Light-emitting element

Abstract

To provide a light-emitting element with high luminous efficiency and reliability.SOLUTION: A light-emitting element includes a host material and a guest material in a light-emitting layer. The host material has a function of converting triplet excitation energy into light emission, and the guest material emits fluorescence. A molecular structure of the guest material has a light-emitting group and a protective group, and one molecule of the guest material includes five or more protective groups. By introducing the protective groups into the molecule, the energy shift of the triplet excitation energy due to a dexter mechanism from the host material to the guest material is suppressed. As the protective group, an alkyl group or a branched chain alkyl group is used.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] One embodiment of the present invention is a light-emitting element, an organic compound, or a display device including the light-emitting element, an electronic device, or This document relates to lighting fixtures and lighting equipment.

[0002] Note that one embodiment of the present invention is not limited to the above technical fields. The technical field of one aspect of the present invention relates to an article, a method, or a manufacturing method. is a process, machine, manufacture, or composition of matter. Therefore, the technical field of one embodiment of the present invention disclosed in this specification more specifically relates to Examples of the semiconductor device include a semiconductor device, a display device, a liquid crystal display device, a light-emitting device, a lighting device, a power storage device, a memory device, and the like. Examples include devices, methods for driving them, and methods for manufacturing them. . [Background technology]

[0003] In recent years, electroluminescence (EL) The basic structure of these light-emitting devices is as follows: The device has a structure in which a layer containing a light-emitting substance (EL layer) is sandwiched between a pair of electrodes. By applying a voltage between them, light is emitted from the luminescent material.

[0004] Since the above-mentioned light-emitting element is a self-luminous type, a display device using it has excellent visibility and It has the advantage of not requiring a light source and consuming little power. It also has the advantage of high response speed.

[0005] An EL device that uses an organic compound as the luminescent material and contains the luminescent organic compound between a pair of electrodes In the case of a light-emitting element (for example, an organic EL element) having a layer, a voltage is applied between a pair of electrodes. As a result, electrons are injected from the cathode and holes are injected from the anode into the light-emitting EL layer. The injected electrons and holes are then recombined to form a luminescent The organic compound is excited, and light can be emitted from the excited luminescent organic compound. do.

[0006] The types of excited states that organic compounds can form include singlet excited states (S * ) and triplet excitation Condition (T * ) and emission from the singlet excited state is fluorescence, and emission from the triplet excited state is phosphorescence. The statistical generation rate of these light sources in a light-emitting device is S * :T * = Therefore, it is more effective to use phosphorescent light than to use fluorescent compounds (fluorescent materials). Light-emitting elements that use light-emitting compounds (phosphorescent materials) can achieve higher luminous efficiency. Therefore, it is possible to convert the energy of the triplet excited state into light emission. 2. Description of the Related Art In recent years, the development of light-emitting devices using conductive materials has been actively pursued.

[0007] Among light-emitting elements using phosphorescent materials, light-emitting elements that emit blue light have high However, it is difficult to develop stable compounds with high triplet excited energy levels, and so they have not yet been put to practical use. Therefore, light-emitting devices using more stable fluorescent materials are being developed. Therefore, methods for increasing the luminous efficiency of light-emitting elements using fluorescent materials (fluorescent light-emitting elements) are being explored. There are.

[0008] A material capable of converting part or all of the energy of the triplet excited state into luminescence. In addition to phosphorescent materials, thermally activated delayed fluorescence (TFA) Thermally activated materials such as TADF (Telephoto Delayed Fluorescence) are known. In the activated delayed fluorescent material, the singlet excited state is generated from the triplet excited state by reverse intersystem crossing. The singlet excited state is converted into light emission.

[0009] In order to improve the luminous efficiency of a light-emitting device using a thermally activated delayed fluorescent material, In the activated delayed fluorescent material, the singlet excited state is efficiently generated from the triplet excited state. Furthermore, it is possible to efficiently obtain light emission from the singlet excited state, i.e., it has a high fluorescence quantum yield. However, it is difficult to design a light-emitting material that satisfies both of these requirements at the same time. It is difficult.

[0010] In addition, in a light-emitting device having a thermally activated delayed fluorescent material and a fluorescent material, The singlet excitation energy of the delayed fluorescent material is transferred to the fluorescent material, and the fluorescent material emits light. A method for obtaining light has been proposed (see Patent Document 1). [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-45179 [Non-patent literature]

[0012] [Non-Patent Document 1] Hiroki Noda et al., “SCIENCE ADVANCES”, 2018, vol. 4, no. 6, eaao6910 Summary of the Invention [Problem to be solved by the invention]

[0013] As described above, in order to improve the efficiency of fluorescent light-emitting devices, for example, a compound having a host material and a guest material is used. In the light-emitting layer, triplet excitons of the host material are converted into singlet excitons, and then the guest material However, the method of transferring singlet excitation energy to a fluorescent material is as follows. The process by which triplet excitation energy of the host material is converted into singlet excitation energy is as follows: Therefore, the triplet excited energy of the host material competes with the deactivation process. In some cases, the energy is not sufficiently converted into singlet excitation energy. For example, One of the pathways for energy loss is the generation of fluorescent materials in the light-emitting layer of a light-emitting device. When used as a photoresist, the lowest triplet excited energy level (T1 level) of the fluorescent material is The triplet excitation energy of the host material is transferred to the ion-excitation site (position 1). Energy transfer via the deactivation pathway does not contribute to light emission, leading to low luminous efficiency in fluorescent light-emitting devices. This deactivation pathway can be suppressed by reducing the concentration of the guest material. In this case, the energy transfer rate from the host material to the singlet excited state of the guest material is also This slows down the light emission rate, making it more susceptible to quenching due to degradation products and impurities. The brightness of the display tends to decrease, resulting in a decrease in reliability.

[0014] Therefore, in order to increase the luminous efficiency of the fluorescent light emitting device and also improve its reliability, The triplet excitation energy can be efficiently converted into singlet excitation energy, and the triplet excitation energy The singlet excitation energy is efficiently transferred to the fluorescent material as singlet excitation energy. Therefore, it is preferable to change the triplet excited state of the host material to the singlet excited state of the guest material. This efficiently generates an excited state, further improving the luminous efficiency of the light-emitting element and also improving reliability. There is a need to develop methods and materials to improve this.

[0015] Therefore, in one embodiment of the present invention, a host material and a guest material of an emitting layer of a light-emitting device are In this case, the triplet excitation energy of the host material is prevented from transferring to the T1 level of the guest material. The triplet excitation energy of the host material is efficiently converted to the singlet excitation energy of the guest material. This will increase the fluorescent efficiency of the light-emitting device and improve its reliability. The purpose is to

[0016] Another object of one embodiment of the present invention is to provide a light-emitting element with reduced power consumption. Another object of one embodiment of the present invention is to provide a novel light-emitting element. An object of one embodiment of the present invention is to provide a novel light-emitting device. In one embodiment, it is an object to provide a novel display device. The objective is to provide

[0017] Note that the above description of the object does not preclude the existence of other objects. It is not necessary to solve all of these problems. Problems other than those mentioned above can be solved by the description of the specification, etc. It is obvious from the description of the specification, etc. that other problems can be extracted. do. [Means for solving the problem]

[0018] As described above, in a fluorescent light-emitting element, triplet excitation energy can be efficiently converted into light emission. Therefore, the development of a method for converting energy between materials used in the light-emitting layer is required. To achieve this, it is necessary to improve the dynamic efficiency of the energy donor-energy accessor. It is necessary to suppress the transfer of triplet excitation energy between the adductors by the Dexter mechanism.

[0019] Therefore, one embodiment of the present invention is a light-emitting element having a light-emitting layer between a pair of electrodes, a first material having a function of converting triplet excitation energy into luminescence; a second material having a function of converting energy into luminescence, the second material comprising a luminophore and five or more The luminophore has the above protecting group, and the luminophore is a fused aromatic ring or a fused heteroaromatic ring, and has five or more protecting groups. are each independently an alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkyl group having 3 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, or a trialkylsilyl group having 3 to 12 carbon atoms. The light-emitting element has either one of the first and second materials and emits light from the second material.

[0020] In the above structure, at least four of the five or more protecting groups are independently selected from the group having 3 carbon atoms. Alkyl groups with 10 or more carbon atoms and substituted or unsubstituted cycloalkyl groups with 3 or more carbon atoms and 10 or less carbon atoms and a trialkylsilyl group having 3 to 12 carbon atoms.

[0021] Another embodiment of the present invention is a light-emitting element having a light-emitting layer between a pair of electrodes, The present invention is based on a first material that converts triplet excitation energy into luminescence, and a second material that converts singlet excitation energy into luminescence. The second material has a function of converting energy into luminescence, and the second material contains a luminophore and at least The luminophore has at least four protecting groups, and the luminophore is a fused aromatic ring or a fused heteroaromatic ring, and the four protecting groups The protecting groups are not directly bonded to the fused aromatic ring or fused heteroaromatic ring, and the four protecting groups are independently alkyl groups having 3 to 10 carbon atoms, substituted or unsubstituted alkyl groups having 3 to 10 carbon atoms a cycloalkyl group or a trialkylsilyl group having 3 to 12 carbon atoms, The second material emits light, making it a light-emitting element.

[0022] Another embodiment of the present invention is a light-emitting element having a light-emitting layer between a pair of electrodes, The present invention is based on a first material that converts triplet excitation energy into luminescence, and a second material that converts singlet excitation energy into luminescence. a second material having a function of converting energy into luminescence, the second material comprising a luminophore and two or more The luminophore has a diarylamino group as above, and the luminophore is a fused aromatic ring or a fused heteroaromatic ring, and the fused The aromatic ring or fused heteroaromatic ring is bonded to two or more diarylamino groups, and two or more diarylamino groups are bonded to the aromatic ring or fused heteroaromatic ring. Each aryl group in the arylamino group independently has at least one protecting group, are each independently an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted alkyl group having 3 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, or a trialkylsilyl group having 3 to 12 carbon atoms; The light-emitting element has either one of the first and second materials and emits light from the second material.

[0023] Another embodiment of the present invention is a light-emitting element having a light-emitting layer between a pair of electrodes, The present invention is based on a first material that converts triplet excitation energy into luminescence, and a second material that converts singlet excitation energy into luminescence. a second material having a function of converting energy into luminescence, the second material comprising a luminophore and two or more The luminophore is a fused aromatic ring or a fused heteroaromatic ring, and the fused The aromatic ring or fused heteroaromatic ring is bonded to two or more diarylamino groups, and two or more diarylamino groups are bonded to the aromatic ring or fused heteroaromatic ring. The aryl groups in the arylamino group each independently have at least two protecting groups, are each independently a branched alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted Cycloalkyl groups with 3 to 10 carbon atoms, and trialkylsilyl groups with 3 to 12 carbon atoms. The light-emitting element has either one of the groups and emits light from the second material.

[0024] In the above structure, the diarylamino group is preferably a diphenylamino group.

[0025] In the above structure, the alkyl group is preferably a branched chain alkyl group.

[0026] Another embodiment of the present invention is a light-emitting element having a light-emitting layer between a pair of electrodes, The present invention relates to a first material having a function of converting triplet excitation energy into luminescence, and a second material having a function of converting singlet excitation energy into luminescence. a second material having a function of converting energy into luminescence, the second material comprising a luminophore and a plurality of The luminophore has a condensed aromatic ring or a condensed heteroaromatic ring, and the luminophore has a plurality of protecting groups. At least one of the atoms is located directly above one face of the fused aromatic ring or fused heteroaromatic ring. and at least one of the atoms constituting the plurality of protecting groups is a fused aromatic ring or a fused heteroaromatic ring. It is a light-emitting element located directly above the other surface of the aromatic ring, and emits light from the second material.

[0027] Another embodiment of the present invention is a light-emitting element having a light-emitting layer between a pair of electrodes, The present invention is based on a first material that converts triplet excitation energy into luminescence, and a second material that converts singlet excitation energy into luminescence. a second material having a function of converting energy into luminescence, the second material comprising a luminophore and two or more The luminophore is a fused aromatic ring or a fused heteroaromatic ring, and the fused The aromatic ring or condensed heteroaromatic ring is bonded to two or more diphenylamino groups, and two or more diphenylamino groups are bonded to the aromatic ring or condensed heteroaromatic ring. The phenyl groups in the phenylamino group each independently have protecting groups at the 3- and 5-positions, and the protecting groups are each independently an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted alkyl group having 3 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, or a trialkylsilyl group having 3 to 12 carbon atoms; The light-emitting element has either one of the first and second materials and emits light from the second material.

[0028] In the above structure, the alkyl group is preferably a branched chain alkyl group.

[0029] In the above structure, the branched chain alkyl group preferably has a quaternary carbon.

[0030] In the above structure, the condensed aromatic ring or the condensed heteroaromatic ring is selected from the group consisting of naphthalene, anthracene, and the like. fluorene, chrysene, triphenylene, pyrene, tetracene, perylene, coumarin It is preferable that the compound contains any one of quinacridone and naphthobisbenzofuran.

[0031] In the above structure, the first material includes a first organic compound and a second organic compound. Preferably, the first organic compound and the second organic compound form an exciplex. More preferably, the compound exhibits phosphorescence.

[0032] In the above structure, the first material preferably exhibits phosphorescence.

[0033] In the above configuration, the emission spectrum of the first material is on the longest wavelength side of the emission spectrum of the second material. It is preferable that the absorption band overlaps with the absorption band.

[0034] In the above structure, the concentration of the second material in the light-emitting layer is 2 wt % or more and 30 wt % or less. It is preferable that:

[0035] Another embodiment of the present invention is an organic compound represented by the following general formula (G1) or (G2): is.

[0036] [ka]

[0037] In the general formulae (G1) and (G2), A is a substituted or unsubstituted fused aromatic ring having 10 to 30 carbon atoms. Ar represents a substituted or unsubstituted fused heteroaromatic ring or a substituted or unsubstituted heteroaromatic ring having 10 to 30 carbon atoms; 1 No To Ar 6 each independently represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms; And X 1 ~X 12 are each independently an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted alkyl group, represents an unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a trialkyl group having 3 to 12 carbon atoms, R represents one of the alkylsilyl groups; 1 ~R 10 are each independently hydrogen, a group having 3 or more carbon atoms, Alkyl groups with 10 or less carbon atoms, substituted or unsubstituted cycloalkyl groups with 3 to 10 carbon atoms a trialkylsilyl group having 3 to 12 carbon atoms;

[0038] In the above-mentioned structure, the organic compound is represented by the following general formula (G3) or (G4): An organic compound is preferred.

[0039] [ka]

[0040] In the general formulae (G3) and (G4), A is a substituted or unsubstituted fused aromatic ring having 10 to 30 carbon atoms. X represents a substituted or unsubstituted fused heteroaromatic ring or a substituted or unsubstituted heteroaromatic ring having 10 to 30 carbon atoms;1 ~ X 12 are each independently an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted carbon atom, Cycloalkyl groups with a prime number of 3 or more and 10 or less, and trialkylsilyl groups with a carbon number of 3 or more and 12 or less R represents one of the following: 1 , R 3 , R 6 and R 8 are each independently hydrogen, a group having 3 or more carbon atoms Alkyl groups with 10 or less carbon atoms, substituted or unsubstituted cycloalkyl groups with 3 to 10 carbon atoms , or a trialkylsilyl group having 3 to 12 carbon atoms.

[0041] In the above structure, the organic compound is an organic compound represented by the following general formula (G5): It is preferable to do so.

[0042] [ka]

[0043] In general formula (G5), X 1 ~X 8 are each independently an alkyl group having 3 to 10 carbon atoms. , substituted or unsubstituted cycloalkyl groups having 3 to 10 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms represents one of the following trialkylsilyl groups, and R 11 ~R 18 are each independently alkyl groups having 3 to 10 carbon atoms; substituted or unsubstituted alkyl groups having 3 to 10 carbon atoms; Cycloalkyl groups, trialkylsilyl groups with 3 to 12 carbon atoms, substituted or unsubstituted represents any one of the aryl groups having 6 to 25 carbon atoms.

[0044] In the above structure, the alkyl group is preferably a branched chain alkyl group.

[0045] In the above structure, the branched alkyl preferably has a quaternary carbon.

[0046] In the above structure, the organic compound is represented by the following structural formulas (102) to (104), (22 1), (222), (225), (229), (250), (254), (257), ( It is more preferable that the organic compound is represented by either one of (261) and (264).

[0047] [ka]

[0048] [ka]

[0049] [ka]

[0050] Another embodiment of the present invention is a light-emitting element using one or more of the above organic compounds. is.

[0051] Another embodiment of the present invention is a light-emitting element having any of the above structures, a color filter or a transistor, and a light-emitting element. and at least one of a first transistor and a second transistor. The electronic device includes the display device and at least one of a housing and a touch sensor. Another embodiment of the present invention is a light-emitting element having any of the above structures, a housing, or a touch sensor. Another embodiment of the present invention is a lighting device having a light-emitting element. Not only optical devices but also electronic devices having light-emitting devices are included in the category. The light-emitting device in this context refers to an image display device or a light source (including a lighting device). Connectors for optical devices, such as FPC (Flexible Printed Circuit) t), TCP (Tape Carrier Package) mounted display module module, a display module with a printed wiring board at the end of the TCP, or a light-emitting element with C Display with IC (Integrated Circuit) directly mounted using OG (Chip On Glass) method The module may also include a light emitting (display) device. [Effects of the Invention]

[0052] According to one embodiment of the present invention, a light-emitting element with high emission efficiency can be provided. In one embodiment of the present invention, a highly reliable light-emitting element can be provided. In this embodiment, a light-emitting element with reduced power consumption can be provided. In this manner, a novel light-emitting element can be provided. Alternatively, in one embodiment of the present invention, a novel display device can be provided. Alternatively, a novel organic compound can be provided.

[0053] The description of these effects does not preclude the existence of other effects. It is not necessary to have all of these effects. Effects other than these may be included in the description. It is obvious from the description of the specification, drawings, claims, etc. From this, it is possible to extract other effects. [Brief explanation of the drawings]

[0054] [Figure 1]1A and 1B are schematic cross-sectional views of a light-emitting layer of a light-emitting element of one embodiment of the present invention and a diagram illustrating the correlation between energy levels. [Figure 2] 1A and 1B are conceptual diagrams of a conventional guest material and a guest material used in a light-emitting element of one embodiment of the present invention. [Figure 3] 1A and 1B show structural formulas and ball-and-stick diagrams of guest materials used in light-emitting elements of one embodiment of the present invention. [Figure 4] 1A and 1B are schematic cross-sectional views of a light-emitting layer of a light-emitting element of one embodiment of the present invention and a diagram illustrating the correlation between energy levels. [Figure 5] 1A and 1B are schematic cross-sectional views of a light-emitting layer of a light-emitting element of one embodiment of the present invention and a diagram illustrating the correlation between energy levels. [Figure 6] 1A and 1B are schematic cross-sectional views of a light-emitting layer of a light-emitting element of one embodiment of the present invention and a diagram illustrating the correlation between energy levels. [Figure 7] 1A and 1B are schematic cross-sectional views of a light-emitting element according to one embodiment of the present invention. [Figure 8] 1A and 1B are a top view and a cross-sectional view schematic diagram illustrating a display device of one embodiment of the present invention. [Figure 9] 1A and 1B are schematic cross-sectional views illustrating a display device according to one embodiment of the present invention. [Figure 10] 1A and 1B are schematic cross-sectional views illustrating a display device according to one embodiment of the present invention. [Figure 11] FIG. 1 is a perspective view illustrating a display module of one embodiment of the present invention. [Figure 12] 1A to 1C illustrate electronic devices of one embodiment of the present invention. [Figure 13] FIG. 1 is a perspective view illustrating a display device according to one embodiment of the present invention. [Figure 14] 1A to 1C illustrate a lighting device according to one embodiment of the present invention. [Figure 15] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 16] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 17] FIG. 2 is a diagram illustrating absorption and emission spectra of compounds according to an example. [Figure 18] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 19]FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 20] FIG. 2 is a diagram illustrating absorption and emission spectra of compounds according to an example. [Figure 21] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 22] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 23] FIG. 2 is a diagram illustrating absorption and emission spectra of compounds according to an example. [Figure 24] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 25] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 26] FIG. 2 is a diagram illustrating absorption and emission spectra of compounds according to an example. [Figure 27] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 28] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 29] FIG. 2 is a diagram illustrating absorption and emission spectra of compounds according to an example. [Figure 30] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 31] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 32] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 33] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 34] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 35] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 36] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 37] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 38] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 39] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 40] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 41] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 42] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 43] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 44] FIG. 10 is a graph illustrating the relationship between external quantum efficiency and guest material concentration according to an embodiment. [Figure 45] 10A and 10B are diagrams illustrating the results of measuring the luminescence lifetime of a light-emitting element according to an example. [Figure 46] 10A and 10B are diagrams illustrating the results of measuring the luminescence lifetime of a light-emitting element according to an example. [Figure 47] 10A and 10B are diagrams illustrating the results of measuring the luminescence lifetime of a light-emitting element according to an example. [Figure 48] 10A and 10B are diagrams illustrating the results of measuring the luminescence lifetime of a light-emitting element according to an example. [Figure 49] 10A and 10B are diagrams illustrating the results of measuring the luminescence lifetime of a light-emitting element according to an example. [Figure 50] 10A and 10B are diagrams illustrating the results of measuring the luminescence lifetime of a light-emitting element according to an example. [Figure 51] 10A and 10B are diagrams illustrating the results of measuring the luminescence lifetime of a light-emitting element according to an example. [Figure 52] 10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Figure 53] 10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Figure 54] 10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Figure 55] 10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Figure 56]FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 57] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 58] 10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Figure 59] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 60] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 61] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 62] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 63] FIG. 10 is a graph illustrating the relationship between external quantum efficiency and guest material concentration according to an embodiment. [Figure 64] 10A and 10B are diagrams illustrating the results of measuring the luminescence lifetime of a light-emitting element according to an example. [Figure 65] 10A and 10B are diagrams illustrating the results of measuring the luminescence lifetime of a light-emitting element according to an example. [Figure 66] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to a reference example. [Figure 67] FIG. 10 is a graph showing electroluminescence spectra of a light-emitting element according to a reference example. [Figure 68] FIG. 10 is a graph illustrating the relationship between external quantum efficiency and guest material concentration according to a reference example. [Figure 69] 10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Figure 70] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 71] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 72] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 73] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 74] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 75] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 76] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 77] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 78] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 79] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 80] FIG. 2 is a diagram illustrating absorption and emission spectra of compounds according to an example. [Figure 81] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 82] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 83] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 84] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 85] FIG. 2 is a diagram illustrating absorption and emission spectra of compounds according to an example. [Figure 86] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 87] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 88] FIG. 2 is a diagram illustrating absorption and emission spectra of compounds according to an example. [Figure 89] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 90] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 91] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 92] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 93] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 94] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 95] FIG. 2 is a diagram illustrating absorption and emission spectra of compounds according to an example. [Figure 96] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 97] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 98] FIG. 2 is a diagram illustrating absorption and emission spectra of compounds according to an example. [Figure 99] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 100] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 101] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 102] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 103] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 104] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 105] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 106] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 107] FIG. 2 is a diagram illustrating absorption and emission spectra of compounds according to an example. [Figure 108] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 109] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 110] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 111] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 112] FIG. 2 is a diagram illustrating absorption and emission spectra of compounds according to an example. [Figure 113]FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 114] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 115] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 116] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 117] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 118] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 119] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 120] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 121] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 122] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 123] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 124] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 125] FIG. 10 is a graph showing electroluminescence spectra of comparative light-emitting elements according to examples. [Figure 126] FIG. 10 is a graph illustrating the relationship between external quantum efficiency and guest material concentration according to an embodiment. [Figure 127] 10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Figure 128] 10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Figure 129] 10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Figure 130] 10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Figure 131]10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Figure 132] 10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Figure 133] 10A and 10B are diagrams illustrating the reliability measurement results of a comparative light-emitting element according to an example. [Figure 134] 10A and 10B are diagrams illustrating the results of measuring the luminescence lifetime of a light-emitting element according to an example. [Figure 135] 10A and 10B are diagrams illustrating the results of measuring the luminescence lifetime of a light-emitting element according to an example. [Figure 136] 10A and 10B are diagrams illustrating the results of measuring the luminescence lifetime of a comparative light-emitting element according to an example. [Figure 137] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 138] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 139] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 140] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 141] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 142] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 143] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 144] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 145] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 146] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 147] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 148] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 149]FIG. 10 is a graph illustrating the relationship between external quantum efficiency and guest material concentration according to an embodiment. [Figure 150] 10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Figure 151] 10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Figure 152] 10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Figure 153] 10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Fig. 154] 10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Figure 155] 10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Figure 156] 10A and 10B are diagrams illustrating the results of measuring the luminescence lifetime of a light-emitting element according to an example. [Figure 157] 10A and 10B are diagrams illustrating the results of measuring the luminescence lifetime of a light-emitting element according to an example. [Figure 158] 10A and 10B are diagrams illustrating the results of measuring the luminescence lifetime of a light-emitting element according to an example. [Figure 159] 10A and 10B are diagrams illustrating the results of measuring the luminescence lifetime of a light-emitting element according to an example. [Figure 160] 10A and 10B are diagrams illustrating the results of measuring the luminescence lifetime of a light-emitting element according to an example. [Figure 161] FIG. 2 is a diagram illustrating the relationship between the emission of an energy donor and the absorption of a guest material according to an embodiment. [Figure 162] FIG. 2 is a diagram illustrating the relationship between the emission of an energy donor and the absorption of a guest material according to an embodiment. [Figure 163] FIG. 2 is a diagram illustrating the relationship between the emission of an energy donor and the absorption of a guest material according to an embodiment. [Fig. 164] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 165] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 166] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 167] FIG. 1 is a diagram illustrating an NMR chart of a compound according to an example. [Figure 168] FIG. 2 is a diagram illustrating absorption and emission spectra of compounds according to an example. [Figure 169] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 170] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 171] FIG. 10 is a graph illustrating the relationship between external quantum efficiency and guest material concentration according to an embodiment. [Fig. 172] 10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Fig. 173] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Fig. 174] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 175] FIG. 2 is a diagram illustrating the relationship between the emission of an energy donor and the absorption of a guest material according to an embodiment. [Figure 176] FIG. 10 is a graph illustrating the relationship between external quantum efficiency and guest material concentration according to an embodiment. [Figure 177] 10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Figure 178] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 179] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 180] 10A to 10C are diagrams illustrating measurement results of reliability of light-emitting elements according to an example. [Figure 181] 10A and 10B are diagrams illustrating the results of measuring the luminescence lifetime of a light-emitting element according to an example. [Figure 182] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 183] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 184] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 185] FIG. 2 is a diagram illustrating the relationship between the emission of an energy donor and the absorption of a guest material according to an embodiment. [Figure 186] FIG. 10 is a graph illustrating the relationship between external quantum efficiency and guest material concentration according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0055] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the above description, and the embodiments and details thereof may be modified without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the embodiments described below. The terms and conditions of the present invention are not to be construed as being limited to the content.

[0056] In addition, the position, size, range, etc. of each component shown in the drawings etc. are not necessarily shown in order to facilitate understanding. It may not represent the actual position, size, range, etc. Therefore, the disclosed invention The position, size, range, etc. are not necessarily limited to those disclosed in the drawings, etc.

[0057] In addition, in this specification, ordinal numbers such as 1st, 2nd, etc. are used for convenience, In some cases, the order of processes or layers may not be indicated. For example, "first" may be replaced with "second" or " can be appropriately replaced with "third" etc. The ordinal numbers used to identify an aspect of the present invention may not match. be.

[0058] In addition, in this specification and the like, when explaining the configuration of the invention using drawings, the same The reference numerals may be commonly used even among different drawings.

[0059] In addition, in this specification and the like, the terms "film" and "layer" are interchangeable. For example, the term "conductive layer" can be changed to the term "conductive film." Alternatively, for example, the term "insulating film" may be changed to "insulating layer" It may be possible to change the term to

[0060] In this specification and the like, the singlet excited state (S * ) is a single atom with excitation energy The S1 level is the lowest singlet excited energy level. , the lowest excited energy level of the singlet state (S1 state). term excited state (T * ) is a triplet state with excitation energy. The lowest triplet excited energy level is the lowest triplet excited state (T1 In this specification, the term "singlet excited state" is used to refer to the excited energy level of the singlet excited state. Even when written as S1 state and S2 level, Also, the triplet excited state and triplet excited energy level are sometimes used. Even in this case, it may refer to the T1 state and T1 level.

[0061] In this specification and the like, the fluorescent material is a material that emits light when it relaxes from a singlet excited state to a ground state. Phosphorescent materials are compounds that emit light in the visible light region. When the compound relaxes to the phosphorus state, it emits light in the visible light region at room temperature. A photoactive material is a compound that can convert triplet excitation energy into visible light.

[0062] In this specification and the like, room temperature refers to a temperature in the range of 0°C or higher and 40°C or lower.

[0063] In this specification, the blue wavelength range is 400 nm or more and less than 490 nm. The blue light emission has at least one emission spectrum peak in the wavelength region. The green wavelength region is 490 nm or more and less than 580 nm, and green light is emitted in this wavelength region. It has at least one emission spectrum peak. The red wavelength region is 580 nm. The red light has at least one emission spectrum in the wavelength range of 680 nm or more and 680 nm or less. It has a peak.

[0064] (Embodiment 1) In this embodiment, a light-emitting element of one embodiment of the present invention will be described below with reference to FIGS. Reveal.

[0065] <Configuration example of light-emitting element> First, the structure of a light-emitting element of one embodiment of the present invention will be described below with reference to FIG.

[0066] FIG. 1A is a schematic cross-sectional view of a light-emitting element 150 of one embodiment of the present invention.

[0067] The light emitting element 150 has a pair of electrodes (electrode 101 and electrode 102), and The EL layer 100 has at least a light-emitting layer 130. .

[0068] The EL layer 100 shown in FIG. 1A includes a hole injection layer 111, a positive electrode layer 112, a positive electrode layer 113, a positive electrode layer 114, a positive electrode layer 115, a positive electrode layer 116, a positive electrode layer 117, a positive electrode layer 118, a positive electrode layer 119 ... It has functional layers such as a hole transport layer 112, an electron transport layer 118, and an electron injection layer 119.

[0069] In this embodiment, of the pair of electrodes, electrode 101 is the anode, and electrode 1 Although the description will be given assuming that O2 is a cathode, the configuration of the light emitting element 150 is not limited to this. The electrode 101 is the cathode, the electrode 102 is the anode, and the layers between the electrodes are stacked in the reverse order. That is, from the anode side, the hole injection layer 111, the hole transport layer 112, and the light emitting layer 113 may be arranged in this order. The light-emitting layer 130, the electron transport layer 118, and the electron injection layer 119 may be stacked in this order. .

[0070] The configuration of the EL layer 100 is not limited to the configuration shown in FIG. 1(A). , a hole transport layer 112, an electron transport layer 118, and an electron injection layer 119. Alternatively, the EL layer 100 may be configured to have either a hole or electron injection layer. Reduce the barrier, improve the transportability of holes or electrons, or inhibit the transportability of holes or electrons or suppressing the quenching phenomenon caused by the electrode. The functional layers may each be a single layer or may be a laminate of multiple layers. It may be composed of

[0071] <Light-emitting mechanism of light-emitting elements> Next, the light emitting mechanism of the light emitting layer 130 will be described below.

[0072] In the light-emitting element 150 of one embodiment of the present invention, a pair of electrodes (electrode 101 and electrode 102) By applying a voltage between the cathode and the anode, electrons flow from the cathode and holes flow from the anode. The electrons are injected into the EL layer 100, causing a current to flow. The ratio of singlet excitons to triplet excitons (hereafter referred to as exciton generation probability) is The statistical probability is 1:3, i.e., the rate at which singlet excitons are generated is 25%. Since the rate at which triplet excitons are generated is 75%, the triplet excitons are expected to contribute to light emission. It is important to improve the light emitting efficiency of the light emitting device. For 0, it is preferable to use a material that has the function of converting triplet excitation energy into luminescence.

[0073] As a material that has the function of converting triplet excitation energy into luminescence, phosphorescence is In this specification and the like, the term "phosphorescent material" refers to a compound that can emit light. The material is a material that can be used in a temperature range above low temperature (e.g., 77K) and below room temperature (i.e., above 77K and 313 K or less), a compound that exhibits phosphorescence but does not exhibit fluorescence. The phosphorescent material preferably contains a metal element with a large spin-orbit interaction. Transition metal elements are preferred, especially platinum group elements (ruthenium (Ru), rhodium (Rh) , palladium (Pd), osmium (Os), iridium (Ir), or platinum (Pt) ), and among them, by containing iridium, the singlet ground state and the triplet This is preferable because it can increase the transition probability involved in the direct transition between excited states.

[0074] In addition, TADF materials are materials that have the function of converting triplet excitation energy into light emission. TADF materials are materials in which the difference between the S1 level and the T1 level is small and the inverse interphase The crossover converts energy from triplet excitation energy to singlet excitation energy. Therefore, triplet excitation energy can be converted to ZnO by a small amount of thermal energy. The singlet excited state can be upconverted to singlet excited energy (reverse intersystem crossing). It can be generated efficiently. In addition, it is possible to generate an exciplex (exciplex) that forms an excited state with two types of substances. The exciplex (also called an exciplex or exciplex) is the S1 level and The difference with the T1 level is extremely small, and triplet excitation energy is converted to singlet excitation energy. It functions as a TADF material that can

[0075] As an index of the T1 level, the phosphorescence spectrum observed at low temperatures (e.g., 10 K) is used. TADF materials should be those that emit light at the short wavelength side of the fluorescence spectrum at room temperature or low temperatures. Draw a tangent at the tail of the graph, and the energy of the wavelength of the extrapolated line is taken as the S1 level. A tangent line was drawn at the base of the short wavelength side of the curve, and the energy of the wavelength of the extrapolated line was taken as the T1 level. In this case, it is preferable that the difference between S1 and T1 is 0.2 eV or less.

[0076] In addition, perovskite is a material that has the function of converting triplet excitation energy into luminescence. Nanostructures of transition metal compounds with perovskite structures are particularly well known. Nanostructures of bismuth oxides are preferred. Examples of such nanostructures include nanoparticles and nanorods. is preferred.

[0077] FIG. 1B is a schematic cross-sectional view illustrating a light-emitting layer 130 of a light-emitting element according to one embodiment of the present invention. In one embodiment of the invention, the light-emitting layer 130 comprises Compound 131 and Compound 132. Compound 1 has the function of converting triplet excitation energy into luminescence, and compound 132 has the function of converting singlet excitation energy into luminescence. Fluorescent materials have the function of converting energy into light. To obtain an optical element, it is preferable to use a fluorescent material as the compound 132. Compound 131 has the function of converting triplet excitation energy into luminescence, and therefore has high luminescence efficiency. In order to obtain a light-emitting element with a high conductivity, it is preferable that carrier recombination occurs in the compound 131. Therefore, the singlet excitation energy of the exciton generated by carrier recombination in compound 131 and Both triplet excited states are finally transferred to the singlet excited state of compound 132. It is preferable that the compound 132 emits light. 1 is the energy donor and compound 132 is the energy acceptor. In this case, the light-emitting layer 130 is a fluorescent compound having a compound 131 as a host material and a compound 132 as a guest material. In Figure 1(C), the host material is an energy donor, The guest material functions as an energy acceptor. The luminescence derived from the compound 132 can be obtained.

[0078] <Emitting layer configuration example 1> FIG. 1C shows one example of the correlation of energy levels in a light-emitting layer in a light-emitting element of one embodiment of the present invention. This configuration example shows a case where a TADF material is used for the compound 131.

[0079] In addition, the energy level of the compound 131 and the compound 132 in the light-emitting layer 130 is The relationship is shown in Figure 1(C). The notations and symbols in Figure 1(C) are as follows: ·Host(131): Compound 131 ·Guest(132): Compound 132 T C1 :T1 level of compound 131 ·S C1 : S1 level of compound 131 ·S G : S1 level of compound 132 T G :T1 level of compound 132

[0080] Here, we focus on the triplet excitation energy of compound 131 generated by current excitation. Compound 131 has TADF properties. Therefore, compound 131 increases the triplet excitation energy. It has the function of converting it into singlet excitation energy by photoconversion (Figure 1(C) Route A1). The singlet excitation energy of compound 131 is rapidly transferred to compound 132. (Fig. 1(C) Route A2). At this time, S C1 ≧S G That is Specifically, a tangent line is drawn at the short wavelength side of the fluorescence spectrum of Compound 131. Then, the energy of the wavelength of the extrapolated line is S C1 The absorption spectrum of compound 132 is The energy of the edge wavelength is S G When this is done, S C1 ≧S G It is preferable that:

[0081] The triplet excitation energy generated in compound 131 is converted to the acetylene compound via the above-mentioned routes A1 and A2. The energy is transferred to the S1 level of the photoresist material, compound 132, causing compound 132 to emit light. In Route A2, the compound Compound 131 functions as an energy donor, and compound 132 functions as an energy acceptor.

[0082] Here, in the light-emitting layer 130, the compound 131 and the compound 132 are mixed. Therefore, the triplet excitation energy of compound 131 is increased in competition with the above-mentioned routes A1 and A2. The process of converting the triplet excited energy of compound 132 (Fig. 1(C) Route A3) occurs. Since compound 132 is a fluorescent material, the triplet excitation energy of compound 132 is In other words, when the energy transfer of route A3 occurs, the luminous efficiency of the light-emitting element In reality, T C1 From T G The energy transfer to (route A3) is Not directly, but T of compound 132G energy transfer once to a higher triplet excited state , then by internal conversion to T G There is a possible route to this, but this process is omitted in the diagram. In the rest of this specification, the undesired thermal deactivation process, i.e., T G The deactivation process to The same is true.

[0083] Here, the Förster mechanism (dipole-dipole interaction) is used as the intermolecular energy transfer mechanism. The Dexter mechanism (electron exchange interaction) is known. Since compound 132 is a fluorescent material, the energy transfer of route A3 is Dexter Generally, the Dexter mechanism is dominant. The distance between the ion beam and the energy acceptor, compound 132, is significantly less than 1 nm. Therefore, in order to suppress route A3, the distance between the host material and the guest material, i.e., the energy It is important to keep the distance between the donor and the energy acceptor large.

[0084] In addition, the singlet excited energy level (S C1 ) from the triplet of compound 132 Excitation energy level (T G ) is the singlet ground state in compound 132. Since direct transition from the excited state to the triplet excited state is forbidden, the main energy transfer process is Since this is unlikely to occur, it is not shown in the figure.

[0085] T in Figure 1(C) G is the energy level originating from the luminophore in the energy acceptor. Therefore, in order to suppress route A3 in more detail, the energy donor It is important to increase the distance between the luminophore and the energy acceptor. As a method to increase the distance between the luminophores of the energy donor and the energy acceptor In general, it is possible to reduce the concentration of energy acceptors in the mixed film of these compounds. However, when the concentration of the energy acceptor in the mixed film is reduced, the energy Not only energy transfer from donor to energy acceptor based on the Dexter mechanism, In this case, the energy transfer based on the Förster mechanism is also suppressed. 2 is based on the Förster mechanism, which can lead to problems such as a decrease in the luminous efficiency and reliability of the light-emitting element. A problem arises.

[0086] Therefore, the inventors have developed an energy acceptor that is farther away from the energy donor. By using a fluorescent material having a protecting group for the protection, it is possible to suppress the decrease in the luminous efficiency. I discovered something.

[0087] <Concept of fluorescent materials with protecting groups> Figure 2(A) shows a typical fluorescent material without a protective group as the guest material. FIG. 2(B) shows a case where the protective layer is dispersed in a host material, and FIG. 2(C) shows a case where the protective layer is dispersed in a light-emitting element of one embodiment of the present invention. 1 shows a conceptual diagram of a case where a fluorescent material having a group is dispersed as a guest material in a host material. The host material may be interpreted as an energy donor, and the guest material as an energy acceptor. Here, the protecting group functions to increase the distance between the luminophore and the host material. In (A), the guest material 301 has a luminophore 310. The guest material 301 has an energy On the other hand, in FIG. 2(B), the guest material 302 has a luminophore 310 and a protecting group 320. In addition, in FIGS. 2(A) and 2(B), The light-emitting material 301 and the guest material 302 are surrounded by a host material 330. Since the distance between the group and the host material is short, the energy from the host material 330 to the guest material 301 As the energy transfer, the Förster mechanism (Fig. 2(A) and (B) shows the Route A4) and energy transfer via the Dexter mechanism (Route A5 in Figure 2(A) and (B)). ) can occur. Triplet excitation from the host material to the guest material by the Dexter mechanism. When the triplet excited state of the guest material is generated by the energy transfer, When the material is a fluorescent material, the triplet excitation energy is non-radiatively deactivated, resulting in a decrease in luminous efficiency. This is one of the factors.

[0088] On the other hand, in FIG. 2B, the guest material 302 has a protecting group 320. The distance between the group 310 and the host material 330 can be increased. This can suppress energy transfer (route A5).

[0089] Here, in order for the guest material 302 to emit light, the Dexter mechanism is suppressed. The resist material 302 must receive energy from the host material 330 via the Förster mechanism. In other words, it is necessary to suppress the energy transfer by the Dexter mechanism while promoting the Förster mechanism. It is preferable to efficiently utilize the energy transfer mechanism. It is known that energy transfer is also affected by the distance between the host material and the guest material. Generally, when the distance between the host material 330 and the guest material 302 is 1 nm or less, the Dexter mechanism prevails. The Förster mechanism is dominant between 1 nm and 10 nm. If the distance between the material 330 and the guest material 302 is 10 nm or more, energy transfer is unlikely to occur. The distance between the host material 330 and the guest material 302 is This can be interpreted as the distance between the two points.

[0090] Therefore, the protecting group 320 preferably extends from the luminophore 310 within a range of 1 nm to 10 nm. It is more preferable that the thickness is 1 nm or more and 5 nm or less. While suppressing the energy transfer from 30 to the guest material 302 by the Dexter mechanism, Therefore, it is possible to utilize the energy transfer by the Förster mechanism. A light-emitting element with high optical efficiency can be fabricated.

[0091] In addition, it improves the efficiency of energy transfer by the Förster mechanism (improving the energy transfer speed). In order to achieve this, the guest material 301 or the guest material 302 is However, increasing the concentration of guest material usually leads to a decrease in the dextromethorphan level. The energy transfer rate of the mechanism also increases, resulting in a decrease in luminous efficiency. It has been difficult to increase the concentration of guest materials. In the case of a fluorescent light emitting device using a functional material as a host material, the concentration of the guest material Light-emitting devices with low guest material concentrations of 1 wt% or less have been reported.

[0092] On the other hand, in a light-emitting element according to one embodiment of the present invention, a guest material having a protecting group in a light-emitting layer is used. Therefore, while suppressing the energy transfer by the Dexter mechanism, the Förster mechanism This allows for efficient use of energy transfer via the energy acceptor structure. As a result, the energy transfer by the Dexter mechanism can be increased. This paper aims to suppress energy transfer while increasing the rate of energy transfer via the Förster mechanism. This makes it possible to realize the contradictory phenomena. Increasing the concentration shortens the excited lifetime of the energy acceptor in the light-emitting layer. The reliability of the light-emitting element can be improved. , preferably 2 wt% or more and 30 wt% or less, more preferably 5 wt% or more and 20 wt% or less More preferably, the content is 5 wt % or more and 15 wt % or less. The energy transfer rate by the Wörster mechanism can be increased, resulting in emission with high luminous efficiency. Furthermore, it is possible to obtain a photonic device that has the function of converting triplet excitation energy into light emission. By using a material with high luminous efficiency equivalent to that of phosphorescent light-emitting devices, Furthermore, the luminous efficiency can be improved by using highly stable fluorescent materials. Since the concentration can be made to be high, a light-emitting element with good reliability can be manufactured. In the layer, the material that mainly emits light is the guest material, and the materials other than the guest material are the host. This is the concentration when used as a test material.

[0093] In particular, the effect of the light-emitting element of one embodiment of the present invention is that it can be obtained by simply using a highly stable fluorescent material. This is not the only effect of improving reliability. The energy transfer described above is always accompanied by degradation and defects. This competes with the quenching process caused by the pure substance, and the quenching rate constant of this quenching process increases over time. If the light emitting element is turned off, the light emitting element emits light at a reduced rate. In other words, the luminance of the light emitting element deteriorates. However, as described above, one aspect of the present invention is to suppress energy transfer by the Dexter mechanism while However, the energy transfer rate due to the Förster mechanism can be increased compared to conventional light-emitting devices. This reduces the influence of competition with the quenching process, thereby extending the life of the device.

[0094] Here, the term "luminophore" refers to an atomic group (skeleton) that causes light emission in a fluorescent material. The photophores generally have π bonds and preferably contain aromatic rings, and may be fused aromatic or fused aromatic rings. In another embodiment, the luminophore has a transition on the ring plane. It can be considered as an atomic group (skeleton) containing an aromatic ring in which a dipole vector exists. When one fluorescent material has a plurality of condensed aromatic rings or condensed heteroaromatic rings, the plurality of condensed aromatic rings The aromatic ring or fused heteroaromatic ring having the lowest S1 level is used as the luminescent material of the fluorescent material. In addition, the longest one of the plurality of condensed aromatic rings or condensed heteroaromatic rings may be considered as a group. The skeleton having an absorption edge on the wavelength side may be considered as the luminophore of the fluorescent material. The fluorescent material can be identified from the shape of the emission spectrum of each of the fused aromatic rings or fused heteroaromatic rings. In some cases, the luminophores can be predicted.

[0095] The condensed aromatic ring or condensed heteroaromatic ring includes a phenanthrene skeleton, a stilbene skeleton, an acrylonitrile skeleton, and a cyclohexylamine skeleton. Examples include lydone skeleton, phenoxazine skeleton, and phenothiazine skeleton. skeleton, anthracene skeleton, fluorene skeleton, chrysene skeleton, triphenylene skeleton, tetra Cene skeleton, pyrene skeleton, perylene skeleton, coumarin skeleton, quinacridone skeleton, naphthobisbenzyl A fluorescent material having a benzofuran skeleton is preferred because it has a high fluorescence quantum yield.

[0096] In addition, the substituents used as protecting groups have a higher T1 level than the luminophore and the host material. It is necessary to have a triplet excited energy level. Therefore, it is preferable to use a saturated hydrocarbon group. This is because the triplet excitation energy level of a substituent that does not have a π bond is high. Substituents that do not have a π bond have a low ability to transport carriers (electrons or holes). Therefore, the saturated hydrocarbon group has little effect on the excited state or carrier transport properties of the host material. The distance between the luminophore and the host material can be increased without providing a π bond. In organic compounds that simultaneously have a substituent and a substituent having a π-conjugated system, The frontier orbital {HOMO(Highest Occupied Mol ocular orbital (also called the highest occupied molecular orbital) and LUMO (Lowest Occupied Molecular Orbital) Unoccupied Molecular Orbital (also known as the lowest unoccupied molecular orbital) In many cases, the luminophores have frontier orbitals. As shown, energy transfer by the Dexter mechanism requires an energy donor and an energy accessor. The overlap of the HOMO and LUMO of the scepter is important. By using the protecting group, the frontier orbital of the host material, which is the energy donor, The distance between the path and the frontier orbitals of the guest material, which is the energy acceptor, is increased. This makes it possible to suppress energy transfer via the Dexter mechanism.

[0097] Specific examples of the protecting group include alkyl groups having 1 to 10 carbon atoms. Since the group is required to increase the distance between the luminophore and the host material, bulky substituents are preferred. Therefore, alkyl groups having 3 to 10 carbon atoms, substituted or unsubstituted alkyl groups having 3 to 10 carbon atoms, The following cycloalkyl groups and trialkylsilyl groups having 3 to 10 carbon atoms are preferably used: In particular, a bulky branched alkyl group is preferred as the alkyl group. The substituent is particularly preferably one having a quaternary carbon, since it becomes a bulky substituent.

[0098] It is also preferable that one luminophore has five or more protecting groups. The entire luminophore can be covered with a protecting group, allowing for proper adjustment of the distance between the host material and the luminophore. In addition, Figure 2(B) shows the state in which the luminophore and the protecting group are directly bonded. However, it is more preferable that the protecting group is not directly attached to the luminophore. The luminophore may be bonded to the luminophore via a divalent or higher substituent such as an arylene group or an amino group. By connecting the protecting group to the luminophore via a substituent, the distance between the luminophore and the host material can be effectively reduced. Therefore, if the luminophore and the protecting group are not directly bonded, the protecting group If there are four or more per luminophore, energy transfer via the Dexter mechanism is effective. can be suppressed.

[0099] In addition, the divalent or higher substituent linking the luminophore and the protecting group is preferably a substituent having a π-conjugated system. By adopting this structure, the physical properties of the guest material, such as the emission color, HOMO level, and glass transition point, can be controlled. The protecting groups are located on the outermost side when the molecular structure is viewed from the center of the luminophore. It is preferable to place

[0100] <Examples of fluorescent materials with protecting groups and molecular structures> Here, a compound represented by the following structural formula (102) can be used for a light-emitting element of one embodiment of the present invention. N,N'-[(2-tert-butylanthracene)-9,10- [diyl]-N,N'-bis(3,5-di-tert-butylphenyl)amine (abbreviation: 2 The structure of tBu-mmtBuDPhA2Anth) is shown below. In 2Anth, the anthracene ring is the luminophore and the tertiary butyl (tBu) group acts as a protecting group.

[0101] [ka]

[0102] The ball-and-stick model representation of the above 2tBu-mmtBuDPhA2Anth is shown in Figure 3(B). In addition, Figure 3(B) shows 2tBu-mmtBuDPhA2Anth in the direction of the arrow in Figure 3(A). This shows the appearance when viewed from the horizontal direction (horizontal to the anthracene ring plane). The shaded area represents the area directly above the anthracene ring plane, which is the luminophore. For example, in FIG. 3(B), the arrow (a The atom indicated by arrow (b) is the carbon atom of the tBu group that overlaps with the shaded area. The atom is the hydrogen atom of the tBu group that overlaps the shaded area. In uDPhA2Anth, the atoms that make up the protecting group are located directly above one side of the luminophore surface, and The atoms that make up the protecting groups are also located directly above the surface. Even when the material is dispersed in the host material, the anthracene rings, which are the luminophores, are aligned in the planar direction and The distance between the anthracene ring and the host material can be increased in both the horizontal and vertical directions. , energy transfer via the Dexter mechanism can be suppressed.

[0103] In addition, the energy transfer by the Dexter mechanism is, for example, When the transition is between the OMO and LUMO, the HOMO overlap of the host and guest materials The overlap of the HOMO and LMO of the host and guest materials is important. When UMOs overlap, the Dexter mechanism is significantly activated. Therefore, they suppress the Dexter mechanism. To achieve this, it is important to suppress the overlap of the HOMO and LUMO of both materials. In other words, it is important to increase the distance between the skeleton involved in the excited state and the host material. In fluorescent materials, both the HOMO and LUMO are often possessed by the luminophore. For example, The HOMO and LUMO of the guest material are above and below the plane of the luminophore (2tBu-mmtBuD In PhA2Anth, when the anthracene ring is extended above and below the anthracene ring, the luminescence It is important in the molecular structure that the above and below the plane of the group be covered with protecting groups.

[0104] In addition, fused aromatic and heteroaromatic rings, such as pyrene and anthracene rings, function as luminophores. The transition dipole vector of the aromatic ring lies on the ring plane. Therefore, in Figure 3(B), Bu-mmtBuDPhA2Anth is the plane where the transition dipole vector exists, i.e., An It is preferable that the protective group tBu group overlaps the area directly on the plane of the tracene ring. In the example, at least one of the atoms constituting the multiple protecting groups (tBu groups in Figures 3(A) and (B)) is One of the rings is a fused aromatic ring or a fused heteroaromatic ring (anthracene in Figure 3(A) and (B)). at least one of the atoms constituting the protecting groups is located directly on one face of the protecting group (the aryl ring) and One of them is located directly above the other face of the fused aromatic ring or fused heteroaromatic ring. By this, even if the guest material is dispersed in the host material, the luminophore and the host material This allows the distance between the two molecules to be increased, suppressing the energy transfer caused by the Dexter mechanism. In addition, a protecting group such as a tBu group is placed to cover a luminophore such as an anthracene ring. It is preferable that

[0105] <Emitting layer configuration example 2> FIG. 4C shows the energy levels in the light-emitting layer 130 of the light-emitting element 150 of one embodiment of the present invention. The light-emitting layer 130 shown in FIG. 4(A) is composed of a compound 131 and a compound 132. and further compound 133. In one embodiment of the present invention, compound 132 is a fluorescent In this example, the compound 131 and the compound 133 are exciplexes. It is a combination that forms.

[0106] The combination of Compound 131 and Compound 133 is a combination capable of forming an exciplex. However, one of them is a compound that has the function of transporting holes (hole transport property). and the other is a compound having a function of transporting electrons (electron transport property). In this case, it becomes easier to form donor-acceptor type exciplexes, and the exciplexes are efficiently formed. In addition, the combination of Compound 131 and Compound 133 can form a hole transport When a compound having electron transport properties is used in combination with a compound having electron transport properties, the mixing ratio This makes it possible to easily control the carrier balance. The compound having the property of electron transporting and the compound having the property of electron transporting are preferably in the range of 1:9 to 9:1 (weight ratio). Moreover, by having this configuration, it is possible to easily control the carrier balance. Therefore, the carrier recombination region can be easily controlled.

[0107] In addition, as a combination of host materials that efficiently form exciplexes, Compound 131 and The HOMO level of one of the compounds 133 and 134 is higher than that of the other, and one of the LUMO levels It is preferable that the HOMO level of compound 131 is higher than the other LUMO level. The HOMO level of compound 133 is equal to that of compound 131, or the LUMO level of compound 131 is equal to that of compound 1. The LUMO level may be equivalent to that of 33.

[0108] The LUMO and HOMO levels of the compounds were determined by cyclic voltammetry (C V) Derived from the electrochemical properties (reduction potential and oxidation potential) of the compound measured by the measurement It is possible.

[0109] For example, when compound 131 has hole transport properties and compound 133 has electron transport properties, As shown in the energy band diagram in Figure 4(B), the HOMO level of compound 131 is The HOMO level of compound 131 is preferably higher than the HOMO level of compound 33. It is preferable that the LUMO level is higher than that of 3. The electron holes and electrons are carriers injected from a pair of electrodes (electrodes 101 and 102). This is preferable because electrons are easily injected into compound 131 and compound 133, respectively.

[0110] In FIG. 4(B), Comp(131) represents compound 131, and Comp(1 33) represents compound 133, and ΔE C1 are the LUMO and HOMO levels of compound 131. represents the energy difference between the C3 is the energy difference between the LUMO and HOMO levels of compound 132. represents the energy difference, and ΔE E is the LUMO level of compound 133 and the HOMO level of compound 131. The notation and symbol represent the energy difference between

[0111] In addition, the exciplex formed by Compound 131 and Compound 133 has a HOMO and compound 133 becomes an exciplex having a LUMO molecular orbital. The excitation energy of the exciplex is the LUMO level of compound 133 and the HOMO level of compound 131. The energy difference between the levels (ΔE E ) and the LUMO and HOMO levels of compound 131 are The energy difference between the levels (ΔE C1 ) and the relationship between the LUMO level and the HOMO level of compound 133 Energy difference (ΔE C3 ) is smaller than Compound 131 and Compound 133. By forming an exciplex with In addition, since the excitation energy is lower, the exciplex has a stable excited state. It can be formed.

[0112] In addition, the compounds 131, 132, and 133 in the light-emitting layer 130 The correlation between the energy levels is shown in Figure 4(C). The notations and symbols in Figure 4(C) are as follows: As shown below. ·Comp(131): Compound 131 ·Comp(133): Compound 133 ·Guest(132): Compound 132 ·S C1 : S1 level of compound 131 T C1 :T1 level of compound 131 ·S C3 : S1 level of compound 133 T C3 : S1 level of compound 133 T G :T1 level of compound 132 ·SE : S1 level of the exciplex T E :T1 level of exciplex

[0113] In the light-emitting element of one embodiment of the present invention, the light-emitting layer 130 contains Compound 131 and Compound 1 33 forms an exciplex. The S1 level of the exciplex (S E ) and the T1 level of the exciplex (T E ) are adjacent energy levels (see route A6 in Figure 4(C)).

[0114] Excitation energy levels of exciplexes (S E and T E ) is the compound that forms the exciplex. The S1 level (S C1 and S C3 ) is lower than It is possible to form an excited state with lower excitation energy. The driving voltage of the element 150 can be reduced.

[0115] The S1 level of the exciplex (S E ) and T1 level (T E ) are adjacent energy levels Therefore, the exciplex is prone to reverse intersystem crossing and has TADF properties. It has the function of converting energy into singlet excitation energy by upconversion. (Fig. 4(C) Route A7). The singlet excitation energy of the exciplex is rapidly converted into (Fig. 4(C) Route A8). At this time, S E ≧S G In Route A8, the exciplex is the energy donor, and the compound 132 acts as an energy acceptor. Specifically, the fluorescence spectrum of the exciplex Draw a tangent line at the short wavelength side of the curve, and let the wavelength energy of the extrapolated line be S E Then, compound The energy of the wavelength at the absorption edge of the absorption spectrum of substance 132 is S. G When this is done, S E ≧S G in It is preferable that there is.

[0116] To enhance the TADF properties, the T1 levels of both Compound 131 and Compound 133, Nawachi T C1 and T C3 But, T E It is preferable that the value is equal to or greater than 1. The emission peak wavelengths on the shortest wavelength side of the phosphorescence spectra of Compounds 131 and 133 are It is preferable that the wavelength of each of the exciplexes is equal to or shorter than the maximum emission peak wavelength. Draw a tangent line at the short wavelength side of the optical spectrum, and define the wavelength energy of the extrapolated line as S E The phosphorescence spectra of Compound 131 and Compound 133 are connected at the short wavelength side. The energy of the wavelength of the extrapolated lines is calculated as the T of each compound. C1 and T C3 When To, S E -T C1 ≦0.2 eV and S E -T C3 Preferably ≦0.2 eV .

[0117] The triplet excitation energy generated in the light-emitting layer 130 is transferred to the S1 level of the exciplex via the route A6. The energy transfer from the ion to the S1 level of the guest material (route A8) Therefore, the light-emitting layer 130 contains a combination of materials that form an exciplex. By using such a compound, the luminous efficiency of the fluorescent light emitting element can be increased.

[0118] In the light-emitting element of one embodiment of the present invention, Compound 132 contains a luminophore having a protecting group. By using this material, as described above, the dexterity expressed by the route A9 can be obtained. This suppresses energy transfer via the - mechanism and prevents the deactivation of triplet excitation energy. Therefore, a fluorescent light emitting device with high luminous efficiency can be obtained.

[0119] The above-described processes of routes A6 to A8 are referred to as ExSET (Exci plex-Singlet Energy Transfer) or ExEF(Exc It is sometimes called "plex-enhanced fluorescence." In other words, the light-emitting layer 130 transfers excitation energy from the exciplex to the fluorescent material.

[0120] <Emitting layer configuration example 3> In this configuration example, a phosphorescent material is used as the compound 133 of the light-emitting element using the above-mentioned ExEF. In other words, a phosphorescent material is used in one of the compounds forming an exciplex. The case where the above formula is used will be explained.

[0121] In this example, a compound having a heavy atom is used as one of the compounds forming the exciplex. Therefore, intersystem crossing between the singlet and triplet states is promoted. to form an exciplex that can transition from the nucleus to the singlet ground state (i.e., can exhibit phosphorescence). In this case, unlike ordinary exciplexes, the triplet excited energy of the exciplex is Energy level (T E ) is the energy donor level, so T E is a compound in which the compound is a light-emitting material The singlet excited energy level of 132 (S G ) or more. A tangent line is drawn at the short wavelength side of the emission spectrum of an exciplex using atoms, and the extrapolated line is The energy of the wavelength T E The energy of the wavelength of the absorption edge of the absorption spectrum of compound 132 is Ghee S G When this is done, T E ≧S G It is preferable that:

[0122] By using such a correlation of energy levels, the triplet excitation energy of the generated exciplex can be calculated. The triplet excited energy level (T E ) to the singlet excited energy of compound 132. Energy level (S G ) energy can be transferred to the S1 level (S E ) and T1 level (T E ) are adjacent energy levels, so the emission spectrum In some cases, it is difficult to clearly distinguish between fluorescence and phosphorescence. It may be possible to distinguish between fluorescence or phosphorescence by

[0123] The phosphorescent material used in the above configuration contains heavy atoms such as Ir, Pt, Os, Ru, and Pd. On the other hand, in this configuration example, the phosphorescent material acts as an energy donor. Therefore, the quantum yield can be either high or low. Allowed transitions are those in which energy transfer from the singlet excited energy level of the guest material to the singlet excited energy level of the guest material occurs. It is desirable to use the above-mentioned exciplexes composed of phosphorescent materials and guest molecules from phosphorescent materials. Energy transfer to the material occurs from the triplet excited energy level of the energy donor to the guest material. The energy transfer to the singlet excited energy level of the material (energy acceptor) is allowed Therefore, the excitation is not performed through the process of route A7 in FIG. The triplet excitation energy of the complex is converted to the S1 level (S G ) In other words, the guest material can be transferred to the Triplet and singlet excitation energy can be transferred to the S1 level of the material. Route A8 In the formula, the exciplex is the energy donor and compound 132 is the energy acceptor. It functions as:

[0124] In the light-emitting element of one embodiment of the present invention, Compound 132 contains a luminophore having a protecting group. By using this material, as described above, the dexterity expressed by the route A9 can be obtained. This suppresses energy transfer via the - mechanism and prevents the deactivation of triplet excitation energy. Therefore, a fluorescent light emitting device with high luminous efficiency can be obtained.

[0125] <Emitting layer configuration example 4> In this configuration example, the compound 133 of the light-emitting device using the above-mentioned ExEF has TADF properties. The case where such a material is used will be described with reference to FIG. 4(D).

[0126] Since compound 133 is a TADF material, compound 133 that does not form an exciplex is a trivalent A mechanism for converting doublet excitation energy into singlet excitation energy by upconversion (Fig. 4(D) Route A 10 The singlet excitation energy of compound 133 is can be rapidly transferred to compound 132 (Figure 4(D) Route A 11 ).child When S C3 ≧S G It is preferable that:

[0127] As in the previous structural example of the light-emitting layer, in the light-emitting element of one embodiment of the present invention, the route A in FIG. Triplet excitation energy is transferred to the guest material, compound 132, via route A6 or route A8. Route A in Figure 4(D) 10 and Route A 11 Transfer to compound 132 via There are multiple pathways for triplet excitation energy to be transferred to fluorescent materials. In Route A8, the exciplex releases the energy The donor is 132, and the compound 132 acts as the energy acceptor. 11 In this case, compound 133 is the energy donor and compound 132 is the energy acceptor. It functions as a target.

[0128] In this example, the exciplex and compound 133 are energy donors, and compound 132 acts as an energy acceptor.

[0129] <Emitting layer configuration example 5> FIG. 5(A) shows a case where four kinds of materials are used for the light-emitting layer 130. In the light-emitting layer 130, Compound 131, Compound 132, Compound 133, and Compound 134 are In one embodiment of the present invention, compound 133 converts triplet excitation energy into luminescence. In this example, the compound 133 is a phosphorescent material. Compound 132 is a guest material that exhibits fluorescent emission. It is an organic compound that forms an exciplex with 134.

[0130] In addition, the compound 131, the compound 132, the compound 133, and the compound The correlation of the energy levels of the substance 134 is shown in FIG. 5(B). The symbols and notations are as follows, and the other symbols and notations are the same as those shown in FIG. 4(B). The same is true. ·S C4 : S1 level of compound 134 T C4 : T1 level of compound 134

[0131] In the light-emitting element of one embodiment of the present invention shown in this configuration example, the compound contained in the light-emitting layer 130 The compound 131 and compound 134 form an exciplex. The S1 level of the exciplex (S E ) and exciplexes T1 level (T E ) are adjacent energy levels (Figure 5(B) Route A 12 reference).

[0132] The exciplexes generated by the above process lose their excitation energy, as mentioned above. The two substances that formed the exciplex then behave as separate substances again.

[0133] Excitation energy levels of exciplexes (S E and T E ) is the compound that forms the exciplex. The S1 level (S C1 and S C4 ) is lower than It is possible to form an excited state with lower excitation energy. The driving voltage of the element 150 can be reduced.

[0134] Here, compound 133 is a phosphorescent material, and intersystem crossing between the singlet and triplet states is Therefore, the singlet excitation energy and triplet excitation energy of the exciplex are Both glycerol and glycerol rapidly transfer to compound 133 (Route A)13 ). At this time, T E ≧T C3 In addition, it is preferable that the triplet excitation energy of Compound 133 is efficiently converted into The singlet excitation energy of compound 132 can be converted to the 14 ). where ,As shown in Figure 5(B), T E ≧T C3 ≧S G Then, the excitation energy of compound 133 is This allows efficient transfer of the singlet excitation energy to the guest material, compound 132. Specifically, a tangent line is drawn at the short wavelength side of the phosphorescence spectrum of Compound 133. Then, the energy of the wavelength of the extrapolated line is T C3 The absorption spectrum of compound 132 is The energy of the edge wavelength is S G When this is done, T C3 ≧S G Route A is preferred. 14 In this case, compound 133 is the energy donor and compound 132 is the energy acceptor. It functions as a

[0135] In this case, the combination of Compound 131 and Compound 134 can form an exciplex. Any possible combination is acceptable, but one of them is a compound having hole transport properties and the other is an electron More preferably, the compound has transport properties.

[0136] In addition, as a combination of materials that efficiently form an exciplex, Compound 131 and Compound 132 are One HOMO level of the compound 134 is higher than the other HOMO level, and one LUMO level is preferably higher than the other LUMO level.

[0137] The correlation between the energy levels of compounds 131 and 134 is not limited to that shown in FIG. 5(B). That is, the singlet excited energy level (S C1 ) is compound 13 The singlet excited energy level of 4 (S C4 ) may be higher or lower than that of Compound 13. The triplet excited energy level of 1 (T C1 ) is the triplet excited energy level of compound 134 (T C4 ) may be higher or lower.

[0138] In the light-emitting element of one embodiment of the present invention, Compound 131 has a π-electron-deficient skeleton. This is preferable. By adopting this structure, the LUMO level of the compound 131 is lowered, and the exciplex It is good for shaping the body.

[0139] In the light-emitting element according to one embodiment of the present invention, Compound 131 has a π-electron-rich skeleton. This is preferable. By adopting this structure, the HOMO level of the compound 131 becomes high, and the exciplex It is good for shaping the body.

[0140] In the light-emitting element of one embodiment of the present invention, Compound 132 contains a luminophore having a protecting group. By using this structure, as described above, Route A 15 Dex represented by This suppresses the energy transfer via the electron transport mechanism and the deactivation of triplet excitation energy. Therefore, a fluorescent light emitting device with high luminous efficiency can be obtained. The concentration of the donor compound 133 can be increased, resulting in the Dexter mechanism By suppressing the energy transfer by the ion beam and increasing the energy transfer rate by the Förster mechanism, This makes it possible to realize two contradictory phenomena: the energy transfer by the Förster mechanism By increasing the transfer rate, the excited lifetime of the energy acceptor in the emitting layer is shortened. Therefore, the reliability of the light-emitting element can be improved. When 133 is added to the light-emitting layer, its concentration is 2 wt% or more and 50 wt% or less relative to the host material. % or less, more preferably 5 wt% to 30 wt%, and even more preferably 5 By using this composition, the Förster mechanism Since the energy transfer rate can be increased, a light-emitting element with high luminous efficiency can be obtained. Cut.

[0141] In addition, Route A shown above 12 and A 13 This process is referred to as ExTET (E It is sometimes called xciplex-Triplet Energy Transfer In other words, the light-emitting layer 130 functions to transfer excitation energy from the exciplex to the compound 133. Therefore, in this configuration example, a fluorescent compound having a protecting group in the light-emitting layer that can utilize ExTET is used. It can be said that the material is mixed.

[0142] <Emitting layer configuration example 6> In this configuration example, a material having TADF properties is added to Compound 134 described in Configuration Example 5 of the light-emitting layer. This section explains the case where a fee is used.

[0143] FIG. 5(C) shows the case where four kinds of materials are used for the light-emitting layer 130. In the light-emitting layer 130, Compound 131, Compound 132, Compound 133, and Compound 134 are In one embodiment of the present invention, compound 133 is capable of converting triplet excitation energy into luminescence. Compound 132 is a guest material that exhibits fluorescent emission. 131 is an organic compound that forms an exciplex with compound 134.

[0144] Here, compound 134 is a TADF material, so compound 13 does not form an exciplex. 4 converts triplet excitation energy to singlet excitation energy by upconversion. (Fig. 5(C) Route A 16 The singlet excited electrons in compound 134 The energy can be rapidly transferred to compound 132 (Figure 5(C) Route A1 7). At this time, S C4 ≧S G Specifically, the fluorescent spectrum of Compound 134 is Draw a tangent line at the short wavelength side of the curve, and let the wavelength energy of the extrapolated line be S C4 year , where S is the energy of the wavelength at the absorption edge of the absorption spectrum of compound 132. G When this is done, S C4 ≧S G It is preferable that:

[0145] As in the previous structural example of the light-emitting layer, in the light-emitting element of one embodiment of the present invention, the route A in FIG. 12 Route A 14 The triplet excitation energy is transferred to the guest material, compound 132. The route to travel and Route A in Figure 5(C) 16 and Route A 17 Transferred to compound 132 via There are multiple pathways for triplet excitation energy to transfer to fluorescent materials. By doing so, the luminous efficiency can be further improved. 14 In the compound 133 Compound 132 acts as an energy acceptor. Part A 17In this case, compound 134 is the energy donor and compound 132 is the energy accessor. Acts as a scepter.

[0146] <Emitting Layer Configuration Example 7> FIG. 6B shows the energy levels in the light-emitting layer 130 of the light-emitting element 150 of one embodiment of the present invention. The light-emitting layer 130 shown in FIG. 6(A) is composed of a compound 131 and a compound 132. and further compound 133. In one embodiment of the invention, compound 132 is Compound 133 is a fluorescent material that converts triplet excitation energy into luminescence. In this example, the compound 133 is a phosphorescent material. do.

[0147] The notations and symbols in FIG. 6(B) and FIG. 6(C) described later are as follows. ·Comp(131): Compound 131 ·Comp(133): Compound 133 ·Guest(132): Compound 132 ·S C1 : S1 level of compound 131 T C1 :T1 level of compound 131 T C3 :T1 level of compound 133 T G :T1 level of compound 132 ·S G : S1 level of compound 132

[0148] In the light-emitting element of one embodiment of the present invention, the compound 131 contained in the light-emitting layer 130 is mainly Recombination of carriers occurs as a result of the formation of singlet excitons and triplet excitons. Here, compound 133 is a phosphorescent material, so T C3 ≦T C1 Select materials that satisfy the following relationship: By this, both the singlet and triplet excitation energies generated in compound 131 are transferred to compound 133. T C3 (Fig. 6(B) Route A 18 ). In addition, some carriers can be recombined with compound 133.

[0149] The phosphorescent material used in the above configuration contains heavy atoms such as Ir, Pt, Os, Ru, and Pd. On the other hand, as described above, in this configuration example, the phosphorescent material is preferably an energy Since it acts as a donor, the quantum yield can be either high or low. 133, the triplet excited energy level of the energy donor is converted to the guest material. (energy acceptor) to the singlet excited energy level is an allowed transition Therefore, the triplet excitation energy of compound 133 is calculated by route A. 19 past The S1 level (S G ) can be moved to Route A. 19 To In this case, compound 133 acts as an energy donor and compound 132 acts as an energy acceptor. It works. In this case, T C3 ≧S G In this case, the excitation energy of compound 133 is efficiently This is preferable because it transfers to the singlet excited state of the guest material, compound 132. Specifically, Draw a tangent line at the short wavelength side of the phosphorescence spectrum of compound 133, and calculate the wavelength of the extrapolated line. Energy to T C3 The energy of the wavelength at the absorption edge of the absorption spectrum of compound 132 is S G When this is done, T C3 ≧S G It is preferable that:

[0150] In the light-emitting element of one embodiment of the present invention, Compound 132 contains a luminophore having a protecting group. By using this structure, as described above, Route A 20 Dex represented by This suppresses the energy transfer via the electron transport mechanism and the deactivation of triplet excitation energy. Therefore, a fluorescent light emitting device with high luminous efficiency can be obtained.

[0151] <Emitting Layer Configuration Example 8> FIG. 6C shows the energy levels in the light-emitting layer 130 of the light-emitting element 150 of one embodiment of the present invention. The light-emitting layer 130 shown in FIG. 6C is composed of a compound 131 and a compound 132. and further compound 133. In one embodiment of the invention, compound 132 is Compound 133 is a fluorescent material that converts triplet excitation energy into luminescence. In this example, when compound 133 is a compound having TADF properties, This section explains the case.

[0152] The notations and symbols in FIG. 6(C) are as follows, and the other notations and symbols are as in FIG. The notation and symbols are the same as those shown in B). ·S C3 : S1 level of compound 133

[0153] In the light-emitting element of one embodiment of the present invention, the compound 131 contained in the light-emitting layer 130 is mainly Recombination of carriers occurs as a result of the formation of singlet excitons and triplet excitons. Here, S C3 ≦S C1 KatsuT C3 ≦T C1 By selecting materials with this relationship, Compound 1 Both the singlet and triplet excitation energies generated in 31 were converted to S of compound 133. C 3 and TC3 (Fig. 6(C) Route A 21 ). In addition, some The carrier can recombine with compound 133.

[0154] Here, compound 134 is a TADF material, so it upconverts triplet excitation energy. It has the function of converting it into singlet excitation energy by the reaction (Figure 6(C) Route A 22 ) In addition, the singlet excitation energy of compound 133 is rapidly transferred to compound 132. (Fig. 6(C) Route A 23 ). At this time, S C3 ≧S G is Specifically, it is preferable to set the tangent at the tail on the short wavelength side of the fluorescence spectrum of Compound 133. The energy of the wavelength of the extrapolated line is S C3 The absorption spectrum of compound 132 is The energy of the wavelength at the convergence point is S G When this is done, S C3 ≧S G It is preferable that the root A 21 Route A 23 Through this process, the triplet excitation energy in the light-emitting layer 130 This can be converted to the fluorescence of compound 132. Route A 23 In the compound 133 acts as an energy donor, and compound 132 acts as an energy acceptor.

[0155] In the light-emitting element of one embodiment of the present invention, Compound 132 contains a luminophore having a protecting group. By using this structure, as described above, Route A 24 Dex represented by This suppresses the energy transfer via the electron transport mechanism and the deactivation of triplet excitation energy. Therefore, a fluorescent light emitting device with high luminous efficiency can be obtained.

[0156] <Energy transfer mechanism> Here, we will explain the Förster mechanism and the Dexter mechanism. Regarding the transfer of excitation energy from a first material in a ground state to a second material in a ground state, The energy transfer process between the molecules of one material and the second material is explained. The same is true for exciplexes.

[0157] <Förster mechanism> In the Förster mechanism, energy transfer does not require direct contact between molecules. Energy transfer occurs through the resonance phenomenon of the dipole vibration of a material and a second material. The first material transfers energy to the second material through the vibrational resonance phenomenon, and the first material is in an excited state. The first material is in the ground state, and the second material in the ground state is in the excited state. rate constant k of the mechanism h*→g is shown in Equation (1).

[0158]

number

[0159] In formula (1), ν represents the frequency, and f' h (ν) is the normalized value of the first material The emission spectrum (or the fluorescence spectrum when discussing energy transfer from the singlet excited state) , and phosphorescence spectrum when discussing energy transfer from triplet excited states), and ε g ( ν) represents the molar extinction coefficient of the second material, N represents Avogadro's number, and n represents the refractive index of the medium. represents the refractive index, R represents the intermolecular distance between the first and second materials, and τ represents the measured excitation represents the lifetime of the state (fluorescence lifetime or phosphorescence lifetime), c represents the speed of light, and φ represents the luminescence quantum yield ( When discussing energy transfer from a singlet excited state, the fluorescence quantum yield is used. When discussing energy transfer from a triplet excited state, the fluorescence quantum yield is used. When discussing energy transfer, it represents the phosphorescence quantum yield, and K 2 is the first material and the second material is a coefficient (0 to 4) that represents the orientation of the transition dipole moment of the The match is K 2 =2 / 3.

[0160] Here, when the energy donor is the first material and the energy acceptor is the second material, In this case, if the emission colors of the first material and the second material are similar, then f' h (ν) and and ε g (ν) overlap becomes smaller (ε g (ν) is longer than the emission spectrum of the second material. wavelength side), so k h*→g However, the light emission of one embodiment of the present invention In the device, as described above, the concentration of the energy donor in the light-emitting layer can be increased. Therefore, the value of R in formula (1) can be increased, and k h*→g It is possible to suppress the decline of Therefore, the light-emitting element of one embodiment of the present invention has an emission color close to that of the energy donor. A fluorescent material can be used as a light-emitting material. It can be used even if the emission colors of the energy donor and energy acceptor are different. .

[0161] Dexter Mechanism In the Dexter mechanism, the first and second materials overlap at the effective contact distance. approaching each other through the exchange of electrons from the first material in the excited state with those from the second material in the ground state. Energy transfer occurs. The rate constant of the Dexter mechanism is k h*→g is shown in equation (2). vinegar.

[0162]

number

[0163] In equation (2), h is Planck's constant, and K is a constant with the dimension of energy. where ν represents the frequency and f' h (ν) is the normalized emission spectrum of the first material (When discussing energy transfer from the singlet excited state, the fluorescence spectrum is used. When discussing energy transfer from the triplet excited state, the When discussing energy transfer from the fluorine-containing state, it represents the phosphorescence spectrum, and ε' represents the g (ν) is the second represents the normalized absorption spectrum of the material, L represents the effective molecular radius, and R represents the first It represents the intermolecular distance between a material and a second material.

[0164] Here, the energy transfer efficiency φ from the first material to the second material is ET is expressed as formula (3). k r First, we discuss the luminescence process of the material (energy transfer from the singlet excited state). The rate constants are expressed as follows: fluorescence when discussing the energy transfer from the triplet excited state, and phosphorescence when discussing the energy transfer from the triplet excited state. s, k n represents the rate constant of non-radiative processes (thermal deactivation and intersystem crossing) in the second material, and τ is the actual represents the lifetime of the excited state of the first material to be measured.

[0165]

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[0166] From equation (3), the energy transfer efficiency φ ET To increase the energy transfer rate, Degree constant k h*→g By increasing the rate constant k r +k n (=1 / τ) is relatively You know the smaller the better.

[0167] <Concept for enhancing energy transfer> First, consider the energy transfer via the Förster mechanism. Substituting equation (1) into equation (3), we get Therefore, in the case of the Förster mechanism, the energy Energy transfer efficiency φ ET is independent of the lifetime τ of the excited state of the first material. Movement efficiency φ ET It can be said that a higher luminescence quantum yield φ is better.

[0168] The emission spectrum of the first material and the absorption spectrum of the second material (from the singlet ground state) It is preferable that the overlap with the absorption corresponding to the transition from the excited state to the singlet state is large. It is also preferable that the molar absorption coefficient of the second material is high. This means that the absorption band of the first material overlaps with the absorption band of the second material that appears on the longest wavelength side. Since the direct transition from the singlet ground state to the triplet excited state is forbidden in the material of In the second material, the molar absorption coefficient associated with the triplet excited state is negligible. Therefore, triplet excitation from the excited state of the first material to the second material by the Förster mechanism The energy transfer process to the singlet excited state of the second material is negligible. Only the dynamic process needs to be considered.

[0169] In addition, the energy transfer rate by the Förster mechanism is calculated from the formula (1) as follows: It is inversely proportional to the sixth power of the intermolecular distance R of the material. Therefore, the energy transfer by the Dexter mechanism is dominant. In order to suppress the energy transfer and increase the energy transfer rate by the Förster mechanism, The interatomic distance is preferably 1 nm or more and 10 nm or less. Therefore, the above-mentioned protecting groups are not too bulky. Therefore, the number of carbon atoms constituting the protecting group is preferably 3 or more and 10 or less.

[0170] Next, consider the energy transfer via the Dexter mechanism. According to equation (2), the rate constant is k h*→g To increase the emission spectrum of the first material (energy from the singlet excited state), When discussing energy transfer, consider the fluorescence spectrum and energy transfer from triplet excited states. the phosphorescence spectrum in the case of the first material) and the absorption spectrum (singlet ground state to singlet excited state It can be seen that the larger the overlap with the absorption corresponding to the transition to the state, the better. The optimization of energy transfer efficiency is achieved by matching the emission spectrum of the first material with the longest wavelength of the second material. This is realized by overlapping with the absorption band appearing on the long side.

[0171] Furthermore, substituting equation (2) into equation (3) gives the energy transfer in the Dexter mechanism: Efficiency φ ET It can be seen that depends on τ. The Dexter mechanism is an energy mechanism based on electron exchange. Since it is a quantum transfer process, the singlet excited state of the first material is transferred to the singlet excited state of the second material. Similarly, the energy transfer from the triplet excited state of the first material to the triplet excited state of the second material Energy transfer to the state also occurs.

[0172] In the light-emitting element of one embodiment of the present invention, the second material is a fluorescent material. It is preferable that the efficiency of energy transfer to the triplet excited state of the first material is low. It is preferable that the efficiency of energy transfer from the first material to the second material based on the Dexter mechanism is low. The efficiency of energy transfer from the first material to the second material based on the Förster mechanism is high. It is preferable that:

[0173] As already mentioned, the efficiency of energy transfer in the Förster mechanism is On the other hand, the energy transfer efficiency in the Dexter mechanism is depends on the excitation lifetime τ of the first material and reduces the energy transfer efficiency in the Dexter mechanism. In order to lower the excitation lifetime τ of the first material, it is preferable that the excitation lifetime τ of the first material is short.

[0174] Therefore, one embodiment of the present invention uses an exciplex, a phosphorescent material, or a TADF material as the first material. These materials have the function of converting triplet excitation energy into luminescence. The efficiency of the energy transfer in the electron donor mechanism depends on the luminescence quantum yield of the energy donor. The triplet excited state can be converted to light emission, such as in photoactive materials, exciplexes, or TADF materials. The first material transfers its excitation energy to the second material via the Förster mechanism. On the other hand, according to the configuration of one embodiment of the present invention, the first material (exciplex or TADF promotes reverse intersystem crossing from the triplet excited state of the first material to the singlet excited state of the second material, The excited lifetime τ of the doublet excited state can be shortened. The transition from the triplet excited state of the exciplex (using a phosphorescent material) to the singlet ground state is promoted. As a result, the excited lifetime τ of the triplet excited state of the first material can be shortened. Dextermination of the triplet excited state of the first material to the triplet excited state of the fluorescent material (second material) This can reduce the efficiency of energy transfer in the mechanism.

[0175] In addition, in the light-emitting element of one embodiment of the present invention, as described above, the second material may include a compound having a protecting group. A fluorescent material is used. Therefore, the intermolecular distance between the first material and the second material is increased. Therefore, in the light-emitting element of one embodiment of the present invention, the first material has triplet excitation energy The second material is a fluorescent material having a protecting group. By doing so, the efficiency of energy transfer via the Dexter mechanism can be reduced. As a result, non-radiative deactivation of triplet excitation energy in the light-emitting layer 130 can be suppressed. In this way, a light-emitting element with high luminous efficiency can be provided.

[0176] <Material> Next, components of a light-emitting element according to one embodiment of the present invention will be described in detail below.

[0177] <Light-emitting layer> The materials that can be used for the light-emitting layer 130 are described below. The light-emitting layer of one embodiment of the light-emitting element includes an element having a function of converting triplet excitation energy into light emission. It uses an energy acceptor and an energy donor with a luminophore and a protecting group. Materials that have the function of converting excitation energy into light include TADF materials and exciplexes. and phosphorescent materials.

[0178] The compound 132 that functions as an energy acceptor has a luminophore, for example, a fluorophore. Phenanthrene skeleton, stilbene skeleton, acridone skeleton, phenoxazine skeleton, phenothiazine skeleton In particular, naphthalene skeleton, anthracene skeleton, fluorene skeleton, chlorine skeleton, etc. Ricenes, triphenylenes, tetracenes, pyrenes, perylenes, kumaris Fluorescent materials with a benzofuran skeleton, quinacridone skeleton, or naphthobisbenzofuran skeleton have high fluorescence quantum yield. This is preferred because of the high yield.

[0179] In addition, the protecting group may be an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, or a cycloalkyl group having 1 to 10 carbon atoms. alkyl groups, branched alkyl groups having 3 to 10 carbon atoms, trialkyl groups having 3 to 12 carbon atoms Alkylsilyl groups are preferred.

[0180] Examples of alkyl groups having 1 to 10 carbon atoms include methyl, ethyl, propyl, and pentyl groups. Examples include a branched alkyl group having 3 to 10 carbon atoms, which will be described later. The alkyl group is particularly preferred. However, the alkyl group is not limited to these.

[0181] Examples of the cycloalkyl group having 3 to 10 carbon atoms include a cyclopropyl group and a cyclobutyl group. , cyclohexyl group, norbornyl group, adamantyl group, etc. In addition, when the cycloalkyl group has a substituent, the substituent Examples include methyl, ethyl, propyl, isopropyl, butyl, and isobutyl groups. A group with one or more carbon atoms, such as a sec-butyl group, a tert-butyl group, a pentyl group, or a hexyl group Alkyl groups with 7 or less carbon atoms, cyclopentyl groups, cyclohexyl groups, cycloheptyl groups, 8, a cycloalkyl group having 5 to 7 carbon atoms, such as a 9,10-trinorbornanyl group; Aryl groups having 6 to 12 carbon atoms, such as phenyl, naphthyl, and biphenyl groups, Examples include:

[0182] Examples of branched alkyl groups having 3 to 10 carbon atoms include isopropyl and sec-butyl groups. , isobutyl group, tert-butyl group, isopentyl group, sec-pentyl group, tert -pentyl group, neopentyl group, isohexyl group, 3-methylpentyl group, 2-methylpentyl group butyl group, 2-ethylbutyl group, 1,2-dimethylbutyl group, 2,3-dimethylbutyl group The branched chain alkyl group is not limited to these.

[0183] Examples of the trialkylsilyl group having 3 to 12 carbon atoms include a trimethylsilyl group, a triethylsilyl group, and a methylsilyl group. Examples of the trialkylsilyl include a tert-butyldimethylsilyl group and a trialkylsilyl group. The groups are not limited to these.

[0184] The molecular structure of the energy acceptor is a combination of a luminophore and two or more diaryla groups. Each of the aryl groups of the diarylamino group has at least one It is preferable that each of the aryl groups has at least two protecting groups. It is more preferable that the number of protecting groups is larger. This is because the effect of suppressing energy transfer by the Dexter mechanism is large in this case. In order to suppress the increase in molecular weight and maintain sublimability, the diarylamino group is a diphenylamino group. It is preferable that the luminophore and the diarylamino group are A structure having a bond at the nitrogen atom is preferred.

[0185] In addition, the emission color can be adjusted by attaching two or more diarylamino groups to the luminophore. A fluorescent material with a high quantum yield can be obtained while maintaining the same. It is preferable to bond the luminophore to a symmetric position. The fluorescent material may have a high yield.

[0186] In addition, instead of directly introducing a protecting group into the luminophore, the aryl group of the diarylamino group is A protecting group may be introduced via a group. Since the groups can be arranged, the distance between the host material and the luminophore can be increased from any direction. In addition, when the protecting group is not directly bonded to the luminophore, the protecting group is preferably It is preferable to introduce four or more per one luminophore.

[0187] As shown in FIG. 3, at least one of the atoms constituting the multiple protecting groups is a luminophore. That is, the fused aromatic ring or the fused heteroaromatic ring is located directly on one side thereof, and a plurality of protecting groups are At least one of the atoms constituting the fused aromatic ring or the fused heteroaromatic ring is on the other side of the fused aromatic ring or the heteroaromatic ring. A configuration in which the sensor is positioned directly above the sensor is preferable. Specific examples of this configuration include the following: That is, the luminophore, fused aromatic ring or fused heteroaromatic ring, is a compound having two or more diphenyl and the phenyl groups in the two or more diphenylamino groups are each independently It has protecting groups at the 3 and 5 positions.

[0188] By adopting such a structure, as shown in FIG. 3, the 3- or 5-position of the phenyl group can be The steric configuration in which the protecting group is located directly above the condensed aromatic ring or condensed heteroaromatic ring that is the luminophore is As a result, the fused aromatic ring or the fused heteroaromatic ring can be arranged above and below the plane of the ring. This effectively covers the surface of the material, suppressing the energy transfer caused by the Dexter mechanism. do.

[0189] The energy acceptor material as described above includes a compound represented by the following general formula (G1) or ( G2) can be suitably used.

[0190] [ka]

[0191] In the general formulae (G1) and (G2), A is a substituted or unsubstituted fused aromatic ring having 10 to 30 carbon atoms. Ar represents a substituted or unsubstituted fused heteroaromatic ring or a substituted or unsubstituted heteroaromatic ring having 10 to 30 carbon atoms; 1 No To Ar 6 each independently represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms; And X 1 ~X 12 are each independently a branched alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, R represents one of the alkylsilyl groups; 1 ~R 10 are independently hydrogen, carbon alkyl groups having 3 to 10 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 10 carbon atoms, a trialkylsilyl group having 3 to 12 carbon atoms;

[0192] Examples of the aromatic hydrocarbon group having 6 to 13 carbon atoms include a phenyl group, a biphenyl group, and a naphthyl group. , fluorenyl group, etc. However, the aromatic hydrocarbon group is not limited to these. In addition, when the aromatic hydrocarbon group has a substituent, the substituent may be a methyl group, an ethyl group, or the like. , propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert alkyl groups having 1 to 7 carbon atoms, such as butyl, pentyl, and hexyl groups; butyl group, cyclohexyl group, cycloheptyl group, 8,9,10-trinorbornanyl group cycloalkyl groups having 5 to 7 carbon atoms such as phenyl, naphthyl, and biphenyl; Examples of suitable aryl groups include aryl groups having 6 to 12 carbon atoms, such as the group.

[0193] In the general formula (G1), a substituted or unsubstituted fused aromatic ring having 10 to 30 carbon atoms or The 10 to 30 substituted or unsubstituted fused heteroaromatic rings represent the above-mentioned luminophores, and the above-mentioned skeleton In addition, in the general formulas (G1) and (G2), X 1 ~X 12 is a protecting group Represents.

[0194] In addition, in the general formula (G2), the protecting group is connected to the luminophore quinacride via an aromatic hydrocarbon group. By using this structure, the protecting group is arranged to cover the luminophore. Therefore, energy transfer by the Dexter mechanism can be suppressed. It is also possible for the luminophore to have a protecting group that is directly bonded to the luminophore.

[0195] The energy acceptor material is preferably a compound represented by the following general formula (G3) or (G4): Organic compounds that can be used in the present invention can be suitably used.

[0196] [ka]

[0197] In the general formulae (G3) and (G4), A is a substituted or unsubstituted fused aromatic ring having 10 to 30 carbon atoms. X represents an aromatic ring or a substituted or unsubstituted fused heteroaromatic ring having 10 to 30 carbon atoms; 1 ~X 12are each independently a branched chain alkyl group having 3 to 10 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 10 carbon atoms; trialkylsilyl groups having 3 to 10 carbon atoms; R represents one of the aryl groups. 1 , R 3 , R 6 and R 8 are each independently hydrogen, 3 carbon atoms an alkyl group having from 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having from 3 to 10 carbon atoms, a trialkylsilyl group having 3 to 12 carbon atoms;

[0198] It is also preferred that the protecting group is bonded to the luminophore via a phenylene group. By doing so, the protecting group can be placed to cover the luminophore, resulting in a Dexter mechanism. In addition, the luminophore and the protecting group can suppress the energy transfer caused by the phenylene group. When two protecting groups are bonded to the phenylene group, the phenylene group is represented by the general formula (G3) and As shown in G4), the two protecting groups are preferably attached at the meta position relative to the phenylene group. This structure allows the luminophores to be covered efficiently, making it possible to The organic compound represented by general formula (G3) An example of such a product is the above-mentioned 2tBu-mmtBuDPhA2Anth. That is, in one embodiment of the present invention, general formula (G3) is a particularly preferred example.

[0199] The energy acceptor material is an organic compound represented by the following general formula (G5): The material can be suitably used.

[0200] [ka]

[0201] In general formula (G5), X 1 ~X 8 are each independently a branched chain alkyl group having 3 to 10 carbon atoms. alkyl group, substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, represents one of 10 or less trialkylsilyl groups, R 11 ~R 18 are independent hydrogen, branched alkyl groups having 3 to 10 carbon atoms, substituted or unsubstituted alkyl groups having 3 or more carbon atoms, Cycloalkyl groups having 10 or less carbon atoms, trialkylsilyl groups having 3 or more and 10 or less carbon atoms, and substituted or unsubstituted alkylsilyl groups. or an unsubstituted aryl group having 6 to 25 carbon atoms.

[0202] Examples of the aryl group having 6 to 25 carbon atoms include a phenyl group, a naphthyl group, a biphenyl group, and a phenyl group. Examples of the alkyl group include a fluorenyl group, a spirofluorenyl group, and the like. The aryl group having 5 or less carbon atoms is not limited to these. The substituents include the above-mentioned alkyl groups having 1 to 10 carbon atoms, and alkyl groups having 3 to 10 carbon atoms. a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms; Examples include trialkylsilyl groups having 3 to 10 carbon atoms.

[0203] Anthracene compounds have high luminescence quantum yields and small luminophore areas, so protecting groups can The upper and lower surfaces of the anthracene can be efficiently covered. An example of such an organic compound is the aforementioned 2tBu-mmtBuDPhA2Anth. can be.

[0204] An example of the compounds represented by the general formulas (G1) to (G5) is represented by the structural formula (102) below: The general formulas (G1) to (G5) are shown in (105) and (200) to (284). The compounds represented by the structural formulas (102) to (105) are not limited to these. The compounds shown in (200) to (284) can be used as guest materials for light-emitting elements of embodiments of the present invention. However, the guest material is not limited to these.

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[0213]

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[0227] Further, an example of a material that can be suitably used as a guest material in a light-emitting element of one embodiment of the present invention is The guest materials are shown in structural formulas (100) and (101). However, the guest materials are not limited to these.

[0228] [ka]

[0229] When compound 133 functions as an energy donor, for example, using TADF materials The energy difference between the S1 level and the T1 level of the compound 133 is preferably small. Specifically, it is greater than 0 eV and equal to or less than 0.2 eV.

[0230] When compound 133 is a TADF material, it has a structure with a hole transporting property and an electron transporting property. Alternatively, compound 133 may have a π-electron rich backbone or aromatic It is preferable that the compound has an aromatic amine skeleton and a π-electron deficient skeleton. In addition, the donor-acceptor excited state of compound 133 is easily formed within the molecule. The structure is designed to have electron-transporting and hole-transporting properties so that both donor and acceptor properties are strong within the molecule. It is preferable that the structure has a structure in which the skeleton having transport properties is directly bonded to the π electron. The structure has a structure in which an excess skeleton or an aromatic amine skeleton is directly bonded to a π-electron deficient skeleton. By strengthening both donor and acceptor properties within the molecule, the compound 133 Regions where molecular orbitals in HOMO are distributed and regions where molecular orbitals in LUMO are distributed The overlap between the singlet excited energy level and triplet excited energy level of compound 133 can be reduced. It is possible to reduce the energy difference with the excited energy level. This allows the triplet excited energy level of 3 to be kept at a high energy level.

[0231] When a TADF material is composed of one type of material, for example, the following materials can be used: can.

[0232] First, fullerene and its derivatives, acridine derivatives such as proflavine, and eosin are listed. In addition, magnesium (Mg), zinc (Zn), cadmium (Cd), tin (S n), platinum (Pt), indium (In), or palladium (Pd) Examples of the metal-containing porphyrin include protoporphyrin. Porphyrin-tin fluoride complex (SnF2(Proto IX)), mesoporphyrin-fluoride Tin complex (SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (Sn F2 (Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride Complex (SnF2(Copro III-4Me)), Octaethylporphyrin-Fluoride Tin complex (SnF2(OEP)), etioporphyrin-tin fluoride complex (SnF2(E tio I)), octaethylporphyrin-platinum chloride complex (PtCl2OEP), etc. It can be obtained.

[0233] [ka]

[0234] In addition, as a thermally activated delayed fluorescent material composed of one kind of material, a π-electron-rich framework and Heterocyclic compounds having either or both of a π-electron deficient skeleton and a π-electron deficient skeleton can also be used. 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3 -a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ) , 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazo {4,6-diphenyl-1,3,5-triazine (abbreviation: P CCzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4 ,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4-(5 -phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphen Nyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl -9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN ), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfon DMAC-DPS, 10-phenyl-10H,10'H-spiro[acrydiphenyl] 4-(9'-phen-9,9'-anthracene)-10'-one (abbreviation: ACRSA), (3,3'-bi-9H-carbazol-9-yl)benzofuro[3,2-d]pyrimidinyl 4-[4-(9'-phenyl-3,3'-bi-9H -carbazol-9-yl)phenyl]benzofuro[3,2-d]pyrimidine (abbreviation: 4 PCCzPBfpm), 9-[3-(4,6-diphenyl-1,3,5-triazine-2 -yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mP The heterocyclic compound includes a π-electron-rich heteroaromatic ring and and a π-electron-deficient heteroaromatic ring, and therefore has high electron transport properties and hole transport properties, which is preferable. Among the skeletons with π-electron-deficient heteroaromatic rings, pyridine skeletons and diazine skeletons (pyridine, diazine, pyr ... The methylimidine, pyrazine, pyridazine, and triazine skeletons are stable and reliable. In particular, benzofuropyrimidine skeleton and benzothienopyrimidine skeleton are preferred. The benzofuropyrazine and benzothienopyrazine skeletons have high acceptor properties and are reliable. Furthermore, among the skeletons having a π-electron-rich heteroaromatic ring, acrylic azine skeleton, phenoxazine skeleton, phenothiazine skeleton, furan skeleton, thiophene skeleton, and Since the pyrrole skeleton is stable and reliable, it is preferable that the compound has at least one of the skeletons. It is preferable that the furan skeleton is a dibenzofuran skeleton, and the thiophene skeleton is a dibenzofuran skeleton. The benzothiophene skeleton is preferable. The pyrrole skeleton is preferably an indole skeleton. Carbazole skeleton, bicarbazole skeleton, 3-(9-phenyl-9H-carbazole) A π-electron-rich heteroaromatic ring is particularly preferred. A substance in which a ring and a π-electron-deficient heteroaromatic ring are directly bonded is a donor for the π-electron-rich heteroaromatic ring. The acceptor property of the π-electron-deficient heteroaromatic ring is strong, and the singlet excited state level and the triplet excited state level are This is particularly preferable because the difference in the level of the first excited state is small. Instead of the aromatic ring, an electron-withdrawing group such as a cyano group may be bonded. As the molecule-excess skeleton, an aromatic amine skeleton, a phenazine skeleton, etc. can be used. π-electron deficient skeletons include xanthene skeleton, thioxanthene dioxide skeleton, oxanthene dioxide skeleton, Diazole skeleton, triazole skeleton, imidazole skeleton, anthraquinone skeleton, phenyl Boron-containing skeletons such as borane and boranthrene, nitriles such as benzonitrile and cyanobenzene, Aromatic rings or heteroaromatic rings with aryl or cyano groups, or carbonyl skeletons such as benzophenone , phosphine oxide skeleton, sulfone skeleton, etc. can be used. a π-electron deficient heteroaromatic ring in place of at least one of the π-electron deficient heteroaromatic ring and the π-electron rich heteroaromatic ring; A type backbone and a π-electron rich type backbone can be used.

[0235] [ka]

[0236] When Compound 133 does not have the function of converting triplet excitation energy into luminescence, Compound 1 The combinations of 31 and compound 133 or compound 131 and compound 134 are mutually exciplexed. A combination that forms a bond is preferred, but there is no particular limitation. It is preferable that one of the two has a function of transporting holes. It is preferred that one of the rings has a π-electron rich heteroaromatic ring and the other has a π-electron rich heteroaromatic ring.

[0237] Compound 131 includes zinc and aluminum metal complexes as well as oxadiazole derivatives. , triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoline Xaline derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, pyrimidine derivatives , triazine derivatives, pyridine derivatives, bipyridine derivatives, phenanthroline derivatives, etc. Other examples include aromatic amines and carbazole derivatives.

[0238] In addition, the following hole transporting materials and electron transporting materials can be used.

[0239] As the hole transporting material, a material having a higher hole transporting property than an electron transporting property can be used. x10 -6 cm 2 It is preferable that the material has a hole mobility of 1 / Vs or more. The compounds are prepared using aromatic amines, carbazole derivatives, aromatic hydrocarbons, stilbene derivatives, etc. The hole transporting material may be a polymer compound.

[0240] As a material having high hole transporting properties, for example, aromatic amine compounds such as N,N' -Di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDP PA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino ]biphenyl (abbreviation: DPAB), N,N'-bis{4-[bis(3-methylphenyl) amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-di Amine (abbreviation: DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl [N-phenylamino]benzene (abbreviation: DPA3B), and the like.

[0241] Specific examples of carbazole derivatives include 3-[N-(4-diphenylamino phenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA1 ), 3,6-bis[N-(4-diphenylaminophenyl)-N-phenylamino]-9 -phenylcarbazole (abbreviation: PCzDPA2), 3,6-bis[N-(4-diphenyl [N-(1-naphthyl)amino]-9-phenylcarbazole (abbreviation :PCzTPN2), 3-[N-(9-phenylcarbazol-3-yl)-N-phenyl 3,6-bis[N- (9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazol PCzPCA2, 3-[N-(1-naphthyl)-N-(9-phenylcarbazone] [carbazol-3-yl]amino]-9-phenylcarbazole (abbreviation: PCzPCN1) The following can be mentioned:

[0242] Other carbazole derivatives include 4,4'-di(N-carbazolyl)biphene. Nyl (abbreviation: CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzoyl Zene (abbreviation: TCPB), 9-[4-(10-phenyl-9-anthryl)phenyl]- 9H-Carbazole (abbreviation: CzPA), 1,4-bis[4-(N-carbazolyl)phenyl] nyl]-2,3,5,6-tetraphenylbenzene, etc. can be used.

[0243] Furthermore, examples of aromatic hydrocarbons include 2-tert-butyl-9,10-di(2- naphthyl)anthracene (abbreviation: t-BuDNA), 2-tert-butyl-9,10- Di(1-naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene thracene (abbreviation: DPPA), 2-tert-butyl-9,10-bis(4-phenylphenyl) phenyl)anthracene (abbreviation: t-BuDBA), 9,10-di(2-naphthyl)anthracene Helical anthracene (abbreviated as DNA), 9,10-diphenylanthracene (abbreviated as DPAnth), 2-tert-butylanthracene (abbreviation: t-BuAnth), 9,10-bis(4- Methyl-1-naphthyl)anthracene (abbreviation: DMNA), 2-tert-butyl-9, 10-bis[2-(1-naphthyl)phenyl]anthracene, 9,10-bis[2-(1 -naphthyl)phenyl]anthracene, 2,3,6,7-tetramethyl-9,10-di( 1-naphthyl)anthracene, 2,3,6,7-tetramethyl-9,10-di(2-naphthyl)anthracene thyl)anthracene, 9,9'-bianthryl, 10,10'-diphenyl-9,9'- Bianthryl, 10,10'-bis(2-phenylphenyl)-9,9'-bianthryl , 10,10'-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9' -Bianthryl, anthracene, tetracene, rubrene, perylene, 2,5,8,11- tetra(tert-butyl)perylene, etc. In addition, pentacene, Years etc. can also be used. In this way, 1 × 10 -6 cm 2 Hole mobility above / Vs It is more preferable to use an aromatic hydrocarbon having 14 to 42 carbon atoms.

[0244] The aromatic hydrocarbon may have a vinyl skeleton. Examples of aromatic hydrocarbons include 4,4'-bis(2,2-diphenylvinyl)biphenyl. (abbreviation: DPVBi), 9,10-bis[4-(2,2-diphenylvinyl)phenyl] anthracene (abbreviation: DPVPA), etc.

[0245] In addition, poly(N-vinylcarbazole) (abbreviation: PVK) and poly(4-vinyltriphenyl ether) Nylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenyl amino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide]( abbreviation: PTPDMA), poly[N,N'-bis(4-butylphenyl)-N,N'-bis Polymer compounds such as [(phenyl)benzidine] (abbreviation: Poly-TPD) can also be used. can.

[0246] Furthermore, examples of materials with high hole transport properties include 4,4'-bis[N-(1-naphthyl) )-N-phenylamino]biphenyl (abbreviation: NPB or α-NPD) and N,N'-biphenyl (3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4 '-diamine (abbreviation: TPD), 4,4',4''-tris(carbazol-9-yl) Triphenylamine (abbreviation: TCTA), 4,4',4''-tris[N-(1-naphthyl) 1'-TNATA, 4,4'-N-phenylamino]triphenylamine ,4''-Tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA ), 4,4',4''-tris[N-(3-methylphenyl)-N-phenylamino] Triphenylamine (abbreviation: MTDATA), 4,4'-bis[N-(spiro-9,9'- Bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), 4- Phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: B PAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenyl Aminomethyl-2-(9,9-dimethyl-9H-fluorene) yl)-N-{9,9-dimethyl-2-[N'-phenyl-N'-(9,9-dimethyl- 9H-fluoren-2-yl)amino]-9H-fluoren-7-yl}phenylamine (abbreviation: DFLADFL), N-(9,9-dimethyl-2-diphenylamino-9H-fluoren-2-yl) Fluoren-7-yl)diphenylamine (abbreviation: DPNF), 2-[N-(4-diphenyl) N-phenylaminophenyl)spiro-9,9'-bifluorene (abbreviation: D PASF), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl) PCBA1BP, 4,4'-diphenyl-4''-(9-phenyl- (phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP) ), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl) Triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-( 9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNB) B) 4-phenyldiphenyl-(9-phenyl-9H-carbazol-3-yl)amine N,N'-bis(9-phenylcarbazol-3-yl)- N,N'-diphenylbenzene-1,3-diamine (abbreviation: PCA2B), N,N',N ''-Triphenyl-N,N',N''-tris(9-phenylcarbazol-3-yl) ) Benzene-1,3,5-triamine (abbreviation: PCA3B), N-(4-biphenyl)- N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carba azole-3-amine (abbreviation: PCBiF), N-(1,1'-biphenyl-4-yl)- N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl 9,9-dimethyl-N- Phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]- Fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl -9H-carbazol-3-yl)phenyl]-spiro-9,9'-bifluorene-2- Amine (abbreviation: PCBASF), 2-[N-(9-phenylcarbazol-3-yl)- N-phenylamino]spiro-9,9'-bifluorene (abbreviation: PCASF), 2,7- Bis[N-(4-diphenylaminophenyl)-N-phenylamino]-spiro-9,9 '-bifluorene (abbreviation: DPA2SF), N-[4-(9H-carbazol-9-yl )phenyl]-N-(4-phenyl)phenylaniline (abbreviation: YGA1BP), N,N '-Bis[4-(carbazol-9-yl)phenyl]-N,N'-diphenyl-9,9 -Dimethylfluorene-2,7-diamine (abbreviation: YGA2F) and other aromatic amine compounds Also, 3-[4-(1-naphthyl)-phenyl]-9-phenyl can be used. 9H-carbazole (abbreviation: PCPN), 3-[4-(9-phenanthryl)- phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPPn), 3,3'-bis( 9-phenyl-9H-carbazole) (abbreviation: PCCP), 1,3-bis(N-carbazole) mCP, 3,6-bis(3,5-diphenylphenyl)-9- Phenylcarbazole (abbreviation: CzTP), 4-{3-[3-(9-phenyl-9H-phenyl) (mmDBFFLBi -II), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) DBF3P-II), 1,3,5-tri(dibenzothiophen-4-yl) -benzene (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl [(9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP) -III), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6 -phenyldibenzothiophene (abbreviation: DBTFLP-IV), 4-[3-(triphenyl (2-phenyl)dibenzothiophene (abbreviation: mDBTPTp-II) Mine compounds, carbazole compounds, thiophene compounds, furan compounds, fluorene compounds , triphenylene compounds, phenanthrene compounds, etc. can be used. The substance is mainly 1×10 -6 cm 2 A material with a hole mobility of 1 / Vs or more. Any other substance may be used as long as it has a higher hole transporting property than electron transporting property.

[0247] As the electron transporting material, a material having a higher electron transporting property than a hole transporting property can be used. x10 -6 cm 2 It is preferable that the material has an electron mobility of 1 / Vs or more. Nitrogen-containing heteroaromatic compounds are examples of materials that are easily absorbed (materials with electron transport properties). π-electron deficient heteroaromatic compounds and metal complexes can be used. Quinoline, benzoquinoline, oxazole, or thiazole ligands metal complexes having the same, oxadiazole derivatives, triazole derivatives, phenanthroline derivatives conductors, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and the like.

[0248] For example, tris(8-quinolinolato)aluminum(III) (abbreviation: Alq), tri Bis(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), Bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2 ), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum ( III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq) and metal complexes having a quinoline skeleton or a benzoquinoline skeleton, such as: In addition, bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnP BO), bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnB Metal complexes with oxazole or thiazole ligands such as TZ can also be used. In addition to metal complexes, 2-(4-biphenylyl)-5-(4-tert- butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD) and 1,3-bis[ 5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzyl Benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazo 3-(4-biphenyl-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), (4-tert-butylphenyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-thiazolinone TAZ (abbreviation: TAZ), 2,2',2''-(1,3,5-benzenetriyl)tris(triazol) (1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzo [4-( ... : mDBTBIm-II), bathophenanthroline (abbreviation: BPhen), 2,9-bis (Naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: Heterocyclic compounds such as NBPhen and bathocuproine (abbreviated as BCP), and 2-[3- (Dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl [2m-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II) , 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f ,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4-(3,6-diphenyl- 9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2 CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzyl benzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II) and 6-[3-( Dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6 mDBTPDBq-II), 4,6-bis[3-(phenanthrene-9-yl)phenyl ]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothiene 4,6-bis[(phenyl)pyrimidine (abbreviation: 4,6mDBTP2Pm-II) 3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2 Heterocyclic compounds with diazine skeletons such as 2-{4-[3-(N-phenyl- 9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6 -diphenyl-1,3,5-triazine (abbreviated as PCCzPTzn) and other triazine skeletons Heterocyclic compounds with hexagonal rings and 3,5-bis[3-(9H-carbazol-9-yl)phenyl] 1,3,5-tri[3-(3-pyridyl) heterocyclic compounds having a pyridine skeleton, such as phenyl]benzene (abbreviation: TmPyPB), 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzO Heteroaromatic compounds such as poly(2,5-pyridinedione) can also be used. Poly[(9,9-dihexylfluorene-2,7-diyl)-c o-(pyridine-3,5-diyl)] (abbreviation: PF-Py), poly[(9,9-dioctyl (2,2'-bipyridine-6,6'-diyl)-co-(2,2'-bipyridine-2,7-diyl) ] (abbreviation: PF-BPy) can also be used. The quality is mainly 1x10 -6 cm 2 It is a substance with an electron mobility of 1 / Vs or more. Substances other than those mentioned above may be used as long as they have a higher electron transporting property than the above-mentioned substances.

[0249] Compound 133 or Compound 134 is a material capable of forming an exciplex with Compound 131. Specifically, it is preferable to use the hole transporting material and the electron transporting material shown above. In this case, Compound 131 and Compound 133 or Compound 131 and Compound 134 The emission peak of the exciplex formed by Compound 131 and Compound 133 or Compound 13 It is preferable to select Compound 1, Compound 134, and Compound 132 (fluorescent material). This makes it possible to provide a light-emitting element with dramatically improved luminous efficiency.

[0250] Furthermore, a phosphorescent material can be used as the compound 133. , iridium, rhodium, or platinum-based organometallic complexes or metal complexes. Other examples include platinum complexes and organic iridium complexes with porphyrin ligands, among which For example, organic iridium complexes such as iridium orthometal complexes are preferred. The ligands that can be bonded include 4H-triazole ligands, 1H-triazole ligands, imidazole ligands, and the like. Zole ligand, pyridine ligand, pyrimidine ligand, pyrazine ligand, or isoquino ligand In this case, compound 133 (phosphorescent material) is a triplet MLCT (Metal to Ligand Charge Transfer) transition absorption band The emission peak of Compound 133 is on the longest wavelength side of Compound 132 (fluorescent material). Compound 133 and Compound 132 (fluorescent material) were added so that they overlapped with the absorption bands of the fluorescein-like compound (low energy side). This makes it possible to obtain a light-emitting element with dramatically improved luminous efficiency. In addition, even if Compound 133 is a phosphorescent material, it can be excited with Compound 131. When forming an exciplex, the phosphorescent material must emit light at room temperature. It is not necessary to have a specific structure, but rather it is necessary to have the exciplex emit light at room temperature when it is formed. pz)3 can be used as the phosphorescent material.

[0251] Examples of substances having a blue or green emission peak include tris{2-[5-(2 -methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazo 3-yl-κN 2 ]phenyl-κC}iridium(III) (abbreviation: Ir(mpp tz-dmp)3), tris(5-methyl-3,4-diphenyl-4H-1,2,4-trimethyl- Triazolato)iridium(III) (abbreviation: Ir(Mptz)3), tris[4-(3- Biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato]i Iridium(III) (abbreviation: Ir(iPrptz-3b)3), tris[3-(5-biphenyl] (phenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazolato]irid Ir(III) (abbreviated as Ir(iPr5btz)3), a 4H-triazole skeleton and organometallic iridium complexes with tris[3-methyl-1-(2-methylphenyl) -5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: Ir (Mptz1-mp)3), tris(1-methyl-5-phenyl-3-propyl-1H- 1,2,4-Triazolate)iridium(III) (abbreviation: Ir(Prtz1-Me) 3) and fac-triazole-based organometallic iridium complexes. S[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]isopropyl Iridium(III) (abbreviation: Ir(iPrpmi)3), tris[3-(2,6-dimethyl phenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(I II) Imidazole skeleton-containing compounds such as Ir(dmpimpt-Me) Organic metal iridium complexes and bis[2-(4',6'-difluorophenyl)pyridinato- N,C 2’]iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FI r6), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ ]Ili Dium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis (Trifluoromethyl)phenyl]pyridinato-N,C 2’}Iridium(III) pico Ir(CF3ppy)2(pic) (fluorophenyl)pyridinato-N,C 2’ ]Iridium(III) acetylacetonate (abbreviation: FIr(acac)) Among the above, 4H-triazole is an organometallic iridium complex. a nitrogen-containing five-membered heterocyclic skeleton such as a 1H-triazole skeleton and an imidazole skeleton; The organometallic iridium complexes have high triplet excitation energy and are highly reliable and highly efficient. It is particularly preferred because it is also excellent in

[0252] Furthermore, examples of substances having a green or yellow emission peak include tris(4-methylphenyl) Ir(mppm)3, Tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: I r(tBuppm)3), (acetylacetonato)bis(6-methyl-4-phenylpyridine) Iridium(III) (abbreviation: Ir(mppm)2(acac)), (acetylacetonate ruacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium( III) (Abbreviation: Ir(tBuppm)2(acac)), (acetylacetonato)bis [4-(2-norbornyl)-6-phenylpyrimidinato]iridium(III) (abbreviation : Ir(nbppm)2(acac)), (acetylacetonato)bis[5-methyl-6 -(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: Ir(mpmppm)2(acac)), (acetylacetonato)bis{4,6-dimethyl 2-[6-(2,6-dimethylphenyl)-4-pyrimidinyl-κN 3 ]phenyl- κC}iridium(III) (abbreviation: Ir(dmppm-dmp)2(acac)), ( acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III)( Organometallic iridium compounds with pyrimidine skeletons, such as Ir(dppm)2(acac) complexes and (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazine Iridium(III) (abbreviation: Ir(mppr-Me)2(acac)), (acetyl arylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinato)iridide Pyrazine skeletons such as Ir(III) (abbreviation: Ir(mppr-iPr)2(acac)) Organometallic iridium complexes and tris(2-phenylpyridinato-N,C 2’ ) Iridium(III) (abbreviation: Ir(ppy)3), bis(2-phenylpyridinato-N ,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(ppy)2(ac ac)), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: Ir(bzq)2(acac)), tris(benzo[h]quinolinato)iridium Ir(III) (abbreviation: Ir(bzq)3), tris(2-phenylquinolinato-N,C 2 ’ ) Iridium(III) (abbreviation: Ir(pq)3), bis(2-phenylquinolinato- N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(pq)2(ac Organometallic iridium complexes with pyridine skeletons such as bis(2,4-difluoromethyl) Phenyl-1,3-oxazolato-N,C 2’ ) Iridium(III) acetylacetoner Ir(dpo)2(acac)), bis{2-[4'-(perfluorophenyl) (phenyl)pyridinato-N,C 2’}Iridium(III) acetylacetonate( Abbreviation: Ir(p-PF-ph)2(acac)), bis(2-phenylbenzothiazol- -N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(bt)2(a In addition to organometallic iridium complexes such as tris(acetylacetonato)(monophenyl) Anthroline) terbium(III) (abbreviation: Tb(acac)3(Phen)) Among the above, organometallic iridium complexes having a pyrimidine skeleton are Dium complexes are particularly preferred because they are remarkably excellent in reliability and luminous efficiency.

[0253] Furthermore, examples of substances having a yellow or red emission peak include (diisobutyryl) Methanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(II I) (abbreviation: Ir(5mdppm)2(dibm)), bis[4,6-bis(3-methyl [phenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: Ir (5mdppm)2(dpm)), bis[4,6-di(naphthalen-1-yl)pyrimidinyl] Nato](dipivaloylmethanato)iridium(III) (abbreviation: Ir(d1npm)2( Organometallic iridium complexes with pyrimidine skeletons, such as (acetylacetonyl acetone) Iridium(III) (abbreviation: I r(tppr)2(acac)), bis(2,3,5-triphenylpyrazinate)(dipyr Valoylmethanato)iridium(III) (abbreviation: Ir(tppr)2(dpm)), ( Acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]i Ir(Fdpq)2(acac) and other pyrazine-based compounds Organometallic iridium complexes and tris(1-phenylisoquinolinato-N,C 2’ ) Iridium(III) (abbreviation: Ir(piq)3), bis(1-phenylisoquinolinato) -N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(piq)2( In addition to organometallic iridium complexes with pyridine skeletons such as acac), 2,3,7, 8,12,13,17,18-Octaethyl-21H,23H-porphyrin platinum(II) ) (abbreviation: PtOEP) and tris(1,3-diphenyl-1,3-propanediol). Eu(DB)(propanedionato)(monophenanthroline)europium(III) M)3(Phen)), tris[1-(2-thenoyl)-3,3,3-trifluoroacetate [Tonato](monophenanthroline)europium(III) (abbreviation: Eu(TTA)3( Among the above, rare earth metal complexes such as pyrimidine skeletons are Organometallic iridium complexes having the above structure are particularly preferred because they are remarkably excellent in reliability and luminous efficiency. In addition, organometallic iridium complexes with a pyrazine skeleton can emit red light with good chromaticity. can be done.

[0254] Furthermore, materials that can be used as the above-mentioned energy donor include metal halides. The metal halide perovskites include the following: It can be represented by any of the general formulae (g1) to (g3).

[0255] (SA)MX3:(g1) (LA)2(SA) n-1 M n X 3n+1 :(g2) (PA)(SA) n-1 M n X3 n+1 :(g3)

[0256] In the above general formula, M represents a divalent metal ion, and X represents a halogen ion.

[0257] Specifically, divalent cations such as lead and tin are used as divalent metal ions. .

[0258] Specifically, anions of chlorine, bromine, iodine, fluorine, etc. are used as halogen ions. I can.

[0259] Furthermore, n represents an integer of 1 to 10, but in general formula (g2) or general formula (g3), When n is greater than 10, the properties are similar to those of the metal halide represented by the general formula (g1): It is close to perovskites.

[0260] Also, LA is R 30 -NH3 + represents an ammonium ion represented by the formula:

[0261] General formula R 30 -NH3+ In the ammonium ion represented by R 30 has 2 to 10 carbon atoms any one of 20 alkyl groups, aryl groups, and heteroaryl groups, or a group having 2 to 20 carbon atoms an alkyl group, an aryl group, or a heteroaryl group, and an alkylene group having 1 to 12 carbon atoms a combination of a vinylene group, an arylene group having 6 to 13 carbon atoms, and a heteroarylene group; In the latter case, the alkylene group, the arylene group, and the heteroarylene group are each a group consisting of a plurality of groups. The alkylene may be a group of several groups, and a plurality of groups of the same type may be used. When a plurality of alkyl groups, vinylene groups, arylene groups, and heteroarylene groups are connected, The total number of arylene, vinylene, arylene, and heteroarylene groups is 35 or less. is preferred.

[0262] SA is a monovalent metal ion or R 31 -NH3 + and R 31 carbon number 1 to 6 alkyl group represents an ammonium ion.

[0263] In addition, PA is NH3 + -R 32 -NH3 + or NH3 + -R 33 -R 34 -R 35 -NH3 + or a portion of a branched polyethyleneimine having an ammonium cation, or The valence of the part is +2. The charges in the general formula are almost balanced. .

[0264] Here, the charge of metal halide perovskites is calculated by the above formula: It is not necessary to strictly balance the temperature, but it is sufficient if the neutrality of the entire material is maintained. There are free ammonium ions, free halogen ions, and impurity ions locally in the material. Other ions such as ions may be present, which may neutralize the charge. In addition, when neutrality is not maintained locally on the surface of particles or films, or on the grain boundaries of crystals, Neutrality does not necessarily have to be maintained in all locations.

[0265] In addition, (LA) in the above formula (g2) may be, for example, any of the following general formulae (a-1) to (a-1 1), substances represented by general formulas (b-1) to (b-6), etc. can be used.

[0266] [ka]

[0267] [ka]

[0268] In addition, (PA) in the above general formula (g3) is typically represented by the following general formula (c-1), (c -2) and (d) and a branched polymer having an ammonium cation It represents part or all of a compound such as triethyleneimine, and has a +2 charge. These polymers may have charge neutralization across multiple unit cells and may have different The charge of one unit cell is neutralized by one charge of each of the two polymer molecules. In some cases, this may be the case.

[0269] [ka]

[0270] [ka]

[0271] However, in the above general formula, R 20 represents an alkyl group having 2 to 18 carbon atoms, and R 21 , R 2 2 and R 23 represents hydrogen or an alkyl group having 1 to 18 carbon atoms; R 24 is the following structural formula and the general formula (R 24 -1)~(R 24 -14). Also, R 25 and R 26 teeth Each X independently represents hydrogen or an alkyl group having 1 to 6 carbon atoms. A combination of monomer units A and B represented by any of the combinations of (d-1) to (d-6) It represents a structure containing u A's and v B's. The order of A and B is Furthermore, m and l are each independently an integer of 0 to 12, and t is an integer of 1 to 12. 18. Furthermore, u is an integer between 0 and 17, v is an integer between 1 and 18, and u+v is an integer from 1 to 18.

[0272] [ka]

[0273] These are just examples, and the substances that can be used as (LA) and (PA) are not listed here. It is not limited to.

[0274] A three-dimensional metal halide having the composition (SA)MX3 represented by the general formula (g1) Perovskites have a metal atom M at the center and halogen atoms at the six vertices. The octahedral structure forms a skeleton by arranging itself three-dimensionally, sharing the halogen atoms at each vertex. The structural unit of this regular octahedron with a halogen atom at each vertex is called a perovskite unit. This perovskite unit exists in isolation, forming a zero-dimensional structure. Linear structures connected one-dimensionally via halogen atoms at the vertices, and sheets connected two-dimensionally There are structures with perovskite units connected in two dimensions, and structures with perovskite units connected in three dimensions. Complex two-dimensional structures can also be formed by stacking multiple layers of interlocking sheet-like structures. There are also more complex structures. The general term for all structures that contain these perovskite units is As such, we define them as metal halide perovskites.

[0275] The light-emitting layer 130 may be composed of two or more layers. When the light-emitting layer 130 is formed by laminating the first light-emitting layer and the second light-emitting layer in this order from the hole transport layer side, a substance having hole transport properties is used as a host material for the first light-emitting layer, and a substance having hole transport properties is used as a host material for the second light-emitting layer For example, a substance having an electron transport property is used as the light emitting element.

[0276] In the light-emitting layer 130, the compounds 131, 132, 133 and 134 are In this case, the compound 131 and the compound 134 may contain a material other than the compound 135. In order for compound 133 (or compound 134) to efficiently form an exciplex, compound 13 The HOMO level of either compound 1 or compound 133 (or compound 134) is the other LUMO level is the material in the light-emitting layer 130. It is preferable that the LUMO level of the compound is the lowest among the above. By doing so, it is possible to suppress the reaction of compound 131 and compound 135 to form an exciplex. Cut.

[0277] For example, Compound 131 has hole transporting properties, and Compound 133 (or Compound 134) has electron transporting properties. When compound 131 has electron transport properties, the HOMO level of compound 131 is higher than that of compound 133. The HOMO level of the compound 133 is preferably higher than the HOMO level of the compound 135. It is preferable that the LUMO level is lower than that of Compound 131 and that of Compound 135. In this case, the LUMO level of compound 135 is higher than that of compound 131. The HOMO level of compound 135 may be lower than the HOMO level of compound 133. It can be high or low.

[0278] The material (compound 135) that can be used for the light-emitting layer 130 is not particularly limited, but For example, tris(8-quinolinolato)aluminum(III) (abbreviation: Alq), tris(8-quinolinolato)aluminum(III) Bis(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), Bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2 ), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum ( III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq) , bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO ), bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ ), metal complexes such as 2-(4-biphenylyl)-5-(4-tert-butylphenyl) -1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(p-tert -butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OX D-7), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl) 2,2',2''-(1,3,5-triazole) -benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TP BI), bathophenanthroline (abbreviated as BPhen), bathocuproine (abbreviated as BCP) ), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl] Heterocyclic compounds such as -9H-carbazole (abbreviation: CO11), 4,4'-bis[N-( 1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB or α-NPD), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl 4,4'-bis[N-(spiro-9,9' -bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), etc. In addition, aromatic amine compounds such as anthracene derivatives and phenanthrene derivatives can be used. , pyrene derivatives, chrysene derivatives, dibenzo[g,p]chrysene derivatives, and other condensed polycyclic aromatic compounds Specific examples include 9,10-diphenylanthracene (abbreviation: DPAn th), N,N-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl ]-9H-carbazol-3-amine (abbreviation: CzA1PA), 4-(10-phenyl- 9-Anthryl)triphenylamine (abbreviation: DPhPA), 4-(9H-carbazole -9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl] Phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), N,9-diphenyl -N-{4-[4-(10-phenyl-9-anthryl)phenyl]phenyl}-9H- Carbazol-3-amine (abbreviation: PCAPBA), N,9-diphenyl-N-(9,1 0-Diphenyl-2-anthryl)-9H-carbazol-3-amine (abbreviation: 2PCA) PA), 6,12-dimethoxy-5,11-diphenylchrysene, N,N,N',N', N'',N'',N''',N'''-Octaphenyldibenzo[g,p]chrysene-2 ,7,10,15-tetraamine (abbreviation: DBC1), 9-[4-(10-phenyl-9 -anthryl)phenyl]-9H-carbazole (abbreviation: CzPA), 3,6-diphenyl 9H-carbazole (4-(10-phenyl-9-anthryl)phenyl) Abbreviation: DPCzPA), 9,10-bis(3,5-diphenylphenyl)anthracene ( DPPA), 9,10-di(2-naphthyl)anthracene (DNA), 2- tert-Butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA ), 9,9'-bianthryl (abbreviation: BANT), 9,9'-(stilbene-3,3'- Diyl)diphenanthrene (abbreviation: DPNS), 9,9'-(stilbene-4,4'-di 1,3,5-tri(1-pyrenyl)benzoate (abbreviation: DPNS2), Among these and other known substances, Therefore, the energy gap is larger than that of Compound 131 and Compound 132. One or more substances having a cross-linking group may be selected and used.

[0279] <Pair of electrodes> The electrode 101 and the electrode 102 have the function of injecting holes and electrons into the light-emitting layer 130. The electrodes 101 and 102 are made of metals, alloys, conductive compounds, and mixtures or laminates thereof. It can be formed using aluminum (Al) as a typical example of a metal. , and other transition metals such as silver (Ag), tungsten, chromium, molybdenum, copper, and titanium. , alkali metals such as lithium (Li) and cesium, calcium, magnesium (Mg) Group 2 metals such as ytterbium (Yb) can be used as transition metals. A rare earth metal may be used. As the alloy, an alloy containing the above metals may be used. Examples of the conductive compound include MgAg and AlLi. Indium tin oxide (ITO), silicon or silicon oxide Including indium tin oxide (ITSO), indium zinc oxide (Indium Zinc Oxide) inc Oxide), tungsten and zinc-containing indium oxide, etc. As the conductive compound, an inorganic carbon material such as graphene may be used. As described above, electrodes 101 and 102 are formed by stacking multiple layers of these materials. 2 or both may be formed.

[0280] The light emitted from the light-emitting layer 130 is emitted from one or both of the electrodes 101 and 102. Therefore, at least one of the electrodes 101 and 102 is visible. Conductive materials that have the function of transmitting light include those that transmit visible light. The transmittance is 40% or more and 100% or less, preferably 60% or more and 100% or less, and the resistance Resistivity is 1×10 -2Electrically conductive materials with a conductivity of Ω·cm or less are also used. The electrode is made of a conductive material that has the function of transmitting and reflecting light. The conductive material has a visible light reflectance of 20% or more and 80% or less, preferably 4 0% or more and 70% or less, and the resistivity is 1×10 -2 Conductive materials with a resistance of Ω·cm or less When a material with low optical transparency, such as a metal or alloy, is used for the electrode that extracts light, The electrode 10 is formed with a thickness (for example, 1 nm to 10 nm) that allows visible light to pass through. Either or both of the electrode 101 and the electrode 102 may be formed.

[0281] In this specification and the like, the electrode having the function of transmitting light includes an electrode having the function of transmitting visible light. It is sufficient to use a material that has both functionality and conductivity, such as the above-mentioned ITO. In addition to the oxide conductor layer, an oxide semiconductor layer or an organic conductor layer containing an organic material is included. The organic conductive layer containing an organic substance may be, for example, a layer containing an organic compound and an electron donor. A layer containing a composite material obtained by mixing an organic compound and an electron acceptor. The resistivity of the transparent conductive layer is preferably 1×10 5 Ω·cm or less, more preferably 1×10 4 Ω·cm or less.

[0282] The electrode 101 and the electrode 102 may be formed by a sputtering method, a vapor deposition method, a printing method, or the like. Coating method, MBE (Molecular Beam Epitaxy) method, CVD method, Pulse Laser deposition method, ALD (Atomic Layer Deposition) method, etc. It can be used as appropriate.

[0283] <Hole injection layer> The hole injection layer 111 is formed by injecting holes from one of the pair of electrodes (electrode 101 or electrode 102). It has the function of promoting hole injection by reducing the injection barrier, and is used in materials such as transition metal oxides and fluorine. It is formed by phthalocyanine derivatives or aromatic amines. Examples include molybdenum oxide, vanadium oxide, ruthenium oxide, and tungsten oxide. , manganese oxide, etc. Phthalocyanine derivatives include phthalocyanine, Examples of aromatic amines include benzidine derivatives and phenyl Diamine derivatives, etc. Polymer compounds such as polythiophene and polyaniline Materials such as self-doped polythiophenes, poly(ethylenediamines), can also be used. Typical examples include poly(oxythiophene) / poly(styrenesulfonic acid).

[0284] The hole injection layer 111 is made of a compound material including a hole transporting material and a material that exhibits electron accepting properties. Alternatively, a layer containing a material exhibiting electron accepting properties and a layer containing a material exhibiting electron accepting properties may be used. A stack of layers containing hole transport materials may also be used. It is possible to exchange charges in the presence of a magnetic field. Materials that exhibit electron-accepting properties include quinodimethane. Organic acceptors such as benzophenone derivatives, chloranil derivatives, and hexaazatriphenylene derivatives Specifically, 7,7,8,8-tetracyano-2,3,5,6- Tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloranil, 2,3,6,7, 10,11-Hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation Name: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinone Electron-withdrawing groups (especially halogens such as fluoro groups) such as benzodimethanone (abbreviated as F6-TCNNQ) In particular, compounds with multiple groups such as HAT-CN can be mentioned. Compounds in which electron-withdrawing groups are bonded to condensed aromatic rings with multiple carbon atoms are thermally stable. It is also preferable that the compound has an electron-withdrawing group (particularly a halogen group such as a fluoro group or a cyano group). [3] Radialene derivatives are preferred because they have very high electron-accepting properties. Specifically, α,α' ,α''-1,2,3-cyclopropanetriylidenetris[4-cyano-2,3,5, 6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclo Propanetriylidene tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)propane] (Omethyl)benzeneacetonitrile], α,α',α''-1,2,3-cyclopropane Entriylidene tris[2,3,4,5,6-pentafluorobenzeneacetonitrile] In addition, oxides of transition metals, for example, oxides of metals from Groups 4 to 8, are used. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, , molybdenum oxide, tungsten oxide, manganese oxide, rhenium oxide, etc. Molybdenum oxide is preferred because it is stable in the air, has low hygroscopicity, and is easy to handle.

[0285] As the hole transporting material, a material having a higher hole transporting property than an electron transporting property can be used. x10 -6 cm 2 It is preferable that the material has a hole mobility of 1 / Vs or more. The aromatic amines and amines listed as hole transporting materials that can be used in the light-emitting layer 130 are Carbazole derivatives can be used. Aromatic hydrocarbons and stilbene derivatives can also be used. The hole transporting material may be a polymer compound.

[0286] Examples of aromatic hydrocarbons include 2-tert-butyl-9,10-di(2-naphthyl) 2-tert-butyl-9,10-di(1-methyl-2-methyl-1,3-diphenyl ... -naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene DPPA, 2-tert-butyl-9,10-bis(4-phenylphenyl) ) anthracene (abbreviation: t-BuDBA), 9,10-di(2-naphthyl)anthracene (Abbreviation: DNA), 9,10-diphenylanthracene (Abbreviation: DPAnth), 2-t ert-butylanthracene (abbreviation: t-BuAnth), 9,10-bis(4-methyl -1-naphthyl)anthracene (abbreviation: DMNA), 2-tert-butyl-9,10- Bis[2-(1-naphthyl)phenyl]anthracene, 9,10-bis[2-(1-naphthyl)phenyl]anthracene 2,3,6,7-tetramethyl-9,10-di(1-nathyl)phenyl]anthracene anthracene, 2,3,6,7-tetramethyl-9,10-di(2-naphthyl) Anthracene, 9,9'-bianthryl, 10,10'-diphenyl-9,9'-bianthryl tolyl, 10,10'-bis(2-phenylphenyl)-9,9'-bianthryl, 10 ,10'-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9'-bis Anthracene, Anthracene, Tetracene, Rubrene, Perylene, 2,5,8,11-Tetracene (tert-butyl)perylene, etc. In addition, pentacene, coronene, etc. can also be used. In this way, 1×10 -6 cm 2 / Vs or more It is more preferable to use an aromatic hydrocarbon having 14 to 42 carbon atoms.

[0287] The aromatic hydrocarbon may have a vinyl skeleton. Examples of aromatic hydrocarbons include 4,4'-bis(2,2-diphenylvinyl)biphenyl. (abbreviation: DPVBi), 9,10-bis[4-(2,2-diphenylvinyl)phenyl] anthracene (abbreviation: DPVPA), etc.

[0288] In addition, poly(N-vinylcarbazole) (abbreviation: PVK) and poly(4-vinyltriphenyl ether) Nylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenyl amino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide]( abbreviation: PTPDMA), poly[N,N'-bis(4-butylphenyl)-N,N'-bis Polymer compounds such as [(phenyl)benzidine] (abbreviation: Poly-TPD) can also be used. can.

[0289] <Hole transport layer> The hole transport layer 112 is a layer containing a hole transport material. The hole transport layer 112 is formed by injecting the hole into the hole injection layer 111. Since it has a function of transporting holes to the light-emitting layer 130, it has the same HOMO level as the hole injection layer 111. It is preferable that the HOMO level is the same as or close to the HOMO level.

[0290] The hole transport material may be any of the materials exemplified as the material for the hole injection layer 111. Also, 1×10 -6 cm 2 / Vs or more. However, other materials may be used as long as they have a higher hole transporting property than an electron transporting property. The layer containing a substance with a high hole transporting property may be not only a single layer but also a layer containing the above-mentioned substance. Two or more layers may be laminated.

[0291] ≪Electron transport layer≫ The electron transport layer 118 is connected to the other of the pair of electrodes (electrode 101 or electrode 102) via the electron injection layer 119. The electron transport material has the function of transporting electrons injected from the electrode 102 to the light-emitting layer 130. As the material, a material with higher electron transportability than holes can be used, and the -6 cm 2 It is preferable that the material has an electron mobility of 1 / Vs or more. As materials (materials with electron transport properties), π-electron deficient materials such as nitrogen-containing heteroaromatic compounds are Heteroaromatics and metal complexes can be used. The quinoline ligand, benzoquinoline ligand, and oxalate ligand mentioned above as electron transport materials that can Metal complexes having oxazole or thiazole ligands are also suitable. Diazole derivatives, triazole derivatives, phenanthroline derivatives, pyridine derivatives, biphenyl derivatives Pyridine derivatives, pyrimidine derivatives, etc. -6 cm 2 / Vs It is preferable that the material has an electron mobility of at least 1000 MPa. Other materials than those mentioned above may be used for the electron transport layer as long as they have high conductivity. The transport layer 118 may be a single layer or may be a laminate of two or more layers made of the above materials.

[0292] In addition, a layer for controlling the movement of electron carriers is provided between the electron transport layer 118 and the light emitting layer 130. The layer for controlling the movement of electron carriers may be made of a material having high electron transport properties as described above. A small amount of material with high electron trapping properties is added to the layer, which suppresses the movement of electron carriers. This makes it possible to adjust the carrier balance. To prevent problems caused by electrons penetrating through the layer (such as a reduction in device lifespan) It has a great effect.

[0293] ≪Electron injection layer≫ The electron injection layer 119 promotes electron injection by reducing the electron injection barrier from the electrode 102. For example, Group 1 metals, Group 2 metals, or their oxides and halides In addition, the electron transport material and the corresponding electron A composite material of a material exhibiting electron donating properties can also be used. Examples include Group 1 metals, Group 2 metals, and oxides thereof. are lithium fluoride (LiF), sodium fluoride (NaF), and cesium fluoride (CsF ), calcium fluoride (CaF2), lithium oxide (LiO x ) and other alkaline gold Metals, alkaline earth metals, or compounds thereof can be used. A rare earth metal compound such as erbium (ErF3) can be used. An electride may be used for 119. The electride may be, for example, calcium. Examples include a material in which electrons are highly concentrated in a mixed oxide of aluminum and silicon. The injection layer 119 may be made of a material that can be used in the electron transport layer 118 .

[0294] The electron injection layer 119 may contain a composite material formed by mixing an organic compound and an electron donor. Such composite materials may be formed by electron donors giving electrons to organic compounds. In this case, the organic compound is It is preferable that the material is excellent in transporting the generated electrons. Specifically, for example, the above-mentioned The material constituting the electron transport layer 118 (metal complex, heteroaromatic compound, etc.) can be used. The electron donor may be any substance that exhibits electron donating properties to organic compounds. For the metal, alkali metals, alkaline earth metals and rare earth metals are preferred, and lithium, cesium, Examples include magnesium, calcium, erbium, and ytterbium. Preferred are lithium metal oxides and alkaline earth metal oxides, and lithium oxide and calcium oxide are preferred. , barium oxide, etc. Also, Lewis bases such as magnesium oxide are used. It is also possible to use organic compounds such as tetrathiafulvalene (abbreviation: TTF). It can also be done as follows.

[0295] The above-mentioned light-emitting layer, hole-injection layer, hole-transport layer, electron-transport layer, and electron-injection layer are These are deposition method (including vacuum deposition method), inkjet method, coating method, and nozzle printing method, respectively. The light-emitting layer and the hole-injection layer can be formed by a method such as gravure printing. In addition to the above-mentioned materials, the hole transport layer, the electron transport layer, and the electron injection layer may contain other materials such as quantum dots. Inorganic compounds or polymeric compounds (oligomers, dendrimers, polymers, etc.) may be used. stomach.

[0296] Quantum dots include colloidal quantum dots, alloy quantum dots, and core-shell quantum dots. It is also possible to use quantum dots of the 2nd group and the 16th group, quantum dots of the 13th group, and the like. Contains element groups from group 15, 13 and 17, 11 and 17, or 14 and 15 Quantum dots may also be used. Alternatively, cadmium (Cd), selenium (Se), zinc (Zn ), sulfur (S), phosphorus (P), indium (In), tellurium (Te), lead (Pb), gallium Quantum dots containing elements such as Ga, As, and Al are used. It's fine.

[0297] Examples of liquid media used in wet processes include methyl ethyl ketone, cyclohexane, and the like. Ketones such as xanone, fatty acid esters such as ethyl acetate, halogens such as dichlorobenzene aromatic hydrocarbons, toluene, xylene, mesitylene, cyclohexylbenzene, etc. Hydrocarbons, aliphatic hydrocarbons such as cyclohexane, decalin, and dodecane, dimethylformamide Organic solvents such as dimethyl amide (DMF) and dimethyl sulfoxide (DMSO) can be used. Cut.

[0298] Furthermore, examples of polymer compounds that can be used in the light-emitting layer include poly[2-methoxamer] 5-(2-ethylhexyloxy)-1,4-phenylene vinylene] (abbreviation: MEH -PPV), polyphenylene such as poly(2,5-dioctyl-1,4-phenylene vinylene) Poly(9,9-di-n-octylfluorenyl-2,7-diol) -diyl) (abbreviation: PF8), poly[(9,9-di-n-octylfluorenyl-2,7 -diyl)-alt-(benzo[2,1,3]thiadiazole-4,8-diyl)](abbreviation Name: F8BT), poly[(9,9-di-n-octylfluorenyl-2,7-diyl)- alt-(2,2'-bithiophene-5,5'-diyl)] (abbreviated as F8T2), poly[( 9,9-Dioctyl-2,7-divinylenefluorenylene)-alt-(9,10-an thracene)], poly[(9,9-dihexylfluorene-2,7-diyl)-alt-( polyfluorene derivatives such as poly(3-hexyl) Polyalkylthiophenes (P) such as silthiophene-2,5-diyl (abbreviation: P3HT) AT) derivatives, polyphenylene derivatives, etc. Furthermore, these polymer compounds, PVK, poly(2-vinylnaphthalene), poly[bis(4-phenyl)(2,4,6-trimethylsilyl)methyl] A luminescent compound is added to a polymer compound such as PTAA. The light-emitting compound may be doped and used in the light-emitting layer. can be used.

[0299] <Substrate> Furthermore, the light-emitting element according to one embodiment of the present invention may be formed on a substrate made of glass, plastic, or the like. As for the order of fabrication on the substrate, the layers may be stacked in order from the electrode 101 side. They may be stacked in order from the pole 102 side.

[0300] The substrate on which the light-emitting element according to one embodiment of the present invention can be formed is, for example, glass or quartz. Alternatively, a flexible substrate may be used. The substrate is a flexible substrate, such as polycarbonate. Examples of suitable substrates include plastic substrates made of polyacrylate and polyarylate. It is also possible to use a metal-deposited film. Any other material may be used as long as it functions as a support in the light-emitting device. Anything that has the function of protecting the element and the optical element may be used.

[0301] For example, in one embodiment of the present invention, a light-emitting element can be formed using various substrates. The type of substrate is not particularly limited. An example of the substrate is a semiconductor substrate (e.g., Single crystal substrate or silicon substrate), SOI substrate, glass substrate, quartz substrate, plastic substrate , metal substrate, stainless steel substrate, substrate with stainless steel foil, Tungsten substrate, substrate with tungsten foil, flexible substrate, lamination film, These include cellulose nanofibers (CNF), paper, and base films that contain fibrous materials. Examples of glass substrates include barium borosilicate glass and aluminoborosilicate glass. , or soda lime glass. Flexible substrates, laminating films, base films Examples of such materials include polyethylene terephthalate (PET) ), polyethylene naphthalate (PEN), polyethersulfone (PES), polytetrafluoroethylene There are plastics such as tetrafluoroethylene (PTFE). Examples of the resin include acrylic resin. Polyvinyl fluoride, polyvinyl chloride, etc. Alternatively, for example, polyaniline Examples of the material include: aluminium, polyimide, aramid, epoxy, inorganic vapor deposition film, and paper.

[0302] Alternatively, a flexible substrate may be used as the substrate, and the light emitting element may be formed directly on the flexible substrate. Alternatively, a release layer may be provided between the substrate and the light-emitting element. After a part or all of a device is completed, it is separated from the substrate and used to transfer it to another substrate. In this case, the light emitting element can be transferred onto a substrate having poor heat resistance or a flexible substrate. The peeling layer may have a laminated structure of inorganic films, such as a tungsten film and a silicon oxide film. or a structure in which a resin film such as polyimide is formed on a substrate, etc., can be used.

[0303] That is, a light emitting element is formed using a certain substrate, and then the light emitting element is transferred to another substrate. The light emitting element may be disposed on another substrate. In addition to the substrates mentioned above, cellophane substrates, stone substrates, wood substrates, fabric substrates (natural fibers (silk, cotton, Hemp), synthetic fibers (nylon, polyurethane, polyester) or regenerated fibers (acetate (including cellulose, cupro, rayon, recycled polyester, etc.), leather substrate, rubber substrate, etc. By using these substrates, it is possible to produce light emitting elements that are durable and highly heat resistant. The light emitting element may be a small, lightweight, or thin light emitting element.

[0304] Furthermore, for example, a field effect transistor (FET) is formed on the above-mentioned substrate, and the FET and The light emitting element 150 may be fabricated on the electrically connected electrodes. In this way, an active matrix display device that controls the driving of light emitting elements can be manufactured.

[0305] As described above, the structure shown in this embodiment mode can be used in appropriate combination with other embodiment modes. Cut.

[0306] (Embodiment 2) In this embodiment, a compound having a structure similar to that of an organic compound which can be suitably used in a light-emitting element of one embodiment of the present invention will be described. An example of the synthesis method will be explained using organic compounds represented by general formulas (G1) and (G2) as examples. do.

[0307] <Method for synthesizing organic compound represented by general formula (G1)> The organic compound represented by the general formula (G1) can be synthesized by a synthesis method that applies various reactions. For example, the following synthesis schemes (S-1) and (S-2) can be used to It can be synthesized by combining Compound 1, an arylamine (Compound 2), and an arylamine ( By coupling with compound 3), a diamine compound (compound 4) is obtained.

[0308] Next, a diamine compound (compound 4), an aryl halide (compound 5), and a halogen By coupling with an aryl fluoride (compound 6), the compound represented by the above general formula (G1) can be obtained. Organic compounds can be obtained.

[0309] [ka]

[0310] [ka]

[0311] In the above synthesis schemes (S-1) and (S-2), A is a compound having 10 to 30 carbon atoms. or a substituted or unsubstituted condensed aromatic ring having 10 to 30 carbon atoms represents a heteroaromatic ring, and Ar 1 ~Ar 4 are each independently substituted or unsubstituted carbon atoms having 6 or more carbon atoms. represents an aromatic hydrocarbon group having a molecular weight of 1 to 13; 1 ~X 8 are each independently a group having 3 to 10 carbon atoms the alkyl groups listed below, substituted or unsubstituted cycloalkyl groups with 3 to 10 carbon atoms, The fused aromatic ring or fused aromatic ring represents any one of the trialkylsilyl groups having a number of 3 to 12. Heteroaromatic rings include chrysene, phenanthrene, stilbene, acridone, and phenoxa In particular, anthracene, pyrene, coumarin, quinacrine, Preferred are benzofuran, perylene, tetracene and naphthobisbenzofuran.

[0312] In the above synthesis schemes (S-1) and (S-2), When performing the Hubbard-Hartwig reaction, X 10 ~X 13 is a halogen group or a trifluoromethyl group The halogen is preferably iodine, bromine or chlorine. , bis(dibenzylideneacetone)palladium(0), palladium(II) acetate, etc. dium compounds and tri(tert-butyl)phosphine, tri(n-hexyl)phosphine phosphine, tricyclohexylphosphine, di(1-adamantyl)-n-butylphosphine, 2-dicyclohexylphosphino-2',6'-dimethoxy-1,1'-biphenyl, etc. In addition, organic bases such as sodium tert-butoxide and Inorganic bases such as potassium carbonate, cesium carbonate, and sodium carbonate can be used. In addition, the solvent may be toluene, xylene, mesitylene, benzene, tetrahydrofuran, Dioxane and the like can be used. The reagents that can be used in this reaction are The present invention is not limited to these reagents.

[0313] The reactions carried out in the above synthesis schemes (S-1) and (S-2) are carried out by Buchwald reaction. The Hartwig reaction is not limited to this, but also involves the use of organotin compounds such as Migita, Kosugi, and Stiegler. Coupling reaction using Grignard reagents, copper or copper compounds The Ullmann reaction, which was used in the previous method, can be used.

[0314] In the above synthesis scheme (S-1), when compound 2 and compound 3 have different structures, Compound 1 and compound 2 are first reacted to form a coupling product, and the resulting coupling product is It is preferable to react Compound 1 with Compound 3. When compound 3 is reacted stepwise, compound 1 is preferably a dihalogen compound, and X 10 and X 11 It is preferable to carry out the amination reaction selectively using different halogens one by one. I wish.

[0315] Furthermore, in the synthesis scheme (S-2), when compound 5 and compound 6 have different structures, Compound 4 and compound 5 are first reacted to obtain a coupling product, and then the resulting coupling product is further reacted with the compound 6 to obtain a coupling product. It is preferable to react the coupling product with compound 6.

[0316] <Method for synthesizing organic compound represented by general formula (G2)> The organic compound of one embodiment of the present invention represented by general formula (G2) can be obtained by utilizing any organic reaction. As examples, two methods are shown below.

[0317] The first method consists of the following synthesis schemes (S-3) to (S-8). In this step, the aniline compound (compound 7) and 1,4-cyclohexadiene-1,4-dicarboxamide The amine compound (compound 9) is obtained by the condensation reaction of the phosphate compound (compound 8). The scheme (S-3) shows the synthesis of aniline compounds (chemical compounds) with the same substituents in one step. When two compounds 7) are condensed to introduce amino groups having the same substituent, two equivalents of aniline are used. It is preferable to carry out the same reaction by adding a phosphorus compound (compound 7). The target product can be obtained even if the carbonyl group has no reaction selectivity.

[0318] Next, the amine compound (compound 9) and the aniline derivative (compound 10) are subjected to a condensation reaction. The 1,4-cyclohexadiene compound (compound 11) can be obtained by the above procedure. The process for obtaining the above is shown in Scheme (S-4).

[0319] Next, the 1,4-cyclohexadiene compound (compound 11) was oxidized in air. A terephthalic acid compound (compound 12) can be obtained by the following steps. is shown in Scheme (S-5).

[0320] Then, the terephthalic acid compound (compound 12) was subjected to ring condensation using an acid to give cinchona. A cridone compound (compound 13) can be obtained. The process for obtaining compound 13 is shown in Scheme ( S-6).

[0321] Next, the quinacridone compound (compound 13) and the aryl halide (compound 14) were mixed. By pulling, a quinacridone compound (compound 15) can be obtained. The process for obtaining compound 15 is shown in Scheme (S-7). Two aryl halides (compound 8) can be coupled to form a compound with the same substituent. To introduce an amino group, add two equivalents of aryl halide (compound 14) to the same amount. In this case, even if the amino group of compound 14 does not have reaction selectivity, You can get the desired result.

[0322] Next, the quinacridone compound (compound 15) and the aryl halide (compound 16) were mixed. By pulling, an organic compound represented by the above general formula (G2) can be obtained. The process is shown in Scheme (S-8).

[0323] [ka]

[0324] [ka]

[0325] The second method is shown in the synthetic schemes (S-3) to (S-5), (S-9) and (S-1) below. The explanation of (S-3) to (S-5) is as above. The terephthalic acid compound (compound 12) and the aryl halide (compound 14) were coupled. By ringing, a diamine compound (compound 17) can be obtained. The process for obtaining the above is shown in Scheme (S-9). Two aryl fluoride molecules can be coupled, and amino groups with identical substituents can be introduced. When aryl halide (compound 14) is added, the same reaction can be carried out by adding 2 equivalents of aryl halide. In this case, the target compound can be obtained even if the amino group of compound 12 does not have reaction selectivity.

[0326] Next, the diamine compound (compound 17) and the aryl halide (compound 16) were coupled. By this reaction, a diamine compound (compound 18) can be obtained. The process for obtaining this is shown in Scheme (S-10).

[0327] Finally, the diamine compound (compound 18) is subjected to ring condensation using an acid to obtain the compound of the general formula ( The organic compound represented by the formula (G2) can be obtained. The process is shown in Scheme (S-11). However, during the ring condensation reaction, Ar 5 or Ar 6 The hydrogen at the ortho position of the compound reacts to form the compound of the general formula ( Isomers of organic compounds represented by G2) may occur.

[0328] In scheme (S-11), a diamine compound (compound 18) having a symmetric structure is By using this, it is possible to synthesize an organic compound represented by the above general formula (G2).

[0329] [ka]

[0330] In the synthesis schemes (S-3) to (S-6) and (S-9) to (S-11), Al 1 represents an alkyl group such as a methyl group.

[0331] In the synthesis schemes (S-7) to (S-10), Y 1 and Y 2 are chlorine, bromine, iodine, represents a triflate group.

[0332] In the synthetic schemes (S-7) to (S-10), the reaction can be carried out at high temperatures. The Ullmann reaction is preferred because it allows the target compound to be obtained in a relatively high yield. The reagents that can be used in this reaction include copper or copper compounds, and the base is potassium carbonate. Inorganic bases that can be used in this reaction include methyl methyl ether, sodium hydride, etc. The solvent used is 2,2,6,6-tetramethyl-3,5-heptanedione, 1,3-dimethyl -3,4,5,6-tetrahydro-2(1H)pyrimidinone (DMPU), toluene, Examples of suitable amines include silane and benzene. In the Ullmann reaction, the reaction temperature should be 100°C or higher. The target product can be obtained in a short time and in high yield, so 2,2,6,6-tetramethyl It is preferable to use 3,5-heptanedione, DMPU, and xylene. Since the temperature is more preferably 150°C or higher, it is more preferable to use DMPU. The reagents that can be used in this reaction are not limited to the above-mentioned reagents. do not have.

[0333] In the synthesis schemes (S-7) to (S-10), Buchval reaction using a palladium catalyst The Hartwig reaction can be carried out in which bis(dibenzylidene acetonitrile) Palladium(0), palladium(II) acetate, [1,1-bis(diphenylphosphine palladium(II) dichloride, tetrakis(triphenylphosphine ) Palladium(0), allylpalladium(II) chloride (dimer), etc. and tri(tert-butyl)phosphine, tri(n-hexyl)phosphine, tri Cyclohexylphosphine, di(1-adamantyl)-n-butylphosphine, 2-dicyclohexyl Cyclohexylphosphino-2',6'-dimethoxybiphenyl, tri(ortho-tolyl) Phosphine, (S)-(6,6'-dimethoxybiphenyl-2,2'-diyl)bis(di isopropylphosphine (abbreviation: cBRIDP (registered trademark)) and other ligands can be used. In this reaction, an organic base such as sodium tert-butoxide or potassium carbonate is used. Inorganic bases such as ammonium carbonate, cesium carbonate, sodium carbonate, etc. can be used in this reaction. As a solvent, toluene, xylene, benzene, tetrahydrofuran, dioxane, etc. are used. The reagents that can be used in this reaction are not limited to the above-mentioned reagents. isn't it.

[0334] The method for synthesizing the organic compound represented by the general formula (G2) of the present invention is a synthetic scheme. The present invention is not limited to the above (S-1) to (S-11).

[0335] R substituted on the quinacridone skeleton 1 ~R 10 Specific examples of the group include an n-propyl group, an isopropyl group, and an isopropyl group. isopropyl group, n-butyl group, isobutyl group, tert-butyl group, cyclopropyl group, Cyclobutyl group, cyclopentyl group, cyclohexyl group, trimethylsilyl group, triethyl Examples include a silyl group and a tributylsilyl group.

[0336] X 9 and X 10 Substituted by Ar 5 and X 11 and X 12 Substituted by Ar 6 As a concrete example of is a 2-isopropylphenyl group, a 2-butylphenyl group, a 2-isobutylphenyl group, 2-tert-butylphenyl group, 2-isopropylphenyl group, 2-butylphenyl group , 3-propylphenyl group, 3-isobutylphenyl group, 3-tert-butylphenyl group, 4-propylphenyl group, 4-isopropylphenyl group, 4-butylphenyl group, 4 -isobutylphenyl group, 4-tert-butylphenyl group, 3,5-dipropylphenyl group phenyl group, 3,5-diisopropylphenyl group, 3,5-dibutylphenyl group, 3,5-diphenyl -isobutylphenyl group, (3,5-di-tert-butyl)phenyl group, 1,3-diphenyl propylphenyl group, 1,3-diisopropylphenyl group, 1,3-dibutylphenyl group , 1,3-di-isobutylphenyl group, (1,3-di-tert-butyl)phenyl group, 1,3,5-triisopropylphenyl group, (1,3,5-tri-tert-butyl)phenyl group Examples of the aryl group include a phenyl group and a 4-cyclohexylphenyl group.

[0337] As described above, the organic compounds represented by the general formula (G1) and the general formula (G2) are one embodiment of the present invention. However, the present invention is not limited to this, and other synthesis methods may be used. It may also be synthesized by

[0338] (Embodiment 3) In this embodiment mode, a light-emitting element having a different structure from that of the light-emitting element shown in Embodiment 1 is The following will be explained with reference to FIG. 7. In FIG. 7, the symbols shown in FIG. 1(A) Parts with the same function may be marked with the same hatch pattern and the reference numerals may be omitted. In addition, parts having similar functions are denoted by similar reference numerals, and detailed descriptions thereof may be omitted. There is a match.

[0339] <Configuration example 2 of light-emitting element> FIG. 7 is a schematic cross-sectional view of the light emitting element 250. As shown in FIG.

[0340] The light-emitting element 250 shown in FIG. 7 has a plurality of electrodes between a pair of electrodes (electrode 101 and electrode 102). The light-emitting unit 106 and the light-emitting unit 108 are light-emitting units. One of the light-emitting units in the unit is the same as the EL layer 100 shown in FIG. That is, the light emitting element 150 shown in FIG. It is preferable that the light emitting element 250 has a plurality of light emitting units. In the optical element 250, the electrode 101 functions as an anode and the electrode 102 functions as a cathode. However, the following description will be given assuming that the light emitting element 250 has the same structure as the light emitting element 250, and the structure of the light emitting element 250 may be reversed.

[0341] In addition, in the light-emitting element 250 shown in FIG. 7, the light-emitting unit 106 and the light-emitting unit 108 The light-emitting unit 106 and the light-emitting unit 108 are stacked together, and a charge generating layer 1 is provided between the light-emitting unit 106 and the light-emitting unit 108. The light-emitting units 106 and 108 may have the same configuration but different For example, the light-emitting unit 108 may have the same structure as the EL layer 100. This is preferable.

[0342] The light emitting element 250 has a light emitting layer 120 and a light emitting layer 170. In addition to the light-emitting layer 120, the knit 106 includes a hole injection layer 111, a hole transport layer 112, an electron transport layer The light-emitting unit 108 also includes an emissive layer 170. In addition to the above, a hole injection layer 116, a hole transport layer 117, an electron transport layer 118, and an electron injection layer 11 It has 9.

[0343] The light-emitting element 250 has the following structure in any of the layers of the light-emitting unit 106 and the light-emitting unit 108. It is sufficient that the compound according to one embodiment of the present invention is contained. Preferably, it is the light-emitting layer 120 or the light-emitting layer 170.

[0344] The charge generation layer 115 is formed by adding an acceptor material, which is an electron acceptor, to a hole transport material. Even if the electron transport material is an electron donor, a donor material may be added to the electron transport material. Alternatively, both of these structures may be stacked.

[0345] When the charge generation layer 115 contains a composite material of an organic compound and an acceptor substance, the The composite material that can be used for the hole-injection layer 111 shown in Embodiment 1 is used as the composite material. The organic compounds include aromatic amine compounds, carbazole compounds, aromatic carbonized compounds, and the like. Various compounds such as hydrogen and polymer compounds (oligomers, dendrimers, polymers, etc.) are used. As for organic compounds, those with a hole mobility of 1×10 -6 cm 2 / Vs However, it is preferable to use a material having a higher hole transporting property than an electron transporting property. Other materials may be used as long as they are compatible with the organic compound and the acceptor material. The material has excellent carrier injection and carrier transport properties, allowing for low voltage and low current operation. In addition, the anode side of the light-emitting unit is in contact with the charge generating layer 115. In this case, the charge generation layer 115 also serves as a hole injection layer or a hole transport layer for the light-emitting unit. Therefore, the light-emitting unit does not need to have a hole injection layer or a hole transport layer. Alternatively, when the cathode side surface of the light-emitting unit is in contact with the charge generating layer 115, The charge generation layer 115 also serves as an electron injection layer or an electron transport layer for the light-emitting unit. Therefore, the light-emitting unit does not have an electron injection layer or an electron transport layer. is also good.

[0346] The charge generation layer 115 may be a layer containing a composite material of an organic compound and an acceptor substance, or another layer containing a compound of an organic compound and an acceptor substance. For example, the organic EL element may be formed as a laminated structure in which layers made of the organic EL element are combined. A layer including a composite material of a compound and an acceptor substance and a layer including a compound selected from electron donor substances. The compound may be formed by combining a layer containing the compound with a compound having a high electron transporting property. A layer containing a composite material of an organic compound and an acceptor substance and a layer containing a transparent conductive film are combined. It may be formed by combining the above.

[0347] The charge generating layer 115 sandwiched between the light emitting unit 106 and the light emitting unit 108 When a voltage is applied between the electrode 101 and the electrode 102, electrons are injected into one of the light-emitting units, It is sufficient if it injects holes into the other light-emitting unit. For example, in FIG. When a voltage is applied so that the potential of electrode 101 is higher than the potential of electrode 102, charge generation Layer 115 injects electrons into light-emitting unit 106 and holes into light-emitting unit 108. .

[0348] From the viewpoint of light extraction efficiency, the charge generation layer 115 is transparent to visible light (specifically, It is preferable that the charge generating layer 115 has a visible light transmittance of 40% or more. The charge generating layer 115 has a lower conductivity than the pair of electrodes (electrodes 101 and 102). It still works.

[0349] By forming the charge generating layer 115 using the above-mentioned materials, when a light emitting layer is laminated, In this case, the increase in the driving voltage can be suppressed.

[0350] In addition, although the light emitting element having two light emitting units has been described with reference to FIG. 7, the light emitting element having three light emitting units may be The same can be applied to a light-emitting element in which two or more light-emitting units are stacked. As shown in the light-emitting element 250, a plurality of light-emitting units are separated by a charge generating layer between a pair of electrodes. By arranging the LEDs in this way, high brightness light emission is possible while keeping the current density low, and furthermore, a long life is achieved. Furthermore, a light-emitting element with low power consumption can be realized.

[0351] In each of the above configurations, the gates used in the light-emitting units 106 and 108 The light emitting colors of the light emitting materials may be the same or different. The guest unit 106 and the light-emitting unit 108 have the function of emitting light of the same color. When the material is included, the light emitting element 250 becomes a light emitting element that exhibits high light emitting luminance with a small current value. It is more preferable that the light-emitting units 106 and 108 emit light of different colors. When the light-emitting element 250 includes a guest material having a light-emitting function, the light-emitting element 250 can emit multicolor light. In this case, either one of the light-emitting layer 120 and the light-emitting layer 170 or In both cases, the light emitting element 250 is formed by using a plurality of light emitting materials with different emission wavelengths. The emission spectrum is a composite of light with different emission peaks, so Both result in an emission spectrum with two maxima.

[0352] The above-mentioned structure is also suitable for obtaining white light emission. By making the lights complementary to each other, white light can be emitted. The resulting white light is highly luminescent, or at least has red, green, and blue components. It is preferable to select a suitable material.

[0353] The light-emitting layer 130 shown in the first embodiment may be formed in one or both of the light-emitting layers 120 and 170. By using this configuration, it is possible to obtain light emitting devices with good luminous efficiency and reliability. The guest material contained in the light-emitting layer 130 is a fluorescent material. Therefore, the light-emitting layer 120 and / or the light-emitting layer 170 may be formed using the light-emitting layer 1 shown in the first embodiment. By using the structure of 30, a light-emitting element with high efficiency and high reliability can be obtained.

[0354] In addition, in the case of a light-emitting element in which three or more light-emitting units are stacked, the The guest materials may emit light of the same color or different colors. In the case where a plurality of light-emitting units are included, the emitted colors of the light emitted by the plurality of light-emitting units are Compared to other colors, high luminance can be obtained with a small current value. The composition can be suitably used to adjust the luminous color. This is suitable when using a guest material that exhibits a luminescent color. For example, In this case, two light-emitting units having fluorescent materials of the same color are arranged in layers, and two light-emitting units having fluorescent materials of different colors are arranged in layers. By arranging the light-emitting unit containing colored phosphorescent materials in a single layer, it is possible to emit both fluorescent and phosphorescent light. The light intensity can be adjusted by adjusting the number of light-emitting units. It is possible to adjust it.

[0355] In the case of a light-emitting device having two layers of such fluorescent light-emitting units and one layer of phosphorescent light-emitting unit, blue Contains two layers of light-emitting units containing color fluorescent materials and one layer of light-emitting unit containing yellow phosphorescent material a light-emitting element including two layers of light-emitting units containing a blue fluorescent material, and a light-emitting element including a red phosphorescent material and a green phosphorescent material; a light-emitting element having one layer of a light-emitting unit containing a blue fluorescent material; and one layer of a light-emitting unit including a red phosphorescent material, a yellow phosphorescent material, and a green phosphorescent material. In this case, the light emitting element is preferably an optical element, since white light can be efficiently emitted. The light-emitting element can be appropriately combined with a phosphorescent light-emitting unit.

[0356] Furthermore, the phosphorescent light-emitting unit emits light of a color other than blue. As an example, the structure of the light-emitting layer 130 shown in Embodiment 1 can be used. The light-emitting units other than blue light-emitting units contain fluorescent materials. For example, A light-emitting element including two layers of knit and one layer of a light-emitting unit containing a yellow fluorescent material, Two light-emitting units containing red and green fluorescent materials are arranged in a single layer. A light-emitting device having one layer of a light-emitting unit containing a blue fluorescent material, or two layers of a light-emitting unit containing a red fluorescent material A light-emitting device having one layer of a light-emitting unit including a material, a yellow fluorescent material, and a green fluorescent material is considered. In this case, among the light-emitting units of the light-emitting element, the light-emitting element that emits light other than blue light may be In the case of the combination of the above light-emitting units, the red, green, and yellow light-emitting units are used in the embodiment. It is also possible to use the configuration of the light-emitting layer 130 shown in Embodiment 1. In this case, the light-emitting layer of the blue fluorescent light-emitting unit is preferably The following materials can be used for the light-emitting layer of the blue fluorescent light-emitting unit. The relationship between the T1 level of the host material and the T1 level of the guest material is as follows: T1 level of the host material < When the T1 level of the guest material is reached, triplet-triplet annihilation (TTA) occurs. This is preferable because it is expected to be highly efficient due to the use of acetone annihilation. Of course, the configuration of the light-emitting layer 130 shown in the first embodiment may also be used for the blue fluorescent light-emitting unit. do not have.

[0357] In addition, at least one of the light-emitting layer 120 and the light-emitting layer 170 is further divided into layers, Each divided layer may contain a different light-emitting material. Alternatively, at least one of the light-emitting layers 170 may be composed of two or more layers. For example, the first light-emitting layer and the second light-emitting layer can be laminated in this order from the hole transport layer side to form the light-emitting layer. In this case, a material having hole transport properties is used as the host material of the first light-emitting layer, and a material having hole transport properties is used as the host material of the second light-emitting layer. In this case, a material having an electron transporting property is used as the host material. The light-emitting material contained in the light-emitting layer and the second light-emitting layer may be the same material or different materials. Even if a material has the function of emitting light of the same color, it may have the function of emitting light of different colors. A plurality of light-emitting materials each having the function of emitting light of a different color may be used. By using this configuration, it is possible to obtain white light with high color rendering properties that is composed of three primary colors or four or more luminescent colors. It is also possible.

[0358] The light-emitting layer of the phosphorescent light-emitting unit described in the third embodiment includes the hole transport layer described in the first embodiment. An appropriate combination of an electron transporting material, an electron transporting material, and a phosphorescent material can be used.

[0359] The host material and guest material used in the light-emitting layer of the above-mentioned blue fluorescent light-emitting unit are There are no particular limitations on the materials, but examples include the following:

[0360] As the guest material, for example, a pyrene derivative, a perylene derivative, etc. can be used. For example, the following materials can be used:

[0361] Specifically, N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-phenyl)- [Fluoren-9-yl]phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPr n), N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl- 9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mM emFLPAPrn), N,N'-bis[4-(9-phenyl-9H-fluorene-9- -N,N'-bis(4-tert-butylphenyl)-pyrene-1,6 -diamine (abbreviation: 1,6tBu-FLPAPrn), N,N'-bis[4-(9-phenyl N,N'-diphenyl-3,8-diphenyl-9H-fluoren-9-ylphenyl Cyclohexylpyrene-1,6-diamine (abbreviation: ch-1,6FLPAPrn), 5,1 0,15,20-Tetraphenylbisbenzo[5,6]indeno[1,2,3-cd:1 ',2',3'-lm]perylene, etc.

[0362] Examples of the host material include anthracene derivatives, phenanthrene derivatives, and pyrene derivatives. condensed polycyclic aromatic compounds such as chrysene derivatives, dibenzo[g,p]chrysene derivatives, etc. Specifically, tris(8-quinolinolato)aluminum(III) (abbreviation: A lq), tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Al mq3), bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation :BeBq2), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)a Aluminum(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq), bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation :ZnPBO), bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation ZnBTZ), 2-(4-biphenylyl)-5-(4-tert-butyl) phenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-( p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 3-(4-biphenylyl)-4-phenyl-5-(4-tert -butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 2,2',2''- (1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), bathophenanthroline (abbreviation: BPhen), bathocuproine ( Abbreviation: BCP), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl )phenyl]-9H-carbazole (abbreviation: CO11), and other heterocyclic compounds, Bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB or α -NPD), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1 '-biphenyl]-4,4'-diamine (abbreviation: TPD), 4,4'-bis[N-(spiro[ (B,B-9,9'-bifluoren-2-yl)-N-phenylamino]biphenyl Aromatic amine compounds such as SPB are also included. Thylene derivatives, pyrene derivatives, chrysene derivatives, dibenzo[g,p]chrysene derivatives, etc. Condensed polycyclic aromatic compounds include 9,10-diphenylanthracene (abbreviated as 9,10-diphenylanthracene). Name: DPAnth), N,N-diphenyl-9-[4-(10-phenyl-9-anthri phenyl]-9H-carbazol-3-amine (abbreviation: CzA1PA), 4-(10 -phenyl-9-anthryl)triphenylamine (abbreviation: DPhPA), 4-(9H- Carbazol-9-yl)-4'-(10-phenyl-9-anthryl)triphenyl amine (abbreviation: YGAPA), N,9-diphenyl-N-[4-(10-phenyl-9-a N,9(triphenyl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA) -diphenyl-N-{4-[4-(10-phenyl-9-anthryl)phenyl]phenyl N,9-diphenyl- N-(9,10-diphenyl-2-anthryl)-9H-carbazol-3-amine (abbreviation Name: 2PCAPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H -Dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 6,12-dimethoxy -5,11-diphenylchrysene, N,N,N',N',N'',N'',N''',N '''-Octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetraamine DBC1, 9-phenyl-3-[4-(10-phenyl-9-anthryl) phenyl]-9H-carbazole (abbreviation: PCzPA), 3,6-diphenyl-9-[4 -(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: DPC zPA), 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPP A), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 2-tert-butyl t-BuDNA, 9,9'-di-9,10-di(2-naphthyl)anthracene -Bianthryl (abbreviation: BANT), 9,9'-(stilbene-3,3'-diyl)diphenyl Phenanthrene (abbreviation: DPNS), 9,9'-(stilbene-4,4'-diyl)diphenanthren Nanthrene (abbreviation: DPNS2), 1,3,5-tri(1-pyrenyl)benzene (abbreviation: Among these and other known substances, the above-mentioned gues A material with an energy gap larger than that of the target material is called a A plurality of types may be selected and used.

[0363] Note that this embodiment mode can be combined with other embodiment modes as appropriate.

[0364] (Fourth embodiment) In this embodiment mode, a light-emitting device using the light-emitting element described in Embodiment Mode 1 and Embodiment Mode 3 is This will be explained with reference to FIG. 8(A) and FIG. 8(B).

[0365] FIG. 8(A) is a top view showing a light-emitting device, and FIG. 8(B) is a cross-sectional view of FIG. 8(A) taken along lines AB and CD. This light emitting device is a cross-sectional view of a light emitting element. The illustrated drive circuit section (source side drive circuit) 601, pixel section 602, drive circuit section (gate side The driving circuit 603 is also included. 604 is a sealing substrate, 625 is a desiccant, and 605 is a shielding material. The inside surrounded by the sealing material 605 is a space 607 .

[0366] The lead wiring 608 is connected to the source side driver circuit 601 and the gate side driver circuit 603. The wiring is for transmitting signals, and the FPC (flexible printed circuit board) is the external input terminal. Video signal, clock signal, start signal, reset signal, etc. from the input circuit 609 Although only the FPC is shown here, this FPC has a printed wiring board. Even if a printed wiring board (PWB) is installed The light emitting device in this specification includes not only the light emitting device itself but also an FPC or This includes the state where the PWB is installed.

[0367] Next, a cross-sectional structure of the light emitting device will be described with reference to FIG. The driving circuit section and the pixel section are formed in the pixel section. A circuit 601 and one pixel in a pixel portion 602 are shown.

[0368] The source side driver circuit 601 includes an n-channel TFT 623 and a p-channel TFT 624. The drive circuit is a CMOS circuit that combines various CMOS circuits, P It may be formed of a MOS circuit or an NMOS circuit. Although this shows a driver integrated type in which the driver circuit is formed on the board, this is not necessarily required. It can also be formed externally.

[0369] The pixel section 602 includes a switching TFT 611, a current control TFT 612, and its drain. The pixel includes a first electrode 613 electrically connected to the first An insulator 614 is formed to cover the end of the electrode 613. It can be formed by using a photosensitive resin film of a mold.

[0370] In addition, in order to improve the coverage of the film formed on the insulator 614, The upper end or the lower end of the insulator 614 is formed to have a curved surface. When photosensitive acrylic is used as the material, it is possible to make only the upper end of the insulator 614 curved. The radius of curvature of the curved surface is preferably 0.2 μm or more and 0.3 μm or less. The border 614 may be either a negative or positive photosensitive material.

[0371] An EL layer 616 and a second electrode 617 are formed on the first electrode 613. Here, the material used for the first electrode 613 functioning as an anode is a material having a work function of It is desirable to use a large material, for example, an ITO film or an indium-silicon-containing film. Indium tin oxide film, indium oxide film containing 2wt% to 20wt% zinc oxide, nitride In addition to single layer films such as titanium film, chromium film, tungsten film, Zn film, and Pt film, titanium nitride film and Lamination with a film mainly composed of aluminum, titanium nitride film and a film mainly composed of aluminum A three-layer structure of a titanium nitride film and a silicon dioxide film can be used. The resistance is low, good ohmic contact can be achieved, and it can also function as an anode. This can be done.

[0372] The EL layer 616 can be formed by a deposition method using a deposition mask, an inkjet method, or a spin coating method. The EL layer 616 can be formed by various methods such as the above. The polymer may be a polymer or a polymer compound (including an oligomer or a dendrimer).

[0373] Furthermore, a material used for the second electrode 617 formed on the EL layer 616 and functioning as a cathode As the material, materials with a small work function (Al, Mg, Li, Ca, or their alloys or compounds) It is preferable to use a material such as MgAg, MgIn, or AlLi. When the generated light is transmitted through the second electrode 617, the second electrode 617 is formed with a thin film. Thin metal films and transparent conductive films (ITO, containing 2 wt% to 20 wt% zinc oxide) Indium oxide, silicon-containing indium tin oxide, zinc oxide (ZnO), etc. It is better to use layers.

[0374] The first electrode 613, the EL layer 616, and the second electrode 617 form a light-emitting element 618. The light emitting element 618 is a light emitting element having the configurations of the first and second embodiments. It is preferable that the pixel portion is formed with a plurality of light emitting elements. In the light emitting device of the present embodiment, a light emitting device having the configuration described in the first and second embodiments is used. The light-emitting element may include both a light-emitting element and a light-emitting element having other configurations.

[0375] Furthermore, the sealing substrate 604 is bonded to the element substrate 610 with a sealing material 605. A light emitting element is disposed in a space 607 surrounded by a sub-substrate 610, a sealing substrate 604, and a sealing material 605. 618 is provided. The space 607 is filled with a filler. In addition to cases where inert gas (nitrogen, argon, etc.) is filled, resin or desiccant or its Sometimes it is filled with both.

[0376] It is preferable to use epoxy resin or glass frit for the sealing material 605. It is desirable that these materials be as impermeable to moisture and oxygen as possible. Materials used for the sealing substrate 604 include glass substrates, quartz substrates, and FRP (Fiber Reinforced Plastics). reinforced plastics), PVF (polyvinyl fluoride), polyester A plastic substrate made of polyethylene or acrylic can be used.

[0377] As described above, the light-emitting device using the light-emitting elements described in the first and third embodiments can be obtained.

[0378] <Configuration example 1 of light-emitting device> FIG. 9 shows an example of a light-emitting device in which a light-emitting element that emits white light is formed and a coloring layer (color filter) is formed. An example of a light emitting device in which a light emitting diode (LED) filter is formed is shown.

[0379] FIG. 9A shows a substrate 1001, an underlying insulating film 1002, a gate insulating film 1003, and a gate electrode. 1006, 1007, 1008, a first interlayer insulating film 1020, and a second interlayer insulating film 1021 , a peripheral portion 1042, a pixel portion 1040, a driving circuit portion 1041, and a first electrode 102 of the light-emitting element. 4W, 1024R, 1024G, 1024B, partition 1026, EL layer 1028, light-emitting element The second electrode 1029, the sealing substrate 1031, the sealing material 1032, the red pixel 1044R, the green Color pixels 1044G, blue pixels 1044B, white pixels 1044W, etc. are shown.

[0380] 9(A) and 9(B) show colored layers (red colored layer 1034R, green colored layer 10 34G, blue colored layer 1034B) is provided on the transparent substrate 1033. A black matrix 1035 may be further provided. The transparent substrate 1033 is aligned and fixed to the substrate 1001. The color layer is covered with an overcoat layer 1036. In FIG. 9(A), the light The light-emitting layer emits light to the outside without passing through the colored layer, and the light-emitting layer emits light to the outside by passing through the colored layer of each color. The light that does not pass through the colored layer is white, and the light that passes through the colored layer is red, blue, or green. This allows images to be expressed using four color pixels.

[0381] In FIG. 9B, a red colored layer 1034R, a green colored layer 1034G, and a blue colored layer 103 4B is formed between the gate insulating film 1003 and the first interlayer insulating film 1020. As shown in FIG. 9(B), the colored layer may be provided between the substrate 1001 and the sealing substrate 1031. stomach.

[0382] In the light emitting device described above, light is taken in toward the substrate 1001 on which the TFT is formed. The light emitting device has a bottom emission structure, but the light is taken in from the sealing substrate 1031 side. The light emitting device may have a top emission structure.

[0383] <Configuration Example 2 of Light-Emitting Device> Cross-sectional views of a top-emission type light-emitting device are shown in FIGS. 10(A) and 10(B). In this case, the substrate 1001 can be a substrate that does not transmit light. The process is the same as that of a bottom emission type light emitting device until a connection electrode for connecting the Thereafter, a third interlayer insulating film 1037 is formed to cover the electrode 1022. The third interlayer insulating film 1037 may have a flattening function. In addition to the same material as 21, various other materials can be used.

[0384] The lower electrode 1025W, the lower electrode 1025R, the lower electrode 1025G, and the lower electrode 1 Although 025B is an anode here, it may be a cathode. In the case of a top-emission type light-emitting device such as 10(B), the lower electrode 1025W, The lower electrode 1025R, the lower electrode 1025G, and the lower electrode 1025B can be reflective electrodes. It is preferable that the second electrode 1029 has a function of reflecting light and a function of transmitting light. In addition, the second electrode 1029, the lower electrode 1025W, the lower electrode 1025R, and the lower A microcavity structure is applied between the upper electrode 1025G and the lower electrode 1025B to generate a specific wave. It is preferable that the EL layer 1028 has a function of amplifying long-wave light. The device has the same configuration as that described in the third embodiment and has an element structure that can emit white light.

[0385] In Figures 9(A), 9(B), 10(A) and 10(B), white light is obtained. The EL layer may be configured to have a plurality of light-emitting layers or a plurality of light-emitting units. However, the configuration for obtaining white light emission is not limited to these.

[0386] In the top emission structure shown in Fig. 10(A) and Fig. 10(B), a colored layer (red colored layer) a green colored layer 1034R, a green colored layer 1034G, and a blue colored layer 1034B) on the sealing substrate 1 The sealing substrate 1031 is provided with a layer of a conductive film disposed between pixels. A black layer (black matrix) 1030 may be provided as shown in FIG. 034R, green colored layer 1034G, blue colored layer 1034B) and black layer (black mat The transparent substrate 1031 may be covered with an overcoat layer. A substrate having optical properties is used.

[0387] In addition, although FIG. 10(A) shows a configuration for full color display using three colors, red, green, and blue, As shown in Fig. 0(B), a full color display using four colors, red, green, blue, and white, may also be performed. In addition, the full-color display configuration is not limited to these. For example, red, green, blue, yellow, A full color display may be performed using these four colors.

[0388] A light-emitting element according to one embodiment of the present invention uses a fluorescent material as a guest material. Compared to phosphorescent materials, the spectrum is sharper, making it possible to obtain light emission with high color purity. Therefore, by using the light-emitting element in the light-emitting device described in this embodiment mode, color reproduction can be achieved. A highly efficient light emitting device can be obtained.

[0389] As described above, the light-emitting device using the light-emitting elements described in the first and third embodiments can be obtained.

[0390] Note that this embodiment mode can be combined with other embodiment modes as appropriate.

[0391] (Embodiment 5) In this embodiment, an electronic device and a display device according to one embodiment of the present invention will be described.

[0392] According to one embodiment of the present invention, a highly reliable electronic device and display device having a flat surface and high light emission efficiency can be provided. Furthermore, according to one embodiment of the present invention, a display device having a curved surface and high light emission efficiency can be manufactured. In addition, as described above, it is possible to manufacture highly reliable electronic devices and display devices. The element can be obtained.

[0393] Examples of electronic devices include television sets, desktop or notebook PCs, etc. Personal computers, computer monitors, digital cameras, digital video cameras Cameras, digital photo frames, mobile phones, portable game consoles, personal digital assistants, sound reproduction Examples include large gaming machines such as pachinko machines.

[0394] The mobile information terminal 900 shown in FIGS. 11A and 11B includes a housing 901, a housing 902, a display unit 9 03, and a hinge portion 905.

[0395] The housing 901 and the housing 902 are connected by a hinge portion 905. The mobile information terminal 900 includes: It can be unfolded from the folded state (Fig. 11(A)) as shown in Fig. 11(B). This makes it highly portable when you are carrying it around, and it has a large display area when you are using it. , and has excellent visibility.

[0396] The portable information terminal 900 has a hinge 905 that connects the housing 901 and the housing 902. A flexible display unit 903 is provided.

[0397] The light-emitting device manufactured according to one embodiment of the present invention can be used in the display portion 903. This makes it possible to manufacture a highly reliable portable information terminal.

[0398] The display unit 903 can display at least one of document information, still images, and moving images. When document information is displayed on the display unit, the portable information terminal 900 is used as an electronic book terminal. It can be used as follows.

[0399] When the portable information terminal 900 is unfolded, the display unit 903 is held in a state where the radius of curvature is large. For example, the radius of curvature is 1 mm or more and 50 mm or less, preferably 5 mm or more and 30 mm or less. The display unit 903 is held by the housing 901 and the other parts of the display unit 903. Pixels are arranged continuously across the body 902, allowing curved surface display.

[0400] The display unit 903 functions as a touch panel and can be operated with a finger or a stylus. can.

[0401] The display unit 903 is preferably configured as a single flexible display. This allows for continuous, uninterrupted display between the housing 901 and the housing 902. It should be noted that the housing 901 and the housing 902 each have a display. You may do so.

[0402] The hinge portion 905 is a part that connects the housing 901 and the housing 902 when the mobile information terminal 900 is unfolded. It is preferable to have a locking mechanism to prevent the angle from becoming larger than a predetermined angle. For example, the angle at which the door will lock (will not open any further) must be between 90 degrees and 180 degrees. Typically, the angle is 90 degrees, 120 degrees, 135 degrees, 150 degrees, or 17 degrees. 5 degrees, etc. This improves the convenience, safety, and Reliability can be improved.

[0403] If the hinge part 905 has a locking mechanism, the display part 903 can be opened without applying excessive force. Therefore, it is possible to prevent the display unit 903 from being damaged. It can be achieved.

[0404] The housing 901 and the housing 902 are provided with a power button, an operation button, an external connection port, a speaker, a microphone, and the like. It may have a ridge or the like.

[0405] A wireless communication module is provided in either the housing 901 or the housing 902. Internet, LAN (Local Area Network), Wi-Fi (registered trademark) ) and can send and receive data over computer networks.

[0406] A portable information terminal 910 shown in FIG. 11C includes a housing 911, a display unit 912, and operation buttons 91. 3, an external connection port 914, a speaker 915, a microphone 916, a camera 917, etc.

[0407] The light-emitting device manufactured according to one embodiment of the present invention can be used in the display portion 912. This allows the production of portable information terminals with a high yield.

[0408] The mobile information terminal 910 has a touch sensor on the display unit 912. All operations, such as entering text, can be performed by touching the display 912 with a finger or a stylus. It can be done.

[0409] In addition, by operating the operation button 913, the power can be turned on and off, and the display on the display unit 912 can be changed. For example, you can change the type of image displayed from the main screen of the email composition screen. You can switch to the menu screen.

[0410] In addition, a detection device such as a gyro sensor or an acceleration sensor is installed inside the portable information terminal 910. By providing this, the orientation (portrait or landscape) of the mobile information terminal 910 can be determined and the screen of the display unit 912 can be displayed. The display orientation can be automatically switched. The input is made by touching the display 912, operating the operation button 913, or by voice input using the microphone 916. It can also be done by force or the like.

[0411] The mobile information terminal 910 is, for example, one or more devices selected from a telephone, a notebook, an information viewing device, etc. It has multiple functions. Specifically, it can be used as a smartphone. The information terminal 910 can be used for, for example, mobile phone calls, e-mails, viewing and creating documents, playing music, and watching videos. It can run various applications such as playback, internet communication, and games. do.

[0412] The camera 920 shown in FIG. 11(D) includes a housing 921, a display unit 922, an operation button 923, and a shutter. The camera 920 also has a shutter button 924. The camera 920 also has a detachable lens 926. It is attached.

[0413] The light-emitting device manufactured according to one embodiment of the present invention can be used in the display portion 922. This makes it possible to manufacture a highly reliable camera.

[0414] Here, the camera 920 and the lens 926 can be removed from the housing 921 and replaced. However, the lens 926 and the housing 921 may be integrated.

[0415] The camera 920 captures still or moving images by pressing the shutter button 924. The display unit 922 also has a function as a touch panel. It is also possible to take a picture by touching

[0416] The camera 920 can be equipped with a strobe device, a viewfinder, etc. Alternatively, these may be incorporated into the housing 921.

[0417] FIG. 12(A) is a schematic diagram showing an example of a cleaning robot.

[0418] The cleaning robot 5100 has a display 5101 on the top surface and multiple The camera 5102, the brush 5103, and the operation button 5104 are also shown. However, the underside of the cleaning robot 5100 is provided with tires, a suction port, etc. The robot 5100 also has an infrared sensor, an ultrasonic sensor, an acceleration sensor, a piezo sensor, It is equipped with various sensors such as a sensor, a light sensor, and a gyro sensor. 100 is equipped with wireless communication means.

[0419] The cleaning robot 5100 moves by itself, detects the dust 5120, and sucks it out from the suction port on the bottom. It can suck up dirt.

[0420] In addition, the cleaning robot 5100 analyzes the image captured by the camera 5102 and detects the wall, furniture, or It can detect obstacles such as steps. Image analysis can also detect obstacles such as wiring. If an object that may get tangled in the brush 5103 is detected, the rotation of the brush 5103 can be stopped. can.

[0421] The display 5101 can display the remaining battery level and the amount of dust sucked. The route traveled by the cleaning robot 5100 can be displayed on the display 5101. In addition, the display 5101 is a touch panel, and the operation button 5104 is It may be provided in the ray 5101.

[0422] The cleaning robot 5100 can communicate with a portable electronic device 5140 such as a smartphone. The images captured by the camera 5102 can be displayed on the portable electronic device 5140. Therefore, the owner of the Cleaning Robot 5100 can check the status of the room even when he is away from home. In addition, the display on the display 5101 can be displayed on a mobile electronic device such as a smartphone. You can also check it at 5140.

[0423] The light-emitting device according to one embodiment of the present invention can be used for the display 5101 .

[0424] The robot 2100 shown in FIG. 12(B) includes a computing device 2110, an illuminance sensor 2101, a microphone, and a microphone array. A microphone 2102, an upper camera 2103, a speaker 2104, a display 2105, It is equipped with a lower camera 2106, an obstacle sensor 2107, and a movement mechanism 2108.

[0425] The microphone 2102 has a function of detecting the user's voice and environmental sounds. The speaker 2104 has a function of emitting sound. The device 2102 and the speaker 2104 can be used to communicate with the user. It is possible.

[0426] The display 2105 has the function of displaying various information. Any information desired by the user can be displayed on the display 2105. The display 2105 may be equipped with a touch panel. It may be an information terminal that can be charged by placing it in a fixed position on the robot 2100. and enables data transfer.

[0427] The upper camera 2103 and the lower camera 2106 are used to capture images of the surroundings of the robot 2100. The obstacle sensor 2107 detects the obstacles in the robot 210 by using the moving mechanism 2108. When moving forward, the robot can sense whether there are any obstacles in its path. 00 uses an upper camera 2103, a lower camera 2106, and an obstacle sensor 2107. It is possible to recognize the surrounding environment and move safely.

[0428] The light-emitting device according to one embodiment of the present invention can be used for the display 2105 .

[0429] Fig. 12(C) is a diagram showing an example of a goggle-type display. For example, the device includes a housing 5000, a display unit 5001, a speaker 5003, an LED lamp 5004, , operation keys 5005 (including a power switch or an operation switch), a connection terminal 5006, Sensor 5007 (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, Temperature, chemicals, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient (including functions for measuring temperature, vibration, smell, or infrared rays), microphone 5008, It includes a second display portion 5002, a support portion 5012, earphones 5013, and the like.

[0430] The light-emitting device of one embodiment of the present invention can be used for the display portion 5001 and the second display portion 5002. can.

[0431] 13(A) and (B) show a foldable mobile information terminal 5150. The foldable mobile information terminal 5150 includes a housing 5151, a display area 5152, and a bending portion 515 13(A) shows the mobile information terminal 5150 in an unfolded state. Fig. 5B) shows the portable information terminal 5150 in a folded state. Although it has a large display area 5152, it is compact and highly portable when folded.

[0432] The display area 5152 can be folded in half by the bend 5153. 3 is composed of an expandable member and multiple support members, and when folding, The member is stretched, and the bent portion 5153 has a radius of curvature of 2 mm or more, preferably 5 mm or more. It can be folded.

[0433] The display area 5152 is a touch panel (input / output) equipped with a touch sensor (input device). The light-emitting device of one embodiment of the present invention can be used in the display region 5152. Cut.

[0434] This embodiment mode can be combined with other embodiment modes as appropriate.

[0435] (Embodiment 6) In this embodiment, an example in which the light-emitting element of one embodiment of the present invention is applied to various lighting devices will be described. 14. By using a light-emitting element which is one embodiment of the present invention, the light-emitting efficiency Therefore, a highly reliable lighting device can be manufactured.

[0436] By fabricating the light-emitting element of one embodiment of the present invention over a flexible substrate, it is possible to fabricate a light-emitting element having a curved surface. Electronic devices and lighting devices having light-emitting regions can be realized.

[0437] Furthermore, a light-emitting device using a light-emitting element according to one embodiment of the present invention can be used for automobile lighting. For example, lighting can be installed on the windshield, ceiling, etc.

[0438] FIG. 14 shows an example in which the light-emitting element is used as an indoor lighting device 8501. Since the surface area can be increased, a large-area lighting device can be formed. By using a housing having the above structure, a lighting device 8502 having a curved light-emitting area can be formed. The light-emitting element shown in this embodiment mode has a thin film shape, and the housing can be designed with a high degree of freedom. Therefore, it is possible to create lighting devices with various elaborate designs. A large lighting device 8503 may be provided on the wall. A touch sensor may be provided in 503 to turn the power on or off.

[0439] In addition, by using light-emitting elements on the surface of the table, it has the function of a table. The lighting device 8504 can be used as a lighting device. This allows the lighting device to function as furniture.

[0440] In this manner, a lighting device and an electronic device can be obtained by applying a light-emitting element of one embodiment of the present invention. Note that the lighting devices and electronic devices to which the present invention can be applied are the same as those described in this embodiment. The present invention can be applied to lighting devices and electronic devices in a wide range of fields.

[0441] The structure described in this embodiment mode may be used in appropriate combination with structures described in other embodiments. You can be there. [Example]

[0442] In this example, an organic compound represented by the structural formula (100) of Embodiment 1, 2-tert- Butyl-N,N,N',N'-tetrakis(4-tert-butylphenyl)-9,10 -Method for synthesizing anthracene diamine (abbreviation: 2tBu-ptBuDPhA2Anth) The present compound can be suitably used in the light-emitting element of one embodiment of the present invention. The guest material has a protecting group.

[0443] 1.2 g (3.1 mmol) of 2-tert-butylanthracene and 1.8 g (6.4 mmol) bis(4-tert-butylphenyl)amine and 1.2 g (13 mmol ) of sodium t-butoxide and 60 mg (0.15 mmol) of 2-dicyclohexane Silphosphino-2',6'-dimethoxy-1,1'-biphenyl (abbreviation: SPhos) The mixture was placed in a 200 mL three-neck flask, and the atmosphere in the flask was replaced with nitrogen. Xylene was added, and the mixture was degassed under reduced pressure. Then, 40 mg (70 μmol) of bicarbonate was added to the mixture. (dibenzylideneacetone)palladium(0) was added and the mixture was heated under a nitrogen atmosphere for 17 minutes. The mixture was stirred at 0°C for 4 hours.

[0444] After stirring, 400 mL of toluene was added to the resulting mixture, and then Florisil (Wako Pure Chemical Industries, Ltd.) was added. Co., Ltd., Catalog No.: 066-05265), Celite (Wako Pure Chemical Industries, Ltd., Catalog number: 537-02305), and suction-filtered through aluminum oxide to obtain the filtrate. The obtained filtrate was concentrated to give a brown solid.

[0445] This solid was purified by silica gel column chromatography (developing solvent: hexane:toluene=9: The target yellow solid was obtained by purifying it with toluene and hexane. The target yellow solid was obtained by recrystallization from hexane and ethanol in an amount of 1.5 g in a yield of 61%. The synthesis scheme is shown in (A-1) below.

[0446] [ka]

[0447] The resulting yellow solid (1.5 g) was purified by train sublimation. The yellow solid was heated at 315°C for 15 hours under a pressure of 4.5 Pa. Thereafter, 1.3 g of the target yellow solid was obtained with a recovery rate of 89%.

[0448] In addition, the yellow solid obtained in this synthesis 1The results of the H NMR measurements are shown below. 1 The H NMR charts are shown in Figures 15 and 16. Note that Figure 15(B) is the same as Figure 15(A). 15(a) to 15(c) are enlarged views of the range from 6.5 ppm to 9.0 ppm. A) is an enlarged view of the range from 0.5 ppm to 2.0 ppm. It was found that the product 2tBu-ptBuDPhA2Anth was obtained.

[0449] 1 H NMR (CDCl3,300MHz):σ=8.20-8.13(m, 2H), 8 .12(d, J=8.8Hz, 1H), 8.05(d, J=2.0Hz, 1H), 7.4 2(dd, J=9.3Hz, 2.0Hz, 1H), 7.32-7.26(m, 2H)7. 20(d, J=8.8Hz, 8H), 7.04(dd, J=8.8Hz, 2.4Hz, 8 H), 1.26(s, 36H), 1.18(s, 9H).

[0450] Next, the absorption and emission spectra of 2tBu-ptBuDPhA2Anth in toluene were The results of measuring the optical spectrum are shown in Figure 17. The absorption spectrum of the toluene solution was measured using Using an ultraviolet-visible spectrophotometer (V550 model, manufactured by JASCO Corporation), toluene alone was measured in a quartz The spectrum measured by inserting the sample into a filter was subtracted.

[0451] As shown in Figure 17, the toluene solution of 2tBu-ptBuDPhA2Anth exhibits a peak intensity of 468 nm and 37 Absorption peaks are observed at around 8 nm and 359 nm, and the emission wavelength peak is 523 nm (excitation wavelength The length was 440 nm. [Example]

[0452] In this example, an organic compound represented by structural formula (102) in Embodiment 1, which is one embodiment of the present invention, Compound, 2-tert-butyl-N,N,N',N'-tetrakis(3,5-di-tert -butylphenyl)-9,10-anthracenediamine (abbreviation: 2tBu-mmtBuD The synthesis method of PhA2Anth is described below. This compound is a light-emitting element according to one embodiment of the present invention. It is a guest material having a protecting group that can be suitably used for the compound.

[0453] <Step 1: Synthesis of bis(3,5-tert-butylphenyl)amine> 5.4 g (20 mmol) of 1-bromo-3,5-di-tert-butylbenzene and 5 0.0 g (24 mmol) of 3,5-di-tert-butylaniline and 4.7 g (49 mmol) ol) sodium t-butoxide was placed in a 200 mL three-neck flask and the flask was filled with nitrogen. To this mixture was added 100 mL of toluene, and the resulting mixture was degassed under reduced pressure. To this mixture, 1.3 mL (1.5 mmol) of tri-tert-butylphosphine (1 0 wt% hexane solution) and 0.17 g (0.3 mmol) of bis(dibenzylideneacetone) ) Palladium(0) was added, and the mixture was stirred at 120°C for 6 hours under a nitrogen stream.

[0454] After stirring, 300 mL of toluene was added to the resulting mixture, followed by Florisil, Celite, The filtrate was filtered through aluminum oxide under suction, and the filtrate was concentrated to give a brown solid. Got it.

[0455] This solid was purified by silica gel column chromatography (eluent: hexane:toluene=4: The product was purified by the method described in step 1) to give 7.5 g of a white solid in 95% yield. The synthesis scheme of 1 is shown in (B-1) below.

[0456] [ka]

[0457] <Step 2: Synthesis of 2tBu-mmtBuDPhA2Anth> 0.95 g (2.5 mmol) of 2-tert-butylanthracene and 2.0 g (5. 1 mmol) of bis(3,5-tert-butylphenyl)amine and 1.0 g (10 m mol) sodium t-butoxide and 60 mg (0.15 mmol) of SPhos The mixture was placed in a 200 mL three-neck flask, and the atmosphere in the flask was replaced with nitrogen. Xylene was added, and the mixture was degassed under reduced pressure. Then, 40 mg (70 μmol) of bicarbonate was added to the mixture. (dibenzylideneacetone)palladium(0) was added and the mixture was heated under a nitrogen atmosphere for 17 minutes. The mixture was stirred at 0°C for 5 hours.

[0458] After stirring, 400 mL of toluene was added to the resulting mixture, followed by Florisil, Celite, The filtrate was filtered through aluminum oxide under suction, and the filtrate was concentrated to give a brown solid. Got it.

[0459] This solid was purified by silica gel column chromatography (eluent: hexane:toluene=9: The yellow solid was purified by hexane and methanol. Recrystallization from ethanol gave 0.30 g of the target yellow solid in a yield of 12%. The synthesis scheme of Step 2 is shown below in (B-2).

[0460] [ka]

[0461] 0.30 g of the resulting yellow solid was purified by train sublimation. The purification was carried out by heating the yellow solid at 230°C for 15 hours under a pressure of 3.6 Pa. After the purification, the target yellow solid was obtained in a yield of 0.15 g and a recovery rate of 50%.

[0462] In addition, the yellow solid obtained in Step 2 above 1 The results of the H NMR measurements are shown below. Also, 1 The H NMR charts are shown in Figures 18 and 19. Note that Figure 18(B) is the same as Figure 18 This is a chart showing an enlarged range of 6.5 ppm to 9.0 ppm in (A). FIG. 19 is an enlarged view of the range from 0.5 ppm to 2.0 ppm in FIG. 18(A). From this result, 2tBu-mmtBuDPhA2Anth is obtained. It was found that

[0463] 1 H NMR (CD2Cl2, 300MHz):σ=8.25-8.20(m, 1H), 8.16-8.09(m, 1H), 8.03(d, J=1.5Hz, 1H), 7.48( dd, J=9.3Hz, 2.0Hz, 1H), 7.37-7.31(m, 2H), 6.9 7-6.95(m, 12H), 1.17(s, 9H), 1.15-1.13(m, 72H) ).

[0464] Next, the absorption spectrum of toluene solution of 2tBu-mmtBuDPhA2Anth and The results of measuring the emission spectrum are shown in Figure 20. The measurement method was the same as that shown in Example 1. be.

[0465] As shown in Figure 20, the toluene solution of 2tBu-mmtBuDPhA2Anth exhibits a peak at 466 nm and 3 Absorption peaks are observed around 79 nm and 358 nm, and the emission wavelength peak is 519 nm (excitation The wavelength was 458 nm. [Example]

[0466] In this example, the organic compound represented by the structural formula (101) of Embodiment 1, 2,6-di-t ert-butyl-N,N,N',N'-tetrakis(4-tert-butylphenyl)- 9,10-anthracene diamine (abbreviation: 2,6tBu-ptBuDPhA2Anth) This compound can be suitably used in a light-emitting element of one embodiment of the present invention. The guest material has a protecting group.

[0467] 1.6 g (3.6 mmol) of 2,6-di-tert-butylanthracene and 3.5 g (13 mmol) of bis(4-tert-butylphenyl)amine and 3.6 g (37 m mol) sodium t-butoxide and 0.18 g (1.1 mmol) of SPhos The mixture was placed in a 200 mL three-neck flask, and the atmosphere in the flask was replaced with nitrogen. Xylene was added, the mixture was degassed under reduced pressure, and 0.12 g (0.21 mmol) ) bis(dibenzylideneacetone)palladium(0) was added, and the mixture was heated under a nitrogen atmosphere. The mixture was stirred at 170°C for 22 hours.

[0468] After stirring, 400 mL of toluene was added to the resulting mixture, followed by Florisil, Celite, The filtrate was filtered through aluminum oxide under suction, and the filtrate was concentrated to give a brown solid. Got it.

[0469] This solid was purified by silica gel column chromatography (eluent: hexane:toluene=9: The target yellow solid was obtained by purifying the product using toluene. After recrystallization, 1.2 g of the desired yellow solid was obtained in 38% yield. The scheme is shown in (C-1) below.

[0470] [ka]

[0471] The resulting yellow solid (1.2 g) was purified by train sublimation. The yellow solid was heated at 315°C for 15 hours under a pressure of 4.0 Pa. After that, 0.94 g of the target yellow solid was obtained with a recovery rate of 82%.

[0472] In addition, the yellow solid obtained in Step 1 above 1 The results of the H NMR measurements are shown below. Also, 1 The H NMR charts are shown in Figures 21 and 22. Note that Figure 21(B) is the same as Figure 21 This is a chart showing an enlarged range of 6.5 ppm to 9.0 ppm in (A). FIG. 22 is an enlarged view of the range from 0.5 ppm to 2.0 ppm in FIG. 21(A). From this result, 2,6tBu-ptBuDPhA2Anth was obtained. It was found that

[0473] 1 H NMR(CDCl3,300MHz):σ=8.10(d, J=9.3Hz,2H ), 8.01(d, J=1.5Hz, 2H), 7.39(dd, J=9.3Hz, 2.0 Hz, 2H), 7.19-7.16(m, 8H)7.05-7.01(m, 8H), 1. 27(s, 36H), 1.17(s, 18H).

[0474] Next, the absorption spectrum of 2,6tBu-ptBuDPhA2Anth in toluene and The results of measuring the emission spectrum are shown in Figure 23. The measurement method was the same as that shown in Example 1. is.

[0475] From Figure 23, the toluene solution of 2,6tBu-ptBuDPhA2Anth has a wavelength of 462 nm, Absorption peaks are observed around 381 nm and 358 nm, and the emission wavelength peak is 523 nm (excitation The excitation wavelength was 455 nm. [Example]

[0476] In this example, an organic compound represented by structural formula (103) in Embodiment 1, which is one embodiment of the present invention, was used. compound, 2,6-di-tert-butyl-N,N,N',N'-tetrakis(3,5-di- tert-butylphenyl)-9,10-anthracenediamine (abbreviation: 2,6tBu- The synthesis method of mmtBuDPhA2Anth will be described. The guest material has a protecting group and can be suitably used in the light-emitting element of the embodiment.

[0477] 1.1 g (2.5 mmol) of 2,6-di-tert-butylanthracene and 2.3 g (5.8 mmol) of bis(3,5-tert-butylphenyl)amine and 1.1 g ( 11 mmol) sodium t-butoxide and 60 mg (0.15 mmol) SP The mixture was placed in a 200 mL three-neck flask and the atmosphere in the flask was replaced with nitrogen. 1 mL of xylene was added, and the mixture was degassed under reduced pressure. ) bis(dibenzylideneacetone)palladium(0) was added, and the mixture was heated under a nitrogen atmosphere. The mixture was stirred at 150°C for 6 hours.

[0478] After stirring, 400 mL of toluene was added to the resulting mixture, followed by Florisil, Celite, The filtrate was filtered through aluminum oxide under suction, and the filtrate was concentrated to give a brown solid. Got it.

[0479] This solid was purified by silica gel column chromatography (eluent: hexane:toluene=9: The yellow solid was purified by hexane and methanol. The target product was obtained as a yellow solid in an amount of 0.45 g in a yield of 17%. The synthesis scheme of Step 1 is shown below (D-1).

[0480] [ka]

[0481] The resulting yellow solid (0.45 g) was purified by train sublimation. The purification was carried out by heating the yellow solid at 275°C for 15 hours under a pressure of 5.0 Pa. After the purification, the target yellow solid was obtained in an amount of 0.37 g with a recovery rate of 82%.

[0482] In addition, the yellow solid obtained in Step 1 above 1 The results of the H NMR measurements are shown below. Also, 1 The H NMR charts are shown in Figures 24 and 25. Note that Figure 24(B) is the same as Figure 24 This is a chart showing an enlarged range of 6.5 ppm to 9.0 ppm in (A). FIG. 25 is an enlarged view of the range from 0.5 ppm to 2.0 ppm in FIG. 24(A). This is a chart showing the results. It was found that it was obtained.

[0483] 1H NMR (CDCl3,300MHz):σ=8.11(d, J=9.3Hz, 2H ), 7.92(d, J=1.5Hz, 1H), 7.34(dd, J=9.3Hz, 2.0 Hz, 2H), 6.96-6.95(m, 8H), 6.91-6.90(m, 4H), 1 .13-1.12(m, 90H).

[0484] Next, the absorption spectrum of 2,6tBu-mmtBuDPhA2Anth in toluene and The results of measuring the emission spectrum are shown in Figure 26. The measurement method was the same as that shown in Example 1. It seems that

[0485] From Figure 26, the toluene solution of 2,6tBu-mmtBuDPhA2Anth has a wavelength of 461 nm. Absorption peaks are observed around 379 nm and 358 nm, and the emission wavelength peak is 521 nm ( The excitation wavelength was 455 nm. [Example]

[0486] In this example, the organic compound of one embodiment of the present invention shown in Embodiment 1 as structural formula (104) was The compound 1,3,8,10-tetra-tert-butyl-7,14-bis(3,5-di- tert-Butylphenyl)-5,12-dihydroquino[2,3-b]acridine-7, This article explains how to synthesize 14-dione (abbreviation: Oct-tBuDPQd). is a guest material having a protecting group that can be suitably used in the light-emitting element of one embodiment of the present invention. is.

[0487] Step 1: 1,4-cyclohexadiene-1,4-dicarboxylic acid, 2,5-bis{( Synthesis of 3,5-di-tert-butylphenyl)amino}-dimethyl ester 5.6 g (24 mmol) of 1,4-cyclohexanedione-2,5-dicarboxylic acid dimethyl Add 10 g (48 mmol) of 3,5-di-tert-butylaniline to the chiller and The mixture was placed in a 200 mL three-neck flask equipped with a condenser and stirred at 170°C for 2 hours. Methanol was added to the resulting reddish-orange solid to form a slurry, and the mixture was collected by suction filtration. The solid was washed with hexane and methanol and dried, and the target reddish-orange solid was isolated. The synthesis scheme of Step 1 is shown below in (E-1).

[0488] [ka]

[0489] The obtained solid 1 The numerical data of H NMR are shown below. This indicates that the target compound was obtained. It was found that

[0490] 1 H NMR (chloroform-d, 500 MHz): δ = 10.6 (s, 2H), 7.2 0(t, J=1.5Hz, 2H), 6.94(d, J=2.0Hz, 4H), 3.65( s, 6H), 3.48(s, 4H), 1.33(s, 36H).

[0491] Step 2: 1,4-Benzenedicarboxylic acid, 2,5-bis{(3,5-di-tert Synthesis of (-butylphenyl)amino}-dimethyl ester 12 g (20 mmol) of 1,4-cyclohexadiene-1,4- obtained in Step 1 Dicarboxylic acid, 2,5-bis{(3,5-di-tert-butylphenyl)amino}-di The methyl ester and 150 mL of toluene were placed in a 300 mL three-neck flask equipped with a reflux condenser. The mixture was refluxed for 15 hours while bubbling air through it. After stirring, a precipitate was formed. The solid was collected by suction filtration and washed with hexane and methanol. The resulting filtrate was concentrated to obtain 7.3 g of a red solid, which was the target product. The product was washed with hexane and methanol and collected by suction filtration, revealing the target red solid. 3.1 g of the target compound was obtained. Thus, a total of 10.4 g of the target compound was obtained with a yield of 85%. The synthesis scheme of is shown below in (E-2).

[0492] [ka]

[0493] The obtained solid 1 The numerical data of H NMR are shown below. This indicates that the target compound was obtained. It was found that

[0494] 1 H NMR (chloroform-d, 500 MHz): δ = 8.84 (s, 2H), 8.1 8(s, 2H), 7.08(d, J=2.0Hz, 4H), 7.20(t, J=1.0H z, 2H), 3.83(s, 6H), 1.34(s, 36H).

[0495] Step 3: 1,4-Benzenedicarboxylic acid, 2,5-bis[N,N'-bis(3,5 Synthesis of (di-tert-butylphenyl)amino]-dimethyl ester 4.0 g (6.7 mmol) of 1,4-benzenedicarboxylic acid, 2 obtained in Step 2 ,5-bis{(3,5-di-tert-butylphenyl)amino}-dimethyl ester and , 3.9 g (14.6 mmol) of 1-bromo-3,5-di-tert-butylbenzene , 0.46 g (7.3 mmol) of copper, 50 mg of copper iodide (0.26 mmol) and 1.0 g (7.3 mmol) of potassium carbonate and 10 mL of xylene were added to a reflux condenser. The mixture was degassed under reduced pressure and then the atmosphere in the system was replaced with nitrogen. The mixture was refluxed for 20 hours, and 0.46 g (7.3 mmol) of copper was added to the resulting mixture. Then, 50 mg of copper iodide (0.26 mmol) was added and the mixture was refluxed for another 16 hours. Dichloromethane was added to the mixture to form a slurry. The solid was removed by suction filtration, and the obtained The filtrate was concentrated. The obtained solid was washed with hexane and ethanol. The compound was recrystallized from hexane / toluene to give 4.4 g of a yellow solid in 7% yield. The synthesis scheme for Step 3 is shown below (E-3).

[0496] [ka]

[0497] The obtained solid 1 The numerical data of H NMR are shown below. This indicates that the target compound was obtained. It was found that

[0498] 1 H NMR (chloroform-d, 500 MHz): δ = 7.48 (s, 2H), 6.9 7(t, J=2.0Hz, 4H), 7.08(d, J=1.5Hz, 8H), 3.25( s, 6H), 1.23(s, 72H).

[0499] Step 4: 1,3,8,10-tetra-tert-butyl-7,14-bis(3,5 -di-tert-butylphenyl)-5,12-dihydroquino[2,3-b]acridine Synthesis of 1,4-dione (abbreviation: Oct-tBuDPQd) 4.4 g (4.8 mmol) of 1,4-benzenedicarboxylic acid, 2 obtained in Step 3 ,5-Bis[N,N'-bis(3,5-di-tert-butylphenyl)amino]-dimethyl The ethyl ester and 20 mL of methanesulfonic acid were placed in a 100 mL three-neck flask equipped with a reflux condenser. The mixture was stirred at 160°C for 7 hours. The mixture was slowly poured into 300 mL of ice water and then allowed to cool to room temperature. The resulting solid was washed with water and a saturated aqueous solution of sodium bicarbonate. The resulting toluene solution was washed with water and saturated saline, dried over magnesium sulfate, and This mixture was then filtered through Celite (Wako Pure Chemical Industries, Ltd., catalog number: 537-02305). The filtrate was concentrated to give 3.3 g of black crystalline cellulose. A brown solid was obtained. The obtained solid was purified by silica gel column chromatography (developing solvent: hexane). The compound was purified by a solvent mixture (hexane:ethyl acetate=20:1) to give the desired compound as a red-orange solid in 15 minutes. The synthesis scheme of Step 4 is shown below in (E-4).

[0500] [ka]

[0501] In addition, the yellow solid obtained in step 4 above 1 The results of the H NMR measurements are shown below. Also, 1 The H NMR charts are shown in Figures 27 and 28. Note that Figure 27(B) is This is a chart showing an enlarged range of 6.5 ppm to 9.0 ppm in (A). FIG. 28 shows an enlarged view of the range from 0.5 ppm to 2.0 ppm in FIG. 27(A). This chart shows that Oct-tBuDPQd was obtained. Ta.

[0502] 1 H NMR (chloroform-d, 500 MHz): δ = 8.00 (s, 2H), 7.6 5(t, J=2.0Hz, 2H), 7.39(d, J=1.0Hz, 4H), 7.20( d, J=2.0Hz, 2H), 6.50(d, J=1.0Hz, 2H), 1.60(s, 18H), 1.39(s, 36H), 1.13(s, 18H).

[0503] Next, the absorption and emission spectra of the dichloromethane solution of Oct-tBuDPQd were measured. The results of measuring the torque are shown in Figure 29. The measurement method was the same as that shown in Example 1.

[0504] As shown in Figure 29, the dichloromethane solution of Oct-tBuDPQd exhibits the following wavelengths: 510 nm, 480 nm, An absorption peak is observed around 447 nm, and the emission wavelength peak is 591 nm (excitation wavelength 510 nm).

[0505] Next, the HOMO and LUMO levels of Oct-tBuDPQd were determined by cyclic boron transfer. The results are calculated based on voltammetry (CV) measurements. The calculation method is shown below.

[0506] The measurement device used was an electrochemical analyzer (manufactured by BAS Co., Ltd., model number: ALS model). The solution used in the CV measurements was dehydrated dimethyl ether. Dimethylformamide (DMF) (Aldrich Corporation, 99.8%, Catalog No. 227 05-6) was used, and the supporting electrolyte was tetra-n-butylammonium perchlorate (nB u4NClO4) (Tokyo Chemical Industry Co., Ltd., Catalog No.: T0836) at 100 mmol / The measurement target is dissolved in a solution to a concentration of 2 mmol / L. The working electrode was a platinum electrode (PT, manufactured by BAS Co., Ltd.). E platinum electrode), and as an auxiliary electrode, a platinum electrode (B.A.S. Co., Ltd., VC-3 P The counter electrode (5 cm) was used as the reference electrode, and Ag / Ag + Electrode (B.A.E. The measurements were carried out at room temperature (20°C). The scan rate during CV measurement was standardized to 0.1 V / sec. The oxidation potential Ea [V] and reduction potential Ec [V] relative to the reference electrode were measured. The potential of the α-reduction wave is defined as the midpoint potential of the α-reduction wave, and Ec is defined as the midpoint potential of the α-reduction wave. The potential energy of the reference electrode relative to the vacuum level is -4.94 eV. Therefore, the HOMO level [eV] = -4.94-Ea, the LUMO level [e V]=-4.94-Ec, calculate the HOMO and LUMO levels, respectively. It is possible.

[0507] The CV measurement was repeated 100 times, and the oxidation-reduction wave in the 100th cycle and the 1st cycle were measured. The electrical stability of the compounds was investigated by comparing the redox waves of the first compound.

[0508] As a result, the HOMO level of Oct-tBuDPQd is -5.60 eV and the LUMO level is - In addition, the repetitive measurement of the oxidation-reduction wave revealed that the When comparing the waveforms after the first and 100th cycle, the oxidation potential Ea [V] was 7. The peak intensity of Oct-tBuDPQd was maintained at 4%. This indicates that Oct-tBuDPQd is resistant to oxidation. was confirmed to be high.

[0509] In addition, thermogravimetry and differential thermal analysis (TTA) of Oct-tBuDPQd try-Differential Thermal Analysis:TG-DTA The measurements were carried out using a high vacuum differential thermobalance (manufactured by Bruker AXS Co., Ltd.). The measurement was carried out at 10 Pa with a temperature rise rate of 10°C / The measurements were carried out under nitrogen flow (flow rate 2.4 mL / min). In the analysis, the weight of Oct-tBuDPQd obtained by thermogravimetry was -5% of the weight at the start of the measurement. The temperature at which the decomposition occurs (decomposition temperature) is 234°C, which is a relatively low temperature at 10 Pa. It was shown that it sublimes at 100°C. [Example]

[0510] Example 1 In this example, examples of fabrication of a light-emitting element of one embodiment of the present invention and a comparative light-emitting element and characteristics of the light-emitting element will be described. The structure of the light-emitting element manufactured in this example is the same as that shown in FIG. The details of the structures are shown in Tables 1 to 3. The structures and abbreviations of the compounds used are shown below. For other organic compounds, the above examples and embodiments may be referred to.

[0511] [ka]

[0512] [Table 1]

[0513] [Table 2]

[0514] [Table 3]

[0515] <Fabrication of light-emitting devices> A method for manufacturing the light-emitting element manufactured in this example will be described below.

[0516] <Fabrication of Light-Emitting Elements 1 to 4> An ITSO film was formed on a glass substrate as an electrode 101 to a thickness of 70 nm. The electrode area of the electrode 101 is 4 mm 2 (2mm x 2mm).

[0517] Next, a hole injection layer 111 made of DBT3P-II and molybdenum oxide was formed on the electrode 101. (MoO3) and the weight ratio (DBT3P-II:MoO3) was 1:0.5. The co-deposition was carried out so that the thickness was 40 nm.

[0518] Next, a hole transport layer 112 was formed on the hole injection layer 111 by depositing PCCP to a thickness of 20 nm. The vapor deposition was carried out so that

[0519] Next, a light-emitting layer 130 containing 4,6mCzP2Pm and tris[ 2-(1H-pyrazol-1-yl-κN 2 )phenyl-κC]iridium(III)( Abbreviation: Ir(ppz)3) and 2tBu-ptBuDPhA2Anth in a weight ratio of (4 ,6mCzP2Pm:Ir(ppz)3:2tBu-ptBuDPhA2Anth) is 0 The layers were co-deposited in a ratio of 0.8:0.2:1 and to a thickness of 40 nm. In 130, Ir(ppz)3 is a phosphorescent material having Ir, and 4,6mCzP 2Pm and Ir(ppz)3 form an exciplex. uDPhA2Anth is a fluorescent material having a protecting group. The value of x1 is The value of x1 for each light-emitting element is shown in Table 3.

[0520] Next, on the light-emitting layer 130, 4,6mCzP2Pm was deposited to a thickness of 2 The layers were deposited in order so that the thickness of NBPhen was 10 nm. On the electron transport layer 118, LiF was deposited to a thickness of 1 nm as the electron injection layer 119. It was evaporated.

[0521] Next, on the electron injection layer 119, aluminum (Al) was deposited to a thickness of 20 It was formed so that the thickness was 0 nm.

[0522] Next, in a glove box with a nitrogen atmosphere, a glass substrate for sealing is attached to an organic The EL sealant is used to fix the organic material to the glass substrate, forming a light-emitting element 1. The light-emitting element 4 was sealed. Specifically, a seal was formed around the organic material formed on the glass substrate. The glass substrate is then bonded to a sealing glass substrate, and the wavelength is 365nm. m of ultraviolet light at 6 J / cm 2 The light was irradiated and then heat-treated at 80°C for 1 hour. Light-emitting elements 1 to 4 were obtained.

[0523] <Fabrication of Light-Emitting Elements 5 to 16 and Comparative Light-Emitting Elements 17 to 29> Light-emitting elements 5 to 16 and comparative light-emitting elements 17 to 29 are the light-emitting elements shown above. The only difference between the optical elements 1 to 4 is the fluorescent material (guest material) used in the light-emitting layer 130. The other steps were the same as those for fabricating the light-emitting element 1. Details of the element structure are shown in Tables 1 to 3. The details of the fabrication method are omitted here.

[0524] The guest materials used in the light-emitting elements 1 to 16 have protecting groups around the luminophores. The guest materials used in comparative light-emitting elements 17 to 28 do not have bulky substituents. Furthermore, the comparative light-emitting element 29 does not use a guest material in the light-emitting layer. The emission observed from molecule 29 is due to the excitation formed by 4,6mCzP2Pm and Ir(ppz)3. This is the luminescence of the cation complex.

[0525] <Light-emitting element characteristics> Next, the fabricated light-emitting elements 1 to 16 and comparative light-emitting elements 17 to 19 were The characteristics of the 29-color element were measured. The luminance and CIE chromaticity were measured using a color luminance meter (manufactured by Topcon Corporation). BM-5A) was used, and a multichannel spectrometer (Hamamatsu Photonics) was used to measure the electroluminescence spectrum. A meter (PMA-11, manufactured by Nix Co., Ltd.) was used.

[0526] External quantum efficiency of light-emitting element 1 to light-emitting element 16 and comparative light-emitting element 17 to comparative light-emitting element 29 The efficiency-luminance characteristics of the light-emitting elements 1 to 16 are shown in FIGS. and 2.5 mA / cm for each of the comparative light-emitting elements 17 to 29. 2 current density of The electroluminescence spectra when a current was passed through the electrodes are shown in Figs. The optical element was measured at room temperature (in an atmosphere maintained at 23°C).

[0527] Also, 1000 cd / m 2Light-emitting elements 1 to 16 and comparative light-emitting element Tables 4 and 5 show the device characteristics of the light-emitting elements 17 to 29.

[0528] [Table 4]

[0529] [Table 5]

[0530] As shown in FIG. 37, the emission spectra of the light-emitting elements 1 to 4 have peak wavelengths of 5 35nm and the half-width is about 67nm. As shown in FIG. 38, light-emitting elements 5 to 10 emit green light. The emission spectrum of molecule 8 has a peak wavelength of approximately 522 nm and a half-width of approximately 68 nm. The green luminescence was derived from 2tBu-mmtBuDPhA2Anth. As shown in FIG. 39, the emission spectra of the light-emitting elements 9 to 12 have a peak wavelength of 5 2,6tBu-ptBuDPhA2, with a wavelength of approximately 30 nm and a half-width of approximately 65 nm. Furthermore, as shown in FIG. 40, the light-emitting elements 13 to 15 exhibited green light emission originating from Anth. The emission spectrum of the light emitting element 16 has a peak wavelength of about 521 nm and a half width of 67 nm. The green luminescence is due to 2,6tBu-mmtBuDPhA2Anth, which has a molecular weight of approximately 10 ... As shown in FIG. 41, the emission spectra of the comparative light-emitting elements 17 to 20 were The peak wavelength is about 540 nm and the half-width is about 66 nm. As shown in FIG. 42, the comparative light-emitting elements 21 to 23 emit green light. The emission spectrum of the optical element 24 has a peak wavelength of about 530 nm and a half width of 65 nm. The green luminescence derived from MeDPhA2A was observed before and after the reaction. The emission spectra of the comparative light-emitting elements 25 to 28 have a peak wavelength of 523nm. The green emission from mMeDPhA2A is approximately m and the half-width is approximately 68 nm. Therefore, the light-emitting elements 1 to 16 and the comparative light-emitting elements 17 to 19 are shown. It was found that 28 emits light originating from the fluorescent material contained in each element. 37, the emission spectrum of the comparative light-emitting element 29 has a peak wavelength of 53 1 nm and the half-width was about 88 nm. ppz)3, the emission spectra obtained from the comparative light-emitting element 29 are different. The emission observed is that of the exciplex formed by 4,6mCzP2Pm and Ir(ppz)3. I discovered something.

[0531] The emission spectra of the guest materials contained in each material in solution (e.g., toluene solution) The shape of the PL spectrum and the emission spectrum in the light-emitting device (EL spectrum) is slightly different. This is because the emission of the guest material may differ depending on the recombination region or the recombination region. This is because the light is affected by the optical path length from the coupling region to the outside. Furthermore, even in light-emitting devices using the same guest material, the shapes of the emission spectra do not completely match. In this case, the influence of the recombination region and the optical path length differs slightly for each light-emitting element. This is the case.

[0532] The light-emitting elements 1 to 16 and the comparative light-emitting elements 17 to 28 are made of a fluorescent material. Although the light emission is derived from the The device exhibited high luminous efficiency, with an external quantum efficiency exceeding 9%. The light-emitting elements 1 to 16 are the light-emitting elements of Comparative Light-Emitting Element 1 at any concentration. The external quantum efficiency of the light-emitting element No. 7 to the comparative light-emitting element No. 28 was higher than that of the light-emitting element No. 7 to the comparative light-emitting element No. 28. In the light-emitting device, non-radiative deactivation of triplet excitons is suppressed, and the singlet excitation energy and triplet It can be said that both excitation energies are efficiently converted into light emission from the fluorescent material.

[0533] 37 to 40, the energy donors 4,6mCzP2Pm and Ir(p pz)3 and light emission from the light-emitting element of each embodiment of the present invention, In other words, the light emitted from each energy acceptor (guest material) has the same color. Therefore, in the light-emitting element of one embodiment of the present invention, Although a guest material with a different emission color is used, a highly efficient light-emitting device has been obtained. As mentioned above, when the emission colors of the energy donor and the energy acceptor are close, the formula ( 1) Although the rate constant of energy transfer by the Förster mechanism is decreased, In the light-emitting element of this embodiment, the concentration of the fluorescent material that is the energy donor can be increased. Therefore, a fluorescent material with an emission color close to that of the energy donor is used as the guest material. You can be there.

[0534] As mentioned above, the emission spectrum of the toluene solution of 2tBu-mmtBuDPhA2Anth The peak wavelength of the tor is 519 nm, and the excitation of 4,6mCzP2Pm and Ir(ppz)3 The peak wavelength of the emission spectrum exhibited by the complex was 531 nm. Thus, in the light-emitting device of one embodiment of the present invention, a combination in which the emission colors of the energy donor and the energy acceptor are close to each other can also be preferably used.

[0535] The generation probability of singlet excitons generated by the recombination of carriers (holes and electrons) injected from a pair of electrodes is at most 25%. Therefore, when the external light extraction efficiency is 30%, the external quantum efficiency of the fluorescent light-emitting device is at most 7.5%. However, in light-emitting devices 1 to 16 and comparative light-emitting devices 17 to 28, an efficiency higher than 7.5 % has been obtained. This is because, in addition to the light emission derived from singlet excitons generated by the recombination of carriers (holes and electrons) injected from a pair of electrodes, light emission derived from energy transfer from triplet excitons or light emission derived from singlet excitons generated from triplet excitons by reverse intersystem crossing in an exciplex is obtained from the fluorescent material. That is, light-emitting devices 1 to 16 and comparative light-emitting devices 17 to 28 can be regarded as light-emitting devices using ExEF.

[0536] <CV measurement results> Next, the electrochemical properties (oxidation reaction properties and reduction reaction properties) of 4,6mCzP2Pm and Ir(ppz)3 used in the light-emitting layer of each light-emitting device were measured by cyclic voltammetry (CV ). The measurement method was the same as the method described in Example 5.

[0537] As a result of the CV measurement, the oxidation potential of 4,6mCzP2Pm was 0.95 V and the reduction potential was -2.0 6 V. Also, the HOMO level of 4,6mCzP2Pm calculated from the CV measurement was -5 The LUMO level was -2.88 eV and the oxidation potential of Ir(ppz)3 was -0.89 eV. The potential was 0.45 V and the reduction potential was -3.17 V. The Ir( The HOMO level of ppz)3 was −5.39 eV and the LUMO level was −1.77 eV.

[0538] As mentioned above, the LUMO level of 4,6mCzP2Pm is the same as that of Ir(ppz)3. The HOMO level of Ir(ppz)3 is lower than the HOMO level of 4,6mCzP2Pm. Therefore, when this compound is used in the light-emitting layer, electrons and holes are efficiently transported in the 4 ,6mCzP2Pm and Ir(ppz)3, respectively, and 4,6mCzP2Pm and I It can form an exciplex with r(ppz)3.

[0539] 37 and the emission spectrum of the comparative light-emitting element 29 shown in FIGS. 17, 20, 23 and 24. The absorption spectra of the guest materials used as the guest materials in the light-emitting elements 1 to 16 shown in FIG. When comparing the spectra, the absorption band at the longest wavelength side of the absorption spectrum and the emission spectrum Therefore, the light-emitting elements 1 to 16 have the above-described exciplexes. It can be seen that the light is emitted by receiving excitation energy. The EL (emission) spectrum of Light-emitting element 9 and the torsion of each guest material used in Light-emitting element 1 to Light-emitting element 12 are shown in FIG. The relationship between the absorption spectrum and the emission spectrum in the ene solution is shown in Figure 161. When comparing the absorption spectra of the materials, the absorption band at the longest wavelength side of the absorption spectrum and the emission It can be seen that the spectra have overlap.

[0540] <Changes in external quantum efficiency due to guest material concentration> Figure 44 shows the relationship between the guest material concentration and the external quantum efficiency for each guest material. Light-emitting Elements 1 to 16 of One Embodiment of the Present Invention Using Guest Materials Having More Protective Groups In the comparative light-emitting element, the decrease in efficiency with increasing concentration is suppressed compared to the comparative light-emitting element 17 to the comparative light-emitting element 28. As described above, the comparative light-emitting elements 17 to 28 were used The fluorescent material used as the guest material has the function of converting triplet excitation energy into light emission. In a fluorescent light-emitting device using a material that emits light as a host material, increasing the concentration of the guest material There was a problem in that the light efficiency was significantly reduced. When the guest material concentration was changed from 1 wt% to 10 wt%, the external quantum efficiency increased from 40% to That is, the comparative light-emitting elements 17 to 28 have a decrease in the luminance of about 50%. It has been shown that the energy transfer by the star mechanism cannot be suppressed. In a light-emitting element using a fluorescent material having a protecting group as a guest material, which is one embodiment of the present invention, In addition, depending on the guest material, increasing the concentration can improve the luminescence efficiency. It was also shown that the efficiency was improved by using a guest material with a protecting group in the light-emitting layer. The triplet excitation energy is transferred from the host material to the guest material by the Dexter mechanism. This is because the energy transfer and the quenching of triplet excitation energy are suppressed. By increasing the concentration of the material, the host material is transferred to the guest material via the Förster mechanism. The energy transfer of excitation energy can be efficiently utilized, and the triplet excitation energy can be This is because both the excited states and the doublet energy can be efficiently converted into light emission from the fluorescent material. In particular, a diphenylamino group is attached to the luminophore, and the phenyl group has two protecting groups, The two protecting groups are attached to the 3- and 5-positions of the phenyl group, 2tBu-mmtBuD PhA2Anth and 2,6tBu-mmtBuDPhA2Anth were used as guest materials. In addition, it was found that the effect was particularly large in the light-emitting elements 5 to 8 and the light-emitting elements 13 to 16. By having a protecting group at the bonding position, the luminophore is efficiently separated from the host material. From the above, it is suggested that the light-emitting element of one embodiment of the present invention can It was found that a light-emitting element having a high concentration of the starting material and high luminous efficiency could be obtained.

[0541] <Fluorescence lifetime measurement of light-emitting elements> Next, in order to investigate the difference in the emission rate depending on the concentration of each guest material, The fluorescence lifetime of the device was measured using a picosecond fluorescence lifetime measurement system (Hamamatsu Photonics). In this measurement, in order to measure the lifetime of the fluorescent light emitted from the light-emitting element, A rectangular pulse voltage is applied to the electrode, and the light emitted from the electrode decays from the falling edge of the voltage. The pulse voltage was applied at a frequency of 10 Hz, and the data were collected repeatedly. By integrating the data, data with a high S / N ratio was obtained. The luminance of the light-emitting element is 1000 cd / m 2 Apply pulse voltage of 3V to 4V The applied pulse duration was 100 μsec, and the negative bias voltage was -5 V (element drive ...

Claims

[Claim 1] A light-emitting element having a light-emitting layer between a pair of electrodes, the light-emitting layer includes a first material having a function of converting triplet excitation energy into luminescence, and a second material having a function of converting singlet excitation energy into luminescence; the second material comprises a lumophore and five or more protecting groups; the luminophore is a fused aromatic ring or a fused heteroaromatic ring; the five or more protecting groups each independently include one of an alkyl group having from 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having from 3 to 10 carbon atoms, or a trialkylsilyl group having from 3 to 12 carbon atoms; A light-emitting element in which light is emitted from the second material.

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