallic complex whose emission spectrum has a narrow half-width and a low sublimation temperature.

The first aspect of the present invention is an iridium complex represented by the following general formula [1], in which the energy level of the LUMO of Ir(L1) ₃ is deeper than the energy level of the LUMO of Ir(L2) ₃ ; It is an organometallic complex characterized in that the energy level of the HOMO of (L1) ₃ is shallower than the energy level of the HOMO of Ir(L2) ₃ .
Ir(L1) _m (L2) _n [1]

In the above formula [1], L1 and L2 are different bidentate ligands, m and n are 1 or 2, and m+n is 3.

A second aspect of the present invention is 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, wherein the organic compound layer is , characterized by having the first organometallic complex of the present invention.

A third aspect of the present invention includes a plurality of pixels, and at least one of the plurality of pixels includes the second organic light-emitting element of the present invention and a transistor connected to the organic light-emitting element. This is a distinctive display device.

A fourth aspect of the present invention includes an optical section having a plurality of lenses, an image sensor that receives light that has passed through the optical section, and a display section that displays an image captured by the image sensor, and the display section that displays the image. Part is an imaging device characterized by having the second organic light emitting element of the present invention.

A fifth aspect of the present invention includes a display section having the second organic light emitting element of the present invention, a casing in which the display section is provided, and a communication section provided in the casing and communicating with the outside. This is an electronic device characterized by having the following features.

A sixth aspect of the present invention is a lighting device comprising a light source having the organic light emitting element according to the second aspect of the present invention, and a light diffusion section or an optical filter that transmits light emitted from the light source.

A seventh aspect of the present invention is a moving body characterized by having a lamp having the organic light emitting element according to the second aspect of the present invention, and a body provided with the lamp.

According to the present invention, an organic metal complex having a narrow half-value width of an emission spectrum and a low sublimation temperature is provided, and by having such an organic metal complex in an organic compound layer, an organic light emitting device with excellent light emission characteristics, and further , it is possible to provide equipment and devices equipped with the organic light emitting element.

FIG. 2 is an electron distribution diagram of LUMO of conventional organometallic complex A. FIG. 2 is a HOMO electron distribution diagram of a conventional organometallic complex A. FIG. 2 is a LUMO electron distribution diagram of the organometallic complex (1) of the present invention. FIG. 2 is a HOMO electron distribution diagram of the organometallic complex (1) of the present invention. FIG. 1 is a schematic cross-sectional view of an embodiment in which the organic light emitting device of the present invention is used as a pixel. 1 is a schematic cross-sectional view of an example of a configuration in which a transistor is connected to an organic light emitting device of the present invention. 1 is a schematic diagram of an embodiment of a display device of the present invention. 1 is a schematic diagram of an embodiment of an imaging device of the present invention. FIG. 1 is a schematic diagram of an embodiment of a mobile device of the present invention. FIG. 3 is a schematic diagram of another embodiment of the display device of the present invention. FIG. 1 is a schematic diagram illustrating an example of a foldable display device. FIG. 1 is a schematic diagram of an embodiment of a lighting device of the present invention. 1 is a schematic diagram showing an automobile which is an embodiment of a moving object of the present invention. 1 is a schematic diagram of an example of a wearable device including a display device of the present invention. FIG. 3 is a schematic diagram of another example of a wearable device including a display device of the present invention.

Hereinafter, embodiments of the present invention will be described. The present invention is not limited to the following description, and those skilled in the art will readily understand that the form and details thereof can be changed in various ways without departing from the spirit and scope of the present invention. That is, the present invention should not be construed as being limited by the following description.

[Organometallic complex]
As a result of study, the present inventors found that even if some ligands have a high sublimation temperature, they can be sublimed at a low temperature, and the emission spectrum has the same half-width as a ligand with high color purity. An organometallic complex represented by the following general formula [1] has been found.
Ir(L1)m(L2)n

In the above formula [1], L1 and L2 are arbitrary bidentate ligands different from each other, and are m and n1 or 2, and m+2=3.

The energy level of the LUMO of Ir(L1) ₃ is deeper than the energy level of the LUMO of Ir(L2) ₃ , and the energy level of the HOMO of Ir(L1) ₃ is the energy level of the HOMO of Ir(L2) ₃ . shallower than

In the above formula [1], L1 is preferably a ligand represented by the following general formula [2]. Moreover, it is preferable that L2 is a ligand represented by the following general formula [3]. The organometallic complex of the present invention preferably has L1 represented by formula [2] and L2 represented by formula [3].

In the above formula [2], X ₁ to X ₁₀ are carbon atoms or nitrogen atoms.

Further, in the above formula [3], X ₁₁ to X ₁₇ are carbon atoms or nitrogen atoms, and one or more of X ₁₅ to X ₁₇ is a nitrogen atom.

R ₁ to R ₅ are each independently a hydrogen atom, a deuterium atom, a halogen atom, an alkyl group, a cycloalkyl group, a heteroalkyl group, an arylalkyl group, an alkoxy group, an aryloxy group, an amino group, a silyl group, Alkenyl groups, cycloalkenyl groups, heteroalkenyl groups, alkynyl groups, aryl groups, heteroaryl groups, acyl groups, carboxylic acid residues, ester groups, nitrile groups, isonitrile groups, sulfanyl groups, sulfonic acid residues, phosphino groups, and these selected from the group consisting of a combination of R ₁ to R ₃ may further be boronyl groups. Moreover, in R ₁ and R ₂ and R ₄ and R ₅ , mutually adjacent substituents may be bonded to each other to form a ring structure.

Y is an oxygen atom, a sulfur atom, CR ₆ R ₇ , CR ₆ =CR ₇ , NR ₆ , BR ₆ , SiR ₆ R ₇ , C=O, C=NR ₆ , C=CR ₆ R ₆ , S=O, is a divalent bridging group selected from the group consisting of SO ₂ , CR ₆ R ₇ -CR ₆ R ₇ , PR ₆ , and P(=O)R ₆ , and R ₆ and R ₇ are each independently a straight selected from the group consisting of chain alkyl groups, branched alkyl groups, and aryl groups.

Specific examples of the organometallic complex of the present invention are listed below.

Next, the characteristics of the emission spectrum width in the organometallic complex of the present invention will be explained.

Figures 1 and 2 show electron distribution maps of LUMO (lowest unoccupied orbital) and HOMO (highest occupied orbital) of organometallic complex A calculated by density functional theory (B3PW91/LANL2DZ). FIG. 1 is an electron distribution diagram of LUMO, and FIG. 2 is an electron distribution diagram of HOMO.

The three-dimensional structures shown in FIGS. 1 and 2 were created using Gaussian09*Revision C., which is electronic structure calculation software. 01 was used to perform structural optimization calculations of the ground state. At that time, Density Functional Theory was adopted as the quantum chemical calculation method, and B3PW91 was used as the functional. The basis functions are Gaussian 09, Revision C. In 01, LANL2DZ was used.
Gaussian 09, Revision C. 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, RCami, 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, 2010.

As shown in Figures 1 and 2, the present inventor believes that the wide distribution of the electrons in the orbits involved in light emission between the two ligands is the reason why the half-width of the emission spectrum of organometallic complex A becomes large. I thought about it. Furthermore, it was considered that the electron distribution was influenced by the relationship between the LUMO and HOMO energy levels of the two ligands L1-1 and L2-1 constituting the organometallic complex A. Therefore, for Ir(L1-1) ₃ in which all three ligands are L1-1 and Ir(L2-1) ₃ in which all three ligands are L2-1, we calculated the LUMO and HOMO using density functional theory (B3PW91/LANL2DZ). The energy level of was calculated. Furthermore, organometallic complex A was synthesized, and the half width of the emission spectrum was measured and the values are shown in Table 1 below. Note that the HOMO energy level is also called the "HOMO level" or "HOMO", and the LUMO energy level is also called the "LUMO level" or "LUMO".

The half-width of the emission spectrum of the homoleptic complex in which all the ligands are L1-1 is 34 nm, while the half-width of organometallic complex A is 52 nm, indicating that the color purity has deteriorated. . Furthermore, when comparing the LUMO and HOMO energy levels of the ligands L1-1 and L2-1 constituting organometallic complex A, Ir(L2-1) ₃ has a deeper LUMO level and a lower HOMO level. Regarding the position, Ir(L2-1) ₃ is shallower. The present inventors considered that the reason why the electron distribution of LUMO and HOMO of organometallic complex A is spread over two ligands is due to such a magnitude relationship of energy levels.

Therefore, an organometallic complex (1) represented by the following formula was designed. Regarding the ligands L1-2 and L2-2 that constitute this, the LUMO and HOMO energy levels of Ir(L1-2) ₃ and Ir(L2-2) ₃ were calculated using density functional theory (B3PW91/LANL2DZ). Calculated. Furthermore, the organometallic complex (1) which is Ir(L1-2)(L2-2) ₂ was synthesized, and the measured half-width of the emission spectrum is shown in Table 2, and the electron distribution diagram of LUMO is shown in Figure 3. Figure 4 shows the electron distribution diagram of HOMO.

Looking at the relationship between the energy levels of LUMO and HOMO, Ir(L1-2) ₃ has a deeper LUMO level, and Ir(L1-2) ₃ has a shallower HOMO level. As a result, it can be seen that the electron distribution diagram of LUMO and HOMO of organometallic complex (1) also shows that electrons are distributed biased towards the ligand L1-2. Furthermore, the half width was also significantly narrower than that of the organometallic complex (A). In this way, in the structure of general formula [1], "the LUMO level of Ir(L1) ₃ _is The HOMO level of Ir(L1) ₃ is shallower than the HOMO level of Ir(L2) ₃ . The chemical structure that satisfies this condition is preferably an organic metal having either a structure in which L1 is represented by the general formula [2] or a structure in which L2 is represented by the general formula [3], more preferably both. It is a complex.

Further, in the general formula [2], it is preferable that X ₁ to X ₁₀ are carbon atoms, since the sublimation temperature of the organometallic complex is low. Furthermore, R ₁ other than a hydrogen atom is substituted at the 4-position of the pyridine ring, which is preferable in that the roll-off phenomenon is reduced.

Further, in _the general formula [3 _] , X ₁₅ is a nitrogen atom, X ₁₁ to X ₁₄ and X ₁₆ to Either one is preferable in that the sublimation temperature of the organometallic complex is low. Among the organometallic complexes exemplified above, (1), (17), (27), (29), and (36) are more preferred.

Note that the sublimation temperature of the organometallic complex is evaluated by the 5% weight loss temperature (T5) in the thermogravimetric analysis (TG) curve. It is preferable that T5 of Ir(L1) ₃ and Ir(L2) ₃ is greater than or equal to T5 of the organometallic complex represented by the above formula [1].

[Organic compound layer]
Next, an organic compound layer included in an organic light emitting device according to an embodiment of the present invention will be described. The organic light emitting device according to this embodiment includes 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 according to 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.

Here, when the organic compound layer is a laminate consisting of multiple layers, the organic compound layer includes, 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, and an electron injection layer. It may have layers or the like. Further, the light emitting layer may be a single layer or a laminate consisting of a plurality of layers. The hole transport layer and the electron transport layer are also referred to as charge transport layers.

In the organic light emitting device according to the present embodiment, at least one of the organic compound layers contains the organometallic complex according to the present embodiment. Specifically, the organometallic complex according to the present embodiment may be added to any of the above-mentioned hole injection layer, hole transport layer, electron blocking layer, light emitting layer, hole/exciton blocking layer, electron transport layer, electron injection layer, etc. Preferably, it is 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. That is, it can be said that the light-emitting layer is in contact with the first charge transport layer and the second charge transport layer.

In the organic light emitting device according to this embodiment, when the organometallic complex according to this embodiment is included in the light emitting layer, the light emitting layer may be a layer consisting only of the organometallic complex according to this embodiment, or may be a layer consisting only of the organometallic complex according to this embodiment. It may contain a first organic compound different from the organometallic complex. Furthermore, the layer may include the organometallic complex and a second organic compound different from the first organic compound. The first organic compound may have a lowest excited triplet energy that is higher than the lowest excited triplet energy of the organometallic complex according to this embodiment. The second organic compound may have a lowest excited triplet energy that is greater than or equal to the lowest excited triplet energy of the organometallic complex according to this embodiment and less than or equal to the lowest excited triplet energy of the first organic compound. Here, when the light-emitting layer is a layer having a first organic compound and a second organic compound, the first organic compound may be a host of the light-emitting layer. Further, the second organic compound may be an assist material. The organometallic complex according to this embodiment may be a guest or a dopant.

Here, the host is a compound having the largest mass ratio among the compounds constituting the light emitting layer. Moreover, the guest or dopant is a compound whose mass ratio is smaller than that of the host among the compounds constituting the light emitting layer, and is a compound responsible for main light emission. The assist material is a compound that has a smaller mass ratio than the host among the compounds constituting the light emitting layer and assists the guest in emitting light. Note that the assist material is also called a second host.

Here, when the organometallic complex according to the present 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 based on the entire light emitting layer, and 0.1% by mass or less. It is more preferable that the amount is 10.0% by mass or more and 10.0% by mass or less. The entire light-emitting layer refers to the total mass of compounds constituting the light-emitting layer.

Furthermore, the lowest excited triplet energy of the first charge transport layer is preferably higher than the lowest excited triplet energy of the first organic compound. Further, the lowest excited triplet energy of the second charge transport layer is preferably higher 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 material of the layer. When the charge transport layer is composed of a plurality of materials, it may be the lowest excited triplet energy of a compound having a large mass ratio.

The present inventors conducted various studies and found that when the organometallic complex according to the present embodiment is used as a guest in the light emitting layer, it exhibits high efficiency and high brightness light output and has good roll-off property. Ta. This light-emitting layer may be a single layer or a multi-layer, and by including a light-emitting material having another luminescent color, it is possible to mix the luminescent color with the luminescent color of this embodiment. Multilayer means a state in which a plurality of light emitting layers are stacked. In this case, the emission color of the organic light emitting element is not limited to the same hue as the emission color of the single layer. More specifically, it may be white or an intermediate color. In the case of white color, the white color may be obtained by emitting red, blue, and green light from each light emitting layer, or may be obtained by combining complementary emitting colors.

The organometallic complex according to this embodiment can also be used as a constituent material of an organic compound layer other than the light emitting layer that constitutes the organic light emitting device according to this embodiment. Specifically, it may be used as a constituent material of an electron transport layer, an electron injection layer, a hole transport layer, a hole injection layer, a hole blocking layer, etc.

When manufacturing the organic light-emitting device according to this embodiment, conventionally known low-molecular and high-molecular hole-injecting compounds or hole-transporting compounds, host compounds, light-emitting compounds, and electron-injecting compounds may be used as necessary. A compound or an electron transporting compound can be used together. Examples of these compounds are listed below.

As the hole injection and transport material, a material with high hole mobility is preferable so that holes can be easily injected from the anode and the injected holes can be transported to the light emitting layer. Further, in order to reduce deterioration of film quality such as crystallization in an organic light emitting device, a material having a high glass transition temperature is preferable. Examples of low-molecular and high-molecular materials having hole injection and transport properties include triarylamine derivatives, arylcarbazole derivatives, phenylenediamine derivatives, triazole derivatives, oxadiazole derivatives, imidazole derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, and Examples include conductive polymers such as arylamine derivatives, polyvinylcarbazole derivatives, polythiophene derivatives, PEDOT-PSS, and copolymers or mixtures thereof. Furthermore, the hole injection and transport material described above is also suitably used for an electron blocking layer.

Specific examples of compounds used as the hole injection transport material are shown below, but the invention is of course not limited to these.

In addition to the organometallic complex of this embodiment, other light-emitting materials can also be added as the light-emitting materials mainly related to the light-emitting function. 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, tris(8-quinolinolate) aluminum organoaluminum complexes such as tris(2-phenylpyridinato)iridium, iridium complexes such as platinum complexes, rhenium complexes, copper complexes, europium complexes, ruthenium complexes, and poly(phenylenevinylene) derivatives, poly(fluorene) derivatives, Examples include polymer derivatives such as poly(phenylene) derivatives.

Specific examples of compounds used as luminescent materials are shown below, but of course the compounds are not limited to these.

Examples of the light-emitting layer host or light-emission assisting material contained in the light-emitting layer include aromatic hydrocarbon compounds or their derivatives, as well as organic aluminum such as carbazole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, triazine derivatives, and tris(8-quinolinolate) aluminum. Examples include polymers such as complexes, organic beryllium complexes, polyphenylene derivatives, polyphenylene vinylene derivatives, polyfluorene derivatives, and polyvinylcarbazole derivatives, and copolymers or mixtures thereof.

Specific examples of compounds used as the light-emitting layer host or light-emission assist material contained in the light-emitting layer are shown below, but of course the compounds are not limited to these.

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, fused ring compounds (e.g. fluorene derivatives, naphthalene derivatives, chrysene derivatives, anthracene derivatives, etc.). Furthermore, the above-mentioned electron-transporting materials are also suitably used for hole-blocking layers.

Specific examples of compounds used as electron transporting materials are shown below, but of course the compounds are not limited to these.

The electron-injecting material can be arbitrarily selected from materials that can easily inject electrons from the cathode, and is selected in consideration of the balance with the hole-injecting property. The organic compound also includes an n-type dopant and a reducing dopant. 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.

[Organic light emitting device]
The organic light emitting device according to this embodiment 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 flattening layer may be provided between the color filter and the protective layer. The flattening layer can 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. The constituent members of the organic light emitting device will be explained below.

<substrate>
Examples of the substrate include quartz, glass, silicon wafer, resin, metal, and the like. Furthermore, switching elements such as transistors and wiring may be provided on the substrate, and an insulating layer may be provided thereon. The insulating layer may be made of any material as long as it can form a contact hole to ensure conduction between the anode and the wiring, and can ensure insulation from unconnected wiring. For example, resin such as polyimide, silicon oxide, silicon nitride, etc. can be used.

<electrode>
A pair of electrodes can be used as the electrodes. 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 the 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.

It is preferable that the material for the anode has a work function as large as possible. For example, metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, tungsten, mixtures containing these metals, alloys of combinations of these metals, tin oxide, zinc oxide, indium oxide, and indium oxide. Metal oxides such as tin (ITO) and indium zinc oxide can be used. Conductive polymers such as polyaniline, polypyrrole, and polythiophene can also be used.

One type of these electrode materials may be used alone, or two or more types may be used in combination. Further, the anode may be composed of a single layer or a plurality of layers.

When used as a reflective electrode, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, an alloy thereof, or a stacked layer thereof can be used. When used as a transparent electrode, transparent conductive layers of oxides such as indium tin oxide (ITO) and indium zinc oxide can be used, but are not limited thereto. Photolithography technology can be used to form the electrodes.

On the other hand, the material for the cathode should preferably have a small work function. Examples include alkali metals such as lithium, alkaline earth metals such as calcium, single metals such as aluminum, titanium, manganese, silver, lead, and chromium, or mixtures containing these metals. Alternatively, an alloy that is a combination of these metals can also be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, zinc-silver, etc. can be used. Metal oxides such as indium tin oxide (ITO) can also be used. These electrode materials may be used alone or in combination of two or more. Further, the cathode may have a single layer structure or a multilayer structure. Among these, it is preferable to use silver, and in order to suppress agglomeration of silver, it is more preferable to use a silver alloy. The ratio of the alloy does not matter as long as the aggregation of silver can be suppressed. For example, the ratio may be 1:1.

The cathode may be a top emission element using an oxide conductive layer such as indium tin oxide (ITO), or may be 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 it is more preferable to use a direct current or an alternating current sputtering method because the coverage of the film is good and the resistance can be easily lowered.

<Protective layer>
A protective layer may be provided on the second electrode. For example, by adhering glass provided with a moisture absorbent onto the second electrode, it is possible to reduce the intrusion of water and the like into the organic compound layer, thereby reducing the occurrence of display defects. In another embodiment, a passivation film made of silicon nitride or the like may be provided on the second electrode to reduce the infiltration of water or the like into the organic compound layer. For example, after forming the second electrode, the second electrode may be transferred to another chamber without breaking the vacuum, and a silicon nitride film having a thickness of 2 μm may be formed using a CVD method to form a protective layer. A protective layer may be provided using an atomic deposition method (ALD method) after film formation using a CVD method.

<Color filter>
A color filter may be provided on the protective layer. For example, a color filter that takes into account the size of the organic light emitting element may be provided on another substrate and bonded to the substrate on which the organic light emitting element is provided, or a color filter may be formed using photolithography technology on the protective layer shown above. , the color filter may be patterned. The color filter may be made of polymer.

<Planarization layer>
A flattening layer may be provided between the color filter and the protective layer. The planarization layer may be composed of an organic compound, and may be a low molecule or a polymer, but preferably a polymer. The planarization layer may be provided above and below the color filter, and its constituent materials may be the same or different. Specific examples include polyvinyl carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, urea resin, and the like.

<Counter board>
A 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 above-described substrate. The constituent material of the counter substrate may be the same as that of the above-described substrate. The counter substrate may be the second substrate when the above-mentioned substrate is the first substrate.

<Formation of organic compound layer>
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 this embodiment are formed by the method shown below. It is formed.

The method for forming the organic compound layer constituting the organic light emitting device according to this embodiment is not particularly limited, but a dry process or a wet process can be used. As an example of the dry process, dry processes such as vacuum evaporation, ionization evaporation, sputtering, and plasma can be used. Examples of wet processes include dissolving in a suitable solvent and applying known coating methods (for example, spin coating, casting, micro gravure coating, gravure coating, bar coating, roll coating, wire bar coating, dipping). coating method, spray coating method, screen printing method, flexo printing method, offset printing method, inkjet printing method, capillary coating method, nozzle coating method, etc.) can be used. Among these, vacuum evaporation, ionization evaporation, inkjet printing, nozzle coating, and the like are suitable for manufacturing large-area organic light-emitting devices.

The thickness of each layer in the organic light emitting device is usually 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 in order to obtain effective light emitting characteristics.

[Pixel circuit]
The organic light emitting device according to this embodiment may be used as a light emitting device by connecting a pixel circuit to the organic light emitting device. Such a pixel circuit may be of an active matrix type in which light emission is controlled independently of the first organic light emitting element and the second organic light emitting element. Active matrix type circuits may be voltage programming or current programming. The drive circuit has a pixel circuit for each pixel. The pixel circuit includes an organic light-emitting element, a transistor that controls the luminance of the organic light-emitting element, a transistor that controls the timing of light emission, a capacitor that maintains the gate voltage of the transistor that controls the luminance, and a capacitor that is connected to GND without going through the organic light-emitting element. It may also include a transistor for connection.

The light emitting device has a display area and a peripheral area arranged around the display area. The display area has a pixel circuit, and the peripheral area has a display control circuit. The mobility of the transistors forming the pixel circuit may be lower than the mobility of the transistors forming the display control circuit.

The slope of the current-voltage characteristics of the transistors forming the pixel circuit may be smaller than the slope of the current-voltage characteristics of the transistors forming the display control circuit. The slope of the current-voltage characteristic can be measured by the so-called Vg-Ig characteristic.

The transistors constituting the pixel circuit are transistors connected to an organic light emitting element, such as a first organic light emitting element.

[Pixel]
A light emitting device including an organic light emitting element according to this embodiment may have a plurality of pixels. Each pixel has subpixels that emit different colors. For example, each subpixel may have an RGB emission color.

A region of a pixel, also called a pixel aperture, emits light. The pixel aperture may be less than or equal to 15 μm, and may be greater than or equal to 5 μm. More specifically, it may be 11 μm, 9.5 μm, 7.4 μm, 6.4 μm, etc. Further, the distance between subpixels may be 10 μm or less, and specifically, it may be 8 μm, 7.4 μm, or 6.4 μm.

Pixels can take a known arrangement form in a plan view. For example, it may be a stripe arrangement, a delta arrangement, a pentile arrangement, or a Bayer arrangement. The shape of the subpixel in a plan view may take any known shape. For example, a rectangle, a square such as a diamond, a hexagon, etc. Of course, it is not an exact figure, but if it has a shape close to a rectangle, it is included in the rectangle. The shape of the subpixel and the pixel arrangement can be used in combination.

[Applications of organic light emitting devices]
The organic light emitting device according to this embodiment can be used as a component of a display device or a lighting device. Other uses include exposure light sources for electrophotographic image forming apparatuses, backlights for liquid crystal display devices, and light emitting devices having a white light source with a color filter.

The display device has an image input section that inputs image information from an area CCD, linear CCD, memory card, etc., has an information processing section that processes the input information, and displays the input image on the display section. An image information processing device may also be used.

Furthermore, the display section of the imaging device or the inkjet printer may have a touch panel function. The driving method for this touch panel function is not particularly limited, and may be an infrared method, a capacitance method, a resistive film method, or an electromagnetic induction method. Further, the display device may be used as a display section of a multi-function printer.

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

FIG. 5A is a schematic cross-sectional view of an example embodiment in which the organic light emitting device 8 according to this embodiment is used as a pixel. The pixel has sub-pixels 10. The subpixels are divided into 10R, 10G, and 10B depending on their light emission. The emitted light color 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 using a color filter or the like. Each subpixel includes a reflective electrode 2 as a first electrode on an interlayer insulating layer 1, an insulating layer 3 covering an end of the reflective electrode 2, an organic compound layer 4 covering the reflective electrode 2 and the insulating layer 3, and a transparent electrode. 5, a protective layer 6, and a color filter 7.

The interlayer insulating layer 1 may have a transistor or a capacitive element arranged thereunder or inside it. The transistor and the reflective electrode 2 may be electrically connected via a contact hole (not shown) or the like. The insulating layer 3 is also called a bank or a pixel isolation film. It covers the end of the reflective electrode 2 and is arranged to surround the reflective electrode 2. A portion of the reflective electrode 2 where the insulating layer 3 is not provided contacts the organic compound layer 4 and becomes a light emitting region. The organic compound layer 4 has a light-emitting layer and, if necessary, a hole injection layer, a hole transport layer, an electron transport layer, and the like. The transparent electrode 5 may be a semi-transparent electrode. The protective layer 6 reduces the penetration of moisture into the organic compound layer 4 . Although the protective layer 6 is illustrated as having a single layer, it may have multiple layers. Each layer may include an inorganic compound layer and an organic compound layer. The color filter 7 is divided into 7R, 7G, and 7B depending on its color. The color filter 7 may be formed on a planarization film (not shown). Further, a resin protective layer (not shown) may be provided on the color filter 7. Further, the color filter 7 may be formed on the protective layer 6. Alternatively, it may be provided on a counter substrate such as a glass substrate and then bonded together.

FIG. 5B is a schematic cross-sectional view of an example of a configuration in which a transistor is connected to the organic light-emitting element according to this embodiment. A transistor is one of active elements (switching elements). The transistor may be a thin film transistor (TFT).

In FIG. 5B, a substrate 11 made of glass, silicon, etc. and an insulating layer 12 are provided on top of the substrate 11. A transistor 18 is arranged on the insulating layer 12, and a gate electrode 13, a gate insulating film 14, and a semiconductor layer 15 of the transistor 18 are arranged. The transistor 18 also includes a semiconductor layer 15, a drain electrode 16, and a source electrode 17. An insulating film 19 is provided above the transistor 18 . An anode 21 and a source electrode 17 forming an organic light emitting element 26 are connected through a contact hole 20 provided in an insulating film 19 .

Note that the method of electrical connection between the electrodes (anode 21, cathode 23) included in the organic light emitting element 26 and the electrodes (source electrode 17, drain electrode 16) included in the transistor 18 is limited to the mode shown in FIG. 5B. It's not a thing. That is, it is sufficient that either the anode 21 or the cathode 23 is electrically connected to either the source electrode 17 or the drain electrode 16 of the transistor 18.

Although the organic compound layer 22 is illustrated as one layer in FIG. 5B, the organic compound layer 22 may be a plurality of layers. 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 26. Further, although the transistor 18 is used as a switching element, other switching elements may be used instead. Further, the transistor 18 is not limited to a transistor using a single crystal silicon wafer, but may be a thin film transistor having an active layer on an insulating surface of a substrate. Examples of the active layer 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.

The transistor 18 in FIG. 5B may be formed within a substrate such as a Si substrate. Here, "formed in a substrate" means that the transistor is fabricated by processing the substrate itself, such as a Si substrate. In other words, having a transistor within the substrate can also be considered to mean that the substrate and the transistor are integrally formed.

The luminance of the organic light-emitting device according to this embodiment is controlled by a transistor, which is an example of a switching element, and by providing the organic light-emitting devices in multiple planes, images can be displayed with the luminance of each device. Note that the switching element according to this embodiment is not limited to a thin film transistor, but may be a transistor formed of 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 a transistor is provided within the substrate or a thin film transistor is used is selected depending on the size of the display section. For example, if the size is about 0.5 inch, it is preferable to provide the organic light emitting element on the Si substrate.

FIG. 6 is a schematic diagram showing the configuration of the display device according to this embodiment. The display device 1000 includes 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. Flexible printed circuits (FPC) 1002 and 1004 are connected to the touch panel 1003 and the display panel 1005. A transistor is printed on the circuit board 1007. The battery 1008 may not be provided unless the display device is a portable device, or may be provided at a different location even if the display device is a portable device.

The display device according to this embodiment may include color filters having red, green, and blue. In the color filter, the red, green, and blue colors may be arranged in a delta arrangement, a stripe arrangement, or a mosaic arrangement.

The display device according to this embodiment may be used as a display section of a mobile terminal. In that case, it may have both a display function and an operation function. Examples of mobile terminals include mobile phones such as smartphones, tablets, head-mounted displays, and the like.

The display device according to this embodiment may be used as a display section of an imaging device that has an optical section that has a plurality of lenses and an image sensor that receives light that has passed through the optical section. The imaging device may include a display unit that displays information acquired by the imaging device. Furthermore, the display section may be a display section exposed to the outside of the imaging device, or a display section disposed within the viewfinder. The imaging device may be a digital camera or a digital video camera. The imaging device can also be called a photoelectric conversion device.

FIG. 7A is a schematic diagram showing an example of an imaging device according to this embodiment. The imaging device 1100 includes a viewfinder 1101, a rear display 1102, an operation section 1103, and a housing 1104. The viewfinder 1101 has 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, and the like. The environmental information may include the intensity of external light, the direction of external light, the moving speed of the subject, the possibility that the subject will be blocked by a shielding object, and the like.

Since the optimal timing for imaging is only a short time, it is better to display information as early as possible. Therefore, it is preferable to use a display device using the organic light emitting device of this embodiment. This is because organic light emitting devices have a fast response speed. Display devices using organic light-emitting elements can be used more favorably than these devices and liquid crystal display devices, which require high display speed.

The imaging device 1100 has an optical section (not shown). The optical section has a plurality of lenses and forms an image on an image sensor housed in the housing 1104. The focus of the plural lenses can be adjusted by adjusting their relative positions. This operation can also be performed automatically.

FIG. 7B is a schematic diagram showing an example of an electronic device according to this embodiment. Electronic device 1200 includes a display section 1201, an operation section 1202, and a housing 1203. The housing 1203 may include a circuit, a printed circuit board including 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 and performs unlocking and the like. An electronic device having a communication section 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 section. Examples of electronic devices include smartphones, notebook computers, and the like.

8A and 8B are schematic diagrams showing other examples of the display device according to this embodiment. FIG. 8A shows a display device such as a television monitor or a PC monitor. The display device 1300 has a frame 1301 and a display portion 1302. The display portion 1302 uses the light emitting device according to this embodiment. The display device in FIG. 8A has a frame 1301 and a base 1303 that supports a display portion 1302. The base 1303 is not limited to the form shown in FIG. 8A. Further, the lower side of the picture frame 1301 may also serve as a base. Further, the frame 1301 and the display portion 1302 may be curved. The radius of curvature may be greater than or equal to 5000 mm and less than or equal to 6000 mm.

FIG. 8B is a schematic diagram showing another example of the display device according to this embodiment. The display device 1310 in FIG. 8B is configured to be foldable, and is a so-called foldable display device. The display device 1310 includes a first display section 1311, a second display section 1312, a housing 1313, and a bending point 1314. The first display section 1311 and the second display section 1312 have display devices according to this embodiment. The first display section 1311 and the second display section 1312 may be one seamless display device. The first display section 1311 and the second display section 1312 can be separated at a bending point. The first display section 1311 and the second display section 1312 may each display different images, or the first display section 1311 and the second display section 1312 may display one image.

FIG. 9A is a schematic diagram showing an example of the lighting device according to the present embodiment. The lighting device 1400 may include a housing 1401, a light source 1402, a circuit board 1403, an optical filter 1404, and a light diffusing section 1405. The light source includes the organic light emitting device according to this embodiment. The optical filter 1404 may be a filter that improves the color rendering properties of the light source. The light diffusing unit 1405 can effectively diffuse the light from a light source, such as when lighting up, and can deliver the light to a wide range. The optical filter 1404 and the light diffusing section 1405 may be provided on the light emission side of the illumination. If necessary, a cover may be provided on the outermost side.

The lighting device 1400 is, for example, a device that illuminates a room. The lighting device 1400 may emit white, neutral white, or any other color from blue to red. It may have a dimming circuit for dimming them. The lighting device 1400 may include the organic light emitting device of the present invention and a power supply circuit connected thereto. The power supply circuit is a circuit that converts alternating current voltage to direct current voltage. Further, white has a color temperature of 4200K, and neutral white has a color temperature of 5000K. The lighting device 1400 may have a color filter.

Furthermore, the lighting device according to this embodiment may include a heat radiating section. The heat radiation part radiates heat within the device to the outside of the device, and may be made of metal with high specific heat, liquid silicone, or the like.

FIG. 9B is a schematic diagram of an automobile that is an example of a moving object according to the present embodiment. The automobile has a tail lamp, which is an example of a lamp. The automobile 1500 may have a tail lamp 1501, and the tail lamp may be turned on when a brake operation or the like is performed. The tail lamp 1501 includes an organic light emitting element according to this embodiment. The tail lamp may include a protection member that protects 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. Furandicarboxylic acid derivatives, acrylonitrile derivatives, etc. may be mixed with polycarbonate.

The automobile 1500 may have a vehicle body 1503 and a window 1502 attached to it. The window may be a transparent display as long as it is not a window for checking the front and rear of the vehicle. The transparent display includes an organic light emitting device according to this embodiment. In this case, constituent materials such as electrodes included in the organic light emitting element are made of transparent members.

The moving object according to this embodiment may be a ship, an aircraft, a drone, etc. The moving body may include a body and a lamp provided on the body. The light may emit light to indicate the position of the aircraft. The lamp includes the organic light emitting device according to this embodiment.

Application examples of the display devices of each of the above embodiments will be described with reference to FIGS. 10A and 10B. The display device can be applied to systems that can be worn as wearable devices, such as smart glasses, HMDs, and smart contacts. An imaging display device used in such an application example includes an imaging device capable of photoelectrically converting visible light and a display device capable of emitting visible light.

FIG. 10A illustrates eyeglasses 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 the lens 1601 of the glasses 1600. Further, the display device of each embodiment described above is provided on the back side of the lens 1601. Glasses 1600 further include a control device 1603. The control device 1603 functions as a power source that supplies power to the imaging device 1602 and the display device according to each embodiment. Further, the control device 1603 controls the operations of the imaging device 1602 and the display device. An optical system for condensing light onto an imaging device 1602 is formed in the lens 1601.

FIG. 10B illustrates glasses 1610 (smart glasses) according to another application example. The glasses 1610 include a control device 1612, and the control device 1612 is equipped with an imaging device corresponding to the imaging device 1602 and a display device. The lens 1611 is formed with an optical system for projecting light emitted from the imaging device in the control device 1612 and the display device, and an image is projected onto the lens 1611. The control device 1612 functions as a power source that supplies power to the imaging device and the display device, and controls the operation of the imaging device and the display device. The control device 1612 may include a line-of-sight detection unit that detects the wearer's line of sight. Infrared rays may be used to detect line of sight. The infrared light emitting unit emits infrared light to the eyeballs of the user who is gazing at the displayed image. A captured image of the eyeball is obtained by detecting the reflected light of the emitted infrared light from the eyeball by an imaging section having a light receiving element. By having a reduction means for reducing light emitted from the infrared light emitting section to the display section in plan view, deterioration in image quality is reduced.

The user's line of sight with respect to the displayed image is detected from the captured image of the eyeball obtained by infrared light imaging. Any known method can be applied to line of sight detection using a captured image of the eyeball. As an example, a line of sight detection method based on a Purkinje image by reflection of irradiated light on the cornea can be used.

More specifically, line of sight detection processing is performed based on the pupillary corneal reflex method. Using the pupillary corneal reflex method, the user's line of sight is detected by calculating a line of sight vector representing the direction (rotation angle) of the eyeball based on the pupil image and Purkinje image included in the captured image of the eyeball. Ru.

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

Specifically, in the display device, a first viewing area that the user gazes at and a second viewing area other than the first viewing area are determined based on the line-of-sight information. The first viewing area and the second viewing area may be determined by the control device of the display device, or may be determined by an external control device and may be received. In the display area of the display device, the display resolution of the first viewing area may be controlled to be higher than the display resolution of the second viewing area. That is, the resolution of the second viewing area may be lower than that of the first viewing area.

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

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

When display control is performed based on visual detection, it can be preferably applied to smart glasses that further include an imaging device that captures images of the outside. Smart glasses can display captured external information in real time.

As explained above, by using the device using the organic light emitting element according to this embodiment, stable display with good image quality can be achieved even for long periods of time. Further, by using a device using the organic light emitting element according to this embodiment, it is possible to achieve both good outdoor visibility and power-saving display due to high efficiency and high brightness light output.

[Included configurations]
The disclosure of this embodiment includes the following configurations.

(Configuration 1)
An iridium complex represented by the following general formula [1], the energy level of the LUMO of Ir(L1) ₃ is deeper than the energy level of the LUMO of Ir(L2) ₃ , and the HOMO of Ir(L1) ₃ An organometallic complex characterized in that its energy level is shallower than the HOMO energy level of Ir(L2) ₃ .
Ir(L1) _m (L2) _n [1]

In the above formula [1], L1 and L2 are different bidentate ligands, m and n are 1 or 2, and m+n=3.

(Configuration 2)
The 5% weight loss temperature (T5) of Ir(L1) ₃ or Ir(L2) ₃ in the thermogravimetric analysis (TG) curve is equal to or higher than T5 of the iridium complex represented by the general formula [1]. The organometallic complex according to configuration 1.

(Configuration 3)
The organometallic complex according to Structure 1 or 2, wherein L1 is represented by the following general formula [2].

In the above formula [2], X ₁ to X ₁₀ are carbon atoms or nitrogen atoms.

R ₁ to R ₃ are each independently a hydrogen atom, a deuterium atom, a halogen atom, an alkyl group, a cycloalkyl group, a heteroalkyl group, an arylalkyl group, an alkoxy group, an aryloxy group, an amino group, a silyl group, Alkenyl group, cycloalkenyl group, heteroalkenyl group, alkynyl group, aryl group, heteroaryl group, acyl group, carboxylic acid residue, ester group, nitrile group, isonitrile group, sulfanyl group, sulfonic acid residue, phosphino group, boronyl and combinations thereof. Furthermore, R ₁ and R ₂ may be bonded to each other to form a ring structure.

Y is an oxygen atom, a sulfur atom, CR ₆ R ₇ , CR ₆ =CR ₇ , NR ₆ , BR ₆ , SiR ₆ R ₇ , C=O, C=NR ₆ , C=CR ₆ R ₆ , S=O, is a divalent crosslinking group selected from the group consisting of SO ₂ , CR ₆ R ₇ -CR ₆ R ₇ , PR ₆ and P(=O)R ₆ , and R ₆ and R7 are each independently a linear selected from the group consisting of alkyl groups, branched alkyl groups, and aryl groups.

(Configuration 4)
The organometallic complex according to configuration 3, wherein in the formula [2], X ₁ to X ₁₀ are carbon atoms.

(Configuration 5)
The organometallic complex according to configuration 4, wherein in the formula [2], R ₁ other than a hydrogen atom is substituted at the 4-position of the pyridine ring.

(Configuration 6)
6. The organometallic complex according to any one of Structures 1 to 5, wherein L2 is represented by the following general formula [3].

In the above formula [3], X ₁₁ to X ₁₇ are carbon atoms or nitrogen atoms, and any one or more of X ₁₅ to X ₁₇ is a nitrogen atom.

R ₄ and R ₅ each independently represent a hydrogen atom, a deuterium atom, a halogen atom, an alkyl group, a cycloalkyl group, a heteroalkyl group, an arylalkyl group, an alkoxy group, an aryloxy group, an amino group, a silyl group, From alkenyl groups, cycloalkenyl groups, heteroalkenyl groups, alkynyl groups, aryl groups, heteroaryl groups, acyl groups, carboxylic acid residues, ester groups, nitrile groups, isonitrile groups, sulfanyl groups, sulfonic acid residues, and combinations thereof. Adjacent substituents may be bonded to each other to form a ring structure.

(Configuration 7)
The organometallic complex according to configuration 6, wherein in the formula [3], X ₁₅ is a nitrogen atom, and X ₁₁ to X ₁₄ and X ₁₆ to X ₁₇ are carbon atoms.

(Configuration 8)
The organometallic complex according to configuration 6 or 7, wherein in the formula [3], R ₅ is a hydrogen atom, an alkyl group, or a cycloalkyl group.

(Configuration 9)
The organometallic complex according to configuration 8, wherein the organometallic complex is one of the following formulas [4] to [8].

(Configuration 10)
An organic light emitting device comprising a first electrode, a second electrode, and an organic compound layer disposed between the first electrode and the second electrode,
10. An organic light-emitting device, wherein the organic compound layer includes the organometallic complex according to any one of Structures 1 to 9.

(Configuration 11)
The organic compound layer is a light emitting layer and further includes a first organic compound different from the organometallic complex,
11. The organic light emitting device according to configuration 10, wherein the first organic compound is a compound having a lowest excited triplet energy higher than that of the organometallic complex.

(Configuration 12)
The light-emitting layer further includes a second organic compound different from the organometallic complex and the first organic compound, and the lowest excited triplet energy of the second organic compound is equal to the lowest excited triplet energy of the organometallic complex. 12. The organic light-emitting device according to configuration 11, wherein the organic light-emitting device has a triplet energy or more and a lowest excited triplet energy of the first organic compound or less.

(Configuration 13)
The organic compound layer includes 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. and further has
13. The organic light emitting device according to

configuration

11 or 12, wherein 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.

(Configuration 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 higher than the lowest excited triplet energy of the first organic compound. 14. The organic light-emitting device according to configuration 13, wherein the organic light-emitting device has a higher triplet energy than the lowest excited triplet energy of one organic compound.

(Configuration 15)
A display comprising a plurality of pixels, at least one of the plurality of pixels including the organic light-emitting element according to any one of Structures 10 to 14, and a transistor connected to the organic light-emitting element. Device.

(Configuration 16)
It has an optical section having a plurality of lenses, an image sensor that receives light that has passed through the optical section, and a display section that displays an image captured by the image sensor,
An imaging device characterized in that the display section includes the organic light emitting device according to any one of Structures 10 to 14.

(Configuration 17)
A display unit including the organic light emitting element according to any one of configurations 10 to 14, a casing in which the display unit is provided, and a communication unit provided in the casing and communicating with the outside. An electronic device featuring:

(Configuration 18)
An illumination device comprising: a light source having the organic light emitting element according to any one of configurations 10 to 14; and a light diffusion section or an optical filter that transmits light emitted from the light source.

(Configuration 19)
A mobile object comprising: a lamp having the organic light emitting element according to any one of Structures 10 to 14; and a body provided with the lamp.

Examples will be described below. However, the present invention is not limited to these Examples.

[Synthesis of organometallic complexes]
<Synthesis of ligand L1>
Ligand L1 was synthesized using the following reaction formula. The steps are shown below.

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, and tetrakistriphenylphosphine were placed in a 100 ml eggplant flask. After adding 0.12 g (0.1 mmol) of palladium, 30 ml of toluene, 15 ml of ethanol, and 15 ml of 2M aqueous sodium carbonate solution, the temperature was raised from room temperature to 90° C. and stirred for 4 hours. Toluene and water were added to extract the organic layer, magnesium sulfate was added to the obtained organic layer, and the mixture was filtered. The filtrate was concentrated and purified by silica gel column chromatography (mobile phase: chloroform). The solvent was distilled off, and the residue was crystallized from an aqueous isopropyl alcohol (IPA) solution to obtain 3.00 g of the compound. It was confirmed by NMR that the obtained compound was the ligand L1 of organometallic complex (1).

<Synthesis of intermediate (1)>
Intermediate (1) was synthesized from ligand L2 according to the following reaction formula. The steps are shown below.

In a nitrogen atmosphere, 3.20 g (22.0 mmol) of 1-phenylpyrazole as the ligand L2, 3.50 g (10 mmol) of iridium chloride trihydrate, 30 ml of 2-ethoxyethanol, and 10 ml and 200 ml of pure water. Added to eggplant flask. This solution was heated from room temperature to 120°C and stirred for 20 hours. Water was added and the precipitated solid was filtered. The filtered solid was washed with methanol and hexane to obtain 5.00 g of intermediate (1).

<Synthesis of intermediate (2)>
Intermediate (2) was synthesized from intermediate (1) according to the following reaction formula. The steps are shown below

In a round bottom flask, 1.00 g (1.00 mmol) of intermediate (1) was dissolved in 20 ml of dichloromethane. In a separate flask, 0.500 g (2.00 mmol) of silver (I) triflate was dissolved in 40 ml of MeOH. This was added slowly to the dimer solution under continuous stirring at room temperature. The reaction mixture was stirred in the dark overnight and then filtered through a closely packed bed of Celite® to remove the silver chloride precipitate. The solvent was removed under reduced pressure to yield 1.40 g (100%) of a yellow-green solid, which was used without further purification.

<Synthesis of organometallic complexes>
Organometallic complex (1) was synthesized from ligand L1 and intermediate (2) according to the following reaction formula.

1.40 g (1.00 mmol) of intermediate (2) and 0.300 g (1.00 mmol) of ligand L1, 25 ml of ethanol, and 25 ml of methanol were added to the flask. The reaction mixture was refluxed for 36 hours, yielding a yellow precipitate. The reaction mixture was cooled to room temperature, diluted with ethanol, Celite® was added, and the mixture was stirred for 10 minutes. The resulting mixture was filtered through a small plug of silica gel on a frit and washed with ethanol (3-4 times) and hexane (3-4 times). The filtrate was discarded. The Celite®/silica plug was then washed with dichloromethane to dissolve the product. Half of the dichloromethane was removed under reduced pressure and hexane was added to precipitate the product, which was filtered and washed with hexane. The crude product was chromatographed on silica gel using 7/3 dichloromethane/hexane by volume, followed by sublimation to yield 0.230 g (34% by weight) of product as a yellow solid. It was confirmed by NMR that the product was the organometallic complex (1).

[ ¹ H NMR (400 MHz, CDCl3)] δ: 9.04 (d, J = 4.8 Hz, 1H), 8.04 (d, J = 4.8 Hz, 2H), 7.83 (d, J = 7.5Hz, 2H), 7.77 (d, J = 7.5Hz, 2H), 7.55-7.50 (m, 2H), 7.45 (d, J = 7.5Hz, 2H), 7.37-7.20 (m, 6H), 7.00-6.80 (m, 4H), 1.45 (s, 9H)

Organometallic complexes (13), (14), (16), organometallic complexes (17), (27), (29), (36), (37) were prepared in the same manner as the above organometallic complex (1). , (47), (63), and (70) were synthesized. Moreover, comparative compounds (1) to (10) are shown below.

Tables 3 and 4 show the 5% weight loss temperature (T5) in the thermogravimetric analysis (TG) curve of each organometallic complex. In addition, Table 3 shows the energy levels of the LUMO and HOMO of Ir(L1) ₃ , which is composed only of the ligand L1, and Ir(L2) ₃ , which is composed only of the ligand L2, in each organometallic complex. , shown in Table 4. In Tables 3 and 4, the column "L1" indicates the energy level of Ir(L1) ₃ and the column "L2" indicates the energy level of Ir(L2) ₃ .

Furthermore, "the LUMO level of Ir(L1) ₃ is deeper than the LUMO level of Ir(L2) ₃ , and the HOMO level of Ir(L1) ₃ is shallower than the HOMO level of Ir(L2) _3. " Those that satisfy the relationship conditions are marked as “〇”, and those that are not satisfied are marked as “×”. Further, Tables 3 and 4 show the maximum emission wavelength and half-value width when the emission spectrum was measured in toluene.

From the data on organometallic complexes in Tables 3 and 4, it is clear that organometallic complexes (1) and (13) are composed of two types of ligands, rather than comparative compound (1), which is composed of the same ligand. , (14), (16), (17), (27), (29), (36), (37), (47), (63), (70) and comparative compounds (2), (3 ), (4), (6), (7), (8), (9), and (10) have a lower 5% weight loss temperature (T5) in the thermogravimetric analysis (TG) curve.

Furthermore, "The LUMO level of Ir(L1) ₃ is deeper than the LUMO level of Ir(L2) ₃ , and the HOMO level of Ir(L1) ₃ is shallower than the HOMO level of Ir(L2) _3. " Organometallic complexes (1), (13), (14), (16), (17), (27), (29), (36), (37), (47) that satisfy the conditions of the present invention: ), (63), and (70) show narrower half-widths than the comparative compounds in which the ligand L1 or the ligand L2 has a similar structure but do not satisfy the conditions of the present invention. For example, it can be seen that the organometallic complex (1) exhibits a narrower half-value width than the comparative compounds (2), (3), and (6) having the same structure of the ligand L1. It can be seen that the organometallic complex (13) exhibits a narrower half-width than the comparative compounds (2), (3), (4), and (6) in which the structure of the ligand L1 is similar. It can be seen that the organometallic complexes (14) and (16) exhibit narrower half-widths than the comparative compound (6) in which the structures of the ligands L1 and L2 are similar. It can be seen that the organometallic complex (17) exhibits a narrower half-value width than the comparative compounds (2), (3), and (6) having the same structure of the ligand L1. It can be seen that the organometallic complex (27) exhibits a narrower half-width than the comparative compounds (3), (4), and (6) in which the structure of the ligand L2 is similar. It can be seen that the organometallic complex (29) exhibits a narrower half-width than the comparative compounds (2), (3), and (6) in which the structure of the ligand L1 is the same. It can be seen that the organometallic complex (36) exhibits a narrower half-width than the comparative compounds (3), (4), and (6) in which the structure of the ligand L2 is similar. It can be seen that the organometallic complex (37) exhibits a narrower half-width than the comparative compound (7) having the same structure of the ligand L1. It can be seen that the organometallic complex (47) exhibits a narrower half-width than the comparative compound (8) having the same structure of the ligand L1. It can be seen that the organometallic complex (63) exhibits a narrower half-width than the comparative compound (9) having the same structure of the ligand L1. It can be seen that the organometallic complex (70) exhibits a narrower half-width than the comparative compounds (5), (7), (8), and (10) in which the structure of the ligand L2 is the same or similar. . It can be seen that the compound has a narrower half-width than the comparative compounds (2), (3), and (4). In particular, it can be seen that organometallic complexes (1), (17), (27), (29), (36), and (47) exhibit narrow half-widths.

From the above data, it can be seen that the organometallic complex according to the present invention achieves both a low sublimation temperature and high color purity.

[Examples (1) to (8) and Comparative Examples (1) to (4)]
The organometallic complex synthesized above and the comparative compound were purified by sublimation at 3×10 ⁻³ Pa. The purity of each organometallic complex was measured by HPLC, and the results were as follows.
Organometallic complex (1): 99.6% by mass
Organometallic complex (13): 99.3% by mass
Organometallic complex (14): 99.2% by mass
Organometallic complex (16): 99.5% by mass
Organometallic complex (17): 99.6% by mass
Organometallic complex (27): 99.4% by mass
Organometallic complex (29): 99.3% by mass
Organometallic complex (36): 99.1% by mass
Comparative compound (1): 99.8% by mass
Comparative compound (2): 99.4% by mass
Comparative compound (3): 99.2% by mass
Comparative compound (4): 99.6% by mass

Using the above sublimated organometallic complex, an organic light emitting device having a structure of anode/hole injection layer/hole transport layer/light emitting layer/electron transport layer/cathode in this order on a substrate was fabricated as follows.

A transparent conductive support substrate (ITO substrate) in which an ITO film was formed as an anode to a thickness of 100 nm by sputtering on a glass substrate was used. On this ITO substrate, an organic compound layer and an electrode layer (thickness in parentheses) shown below were continuously formed by vacuum evaporation using resistance heating in a vacuum chamber of 1×10 ⁻⁵ Pa. At this time, the facing electrodes were manufactured so that the area was 3 mm ² .
Hole injection layer: HT16 (10nm)
Hole transport layer: HT1 (40nm)
Luminous layer:
Host: EM32
Guest: Organometallic complex (4% by mass in the light emitting layer)
Electron transport layer: ET20 (30nm)
cathode:
LiF (15nm)
Al (200nm)

Next, to prevent the organic light emitting device from deteriorating due to moisture adsorption, it was covered with a protective glass plate in a dry air atmosphere and sealed with an acrylic resin adhesive.

The EL spectrum of the obtained organic light-emitting device was measured using the ITO electrode as the anode and the Al electrode as the cathode, and the maximum absorption wavelength and half-value width were calculated. The measurement results are shown in Table 5 below.

From Table 5, it can be seen that the organic light emitting devices of Examples 1 to 8 emit deep green light and have narrower half-widths than the organic light emitting devices of Comparative Examples 1 to 4.

The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the present invention. Therefore, the following claims are appended to set forth the scope of the invention.

This application claims priority based on Japanese Patent Application No. 2022-056127 filed on March 30, 2022 and Japanese Patent Application No. 2023-029569 filed on February 28, 2023. The entire contents thereof are hereby incorporated by reference.

4, 22

Organic compound layer

8, 26 Organic light emitting element 100

Display device

1104, 1203

Housing

1201, 1302, 1311, 1312 Display section 1404 Optical filter 1045 Light diffusion section 1601 Lens

Claims

An iridium complex represented by the following general formula [1], the energy level of the LUMO of Ir(L1) 3 is deeper than the energy level of the LUMO of Ir(L2) 3 , and the HOMO of Ir(L1) 3 An organometallic complex characterized in that its energy level is shallower than the HOMO energy level of Ir(L2) 3 .
Ir(L1)m(L2)n [1]
In the above formula [1], L1 and L2 are different bidentate ligands, m and n are 1 or 2, and m+n=3.
The 5% weight loss temperature (T5) of Ir(L1) 3 or Ir(L2) 3 in the thermogravimetric analysis (TG) curve is equal to or higher than T5 of the iridium complex represented by the general formula [1]. The organometallic complex according to claim 1.
The organometallic complex according to claim 1, wherein the L1 is represented by the following general formula [2].

In the above formula [2], X 1 to X 10 are carbon atoms or nitrogen atoms.
R 1 to R 3 are each independently a hydrogen atom, a deuterium atom, a halogen atom, an alkyl group, a cycloalkyl group, a heteroalkyl group, an arylalkyl group, an alkoxy group, an aryloxy group, an amino group, a silyl group, Alkenyl group, cycloalkenyl group, heteroalkenyl group, alkynyl group, aryl group, heteroaryl group, acyl group, carboxylic acid residue, ester group, nitrile group, isonitrile group, sulfanyl group, sulfonic acid residue, phosphino group, boronyl and combinations thereof. Furthermore, R 1 and R 2 may be bonded to each other to form a ring structure.
Y is an oxygen atom, a sulfur atom, CR 6 R 7 , CR 6 =CR 7 , NR 6 , BR 6 , SiR 6 R 7 , C=O, C=NR 6 , C=CR 6 R 6 , S=O, is a divalent bridging group selected from the group consisting of SO 2 , CR 6 R 7 -CR 6 R 7 , PR 6 and P(=O)R 6 , and R 6 and R 7 are each independently a straight selected from the group consisting of chain alkyl groups, branched alkyl groups, and aryl groups.
The organometallic complex according to claim 3, wherein in the formula [2], X 1 to X 10 are carbon atoms.
The organometallic complex according to claim 4, wherein in the formula [2], R 1 other than a hydrogen atom is substituted at the 4-position of the pyridine ring.
The organometallic complex according to claim 1, wherein the L2 is represented by the following general formula [3].

In the above formula [3], X 11 to X 17 are carbon atoms or nitrogen atoms, and any one or more of X 15 to X 17 is a nitrogen atom.
R 4 and R 5 each independently represent a hydrogen atom, a deuterium atom, a halogen atom, an alkyl group, a cycloalkyl group, a heteroalkyl group, an arylalkyl group, an alkoxy group, an aryloxy group, an amino group, a silyl group, From alkenyl groups, cycloalkenyl groups, heteroalkenyl groups, alkynyl groups, aryl groups, heteroaryl groups, acyl groups, carboxylic acid residues, ester groups, nitrile groups, isonitrile groups, sulfanyl groups, sulfonic acid residues, and combinations thereof. Adjacent substituents may be bonded to each other to form a ring structure.
The organometallic complex according to claim 6, wherein in the formula [3], X 15 is a nitrogen atom, and X 11 to X 14 and X 16 to X 17 are carbon atoms.
The organometallic complex according to claim 6, wherein in the formula [3], R5 is a hydrogen atom, an alkyl group, or a cycloalkyl group.
The organometallic complex according to claim 8, wherein the organometallic complex is one of the following formulas [4] to [8].
An organic light emitting device comprising a first electrode, a second electrode, and an organic compound layer disposed between the first electrode and the second electrode,
An organic light emitting device, wherein the organic compound layer contains the organometallic complex according to any one of claims 1 to 9.
The organic compound layer is a light emitting layer and further includes a first organic compound different from the organometallic complex,
11. The organic light emitting device according to claim 10, wherein the first organic compound is a compound having a lowest excited triplet energy higher than that of the organometallic complex.
The light-emitting layer further includes a second organic compound different from the organometallic complex and the first organic compound, and the lowest excited triplet energy of the second organic compound is equal to the lowest excited triplet energy of the organometallic complex. The organic light emitting device according to claim 11, wherein the organic light emitting device has a triplet energy or more and a lowest excitation triplet energy of the first organic compound or less.
The organic compound layer includes 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. and further has
The organic light emitting device according to claim 11, wherein 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 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 higher than the lowest excited triplet energy of the first organic compound. 14. The organic light emitting device according to claim 13, wherein the organic light emitting device has a higher triplet energy than the lowest excited triplet energy of one organic compound.
A display device comprising a plurality of pixels, at least one of the plurality of pixels comprising the organic light emitting element according to claim 10 and a transistor connected to the organic light emitting element.
It has an optical section having a plurality of lenses, an image sensor that receives light that has passed through the optical section, and a display section that displays an image captured by the image sensor,
An imaging device, wherein the display section includes the organic light emitting device according to claim 10.
An electronic device comprising: a display section having the organic light emitting element according to claim 10; a casing in which the display section is provided; and a communication section provided in the casing and communicating with the outside. .
A lighting device comprising: a light source having the organic light emitting element according to claim 10; and a light diffusion section or optical filter that transmits light emitted from the light source.
A mobile object comprising: a lamp having the organic light emitting element according to claim 10; and a body provided with the lamp.