Light-emitting device, light-emitting apparatus, electronic device, and lighting device

Abstract

To provide a multicolor light-emitting device having high luminous efficiency.SOLUTION: A light-emitting device contains a material serving as an energy donor, a fluorescent material, and a phosphorescent material in a light-emitting layer. The material serving as an energy donor has a function of converting triplet excitation energy into light emission. A molecular structure of the fluorescent material includes a luminophore and protecting groups, and five or more protecting groups are contained in one molecule of a guest material. Introduction of protecting groups into molecules inhibits triplet excitation energy transfer from the material serving as an energy donor to the light-emitting material by a Dexter mechanism. Each of the protecting groups is an alkyl group or a branched-chain alkyl group. In the light-emitting device, light emission is obtained from both the fluorescent material and the phosphorescent material.SELECTED DRAWING: Figure 2

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 the like. and lighting devices.

[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 excitation 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) Delayed Fluorescence (TADF) materials are known. In F materials, a singlet excited state is generated from the triplet excited state by reverse intersystem crossing, and the singlet excited state It is converted from an excited state to luminescence.

[0009] In order to increase the luminous efficiency of light-emitting devices using TADF materials, In this case, not only is the singlet excited state efficiently generated from the triplet excited state, but the singlet excited state is also efficiently generated. It is important that the fluorescent substance can emit light efficiently from the fluorescent state, i.e., that the fluorescent quantum yield is high. However, it is difficult to design a light-emitting material that satisfies both of these requirements simultaneously.

[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.,Sci. Adv. 2018,4,eaao6910 [Non-patent document 2] S. Wang et al., Angew. Chem.,Int.Ed. 2015,54,13068. Summary of the Invention [Problem to be solved by the invention]

[0013] Multicolor light-emitting devices, such as white light-emitting devices, are expected to be used in displays and other applications. The element configuration for obtaining the multicolor light-emitting element is a structure in which a plurality of EL layers are arranged via a charge generating layer. The tandem element has different light-emitting diodes (also called tandem elements). Multicolor light-emitting devices can be fabricated by using different colored materials for each EL layer. However, since the tandem element has a large number of layers, there is a problem that the manufacturing process is many. There is a problem.

[0014] Therefore, there is a demand for a light-emitting device that can emit light of multiple colors from a single EL layer. To obtain a desired color, two or more guest materials are used in the light-emitting layer. There is a demand for the development of multicolor light-emitting devices using photo-sensitive materials.

[0015] As described above, in order to improve the efficiency of a light-emitting device using a fluorescent material, for example, After converting the doublet excitons into singlet excitons, the singlet excitation energy is transferred to the fluorescent guest material. However, in the light-emitting layer of the light-emitting element, When used as a guest material, the lowest triplet excited energy level (T 1 level) does not contribute to luminescence, but can be a deactivation pathway for triplet excitation energy. However, it has been difficult to improve the efficiency of light-emitting elements using fluorescent materials.

[0016] Therefore, in order to increase the luminous efficiency of light-emitting elements using fluorescent materials and also improve their reliability, The triplet excitation energy in the light-emitting layer can be efficiently converted into singlet excitation energy. The triplet excitation energy is then efficiently transferred to the fluorescent material as singlet excitation energy. Therefore, it is preferable to transfer energy from the triplet excited state of the host material to the guest material. The singlet excited state of the material is efficiently generated, and the light-emitting efficiency of the light-emitting device is further improved. Therefore, there is a need to develop methods that will also improve reliability.

[0017] Therefore, in one embodiment of the present invention, a light-emitting element that emits light of a plurality of colors from a single EL layer One embodiment of the present invention provides a light-emitting element with high emission efficiency. 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. Another object of one embodiment of the present invention is to provide a novel light-emitting device. Another object of one embodiment of the present invention is to provide a novel display device.

[0018] 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]

[0019] 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. At the same time, there is a demand for the development of a light-emitting device that can efficiently emit multicolor light.

[0020] 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 that converts triplet excitation energy into luminescence and a third material that converts triplet excitation energy into luminescence. a third material having a function of forming a luminophore, and the second material having a luminophore and five or more protecting groups; The luminophore is a fused aromatic ring or a fused heteroaromatic ring, and the five or more protecting groups are each independently alkyl groups having 1 to 10 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 10 carbon atoms; a trialkyl group having 3 to 12 carbon atoms, or a trialkylsilyl group having 3 to 12 carbon atoms, The lowest triplet excitation energy level (T1 level) of the material is lower than the T1 level of the third material. The light-emitting element is highly efficient and emits light from both the second material and the third material.

[0021] 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.

[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 triplet excitation energy into luminescence and a second material having a function of converting triplet excitation energy into luminescence. The second material has a luminophore and four protecting groups, and the third material has a function of emitting light. The group is a fused aromatic ring or a fused heteroaromatic ring, and the four protecting groups are fused aromatic rings or fused heteroaromatic rings. The four protecting groups are not directly bonded to the ring, and each of the four protecting groups is independently an alkyl group having 3 to 10 carbon atoms. group, substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, The T1 level of the first material is equal to that of the third material. The light-emitting device has a T1 level higher than that of the second material and a third material, and emits light from both the second material and the third material. do.

[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 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 amino group independently has at least one protecting group, and each protecting group independently has at least one protecting group. In particular, alkyl groups having 3 to 10 carbon atoms, substituted or unsubstituted alkyl groups having 3 to 10 carbon atoms and a trialkylsilyl group having 3 to 12 carbon atoms. The light-emitting element is a light-emitting element that emits light from both the first material and the second material.

[0024] 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 triplet excitation energy into luminescence and a second material having a function of converting triplet excitation energy into luminescence. and a third material having a function of forming a luminophore and two or more diarylamino groups. group, the luminophore is a fused aromatic ring or a fused heteroaromatic ring, The aromatic ring is bonded to two or more diarylamino groups, and the two or more diarylamino groups are each Each of the protecting groups independently has at least two protecting groups, and the protecting groups each independently have 3 to 1 carbon atoms. an alkyl group having 3 to 10 carbon atoms; a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms; The first material has a trialkylsilyl group having 3 to 12 carbon atoms, and the second material has a T1 level. The T1 level is higher than the T1 level of the third material, and light is emitted from both the second and third materials. It is a light-emitting element.

[0025] In the above structure, the diarylamino group is preferably a diphenylamino group.

[0026] In the above structure, the alkyl group is preferably a branched chain alkyl group.

[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 triplet excitation energy into luminescence and a second material having a function of converting triplet excitation energy into luminescence. the second material has a luminophore and a plurality of protecting groups, and The protecting group is a fused aromatic ring or a fused heteroaromatic ring, and at least one of the atoms constituting the protecting group is , which is located directly on one side of the fused aromatic ring or fused heteroaromatic ring and which comprises a plurality of protecting groups. At least one of the atoms forming the fused aromatic ring or fused heteroaromatic ring is located directly above the other face of the fused aromatic ring or heteroaromatic ring. The T1 level of the first material is higher than the T1 level of the third material, and the T1 levels of the second and third materials are It is a light-emitting element that emits light from both materials.

[0028] 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 triplet excitation energy into luminescence and a second material having a function of converting triplet excitation energy into luminescence. and a third material having a function of forming a luminophore and two or more diphenylamino groups. group, the luminophore is a fused aromatic ring or a fused heteroaromatic ring, The aromatic ring is bonded to two or more diphenylamino groups, and the phenyl groups in the two or more diphenylamino groups The aryl groups each independently have protecting groups at the 3- and 5-positions, and the protecting groups each independently are alkyl groups having 3 to 10 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 10 carbon atoms; a trialkyl group having 3 to 12 carbon atoms, or a trialkylsilyl group having 3 to 12 carbon atoms; The T1 level of the material is higher than the T1 level of the third material, and the T1 level of the second material is higher than the T1 level of the third material. It is a light-emitting element that can emit light.

[0029] In the above structure, the alkyl group is preferably a branched chain alkyl group.

[0030] In the above structure, the branched chain alkyl group preferably has a quaternary carbon.

[0031] 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.

[0032] 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.

[0033] In the above-described configuration, the peak wavelength of the emission spectrum of the first material is equal to or greater than the peak wavelength of the emission spectrum of the second material. It is preferable that the wavelength is located on the shorter wavelength side than the peak wavelength of the optical spectrum.

[0034] In the above structure, the first material is preferably a compound that exhibits phosphorescence or delayed fluorescence. I wish.

[0035] In the above configuration, the emission spectrum of the first material is equal to the absorption spectrum of the second material. It is preferable that the absorption band overlaps with the absorption band on the longest wavelength side of the above.

[0036] In the above structure, the concentration of the second material in the light-emitting layer is higher than the concentration of the third material. This is preferable.

[0037] In the above structure, the third material is preferably a compound that exhibits phosphorescence.

[0038] In the above-described configuration, the peak wavelength of the emission spectrum of the second material is It is preferable that the wavelength is located on the shorter wavelength side than the peak wavelength of the emission spectrum.

[0039] 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). Optical element connector, 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 be included in the light emitting device. [Effects of the Invention]

[0040] According to one embodiment of the present invention, a light-emitting element capable of emitting a plurality of light colors from a single EL layer is provided. According to one embodiment of the present invention, a light-emitting element with high emission efficiency can be provided. According to one embodiment of the present invention, a light-emitting element with reduced power consumption can be provided. According to one embodiment of the present invention, a novel light-emitting element can be provided. According to one embodiment of the present invention, a novel light-emitting device can be provided. This makes it possible to provide a novel display device.

[0041] 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]

[0042] [Figure 1] 1A and 1B are schematic cross-sectional views of a light-emitting layer of a light-emitting element according to one embodiment of the present invention, and FIG. 1C is a diagram illustrating the correlation between energy levels of a light-emitting layer of a light-emitting device according to one embodiment of the present invention. [Figure 2] 1A and 1B are conceptual diagrams of a conventional guest material and a guest material used in a light-emitting element according to one embodiment of the present invention, respectively. [Figure 3] (A) A structural formula of a guest material used in a light-emitting element of one embodiment of the present invention. (B) A ball-and-stick diagram of a guest material used in a light-emitting element of one embodiment of the present invention. [Figure 4] 1A is a schematic cross-sectional view of a light-emitting layer of a light-emitting element according to one embodiment of the present invention, and FIGS. 1B to 1D are diagrams illustrating the correlation between energy levels of a light-emitting layer of a light-emitting device according to one embodiment of the present invention. [Figure 5] 1A is a schematic cross-sectional view of a light-emitting layer of a light-emitting element according to one embodiment of the present invention, and FIGS. 1B and 1C are diagrams illustrating the correlation between energy levels of a light-emitting layer of a light-emitting device according to one embodiment of the present invention. [Figure 6] 1A and 1B are schematic cross-sectional views of a light-emitting element according to one embodiment of the present invention. [Figure 7] 1A and 1B are a top view and a cross-sectional view, respectively, illustrating a display device according to one embodiment of the present invention; [Figure 8] 1A and 1B are schematic cross-sectional views illustrating a display device according to 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 to 1D are perspective views illustrating a display module of one embodiment of the present invention. [Figure 11] 1A to 1C illustrate electronic devices of one embodiment of the present invention. [Figure 12] 1A and 1B are perspective views illustrating a display device according to one embodiment of the present invention. [Figure 13] 1A to 1C illustrate a lighting device according to one embodiment of the present invention. [Figure 14] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 15] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 16] 10A and 10B are diagrams illustrating the relationship between the electroluminescence spectrum of a light-emitting element, and the absorption spectrum and emission spectrum of a compound according to an example. [Figure 17] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 18] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 19] FIG. 10 is a graph illustrating the chromaticity-luminance characteristics of a light-emitting element according to an embodiment. [Figure 20] 10A to 10C are diagrams illustrating the results of a reliability test on a light-emitting element according to an example. [Figure 21] 10A and 10B are graphs illustrating electroluminescence spectra of a light-emitting element before and after a reliability test according to an example. [Figure 22] (A)(B) NMR charts of compounds according to reference examples. [Figure 23] FIG. 1 is a diagram illustrating an NMR chart of a compound according to a reference example. [Figure 24] (A) (B) NMR charts of compounds according to reference examples. [Figure 25] FIG. 1 is a diagram illustrating an NMR chart of a compound according to a reference example. [Figure 26] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 27] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 28] FIG. 10 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an example. [Figure 29] 10A and 10B are graphs illustrating electroluminescence spectra of light-emitting elements according to Examples. [Figure 30] (A)(B) NMR charts of compounds according to reference examples. [Figure 31] FIG. 1 is a diagram illustrating an NMR chart of a compound according to a reference example. DETAILED DESCRIPTION OF THE INVENTION

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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

[0048] 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 singlet excited energy 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.

[0049] 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.

[0050] 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.

[0051] 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. In addition, the two emission spectra have peaks in the same wavelength region. Even if the two types of light have different peaks, if the peak wavelengths are different, the two types of light emission spectra will be different. The emission spectrum peak may be a maximum or a short This includes the ruler.

[0052] (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.

[0053] <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.

[0054] FIG. 1A is a schematic cross-sectional view of a light-emitting element 150 of one embodiment of the present invention.

[0055] 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. .

[0056] 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.

[0057] In this embodiment, of the pair of electrodes, electrode 101 is an 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. .

[0058] 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

[0059] <Light-emitting mechanism of light-emitting elements> Next, the light emitting mechanism of the light emitting layer 130 will be described below.

[0060] 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, a material that can convert triplet excitation energy into luminescence is used. This is preferable.

[0061] Phosphorescence is a material that has the function of converting triplet excitation energy into luminescence. Examples of such compounds include compounds that can emit light (hereinafter also referred to as phosphorescent materials). In this context, phosphorescent materials are materials that emit light in a temperature range above low temperature (e.g., 77 K) and below room temperature (i.e., A compound that exhibits phosphorescence but does not exhibit fluorescence at any temperature (temperatures above 313K or below 313K). The phosphorescent material preferably contains a metal element with a large spin-orbit interaction. Specifically, transition metal elements are preferred, and platinum group elements (ruthenium (Ru), rhodium (Ru), etc.) are particularly preferred. Rh, Pd, Os, Ir, or It is preferable to have platinum (Pt), and in particular, by having iridium, it is possible to This is preferable because it can increase the transition probability involved in the direct transition between the excited state and the triplet excited state.

[0062] 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 mechanism for converting energy from triplet excited energy to singlet excited energy by crossover 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

[0063] As an index of the T1 level, the phosphorescence spectrum observed at low temperatures (e.g., 10 K) is used. For TADF materials, it is sufficient to draw a tangent at the short wavelength side of the fluorescence spectrum. The energy of the wavelength of the extrapolated line is taken as the S1 level, and the short wavelength side of the phosphorescence spectrum is When a tangent line is drawn and the energy of the wavelength of the extrapolated line is the T1 level, the relationship between S1 and T1 is The difference is preferably 0.2 eV or less.

[0064] 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.

[0065] 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, light-emitting layer 130 comprises Compound 131, Compound 132, and Compound 136. Compound 131 has the function of converting triplet excitation energy into luminescence, and compound 132 has the function of converting singlet excitation energy into luminescence, and compound 136 has the function of converting triplet excitation energy into luminescence. The fluorescent material has a high stability, so it can emit light with high reliability. To obtain a device, it is preferable to use a fluorescent material as compound 132. Compound 131 has the ability to convert 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 eventually converted to the singlet excited state of compound 132 and compound 13. 6 excited state (triplet excited state for phosphorescent materials, singlet excited state for TADF materials) It is preferable that energy is transferred to the compound 132 and the compound 136, and the compound 132 and the compound 136 emit light. In the optical layer 130, compound 131 is an energy donor, compound 132 and compound 136 In FIG. 1(C), the light-emitting layer 130 The fluorescent compound 131 is used as a host material, and compounds 132 and 136 are used as guest materials. In other words, in Figure 1(C), the host material is the energy donor, and the guest material is the The light-emitting layer 130 is an embodiment in which the material functions as an energy acceptor. Light emission originating from the starting materials Compound 132 and Compound 136 can be obtained.

[0066] <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. In this example, a TADF material is used for compound 131 and a phosphorescent material is used for compound 136. This shows the case where

[0067] In addition, the compound 131, the compound 132, and the compound 136 in the light-emitting layer 130 The correlation between the energy levels is shown in Figure 1(C). The notations and symbols in Figure 1(C) are as follows: It is as follows: ·Host(131): Compound 131 ·Fluorescent Guest(132): Compound 132 ·Phosphorescent Guest (136): Compound 136 TC1 :T1 level of compound 131 ·S C1 : S1 level of compound 131 ·S FG : S1 level of compound 132 T FG :T1 level of compound 132 T PG : T1 level of compound 136

[0068] 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 FG is Specifically, it is preferable to set the tangent at the tail on the short wavelength side of the fluorescence spectrum of Compound 131. The energy of the wavelength of the extrapolated line is S C1 The absorption spectrum of compound 132 is The energy of the wavelength at the convergence point is S FG When this is done, S C1 ≧S FG It is preferable that In addition, since compound 136 is a phosphorescent material, the singlet excitation energy of compound 131 is and triplet excitation energy can be received (Fig. 1(C) Route A3). , S C1 ≧T C1 ≧T PG It is preferable that the absorption spectrum of Compound 136 is The energy of the wavelength at the convergence point is T PG In addition, the low temperature (e.g. The wavelength energy at the emission edge on the short wavelength side of the emission spectrum at 10 K (for example) is T C1 Seen as It can be done.

[0069] 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. By this, triplet excitation energy can be converted into fluorescent light, and thus the light emission of the light-emitting element can be improved. Furthermore, compound 136 also converts triplet excitation energy into luminescence. Therefore, Compound 132 and Compound 136 emit light of different colors. This makes it possible to efficiently obtain multicolor light emission.

[0070] In the light-emitting layer 130, the compounds 131, 132, and 136 are mixed together. Therefore, triplet excitation of compound 131 is not possible in competition with the above routes A1, A2, and A3. The process of converting the excitation energy of the compound 132 into triplet excitation energy (Fig. 1(C)). Compound 132 is a fluorescent material, so triplet excitation of compound 132 can occur. The photon energy does not contribute to the emission. The light-emitting efficiency of the optical element decreases. C1 From T FG Energy transfer to Process A4 is not directly, but the T FG Once excited to a higher triplet excited state, Energy transfer occurs, and then internal conversion occurs to T FG There is a possible route that leads to this, but in the figure, In the following description, the undesirable thermal deactivation process, i.e. T FG The deactivation process is the same for all of them.

[0071] Also, as shown in Figure 1(C), S FG ≧T PG In this case, the singlet excitation of compound 132 The photoelectron energy is converted into fluorescent light and T PG The process of energy transfer to (Fig. 1 (C) Route A5) competes with compound 136, i.e., compound 136 receives the excitation energy. Routes A3 and A5 exist. Therefore, the emission of compounds 132 and 136 To obtain a good ratio of both, the concentration of compound 132 in the light-emitting layer 130 should be less than that of compound 136. It is preferable that the concentration of the compound 136 in the light-emitting layer 130 is higher than that of the compound 136 in the light-emitting layer 130. is preferred because the carriers are less likely to recombine in compound 136.

[0072] The triplet excitation energy of compound 136 is converted into luminescence and The process by which the triplet excitation energy of 136 is converted to the triplet excitation energy of compound 132 (Figure 1(C) Route A6) can occur in competition. The triplet excitation energy of compound 132 does not contribute to the emission. When energy transfer occurs, the light emitting efficiency of the light emitting element decreases.

[0073] In addition, the shorter the wavelength of the light emitted by a compound, the higher the energy with which it is excited. Therefore, in order to obtain good reliability in a light-emitting element, it is necessary to use a compound that emits light with a short wavelength. It is preferable to use a luminescent material with a high light velocity constant, and it is preferable to use a fluorescent material. In other words, the emission from compound 132 is at a shorter wavelength than the emission from compound 136. It is preferable that the light-emitting element has an emission peak.

[0074] 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 A4 and Route A6 The Dexter mechanism is the dominant mechanism for energy transfer. The distance between compound 131 and compound 136 and the energy acceptor compound 132 is 1 Therefore, in order to suppress Route A4 and Route A6, It is important to increase the distance between the energy donor and the energy acceptor.

[0075] In addition, the singlet excited energy level (S C1 ) from the triplet of compound 132 Excitation energy level (T FG ) is the singlet ground state in compound 132. Since direct transitions from the α-state to the triplet excited state are forbidden, the main energy transfer process is Since this is unlikely to occur, it is not shown in the figure.

[0076] T in Figure 1(C) FG is often an energy level derived from the luminophore of a fluorescent compound. Therefore, in order to suppress route A4 and route A6, the energy It is important to increase the distance between the donor and the luminophore of the fluorescent compound that receives the energy. The method for increasing the distance between the energy donor and the luminophore of the fluorescent compound is In general, the concentration of the fluorescent compound in the mixed film of these compounds is reduced. However, when the concentration of the energy acceptor in the mixed film is reduced, the energy donor Not only the Dexter mechanism of energy transfer from the compound to the fluorescent compound, but also the Förster mechanism In this case, the energy transfer based on the mechanism is also suppressed. Since this is based on a mechanism, problems such as a decrease in the light emitting efficiency and reliability of the light emitting element arise.

[0077] 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. Furthermore, by using the fluorescent material, it was found that the fluorescent material and the phosphorescent material were mixed. It was found that both fluorescent and phosphorescent emissions could be obtained from the combined light-emitting layer.

[0078] <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 compound is dispersed in a host material and a case where the compound is dispersed in a host material. The conceptual diagram shows a fluorescent material with a protective group dispersed as a guest material in a host material. The host material can be interpreted as an energy donor, and the guest material as an energy acceptor. Here, the protecting group has the function of increasing the distance between the luminophore and the host material. In FIG. 2(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 30 2 has a luminophore 310 and a protecting group 320. Also, in FIGS. 2(A) and (B), The material 301 and the guest material 302 are surrounded by a host material 330. The photophore and the host material are close to each other, so the energy is transferred from the host material 330 to the guest material 301. As energy transfer, the Förster mechanism (Fig. 2(A) and (B) shows the energy transfer by Route A7) and energy transfer via the Dexter mechanism (Route A in Figure 2(A) and (B)). 8) Triplet excitation from the host material to the guest material by the Dexter mechanism can occur. When the energy transfer occurs and the triplet excited state of the guest material is generated, When the material is a fluorescent material, the triplet excitation energy is non-radiatively deactivated, and the light-emitting element emits This is one of the causes of reduced light efficiency.

[0079] 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. Therefore, the energy transfer due to the guest material 30 (Route A8) can be suppressed. By using a fluorescent material having a protecting group such as 2 in the light-emitting layer 130 shown in FIG. Routes A4 and A6 in FIG. 1(C) can be suppressed.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] On the other hand, in a light-emitting element according to one embodiment of the present invention, a fluorescent material having a protecting group on a luminophore is used in a light-emitting layer. Therefore, while suppressing the energy transfer by the Dexter mechanism, the Förster mechanism This allows for efficient use of the fluorescent material, which is the energy acceptor, and As a result, the energy transfer by the Dexter mechanism can be suppressed. This allows for the inherently contradictory phenomenon of increasing the energy transfer rate via the Förster mechanism. The concentration of the fluorescent material is 1 wt% or more and 30 wt% or less relative to the host material. % or less, more preferably 5 wt% to 20 wt%, and even more preferably 5 wt% to 50 wt%. By using this composition, the effect of the Förster mechanism can be improved. Since the energy transfer rate can be increased, a light-emitting element with high luminous efficiency can be obtained. Furthermore, a material that can convert triplet excitation energy into luminescence is used as the host material. By utilizing this, it is possible to fabricate fluorescent light-emitting devices with high luminous efficiency equivalent to that of phosphorescent light-emitting devices. In addition, the luminous efficiency can be improved by using a highly stable fluorescent material. Furthermore, the light-emitting element of one embodiment of the present invention can be manufactured using a phosphorescent material. Therefore, both fluorescent and phosphorescent light can be obtained with high luminous efficiency. do.

[0084] 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 not only improves reliability, but also increases the energy transfer rate. This competes with the quenching process caused by impurities. The quenching rate constant of this quenching process increases over time. If the light emitting element is turned off, the rate at which the light emitting element emits light decreases, that is, 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, it is possible to increase the energy transfer rate by the Förster mechanism compared to conventional light-emitting devices. Therefore, the influence of competition with the quenching process can be reduced, and the life of the element can be extended.

[0085] 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 a group of atoms (skeleton) containing aromatic rings on which the dipole vector resides.

[0086] 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.

[0087] The protecting group is a group having a triplet excitation energy higher than the T1 level of the luminophore and the host material. Therefore, it is preferable to use a saturated hydrocarbon group. This is because the triplet excitation energy level of the substituents that do not have a π bond is high. The substituent does not have the function of transporting carriers (electrons or holes). The hydride groups have little effect on the excited state or carrier transport properties of the host material, resulting in luminescence. In addition, the distance between the group and the host material can be increased. In organic compounds that simultaneously have a substituent with a π-conjugated system, the fluorine atom is attached to the substituent with the π-conjugated system. Frontier orbitals {HOMO(Highest Occupied Molecular Orbital (also called the highest occupied orbital) and LUMO (Lowest Unoccupied Momentum Orbital) If there is a lowest unoccupied molecular orbital (also called the lowest unoccupied molecular orbital) In particular, the luminophores often have frontier orbitals. In the energy transfer by the - mechanism, the energy donor and the energy acceptor, HO The overlap of MO and LUMO is important. Therefore, saturated hydrocarbon groups are used as protecting groups. By using this, the frontier orbitals of the host material, which is the energy donor, and the This increases the distance between the frontier orbitals of the guest material, which is the acceptor. Energy transfer via the Dexter mechanism can be suppressed.

[0088] 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.

[0089] 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.

[0090] 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

[0091] <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.

[0092] [ka]

[0093] 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 planar direction and The distance between the anthracene ring and the host material can be increased in both the horizontal and vertical directions. , it is possible to suppress energy transfer via the Dexter mechanism.

[0094] 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.

[0095] 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 present invention, at least one of the atoms constituting the multiple protecting groups (tBu groups in FIG. 3) is condensed. Located directly above one side of a fused heteroaromatic ring or fused heteroaromatic ring (anthracene ring in Figure 3). and at least one of the atoms constituting the plurality of protecting groups is in the fused aromatic ring or is located directly above the other face of the fused heteroaromatic ring. Even if the guest material is dispersed in the host material, the distance between the luminophore and the host material can be increased. This makes it possible to suppress the energy transfer by the Dexter mechanism. Preferably, the tBu group is positioned to cap a luminophore such as an anthracene ring.

[0096] <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 compound 136, and further compound 133. In one embodiment of the present invention, Preferably, compound 132 is a fluorescent material and compound 136 is a phosphorescent material. In this example, Compound 131 and Compound 133 are a combination that form an exciplex.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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

[0102] 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.

[0103] 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: It is as follows: ·Comp(131): Compound 131 ·Comp(133): Compound 133 ·Fluorescent 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 :T1 level of compound 133 ·S FG : S1 level of compound 132 T FG :T1 level of compound 132 ·S E : S1 level of the exciplex T E :T1 level of exciplex

[0104] 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 A9 in Figure 4(C)).

[0105] 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.

[0106] 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 A 10 The singlet excitation energy of the exciplex is rapidly released. This can be transferred to compound 132. (Figure 4(C) Route A 11 ). At this time, S E ≧S FG Route A is preferable. 11 In this case, the exciplex is the energy donor. Compound 132 acts as an energy acceptor. Specifically, the fluorescence of the exciplex Draw a tangent line at the tail of the spectrum on the short wavelength side, and let the energy at the wavelength of that extrapolated line be S. E and The energy of the wavelength at the absorption edge of the absorption spectrum of compound 132 is S FG When this is done, S E ≧S FG In addition, since Compound 136 is a phosphorescent material, it is preferable that the compound It can receive singlet excitation energy and triplet excitation energy from the body (Figure 4 (C) Route A 12 ). That is, S E and T E T from both sides PG The energy transfer to In this case, S E ≧T PG and T E ≧T PG It is preferable that S FG ≧ T PG In this case, the singlet excitation energy of compound 132 is converted into fluorescence. T PG This competes with the process of energy transfer to the compound (Route A5 in Figure 4(C)). 136 is Route A 12 and can receive excitation energy via route A5. Therefore, light emitted from both the compound 132 and the compound 136 can be obtained from the light-emitting layer 130.

[0107] Although not specifically shown, Compound 131 and Compound 133 are converted to Compound 132 and / or Energy transfer to compound 136 is also possible.

[0108] 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 .

[0109] The triplet excitation energy generated in the light-emitting layer 130 is transferred to the S1 level of the exciplex via the above-mentioned route A9. Energy transfer from the 132 to the S1 level (Route A) 11 ) through the compound Therefore, the compound 132 can emit light. By using such a material, the light-emitting efficiency of the light-emitting element can be increased.

[0110] In the light-emitting element of one embodiment of the present invention, Compound 132 contains a fluorescent compound having a protecting group on the luminophore. By using this structure, as described above, Route A 13 and A6 This suppresses the energy transfer via the Dexter mechanism, which suppresses the deactivation of triplet excitation energy. Therefore, a light-emitting element with high luminous efficiency can be obtained.

[0111] Routes A9 to A shown above 11 In this specification, the process is referred to as ExSET (Exc iplex-Singlet Energy Transfer) or ExEF (Ex It is sometimes called plex-enhanced fluorescence. In other words, the light-emitting layer 130 is a layer in which excitation energy is transferred from the exciplex to the fluorescent material. .

[0112] <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.

[0113] 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 FG ) or more. Specifically, Draw a tangent at the short wavelength tail of the emission spectrum of the exciplex using a heavy atom, and extrapolate it. The energy of the wavelength of the line is T E The energy of the wavelength of the absorption edge of the absorption spectrum of compound 132 is S FG When this is done, T E ≧S FG It is preferable that:

[0114] 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 FG ) 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. Depending on the organism, it may be possible to distinguish between fluorescence or phosphorescence.

[0115] 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 example, the compound 133, which is a phosphorescent material, is an energy donor. Since the exciplex acts as a donor, the quantum yield can be either high or low. The energy transfer from the triplet excited energy level of the fluorescent material to the singlet excited energy level of the fluorescent material is The energy transfer is allowed as a transition. Energy transfer from the photoactive material to the fluorescent material occurs by the triplet excitation energy of the energy donor. The energy transfer from the singlet level to the singlet excited energy level of the guest material (energy acceptor) This is a preferable configuration because the energy transfer is an allowable transition. 10 The triplet excitation energy of the exciplex is converted to the 11 Through the process The S1 level (S FG ) can be moved to route A9. and Route A 11 The triplet and singlet excitation energies are transferred to the S1 level of the guest material only through this process. can be moved. Route A 11 In this case, the exciplex is the energy donor. , Compound 132 and / or Compound 136 function as the energy acceptor.

[0116] In the light-emitting element of one embodiment of the present invention, Compound 132 contains a fluorescent compound having a protecting group on the luminophore. By using this structure, as described above, Route A 13 and route A6 This suppresses the energy transfer via the Dexter mechanism, which is shown to be Therefore, a light-emitting element with high luminous efficiency can be obtained.

[0117] <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).

[0118] 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 14 The singlet excitation energy of compound 133 is can be rapidly transferred to compound 132 (Figure 4(D) Route A 15 ).child When S C3 ≧S FG It is preferable that:

[0119] 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. 9 to Route A 11 The triplet excitation energy is transferred to the fluorescent material, compound 132. The route of movement and route A in Figure 4(D) 14 and Route A 15 Move to compound 132 via There are multiple pathways for triplet excitation energy to be transferred to fluorescent materials. This can further increase the luminous efficiency.

[0120] Although not specifically shown, compound 131 to compound 132 and / or compound 136 Energy transfer from compound 133 to compound 136 is also possible. Movement is also possible.

[0121] <Emitting layer configuration example 5> FIG. 5B 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. 5(A) is composed of a compound 131 and a compound 132. and compound 136, and further compound 133. In one embodiment of the present invention, Compound 132 is a fluorescent material having a protecting group, and compound 136 is a phosphorescent material. Compound 133 has the function of converting triplet excitation energy into luminescence. The following describes the case where the compound 133 is a phosphorescent material. The notations and symbols are the same as those shown in FIG. 4(C).

[0122] 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. 5(B) Route A 16 ). In addition, some carriers can be recombined with compound 133.

[0123] 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 compound which is a phosphorescent material is preferably Since 133 acts as an energy donor, the quantum yield can be high or low. When a phosphorescent material is used as compound 133, the triplet excitation energy of the energy donor The energy transfer from the energy level to the singlet excited energy level of the guest material (energy acceptor) This is a preferred configuration because the energy transfer is an allowed transition. Energy to Root A 17 The S1 level (S FG ) Route A 17 In the formula, compound 133 is the energy donor, and compound 132 is the acts as an energy acceptor. In this case, T C3 ≧S FG Then, the compound The excitation energy of 133 is efficiently transferred to the singlet excited state of the guest material, compound 132. Specifically, in the short wavelength tail of the phosphorescence spectrum of Compound 133, Draw a tangent line and calculate the energy of the wavelength of the extrapolated line as T C3 The absorption spectrum of compound 132 The energy of the wavelength at the absorption edge of FG When this is done, T C3 ≧S FG It is preferred to be In addition, since Compound 136 is a phosphorescent material, it is possible to obtain the triplet excited electrons of Compound 133. (Fig. 5(B) Route A 18 ). That is, T C3 From T PG Energy transfer to T C3 ≧T PG It is preferable that , S FG ≧T PG In this case, the singlet excitation energy of compound 132 is converted into fluorescence. The process of exchange and T PG This competes with the process of energy transfer to the Compound 136 can be obtained by Route A.18 and receiving excitation energy via route A5 Therefore, light emission from both compounds 132 and 136 can be obtained from the light-emitting layer 130. can be done.

[0124] Although not specifically shown, compound 131 to compound 132 and / or compound 136 Energy transfer is also possible.

[0125] 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 19 and route A6 This suppresses the energy transfer via the Dexter mechanism, which is shown to be Therefore, a fluorescent light emitting device with high luminous efficiency can be obtained.

[0126] <Configuration Example 6 of Light-Emitting Layer> FIG. 5C 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. 5(A) is composed of a compound 131 and a compound 132. and compound 136, and further compound 133. In one embodiment of the present invention, Compound 132 is a fluorescent material having a protecting group, and compound 136 is a phosphorescent material. Compound 133 has the function of converting triplet excitation energy into luminescence. The following describes the case where Compound 133 is a compound having TADF properties. The notations and symbols in (C) are the same as those shown in FIG. 4(C).

[0127] 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 T C3 (Fig. 5(C) Route A 20 ). In addition, some The carrier can recombine with compound 133.

[0128] Here, compound 133 is a TADF material, so it upconverts triplet excitation energy. It has the function of converting it into singlet excitation energy by the reaction (Fig. 5(C) Route A 21 ) In addition, the singlet excitation energy of compound 133 is rapidly transferred to compound 132. (Fig. 5(C) Route A 22 ). At this time, S C3 ≧S FG Yes Specifically, it is preferable that the tangent line at the short wavelength side of the fluorescence spectrum of Compound 133 is and the energy of the wavelength of the extrapolated line is S C3 and the absorption spectrum of compound 132 The energy of the wavelength at the absorption edge is S FG When this is done, S C3 ≧S FG It is preferable that: Route A 20 Route A 22 The triplet excitation energy in the light-emitting layer 130 is Ghee can be converted to the fluorescence of compound 132. Route A 22 In the compound Compound 133 functions as an energy donor, and compound 132 functions as an energy acceptor. In addition, since compound 136 is a phosphorescent material, the singlet excitation energy of compound 133 is and triplet excitation energy (Figure 5(C) Route A 23 ).vinegar That is, S C3 and T C3 T from both sides PG Energy transfer to S FG ≧T PG In this case, the singlet excitation energy of compound 132 is converted into fluorescence. Process and T PG This competes with the process of energy transfer to the compound (Route A5 in Figure 5(C)). Item 136 is Route A 23 and can receive excitation energy via route A5 Therefore, light from both the compound 132 and the compound 136 can be obtained from the light-emitting layer 130. .

[0129] Although not specifically shown, compound 131 to compound 132 and / or compound 136 Energy transfer is also possible.

[0130] 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 and route A6 This suppresses the energy transfer via the Dexter mechanism, which is shown to be Therefore, a fluorescent light emitting device with high luminous efficiency can be obtained.

[0131] <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.

[0132] <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).

[0133]

number

[0134] 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.

[0135] 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.

[0136]

number

[0137] 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.

[0138] 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 nrepresents 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.

[0139]

number

[0140] 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.

[0141] <Concept for enhancing energy transfer> First, consider the energy transfer via the Förster mechanism. Substituting equation (1) into equation (3), 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.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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 converted 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.

[0146] 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:

[0147] 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.

[0148] 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. Emitting triplet excited state energy such as photoactive materials, exciplexes, or TADF materials The first material can transfer 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 promotes reverse intersystem crossing from the triplet excited state to the singlet excited state of the TADF material, The excited lifetime τ of the triplet excited state of the first material can be shortened. The conversion from the triplet excited state of an exciplex (using a photoluminescent or phosphorescent material) to the singlet ground state This can accelerate the transition and shorten the excited lifetime τ of the triplet excited state of the first material. As a result, the triplet excited state of the first material is converted to the triplet excited state of the fluorescent material (second material). This can reduce the efficiency of energy transfer in the Dexter mechanism to

[0149] 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.

[0150] <Material> Next, components of a light-emitting element according to one embodiment of the present invention will be described in detail below.

[0151] <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. The triplet excitation is achieved by using an energy acceptor and an energy donor with a protecting group on the luminophore. Materials that have the function of converting photovoltaic energy into light include TADF materials and phosphorescent materials. Examples include:

[0152] The luminophores contained in the compound 132 that function as energy acceptors include, for example, fluorophores. 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 compounds with a benzofuran skeleton, quinacridone skeleton, or naphthobisbenzofuran skeleton have high fluorescence intensity. This is preferred because of the high molecular yield.

[0153] 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.

[0154] 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.

[0155] 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. C1 to C6 groups such as sec-butyl, tert-butyl, pentyl, and hexyl groups 7 alkyl groups, cyclopentyl groups, cyclohexyl groups, cycloheptyl groups, 8,9, cycloalkyl groups having 5 to 7 carbon atoms, such as 10-trinorbornanyl groups, and phenyl groups. and aryl groups having 6 to 12 carbon atoms such as a naphthyl group and a biphenyl group.

[0156] 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.

[0157] 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.

[0158] 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 there is.

[0159] 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.

[0160] 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.

[0161] 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 a structure having protecting groups at the 3- and 5-positions.

[0162] 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.

[0163] Examples of the energy acceptor described above include those represented by the following general formula (G1) or The organic compound represented by (G2) can be suitably used.

[0164] [ka]

[0165] 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;

[0166] 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.

[0167] 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.

[0168] In addition, in the general formula (G2), the protecting group is connected to the quinacridone skeleton, which is the luminophore, via the arylene group. By adopting this structure, the protecting group is arranged to cover the luminophore. Therefore, it is possible to suppress the energy transfer by the Dexter mechanism. The luminophore may have a protecting group that is directly bonded to the luminophore.

[0169] 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.

[0170] [ka]

[0171] 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 12 are 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; represents any one of the aryl groups.

[0172] It is also preferable that the protecting group is bonded to the luminophore via a phenyl group. By this, the protecting group can be placed to cover the luminophore, and the Dexter mechanism In addition, the luminophore and the protecting group are connected via the phenylene group. When two protecting groups are bonded to the phenylene group, the phenylene group is represented by the general formulas (G3) and (G As shown in 4), the two protecting groups are bonded at the meta position relative to the phenylene group. This structure allows the luminophores to be covered efficiently, and thus the dextromethorphan The organic compound represented by general formula (G3) can suppress the energy transfer by the electron transport mechanism. An example of the compound is the above-mentioned 2tBu-mmtBuDPhA2Anth. That is, in one embodiment of the present invention, general formula (G3) is a particularly preferred example.

[0173] The energy acceptor material is an organic compound represented by the following general formula (G5): The material can be suitably used.

[0174] [ka]

[0175] In general formula (G5), X1 ~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.

[0176] 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.

[0177] 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.

[0178] 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.

[0179] [ka]

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[0188]

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[0200] 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.

[0201] [ka]

[0202] 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 less than or equal to 0.2 eV. Compound 136 also contains TA DF materials can be used.

[0203] Compound 133 and / or Compound 136 have a skeleton with hole transporting properties and a skeleton with electron transporting properties. Alternatively, Compound 133 and / or Compound 1 are preferably 36 may have a π-electron rich skeleton or an aromatic amine skeleton and a π-electron deficient skeleton. This is preferable. By doing so, it becomes easier to form a donor-acceptor type excited state within the molecule. Furthermore, the donor and acceptor functions are present in the molecules of Compound 133 and / or Compound 136. The structure is such that the skeleton having electron transport property and the skeleton having hole transport property are directly arranged so that both the electron transport property and the hole transport property are strong. Alternatively, it is preferable that the structure has a π-electron-rich skeleton or an aromatic amine. It is preferable that the skeleton and the π-electron-deficient skeleton have a structure in which they are directly bonded. By strengthening both the acceptor and the acceptor properties, the H of compound 133 and / or compound 136 The region where the molecular orbitals in the OMO are distributed and the region where the molecular orbitals in the LUMO are distributed The overlap of the two compounds can be reduced, and the singlet excitation of compound 133 and / or compound 136 can be reduced. It is possible to reduce the energy difference between the energy level and the triplet excited energy level. In addition, the triplet excited energy level of Compound 133 and / or Compound 136 can be increased. It is possible to keep the energy

[0204] When a TADF material is composed of one type of material, for example, the following materials can be used: can.

[0205] 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.

[0206] [ka]

[0207] In addition, TADF materials consisting of a single material include those with a π-electron-rich skeleton and a π-electron-deficient skeleton. Heterocyclic compounds having one or both of the foot structures can also be used. (biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-1,2 ... 2-{4-(4-benzol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), -[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazole-9- yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPT zn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4,6-difluoro Phenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4-(5-phenyl -5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1, 2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-azabicyclo[4.2.1.2]phenyl) cridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN), bis[ 4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridine-9,9 '-anthracen]-10'-one (abbreviation: ACRSA), 4-(9'-phenyl-3, 3'-bi-9H-carbazol-9-yl)benzofuro[3,2-d]pyrimidine (abbreviation :4PCCzBfpm), 4-[4-(9'-phenyl-3,3'-bi-9H-carbazo (4PCCzP Bfpm), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl] [phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPT The heterocyclic compound includes a π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring. Since it has a toe-shaped heteroaromatic ring, it has high electron transport properties and hole transport properties, and is therefore preferred. Among the skeletons with electron-deficient heteroaromatic rings, pyridine skeleton, diazine skeleton (pyrimidine skeleton) The pyrazine skeleton, pyridazine skeleton, and triazine skeleton are stable and reliable. In particular, benzofuropyrimidine skeleton, benzothienopyrimidine skeleton, benzo The furopyrazine and benzothienopyrazine skeletons have high acceptor properties and are highly reliable. Among the skeletons having a π-electron-rich heteroaromatic ring, acridine skeletons, Phenoxazine skeleton, phenothiazine skeleton, furan skeleton, thiophene skeleton, and pyrrole The skeleton is stable and reliable, so it is preferable to have at least one of the skeletons. The furan skeleton is a dibenzofuran skeleton, and the thiophene skeleton is a dibenzothiophene skeleton. The pyrrole skeleton is preferably an indole skeleton or a carboxyl skeleton. Carbazole skeleton, bicarbazole skeleton, 3-(9-phenyl-9H-carbazole-3-yl) A π-electron rich heteroaromatic ring and a π-electron rich heteroaromatic ring are particularly preferred. The substance in which the π-deficient heteroaromatic ring is directly bonded exhibits the donor property of the π-electron rich heteroaromatic ring and the π-electron The acceptor properties of the deficient heteroaromatic rings are both strong, and the levels of the singlet excited state and the triplet excited state In addition, instead of the π-electron deficient heteroaromatic ring, Alternatively, an aromatic ring having an electron-withdrawing group such as a cyano group bonded thereto may be used.

[0208] [ka]

[0209] When Compound 133 does not have the function of converting triplet excitation energy into luminescence, Compound 1 A combination of 31 and compound 133 that forms an exciplex with each other is preferred. However, there is no particular limitation. One has a function of transporting electrons, and the other has a function of transporting holes. This is preferable.

[0210] 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.

[0211] In addition, the following hole transporting materials and electron transporting materials can be used.

[0212] 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.

[0213] 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.

[0214] 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:

[0215] 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.

[0216] 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.

[0217] 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.

[0218] 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.

[0219] 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-9-H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1B P), 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: PCB NBB), 4-phenyldiphenyl-(9-phenyl-9H-carbazol-3-yl) Amine (abbreviation: PCA1BP), N,N'-bis(9-phenylcarbazol-3-yl) )-N,N'-diphenylbenzene-1,3-diamine (abbreviation: PCA2B), N,N' ,N''-triphenyl-N,N',N''-tris(9-phenylcarbazole-3- N-(4-biphenylyl)benzene-1,3,5-triamine (abbreviation: PCA3B), )-N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carboxylate PCBiF, N-(1,1'-biphenyl-4-yl) )-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9- Dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF), 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-carbazole-9- N-(4-phenyl)phenyl]-N-(4-phenyl)phenylaniline (abbreviation: YGA1BP), ,N'-Bis[4-(carbazol-9-yl)phenyl]-N,N'-diphenyl-9 Aromatic amines such as 9-dimethylfluorene-2,7-diamine (abbreviation: YGA2F) Compounds such as 3-[4-(1-naphthyl)-phenyl]-9- Phenyl-9H-carbazole (abbreviation: PCPN), 3-[4-(9-phenanthryl) -phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPPn), 3,3'-biphenyl PCCP, 1,3-bis(N-carbazole) 3,6-bis(3,5-diphenylphenyl)- 9-Phenylcarbazole (abbreviation: CzTP), 4-{3-[3-(9-phenyl-9H -fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFL Bi-II), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzo furan) (abbreviation: DBF3P-II), 1,3,5-tri(dibenzothiophene-4-yl) 2,8-diphenyl-4-[4-(9-phenyl)-benzene (abbreviation: DBT3P-II) (phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTF LP-III), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl] -6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), 4-[3-(trifluoromethyl)- (2-phenylen-2-yl)phenyl]dibenzothiophene (abbreviation: mDBTPTp-II), etc. Amine compounds, carbazole compounds, thiophene compounds, furan compounds, fluorenated compounds Compounds, triphenylene compounds, phenanthrene compounds, etc. can be used. Solid materials are 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 an electron transporting property.

[0220] 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.

[0221] 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 phenyl)pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[ 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.

[0222] Compound 133 is preferably a material that can form an exciplex with compound 131. The hole transporting material and electron transporting material shown above can be used for the layer. In this case, the emission peak of the exciplex formed by Compound 131 and Compound 133 is Compound 131 was added so as to overlap with the absorption band on the longest wavelength side (lowest energy side) of the fluorescent material. It is preferable to select Compound 133 and Compound 132 (fluorescent material). As a result, a light-emitting element with dramatically improved luminous efficiency can be obtained.

[0223] Furthermore, a phosphorescent material can be used as compound 133 and / or compound 136. Phosphorescent materials include organometallic complexes of iridium, rhodium, or platinum, In addition, platinum complexes with porphyrin ligands and organic iridium complexes are also available. Among them, organic iridium complexes such as iridium orthometal complexes are exemplified. The orthometalated ligands include 4H-triazole ligands, 1H-triazole ligands, and Riazole ligands, imidazole ligands, pyridine ligands, pyrimidine ligands, pyrazine In this case, compound 133 (phosphorescent triplet MLCT (Metal to Ligand Charge Tran) The emission peak of compound 133 is the same as that of compound 132 (fluorescent transition). Compound 133 was added so as to overlap with the absorption band on the longest wavelength side (lowest energy side) of the photosensitive material. It is preferable to select Compound 132 (fluorescent material). This will dramatically increase the luminous efficiency. In addition, when the compound 133 is a phosphorescent material, Even if the compound 131 is used, it may form an exciplex with the compound 131. When the compound 131 forms an exciplex, The material does not need to emit light at room temperature, but only needs to emit light at room temperature when an exciplex is formed. In the case of, for example, tris[2-(1H-pyrazol-1-yl-κN 2 ) Phenyl-κC ] Iridium (III) (abbreviation: Ir(ppz)3) and other phosphorescent materials are used. In addition, the emission peak of compound 132 is on the longest wavelength side (low energy) of compound 136. It is preferable to select compounds 132 and 136 so that they overlap with the absorption bands of the other two (the ion-exchange side). This makes it possible to fabricate a multicolor light-emitting device with good luminous efficiency.

[0224] Examples of substances having an emission peak in the blue or green wavelength region include tris{2- [5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4 -triazol-3-yl-κN 2 ]phenyl-κC}iridium(III) (abbreviation: I r(mpptz-dmp)3), tris(5-methyl-3,4-diphenyl-4H-1, 2,4-triazolato)iridium(III) (abbreviation: Ir(Mptz)3), tris[ 4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triacontria Zolato]iridium(III) (abbreviation: Ir(iPrptz-3b)3), tris[3- (5-biphenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazola 4H-triazolidinediamine (Triazolidinediamine) such as iridium(III) (abbreviation: Ir(iPr5btz)3), Organometallic iridium complexes with zole skeletons and tris[3-methyl-1-(2-methyl phenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III)( Abbreviation: Ir(Mptz1-mp)3), tris(1-methyl-5-phenyl-3-propionyl Ir(PrPrTz)triazolatoiridium(III) Organometallic iridium complexes with 1H-triazole skeletons, such as 1-Me)3), and f ac-Tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imida Iridium(III) (abbreviation: Ir(iPrpmi)3), tris[3-(2, 6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]yl Imidazole skeleton, such as Ir(dmpimpt-Me)3 Organometallic iridium complexes containing bis[2-(4',6'-difluorophenyl)pi Lysinato-N,C 2’ ]iridium(III) tetrakis(1-pyrazolyl)borate( Abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ ]iridium(III) picolinate (abbreviation: Firpic), bis{2-[3', 5'-Bis(trifluoromethyl)phenyl]pyridinato-N,C 2’}Iridium (I II) Picolinate (abbreviation: Ir(CF3ppy)2(pic)), bis[2-(4', 6'-Difluorophenyl)pyridinato-N,C 2’ ]Iridium(III) acetylacetone Phenylpyridines with electron-withdrawing groups such as setonate (abbreviation: FIr(acac)) Among the above, 4H-thiazolium derivatives are used as ligands. Nitrogen-containing five-membered complexes such as triazole, 1H-triazole and imidazole skeletons Organometallic iridium complexes with heterocyclic skeletons have high triplet excitation energies and are highly reliable. It is particularly preferable because it has excellent luminous efficiency.

[0225] Furthermore, examples of substances having an emission peak in the green or yellow wavelength region include tris (4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: Ir(mpp m)3), tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (Abbreviation: Ir(tBuppm)3), (acetylacetonato)bis(6-methyl-4-furan) (phenylpyrimidinato)iridium(III) (abbreviation: Ir(mppm)2(acac)) , (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)i Lithium(III) (abbreviation: Ir(tBuppm)2(acac)), (acetylacetonate Nato)bis[4-(2-norbornyl)-6-phenylpyrimidinato]iridium(II I) (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(aca c)), (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium ( III) Ir(dppm)2(acac) and other compounds having a pyrimidine skeleton Organic metal iridium complexes and (acetylacetonato)bis(3,5-dimethyl-2-phenyl) Rupirazinato)iridium(III) (abbreviation: Ir(mppr-Me)2(acac)) , (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazine g) Iridium(III) (abbreviation: Ir(mppr-iPr)2(acac)) Organometallic iridium complexes with pyrazine skeletons and tris(2-phenylpyridinato-N ,C 2’ ) Iridium(III) (abbreviation: Ir(ppy)3), bis(2-phenylpyridine) Ginat-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(ppy )2(acac)), bis(benzo[h]quinolinato)iridium(III) acetylacetone Setonate (abbreviation: Ir(bzq)2(acac)), tris(benzo[h]quinolinate ) Iridium(III) (abbreviation: Ir(bzq)3), tris(2-phenylquinolinato -N,C 2’ ) Iridium(III) (abbreviation: Ir(pq)3), bis(2-phenylquinoxadiene) Norinato-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(pq )2(acac)) and organometallic iridium complexes with pyridine skeletons, such as bis(2 ,4-Diphenyl-1,3-oxazolato-N,C 2’ ) Iridium(III) acetyl Acetonate (abbreviation: Ir(dpo)2(acac)), bis{2-[4'-(perfluorooctyl) (O-phenyl)phenyl]pyridinato-N,C 2’}Iridium(III) acetylacetone Tonanate (abbreviation: Ir(p-PF-ph)2(acac)), bis(2-phenylbenzo[a] Thiazolato-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(b In addition to organometallic iridium complexes such as tris(acetylacetonato) (Monophenanthroline)terbium(III) (abbreviation: Tb(acac)3(Phen Among the above, rare earth metal complexes having a pyrimidine skeleton are Organometallic iridium complexes are particularly preferred because they are remarkably excellent in reliability and luminous efficiency.

[0226] Furthermore, examples of substances having an emission peak in the yellow or red wavelength region include (diphenyl ether) Sobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridine Ir(III) (abbreviation: Ir(5mdppm)2(dibm)), bis[4,6-bis( 3-methylphenyl)pyrimidinato](dipivaloylmethanato)iridium(III)( Abbreviation: Ir(5mdppm)2(dpm)), bis[4,6-di(naphthalene-1-yl )pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: Ir(d1n Organometallic iridium complexes with pyrimidine skeletons, such as (pm)2(dpm)), Cetylacetonato)bis(2,3,5-triphenylpyrazinato)iridium(III) (abbreviation: Ir(tppr)2(acac)), bis(2,3,5-triphenylpyrazine) Ir(tppr)2(dp) m)), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxa linato]iridium(III) (abbreviation: Ir(Fdpq)2(acac)), bis{4, 6-dimethyl-2-[5-(2,6-dimethylphenyl)-3-(3,5-dimethylphenyl] {2,2',6,6'-tetramethyl-2-pyrazinyl-κN}phenyl-κC}(2,2',6,6'-tetramethyl -3,5-heptanedionato-κ2O,O')iridium(III) (abbreviation: Ir(dm Organometallic iridium complexes with pyrazine skeletons, such as dppr-dmp2(dpm) Tris(1-phenylisoquinolinato-N,C 2’ ) Iridium(III) (abbreviation :Ir(piq)3), bis(1-phenylisoquinolinato-N,C 2’ )iridium( III) Pyridyl acetylacetonates such as Ir(piq)2(acac) In addition to organometallic iridium complexes with iridium skeletons, 2,3,7,8,12,13,17,18 -octaethyl-21H,23H-porphyrin platinum(II) (abbreviation: PtOEP) Platinum complexes such as tris(1,3-diphenyl-1,3-propanedionato) (monophenyl (anthroline) europium(III) (abbreviation: Eu(DBM)3(Phen)), tri bis[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthro rare earths such as (phosphorus) europium(III) (abbreviation: Eu(TTA)3(Phen)) Among the above, organometallic iridium complexes having a pyrimidine skeleton are The pyrazine structure is particularly preferred because it is remarkably excellent in reliability and luminous efficiency. The organometallic iridium complex having the above structure can emit red light with good chromaticity.

[0227] 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).

[0228] (SA)MX3:(g1) (LA)2(SA) n-1 M n X 3n+1 :(g2) (PA)(SA) n-1 M n X3 n+1 :(g3)

[0229] In the above general formula, M represents a divalent metal ion, and X represents a halogen ion.

[0230] Specifically, divalent cations such as lead and tin are used as divalent metal ions.

[0231] Specifically, anions of chlorine, bromine, iodine, fluorine, etc. are used as halogen ions. I can.

[0232] 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.

[0233] Also, LA is R 30 -NH3 + represents an ammonium ion represented by the formula:

[0234] 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, alkylene groups, vinylene groups, arylene groups and heteroaryl groups are included. A plurality of olefin groups may be connected, or a plurality of groups of the same type may be used. The alkylene group, vinylene group, arylene group, and heteroarylene group are linked together. In this case, the total number of alkylene groups, vinylene groups, arylene groups, and heteroarylene groups shall be 35 or less. Preferably, it is below.

[0235] SA is a monovalent metal ion or R 31 -NH3 + and R 31 carbon number 1 to 6 alkyl group represents an ammonium ion.

[0236] 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. .

[0237] 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.

[0238] 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.

[0239] [ka]

[0240] [ka]

[0241] 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.

[0242] [ka]

[0243] [ka]

[0244] However, in the above general formula, R 20 represents an alkyl group having 2 to 18 carbon atoms, and R21 , 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.

[0245] [ka]

[0246] These are just examples, and the substances that can be used as (LA) and (PA) are not listed here. It is not limited to.

[0247] 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.

[0248] 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.

[0249] In addition, in the light-emitting layer 130, materials other than the compounds 131, 132, and 133 In this case, Compound 131 and Compound 133 are effective. To form an exciplex, the HOMO of either compound 131 or compound 133 must be The HOMO level of the material in the light-emitting layer 130 is the highest, and the LUMO level of the other material is It is preferable that the material in the light-emitting layer 130 has the lowest LUMO level. The reaction of compound 131 and compound 135 to form an exciplex is shown by the correlation of the Gamma level. can be suppressed.

[0250] For example, when compound 131 has hole transport properties and compound 133 has electron transport properties, The HOMO level of compound 131 is the same as that of compound 133 and that of compound 135. The LUMO level of compound 133 is preferably higher than the LUMO level of compound 131. It is preferable that the LUMO level of the compound 135 is lower than that of the compound 135. The LUMO level of compound 5 may be higher or lower than the LUMO level of compound 131. The HOMO level of compound 135 may be higher or lower than the HOMO level of compound 133.

[0251] 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'- Diphenanthrene (DPNS), 9,9'-(stilbene-4,4'-diphenyl) yl)diphenanthrene (abbreviation: DPNS2), 3,3',3''-(benzene-1,3 ,5-triyl)tripylene (abbreviation: TPB3), etc. Among these and known substances, compounds with energy gaps smaller than those of Compound 131 and Compound 132 were selected. It is sufficient to select and use one or more materials that have a larger energy gap than the .

[0252] <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.

[0253] 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 -2 Electrically 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.

[0254] 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.

[0255] 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.

[0256] <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).

[0257] 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.

[0258] 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.

[0259] 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.

[0260] 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.

[0261] 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.

[0262] <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.

[0263] 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.

[0264] ≪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.

[0265] 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.

[0266] ≪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 transport material can be used. 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 .

[0267] The electron injection layer 119 may contain a composite material formed by mixing an organic compound and an electron donor (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.

[0268] 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.

[0269] 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.

[0270] 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.

[0271] Furthermore, examples of polymer compounds that can be used in the light-emitting layer include poly[2-methacrylamide] and poly[2-methyl-2-propanol]. 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.

[0272] <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.

[0273] 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. Anything other than these can be used as long as it functions as a support in the manufacturing process of the filter, etc. Alternatively, it is sufficient if it has a function of protecting the light emitting element and the optical element.

[0274] For example, in this specification, 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., a single crystal crystal substrate or silicon substrate), SOI substrate, glass substrate, quartz substrate, plastic substrate, gold Metal substrate, stainless steel substrate, substrate with stainless steel foil, tungsten Tungsten substrate, substrate with tungsten foil, flexible substrate, laminated film, fiber These include cellulose nanofibers (CNF), paper, and base films containing such materials. Examples of glass substrates include barium borosilicate glass, aluminoborosilicate glass, and Soda lime glass is used for flexible substrates, laminated films, base films, etc. Examples of such materials include polyethylene terephthalate (PET), Polyethylene naphthalate (PEN), polyethersulfone (PES), polytetrafluoroethylene Examples of plastics include fluoroethylene (PTFE). Resins such as acrylic, etc., or examples include polypropylene, polyester, Examples include polyvinyl fluoride and polyvinyl chloride. Alternatively, examples include polyamide. , polyimide, aramid, epoxy, inorganic vapor deposition film, or paper.

[0275] 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.

[0276] 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.

[0277] 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.

[0278] As described above, the structure shown in this embodiment mode can be used in appropriate combination with other embodiment modes. Cut.

[0279] (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.

[0280] <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, it can be produced by the synthesis schemes (S-1) and (S-2) shown below. 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.

[0281] 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.

[0282] [ka]

[0283] [ka]

[0284] 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.

[0285] 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 trifluoride 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.

[0286] 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.

[0287] 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.

[0288] 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. It is preferable to react the coupling product with compound 6.

[0289] (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. 6. In FIG. 6, 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.

[0290] <Configuration example 2 of light-emitting element> FIG. 6 is a schematic cross-sectional view of the light emitting element 250. As shown in FIG.

[0291] The light-emitting element 250 shown in FIG. 6 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.

[0292] In addition, in the light-emitting element 250 shown in FIG. 6, 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.

[0293] 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.

[0294] 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.

[0295] 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.

[0296] 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.

[0297] 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.

[0298] 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. .

[0299] 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.

[0300] 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.

[0301] In addition, although the light emitting element having two light emitting units has been described with reference to FIG. 6, 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.

[0302] 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.

[0303] 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.

[0304] 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 and a phosphorescent material. Therefore, one or both of the light-emitting layer 120 and the light-emitting layer 170 may be a TADF material. On the other hand, by using the configuration of the light-emitting layer 130 shown in the first embodiment, it is possible to obtain a light-emitting device having high efficiency and high reliability. Thus, a light-emitting element that emits multicolor light can be obtained.

[0305] 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. When a plurality of light-emitting units are provided, the plurality of light-emitting units can be lighted with a small current value. This configuration can be used to adjust the color of emitted light. In particular, when guest materials with different luminous efficiencies and different luminescent colors are used, For example, when the light-emitting unit has three layers, the light-emitting unit has fluorescent materials of the same color. The light-emitting unit has two layers, and the light-emitting unit has a phosphorescent material that emits light of a different color from the fluorescent material. By using a single knit layer, the intensity of fluorescent and phosphorescent light can be adjusted. That is, the intensity of the emitted color can be adjusted by changing the number of light-emitting units.

[0306] 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 Two layers of light-emitting units containing yellow fluorescent materials and one layer of light-emitting unit containing yellow phosphorescent materials. a light-emitting element having two layers of light-emitting units containing a blue fluorescent material and a light-emitting element having two layers of 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 or a light-emitting unit containing a blue fluorescent material. The knit has two layers and a light-emitting unit including a red phosphorescent material, a yellow phosphorescent material, and a green phosphorescent material. A light-emitting device having one layer is preferable because it can efficiently emit white light. The light-emitting element of one embodiment of the present invention can be appropriately combined with a phosphorescent-light-emitting layer.

[0307] 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.

[0308] Note that this embodiment mode can be combined with other embodiment modes as appropriate.

[0309] (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. 7(A) and FIG. 7(B).

[0310] FIG. 7(A) is a top view showing a light-emitting device, and FIG. 7(B) is a cross-sectional view of FIG. 7(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 .

[0311] 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.

[0312] 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.

[0313] 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.

[0314] 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.

[0315] 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.

[0316] 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.

[0317] 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).

[0318] 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.

[0319] 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 third 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 third embodiments is used. The light-emitting element may include both a light-emitting element and a light-emitting element having other configurations.

[0320] 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.

[0321] 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.

[0322] As described above, the light-emitting device using the light-emitting elements described in the first and third embodiments can be obtained.

[0323] <Configuration example 1 of light-emitting device> FIG. 8 shows an example of a display 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.

[0324] FIG. 8A 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 1025, EL layer 1028, light-emitting element 10, a second electrode 1029, a sealing substrate 1031, a sealing material 1032, and the like are shown.

[0325] 8(A) and 8(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. 8(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.

[0326] In FIG. 8B, 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. 8(B), the colored layer may be provided between the substrate 1001 and the sealing substrate 1031. stomach.

[0327] 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.

[0328] <Configuration Example 2 of Light-Emitting Device> Cross-sectional views of a top-emission type light-emitting device are shown in Figures 9(A) and 9(B). The substrate 1001 can be a light-impermeable substrate. The process is the same as that of a bottom emission type light emitting device until the connection electrodes are formed. Thereafter, a third interlayer insulating film 1037 is formed to cover the electrode 1022. The third interlayer insulating film 1037 may have a flattening effect. In addition to the materials similar to those mentioned above, various other materials can be used.

[0329] 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 (B), the lower electrode 1025W, The electrode 1025R, the lower electrode 1025G, and the lower electrode 1025B are preferably 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 electrode A microcavity structure is applied between the top electrode 1025G and the bottom electrode 1025B to generate a specific wavelength. It is preferable that the EL layer 1028 has a function of amplifying light. The device has a configuration as explained in the third embodiment, and has an element structure that can emit white light.

[0330] In Figs. 8(A), 8(B), 9(A) and 9(B), white light is emitted. The L layer may be configured using multiple light-emitting layers or multiple light-emitting units. However, the configuration for obtaining white light emission is not limited to these.

[0331] In the top emission structure shown in Fig. 9(A) and Fig. 9(B), the colored layer (red colored layer 1) A sealing substrate 103 is provided with a green colored layer 1034R, a green colored layer 1034G, and a blue colored layer 1034B. The sealing substrate 1031 is provided with a plurality of insulating layers 1032 disposed between the pixels. A black layer (black matrix) 1030 may be provided. 4R, green colored layer 1034G, blue colored layer 1034B) and black layer (black matrix The sealing substrate 1031 may be covered with an overcoat layer. A substrate having the following structure is used.

[0332] In addition, although FIG. 9(A) shows a configuration for full color display using three colors, red, green, and blue, As shown in B), a full color display using four colors, red, green, blue, and white, may be performed. The full-color display configuration is not limited to these. For example, a full-color display using four colors of red, green, blue, and yellow may be used. A full color display may be performed.

[0333] The light-emitting element according to one embodiment of the present invention includes a fluorescent material and a phosphorescent material or a T By using the ADF material, it is possible to obtain highly efficient multicolor light emission. By using the light-emitting element in the light-emitting device shown in the embodiment, a light-emitting device with high luminous efficiency can be obtained. It is possible.

[0334] As described above, the light-emitting device using the light-emitting elements described in the first and third embodiments can be obtained.

[0335] Note that this embodiment mode can be combined with other embodiment modes as appropriate.

[0336] (Embodiment 5) In this embodiment, an electronic device and a display device according to one embodiment of the present invention will be described.

[0337] 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.

[0338] 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.

[0339] The mobile information terminal 900 shown in FIGS. 10A and 10B includes a housing 901, a housing 902, a display unit 9 03, and a hinge portion 905.

[0340] 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. 10(A)) as shown in Fig. 10(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.

[0341] 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.

[0342] 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.

[0343] 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 903, the portable information terminal 900 can be used as an e-book reader. It can be used as a terminal.

[0344] 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.

[0345] The display unit 903 functions as a touch panel and can be operated with a finger or a stylus. can.

[0346] 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.

[0347] 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.

[0348] 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.

[0349] 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.

[0350] 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.

[0351] A portable information terminal 910 shown in FIG. 10C 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.

[0352] 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.

[0353] 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.

[0354] 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.

[0355] 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.

[0356] 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.

[0357] The camera 920 shown in FIG. 10(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.

[0358] 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.

[0359] 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.

[0360] 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

[0361] The camera 920 can be equipped with a strobe device, a viewfinder, etc. Alternatively, these may be incorporated into the housing 921.

[0362] FIG. 11(A) is a schematic diagram showing an example of a cleaning robot.

[0363] 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.

[0364] 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.

[0365] 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.

[0366] 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.

[0367] 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 out at.

[0368] The light-emitting device according to one embodiment of the present invention can be used for the display 5101 .

[0369] The robot 2100 shown in FIG. 11(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.

[0370] 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.

[0371] 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.

[0372] 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.

[0373] The light-emitting device according to one embodiment of the present invention can be used for the display 2105 .

[0374] FIG. 11C is a diagram showing an example of a goggle-type display. The goggle-type display includes, for example, a housing 5000, a display unit 5001, and a speaker 5003. , LED lamp 5004, operation keys 5005 (including a power switch or an operation switch) , connection terminal 5006, sensor 5007 (force, displacement, position, velocity, acceleration, angular velocity, rotation speed , distance, light, liquid, magnetic, temperature, chemical, sound, time, hardness, electric field, current, voltage, power, (including those that measure radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays), Microphone 5008, second display unit 5002, support unit 5012, earphone 5013, etc. Has.

[0375] 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.

[0376] 12(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 12(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.

[0377] 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.

[0378] 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.

[0379] This embodiment mode can be combined with other embodiment modes as appropriate.

[0380] (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. 13. 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.

[0381] 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. It is possible to realize electronic devices and lighting devices having light-emitting regions.

[0382] 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.

[0383] FIG. 13 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.

[0384] 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.

[0385] In this manner, a lighting device and an electronic device can be obtained by applying the light-emitting device 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.

[0386] The structure described in this embodiment mode may be used in appropriate combination with structures described in other embodiments. You can be there. [Example]

[0387] 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 and 2. The structures and abbreviations of the compounds used are shown below.

[0388] [ka]

[0389] [Table 1]

[0390] [Table 2]

[0391] <Fabrication of light-emitting devices> A method for manufacturing the light-emitting element manufactured in this example will be described below.

[0392] <Fabrication of Light-Emitting Device 1> 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).

[0393] 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.

[0394] 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

[0395] Next, a light-emitting layer 130 containing 4,6mCzP2Pm and Ir(p pz)3 and 2-trimethylsilyl-N,N,N',N'-tetrakis(3,5-di-t ert-butylphenyl)-9,10-anthracene diamine (abbreviation: 2TMS-mmt BuDPhA2Anth) and Ir(dmdppr-dmp)2(dpm) in a weight ratio of 4 ,6mCzP2Pm:Ir(ppz)3:2TMS-mmtBuDPhA2Anth:I r(dmdppr-dmp)2(dpm)) to 0.8:0.2:0.025:0.01 The luminescent layer 130 was co-deposited to a thickness of 40 nm. ,6mCzP2Pm and Ir(ppz)3 are combinations that form exciplexes. MS-mmtBuDPhA2Anth is a fluorescent material with a protecting group, and Ir(dmd ppr-dmp)2(dpm) is a phosphorescent material containing Ir.

[0396] 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.

[0397] 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.

[0398] 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. Specifically, a sealant was applied to the periphery of the organic material formed on the glass substrate, and the The glass substrate and the glass substrate for sealing were bonded together, and ultraviolet light with a wavelength of 365 nm was applied for 6 hours. J / cm 2 The light-emitting element 1 was obtained by the above steps.

[0399] <Fabrication of Light-Emitting Elements 2 to 4 and Comparative Light-Emitting Element 5> The light-emitting elements 2 to 4 and the comparative light-emitting element 5 are the same as the light-emitting element 1 described above, except that the light-emitting layer 130 The only difference was the structure of the light-emitting element 1, and the other steps were the same as those for the light-emitting element 1. The details of the fabrication method are omitted here because they are as shown in Tables 1 and 2. In the optical element 4, the material used for the light-emitting layer 130 is the same for all light-emitting elements. The comparative light-emitting element 5 contains a fluorescent material having a protecting group. 2TMS-mmtBuDPhA2Anth is used, but it is a phosphorescent material Ir(dmdppr-dmp)2(dpm) is not used.

[0400] <Light-emitting element characteristics> Next, the characteristics of the fabricated light-emitting elements 1 to 4 and the comparative light-emitting element 5 were measured. The luminance and CIE chromaticity were measured using a color luminance meter (Topcon, BM-5A). The emission spectrum was measured using a multi-channel spectrometer (Hamamatsu Photonics, PMA-11 ) was used.

[0401] FIG. 14 shows the external quantum efficiency-luminance characteristics of the light-emitting elements 1 to 4 and the comparative light-emitting element 5. Furthermore, the light-emitting elements 1 to 4 and the comparative light-emitting element 5 each had a current density of 2.5 mA / cm 2 The electroluminescence spectra when a current was applied at a current density of 1000 sq. m / s are shown in FIG. The measurement of the light-emitting device was carried out at room temperature (an atmosphere maintained at 23°C). The toluene solution of 2TMS-mmtBuDPhA2Anth used in light-emitting elements 1 to 4 Absorption spectrum, emission spectrum, and dichloromethane of Ir(dmdppr-dmp)2(dpm) The absorption spectrum in fluoromethane solution and the EL spectrum of the comparative light-emitting element 9 (described later) (4, 6 The EL spectrum of the exciplex formed by mCzP2Pm and Ir(ppz)3 is shown.

[0402] The absorption spectrum of 2TMS-mmtBuDPhA2Anth in toluene and I Measurement of the absorption spectrum of r(dmdppr-dmp)2(dpm) in dichloromethane solution For the measurement, an ultraviolet-visible spectrophotometer (V550 model, manufactured by JASCO Corporation) was used. The absorption spectrum was measured using a toluene solution of 2TMS-mmtBuDPhA2Anth and Ir( Each spectrum of the absorption spectrum of (dmdppr-dmp)2(dpm) in dichloromethane solution The spectra obtained by subtracting the spectra measured with only the solvent in the quartz cell from the spectra obtained by the The emission spectrum was measured using a fluorometer (FS manufactured by Hamamatsu Photonics Co., Ltd.). 920) was used.

[0403] Also, 1000cd / m 2 Light-emitting elements 1 to 4 and comparative light-emitting elements in the vicinity The device characteristics of 5 are shown in Table 3.

[0404] [Table 3]

[0405] As shown in FIG. 15, the emission spectra of the light-emitting elements 1 to 4 are It was found that there were two peaks around 610 nm and 530 nm. The peak at around 610 nm is due to Ir(d That is, in the light-emitting elements 1 to 4, The emission from 2TMS-mmtBuDPhA2Anth and Ir(dmdppr- It was found that both luminescence from dmp2 (dpm) and dpm were obtained. Light-emitting element 5 emitted green light with a peak wavelength of 534 nm and a half-value width of 65 nm. Comparative light-emitting element 5 emits light derived from 2TMS-mmtBuDPhA2Anth. I found out that...

[0406] As shown in FIG. 14, the light-emitting elements 1 to 4 and the comparative light-emitting element 5 are made of fluorescent materials. Although the light emitted is derived from the material, the external quantum efficiency is high, exceeding 20%. Here, the recombination of carriers (holes and electrons) injected from a pair of electrodes The probability of generating singlet excitons is up to 25%, which increases the light extraction efficiency. is set to 25%, the external quantum efficiency of a typical fluorescent light-emitting device is 6.25% at most. In addition, for example, when the fluorescent material and the phosphorescent material emit light in a ratio of 1:1, The quantum efficiency was 15.5%. In some cases, only singlet excitons contribute to the emission, and in other cases, both fluorescent and phosphorescent materials contribute to the emission. This is because the electrons injected from the pair of electrodes are highly efficient compared to the electrons injected from the pair of electrodes. In addition to the emission from singlet excitons generated by the recombination of carriers (holes and electrons), , emission from triplet excitons, or reverse intersystem crossing in exciplexes This is because luminescence derived from singlet excitons generated from triplet excitons is obtained due to the difference. Therefore, in a light-emitting device using a fluorescent material having a protective group, non-radiative deactivation of triplet excitons is suppressed, and it can be said that both singlet excitation energy and triplet excitation energy are efficiently converted into luminescence. Note that Light-emitting devices 1 to 4 and Comparative light-emitting device 5 can be said to be light-emitting devices using ExEF.

[0407] Also, from FIGS. 14 and 15, Light-emitting devices 1 to 4 having both a phosphorescent material and a fluorescent material as materials that exhibit luminescence, and Comparative light-emitting device 5 having only a fluorescent material as a material that exhibits luminescence have equivalent efficiencies. That is, by using a fluorescent material having a protective group in the luminescent group, it was found that a light-emitting device having high luminous efficiency can be manufactured even when using both a phosphorescent material and a fluorescent material as materials that exhibit luminescence. Also, Comparative light-emitting device 5 can be regarded as a light-emitting device in which the concentration of the phosphorescent material is 0. Therefore, by adjusting either one or both of the concentration of the fluorescent material having a protective group and the concentration of the phosphorescent material contributing to luminescence, the emission color can be adjusted while maintaining high luminous efficiency. At this time, it is preferable that the concentration of the fluorescent material having a protective group is higher than the concentration of the phosphorescent material because luminescence of the fluorescent material and luminescence of the phosphorescent material can be obtained in good balance.

[0408] <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).

[0409] 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.

[0410] The CV measurement showed that the oxidation potential of 4,6mCzP2Pm was 0.95 V and the reduction potential was -2.0 6V. The HOMO level of 4,6mCzP2Pm calculated from CV measurements 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.

[0411] 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 r(ppz)3 can form an exciplex. The exciplex formed by P2Pm and Ir(ppz)3 has an emission peak around 530 nm. Has.

[0412] In addition, from Figure 16, the exciplex formed by 4,6mCzP2Pm and Ir(ppz)3 The obtained emission spectrum is the absorption spectrum of 2TMS-mmtBuDPhA2Anth and The absorption spectra overlap with those of both Ir(dmdppr-dmp)2(dpm) and Ir(dmdppr-dmp)2(dpm). Therefore, the excitation energy of the exciplex is efficiently converted to 2TMS-mmtBuDPhA Energy transfer to 2Anth and Ir(dmdppr-dmp)2(dpm) The emission spectrum of 2TMS-mmtBuDPhA2Anth is similar to that of Ir(dm The absorption spectrum of 2TMS overlaps with that of 2TMS (dppr-dmp)2 (dpm). -mmtBuDPhA2Anth to Ir(dmdppr-dmp)2(dpm) Therefore, according to one embodiment of the present invention, multicolor light emission with high luminous efficiency can be achieved. The device can be fabricated. [Example]

[0413] In this example, a light-emitting element according to one embodiment of the present invention and a comparative light-emitting element different from those in the previous examples were fabricated. The structure of the light-emitting element manufactured in this example is the same as that shown in FIG. The details of the device structure are shown in Tables 4 and 5. The structures and abbreviations of the compounds used are also shown in The following are examples of other organic compounds. stomach.

[0414] [ka]

[0415] [Table 4]

[0416] [Table 5]

[0417] <Fabrication of Light-Emitting Element 4, Light-Emitting Element 6, and Comparative Light-Emitting Elements 7 to 9> The element structure of the light-emitting element 4 is as shown in Example 1 and Table 3. Similarly, the light-emitting elements 6 and The manufacturing process of the comparative light-emitting elements 7 to 9 was the same as the manufacturing process of the light-emitting element 1 described above. Only the process for fabricating the layer 130 was different, and the other processes were the same as those for the light-emitting element 1. The details of the device structure are as shown in Table 3, and therefore the details of the fabrication method are omitted here. Light-emitting element 7 and comparative light-emitting element 8 are light-emitting elements using MeDPhA2A, a fluorescent material that does not have a protecting group. The comparative light-emitting element 9 is a light-emitting element that does not contain a fluorescent material.

[0418] <Light-emitting element characteristics> Next, the light-emitting element 4, the light-emitting element 6, and the comparative light-emitting elements 7 to 9 fabricated above were The device characteristics were measured using the same method as in Example 1.

[0419] External quantum efficiency and luminance of the light-emitting element 4, the light-emitting element 6, and the comparative light-emitting elements 7 to 9 The characteristics are shown in FIG. 17. 2.5mA / cm 2 Electroluminescence spectrum when a current is applied at a current density of The results are shown in Figure 18. The measurements of each light-emitting device were carried out at room temperature (in an atmosphere maintained at 23°C).

[0420] Also, 1000cd / m 2 Light-emitting element 4, light-emitting element 6, and comparative light-emitting element 7 in the vicinity Table 6 shows the element characteristics of the comparative light-emitting elements 1 to 9.

[0421] [Table 6]

[0422] As shown in FIG. 18, the emission spectra of the light-emitting elements 4 and 6 are It was found that there were two peaks around 530 nm and 610 nm. The peak at around 610 nm is due to Ir(dm That is, the light-emitting elements 4 and 6 are derived from The emission from 2TMS-mmtBuDPhA2Anth and Ir(dmdppr-dm p)2(dpm) and the luminescence from both were obtained. The light-emitting element 7 and the comparative light-emitting element 8 have two peaks near 530 nm and 610 nm. The peak at around 530 nm was due to MeDPhA2A, and the peak at around 610 nm was due to The peak near the center is due to Ir(dmdppr-dmp)2(dpm). The light-emitting element 7 and the comparative light-emitting element 8 are composed of light emitted from MeDPhA2A and Ir(dmdpp It was found that both luminescence originating from r-dmp2(dpm)2(dpm) were obtained. Comparative light-emitting element 9 emitted green light with a peak wavelength of 531 nm and a half-value width of 88 nm. Comparative light-emitting element 9 is an exciplex formed by 4,6mCzP2Pm and Ir(ppz)3. It was found that the luminescence derived from

[0423] As shown in FIG. 17, the light-emitting elements 4 and 6 emit light originating from fluorescent materials. Despite this, the external quantum efficiency was as high as or higher than that of Comparative Light-Emitting Device 9. Comparative light-emitting element 7 and comparative light-emitting element 8 exhibited significantly lower external quantum efficiency than comparative light-emitting element 9. The light-emitting element 4, the light-emitting element 6, the comparative light-emitting element 7, and the comparative light-emitting element 8 were compared with the comparative light-emitting element 9. They can be considered as elements to which fluorescent material and phosphorescent material are added, respectively. Although the light-emitting element 4 and the light-emitting element 6 contained the fluorescent material, the light-emitting element 4 and the light-emitting element 6 did not show the same results as the comparative light-emitting element 9. Multicolor light emission was obtained while maintaining the same luminous efficiency. In the comparative light-emitting element 8, the luminous efficiency was reduced by adding a fluorescent material and a phosphorescent material. The light-emitting element 4, the light-emitting element 6, the comparative light-emitting element 7, and the comparative light-emitting element 8 contain the same phosphorescent material. Therefore, the decrease in efficiency of the comparative light-emitting elements 7 and 8 is due to the fluorescent material. By using a fluorescent material without a protecting group, triplet excitons are quenched. On the other hand, in the light-emitting element of one embodiment of the present invention, triplet excitons It can be said that non-radiative deactivation is suppressed and efficiently converted into luminescence. By using a fluorescent material in the light-emitting layer, the fluorescent material can be obtained from the host material and the phosphorescent material. Dexter energy transfer of triplet excited energy to It was found that the non-radiative deactivation of energy can be suppressed.

[0424] Furthermore, the concentrations of the fluorescent material having a protecting group differ between the light-emitting element 4 and the light-emitting element 6. The comparative light-emitting element 7 and the comparative light-emitting element 8 have different concentrations of the fluorescent material that does not have a protecting group. From Table 4, the decrease rate of the external quantum efficiency between the light-emitting element 4 and the light-emitting element 6 (external quantum efficiency of the light-emitting element 4) The internal quantum efficiency of the light-emitting element 6 is expressed as (internal quantum efficiency - external quantum efficiency of the light-emitting element 6) / (external quantum efficiency of the light-emitting element 4)×100. The decrease in external quantum efficiency between the comparative light-emitting element 7 and the light-emitting element 8 was about 5%. (External quantum efficiency of comparative light-emitting element 7−External quantum efficiency of comparative light-emitting element 8) / Comparative light-emitting element 7 The external quantum efficiency (x100) is about 30%. By doing so, it can be seen that the decrease in efficiency due to an increase in the concentration of the fluorescent material is suppressed. .

[0425] <Changes in brightness of light-emitting elements> 19 shows the chromaticity-luminance characteristics of the light-emitting elements 4 and 6. The chromaticity x and chromaticity y of the light-emitting element 4 and the light-emitting element 6 hardly change depending on the luminance. That is, the light-emitting elements 4 and 6 exhibit very little color change due to changes in luminance. This is because the light-emitting elements 4 and 6 have stable emission colors. The fluorescent material and the phosphorescent material are connected by an energy transfer of excitation energy from the energy donor. This is because the light is emitted through a change in brightness. It is clear that a light-emitting device that emits multicolor light with little color change due to light irradiation can be fabricated.

[0426] <Light-emitting element reliability test> Next, for the light-emitting element 6, the comparative light-emitting element 5, and the comparative light-emitting element 9, the constant current at 2 mA was measured. A current drive test was carried out, and the results are shown in Figure 20. From Figure 20, it can be seen that the fluorescent material and the phosphorescent material The driving life of the comparative light-emitting element 5 having a fluorescent material is compared with the driving life of the comparative light-emitting element 9 having no fluorescent material. The lifetime is good, and the light-emitting element 6 having both fluorescent and phosphorescent materials has even better driving characteristics. That is, according to one embodiment of the present invention, a highly reliable luminous efficiency can be obtained. A light-emitting device that exhibits excellent multicolor emission can be fabricated.

[0427] Next, a reliability test was carried out to measure the electroluminescence of the light-emitting element 6 after the luminance had decreased to 50%. and 2.5 mA / cm for Light-emitting element 6 before the reliability test. 2 Electric field generation in The optical spectrum is shown in Figure 21. The spectral intensity shown in Figure 21 is As can be seen from FIG. 21, the light-emitting element 6 has a higher field emission efficiency than the light-emitting element 6 before and after the reliability test. It can be seen that the shape of the optical spectrum hardly changes. The fluorescent material and the phosphorescent material are connected by the energy transfer of excitation energy from the energy donor. Therefore, according to one embodiment of the present invention, It is clear that a light-emitting device that emits multicolor light with little color change before and after irradiation can be fabricated. [Example]

[0428] In this example, a light-emitting element according to one embodiment of the present invention and a comparative light-emitting element different from those in the previous examples were fabricated. The structure of the light-emitting element manufactured in this example is the same as that shown in FIG. The details of the device structure are shown in Table 7. The structures and abbreviations of the compounds used are shown below. For other organic compounds, the above examples and embodiments may be referred to.

[0429] [ka]

[0430] [Table 7]

[0431] <Fabrication of Light-Emitting Element 10, Comparative Light-Emitting Element 11, and Comparative Light-Emitting Element 12> The light-emitting element 10, the comparative light-emitting element 11, and the comparative light-emitting element 12 were fabricated in the same manner as the light-emitting element described above. The manufacturing process of the device 1 differs from that of the device 1 only in the manufacturing process of the hole transport layer 112 and the light-emitting layer 130. The fabrication process was the same as that of Light-emitting element 1. The details of the element structure are shown in Table 7. The details of the manufacturing method will be omitted. As will be described later in detail, the light emitting device 10 emits fluorescent material having a protecting group. The photosensitive material, 1,3,8,10-tetra-tert-butyl-7,14-bis(3, 5-Di-tert-butylphenyl)-5,12-dihydroquino[2,3-b]acridi Oct-tBuDPQd and the phosphorescent material Ir(d The emission of mdppr-dm)2(dpm) is obtained.

[0432] The light-emitting element 10 is considered to be a light-emitting element obtained by adding a phosphorescent material to the comparative light-emitting element 11. The comparative light-emitting element 11 can be made of a fluorescent material having a protecting group. Therefore, the light-emitting element 10 can be considered as a light-emitting element to which the comparative light-emitting element 12 is added. It can be considered a device to which fluorescent and phosphorescent materials having protecting groups are added.

[0433] <Light-emitting element characteristics> Next, the device characteristics of the light-emitting element 10, the comparative light-emitting element 11, and the comparative light-emitting element 12 fabricated above were The measurement method was the same as in Example 1.

[0434] FIG. 1 shows the external quantum efficiency-luminance characteristics of the light-emitting element 10, the comparative light-emitting element 11, and the comparative light-emitting element 12. 26. In addition, the light-emitting element 10, the comparative light-emitting element 11, and the comparative light-emitting element 12 each have a 2.5mA / cm 2 FIG. 27 shows the electroluminescence spectrum when a current was passed at a current density of . The measurements of each light-emitting device were carried out at room temperature (in an atmosphere maintained at 23°C).

[0435] Also, 1000cd / m 2 The light-emitting element 10, the comparative light-emitting element 11, and the comparative light-emitting element 12 are The device characteristics of the optical device 12 are shown in Table 8.

[0436] [Table 8]

[0437] As shown in FIG. 27, the emission spectrum of the light-emitting element 10 is The peak at 526 nm is due to Oct-tBu. The peak at around 608 nm is due to Ir(dmdppr-dmp)2(dpm That is, the light-emitting element 10 emits light derived from Oct-tBuDPQd and Both the emission from Ir(dmdppr-dmp)2(dpm) and the emission from It was also found that the comparative light-emitting element 11 had a peak at a wavelength of around 526 nm. The peak near 526 nm is due to Oct-tBuDPQd. The emission spectrum of 12 has a peak at around 506 nm and a half-width of 81 nm. The light emitted from the comparative light-emitting element 12 was derived from 3Cz2DPhCzBN. Non-Patent Document 1 describes that PhCzBN is a TADF material.

[0438] As shown in FIG. 26, the light-emitting element 10 emits light originating from a fluorescent material. Regardless of the above, the light-emitting element 1 exhibited a high external quantum efficiency equal to or higher than that of the comparative light-emitting element 12. 0 shows a higher external quantum efficiency than the comparative light-emitting element 11. Light emission from both the photoluminescent material and the phosphorescent material can be obtained, and Comparative Light-Emitting Element 11 and Comparative Light-Emitting Element 1 As described above, this is because the light-emitting element according to one embodiment of the present invention has a higher luminous efficiency than that of the light-emitting element according to one embodiment of the present invention. This can be attributed to the fact that non-radiative deactivation of triplet excitons is suppressed and they are efficiently converted into light emission.

[0439] Furthermore, the light-emitting element 10 uses a TADF material as an energy donor. A TADF material can be suitably used for the light-emitting element of one embodiment of the present invention. In 10, we developed an organic compound having a quinacridone skeleton as a fluorescent material with a protecting group. Therefore, the light-emitting element of one embodiment of the present invention uses an organic compound having a quinacridone skeleton. The compound can be suitably used. [Example]

[0440] In this example, a light-emitting element according to one embodiment of the present invention and a comparative light-emitting element different from those in the previous examples were fabricated. The structure of the light-emitting element manufactured in this example is the same as that shown in FIG. The details of the device structure are shown in Table 7. The structures and abbreviations of the compounds used are shown below. For other organic compounds, the above examples and embodiments may be referred to.

[0441] [ka]

[0442] [Table 9]

[0443] <Fabrication of Light-Emitting Element 13> The manufacturing process of the light emitting element 13 is the same as the manufacturing process of the light emitting element 10 and the manufacturing process of the light emitting layer 130. The only difference was the manufacturing process, and the other steps were the same as those for the light-emitting element 10. The details of the preparation method are omitted here, as they are shown in Table 9.

[0444] <Light-emitting element characteristics> Next, the device characteristics of the fabricated light-emitting device 13 were measured. The measurement method was the same as in Example 1. The same is true.

[0445] The external quantum efficiency vs. luminance characteristics of the light-emitting element 13 are shown in FIG. mA / cm 2 The electroluminescence spectrum when a current was passed at a current density of The light-emitting device was measured at room temperature (in an atmosphere maintained at 23°C).

[0446] Also, 3cd / m 2 The device characteristics of the light-emitting element 13 in the vicinity are shown in Table 10.

[0447] [Table 10]

[0448] As shown in FIG. 29, the emission spectrum of the light-emitting element 13 is The peak at 527 nm is due to Oct-tBu. The peak at around 567 nm is due to DPQd, and the peak at around 567 nm is due to the TADF material 7,10-Bis(4 -(diphenylamino)phenyl)-2,3-dicyanopyraz It is derived from ino phenanthrene (abbreviation: TPA-DCPP). The light-emitting device 13 emits light from Oct-tBuDPQd and TPA-DCPP. It was found that both the above-mentioned luminescence and the above-mentioned luminescence were obtained. Non-patent document 2 describes this.

[0449] As shown in FIG. 28, the light-emitting element 13 emits light originating from a fluorescent material. Regardless, a high external quantum efficiency exceeding the theoretical efficiency of a conventional fluorescent element was obtained.

[0450] (Reference example 1) In this reference example, 2TMS, which is a fluorescent material having a protecting group used in Examples 1 and 2, The synthesis method of -mmtBuDPhA2Anth {structural formula (229)} will be explained.

[0451] <Step 1: Synthesis of 9,10-dibromo-2-trimethylsilyl anthracene> 2.7 g (11 mmol) of 2-trimethylsilyl anthracene was placed in a 500 mL three-neck flask. The flask was then purged with nitrogen. The mixture was stirred at room temperature. After stirring, water was added to the reaction mixture to separate the aqueous layer and the organic layer. The aqueous layer was extracted with toluene, and the resulting extract and organic layer were combined. The mixed solution was washed with water and saturated aqueous sodium thiosulfate solution, and then dried over magnesium sulfate. This mixture was separated by gravity filtration, and the filtrate was concentrated to obtain a yellow-brown solid. 450 mL of hexane and 50 mL of toluene were added to the colored solid, and then the solid was dissolved in Florisil (Wako Pure Chemical Industries, Ltd.). Industrial Co., Ltd., Catalog No.: 066-05265), Celite (Wako Pure Chemical Industries, Ltd. , Catalog No.: 537-02305), and suction-filter the filtrate through aluminum oxide. The obtained filtrate was concentrated to give a yellow-brown solid. The obtained solid was extracted with ethyl acetate / ethanol. The compound was recrystallized in ethanol to give 2.4 g of a yellow solid in a yield of 54%. Shown below in (F-1).

[0452] [ka]

[0453] 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 22 and 23. Note that Figure 22(B) is the same as Figure 22 This is a chart showing an enlarged range of 6.5 ppm to 9.0 ppm in (A). FIG. 23 is an enlarged view of the range from 0.0 ppm to 2.0 ppm in FIG. 22(A). This chart shows the results of 9,10-dibromo-2-trimethylsilyl It was found that thracene was obtained.

[0454] 1 H NMR (CDCl3,300MHz):σ=8.74(s, 1H), 8.63-8 .56(m, 2H), 8.55(d, J=8.8Hz, 1H), 7.75(d, J=8. 3Hz, 1H), 7.68-7.61(m, 2H), 0.42(s, 9H).

[0455] <Step 2: Synthesis of 2TMS-mmtBuDPhA2Anth> 1.4 g (3.3 mmol) of 9,10-dibromo-2-trimethylsilyl anthracene and 2.6 g (6.6 mmol) of bis(3,5-tert-butylphenyl)amine. , 1.3 g (14 mmol) of sodium t-butoxide and 60 mg (0.15 mm ol) 2-dicyclohexylphosphino-2',6'-dimethoxy-1,1'-biphene The contents of the flask were replaced with nitrogen. 33 mL of xylene was added to the mixture, and the mixture was degassed under reduced pressure. mg (70 μmol) of bis(dibenzylideneacetone)palladium(0) was added, and The mixture was stirred at 150°C for 6 hours under a nitrogen atmosphere. After stirring, 4 toluene Add 00 mL of the solution and then filter through Florisil, Celite, and aluminum oxide. The filtrate was concentrated to give a brown solid. This solid was purified by silica gel column chromatography. When purified by chromatography (developing solvent: hexane:toluene 9:1), a yellow The yellow solid was recrystallized with ethyl acetate and ethanol to obtain the target compound. 0.40 g of a yellow solid was obtained in a yield of 12%. The synthesis scheme for Step 2 is shown below (F-2 ) shown.

[0456] [ka]

[0457] 0.40 g of the resulting yellow solid was purified by train sublimation. The purification was carried out by heating the yellow solid at 260°C for 15 hours under a pressure of 3.5 Pa. After the purification, the target yellow solid was obtained in a yield of 0.35 g and a recovery rate of 87%.

[0458] 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 24 and 25. Note that Figure 24(B) is the same as Figure 24( A) is a chart showing an enlarged range from 6.5 ppm to 9.0 ppm. FIG. 25 shows an enlarged view of the range from 0.0 ppm to 2.0 ppm in FIG. 24(A). From this result, 2TMS-mmtBuDPhA2Anth was obtained. I found out that...

[0459] 1 H NMR (CDCl3,300MHz):σ=8.25(s, 1H), 8.24-8 .21(m, 1H), 8.15-8.11(m, 2H), 7.40-7.37(m, 1H) ), 7.30-7.27(m, 2H), 6.97-6.94(m, 8H), 6.92-6 .91(m, 4H), 1.14(s, 36H), 1.12(m, 36H), 0.09(s , 9H).

[0460] (Reference example 2) In this reference example, the fluorescent material having a protecting group, Oct- The synthesis method of tBuDPQd {structural formula (104)} will be explained.

[0461] <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).

[0462] [ka]

[0463] 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

[0464] 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).

[0465] 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).

[0466] [ka]

[0467] 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

[0468] 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).

[0469] 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).

[0470] [ka]

[0471] 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

[0472] 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).

[0473] 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 of hexane and 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).

[0474] [ka]

[0475] In addition, the yellow solid obtained in step 4 above 1 The results of the H NMR measurements are shown below. Also, 1The H NMR charts are shown in Figures 30 and 31. Note that Figure 30(B) is the same as Figure 30 This is a chart showing an enlarged range of 6.5 ppm to 9.0 ppm in (A). FIG. 31 shows an enlarged view of the range from 0.5 ppm to 2.0 ppm in FIG. 30(A). This chart shows that Oct-tBuDPQd was obtained. Ta.

[0476] 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). [Explanation of symbols]

[0477] 100 EL layer 101 Electrode 102 electrode 106 Lighting Unit 108 Lighting Unit 111 Hole injection layer 112 Hole transport layer 113 Electron transport layer 114 Electron injection layer 115 Charge generation layer 116 Hole injection layer 117 Hole transport layer 118 Electron transport layer 119 Electron injection layer 120 luminescent layer 130 Light-emitting layer 131 compounds 132 compounds 133 Compound 135 Compound 136 compounds 150 light-emitting elements 170 Light-emitting layer 250 light-emitting elements 301 Guest Materials 302 Guest Materials 310 Luminous Group 320 Protecting Group 330 Host Material 601 Source side drive circuit 602 Pixel section 603 Gate side drive circuit 604 Sealing substrate 605 Sealing material 607 Space 608 Wiring 609 FPC 610 Element substrate 611 Switching TFT 612 Current Control TFT 613 Electrode 614 Insulators 616 EL layer 617 Electrode 618 Light-emitting element 623 n-channel TFT 624 p-channel TFT 625 Dry material 900 Mobile Information Terminals 901 Case 902 Case 903 Display section 905 Hinge part 910 Mobile Information Terminal 911 chassis 912 Display section 913 Operation button 914 External connection port 915 Speaker 916 Mike 917 Camera 920 Camera 921 Case 922 Display section 923 Operation Button 924 shutter button 926 Lens 1001 board 1002 Undercoat insulating film 1003 Gate insulating film 1006 Gate electrode 1007 Gate electrode 1008 gate electrode 1020 Interlayer insulating film 1021 Interlayer insulating film 1022 Electrode 1024B Electrode 1024G electrode 1024R electrode 1024W electrode 1025B Lower electrode 1025G bottom electrode 1025R lower electrode 1025W bottom electrode 1026 Bulkhead 1028 EL layer 1029 Electrode 1031 Sealing substrate 1032 Sealing material 1033 Base material 1034B Colored layer 1034G colored layer 1034R colored layer 1036 Overcoat layer 1037 Interlayer insulating film 1040 pixel section 1041 Drive circuit section 1042 Periphery 2100 Robot 2101 Illuminance sensor 2102 Microphone 2103 Upper Camera 2104 Speaker 2105 Display 2106 Lower Camera 2107 Obstacle Sensor 2108 Moving mechanism 2110 Arithmetic equipment 5000 cabinets 5001 Display section 5002 Display section 5003 Speaker 5004 LED lamp 5005 Operation key 5006 Connection terminal 5007 Sensor 5008 Microphone 5012 Support part 5013 Earphones 5100 Cleaning Robot 5101 Display 5102 Camera 5103 Brush 5104 Operation button 5120 Garbage 5140 Portable electronic devices 5150 Personal Digital Assistant 5151 Case 5152 Display area 5153 Bend 8501 Lighting equipment 8502 Lighting equipment 8503 Lighting equipment 8504 Lighting equipment

Claims

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, a second material having a function of converting singlet excitation energy into luminescence, and a third material having a function of converting triplet excitation energy into luminescence; the first material includes a first organic compound and a second organic compound; the first organic compound and the second organic compound are a combination that forms an exciplex, the first organic compound is a compound having TADF properties, 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 comprise 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 both the second material and the third material.

2. In claim 1, a light-emitting element, wherein at least four of the five or more protecting groups are each independently any one of an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a trialkylsilyl group having 3 to 12 carbon atoms.

3. 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, a second material having a function of converting singlet excitation energy into luminescence, and a third material having a function of converting triplet excitation energy into luminescence; the first material includes a first organic compound and a second organic compound; the first organic compound and the second organic compound are a combination that forms an exciplex, the first organic compound is a compound having TADF properties, the second material has a luminophore and four protecting groups; the luminophore is a fused aromatic ring or a fused heteroaromatic ring; the four protecting groups are not directly bonded to the fused aromatic ring or to the fused aromatic ring; the four protecting groups each independently include one of an alkyl group having from 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having from 3 to 10 carbon atoms, and a trialkylsilyl group having from 3 to 12 carbon atoms; A light-emitting element in which light is emitted from both the second material and the third material.

4. 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, a second material having a function of converting singlet excitation energy into luminescence, and a third material having a function of converting triplet excitation energy into luminescence; the first material includes a first organic compound and a second organic compound; the first organic compound and the second organic compound are a combination that forms an exciplex, the first organic compound is a compound having TADF properties, the second material comprises a luminophore and two or more diarylamino groups; the luminophore is a fused aromatic ring or a fused heteroaromatic ring; the fused aromatic ring or the fused heteroaromatic ring is bonded to the two or more diarylamino groups; each aryl group in the two or more diarylamino groups independently has at least one protecting group; the protecting groups each independently have one of an alkyl group having from 3 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 both the second material and the third material.

5. 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, a second material having a function of converting singlet excitation energy into luminescence, and a third material having a function of converting triplet excitation energy into luminescence; the first material includes a first organic compound and a second organic compound; the first organic compound and the second organic compound are a combination that forms an exciplex, the first organic compound is a compound having TADF properties, the second material comprises a luminophore and two or more diarylamino groups; the luminophore is a fused aromatic ring or a fused heteroaromatic ring; the fused aromatic ring or the fused heteroaromatic ring is bonded to the two or more diarylamino groups; each aryl group in the two or more diarylamino groups independently has at least two protecting groups; the protecting groups each independently have one of an alkyl group having from 3 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 both the second material and the third material.

6. In claim 4 or claim 5, The light-emitting device wherein the diarylamino group is a diphenylamino group.

7. In any one of claims 2 to 6, The alkyl group having 3 to 10 carbon atoms is a branched alkyl group.

8. 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, a second material having a function of converting singlet excitation energy into luminescence, and a third material having a function of converting triplet excitation energy into luminescence; the first material includes a first organic compound and a second organic compound; the first organic compound and the second organic compound are a combination that forms an exciplex, the first organic compound is a compound having TADF properties, the second material comprises a luminophore and a plurality of protecting groups; the luminophore is a fused aromatic ring or a fused heteroaromatic ring; at least one of the atoms constituting the plurality of protecting groups is located immediately above one face of the fused aromatic ring or the fused heteroaromatic ring, and at least one of the atoms constituting the plurality of protecting groups is located immediately above the other face of the fused aromatic ring or the fused heteroaromatic ring; A light-emitting element in which light is emitted from both the second material and the third material.

9. 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, a second material having a function of converting singlet excitation energy into luminescence, and a third material having a function of converting triplet excitation energy into luminescence; the first material includes a first organic compound and a second organic compound; the first organic compound and the second organic compound are a combination that forms an exciplex, the first organic compound is a compound having TADF properties, the second material comprises a luminophore and two or more diphenylamino groups; the luminophore is a fused aromatic ring or a fused heteroaromatic ring; the fused aromatic ring or the fused heteroaromatic ring is bonded to the two or more diphenylamino groups; the phenyl groups in the two or more diphenylamino groups each independently have protecting groups at the 3- and 5-positions, the protecting groups each independently have one of an alkyl group having from 3 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 both the second material and the third material.

10. In claim 9, The alkyl group having 3 to 10 carbon atoms is a branched alkyl group.

11. In claim 7 or claim 10, The branched alkyl group has a quaternary carbon atom.

12. In any one of claims 1 to 11, The light-emitting device, wherein the fused aromatic ring or the fused heteroaromatic ring contains any one of naphthalene, anthracene, fluorene, chrysene, triphenylene, tetracene, pyrene, perylene, coumarin, quinacridone, and naphthobisbenzofuran.

13. In any one of claims 1 to 12, A light-emitting element, wherein the peak wavelength of the emission spectrum of the first material is positioned on the shorter wavelength side than the peak wavelength of the emission spectrum of the second material.

14. In any one of claims 1 to 13, A light-emitting device, wherein the emission spectrum of the first material overlaps with the longest wavelength absorption band of the absorption spectrum of the second material.

15. In any one of claims 1 to 14, A light-emitting element, wherein the concentration of the second material is higher than the concentration of the third material in the light-emitting layer.

16. In any one of claims 1 to 15, The light-emitting element, wherein the third material is a compound that exhibits phosphorescence.

17. In any one of claims 1 to 16, A light-emitting element, wherein the peak wavelength of the emission spectrum of the second material is positioned on the shorter wavelength side than the peak wavelength of the emission spectrum of the third material.

18. A light-emitting element according to any one of claims 1 to 17; and at least one of a color filter and a transistor.

19. A light emitting device according to claim 18; An electronic device having at least one of a housing or a display unit.

20. A light-emitting element according to any one of claims 1 to 17; A lighting device having a housing.

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