Light-emitting device, electronic apparatus and luminaire

Abstract

To provide a light-emitting device where the light emission efficiency and the reliability are high.SOLUTION: A light-emitting device contains a host material and a guest material in a light-emitting layer. The host material has a function for converting triplet excitation energy into light emission, and the guest material emits fluorescent light. A molecular structure of the guest material is a structure having a luminophore and protective groups. Five or protective groups are included in one molecule of the guest material. The protective groups are led into the molecule, thereby suppressing triplet excitation energy transfer, caused by a Dexter mechanism, from the host material to the guest material. As the protective groups, an alkyl group and a branched-chain alkyl group are used. A material having a 5-membered ring skeleton is used for the host material, thereby obtaining the light-emitting device where the light emission efficiency is further improved.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] One embodiment of the present invention is a light-emitting device, or a display device or an electronic device including the light-emitting device. 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 the present 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, and a power storage device. Examples of the memory device include a memory device, a method for driving the memory device, or a method for manufacturing the memory device. Cut. [Background technology]

[0003] In recent years, electroluminescence (EL) The research and development of light-emitting devices that utilize these materials is being actively carried out. The typical structure is a layer containing a light-emitting substance (EL layer) sandwiched between a pair of electrodes. By applying a voltage between the electrodes of the device, light can be emitted from the luminescent material.

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

[0005] An EL device that uses an organic compound as a light-emitting substance and has the light-emitting organic compound between a pair of electrodes In the case of a light-emitting device with layers (e.g., an organic electroluminescence (EL) device), a voltage is applied between a pair of electrodes. By applying a voltage to the cathode, electrons and holes are emitted from the anode, forming an EL layer that emits light. Then, the injected electrons and holes recombine, causing a current to flow. The light-emitting organic compound is excited, and light is emitted from the excited light-emitting organic compound. This can be done.

[0006] The types of excited states that organic compounds can form include singlet excited states (S * ) and triplet excitation Status(T * ) in which the emission from the singlet excited state is fluorescent and the emission from the triplet excited state is phosphorescent. The statistical rate of their generation in a light-emitting device is S * :T * =1:3. Therefore, light-emitting devices using compounds that emit fluorescence (fluorescent materials) Light-emitting devices using compounds that emit phosphorescence (phosphorescent materials) have higher luminous efficiency than Therefore, it is possible to convert the energy of the triplet excited state into light emission. In recent years, there has been active development of light-emitting devices using phosphorescent materials that are capable of emitting light.

[0007] Among light-emitting devices using phosphorescent materials, particularly light-emitting devices that emit blue light, However, it is difficult to develop stable compounds with high triplet excitation energy levels. Therefore, the development of light-emitting devices using more stable fluorescent materials is being pursued. Research is currently being conducted to improve the luminous efficiency of light-emitting devices using fluorescent materials (fluorescent light-emitting devices). Methods to achieve this are being explored.

[0008] As a material capable of converting part or all of the energy of the triplet excited state into light emission, In addition to phosphorescent materials, thermally activated delayed fluorescence (TFA) materials are also used. Thermally activated delayed fluorescence (TADF) materials are known. In delayed fluorescent materials, the singlet excited state is generated from the triplet excited state by reverse intersystem crossing. , which is converted from the singlet excited state to emit light.

[0009] In order to increase the luminous efficiency of a light-emitting device using a thermally activated delayed fluorescent material, In thermally activated delayed fluorescent materials, the singlet excited state is efficiently generated from the triplet excited state. Not only that, but also that emission from the singlet excited state can be obtained efficiently, i.e., the fluorescence quantum yield However, it is difficult to design a light-emitting material that satisfies both of these requirements at the same time. It is difficult to do so.

[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 the A method for obtaining light emission from thermally activated delayed fluorescence has been proposed (see Patent Document 1). A light-emitting device using a material as a host material and a fluorescent material as a guest material has been proposed. is. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] JP 2014-45179 A Summary of the Invention [Problem to be solved by the invention]

[0012] For example, the efficiency of fluorescent light-emitting devices can be improved by forming an emission layer having a host material and a guest material. After converting triplet excitation energy of the host material into singlet excitation energy, By transferring singlet excitation energy to the fluorescent guest material, a fluorescent device is generated. However, the triplet excitation of the host material is not sufficient to improve the luminescence efficiency of the device. The process in which the excited energy is converted into singlet excited energy is called the deactivation of triplet excited energy. Therefore, the triplet excitation energy of the host material is not sufficient to induce singlet excitation. In some cases, triplet excitation energy is not converted into energy. Examples of pathways for the deactivation of triplet excitation energy include For example, when a fluorescent material is used as a guest material in the light-emitting layer of a light-emitting device, the fluorescent The lowest triplet excited energy level (T1 level) of the photoactive material is the triplet excited energy level of the host material. A deactivation pathway through which excitation energy is transferred is considered. does not contribute to light emission, leading to a decrease in the luminous efficiency of fluorescent light-emitting devices. This can be suppressed by reducing the concentration of the guest material, but in that case, the host material The rate of energy transfer from the cation to the singlet excited state of the guest material is also slowed down. This makes the luminance of the light-emitting device more susceptible to quenching by impurities and other substances. This leads to a decrease in reliability.

[0013] In view of this, in one embodiment of the present invention, the host material and the guest material of the light-emitting layer of the light-emitting device are In this case, the triplet excitation energy of the host material is prevented from transferring to the T1 level of the guest material. By controlling the triplet excitation energy of the host material, the singlet excitation energy of the guest material can be efficiently converted This will increase the fluorescent efficiency of light-emitting devices and improve their reliability. The purpose is.

[0014] Another object of one embodiment of the present invention is to provide a light-emitting device with high emission efficiency. Another object of one embodiment of the present invention is to provide a highly reliable light-emitting device. Another object of one embodiment of the present invention is to provide a light-emitting device with reduced power consumption. Another object of one embodiment of the present invention is to provide a novel light-emitting device. An object of one embodiment of the present invention is to provide a novel light-emitting device. In one embodiment, an object of the present invention is to provide a novel display device.

[0015] 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]

[0016] In one embodiment of the present invention, a triplet excited electron of a host material in an emitting layer of a light-emitting device is In order to suppress the transfer of energy to the T1 level of the guest material, the host material ( Energy transfer between a guest material (energy acceptor) and a gated material (energy donor) We have proposed a light-emitting device that can mainly suppress energy transfer by the Dexter mechanism. Provide.

[0017] In order to suppress the energy transfer due to the Dexter mechanism, the energy The distance between the donor and the energy acceptor is set to a distance such that the energy transfer does not occur. Therefore, in one embodiment of the present invention, the energy donor and the energy In order to separate the acceptor from the luminophore to such a distance that the energy transfer does not occur, To achieve this, we used an energy donor with a bulky structure and an energy acceptor with a protecting group. In one embodiment of the present invention, a light-emitting device using the energy donor is provided. The triplet level (T1 level) of the energy acceptor is It is preferable that the level is higher than that of the other two.

[0018] In one embodiment of the present invention, a five-membered ring structure is used as the energy donor having a bulky structure. A material with a substituent at the center is used. A fluorescent material is used as the energy acceptor. However, the fluorescent material has a bulky structure due to the presence of a protecting group. The five-membered ring skeleton of the is particularly preferably an imidazole skeleton or a triazole skeleton. stomach.

[0019] Therefore, one aspect of the present invention is a light-emitting device having a light-emitting layer between a pair of electrodes, The layer has a first material and a second material, the first material converting triplet excitation energy into light emission. The second material is capable of converting singlet excitation energy into light emission. and having a luminophore and five or more protecting groups, the luminophore being a condensed aromatic ring or a condensed heteroaromatic ring. The five or more protecting groups are each independently an alkyl group having 1 to 10 carbon atoms, or unsubstituted cycloalkyl group having 3 to 10 carbon atoms; The first material has one of the alkylsilyl groups, and the T1 level of the first material is This is a light-emitting device with a higher S1 level than that of the conventional device.

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

[0021] Another embodiment of the present invention is a light-emitting device having a light-emitting layer between a pair of electrodes, The optical layer includes a first material and a second material, the first material converting triplet excitation energy into light emission. The second material has a five-membered ring structure and is capable of converting singlet excitation energy into light emission. and having a luminophore and at least four protecting groups, the luminophore being a fused aromatic or fused heterocyclic ring. The four protecting groups are not directly bonded to the condensed aromatic ring or condensed heteroaromatic ring, and the four Each of the protecting groups is independently an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted Cycloalkyl groups with 3 to 10 carbon atoms, and trialkylsilyl groups with 3 to 12 carbon atoms. The T1 level of the first material is higher than the S1 level of the second material. It is a highly efficient light-emitting device.

[0022] Another embodiment of the present invention is a light-emitting device having a light-emitting layer between a pair of electrodes, The optical layer includes a first material and a second material, the first material converting triplet excitation energy into light emission. The second material has a five-membered ring structure and is capable of converting singlet excitation energy into light emission. and having a luminophore and two or more diarylamino groups, the luminophore being a condensed aromatic ring or a condensed The aromatic heterocyclic ring is a condensed aromatic ring or a condensed heterocyclic aromatic ring bonded to two or more diarylamino groups. In combination, each of the aryl groups in the two or more diarylamino groups is independently at least one Each of the protecting groups is independently an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms; The T1 level of the first material is higher than that of the second material. This is a light-emitting device with a higher S1 level than the S1 level.

[0023] Another embodiment of the present invention is a light-emitting device having a light-emitting layer between a pair of electrodes, The optical layer includes a first material and a second material, the first material converting triplet excitation energy into light emission. The second material has a five-membered ring structure and is capable of converting singlet excitation energy into light emission. and having a luminophore and two or more diarylamino groups, the luminophore being a condensed aromatic ring or a condensed The aromatic heterocyclic ring is a condensed aromatic ring or a condensed heterocyclic aromatic ring bonded to two or more diarylamino groups. In combination, the aryl groups in the two or more diarylamino groups each independently represent at least two Each of the protecting groups is independently an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms; The T1 level of the first material is higher than that of the second material. This is a light-emitting device with a higher S1 level than the S1 level.

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

[0025] Another embodiment of the present invention is a light-emitting device having a light-emitting layer between a pair of electrodes, The optical layer includes a first material and a second material, the first material converting triplet excitation energy into light emission. The second material can be converted to a singlet excited state and has a five-membered ring structure. a compound that can be converted to light and has a luminophore and a plurality of protecting groups, each of the protecting groups being independently an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted alkyl group having 3 to 10 carbon atoms, a cycloalkyl group or a trialkylsilyl group having 3 to 12 carbon atoms; The luminophore is a condensed aromatic ring or a condensed heteroaromatic ring, and at least one of the atoms constituting the protecting group one of the protecting groups is located directly on one side of the fused aromatic ring or fused heteroaromatic ring, and At least one of the atoms constituting the fused ring or fused heteroaromatic ring is located directly above the other face of the fused ring or heteroaromatic ring. The T1 level of the first material is higher than the S1 level of the second material. It is.

[0026] Another embodiment of the present invention is a light-emitting device having a light-emitting layer between a pair of electrodes, The optical layer includes a first material and a second material, the first material converting triplet excitation energy into light emission. The second material has a five-membered ring structure and is capable of converting singlet excitation energy into light emission. and having a luminophore and two or more diphenylamino groups, the luminophore being a condensed aromatic ring or a condensed A heteroaromatic ring, the condensed aromatic ring or the condensed heteroaromatic ring is bonded to two or more diphenylamino groups. In combination, the phenyl groups in the two or more diphenylamino groups each independently correspond to the 3- and 5-positions. Each of the protecting groups is independently an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms; The T1 level of the first material is higher than that of the second material. This is a light-emitting device with a higher S1 level than the S1 level.

[0027] In the above structure, the five-membered ring skeleton is a pyrazole skeleton, an imidazole skeleton, a triazole skeleton, It is preferable that the compound has one of the following structures: an imidazole skeleton and a triazole skeleton. The nitrogen atoms not involved in the double bond are substituted or unsubstituted aromatic carbon atoms having 6 to 13 carbon atoms. It is more preferred that the alkyl group has a hydride group.

[0028] Another embodiment of the present invention is a light-emitting device having a light-emitting layer between a pair of electrodes, The optical layer includes a first material and a second material, the first material converting triplet excitation energy into light emission. The second material has a five-membered ring structure and is capable of converting singlet excitation energy into light emission. and having a luminophore and two or more protecting groups, the luminophore being a condensed aromatic ring or a condensed heteroaromatic ring. and the two or more protecting groups are each independently an alkyl group having 1 to 10 carbon atoms, or unsubstituted cycloalkyl group having 3 to 10 carbon atoms; The first material has a five-membered ring skeleton, and the second material has a five-membered ring skeleton. has at least one of an imidazole skeleton or a triazole skeleton, The nitrogen atoms not involved in the double bond of the azole skeleton and the triazole skeleton may be substituted or unsubstituted. The first material has a substituted aromatic hydrocarbon group having 6 to 13 carbon atoms, and the T1 level of the first material is This is a light-emitting device with a higher S1 level than that of the material.

[0029] In the above structure, the aromatic hydrocarbon group is preferably a phenyl group.

[0030] In the above structure, the alkyl group is preferably a branched chain alkyl group.

[0031] In the above structure, it is preferable that the branched alkyl group has a quaternary carbon.

[0032] In the above-mentioned structure, the condensed aromatic ring or the condensed heteroaromatic ring is preferably naphthalene, anthracene, fluorene, chrysene, triphenylene, pyrene, tetracene, perylene, coumarin It is preferable that the benzofuran compound contains any one of quinacridone and naphthobisbenzofuran.

[0033] In the above structure, the light-emitting layer further includes a third material, and the first material and the third material It is preferred that the compound form an exciplex.

[0034] In the above-mentioned structure, the emission spectrum of the exciplex overlaps with the absorption band on the longest wavelength side of the second material. It would be preferable.

[0035] In the above structure, the five-membered ring skeleton is a pyrazole skeleton, an imidazole skeleton, a triazole skeleton, It is preferable to have any one of the above cases.

[0036] In the above structure, the first material is preferably a metal complex. It has a metal of Groups 8 to 10 and Periods 5 and 6, and the five-membered ring skeleton is coordinated to the metal. This is more preferable.

[0037] In the above structure, the first material preferably exhibits phosphorescence.

[0038] In the above configuration, the emission spectrum of the first material is on the longest wavelength side of the emission spectrum of the second material. It is preferable that the absorption band overlaps.

[0039] In the above structure, the concentration of the second material in the light-emitting layer is 2 wt % or more and 30 wt % or less. It is preferable that:

[0040] Another embodiment of the present invention is a light-emitting device having a light-emitting layer between a pair of electrodes, The optical layer has an energy donor and an energy acceptor. The energy acceptor is It has the function of converting triplet excitons into light emission, and the energy acceptor has a five-membered ring structure. The energy acceptor has a luminophore and five or more protecting groups, and the luminophore is a fused aromatic ring. or a condensed heteroaromatic ring, and the 5 or more protecting groups each independently have 1 to 10 carbon atoms. The alkyl groups listed below, substituted or unsubstituted cycloalkyl groups with 3 to 10 carbon atoms, The energy donor has any one of the trialkylsilyl groups having a number of 3 to 12. The T1 level of the energy acceptor is higher than the S1 level of the energy donor. The triplet excitation energy of the energy acceptor is converted to the singlet excitation energy of the energy acceptor. The device is a light-emitting device that emits light originating from the energy acceptor.

[0041] In the above-mentioned configuration, the emission originating from the energy acceptor is preferably fluorescent emission. .

[0042] Another embodiment of the present invention is a light-emitting device having any of the above structures, and a color filter or a transistor. and at least one of a first transistor and a second transistor. and an electronic device having the display device and at least one of a housing and a touch sensor. Another embodiment of the present invention is a light-emitting device having any of the above structures, and a housing or a touch sensor. and at least one of a light-emitting device and a light-emitting diode. The category includes not only light-emitting devices having light-emitting devices, but also electronic devices having light-emitting devices. In this specification, the light-emitting device refers to an image display device or a light source (including a lighting device). Also, connectors such as FPC (Flexible Print Circuit) are attached to light-emitting devices. ed Circuit), TCP (Tape Carrier Package) are used. A display module with a printed wiring board at the end of the TCP. Or, the light-emitting device is mounted with an IC (Integrated Circuit) by using the COG (Chip On Glass) method. The light emitting device may also include a display module in which the display element 12 is directly mounted. Effect of the Invention

[0043] According to one embodiment of the present invention, a light-emitting device with high emission efficiency can be provided. According to one embodiment of the present invention, a highly reliable light-emitting device can be provided. In one embodiment, a light-emitting device with reduced power consumption can be provided. According to one embodiment of the present invention, a novel light-emitting device can be provided. In one aspect, a novel light-emitting device can be provided. Alternatively, a novel organic compound can be provided. .

[0044] Note that 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 are described in the specification. The disclosure of the specification, drawings, claims, etc. is self-evident, and the disclosure of the specification, drawings, claims, etc. is self-evident. From this, it is possible to extract other effects. [Brief description of the drawings]

[0045] [Figure 1]1A and 1B are schematic cross-sectional views of a light-emitting layer of a light-emitting device according to one embodiment of the present invention, and Fig. 1C is a diagram illustrating the correlation of energy levels of a light-emitting device according to one embodiment of the present invention. [Diagram 2] 2A and 2B are conceptual diagrams of conventional guest materials and guest materials used in a light-emitting device according to one embodiment of the present invention. [Diagram 3] 3A is a structural formula of a guest material used in a light-emitting device according to one embodiment of the present invention, and FIG. 3B is a ball-and-stick diagram of the guest material used in a light-emitting device according to one embodiment of the present invention. [Figure 4] Fig. 4A is a schematic cross-sectional view of a light-emitting layer of a light-emitting device according to one embodiment of the present invention, and Fig. 4B and Fig. 4C are diagrams illustrating the correlation between energy levels of a light-emitting device according to one embodiment of the present invention. [Diagram 5] Fig. 5A is a schematic cross-sectional view of a light-emitting layer of a light-emitting device according to one embodiment of the present invention, and Fig. 5B and Fig. 5C are diagrams illustrating the correlation of energy levels of the light-emitting layer of a light-emitting device according to one embodiment of the present invention. [Figure 6] FIG. 6 is a schematic cross-sectional view of a light-emitting device according to one embodiment of the present invention. [Figure 7] 7A is a top view illustrating a display device of one embodiment of the present invention, and FIG 7B is a schematic cross-sectional view illustrating a display device of one embodiment of the present invention. [Figure 8] 8A and 8B are schematic cross-sectional views illustrating a display device of one embodiment of the present invention. [Figure 9] 9A and 9B are schematic cross-sectional views illustrating a display device of one embodiment of the present invention. [Figure 10] 10A to 10D are perspective views illustrating a display module of one embodiment of the present invention. [Figure 11] 11A to 11C are diagrams illustrating electronic devices of one embodiment of the present invention. [Figure 12] 12A and 12B are perspective views illustrating a display device of one embodiment of the present invention. [Figure 13] FIG. 13 illustrates a lighting device according to one embodiment of the present invention. [Figure 14]FIG. 14 is a diagram illustrating the external quantum efficiency-luminance characteristics of a light-emitting device according to an embodiment. [Figure 15] FIG. 15 is a diagram illustrating an electroluminescence spectrum of a light-emitting device according to an example. [Figure 16] FIG. 16 is a diagram illustrating the external quantum efficiency-luminance characteristics of a light-emitting device according to an embodiment. [Figure 17] FIG. 17 is a diagram illustrating an electroluminescence spectrum of a light-emitting device according to an example. [Figure 18] FIG. 18 is a diagram illustrating the external quantum efficiency-luminance characteristics of a light-emitting device according to an embodiment. [Figure 19] FIG. 19 is a diagram illustrating an electroluminescence spectrum of a light-emitting device according to an example. [Figure 20] FIG. 20 is a diagram illustrating the external quantum efficiency-luminance characteristics of a light-emitting device according to an embodiment. [Figure 21] FIG. 21 is a diagram illustrating an electroluminescence spectrum of a light-emitting device according to an example. [Figure 22] FIG. 22 is a diagram illustrating the external quantum efficiency-luminance characteristics of a light-emitting device according to an embodiment. [Figure 23] FIG. 23 is a diagram illustrating an electroluminescence spectrum of a light-emitting device according to an example. [Figure 24] FIG. 24 is a diagram illustrating the external quantum efficiency-luminance characteristics of a light-emitting device according to an embodiment. [Diagram 25] FIG. 25 is a diagram illustrating an electroluminescence spectrum of a light-emitting device according to an example. [Figure 26] FIG. 26 is a diagram illustrating the external quantum efficiency-luminance characteristics of a light-emitting device according to an embodiment. [Figure 27] FIG. 27 is a diagram illustrating an electroluminescence spectrum of a light-emitting device according to an example. [Figure 28] FIG. 28 is a diagram illustrating the external quantum efficiency-luminance characteristics of a comparative light-emitting device according to an example. [Figure 29]FIG. 29 is a diagram illustrating an electroluminescence spectrum of a comparative light-emitting device according to an example. [Diagram 30] FIG. 30 is a diagram illustrating the relationship between the emission spectrum and the absorption spectrum in the example. [Diagram 31] FIG. 31 is a diagram illustrating the relationship between the emission spectrum and the absorption spectrum in the example. [Diagram 32] FIG. 32 is a diagram illustrating the relationship between the emission spectrum and the absorption spectrum in the example. [Diagram 33] FIG. 33 is a diagram illustrating the relationship between the emission spectrum and the absorption spectrum in the example. [Diagram 34] FIG. 34 is a diagram illustrating the relationship between the emission spectrum and the absorption spectrum in the example. [Diagram 35] FIG. 35 is a diagram illustrating the relationship between the emission spectrum and the absorption spectrum in the example. [Diagram 36] FIG. 36 is a diagram illustrating the relationship between the emission spectrum and the absorption spectrum in the example. [Figure 37] FIG. 37 is a diagram illustrating the relationship between the external quantum efficiency and the guest material concentration in the example. [Figure 38] FIG. 38 is a diagram for explaining the results of a reliability test according to an embodiment. [Figure 39] FIG. 39 is a diagram for explaining the results of a reliability test according to an embodiment. [Diagram 40] FIG. 40 is a diagram for explaining the results of a reliability test according to an embodiment. [Diagram 41] FIG. 41 is a diagram for explaining the results of a reliability test according to an embodiment. [Diagram 42] FIG. 42 is a diagram for explaining the results of a reliability test according to an embodiment. [Diagram 43] FIG. 43 is a diagram for explaining the results of a reliability test according to an embodiment. [Diagram 44] FIG. 44 is a diagram for explaining the results of a reliability test according to an embodiment. [Diagram 45]45A and 45B are diagrams illustrating NMR charts of a compound according to a reference example. [Diagram 46] FIG. 46 is a diagram illustrating an NMR chart of a compound according to a reference example. [Figure 47] FIG. 47 is a diagram illustrating an NMR chart of a compound according to a reference example. [Figure 48] FIG. 48 is a diagram illustrating an NMR chart of a compound according to a reference example. [Figure 49] FIG. 49 is a diagram illustrating the results of measuring the luminescence lifetime of a light-emitting device according to an embodiment. [Figure 50] FIG. 50 is a diagram illustrating the results of measuring the luminescence lifetime of a light-emitting device according to an embodiment. [Figure 51] FIG. 51 is a diagram illustrating the results of measuring the luminescence lifetime of a light-emitting device according to an embodiment. [Figure 52] FIG. 52 is a diagram illustrating the external quantum efficiency-luminance characteristics of a light-emitting device according to an embodiment. [Figure 53] FIG. 53 is a diagram illustrating an electroluminescence spectrum of a light-emitting device according to an example. [Figure 54] FIG. 54 is a diagram for explaining the results of a reliability test according to an embodiment. [Figure 55] FIG. 55 is a diagram illustrating the results of measuring the luminescence lifetime of a light-emitting device according to an embodiment. [Figure 56] 56A and 56B are diagrams illustrating NMR charts of a compound according to a reference example. [Figure 57] FIG. 57 is a diagram illustrating an NMR chart of a compound according to a reference example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0046] Hereinafter, the embodiment 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 are not limited to those described above without departing from the spirit and scope of the present invention. Therefore, the present invention is directed to the following embodiments and examples. The present invention should not be construed as being limited to the description of the examples.

[0047] In addition, the position, size, range, etc. of each component shown in the drawings are not necessarily shown in order to facilitate understanding. The actual position, size, range, etc. may not be shown. The present invention is not necessarily limited to the position, size, range, etc. disclosed in the drawings, etc.

[0048] In addition, in this specification, ordinal numbers such as 1st, 2nd, etc. are used for convenience. In some cases, the order of steps or layers may not be indicated. For example, "first" may be replaced with "second" or " " can be appropriately replaced with "the third" etc. The ordinal numbers used to identify an aspect of the present invention may not match those used in the present invention. be.

[0049] In addition, in this specification and the like, when explaining the configuration of the invention using drawings, The reference numerals may be commonly used among different drawings.

[0050] 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:

[0051] In the present specification and the like, the singlet excited state (S * ) is a single charge 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 an excited energy. The lowest triplet excited energy level is the lowest triplet excited state (T1 In this specification and the like, the term "singlet excited state" refers to the excited energy level of the singlet excited state. Even when written as states and singlet excited energy levels, the S1 state and S1 level The triplet excited state and triplet excited energy level are also used. Even in this case, it may refer to a T1 state and a T1 level.

[0052] In the present specification and the like, a fluorescent material is a material that emits a fluorescent 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 from a triplet excited state. 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.

[0053] In this specification, the blue wavelength range is from 400 nm to 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 emission is within this wavelength region. It has at least one emission spectrum peak. The red wavelength region is 580 nm. and the red emission has at least one emission spectrum in the wavelength range. It has a peak.

[0054] (Embodiment 1) In this embodiment, a light-emitting device according to one embodiment of the present invention will be described below with reference to FIGS. This is explained below.

[0055] <Example of light-emitting device configuration> First, a structure of a light-emitting device according to one embodiment of the present invention will be described with reference to FIGS. 1A to 1C. This is explained below.

[0056] FIG. 1A is a schematic cross-sectional view of a light-emitting device 150 according to one embodiment of the present invention.

[0057] The light-emitting device 150 has a pair of electrodes (electrode 101 and electrode 102). The EL layer 100 is provided between the electrodes. The EL layer 100 has at least a light-emitting layer 130. do.

[0058] In addition to the light-emitting layer 130, the EL layer 100 shown in FIG. 1A also includes a hole injection layer 111, a hole transport layer 121, and a hole transport layer 122. The light-emitting layer 112 has functional layers such as an electron transport layer 118 and an electron injection layer 119 .

[0059] In this embodiment, of the pair of electrodes, electrode 101 is an anode, and electrode 1 Although the description will be given assuming that 02 is a cathode, the configuration of the light emitting device 150 is not limited to this. That is, the electrode 101 is a cathode, the electrode 102 is an anode, and the layers between the electrodes are stacked in reverse order. That is, from the anode side, the hole injection layer 111, the hole transport layer 112, and If the light-emitting layer 130, the electron transport layer 118, and the electron injection layer 119 are laminated in this order, good.

[0060] The configuration of the EL layer 100 is not limited to the configuration shown in FIG. 1A. At least one selected from the group consisting of a hole transport layer 112, an electron transport layer 118, and an electron injection layer 119. Alternatively, the EL layer 100 may have a hole or electron injection barrier. , improve the transportability of holes or electrons, inhibit the transportability of holes or electrons, Alternatively, the structure may have a functional layer having a function of suppressing the quenching phenomenon caused by the electrode. Each functional layer may be a single layer or a laminate of multiple layers. It's fine.

[0061] <Light-emitting mechanism of light-emitting devices> Next, the light emitting mechanism of the light emitting layer 130 will be described below.

[0062] In the light-emitting device 150 according to one embodiment of the present invention, a pair of electrodes (electrode 101 and electrode 1 02) By applying a voltage between the cathode and the anode, electrons flow from the cathode and holes flow from the anode. Each of these electrons is 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) The statistical probability is 1:3. In other words, 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 not expected to contribute to light emission. It is important to improve the luminous efficiency of light-emitting devices by increasing the The optical layer 130 is made of a material having a function of converting triplet excitation energy into light emission. It is preferable to use:

[0063] As a material that can convert triplet excitation energy into light emission, phosphorescence In the present specification, etc., a compound capable of emitting light (hereinafter, also referred to as a phosphorescent material) is included. In this regard, phosphorescent materials are materials that emit light at temperatures between room temperature and the temperature obtained with liquid nitrogen (for example, 77K). It refers to a compound that exhibits phosphorescence but does not exhibit fluorescence in any temperature range. The phosphorescent material preferably has a metal element with a large spin-orbit interaction. Transition metal elements are preferred, particularly platinum group elements (elements of groups 8 to 10 and periods 5 and 6). Elements (Ruthenium (Ru), Rhodium (Rh), Palladium (Pd), Osmium (Os) , iridium (Ir), or platinum (Pt) is preferred. By having the symmetry, the transition probability for the direct transition between the singlet ground state and the triplet excited state is This is preferable because it can increase

[0064] In addition, materials that have the function of converting triplet excitation energy into luminescence include TADF materials are materials in which the difference between the S1 level and the T1 level is small. By reverse intersystem crossing, triplet excitation energy is converted to singlet excitation energy. Therefore, it is a material that can convert triplet excitation energy. It is up-converted to singlet excitation energy by a small amount of thermal energy (e.g., at room temperature) Reverse intersystem crossing is possible, and singlet excited states can be generated efficiently. Excited states formed in the following substances (exciplexes, exciplexes or E The triplet excited electrons (also called xciplexes) have a very small difference between the S1 and T1 levels. It functions as a TADF material that can convert the energy from the ZnO to singlet excitation energy. do.

[0065] As an index of the T1 level, the phosphorescence spectrum observed at low temperatures (e.g., 10 K) is used. As for the TADF material, the tangent line at the short wavelength side of the fluorescence spectrum is The energy of the wavelength of the extrapolated line is taken as the S1 level, and the phosphorescence spectrum is placed at the short wavelength side. When a tangent line is drawn at the wavelength of the extrapolated line, the energy of the wavelength is taken as the T1 level. It is preferable that the difference in 1 is 0.2 eV or less.

[0066] FIG. 1B is a schematic cross-sectional view showing a light-emitting layer 130 of a light-emitting device according to one embodiment of the present invention. In one embodiment of the invention, the light-emitting layer 130 comprises Compound 131, Compound 132, and Compound 133. Compound 133 has the function of converting triplet excitation energy into luminescence and has a five-membered ring structure. Compound 132 has the function of converting singlet excitation energy into luminescence and is also a protective Since fluorescent materials are highly stable, it is important to obtain highly reliable light-emitting devices. It is preferable to use a fluorescent material as compound 132. Compound 131 is a host material. It is preferable that carrier recombination occurs on compound 131. In light-emitting devices, the singlet excitation energy of the excitons generated by carrier recombination in compound 131 is Both the energy and triplet excitation energy are transferred via compound 133 to compound 132. It is preferable that the compound 132 emits light by transferring energy to the singlet excited state of the compound 132. In the optical layer 130, compound 133 is an energy donor and compound 132 is an energy accessor. In FIG. 1B, the light-emitting layer 130 contains the compound 131 as a host material, the compound The fluorescent layer uses compound 132 as a guest material. Compound 133 acts as an energy donor. The light-emitting layer 130 emits light derived from the guest material compound 132. It is possible.

[0067] <Emitting layer configuration example 1> FIG. 1C illustrates the energy levels in light-emitting layer 130 of light-emitting device 150 according to one embodiment of the present invention. The light-emitting layer 130 shown in FIG. 1B is composed of a compound 131, a compound 132, and and compound 133. In one embodiment of the present invention, compound 132 has a protecting group. Compound 133 is a fluorescent material that can convert triplet excitation energy into luminescence. In this configuration example, the compound 133 is a phosphorescent material. .

[0068] In addition, the energy level relationship between the compound 131 and the compound 132 in the light-emitting layer 130 is The relationship is shown in Figure 1C. The notations and symbols in Figure 1C are as follows: ·Comp(131): Compound 131 ·Comp(133): Compound 133 ·Guest(132): Compound 132 ·S C1 : S1 level of compound 131 T C1 :T1 level of compound 131 T C3 :T1 level of compound 133 T G :T1 level of compound 132 ·S G : S1 level of compound 132

[0069] In the light-emitting device of one embodiment of the present invention, the compound 131 in the light-emitting layer 130 The recombination of carriers occurs mainly in the nuclei, resulting in the formation of singlet and triplet excitons. Here, compound 133 is a phosphorescent material, so T C3 ≦T C1 Select materials that have the following relationship: By selecting the 131-C bond, both the singlet and triplet excitation energies generated in compound 131 can be converted to compound 13. 3T C3(Fig. 1C Route A1). Note that some carriers can , which can be recombined with compound 133.

[0070] The phosphorescent material used in the above configuration contains heavy atoms such as Ir, Pt, Os, Ru, and Pd. As described above, in this configuration example, the phosphorescent material is preferably an energy donor. Since the phosphorescent material acts as a photoluminescent material, the quantum yield can be high or low. When used as an energy donor, the triplet excited energy level of the energy donor Energy transfer from the photoelectron beam to the singlet excited energy level of the guest material (energy acceptor). Therefore, the triplet excitation energy of compound 133 is looped. The S1 level (S G ) In route A2, compound 133 is the energy donor and compound 132 is the In this case, T C3 ≧S G Then, compound 133 The excitation energy of is efficiently transferred to the singlet excited state of the guest material, compound 132. Specifically, the phosphorescence spectrum of compound 133 has a tangent line at the short wavelength side. Then, the energy of the wavelength of the extrapolated line is T C3 The absorption spectrum of compound 132 is The wavelength of the absorption edge or the wavelength of the extrapolated line drawn at the base of the short wavelength side of the emission spectrum The energy of S G When this is done, T C3 ≧S G It is preferable that:

[0071] Here, in the light-emitting layer 130, the compounds 131, 132 and 133 are mixed together. Therefore, the triplet excitation of compound 133 competes with the above routes A1 and A2. The process in which the excitation energy is converted into triplet excitation energy of compound 132 (Figure 1C Route A) 3) may occur. Since compound 132 is a fluorescent material, the triplet excited electrons of compound 132 may In other words, when the energy transfer of route A3 occurs, the luminescence device The light emission efficiency of the device will decrease. C3 From T G Energy transfer to Step A3 is not directly, but the T G Once the energy reaches a higher triplet excited state than Then, by internal conversion, T G There may be a route that leads to this, but this process is omitted in the figure. In the following description, the undesirable thermal deactivation process, i.e., T G fart The energy transfer processes are all similar.

[0072] Here, the mechanism of intermolecular energy transfer is fluorescence resonance energy transfer (FRET). uorescence Resonance Energy Transfer or Pheno The Dexter mechanism (also called dipole-dipole interaction) and the Einstein mechanism (electron exchange interaction) The energy acceptor, compound 132, is a fluorescent material. Therefore, the energy transfer along route A3 is dominated by the Dexter mechanism. The photocatalytic mechanism is based on the interaction of the energy donor compound 131 and the energy acceptor compound 132. 132 occurs significantly at a distance of 1 nm or less. Therefore, in order to suppress route A3, The distance between the host material and the guest material, i.e., the distance between the energy donor and the energy acceptor It is important to keep the distance.

[0073] In addition, the singlet excited energy level of compound 131 (S C1 ) from the triplet of compound 132 Excitation energy level (T G ) is the singlet ground state in compound 132. Since direct transition from the excited state to the triplet excited state is forbidden, the main energy transfer process is Since this is unlikely to occur, it is not illustrated.

[0074] T in Figure 1C G is the energy level originating from the luminophore in the energy acceptor. Therefore, in order to suppress route A3, it is necessary to have an energy donor and It is important to keep the distance between the energy acceptor and the luminophore. A common method to increase the distance between the luminophores of the donor and energy acceptor is to One of the methods to achieve this is to lower the concentration of the energy acceptor in the mixed film of these compounds. However, when the concentration of the energy acceptor in the mixed film is reduced, the energy donor Not only does the Dexter mechanism of energy transfer occur from the nucleus to the energy acceptor, Energy transfer based on the Förster mechanism is also suppressed. In that case, route A2 is Because it is based on the Förster mechanism, it can cause problems such as a decrease in the light-emitting efficiency and reliability of light-emitting devices. A problem arises.

[0075] Therefore, the inventors have proposed a method to increase the distance between the energy acceptor and the energy donor. By using a fluorescent material having a protecting group for the light-emitting element, the decrease in the light-emitting efficiency can be suppressed. By having a protecting group, the fluorescent material has a bulky energy acceptor. It can be used as a target.

[0076] <Concept of fluorescent materials having protecting groups> FIG. 2A shows a typical fluorescent material that does not have a protecting group as a guest material. FIG. 2B shows a schematic diagram of the case where the fluorine-containing compound is dispersed in a light-emitting device according to one embodiment of the present invention. The concept of dispersing a fluorescent material having a protecting group as a guest material in a host material. The host material is called the energy donor and the guest material is called the energy acceptor. Here, the protecting group has a function of increasing the distance between the luminophore and the host material. In FIG. 2A, the guest material 301 has a luminophore 310. The guest material 301 has On the other hand, in FIG. 2B, the guest material 30 2 has a luminophore 310 and a protecting group 320. Also, in FIG. 2A and FIG. 2B, the guest material The luminophore 301 and the guest material 302 are surrounded by the host material 330. Since the distance between the host material and the guest material is short, energy transfer from the host material 330 to the guest material 301 occurs. As the energy transfer by the Förster mechanism (Route B1 in Figures 2A and 2B), Both the Dexter mechanism and route B2 in Fig. 2A and Fig. 2B occur. The triplet excitation energy is transferred from the host material to the guest material by the Dexter mechanism. When energy transfer occurs and a triplet excited state is generated in the guest material, the guest material becomes a fluorescent material. In some cases, the triplet excitation energy is non-radiatively deactivated, which is one of the causes of a decrease in luminous efficiency.

[0077] On the other hand, in FIG. 2B, the guest material 302 has a protecting group 320. The distance between the ion exchange layer 10 and the host material 330 can be increased. Energy transfer (route B2) can be suppressed.

[0078] 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 by the Förster mechanism. It is known that energy transfer is also affected by the distance between the host material and the guest material. In general, the distance between the host material 330 and the luminophore 310 of the guest material 302 is 1 nm or less. The Dexter mechanism is dominant, and the Förster mechanism is dominant in the range of 1 nm to 10 nm. In general, the distance between the host material 330 and the luminophore 310 contained in the guest material 302 is 1 Above 0 nm, energy transfer is unlikely to occur.

[0079] Therefore, it is preferred that the protecting group 320 extend from the luminophore 310 within a range of 1 nm to 10 nm. It is 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 via the Dexter mechanism, This allows for the efficient use of energy transfer via the Förster mechanism. Light emitting devices can be made with high optical efficiency.

[0080] 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 dextran concentration. The energy transfer rate of the photoelectron mechanism also increases, resulting in a decrease in the luminous efficiency. It was difficult to increase the concentration of the guest material. In fluorescent devices using functional materials as host materials, Light-emitting devices with low guest material concentrations of 1 wt% or less have been reported.

[0081] On the other hand, in the light-emitting device according to one embodiment of the present invention, a guest molecule having a protecting group in a light-emitting layer is Therefore, the material is made of ferroelectric material, which suppresses the energy transfer caused by the Dexter mechanism. The energy transfer by the star mechanism can be efficiently utilized, so the energy The concentration of the scepter guest material can be increased, resulting in the Dexter mechanism By suppressing the energy transfer by the ion exchange mechanism and increasing the rate of energy transfer by the Förster mechanism, The concentration of the guest material is adjusted to the host material concentration. On the other hand, 2 wt% to 30 wt% is preferable, and 5 wt% to 20 wt% is more preferable. % or less, and more preferably 5 wt % to 15 wt %. This increases the rate of energy transfer via the Förster mechanism, resulting in higher luminescence efficiency. Furthermore, it is possible to convert triplet excitation energy into light emission. By using a material with the same function as the host material, it is possible to achieve high-quality light emission equivalent to that of phosphorescent devices. It is possible to fabricate a fluorescent light-emitting device with high luminous efficiency. Since the luminous efficiency can be improved by using the above-mentioned method, a highly reliable light-emitting device can be fabricated. .

[0082] In particular, the effect of the light-emitting device according to one embodiment of the present invention is that the light-emitting device can be realized by simply using a highly stable fluorescent material. This not only improves reliability, but also increases the energy transfer that occurs when The quenching rate constant of the quenching process increases with time. As the temperature increases, the light emitting device emits less light, i.e., the brightness of the light emitting device decreases. However, as described above, one aspect of the present invention is to prevent energy transfer via the Dexter mechanism. While suppressing the vibration, the energy transfer speed by the Förster mechanism is faster than that of conventional light-emitting devices. This reduces the effect of competition with the quenching process and extends the life of the light-emitting device. It can be made to live.

[0083] Here, the term "luminophore" refers to an atomic group (skeleton) that causes light emission in a fluorescent material. The photophores generally have pi bonds and preferably contain aromatic rings, and may be fused aromatic or fused rings. In another embodiment, the luminophore has a transition on the ring plane. It can be thought of as a group of atoms (skeleton) containing aromatic rings within which a dipole vector resides.

[0084] The condensed aromatic ring or condensed heteroaromatic ring may be a phenanthrene skeleton, a stilbene skeleton, an acyclic skeleton, or a cyclic heteroaromatic ring. Examples of the skeleton include lysine skeleton, phenoxazine skeleton, and phenothiazine skeleton. In particular, naphthalene skeleton is skeleton, anthracene skeleton, fluorene skeleton, chrysene skeleton, triphenylene skeleton, tetra Cene skeleton, pyrene skeleton, perylene skeleton, coumarin skeleton, quinacridone skeleton, naphthobisbe A fluorescent material having a benzofuran skeleton is preferred because it has a high fluorescence quantum yield.

[0085] In addition, the protecting group is a group that has a triplet excitation energy higher than the T1 level of the luminophore and the host material. Therefore, a saturated hydrocarbon group can be preferably used. This is because the triplet excitation energy level of the substituents that do not have π bonds is high. Substituents that do not have this function do not transport carriers (electrons or holes). The saturated hydrocarbon group has little effect on the excited state or carrier transport properties of the host material. In addition, the distance between the luminophore and the host material can be increased. In organic compounds that simultaneously have a substituent having a π-conjugated system, The frontier orbital {HOMO(Highest Occupied Molecular lar Orbital (also called the highest occupied orbital) and LUMO (Lowest Unoccupied Orbital) There is a lowest unoccupied molecular orbital (Least Unoccupied Orbital). In many cases, the luminophores have frontier orbitals. In the Dexter mechanism, energy transfer involves an energy donor and an energy acceptor. -The overlap of the HOMO and the LUMO of both are important. Therefore, saturated carbon By using a hydride group as a protecting group, the frontier of the host material, which is an energy donor, can be expanded. The distance between the frontier orbital of the guest material, which is the energy acceptor, is large. This can prevent the energy transfer via the Dexter mechanism from occurring.

[0086] Specific examples of the protecting group include alkyl groups having 1 to 10 carbon atoms. Since it is necessary to increase the distance between the group and the host material, the protecting group is preferably a bulky substituent. In other words, it is preferable that the substituent has a large steric hindrance. The alkyl groups listed below, substituted or unsubstituted cycloalkyl groups with 3 to 10 carbon atoms, A trialkylsilyl group having a number of 3 to 10 can be preferably used. The substituent is preferably a bulky branched alkyl group. In addition, if the substituent has a quaternary carbon, the substituent becomes bulky. This is particularly preferred since it results in a high substituent.

[0087] In addition, it is preferable that one luminophore has five or more protecting groups. The entire luminophore can be covered with a protecting group, allowing the distance between the host material and the luminophore to be adjusted appropriately. In addition, Figure 2B shows the direct bond between the luminophore and the protecting group. However, it is more preferred 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 aryl group or an amino group. By binding the protecting group to the luminophore via Therefore, if the luminophore and the protecting group are not directly bonded, one protecting group is required. If the luminophores have four or more, the energy transfer via the Dexter mechanism is effectively suppressed. It can be controlled.

[0088] 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 protective groups are located on the outermost side when the molecular structure is viewed from the center of the luminophore. It is preferable to place

[0089] <Examples of fluorescent materials with protecting groups and their molecular structures> Here, a light-emitting device according to one embodiment of the present invention, which is represented by the following structural formula (102), can be used. N,N'-[(2-tert-butylanthracene)-9,1 0-diyl]-N,N'-bis(3,5-di-tert-butylphenyl)amine (abbreviation The structure of 2tBu-mmtBuDPhA2Anth is shown below. In hA2Anth, the anthracene ring is the luminophore, and the tertiary butyl (tBu ) group acts as a protecting group.

[0090] [ka]

[0091] A ball-and-stick model representation of the above 2tBu-mmtBuDPhA2Anth is shown in FIG. 3B. In addition, in Figure 3B, 2tBu-mmtBuDPhA2Anth is connected in the direction of the arrow in Figure 3A (antrail). The shaded area in Figure 3B represents the light-emitting area. The anthracene ring plane is a protective group, and the tBu group is located directly above the anthracene ring plane. For example, the atom indicated by the arrow (a) in FIG. 3B is in the The atom indicated by the arrow (b) is the carbon atom of the tBu group that overlaps with the shaded portion. The hydrogen atoms of the overlapping tBu groups. That is, 2tBu-mmtBuDPhA2Anth In the case of the luminophore, the atoms constituting the protecting group are located directly above one of the luminophore faces, and the atoms constituting the protecting group are located directly above the other face. By adopting this structure, the guest material is dispersed in the host material. Even in the dispersed state, the luminophores are oriented in both the planar and perpendicular directions of the anthracene ring. In this case, the distance between the anthracene ring and the host material can be increased, and the Dexter mechanism This can suppress the energy transfer.

[0092] In addition, the energy transfer by the Dexter mechanism is, for example, In the case of a transition between the OMO and LUMO, the overlap of the HOMOs of both the host and guest materials The HOM of both the host material and the guest material and the overlap of the LUMO of both materials are important. When O and LUMO overlap, the Dexter mechanism occurs significantly. In order to suppress this, it is important to suppress the overlap of the HOMO and LUMO of both materials. In other words, it is important to keep the distance between the framework involved in the excited state and the host material. In fluorescent materials, the luminophore often has both the HOMO and the LUMO. For example, the HOMO and LUMO of the guest material are above and below the plane of the luminophore (2 tBu-mm In the case of tBuDPhA2Anth, the anthracene ring is extended upward and downward. In this case, it is important in the molecular structure that the luminophore be covered above and below its plane with protecting groups.

[0093] In addition, condensed aromatic rings and condensed heteroaromatic rings that function as luminophores, such as pyrene rings and anthracene rings, The aromatic ring has a transition dipole vector on the ring plane. Therefore, in FIG. 3B, -mmtBuDPhA2Anth is the plane where the transition dipole vector exists, i.e., the anthra It is preferable that the tBu group, which is a protecting group, overlaps the sen ring directly on the plane of the ring. At least one of the atoms constituting the multiple protecting groups (tBu groups in FIG. 3A and FIG. 3B) The first is a fused aromatic ring or a fused heteroaromatic ring (anthracene ring in FIG. 3A and FIG. 3B). and at least one of the atoms constituting the multiple protecting groups is located directly on one surface of is located directly above the other face of the condensed aromatic ring or condensed heteroaromatic ring. This allows the distance between the luminophore and the host material to be controlled even when the guest material is dispersed in the host material. This can increase the distance between the molecules and suppress the energy transfer caused by the Dexter mechanism. In addition, it is preferable that the tBu group is arranged so as to cover a luminophore such as an anthracene ring. I wish.

[0094] <Reasons for using phosphorescent materials with five-membered ring skeletons> Next, let us consider the energy donor. By using a material with a five-membered ring structure as the active material, the Förster mechanism can be effectively utilized. As described below, we found that energy transfer can be utilized. As the phosphorescent material, a phosphorescent material having a five-membered ring skeleton can be preferably used.

[0095] The five-membered ring skeleton is preferably a heteroaromatic ring skeleton, for example, a pyrrole skeleton or a pyrazole skeleton. imidazole skeleton, triazole skeleton or tetrazole skeleton, benzimidazole In particular, imidazole skeleton, triazole skeleton, etc. Phosphorescent materials having a cyclic structure, a benzimidazole structure, or a naphthoimidazole structure are preferred. Among them, metal complexes having the above skeleton as a ligand are preferred, and metal complexes having the above skeleton as a ligand and a central gold Metals in groups 8 to 10 and periods 5 and 6 (Ru, Rh, Pd, Os, Ir or P t), and among them, Ir complexes are particularly preferred. For example, a naphthoimidazole skeleton is an example of a skeleton having an imidazole skeleton.

[0096] Phosphorescent materials that have a five-membered ring structure as a ligand tend to have a high HOMO level. In 130, the material with a high HOMO level is treated as the above-mentioned compound 133 (energy donor). When used as a light-emitting device, when a current is applied to the light-emitting device 150, the guest material (energy The compound 132, which is an acceptor, can suppress the trapping of holes. The excitation of the compound by the electric current can be suppressed by the above-mentioned Except for exciplexes, they occur when a hole and an electron are trapped on the same molecule. Therefore, H By using a material with a high OMO level for compound 133, current excitation on compound 132 (Direct excitation of compound 132) can be suppressed. When compound 132 is directly excited, Since compound 132 is a fluorescent material, the triplet excitons generated do not contribute to light emission, and the luminescence efficiency is Therefore, the HOMO level of phosphorescent materials with five-membered ring structures is high. In this case, the phosphorescent material can be used as compound 133 to produce a light-emitting device 150. Therefore, the decrease in the luminous efficiency can be suppressed.

[0097] <Phosphorescent materials with five-membered ring structures as bulky energy donors> Here, a phosphorescent material having a five-membered ring skeleton in a ligand that can be used in one embodiment of the present invention An example of an Ir complex having a five-membered ring skeleton in the ligand is shown below. diPrp)3 has a triazole skeleton as a five-membered ring skeleton, and fac-Ir(pbi-d iBup)3 is an Ir complex having an imidazole skeleton.

[0098] [ka]

[0099] As in the above-mentioned Ir complex, the ligand has a five-membered ring skeleton, and the five-membered ring skeleton has two or more When a skeleton containing a nitrogen atom, such as an imidazole skeleton or a triazole skeleton, is used, the metal and There are nitrogen atoms that are not coordinated. At least one of the nitrogen atoms that is not coordinated with the metal is involved in a double bond. Since the aromatic ring is not present, it can have a substituent while maintaining the aromatic ring (among the Ir complexes mentioned above, The substituents include hydrogen, alkyl groups, aromatic hydrocarbon groups, etc. Examples of the substituent include a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms. In particular, it is preferable that the alkyl group is an unsubstituted phenyl group or an alkyl group having 1 to 6 carbon atoms. It is preferable that the phenyl group further has fluorine, silyl, or a plurality of phenyl groups. An electron-withdrawing group such as an ano group or a fluoroalkyl group may be bonded. The thermal stability and sublimability of the Ir complex can be improved.

[0100] Therefore, when a compound having a five-membered ring skeleton is used as a ligand of an Ir complex, the nitrogen atom The substituent may be a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms. By having such a substituent, the ligand has a bulky structure with large steric hindrance. As a result, the Ir complex has a bulky structure. When a compound having this property is used as a ligand for a phosphorescent material, the Ir complex tends to have a bulky structure. .

[0101] Here, let us consider the case where the Ir complex is excited. In many cases, the Ir complex, which is a phosphorescent material, In this case, the lowest triplet excited level is derived from triplet MLCT. is the Ir atom and the part of the ligand that is coordinated to the Ir atom (the nitrogen that is coordinated to the Ir atom). They are often present in the vicinity of an ortho-metalated carbon atom.

[0102] Here, let us consider the case where an Ir complex having a bulky ligand is dispersed in the light-emitting layer. This allows the distance between the Ir atoms in the Ir complex and the material surrounding the Ir complex to be increased. In other words, the deactivation of triplet excitation energy by the Dexter mechanism can be suppressed.

[0103] Here, let us consider the case where the bulky Ir complex is used in the above-mentioned compound 133. Excitation energy deactivation from compound 133 to compound 132 by the Dexter mechanism (Route A) 3) can be suppressed. Therefore, the energy transfer via route A2 (Förster mechanism) From the above, it is possible to efficiently utilize the five-membered ring structure as a ligand. By using an Ir complex having this property, a light-emitting device with high luminous efficiency can be obtained.

[0104] In addition, as mentioned above, an Ir complex having a five-membered ring structure as a ligand was used as an energy donor. By doing so, it is possible to suppress the transfer of excitation energy by the Dexter mechanism. When an Ir complex having a five-membered ring as a ligand is used as an energy donor, Even if the number of protecting groups of a certain energy acceptor is small, it is possible to obtain an energy acceptor by route A2. In this case, the energy acceptor is 1 It is preferable that the luminophore has at least two protecting groups, and it is preferable that the luminophore has three or more protecting groups. It is more preferable that the five-membered ring used as the ligand of the Ir complex has four or more of them. The skeleton is preferably an imidazole skeleton or a triazole skeleton. In the formula, a nitrogen atom that is not bonded to Ir and is not involved in a double bond is substituted or substituted with More preferably, the aryl group has a structure to which an unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms is bonded. In addition, when the aromatic hydrocarbon group is a phenyl group and the phenyl group has a substituent, It is more preferable that the substituent has an alkyl group having 1 to 6 carbon atoms.

[0105] Specific examples of the aromatic hydrocarbon group having 6 to 13 carbon atoms include a phenyl group, a biphenyl group, Examples of the alkyl group having 1 to 6 carbon atoms include a naphthyl group and a fluorenyl group. is a methyl group, an ethyl group, a propyl group, a pentyl group, a hexyl group, a cyclohexyl group, Bornyl group, adamantyl group, isopropyl group, sec-butyl group, isobutyl group, t ert-butyl group, isopentyl group, sec-pentyl group, tert-pentyl group, neo Pentyl group, isohexyl group, 3-methylpentyl group, 2-methylpentyl group, 2-ethyl Examples of the alkyl group include dimethylbutyl, 1,2-dimethylbutyl, and 2,3-dimethylbutyl. The aromatic hydrocarbon group having 6 to 13 carbon atoms and the alkyl group having 1 to 6 carbon atoms are not limited to these. Not determined.

[0106] In addition, the triplet excitation energy of the Ir complexes with a five-membered ring structure as a ligand is not limited to the six-membered ring structure. The Ir complexes that are composed of these compounds tend to have higher fluorescence intensities than the Ir complexes that are composed of these compounds. Therefore, the compound 132 is compared to the green and blue colors. When a fluorescent material that emits light at a relatively short wavelength is used as the energy acceptor, An Ir complex having a skeleton as a ligand can be suitably used as an energy donor.

[0107] As will be described later, in the energy transfer by the Förster mechanism, the energy Scepter absorption spectrum (the longest wavelength absorption band (mainly the absorption band due to the S1 level)) It is preferable that the emission spectrum of the energy donor overlaps with that of the blue to green. A fluorescent material having an emission peak on the relatively short wavelength side (400 nm to 580 nm) In the case of using a fluorescent material, the absorption band of the fluorescent material is also on the short wavelength side. In order to increase the overlap of the emission spectra of the electron donors, the triplet excitation energy must be It is preferable to use a large energy donor.

[0108] In addition, by using a phosphorescent material with a five-membered ring structure in compound 133, the Dexter mechanism was While suppressing the energy transfer by the ion exchange mechanism, the energy transfer by the Förster mechanism is efficiently utilized. Therefore, the compound 133, which is an energy donor, is added to the light-emitting layer 130. As a result, the energy transfer by the Dexter mechanism can be improved. The two fundamental goals of this study are to suppress the movement of the nucleus while increasing the speed of energy transfer via the Förster mechanism. The concentration of compound 133 is 2w relative to the host material. % or more and 30 wt % or less is preferable, and more preferably 5 wt % or more and 20 wt % or less is more preferable. The content of the ferrite is preferably 5 wt% or more and 15 wt% or less. This increases the energy transfer rate through the photocatalytic mechanism, resulting in a light-emitting device with high luminous efficiency. In addition, the luminous efficiency can be improved by using a highly stable fluorescent material. Therefore, a highly reliable light-emitting device can be fabricated. It is preferable that the concentrations of both the fluorescent material, Compound 132, are high. It is preferable that the concentrations of Compound 133 and Compound 132 are as high as possible. The concentration ratio of the substance 132 is preferably 1:0.2 or more and 1:5 or less, and more preferably 1:0.5 or more and 1:2 or less. More preferred.

[0109] <Emitting layer configuration example 2> FIG. 4C shows the energy levels in the light-emitting layer 130 of the light-emitting device 150 according to one embodiment of the present invention. The light-emitting layer 130 shown in FIG. 4A is composed of a compound 131, a compound 132, and In one embodiment of the present invention, compound 132 is a fluorescent material. In this configuration example, compound 131 and compound 133 form an exciplex. In addition, when compound 133 is a phosphorescent material having a five-membered ring skeleton, This will be explained below.

[0110] The combination of Compound 131 and Compound 133 is a combination capable of forming an exciplex. However, one of them is a compound having a 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 In the case of a combination of a compound having electron transport properties and a compound having electron transport properties, the mixing ratio It is possible to easily control the carrier balance by using the hole transporting property. The compound having the above property and the compound having the electron transport property are preferably in the range of 1:9 to 9:1 (weight ratio). In addition, by having this configuration, it is possible to easily control the carrier balance. Therefore, the carrier recombination region can be easily controlled. Therefore, it is suitable as a material with hole transport properties. can be used.

[0111] In addition, the combination of compound 131 and the host material that efficiently forms an exciplex is The HOMO level of one of the compounds, compound 133, is higher than that of the other, and one of the LUMs It is preferable that the HOMO level of compound 131 is higher than the LUMO level of the other compound. 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 132. It may be equivalent to the LUMO level of 33.

[0112] 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.

[0113] For example, when compound 133 has a hole transporting property and compound 131 has an electron transporting property, As shown in the energy band diagram in FIG. 4B, the HOMO level of compound 133 is The HOMO level of compound 133 is preferably higher than the HOMO level of compound 131. It is preferable that the level is higher than the LUMO level. By making such an energy level correlation, Carriers, that is, holes and electrons, are injected from a pair of electrodes (electrodes 101 and 102). However, Compound 133 and Compound 131 are preferred because they are easily injected.

[0114] In FIG. 4B, Comp(131) represents compound 131, and Comp(133) represents compound 132. ) represents compound 133, and ΔE C1 The energy between the LUMO and HOMO levels of compound 131 is represents the energy difference, ΔE C3 is the energy between the LUMO and HOMO levels of compound 133. - represents the difference, ΔE E is the energy difference between the LUMO level of compound 131 and the HOMO level of compound 133. The notation and symbol represent the energy difference.

[0115] In addition, the exciplex formed by compound 131 and compound 133 has a HOMO and compound 131 becomes an exciplex having a LUMO molecular orbital. The excitation energy of the exciplex is the LUMO level of compound 131 and the HOMO level of compound 133. Energy difference between the levels (ΔE E ) and the LUMO and HOMO levels of compound 131 are Energy difference between the levels (ΔE C1 ) and the relationship between the LUMO and HOMO levels of compound 133 Energy difference (ΔE C3 ) is smaller than that of Compound 131 and Compound 133. By forming an exciplex at , it is possible to form an excited state at a lower excitation energy. In addition, since the excitation energy is lower, the exciplex has a stable excited state. It can be formed.

[0116] In addition, the compounds 131, 132, and 133 in the light-emitting layer 130 The correlation between the energy levels is shown in FIG. 4C. The notations and symbols in FIG. 4C are as follows: It is. ·Comp(131): Compound 131 ·Comp(133): Compound 133 ·Guest(132): Compound 132 ·S C1 : S1 level of compound 131 T C1 :T1 level of compound 131 ·S C3 : S1 level of compound 133 T C3 : S1 level of compound 133 ·S G : S1 level of compound 132 TG :T1 level of compound 132 ·S E : S1 level of the exciplex T E :T1 level of the exciplex

[0117] In the light-emitting device of one embodiment of the present invention, the compound 131 in the light-emitting layer 130 The S1 level of the exciplex (S E ) and the T1 level of the exciplex ( T E ) are adjacent energy levels (see route A4 in Figure 4C).

[0118] Excitation energy levels of exciplexes (S E and T E ) is a compound that forms an exciplex. The S1 levels (S C1 and S C3 ) is lower, It is possible to form an excited state with lower excitation energy. This allows the emission device The driving voltage of the vice 150 can be reduced.

[0119] 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. The singlet excitation energy of the exciplex is rapidly converted to the compound You can move to 132 (Fig. 4C Route A6). E ≧S G is In route A6, an exciplex is the energy donor, and compound 132 is It acts as an energy acceptor, specifically, at the short wavelength of the fluorescence spectrum of the exciplex. Draw a tangent line at the long tail and let the energy of the wavelength of the extrapolated line be S E Compound 132 The energy of the wavelength of the absorption edge of the absorption spectrum or the short wavelength tail of the fluorescence spectrum Draw a tangent line and calculate the wavelength energy of the extrapolated line as S G When this is done, S E ≧S G To be is preferred.

[0120] In order to enhance the TADF property, the T1 levels of both compounds 131 and 133, Nawachi T C1 and T C3 But, T E It is preferable that the compound is more than 100%. The emission peak wavelengths on the shortest wavelength side of the phosphorescence spectra of Compound 131 and Compound 133 are It is also preferable that the wavelength is equal to or less than the maximum emission peak wavelength of the exciplex. Draw a tangent line at the short wavelength side of the optical spectrum, and let the energy of the wavelength of the extrapolated line be T. 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 C1 and T C3 When To, T E -T C1 ≦0.2 eV and T E -T C3 It is preferable that it is ≦0.2 eV. .

[0121] In this configuration 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. It is possible to form an exciplex that can convert the energy of the state into light emission. The triplet excited energy level (T E ) can be an energy donor level, so T E The singlet excited energy level (S G ) or more is preferable. Specifically, in the short wavelength tail of the emission spectrum of an exciplex using a heavy atom, Draw a tangent line and estimate the wavelength energy of the extrapolated line as T E The absorption spectrum of compound 132 Draw a tangent at the energy of the absorption edge wavelength or at the short wavelength tail of the emission spectrum. The extrapolated value of the wavelength energy is S G When this is done, T E ≧S G It is preferable that:

[0122] By making such a correlation of energy levels, the triplet excitation energy of the generated exciplex can be calculated. The triplet excited energy level (T E ) directly or from singlet excitation energy - level (S E ) to the singlet excited energy level (S G ) Energy transfer In addition, the S1 level (S E ) and T1 level (T E ) are mutually Because of the adjacent energy levels, fluorescence and phosphorescence are clearly distinguishable in the emission spectrum. In some cases, it may be difficult to distinguish between fluorescence and phosphorescence. It may be possible to do so.

[0123] The triplet excitation energy generated in the light-emitting layer 130 is converted into the S1 level of the exciplex through the above-mentioned route A4. The energy transfer from the ion to the S1 level of the guest material (route A6) occurs. Therefore, the light-emitting layer 130 is made of a combination of materials that form an exciplex. By using such a compound, the luminous efficiency of a fluorescent light-emitting device can be improved.

[0124] The compound having a heavy atom used in the above composition is a heavy atom such as Ir, Pt, Os, Ru, or Pd. It is preferable that the compound having a heavy atom is a phosphorescent material. On the other hand, in this configuration example, the phosphorescent material contains an exciplex that acts as an energy donor. Since it is one of the constituent materials, the quantum yield can be either high or low. Directly from the triplet excited energy level of the complex or via the singlet excited energy level It is sufficient that the energy transfer to the singlet excited energy level of the guest material is an allowed transition. As described above, the exciplex composed of phosphorescent materials and the energy transfer from phosphorescent materials to guest materials are The transfer of the energy from the triplet excited energy level of the energy donor to the guest material (energy Energy transfer to the singlet excited energy level of the acceptor is preferred because it is an allowed transition. Therefore, the triplet excited energy of the exciplex can be obtained without going through the process of route A5 in Figure 4C. The energy level of the guest material is increased by route A6. G There is also a route to In route A6, the exciplex is the energy donor and compound 132 is the energy It functions as an energy acceptor.

[0125] In the light-emitting device according to one embodiment of the present invention, the compound 132 has a protecting group on the luminophore. By using this structure, the deck represented by route A7 can be obtained as described above. Suppressing energy transfer via the star mechanism and suppressing the deactivation of triplet excited energy Therefore, a fluorescent light-emitting device with high luminous efficiency can be obtained.

[0126] In one embodiment of the present invention, a phosphorescent material having a five-membered ring skeleton is used. As mentioned above, the energy transfer by the Dexter mechanism represented by route A7 is suppressed. In addition, the carrier in compound 132 can be suppressed from being deactivated. Therefore, it is possible to obtain a fluorescent light-emitting device with high luminous efficiency. It is possible.

[0127] The above-mentioned processes from Route A4 to Route A6 are referred to as ExSET (Exci plex-Singlet Energy Transfer) or ExEF (Exc It is sometimes called iplex-Enhanced Fluorescence. In other words, in the light-emitting layer 130, excitation energy is provided from the exciplex to the fluorescent material. There is.

[0128] <Emitting layer configuration example 3> FIG. 5A shows a case where four kinds of materials are used in the light-emitting layer 130. The optical layer 130 includes a compound 131, a compound 132, a compound 133, and a compound 134. In one embodiment of the present invention, compound 133 has a function capable of converting triplet excitation energy into luminescence. In this configuration example, when compound 133 is a phosphorescent material having a five-membered ring skeleton, Compound 132 is a guest material that exhibits fluorescent emission. 1 is an organic compound that forms an exciplex with compound 134.

[0129] In addition, the compounds 131, 132, and 133 in the light-emitting layer 130 are The energy level correlation of the substance 134 is shown in FIG. 5B. The notations and symbols in FIG. , as follows, and other notations and symbols are the same as those shown in FIG. 2B. ·S C4 : S1 level of compound 134 T C4 :T1 level of compound 134

[0130] In the light-emitting device according to one embodiment of the present invention shown in this configuration example, the chemical compound contained in the light-emitting layer 130 Compound 131 and compound 134 form an exciplex. The S1 level of the exciplex (S E ) and excitation T1 level of the complex (T E ) are adjacent energy levels (Figure 5B Route A 8).

[0131] The exciplexes formed by the above process lose their excitation energy, as described above. The two substances that formed the exciplex then behave as if they were separate substances again.

[0132] Excitation energy levels of exciplexes (S E and T E ) is a compound that forms an exciplex. The S1 levels (S C1 and S C4 ) is lower, It is possible to form an excited state with lower excitation energy. This allows the emission device The driving voltage of the vice 150 can be reduced.

[0133] Here, compound 133 is a phosphorescent material, and intersystem crossing between the singlet and triplet states is Therefore, the singlet excitation energy and triplet excitation energy of the exciplex are Both T and G are rapidly transferred to compound 133 (Route A9). E ≧T C 3. In addition, the triplet excitation energy of compound 133 can be efficiently utilized. The singlet excitation energy of compound 132 can be converted to the 10 ), where: As shown in Figure 5B, T E ≧T C3 ≧S G Then, the excitation energy of compound 133 is This is preferred because it efficiently transfers the excited doublet energy to the guest material, compound 132. Specifically, a tangent line is drawn at the short wavelength side of the phosphorescence spectrum of compound 133, and the The energy of the extrapolated line at wavelength T C3 The absorption spectrum of compound 132 is shown in Fig. 1. A tangent line is drawn at the tail of the long energy or short wavelength side of the fluorescence spectrum, and the wave length of the extrapolated line is The energy of the length is S G When this is done, T C3 ≧S G It is preferable that the formula is: 10 To In this study, compound 133 acts as an energy donor and compound 132 acts as an energy acceptor. It works like this.

[0134] In this case, the combination of Compound 131 and Compound 134 can form an exciplex. Any possible combination is acceptable, but one compound is a compound with hole transport properties and the other is a compound with electron transport properties. More preferably, the compound has a transport property.

[0135] In addition, the combination of compounds 131 and 132 is an example of a combination of materials that efficiently form an exciplex. One HOMO level of the compound 134 is higher than the other HOMO level, and one LUMO level is preferably higher than the other LUMO level.

[0136] In addition, the correlation between the energy levels of compounds 131 and 134 is not limited to that shown in FIG. 5B. That is, the singlet excited energy level (S C1 ) is the compound 134 Singlet excited energy level (S C4 ) may be higher or lower than that of Compound 131. Triplet excited energy level (T C1 ) is the triplet excited energy level (T C4 ) may be higher or lower.

[0137] In the light-emitting device according to one embodiment of the present invention, compound 131 has a π-electron deficient framework. By adopting this structure, the LUMO level of the compound 131 is lowered, and the excitation This is favorable for the formation of an inducing complex.

[0138] In the light-emitting device according to one embodiment of the present invention, the compound 131 has a π-electron-rich framework. By adopting this structure, the HOMO level of the compound 131 is increased, and the excitation This is favorable for the formation of an inducing complex.

[0139] In the light-emitting device according to one embodiment of the present invention, the compound 132 has a protecting group on the luminophore. By using this structure, as described above, Route A 11 De represented by This suppresses the energy transfer via the cluster mechanism and suppresses the deactivation of triplet excitation energy. Therefore, a fluorescent light-emitting device with high luminous efficiency can be obtained.

[0140] In one embodiment of the present invention, a phosphorescent material having a five-membered ring skeleton is used as compound 133. By configuring it as above, route A 11The energy due to the Dexter mechanism is expressed as The compound can suppress the energy transfer and suppress the deactivation of triplet excitation energy. This suppresses the recombination of carriers at 132. This results in a highly efficient fluorescence emission. An optical device can be obtained.

[0141] In addition, the above-mentioned processes of routes A8 and A9 are referred to as ExTET (Exc iplex-Triplet Energy Transfer) In other words, the light-emitting layer 130 is formed by the excitation energy being transferred from the exciplex to the compound 133. Therefore, in this configuration example, a fluorescent material having a protecting group in the light-emitting layer that can utilize ExTET is used. It can be said that the composition is a mixture of materials.

[0142] <Emitting layer configuration example 4> In this configuration example, a material having TADF properties is added to the compound 134 described in the above-mentioned configuration example 3 of the light-emitting layer. We will explain the case where a fee is used.

[0143] FIG. 5C shows a case where four kinds of materials are used in the light-emitting layer 130. The optical layer 130 includes a compound 131, a compound 132, a compound 133, and a compound 134. In one embodiment of the present invention, compound 133 has a function capable of converting triplet excitation energy into luminescence. Compound 132 is a guest material that exhibits fluorescent emission. Compound 131 has the formula: It is an organic compound that forms an exciplex with compound 134. A case where the phosphorescent material has a five-membered ring skeleton will be described.

[0144] Here, since compound 134 is a TADF material, compound 13 does not form an exciplex. 4 converts triplet excitation energy to singlet excitation energy by upconversion. (Fig. 5C Route A 12 The singlet excited energy of compound 134 is Ghee can be rapidly transferred to compound 132 (Figure 5C, Route A). 13 ).child Then, S C4 ≧S G Specifically, the fluorescence spectrum of compound 134 is preferably Draw a tangent line at the base of the short wavelength side, and let the wavelength energy of the extrapolated line be S C4 and the compound The energy of the absorption edge wavelength of 132 in the absorption spectrum or the short wavelength side of the fluorescence spectrum Draw a tangent line at the tail and let the energy of the wavelength of the extrapolated line be S G When this is done, S C4 ≧S G in It is preferable that there is.

[0145] As in the previous example of the configuration of the light-emitting layer, in the light-emitting device according to one embodiment of the present invention, route A in FIG. 8 to Route A 10 Through this, the triplet excitation energy is transferred to the guest material, compound 132. The route that moves and route A in Figure 5C 12 and Route A 13 Move to compound 132 via There are multiple pathways by which triplet excitation energy can be transferred to fluorescent materials. This can further increase the luminous efficiency. 10 In the above, compound 133 is The energy donor, compound 132, acts as an energy acceptor. ToA 13 In the formula, compound 134 is the energy donor and compound 132 is the energy accessor. It functions as a controller.

[0146] In the light-emitting device according to one embodiment of the present invention, the compound 132 has a protecting group on the luminophore. By using this structure, as described above, Route A 11 De represented by This suppresses the energy transfer via the cluster mechanism and suppresses the deactivation of triplet excitation energy. Therefore, a fluorescent light-emitting device with high luminous efficiency can be obtained.

[0147] In one embodiment of the present invention, a phosphorescent material having a five-membered ring skeleton is used as compound 133. By configuring it as above, route A 11 The energy due to the Dexter mechanism is expressed as The compound can suppress the energy transfer and suppress the deactivation of triplet excitation energy. This suppresses the recombination of carriers at 132. This results in a highly efficient fluorescence emission. An optical device can be obtained.

[0148] <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 described. The same is true for the exciplex.

[0149] <Förster mechanism> In the Förster mechanism, the 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 resonance phenomenon of the excitation current, and the first material The first material is in the ground state, and the second material in the ground state is in the excited state. The rate constant of the mechanism, kh*→g is shown in Equation (1).

[0150]

number

[0151] 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 a 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 stands for 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.

[0152] <Dexter System> In the Dexter mechanism, the first and second materials overlap at a certain contact distance. Through the exchange of electrons from the first material in an excited state with those from the second material in the ground state, Energy transfer occurs. The rate constant for the Dexter mechanism is k h*→g is shown in formula (2). vinegar.

[0153]

number

[0154] In formula (2), h is the Planck constant, and K is a constant with the dimension of energy. where ν is the frequency and f' is the h (ν) is the normalized emission spectrum of the first material (When discussing energy transfer from a singlet excited state, the fluorescence spectrum and the triplet excited state are used.) When discussing energy transfer from the nucleophilic state, it represents the phosphorescence spectrum, and ε' 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.

[0155] Here, the energy transfer efficiency from the first material to the second material, φ ET is expressed as formula (3). It will be done. r We discuss the emission process of the first material (energy transfer from the singlet excited state). The rate constants are expressed as follows: fluorescence in the case of a compound that is a triplet excited state, and phosphorescence in the case of a compound that is a triplet excited state. S, k n represents the rate constant of non-radiative processes (thermal deactivation and intersystem crossing) in the second material, and τ is the actual represents the lifetime of the excited state of the first material that is measured.

[0156]

number

[0157] From equation (3), the energy transfer efficiency φ ET To increase the rate of energy transfer, Degree constant k h*→g By increasing the other competing rate constants k r +k n (=1 / τ) is relatively It turns out that the smaller it is, the better.

[0158] <Concept for improving 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 does not depend on 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.

[0159] In addition, 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. In addition, it is preferable that the molar extinction coefficient of the second material is also high. This means that the emission spectrum of the first material is 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 In the second material, the molar extinction coefficient associated with the triplet excited state is negligible. Therefore, triplet excitation from the excited state of the first material to the excited state of 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.

[0160] In addition, the rate of energy transfer by the Förster mechanism is given by equation (1) It is inversely proportional to the sixth power of the intermolecular distance R of the material. Also, as mentioned above, when R is 1 nm or less, Therefore, the energy transfer by the Dexter mechanism is dominant. In order to suppress the energy transfer and increase the rate of energy transfer by the Förster mechanism, The distance between the atoms is preferably 1 nm or more and 10 nm or less. Therefore, the above-mentioned protecting groups are too bulky. Therefore, the number of carbon atoms constituting the protecting group is preferably 3 or more and 10 or less.

[0161] 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 when discussing energy transfer from triplet excited states. in the case of phosphorescence spectrum) and the absorption spectrum of the second material (singlet ground state to singlet excited state) It can be seen that it is better to have a larger overlap with the absorption corresponding to the transition to the The efficiency of energy transfer is optimized by matching the emission spectrum of the first material with the longest wavelength of the second material. This is achieved by overlapping with the absorption band appearing on the long side.

[0162] In addition, by substituting formula (2) into formula (3), the energy transfer in the Dexter mechanism is Efficiency φ ET It can be seen that depends on τ. The Dexter mechanism is an energy mechanism based on electron exchange. Since this 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.

[0163] In the light-emitting device according to 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 material is low. It is preferred that the efficiency of energy transfer from one 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

[0164] As already mentioned, the efficiency of energy transfer in the Förster mechanism is On the other hand, the efficiency of energy transfer in the Dexter mechanism does not depend on the lifetime τ of the excited state of the material. depends on the excitation lifetime τ of the first material and reduces the efficiency of energy transfer in the Dexter mechanism. In order to reduce the excitation wavelength, it is preferable that the excitation lifetime τ of the first material is short.

[0165] 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 photocatalyst mechanism depends on the emission quantum yield of the energy donor. The triplet excited state can be converted to light emission, such as in photoactive materials, exciplexes, or TADF materials. The first material transfers its excitation energy to the second material via the Förster mechanism. On the other hand, according to the configuration of one embodiment of the present invention, the first material (exciplex or TADF promotes reverse intersystem crossing from a triplet excited state of the first material to a singlet excited state, The excited lifetime τ of the doublet excited state can be shortened. The transition from the triplet excited state of the phosphorescent material to the singlet ground state of the exciplex is promoted. As a result, the excited lifetime τ of the triplet excited state of the first material can be shortened. Dextran from the triplet excited state of the first material to the triplet excited state of the fluorescent material (second material) This can reduce the efficiency of energy transfer in the reaction mechanism.

[0166] In the light-emitting device according to one embodiment of the present invention, as described above, the second material has a protecting group. To achieve this, the intermolecular distance between the first and second materials is increased. Therefore, in the light-emitting device according to one embodiment of the present invention, the first material contains triplet excited electrons. A material having a function of converting energy into light emission is placed on the second material, which is a fluorescent material having a protecting group. By using the Dexter mechanism, the efficiency of energy transfer can be reduced. As a result, non-radiative deactivation of triplet excitation energy in the light-emitting layer 130 can be suppressed. As a result, a light emitting device with high luminous efficiency can be provided.

[0167] <Material> Next, the components of the light-emitting device according to one embodiment of the present invention will be described in detail below. cormorant.

[0168] <Light-emitting layer> The materials that can be used for the light-emitting layer 130 of the present invention are described below. The light-emitting layer of the light-emitting device according to one embodiment has a function of converting triplet excitation energy into light emission. The energy acceptor has a protective group on the luminophore, and the energy donor has a protective group on the luminophore. Materials that have the function of converting excitation energy into light emission include TADF materials and phosphorescent materials. Materials include:

[0169] The luminophore contained in compound 132 that functions as an energy acceptor is, for example, Phenothrenes, stilbenes, acridones, phenoxazines, phenothiazines In particular, naphthalene skeleton, anthracene skeleton, fluorene skeleton, chlorine skeleton, etc. Ricenes, triphenylenes, tetracenes, pyrenes, perylenes, kumaris Fluorescent compounds with a quinacridone skeleton, a quinacridone skeleton, or a naphthobisbenzofuran skeleton have a high fluorescence intensity. This is preferred because it has a high molecular weight yield.

[0170] 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 with 3 to 10 carbon atoms, trialkyl groups with 3 to 12 carbon atoms Alkylsilyl groups are preferred.

[0171] Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a pentyl group, and the like. Examples of the branched chain alkyl group include aryl and hexyl groups, and the branched chain alkyl group having 3 to 10 carbon atoms is described below. These are particularly preferred. However, the alkyl group is not limited to these.

[0172] 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 of the alkyl group 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 group, cyclopentyl group, cyclohexyl group, cycloheptyl group, 8,9, cycloalkyl groups having 5 to 7 carbon atoms, such as 10-trinorbornanyl groups, and phenyl Examples of the aryl groups include aryl groups having 6 to 12 carbon atoms such as a naphthyl group and a biphenyl group.

[0173] Examples of branched alkyl groups having 3 to 10 carbon atoms include an isopropyl group and a sec-butyl group. , 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.

[0174] Examples of the trialkylsilyl group having 3 to 12 carbon atoms include a trimethylsilyl group, a triethylsilyl group, and a Examples of the trialkylsilyl include a trialkylsilyl group and a tert-butyldimethylsilyl group. The groups are not limited to these.

[0175] The molecular structure of the energy acceptor is a luminophore and two or more diaryla. 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, in this case, the effect of suppressing energy transfer by the Dexter mechanism is large. 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.

[0176] In addition, by binding two or more amino groups to the luminophore, it is possible to adjust the emission color and the amount of A fluorescent material with a high molecular yield can be obtained. In addition, the amino group is symmetrical with respect to the luminophore. By using this structure, it is possible to obtain a fluorescent material having a high quantum yield. This can be a fee.

[0177] In addition, instead of directly introducing a protecting group into the luminophore, the aryl group of the diarylamine is By adopting this structure, the protective group is introduced so as to cover the luminophore. This allows the distance between the host material and the luminophore to 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 photophore.

[0178] In addition, as shown in FIG. 3B, 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 has multiple protecting groups. At least one of the atoms constituting the group is on the other side of the fused aromatic ring or the fused heteroaromatic ring. The preferred configuration is to have the sensor located directly above the sensor. The specific methods for this are as follows: That is, the luminophore, condensed aromatic ring or condensed heteroaromatic ring, is composed of two or more diphenyl and each of the phenyl groups in the two or more diphenylamino groups is independently , and has protecting groups at the 3- and 5-positions.

[0179] With this structure, as shown in FIG. 3B, the 3- or 5-position of the phenyl group The protective group is arranged so that it is located directly above the condensed aromatic ring or condensed heteroaromatic ring which is the luminophore. As a result, the above and below the plane of the fused aromatic ring or the fused heteroaromatic ring can be It can efficiently cover the area and suppress dexter movement.

[0180] The energy acceptor as described above is represented by the following general formula (G1) or (G2 ) can be suitably used.

[0181] [ka]

[0182] In the general formulae (G1) and (G2), A is a substituted or unsubstituted fused aromatic ring having 10 to 30 carbon atoms. Ar represents an aromatic ring or a substituted or unsubstituted condensed 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 each independently represents a branched alkyl group having 3 to 10 carbon atoms, or unsubstituted cycloalkyl group having 3 to 10 carbon atoms; R represents one of the alkylsilyl groups; 1 ~R 10 are each 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 from 3 to 12 carbon atoms;

[0183] 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 is preferably a methyl group, an ethyl group, or the like. , propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert -C1 to C7 alkyl groups 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 the aryl groups include aryl groups having 6 to 12 carbon atoms such as the group.

[0184] In the general formula (G1), 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.

[0185] 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 so as to cover the luminophore. Therefore, it is possible to suppress the energy transfer by the Dexter mechanism. It may have a protecting group that is directly bonded to the luminophore.

[0186] The energy acceptor is represented by the following general formula (G3) or (G4): Organic compounds having such a property can be suitably used.

[0187] [ka]

[0188] 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 condensed heteroaromatic ring having 10 to 30 carbon atoms; 1 ~X 12 each independently represents 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 groups.

[0189] It is also preferred 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, so that 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 following general formulae (G3) and (G As shown in 4), the two protecting groups are bonded at the meta position to the phenylene group. This structure allows the luminophore to be covered efficiently, and thus the dextran The organic compound represented by the general formula (G3) can suppress the energy transfer by the electron transport mechanism. An example of a compound is the above-mentioned 2tBu-mmtBuDPhA2Anth. That is, in one embodiment of the present invention, (G3) is a particularly preferred example.

[0190] As the energy acceptor, an organic compound represented by the following general formula (G5) is used. It can be suitably used.

[0191] [ka]

[0192] In general formula (G5), X 1 ~X 8 each independently represents a branched chain alkyl group having 3 to 10 carbon atoms. alkyl group, substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, 3 or more carbon atoms R represents any one of 10 or less trialkylsilyl groups; 11 ~R 18 are independent hydrogen, branched alkyl group having 3 to 10 carbon atoms, substituted or unsubstituted alkyl group having 3 or less carbon atoms Cycloalkyl groups having 10 or less carbon atoms, trialkylsilyl groups having 3 to 10 carbon atoms, or an unsubstituted aryl group having 6 to 25 carbon atoms.

[0193] Examples of the aryl group having 6 to 25 carbon atoms include a phenyl group, a naphthyl group, a biphenyl group, and the like. Examples of the fluorenyl group include fluorenyl groups, spirofluorenyl groups, and the like. The aryl group having 5 or less carbon atoms is not limited to the above. In addition, when the aryl group has a substituent, the above-mentioned alkyl group having 1 to 10 carbon atoms, and the branched alkyl group having 3 to 10 carbon atoms. , a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, Examples of the trialkylsilyl group include the following:

[0194] Anthracene compounds have high luminescence quantum yields and small luminophore surface area, so the protective groups prevent the It is possible to efficiently cover the upper and lower sides of the anthracene surface. An example of such an organic compound is the above-mentioned 2tBu-mmtBuDPhA2Anth. can be.

[0195] An example of the compound 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 (249). The compounds represented by the structural formulas (102) to (105) are not limited to these. The compounds shown in (200) to (249) are guest materials for a light-emitting device according to one embodiment of the present invention. However, the guest material is not limited to these.

[0196] [ka]

[0197] [ka]

[0198] [ka]

[0199]

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[0209] In addition, one of the materials that can be suitably used as a guest material in the light-emitting device of one embodiment of the present invention is Examples are shown in structural formulas (100) and (101). Note that the guest material is not limited to these. stomach.

[0210] [ka]

[0211] As the compound 133, a phosphorescent material having a five-membered ring skeleton can be used. The phosphorescent material may be an organometallic complex of iridium, rhodium, or platinum; Metal complexes include platinum complexes with porphyrin ligands and organic iridium complexes. Among them, for example, organic iridium complexes such as iridium orthometal complexes are The orthometalating ligand is preferably a pyrrole ligand, a pyrazole ligand, or a 4H -Triazole ligand, 1H-triazole ligand, imidazole ligand, benzimidazoline ligand In this case, compound 133 ( Phosphorescent material) is triplet MLCT (Metal to Ligand Charge Tr The emission peak of compound 133 is the absorption band of the ansfer transition. Compound 133, which overlaps with the absorption band on the longest wavelength side (lowest energy side) of (fluorescent material); It is preferable to select compound 132 (fluorescent material), which increases the luminous efficiency. Compound 133 is a phosphorescent material. Even in this case, it is acceptable to form an exciplex with compound 131. The phosphorescent material does not need to emit light at room temperature, but it is sufficient if it can emit light at room temperature when it forms an exciplex. In this case, for example, tris[2-(1H-pyrazol-1-yl-κN2]phenyl Iridium(III) (abbreviation: Ir(ppz)3) is used as a phosphorescent material. There can be.

[0212] Examples of substances having a blue or green emission peak include tris{2-[5-(2 -methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazo {3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: Ir(mpp tz-dmp)3), tris(5-methyl-3,4-diphenyl-4H-1,2,4-tris( riazolate)iridium(III) (abbreviation: Ir(Mptz)3), tris[4-(3- Biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato]i Iridium(III) (abbreviation: Ir(iPrptz-3b)3), tris[3-(5-biphenyl] (phenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazolato]irid Ir(iPr5btz)3, tris{2-[4-(4-cyano -2,6-diisobutylphenyl)-5-(2-methylphenyl)-4H-1,2,4- Triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: Ir (mpptz-diBuCNp)3), tris{2-[5-(2-methylphenyl)-4 -(2,6-diisopropylphenyl)-4H-1,2,4-triazol-3-yl- κN2]phenyl-κC}iridium(III) (abbreviation: Ir(mptz-diPrp )3) and organometallic iridium complexes with a 4H-triazole skeleton, such as tris[3 -Methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazola Tris(1-methyl)iridium(III) (abbreviation: Ir(Mptz1-mp)3) -5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) ) (abbreviation: Ir(Prptz1-Me)3) iridium complexes and fac-tris[1-(2,6-diisopropylphenyl)- 2-phenyl-1H-imidazole]iridium(III) (abbreviation: Ir(iPrpmi )3), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f ]phenanthridinato]iridium(III) (abbreviation: Ir(dmpimpt-Me)3 ), and tris{2-[1-( 4-Cyano-2,6-diisobutylphenyl)-1H-benzimidazol-2-yl- κN3]phenyl-κC}iridium(III) (abbreviation: Ir(pbi-diBuCNp )3), (OC-6-22)-tris{2-[1-(2,6-diisobutylphenyl)- 1H-Benzimidazol-2-yl-κN3]phenyl-κC}iridium(III) (abbreviation: Ir(pbi-diBup)3) Metallic iridium complexes and bis{2-[1-(2,6-diisobutylphenyl)-1H-na 1,2-d]imidazol-2-yl-κN3]phenyl-κC}[2-(4-methylphenyl) 5-phenyl-2-pyridyl-κN2)phenyl-κC]iridium(III)( Abbreviation: Ir(pni-diBup)2(mdppy)), Tris{2-[1-(2,6- Diisobutylphenyl)-1H-naphtho[1,2-d]imidazol-2-yl-κN3 ]phenyl-κC}iridium(III) (abbreviation: Ir(pni-diBup)3) Examples of the organometallic iridium complexes having a naphthoimidazole skeleton include the above-mentioned However, 4H-triazole skeleton, 1H-triazole skeleton, imidazole skeleton, benzo Nitrogen-containing five-membered heterocyclic skeletons such as zoimidazole skeleton and naphthoimidazole skeleton Organic metal iridium complexes have high triplet excitation energy and are highly reliable and have excellent luminescence efficiency. In addition, 2,3,7,8,12,13,17,18-octaethyl Platinum complexes such as -21H,23H-porphyrin platinum(II) (abbreviation: PtOEP) , Tris[1-(2-thenoyl)-3,3,3-trifluoroacetonate](Monofena (TTA)3(Phen) Rare earth metal complexes may also be used.

[0213] Compound 134 may be, for example, a TADF material. It is preferable that the energy difference between the T1 level and the T1 level is small, specifically, greater than 0 eV. It is less than 0.2 eV.

[0214] Compound 134 has a skeleton having a hole transporting property and a skeleton having an electron transporting property. Alternatively, compound 134 may be a compound having a π-electron rich backbone or an aromatic amine backbone and It is preferable that the π-electron-deficient skeleton is provided. In this way, the donor-accessor structure is formed in the molecule. In addition, the donor and activator functions in the compound 134 molecule are easily formed. The structure is such that the electron-transporting skeleton and the hole-transporting skeleton are both strong. Alternatively, it is preferable that the structure has a π-electron-rich skeleton or an aromatic structure. It is preferable that the aromatic amine skeleton and the π-electron deficient skeleton are directly bonded to each other. By strengthening both the donor and acceptor properties of , the HOMO of compound 134 was improved. The overlap between the region where the molecular orbitals are distributed and the region where the molecular orbitals in the LUMO are distributed is reduced. The singlet and triplet excited energy levels of compound 134 can be calculated. It is possible to reduce the energy difference between the triplet excited states of compound 134 and This allows the energy levels to be kept at high energies.

[0215] When a TADF material is composed of one type of material, for example, the following material can be used: can.

[0216] 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. Phosphorus-tin fluoride complex (SnF2(Proto IX)), mesoporphyrin-sulfur fluoride SnF2(Meso IX) and hematoporphyrin-tin fluoride complex (SnF 2 (Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (SnF2(Copro III-4Me)), Octaethylporphyrin-Fluoride tin complex (SnF2(OEP)), etioporphyrin-tin fluoride complex (SnF2(Et io I)), octaethylporphyrin-platinum chloride complex (PtCl2OEP), etc. can be done.

[0217] [ka]

[0218] In addition, as a thermally activated delayed fluorescent material composed of one kind of material, Heterocyclic compounds having a π-electron deficient skeleton can also be used. phenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazole 2-{4-[3 -(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl] Phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn) , 2-[4-(10H-phenoxazin-10-yl)phenyl]-4,6-diphenyl -1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4-(5-phenyl-5, 10-Dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4 -Triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acrylamide 4-(4H-xanthen-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN), 9,9-Dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviation: DMA C-DPS), 10-phenyl-10H,10'H-spiro[acridine-9,9'-a ACRSA, 4-(9'-phenyl-3,3'- Bis-9H-carbazol-9-yl)benzofuro[3,2-d]pyrimidine (abbreviation: 4P CCzBfpm), 4-[4-(9'-phenyl-3,3'-bi-9H-carbazole- 9-yl)phenyl]benzofuro[3,2-d]pyrimidine (abbreviation: 4PCCzPBfp m), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl ]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn- 02) and the like, which have either or both of a π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring. The heterocyclic compounds include π-electron-rich heteroaromatic rings and π-electron-deficient heteroaromatic rings. Since it has a heteroaromatic ring, it has high electron transport properties and hole transport properties, which is preferable. Among the skeletons that have a molecule-deficient heteroaromatic ring, the pyridine skeleton, the diazine skeleton (pyrimidine skeleton , pyrazine skeleton, pyridazine skeleton), and triazine skeleton are stable and reliable. In particular, benzofuropyrimidine skeleton, benzothienopyrimidine skeleton, benzofuropyrimidine skeleton, The thienopyrazine and benzothienopyrazine skeletons have high acceptor properties and good reliability. Among the skeletons having a π-electron-rich heteroaromatic ring, acridine skeleton, fluoro skeleton, etc. are preferred. Phenoxazine skeleton, phenothiazine skeleton, furan skeleton, thiophene skeleton, and pyrrole skeleton It is preferable that the structure has at least one of the above skeletons because it is stable and reliable. 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 carbamate skeleton. azole skeleton, bicarbazole skeleton, 3-(9-phenyl-9H-carbazol-3-yl A π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring are particularly preferred. The substance in which the aromatic heterocycle is directly bonded to the π-electron-rich heterocycle exhibits the donor property of the π-electron-poor heterocycle. The acceptor properties of the toe-shaped heteroaromatic rings are both strong, and the levels of the singlet excited state and the triplet excited state are both strong. This is particularly preferred because the difference in the levels is small. An aromatic ring to which an electron-withdrawing group such as a cyano group is bonded may also be used. As the π-electron deficient alkyl group, an aromatic amine skeleton, a phenazine skeleton, etc. can be used. As the type skeleton, xanthene skeleton, thioxanthene skeleton, dioxide skeleton, oxadiazo skeleton, azole skeleton, triazole skeleton, imidazole skeleton, anthraquinone skeleton, phenylborane boron-containing skeletons such as boranethrene, benzonitrile, cyanobenzene, etc. Or aromatic rings or heteroaromatic rings with cyano groups, carbonyl skeletons such as benzophenone, phosphatidylcholine, etc. A fin oxide skeleton, a sulfone skeleton, etc. can be used. A π-electron deficient skeleton is used in place of at least one of the heteroaromatic ring and the π-electron rich heteroaromatic ring. and π-electron rich frameworks can be used.

[0219] [ka]

[0220] When compound 134 does not have the function of converting triplet excitons into luminescence, it is converted to compound 131. Compound 133 or a combination of compounds 131 and 134 can form an exciplex with each other. However, there is no particular limitation to the combination. It is preferable that the compound has a function of transporting holes.

[0221] 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.

[0222] In addition, the following hole transporting materials and electron transporting materials can be used.

[0223] As the hole transporting material, a material having a higher hole transporting property than an electron transporting property can be used. ×10 -6 cm 2 It is preferable that the material has a hole mobility of 1 / Vs or more. The compounds are made using aromatic amines, carbazole derivatives, aromatic hydrocarbons, stilbene derivatives, etc. The hole transporting material may be a polymer compound.

[0224] As examples of materials with high hole transport properties, aromatic amine compounds include 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 Examples include]-N-phenylamino]benzene (abbreviation: DPA3B).

[0225] 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) etc. can be mentioned.

[0226] Another example of a carbazole derivative is 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 and the like can be used.

[0227] As the aromatic hydrocarbon, for example, 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 DPPA, 2-tert-butyl-9,10-bis(4-phenylphenyl) 9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDBA), Helical (abbreviation: DNA), 9,10-diphenylanthracene (abbreviation: 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 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, coro Years and years 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.

[0228] 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.

[0229] In addition, poly(N-vinylcarbazole) (abbreviation: PVK) and poly(4-vinyltriphenylphosphine) 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 Poly(phenyl)benzidine (abbreviation: Poly-TPD) can also be used. can.

[0230] As a material with high hole transport properties, for example, 4,4'-bis[N-(1-naphthyl )-N-phenylamino]biphenyl (abbreviation: NPB or α-NPD) and N,N'-biphenyl S(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-naphthalene 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 mBPAFLP, N-(9,9-dimethyl-9H-fluorene-2- 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-fluorenyl) Fluoren-7-yl)diphenylamine (abbreviation: DPNF), 2-[N-(4-diphenyl N-phenylaminophenyl)spiro-9,9'-bifluorene (abbreviation: D PASF), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl) PCBA1BP, 4,4'-diphenyl-4''-(9-phenyl) (phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP ), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)- Triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''- (9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBN BB), 4-phenyldiphenyl-(9-phenyl-9H-carbazol-3-yl)a 1BP, 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-yl) N-(4-biphenyl)benzene-1,3,5-triamine (abbreviation: PCA3B) -N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazone PCBiF, N-(1,1'-biphenyl-4-yl) -N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-di Methyl-9H-fluoren-2-amine (abbreviation: PCBBiF), 9,9-dimethyl-N -Phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]- Fluorene-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-yl) N-(4-phenyl)phenylaniline (abbreviation: YGA1BP), N'-bis[4-(carbazol-9-yl)phenyl]-N,N'-diphenyl-9, Aromatic amination of 9-dimethylfluorene-2,7-diamine (abbreviation: YGA2F) etc. Compounds such as 3-[4-(1-naphthyl)-phenyl]-9-phenyl- Phenyl-9H-carbazole (abbreviation: PCPN), 3-[4-(9-phenanthryl)- Phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPPn), 3,3'-bis (9-phenyl-9H-carbazole) (abbreviation: PCCP), 1,3-bis(N-carbazole) 3,6-bis(3,5-diphenylphenyl)-9 -Phenylcarbazole (abbreviation: CzTP), 4-{3-[3-(9-phenyl-9H- Fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLB i-II), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) oran) (abbreviation: DBF3P-II), 1,3,5-tri(dibenzothiophene-4-yl )-benzene (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl (abbreviation: DBTFL) P-III), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]- 6-Phenyldibenzothiophene (abbreviation: DBTFLP-IV), 4-[3-(triphenyl (2-phenyl-2-yl)dibenzothiophene (abbreviation: mDBTPTp-II) Amine compounds, carbazole compounds, thiophene compounds, furan compounds, fluorene compounds Compounds such as triphenylene compounds and phenanthrene compounds can be used. The substances that were detected were mainly 1×10 -6 cm 2 / Vs or more. Any other substance may be used as long as it has a higher hole transporting property than an electron transporting property.

[0231] As the electron transport material, a material having a higher electron transporting property than a hole transporting property can be used. ×10 -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 easy to absorb (materials with electron transport properties). π-electron deficient heteroaromatic compounds and metal complexes can be used. Ligands containing benzoquinoline, oxazole, or thiazole ligands metal complexes, oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, Examples of the derivatives include pyridine derivatives, bipyridine derivatives, and pyrimidine derivatives.

[0232] For example, tris(8-quinolinolato)aluminum(III) (abbreviation: Alq), tri Bis(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), BeBq2 ), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum ( III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq) 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]be 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-triphenyl TAZ (abbreviation: TAZ), 2,2',2''-(1,3,5-benzenetriyl)tris( (1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(diphenyl 1-phenyl-1H-benzoimidazole (abbreviation) : mDBTBIm-II), bathophenanthroline (abbreviation: BPhen), 2,9-bis (Naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: Heterocyclic compounds such as NBPhen, bathocuproine (BCP), and 2-[3- (Dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl 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 quinoxaline (abbreviation: 7mDBTPDBq-II) and 6-[3-( Dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6 mDBTPDBq-II), 4,6-bis[3-(phenanthren-9-yl)phenyl ]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothie 4,6-bis[phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2 Heterocyclic compounds with diazine skeletons such as 2-{4-[3-(N-phenyl- 9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6 -Diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn) and other triazine skeletons Heterocyclic compounds with cyclic rings and 3,5-bis[3-(9H-carbazol-9-yl)phenyl] 3-(3-pyridyl)pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl) Heterocyclic compounds having a pyridine skeleton, such as phenylbenzene (abbreviation: TmPyPB), 4,4'-Bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzO Heteroaromatic compounds such as poly(2,5-pyridinediamine) can also be used. Poly[(9,9-dihexylfluorene-2,7-diyl)-c o-(pyridine-3,5-diyl)] (abbreviation: PF-Py), poly[(9,9-dioctyl Fluorene-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl) Polymer compounds such as PF-BPy can also be used. The quality is mainly 1×10 -6 cm 2 / Vs or higher. Substances other than those mentioned above may be used as long as they have a higher electron transporting property than the above-mentioned substances.

[0233] Compound 134 is preferably a combination capable of forming an exciplex with compound 131. Specifically, the hole transporting materials and electron transporting materials shown above can be used. In this case, the emission peak of the exciplex formed by Compound 131 and Compound 134 is The longest wavelength (lowest energy) absorption band of 133 (a phosphorescent material with a five-membered ring structure) Compounds 131, 134, and 133 (a phosphorus compound having a five-membered ring skeleton) are overlapping. This allows the production of a light-emitting device with dramatically improved luminous efficiency. It can be a vice.

[0234] The light-emitting layer 130 may be formed 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 a hole transporting property is used as a host material for the first light-emitting layer, and a substance having a hole transporting property 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 insulating film.

[0235] In the light-emitting layer 130, the compounds 131, 132, 133 and 134 are In this case, the compound 131 and the compound 134 may have a material other than the compound 135. In order for compound 133 (or compound 134) to efficiently form an exciplex, compound 13 The HOMO level of either compound 1 or compound 133 (or compound 134) is The material in the light-emitting layer 130 has the highest HOMO level, and the other material has the highest LUMO level. It is preferable that the LUMO level of the cation is the lowest among the cations. This makes it possible to suppress the reaction of compound 131 and compound 135 forming an exciplex. do.

[0236] For example, Compound 131 has a hole transporting property, and Compound 133 (or Compound 134) has an electron transporting property. In the case of the electron transport property, the HOMO level of compound 131 is the same as that of compound 133. and the HOMO level of compound 135 is preferably higher than the LUMO level of compound 133. It is preferable that the LUMO level is lower than that of compound 131 and that of compound 135. In this case, the LUMO level of compound 135 is higher than that of compound 131. The HOMO level of compound 135 may be lower than the HOMO level of compound 133. It can be high or low.

[0237] 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 Bis(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), 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 ), 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 -benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TP BI), Bathophenanthroline (abbreviation: BPhen), Bathocuproine (abbreviation: BCP ), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl] -9H-carbazole (abbreviation: CO11), and other heterocyclic compounds, such as 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 Specifically, 9,10-diphenylanthracene (abbreviation: DPAn th), N,N-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl ]-9H-Carbazole-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] PCAPA, N,9-diphenyl -N-{4-[4-(10-phenyl-9-anthryl)phenyl]phenyl}-9H- Carbazole-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 9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole ( 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'- Diphenylphenanthrene (DPNS), 9,9'-(stilbene-4,4'-di 1,3,5-tri(1-pyrenyl)benzoate (abbreviation: DPNS2), Among these and other known substances, Therefore, the energy gap is larger than that of Compound 131 and Compound 132. One or more substances having a gap may be selected and used.

[0238] The electrode 101 and the electrode 102 have a 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. The metal can be aluminum (Al) as a typical example. , 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 (abbreviation: ITSO), indium zinc oxide (Indium Z inc Oxide), tungsten and zinc-containing indium oxide, etc. As the conductive compound, an inorganic carbon-based material such as graphene may be used. As described above, electrodes 101 and 10 are formed by stacking multiple layers of these materials. 2 or both may be formed.

[0239] 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. The conductive material has a function of transmitting light. The transmittance is 40% or more and 100% or less, preferably 60% or more and 100% or less, and the resistance Resistance is 1×10 -2 Materials with a conductivity of Ω cm or less are also suitable. The electrode is made of a conductive material having a function of transmitting light and a function of reflecting light. The conductive material has a visible light reflectance of 20% or more and 80% or less, preferably 4 0% to 70% and its 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 that is thick enough to transmit visible light (for example, 1 nm to 10 nm). Either or both of the electrode 101 and the electrode 102 may be formed.

[0240] In this specification and the like, the electrode having a function of transmitting light includes an electrode having a function of transmitting visible light. Any material having both the function and electrical conductivity may be used, and examples thereof include ITO as mentioned above. 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 including 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.

[0241] 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.

[0242] <Hole injection layer> The hole injection layer 111 is configured to inject 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. It is formed by phthalocyanine derivatives or aromatic amines. Transition metal oxides and 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 It is also possible to use self-doped polythiophenes, such as poly(ethylenediamine). Representative examples include poly(oxythiophene) / poly(styrenesulfonic acid).

[0243] The hole injection layer 111 is made of a compound of a hole transporting material and a material that has an electron accepting property. Alternatively, a layer containing a material exhibiting electron accepting properties and a layer containing a positive electrode may be used. A stack of layers containing hole transporting materials may also be used. It is possible to give and receive electric charges in the presence of a magnetic field. Materials that exhibit electron-accepting properties include quinodimethane. Organic acceptors such as aryl, chloranil, 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-naphthyl Electron-withdrawing groups such as fluoro groups, e.g., dimethylmethane (abbreviation: F6-TCNNQ) In particular, compounds having multiple groups such as HAT-CN can be mentioned. Compounds in which an electron-withdrawing group is bonded to a condensed aromatic ring having multiple atomic atoms are thermally stable. It is also preferable that the aryl group 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 a very high electron-accepting property. Specifically, α,α' ,α''-1,2,3-cyclopropanetriylidenetris[4-cyano-2,3,5, 6-Tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclo Propane triylidene tris[2,6-dichloro-3,5-difluoro-4-(trifluoro (O-methyl)benzeneacetonitrile], α,α',α''-1,2,3-cyclopropane Tris[2,3,4,5,6-pentafluorobenzeneacetonitrile] In addition, transition metal oxides, for example, oxides of metals in 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.

[0244] As the hole transporting material, a material having a higher hole transporting property than an electron transporting property can be used. ×10 -6 cm 2 It is preferable that the material has a hole mobility of 1 / Vs or more. The aromatic amines and the like 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.

[0245] Examples of aromatic hydrocarbons include 2-tert-butyl-9,10-di(2-naphthyl) 2-tert-butyl-9,10-di(1 -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 2,3,6,7-tetramethyl-9,10-di(2-naphthyl)anthracene 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-tetra (tert-butyl)perylene, etc. In addition, pentacene, coronene, etc. can also be used. Thus, 1×10 -6 cm 2 / Vs or more It is more preferable to use aromatic hydrocarbons having 14 or more carbon atoms and 42 or less carbon atoms.

[0246] 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.

[0247] In addition, poly(N-vinylcarbazole) (abbreviation: PVK) and poly(4-vinyltriphenylphosphine) 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 Poly(phenyl)benzidine (abbreviation: Poly-TPD) can also be used. can.

[0248] <Hole transport layer> The hole transport layer 112 is a layer containing a hole transporting 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 a HOMO level similar to that of the hole injection layer 111. It is preferable that the HOMO level of each of the aryl groups is the same as or close to the HOMO level of each of the aryl groups.

[0249] As the hole transport material, the material exemplified as the material of the hole injection layer 111 is used. Also, 1×10 -6 cm 2 The material has a hole mobility of ≥ 100 / Vs. 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 having a high hole transporting property may be a single layer or a layer containing the above-mentioned substance. Two or more layers may be laminated.

[0250] ≪Electron transport layer≫ The electron transport layer 118 is connected to the other of the pair of electrodes (electrode 101 or The material has a function of transporting electrons injected from the electrode 102 to the light-emitting layer 130. A material with a higher electron transport capacity than holes can be used as the -6 cm 2 It is preferable that the material has an electron mobility of 100 / Vs or more. As materials with electron transport properties, π-electron-deficient compounds such as nitrogen-containing heteroaromatic compounds are Heteroaromatics and metal complexes can be used. Specifically, the light-emitting layer 130 can be 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 known. 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 100 or more. Other substances than those mentioned above may be used as the electron transport layer as long as they have high electron transport properties. The transport layer 118 may be a single layer or a laminate of two or more layers made of the above-mentioned materials.

[0251] 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 a substance 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. Suppression of problems caused by electron tunneling through layers (e.g., reduced device life) It has a significant effect on the system.

[0252] ≪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 above-mentioned electron transporting material and the corresponding electron A composite material of a material exhibiting electron donating properties can also be used. Examples of the metal include Group 1 metals, Group 2 metals, and oxides thereof. 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 fluorine (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 ruthenium. The injection layer 119 may be made of a material that can be used in the electron transport layer 118 .

[0253] In addition, the electron injection layer 119 is made of a composite material obtained by mixing an organic compound and an electron donor. Such composite materials may be made by adding electrons to an organic compound via an electron donor. In this case, the organic compound is It is preferable that the material has excellent transport properties for 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, Magnesium, calcium, erbium, ytterbium, etc. 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 (TTF). It is also possible.

[0254] 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 be made of quantum dots or the like. Inorganic compounds or polymeric compounds (oligomers, dendrimers, polymers, etc.) may be used. stomach.

[0255] The quantum dots are classified into colloidal quantum dots, alloy quantum dots, and core-shell quantum dots. In addition, a group 2 and a group 16, a group 13 and a group 14, and a core type quantum dot may be used. Contains element groups 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 (Ga), Quantum dots containing elements such as Ga, Arsenic, and Aluminum are used. It's fine.

[0256] Examples of liquid media used in wet processes include methyl ethyl ketone, cyclohexane, etc. Ketones such as xanone, fatty acid esters such as ethyl acetate, halogens such as dichlorobenzene Hydrocarbons, aromatics such as toluene, xylene, mesitylene, and cyclohexylbenzene Hydrocarbons, aliphatic hydrocarbons such as cyclohexane, decalin, and dodecane, dimethylformamide, etc. Organic solvents such as dichloromethane (DMF) and dimethyl sulfoxide (DMSO) can be used. Cut.

[0257] Examples of polymer compounds that can be used in the light-emitting layer include poly[2-methoxy]phenylene. [MeH] -PPV), polyphenylenes such as poly(2,5-dioctyl-1,4-phenylenevinylene), Poly(9,9-di-n-octylfluorenyl-2,7 -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. Poly(N-vinylcarbazole) (abbreviation: PVK), Poly(2-vinylnaphthalene), Ri[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (abbreviation: PTA A) or the like polymer compound may be doped with a light-emitting compound and used in the light-emitting layer. As the compound, the above-mentioned luminescent compounds can be used.

[0258] <Substrate> In addition, the light-emitting device according to one aspect of the present invention includes a substrate made of glass, plastic, or the like. The order of fabrication on the substrate may be stacked from the electrode 101 side onwards. Alternatively, they may be laminated in order from the electrode 102 side.

[0259] The substrate on which the light-emitting device according to one embodiment of the present invention can be formed is, for example, glass, Quartz, plastic, or the like can be used. A flexible substrate can also be used. A flexible substrate is a substrate that can be bent (flexible). For example, Examples of suitable substrates include plastic substrates made of carbonate and polyarylate. In addition, a film made of inorganic vapor deposition may be used. Any other material may be used as long as it functions as a support in the manufacturing process. It is sufficient that the protective cover has a function of protecting the light emitting device and the optical device.

[0260] For example, in this specification, it is possible to form a light emitting device using various substrates. The type of substrate is not particularly limited. An example of the substrate is a semiconductor substrate (e.g. Single crystal substrate or silicon substrate), SOI substrate, glass substrate, quartz substrate, plastic substrate , metal substrate, stainless steel substrate, substrate with stainless steel foil, tantalum Tungsten substrate, substrate with tungsten foil, flexible substrate, lamination film, These include cellulose nanofiber (CNF), paper, and base film, which contain fibrous materials. Examples of the glass substrate include barium borosilicate glass and aluminoborosilicate glass. , or soda lime glass. Flexible substrates, lamination films, base films Examples of such materials include polyethylene terephthalate (PET) ), polyethylene naphthalate (PEN), polyethersulfone (PES), polytetrafluoroethylene (PTFE) There are plastics such as tetrafluoroethylene (PTFE). Examples of the resin include acrylic resin. Examples of the resin include polypropylene, polyester, etc. Polyvinyl chloride, polyvinyl fluoride, or polyvinyl chloride. Examples of the material include inorganic materials such as amide, polyimide, aramid, epoxy, inorganic vapor deposition film, and paper.

[0261] In addition, a flexible substrate is used as the substrate, and a light-emitting device is formed directly on the flexible substrate. Alternatively, a release layer may be provided between the substrate and the light emitting device. After completing a part or all of the light-emitting device, it is separated from the substrate and transferred to another substrate. In this case, it is possible to form light-emitting devices on substrates with poor heat resistance or flexible substrates. The above-mentioned peeling layer may be, for example, a tungsten film and a silicon oxide film. It uses a laminated structure of inorganic films, or a structure in which a resin film such as polyimide is formed on a substrate. It is possible.

[0262] That is, a light emitting device is formed on one substrate, and then a light emitting device is formed on another substrate. The light emitting device may be disposed on a different substrate. Examples include cellophane substrates, stone substrates, wood substrates, and cloth substrates (ceilings) in addition to the above-mentioned substrates. Natural fibers (silk, cotton, linen), synthetic fibers (nylon, polyurethane, polyester) or recycled Raw fibers (including acetate, cupra, rayon, recycled polyester, etc.), leather substrate By using these substrates, light-emitting devices that are not easily broken can be manufactured. , a light-emitting device having high heat resistance, a light-emitting device having a reduced weight, or a light-emitting device having a reduced thickness It can be a chair.

[0263] Also, for example, a field effect transistor (FET) is formed on the above-mentioned substrate, and the FET and A light emitting device 150 may be fabricated on the electrically connected electrodes. This allows for a FET By this, it is possible to manufacture an active matrix type display device that controls the driving of the light emitting device. .

[0264] The structure shown in this embodiment mode can be used in appropriate combination with other embodiment modes. Cut.

[0265] (Embodiment 2) In this embodiment, a mixture of organic compounds that can be suitably used in the light-emitting device 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. .

[0266] <Method for synthesizing organic compound represented by general formula (G1)> The organic compound represented by the above general formula (G1) can be synthesized by a synthesis method that applies various reactions. For example, the following synthesis schemes (S-1) and (S-2) can be used. It can be synthesized by mixing Compound 1, an arylamine (Compound 2), and an arylamine ( By coupling with compound 3), a diamine compound (compound 4) is obtained.

[0267] 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. It is possible to obtain organic compounds.

[0268] [ka]

[0269] [ka]

[0270] 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 heterocyclic aromatic ring, 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 length of 1 to 13; 1 ~X 8 Each independently has 3 to 10 carbon atoms. The alkyl groups listed below, substituted or unsubstituted cycloalkyl groups with 3 to 10 carbon atoms, The condensed ring or condensed heterocyclic ring is a trialkylsilyl group having a ring number of 3 or more and 12 or less. Aromatic rings include chrysene, phenanthrene, stilbene, acridone, and phenoxazine. , phenothiazine, etc. In particular, anthracene, pyrene, coumarin, quinacridone, etc. , perylene, tetracene, and naphthobisbenzofuran are preferred.

[0271] In the above synthesis schemes (S-1) and (S-2), When performing the Hubbard-Hartwig reaction, 10 ~X 13is a halogen group or a trifluoro 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 , tricyclohexylphosphine, di(1-adamantyl)-n-butylphosphine, 2-Dicyclohexylphosphino-2',6'-dimethoxy-1,1'-biphenyl, etc. Ligands can be used. In addition, organic bases such as sodium tert-butoxide and For example, 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 as follows: The reagents are not limited to these.

[0272] The reactions carried out in the above synthesis schemes (S-1) and (S-2) are carried out by the Buchwald reaction. The Hartwig reaction is not the only reaction that has been reported. coupling reaction using Grignard reagents, coupling reaction using copper or copper compounds The Ullmann reaction, which was previously used, can be used.

[0273] In the above synthesis scheme (S-1), when compound 2 and compound 3 have different structures, Compound 1 and compound 2 are reacted first to form a coupling product, and the resulting coupling product is It is preferable to react Compound 1 with Compound 3. In the case where compound 3 is reacted stepwise, compound 1 is preferably a dihalogen compound, and X 10and X 11 It is preferable to carry out the amination reaction selectively using different halogens one by one. I wish.

[0274] Furthermore, in the synthetic 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 reacted with compound 6 to obtain a coupling product. It is preferable to react the coupling product with compound 6.

[0275] <Method for synthesizing organic compound represented by general formula (G2)> The organic compound of one embodiment of the present invention represented by the general formula (G2) can be obtained by utilizing any organic reaction. As examples, two methods are shown below.

[0276] The first method consists of the following synthesis schemes (S-3) to (S-8). In this step, aniline compound (compound 7) and 1,4-cyclohexadiene-1,4-dicarboxylic acid This is a process for obtaining an amine compound (compound 9) by a condensation reaction of a phosphate compound (compound 8). The process is shown in Scheme (S-3). However, in one step, anilines having the same substituents are Two compounds (compound 7) can be condensed to introduce amino groups having the same substituents. In this case, it is preferable to carry out the reaction by adding 2 equivalents of an aniline compound (compound 7). In this case, a single target product can be obtained even if the carbonyl group of compound 8 does not have reaction selectivity. Cut.

[0277] Next, the amine compound (compound 9) is subjected to a condensation reaction with the aniline derivative (compound 10). The 1,4-cyclohexadiene compound (compound 11) can be obtained by the above. The process for obtaining the above is shown in Scheme (S-4).

[0278] Next, the 1,4-cyclohexadiene compound (compound 11) is oxidized in air. A terephthalic acid compound (compound 12) can be obtained by the above steps. is shown in Scheme (S-5).

[0279] Next, the terephthalic acid compound (compound 12) was subjected to ring condensation using an acid to give cinchona. A cridone compound (compound 13) can be obtained. The process for obtaining compound 13 is shown in Scheme ( S-6).

[0280] Next, the quinacridone compound (compound 13) and the aryl halide (compound 14) were mixed. By pulling, a quinacridone compound (compound 15) can be obtained. The process for obtaining compound 15 is shown in Scheme (S-7). Two aryl halides (compound 8) can be coupled together, each of which has the same substituent. To introduce an amino group, add 2 equivalents of an aryl halide (compound 14) to the same amount. In this case, it is preferable to carry out the reaction of the amino group of compound 14 without reaction selectivity. One objective is obtained.

[0281] Next, the quinacridone compound (compound 15) and the aryl halide (compound 16) were mixed. By this pulling, the organic compound represented by the above general formula (G2) can be obtained. The process is shown in Scheme (S-8).

[0282] [ka]

[0283] [ka]

[0284] The second method is shown in the following synthetic schemes (S-3) to (S-5), (S-9), and (S-1 The explanation of (S-3) to (S-5) is as above. The coupling of terephthalic acid compound (compound 12) and aryl halide (compound 14) By ringing, a diamine compound (compound 17) can be obtained. The process for obtaining the above-mentioned compound is shown in Scheme (S-9). Two aryl fluoride molecules can be coupled together, and the amino groups with the same substituents can be introduced. When aryl halide (compound 14) is added, the same reaction can be carried out by adding 2 equivalents of aryl halide. In this case, a single target product can be obtained even if the amino group of compound 12 does not have reaction selectivity. can be.

[0285] Next, the diamine compound (compound 17) and the aryl halide (compound 16) were coupled. Compound 18 can be obtained by silylating the compound 18. The process for obtaining this compound is shown in Scheme (S-10).

[0286] Finally, the diamine compound (compound 18) is subjected to ring condensation using an acid to obtain the compound represented by the above general formula ( The organic compound represented by the formula (G2) can be obtained. The process is shown in Scheme (S-11). However, during the ring condensation reaction, Ar 5 or Ar 6 The ortho hydrogen of the above reacts to form the above general formula ( G2) isomers of organic compounds may occur.

[0287] In scheme (S-11), a diamine compound having a symmetric structure (compound 18) is By using this, it is possible to synthesize an organic compound represented by the above general formula (G2).

[0288] [ka]

[0289] In the synthetic schemes (S-3) to (S-6) and (S-9) to (S-11), Al 1 represents an alkyl group such as a methyl group.

[0290] In the synthesis schemes (S-7) to (S-10), Y 1 and Y 2 are chlorine, bromine, iodine, Represents a triflate group.

[0291] In the synthetic schemes (S-7) to (S-10), the reaction can be carried out at high temperatures. It is preferable to carry out the Ullmann reaction since it is possible to obtain the target compound in a relatively high yield. The reagent that can be used in this reaction is copper or a copper compound, and the base is potassium carbonate. In the reaction, inorganic bases such as sodium hydride and the like can be used. The solvent was 2,2,6,6-tetramethyl-3,5-heptanedione, 1,3-dimethyl- 3,4,5,6-Tetrahydro-2(1H)pyrimidinone (DMPU), toluene, xylan In the Ullmann reaction, the reaction temperature is more favorable at 100°C or higher. The target product can be obtained in a short time and in high yield, so 2,2,6,6-tetramethyl- It is preferable to use 3,5-heptanedione, DMPU, and xylene. Also, the reaction temperature Since a higher temperature of 150°C or higher is more preferable, it is more preferable to use DMPU. The reagents that can be used in this reaction are not limited to those listed above. do not have.

[0292] In the synthesis schemes (S-7) to (S-10), Buchval synthesis using a palladium catalyst The Hartwig reaction can be carried out in which bis(dibenzylideneacetone) Palladium(0), palladium(II) acetate, [1,1-bis(diphenylphosphine (ferrocene)palladium(II) dichloride, tetrakis(triphenylphosphine ) Palladium(0), allylpalladium(II) chloride (dimer), etc. and tri(tert-butyl)phosphine, tri(n-hexyl)phosphine, tri Cyclohexylphosphine, di(1-adamantyl)-n-butylphosphine, 2-dicyclohexylphosphine Cyclohexylphosphino-2',6'-dimethoxybiphenyl, tri(ortho-tolyl) Phosphine, (S)-(6,6'-dimethoxybiphenyl-2,2'-diyl)bis(di isopropylphosphine (abbreviation: cBRIDP (registered trademark)) and other ligands are often used. In this reaction, organic bases such as sodium tert-butoxide and potassium carbonate are used. Inorganic bases such as ruthenium, cesium carbonate, sodium carbonate, etc. can be used in this reaction. As a solvent, toluene, xylene, benzene, tetrahydrofuran, dioxane, etc. are used. The reagents that can be used in the reaction are not limited to those listed above. isn't it.

[0293] The method for synthesizing the organic compound represented by the general formula (G2) of the present invention is a synthesis scheme. The present invention is not limited to the above (S-1) to (S-11).

[0294] R substituted on the quinacridone skeleton 1 ~R 10Specific examples of the aryl group include n-propyl and isopropyl groups. isopropyl group, n-butyl group, isobutyl group, tert-butyl group, cyclopropyl group, Cyclobutyl group, cyclopentyl group, cyclohexyl group, trimethylsilyl group, triethyl Examples of the silyl group include a silyl group and a tributylsilyl group.

[0295] X 9 and X 10 Substituted by Ar 5 And, X 11 and X 12 Substituted by Ar 6 As a concrete example is a 2-isopropylphenyl group, a 2-butylphenyl group, a 2-isobutylphenyl group, 2-tert-butylphenyl group, 2-isopropylphenyl group, 2-butylphenyl group , 3-propylphenyl group, 3-isobutylphenyl group, 3-tert-butylphenyl group group, 4-propylphenyl group, 4-isopropylphenyl group, 4-butylphenyl group, 4 -isobutylphenyl group, 4-tert-butylphenyl group, 3,5-dipropylphenyl group phenyl group, 3,5-diisopropylphenyl group, 3,5-dibutylphenyl group, 3,5-diphenyl -isobutylphenyl group, (3,5-di-tert-butyl)phenyl group, 1,3-diphenyl propylphenyl group, 1,3-diisopropylphenyl group, 1,3-dibutylphenyl group , 1,3-di-isobutylphenyl group, (1,3-di-tert-butyl)phenyl group, 1,3,5-triisopropylphenyl group, (1,3,5-tri-tert-butyl)phenyl group Examples of the aryl group include phenyl and 4-cyclohexylphenyl.

[0296] As described above, the organic compounds represented by the general formula (G1) and the general formula (G2) according to one embodiment of the present invention are However, the present invention is not limited to this, and other synthesis methods may be used. It may also be synthesized by

[0297] (Embodiment 3) In this embodiment, a light-emitting device having a different configuration from that of the light-emitting device shown in the first embodiment is used. The device will be described below with reference to FIG. 6. In FIG. 6, Parts having the same function as the symbols are shown with the same hatch pattern, and the symbols may be omitted. In addition, parts having similar functions are denoted by similar reference numerals, and detailed descriptions thereof will be omitted. There may be cases where this occurs.

[0298] <Light-emitting device configuration example 2> FIG. 6 is a schematic cross-sectional view of a light-emitting device 250. As shown in FIG.

[0299] The light-emitting device 250 shown in FIG. 6 has a pair of electrodes (electrodes 101 and 102) between which The light-emitting device has a plurality of light-emitting units (light-emitting unit 106 and light-emitting unit 108). Any one of the light emitting units is the same as the EL layer 100 shown in FIG. 1A. That is, the light emitting device 150 shown in FIG. Preferably, the light emitting device 250 has a plurality of light emitting units. In the light-emitting device 250, the electrode 101 functions as an anode and the electrode 102 functions as a cathode. However, the light emitting device 250 may be configured in the opposite manner. That's fine.

[0300] In addition, in the light-emitting device 250 shown in FIG. The light-emitting units 106 and 108 are laminated together, and a charge is generated between the light-emitting units 106 and 108. The light-emitting unit 106 and the light-emitting unit 108 have the same structure. For example, the light-emitting unit 108 may have the same structure as the EL layer 100. It is preferable to have one.

[0301] The light emitting device 250 also includes a light emitting layer 120 and a light emitting layer 170. The optical unit 106 includes a hole injection layer 111, a hole transport layer 112, an electron The light-emitting unit 108 also includes a light-emitting layer 113, and an electron-injecting layer 114. In addition to 70, a hole injection layer 116, a hole transport layer 117, an electron transport layer 118, and an electron injection layer Has 119.

[0302] Light-emitting device 250 may include any of the layers of light-emitting unit 106 and light-emitting unit 108. The compound according to one embodiment of the present invention may be contained in the layer. Of these, the light-emitting layer 120 or the light-emitting layer 170 is preferred.

[0303] The charge generating layer 115 is formed by adding an acceptor material, which is an electron acceptor, to a hole transporting material. Even if the structure is such that the electron transport material is a material having a donor property, the structure may be such that the donor property is added to the electron transport material. In addition, both of these configurations may be laminated.

[0304] When the charge generating layer 115 contains a composite material of an organic compound and an acceptor substance, As the composite material, the composite material which can be used for the hole-injection layer 111 shown in Embodiment 1 is used. The organic compounds include aromatic amine compounds, carbazole compounds, aromatic carbon compounds, etc. Various compounds such as hydrogen and polymer compounds (oligomers, dendrimers, polymers, etc.) are used. As an organic compound, 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 transport properties, enabling low-voltage and low-current operation. In addition, the anode side surface of the light-emitting unit is in contact with the charge generating layer 115. In this case, the charge generating 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 generating 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.

[0305] The charge generating layer 115 may be a layer including a composite material 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 material are combined. A layer including a composite material of a compound and an acceptor material, and a layer including a compound selected from an electron donor material. The compound may be combined with a compound having a high electron transporting property to form a layer. A layer including a composite material of an organic compound and an acceptor substance and a layer including a transparent conductive film are combined. It may be formed by combining the above.

[0306] The charge generating layer 115 sandwiched between the light emitting unit 106 and the light emitting unit 108 is 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 the electrode 1 injects holes into the other light-emitting unit. When a voltage is applied so that the potential of electrode 01 is higher than the potential of electrode 102, a charge is generated. Layer 115 injects electrons into light-emitting unit 106 and holes into light-emitting unit 108. .

[0307] From the viewpoint of light extraction efficiency, the charge generating layer 115 is required to be transparent to visible light (specifically, It is preferable that the charge generating layer 115 has a visible light transmittance of 40% or more. In addition, the charge generating layer 115 has a lower electrical conductivity than the pair of electrodes (the electrodes 101 and 102). But it still works.

[0308] When the charge generating layer 115 is formed using the above-mentioned material, the light emitting layer is laminated. In this case, the increase in the driving voltage can be suppressed.

[0309] In addition, although the light emitting device having two light emitting units has been described with reference to FIG. The same can be applied to a light-emitting device having three or more stacked light-emitting units. As shown in the light-emitting device 250, a plurality of light-emitting units are electrically connected between a pair of electrodes. By separating the layers, it is possible to emit high-intensity light while keeping the current density low. It is also possible to realize a light-emitting device with a longer life and a light-emitting device with lower power consumption. It is possible.

[0310] In each of the above configurations, the light emitting units 106 and 108 are 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 same color light emission properties. When the material is included, the light emitting device 250 is a light emitting device that exhibits high light emission brightness at a small current value. In addition, the light-emitting unit 106 and the light-emitting unit 108 are different from each other. In the case where the light-emitting device 250 has guest materials capable of emitting light of different colors, the light-emitting device 250 can emit multiple colors. In this case, the light-emitting layer 120 and the light-emitting layer 170 are preferably a light-emitting device that emits light. By using multiple luminescent materials with different luminescent wavelengths for either or both of them, luminescence The emission spectrum exhibited by device 250 is a composite of emissions having different emission peaks. Therefore, the emission spectrum has at least two maxima.

[0311] The above-mentioned structure is also suitable for obtaining white light emission. By making the lights complementary to each other, white light can be obtained. The design is such that the resulting white light has a high light emission, or at least light emission having red, green and blue colors. It is preferable to select a material that is

[0312] The light-emitting layer 130 shown in the first embodiment may be used for one or both of the light-emitting layer 120 and the light-emitting layer 170. By using this configuration, it is possible to obtain light emitting devices with good light emitting efficiency and reliability. A device can be obtained. The guest material contained in the light-emitting layer 130 is a fluorescent material. Therefore, the light-emitting layer 120 and / or the light-emitting layer 170 may be formed using the light-emitting layer shown in the first embodiment. By using the configuration of layer 130, a light emitting device having high efficiency and high reliability can be obtained. Cut.

[0313] In addition, in the case of a light-emitting device in which three or more light-emitting units are stacked, each light-emitting unit The emission colors of the guest materials used in may be the same or different. In the case where a plurality of light-emitting units each having the same light emission are provided, the plurality of light-emitting units may be connected to each other through a small current This configuration is suitable for adjusting the color of emitted light. In particular, it is possible to use guest materials having different luminous efficiencies and different luminescent colors. For example, when the light-emitting unit has three layers, the light-emitting unit has fluorescent materials of the same color. The light-emitting device has two layers of light-emitting units each having a phosphorescent material that emits light of a different color from the fluorescent material. By using a single layer of optical units, the emission intensity of fluorescent and phosphorescent light can be adjusted. In other words, the intensity of the emitted color can be adjusted by changing the number of light-emitting units.

[0314] 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, 2 layers of light-emitting units containing blue fluorescent material and 1 layer of light-emitting unit containing yellow phosphorescent material A light-emitting device including a layer, a light-emitting unit including a blue fluorescent material, and a layer including a red phosphorescent material. and a light-emitting device having one layer of a light-emitting unit containing a green phosphorescent material or a blue fluorescent material. 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 of optical units is preferable because it can efficiently emit white light. In this manner, the light-emitting device of one embodiment of the present invention can be appropriately combined with a phosphorescent light-emitting layer. can.

[0315] In addition, in a light-emitting device having two layers of the above-mentioned fluorescent light-emitting unit and one layer of the phosphorescent light-emitting unit, The phosphorescent light-emitting unit is an emitting layer having the configuration of the light-emitting layer 130 described in the first embodiment. The configuration of the light-emitting layer 130 described in the first embodiment can be replaced with a unit. By using such a material, it is possible to realize a fluorescent-emitting layer having the same luminous efficiency as a phosphorescent-emitting layer. .

[0316] In addition, at least one of the light-emitting layer 120 and the light-emitting layer 170 is further divided into layers, Each of the divided layers 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 a hole transporting property is used as the host material of the first light-emitting layer, and a material having a hole transporting property 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 in the light-emitting layer and the second light-emitting layer may be the same or different. Even if a material has a function of emitting light of the same color, it is preferable that the material has a function of emitting light of different colors. The material may be a material having the following function: By using a material with a structure that has three primary colors or four or more colors, it is possible to obtain white light with high color rendering. It is also possible.

[0317] As the guest material of the light-emitting layer of the phosphorescent light-emitting unit described in the third embodiment, for example, The phosphorescent materials shown in the following can be used.

[0318] Examples of phosphorescent materials having a blue or green emission peak include tris{2-[5 -(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-trimethylphenyl riazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: Ir( mpptz-dmp)3), tris(5-methyl-3,4-diphenyl-4H-1,2, 4-Triazolate)iridium(III) (abbreviation: Ir(Mptz)3), tris[4- (3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazola Tris[3-(5 -biphenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazolato] Iridium(III) (abbreviation: Ir(iPr5btz)3), such as 4H-triazolidine Organometallic iridium complexes with a tris[3-methyl-1-(2-methylphenyl) nyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation : Ir(Mptz1-mp)3), tris(1-methyl-5-phenyl-3-propyl- 1H-1,2,4-Triazolate)iridium(III) (abbreviation: Ir(Prptz1- Organometallic iridium complexes with 1H-triazole skeletons such as fac -Tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazo[3,4-diisopropylphenyl] ... Iridium(III) (abbreviation: Ir(iPrpmi)3), tris[3-(2,6- Dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium Ir(dmpimpt-Me)3) Organometallic iridium complexes and bis[2-(4',6'-difluorophenyl)pyridinium] Nat-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 (III ) picolinate (abbreviation: Ir(CF3ppy)2(pic)), bis[2-(4',6' -Difluorophenyl)pyridinato-N,C 2’ ]Iridium(III) acetylacetonate Phenylpyridine derivatives bearing electron-withdrawing groups such as acac-to (abbreviation: FIr(acac)) Among the above, the 4H-triazolidinediamine is an organometallic iridium complex. Nitrogen-containing five-membered heterocycles such as azole skeletons, 1H-triazole skeletons and imidazole skeletons The organometallic iridium complexes with the iridium skeleton have high triplet excitation energy and are highly reliable and luminescent. It is particularly preferable because it has excellent light efficiency. -Octaethyl-21H,23H-porphyrin platinum(II) (abbreviation: PtOEP) Platinum complexes such as tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato ](Monophenanthroline)europium(III) (abbreviation: Eu(TTA)3(Phe Rare earth metal complexes such as n) can also be used.

[0319] In addition, examples of substances having a green or yellow emission peak include tris(4-methylphenyl) Ir(mppm)3, Tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: I r(tBuppm)3), (acetylacetonato)bis(6-methyl-4-phenylpyridine Iridium(III) (abbreviation: Ir(mppm)2(acac)), (acetylacetonate ruacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium( III) (abbreviation: Ir(tBuppm)2(acac)), (acetylacetonato)bis [4-(2-norbornyl)-6-phenylpyrimidinato]iridium(III) (abbreviation Ir(nbppm)2(acac)), (acetylacetonato)bis[5-methyl-6 -(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: Ir(mpmppm)2(acac)), (acetylacetonato)bis{4,6-dimethyl 2-[6-(2,6-dimethylphenyl)-4-pyrimidinyl-κN3]phenyl- {κC}iridium(III) (abbreviation: Ir(dmppm-dmp)2(acac)), ( Acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III)( Abbreviation: Ir(dppm)2(acac) (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazine) Iridium(III) (abbreviation: Ir(mppr-Me)2(acac)), (acetylacetonate arylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinate)irid Pyrazine skeleton such as Ir(III) (abbreviation: Ir(mppr-iPr)2(acac)) Organometallic iridium complexes and tris(2-phenylpyridinato-N,C 2’ ) Iridium(III) (abbreviation: Ir(ppy)3), bis(2-phenylpyridinato-N ,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(ppy)2(ac ac)), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: Ir(bzq)2(acac)), tris(benzo[h]quinolinato)iridium Ir(III) (abbreviation: Ir(bzq)3), tris(2-phenylquinolinato-N,C 2 ’ ) Iridium(III) (abbreviation: Ir(pq)3), bis(2-phenylquinolinato- N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(pq)2(ac Organometallic iridium complexes with pyridine skeletons such as bis(2,4-difluorophenyl) and Venyl-1,3-oxazolato-N,C 2’ ) Iridium(III) acetylacetoner Ir(dpo)2(acac)), bis{2-[4'-(perfluorophenyl (phenyl)pyridinato-N,C 2’}Iridium(III) acetylacetonate ( Abbreviation: Ir(p-PF-ph)2(acac)), bis(2-phenylbenzothiazol -N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(bt)2(a In addition to organometallic iridium complexes such as tris(acetylacetonato)(monophenyl) Anthroline) terbium(III) (abbreviation: Tb(acac)3(Phen)) Among the above, the organometallic iridium complexes having a pyrimidine skeleton are Dium complexes are particularly preferred because they are remarkably excellent in reliability and luminous efficiency.

[0320] Examples of substances having a yellow or red emission peak include diisobutyryl Methanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(II I) (abbreviation: Ir(5mdppm)2(dibm)), bis[4,6-bis(3-methyl Phenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: Ir (5mdppm)2(dpm)), bis[4,6-di(naphthalene-1-yl)pyrimidinyl] Nato](dipivaloylmethanato)iridium(III) (abbreviation: Ir(d1npm)2( Organometallic iridium complexes with pyrimidine skeletons such as (acetylacetamide) Iridium(III) r(tppr)2(acac)), bis(2,3,5-triphenylpyrazine)(dipyridine) Valoylmethanato)iridium(III) (abbreviation: Ir(tppr)2(dpm)), ( Acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]i Ir(Fdpq)2(acac) and other pyrazine-based compounds Organometallic iridium complexes and tris(1-phenylisoquinolinato-N,C 2’ ) Iridium(III) (abbreviation: Ir(piq)3), bis(1-phenylisoquinolinato -N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(piq)2( In addition to organometallic iridium complexes with pyridine skeletons such as acac), 2,3,7, 8,12,13,17,18-Octaethyl-21H,23H-porphyrin platinum(II) ) (abbreviation: PtOEP) and tris(1,3-diphenyl-1,3-propanediol). (Eu(DB))(monophenanthroline)europium(III) M) 3(Phen)), tris[1-(2-thenoyl)-3,3,3-trifluoroacetate [Tonato](monophenanthroline)europium(III) (abbreviation: Eu(TTA)3( Among the above, rare earth metal complexes such as pyrimidine skeletons are Organometallic iridium complexes having the above structure are particularly preferred because they are extremely reliable and have excellent luminous efficiency. In addition, organometallic iridium complexes with pyrazine skeletons can emit red light with good chromaticity. can be done.

[0321] The host material of the phosphorescent light-emitting unit may be the hole transport material and / or the electron transport material. A quantum transport material can be used.

[0322] In addition, the above-mentioned fluorescent light-emitting unit may have a structure other than that of the light-emitting layer 130 shown in the first embodiment. The guest material used in the fluorescent light-emitting unit is not particularly limited. However, fluorescent compounds include anthracene derivatives, tetracene derivatives, and chrysene derivatives. , phenanthrene derivatives, pyrene derivatives, perylene derivatives, stilbene derivatives, acrylamide Preferred are amine derivatives, coumarin derivatives, phenoxazine derivatives, and phenothiazine derivatives. For example, the following substances can be used:

[0323] Specifically, 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2 ,2'-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl -9-anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2 BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoro 1,6-Pyrene-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn) , N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H -fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMem FLPAPrn), N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl )phenyl]-N,N'-bis(4-tert-butylphenyl)-pyrene-1,6-di Amine (abbreviation: 1,6tBu-FLPAPrn), N,N'-bis[4-(9-phenyl -9H-fluoren-9-yl)phenyl]-N,N'-diphenyl-3,8-dicyclo Hexylpyrene-1,6-diamine (abbreviation: ch-1,6FLPAPrn), N,N'- Bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenylstyrene Ben-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl )-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA ), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-an tolyl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4 -(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine ( Abbreviation: PCAPA), Perylene, 2,5,8,11-tetra(tert-butyl)perylene TBP, 4-(10-phenyl-9-anthryl)-4'-(9-phenyl -9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), N,N ''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene ) Bis[N,N',N'-triphenyl-1,4-phenylenediamine] (abbreviation: DPA BPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthryl phenyl]-9H-carbazol-3-amine (abbreviation: 2PCAPPA), N-[4-( 9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl- 1,4-Phenylenediamine (abbreviation: 2DPAPPA), N,N,N',N',N'', N'',N''',N'''-Octaphenyldibenzo[g,p]chrysene-2,7,1 0,15-Tetraamine (abbreviation: DBC1), Coumarin 30, N-(9,10-diphenyl (2-anthryl)-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-an Tolyl]-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCABP hA), N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl N-[9,10-bis(1, 1'-biphenyl-2-yl)-2-anthryl]-N,N',N'-triphenyl-1 ,4-Phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis(1,1'-biphenyl) Phenyl-2-yl)-N-[4-(9H-carbazol-9-yl)phenyl]-N- Phenylanthracene-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenyl Nyl anthracene-9-amine (abbreviation: DPhAPhA), Coumarin 6, Coumarin 545 T, N,N'-diphenylquinacridone (abbreviation: DPQd), rubrene, 2,8-di-t ert-Butyl-5,11-bis(4-tert-butylphenyl)-6,12-diphenyl Nyltetracene (abbreviation: TBRb), Nile Red, 5,12-bis(1,1'-biphenyl) 2-(2-(2-yl)-6,11-diphenyltetracene (abbreviation: BPT), -[4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyran-4-yl 2-(2-methyl-6-[(2-(2, 3,6,7-Tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl N,N,-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM2) N',N'-tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation :p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-methylphenyl) acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl Chil-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizine-9-yl DCJTI ), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3 ,6,7-Tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl ]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2 ,6-Bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4- 2-{2,6-bis[2-(8-phenylenediphenyl)propanedinitrile (abbreviation: BisDCM), -Methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5 H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene Propanedinitrile (abbreviation: BisDCJTM), 5,10,15,20-tetraphenyl Rubisbenzo[5,6]indeno[1,2,3-cd:1',2',3'-lm]perylene DBP, etc.

[0324] The host material of the fluorescent light-emitting unit may be the hole transport material and / or the electron transport material. Note that this embodiment mode may be appropriately combined with other embodiment modes. It is possible to match.

[0325] (Embodiment 4) In this embodiment, a light emitting device using the light emitting device described in the first and third embodiments is The container will be described with reference to Figs. 7A and 7B.

[0326] FIG. 7A is a top view showing a light-emitting device, and FIG. 7B is a cross-sectional view taken along lines AB and CD in FIG. 7A. FIG. 1 is a diagram showing a light emitting device shown in dotted lines as controlling the light emission of the light emitting device. A driving circuit section (a source side driving circuit) 601, a pixel section 602, a driving circuit section (a gate side driving circuit In addition, 604 is a sealing substrate, 625 is a drying material, and 605 is a sealing material. The inside surrounded by the sealing material 605 forms a space 607 .

[0327] 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 the signals to be input, and the FPC (flexible printed circuit board) is the external input terminal. Video signal, clock signal, start signal, reset signal, etc. from the 609 Although only the FPC is shown here, the 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 the FPC or P This includes the state where the WB is installed.

[0328] Next, the cross-sectional structure of the light-emitting device will be described with reference to FIG. 6 shows a source side driver circuit 601 and one pixel in a pixel portion 602.

[0329] The source side driver circuit 601 includes an n-channel TFT 623 and a p-channel TFT 624. The driver circuit is a combination of various CMOS circuits, It may be formed of a MOS circuit or an NMOS circuit. In this embodiment, the driving circuit is formed on the substrate. Although the figure shows an integrated driver, this is not necessarily required. The driver circuit may be mounted on a substrate. It can also be formed externally.

[0330] 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 input. An insulator 614 is formed so as to cover the end of the electrode 613. The insulating layer can be formed by using a photosensitive resin film having a mold.

[0331] In order to improve the coverage of the film formed on the insulator 614, the insulator 614 is The upper end or the lower end is formed to have a curved surface. For example, 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.

[0332] 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 material with a large capacitance. For example, an ITO film or an indium tin oxide film containing silicon. 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 nitride film can be used. The resistance of the anode is low, good ohmic contact can be achieved, and the anode can function as well. This can be done.

[0333] The EL layer 616 is formed by deposition using a deposition mask, inkjet printing, or spin coating. The EL layer 616 can be formed by various methods such as the above. The polymer may be a polymer compound (including an oligomer or a dendrimer).

[0334] Furthermore, a material for a 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 alloys or compounds of these) 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 made thin. A thin metal film and a transparent conductive film (ITO, an oxide film containing 2 wt% to 20 wt% zinc oxide) Indium tin oxide, silicon-containing indium tin oxide, zinc oxide (ZnO, etc.) It is better to use.

[0335] The first electrode 613, the EL layer 616, and the second electrode 617 constitute a light-emitting device 618. The light emitting device 618 has the configurations of the first and second embodiments. It is preferable that the pixel portion is a light-emitting device. However, in the light emitting device of this embodiment, The present invention includes both light emitting devices having the above-mentioned configuration and light emitting devices having other configurations. That's fine.

[0336] Furthermore, the sealing substrate 604 is bonded to the substrate 610 of the light emitting device with a sealing material 605. As a result, the light is emitted into a space 607 surrounded by the substrate 610, the sealing substrate 604, and the sealant 605. The structure is provided with an optical device 618. The space 607 is filled with a filler. In addition to being filled with inert gas (nitrogen, argon, etc.), it is also possible to fill it with resin or dry It may also be filled with a mixture of phosphate phosphate, phosphate ...

[0337] It is preferable to use epoxy resin or glass frit for the sealing material 605. It is desirable that these materials are 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, for example, polyester or acrylic can be used.

[0338] As described above, the light emitting devices described in the first and third embodiments are used to emit light. You can get the equipment.

[0339] <Light-emitting device configuration example 1> FIG. 8 shows an example of a display device in which a light-emitting device that emits white light is formed, and a color layer (color An example of a light-emitting device having a reflective filter is shown below.

[0340] FIG. 8A shows a substrate 1001, an insulating base film 1002, a gate insulating film 1003, and a gate electrode 1004. 06, 1007, 1008, a first interlayer insulating film 1020, a second interlayer insulating film 1021, A side portion 1042, a pixel portion 1040, a driving circuit portion 1041, and a first electrode 102 of a light-emitting device 4W, 1024R, 1024G, 1024B, EL layer 1028, the second electrode of the light-emitting device Pole 1029, sealing substrate 1031, sealing material 1032, red pixel 1044R, green pixel 10 44G, blue pixel 1044B, and white pixel 1044W are shown.

[0341] 8A and 8B show colored layers (red colored layer 1034R, green colored layer 1034G, A blue colored layer (1034B) is provided on the transparent substrate 1033. A transparent substrate having a colored layer and a black layer may be provided. The material 1033 is aligned and fixed to the substrate 1001. The colored layer and the black layer are It is covered with an overcoat layer 1036. Also, in FIG. 8A, light passes through the colored layer. There are two types of light-emitting layers: one that emits light directly to the outside without passing through the other, and one that transmits light through the colored layers of each color to the outside. The light that does not pass through the colored layer becomes white, and the light that passes through the colored layer becomes red, blue, and green, so a four-color image is produced. It is possible to express images using only natural elements.

[0342] In FIG. 8B, a red colored layer 1034R, a green colored layer 1034G, and a blue colored layer 1034B is formed between the gate insulating film 1003 and the first interlayer insulating film 1020. As shown in FIG. 1B, the colored layer may be provided between the substrate 1001 and the sealing substrate 1031 .

[0343] In the light emitting device described above, the 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 emitted from the sealing substrate 1031 side. The light emitting device may have a structure for extracting light (top emission type).

[0344] <Light-emitting device configuration example 2> A cross-sectional view of a top-emitting light-emitting device is shown in FIG. 9A and FIG. 9B. In this case, the substrate 1 001 can be a light-opaque substrate. Connect the TFT and the anode of the light-emitting device. 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. This insulating film is planarized. The third interlayer insulating film 1037 may have the same function as the second interlayer insulating film 1021. In addition to the above materials, various other materials can be used.

[0345] The lower electrode 1025W, the lower electrode 1025R, the lower electrode 1025G, and the lower electrode Although the electrode 1025B 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 is 1025W, It is preferable that the lower electrode 1025R, the lower electrode 1025G, and the lower electrode 1025B are 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 1 A microcavity structure is applied between the lower electrode 1025B and the lower electrode 1025G to detect light of a specific wavelength. The EL layer 1028 has a structure similar to that of the first embodiment and the second embodiment. The device has a configuration as described in embodiment 3, and has a device structure capable of obtaining white light emission.

[0346] In Figs. 8A, 8B, 9A, and 9B, the EL layer configuration from which white light can be obtained is This can be realized by using multiple light-emitting layers or multiple light-emitting units. However, the configuration for obtaining white light emission is not limited to the above.

[0347] In the top emission structure as shown in FIG. 9A and FIG. 9B, the colored layer (red colored layer 1034R) , green colored layer 1034G, and blue colored layer 1034B) are provided on the sealing substrate 1031. The sealing substrate 1031 has a black layer ( A colored layer (red colored layer 1034R, green colored layer 1034R, black matrix) 1030 may be provided. The colored layer 1034G, the blue colored layer 1034B) and the black layer (black matrix) The sealing substrate 1031 may be covered with an overcoat layer. A substrate is used.

[0348] In addition, while FIG. 9A shows a configuration for full-color display using three colors, red, green, and blue, FIG. As shown in the figure, full color display may be performed using four colors: red, green, blue, and white. The configuration for displaying the image is not limited to these. For example, a full display using four colors, red, green, blue, and yellow, may be used. A color display may also be performed.

[0349] A light-emitting device according to an embodiment of the present invention uses a fluorescent material as a guest material. Compared with phosphorescent materials, the spectrum of the phosphorescent material is sharper, so it is possible to obtain light emission with high color purity. Therefore, by using the light-emitting device in the light-emitting device shown in this embodiment, As a result, a light-emitting device with high color reproducibility can be obtained.

[0350] (Embodiment 5) In this embodiment, an electronic device and a display device according to one embodiment of the present invention will be described.

[0351] According to one embodiment of the present invention, a highly reliable electronic device and display having a flat surface and high light emission efficiency can be provided. According to one embodiment of the present invention, a reliable display device having a curved surface and high luminous efficiency can be manufactured. In addition, the present invention can provide highly reliable electronic devices and display devices. The device can be obtained.

[0352] Examples of electronic devices include television sets, desktop or notebook personal computers, etc. Computers, computer monitors, digital cameras, digital video cameras digital photo frames, mobile phones, portable game consoles, personal digital assistants, audio playback equipment Examples include large gaming machines such as pachinko machines.

[0353] A mobile information terminal 900 shown in FIG. 10A and FIG. 10B includes a housing 901, a housing 902, a display unit 90 3, and a hinge portion 905.

[0354] The housing 901 and the housing 902 are connected by a hinge portion 905. The mobile information terminal 900 includes: From the folded state (FIG. 10A), it can be unfolded as shown in FIG. 10B. This makes it easy to carry around, and the large display area makes it easy to see when in use. Excellent in.

[0355] The portable information terminal 900 has a housing 901 and a housing 902 connected by a hinge portion 905. A flexible display unit 903 is provided.

[0356] A light-emitting device manufactured according to one embodiment of the present invention can be used for the display portion 903. This makes it possible to manufacture a highly reliable portable information terminal.

[0357] The display unit 903 is capable of displaying at least one of document information, still images, and moving images. When document information is displayed on the display unit, the portable information terminal 900 is used as an electronic book terminal. It can be used as such.

[0358] When the portable information terminal 900 is unfolded, the display portion 903 is held in a state in which 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 supported by the housing 901 and the other parts of the display unit 903. Pixels are arranged continuously across the body 902, enabling curved surface display.

[0359] The display unit 903 functions as a touch panel and can be operated by a finger, a stylus, etc. can.

[0360] It is preferable that the display unit 903 is composed of one flexible display. This makes it possible to perform continuous display without interruption between the housing 901 and the housing 902. In addition, a display may be provided in each of the housings 901 and 902. You may do so.

[0361] The hinge portion 905 is a portion 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 greater than 90 degrees and less than 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.

[0362] If the hinge portion 905 has a locking mechanism, the display portion 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.

[0363] 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 an indentation or the like.

[0364] 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 the like.

[0365] A portable information terminal 910 shown in FIG. 10C includes a housing 911, a display unit 912, an operation button 913, It has an external connection port 914, a speaker 915, a microphone 916, a camera 917, etc.

[0366] A light-emitting device manufactured according to one embodiment of the present invention can be used for the display portion 912. This makes it possible to manufacture portable information terminals with a high yield.

[0367] The mobile information terminal 910 has a touch sensor on the display unit 912. All operations, such as inputting characters, can be performed by touching the display 912 with a finger or a stylus. It can be done.

[0368] In addition, the operation button 913 is operated to turn the power on and off, and to display on the display unit 912. For example, you can change the type of image displayed on the main screen from the email composition screen. You can switch to the menu screen.

[0369] In addition, a detection device such as a gyro sensor or an acceleration sensor is provided inside the portable information terminal 910. By providing the above, the orientation of the mobile information terminal 910 (vertical or horizontal) can be determined and the screen of the display unit 912 can be adjusted. The display orientation can be switched automatically. The screen orientation can also be switched by The input is made by touching the display unit 912, by operating the operation button 913, or by inputting voice using the microphone 916. It can also be performed by using force or the like.

[0370] The mobile information terminal 910 is, for example, one or more devices selected from a telephone, a notebook, an information viewing device, etc. Or it has multiple functions. Specifically, it can be used as a smartphone. The information terminal 910 is, for example, a mobile phone, an e-mail, a document viewing and creation, a music playback, a video It can run various applications such as playback, internet communication, and games. do.

[0371] The camera 920 shown in FIG. 10D includes a housing 921, a display unit 922, an operation button 923, and a shutter. The camera 920 has a detachable lens 926 attached thereto. It is being done.

[0372] A light-emitting device manufactured according to one embodiment of the present invention can be used for the display portion 922. This makes it possible to manufacture a highly reliable camera.

[0373] 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 together.

[0374] The camera 920 captures still or moving images by pressing the shutter button 924. In addition, the display unit 922 has a function as a touch panel. It is also possible to capture an image by touching the

[0375] The camera 920 can be equipped with a strobe device, viewfinder, etc. Alternatively, these may be incorporated into the housing 921.

[0376] FIG. 11A is a schematic diagram showing an example of a cleaning robot.

[0377] The cleaning robot 5100 has a display 5101 arranged 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.

[0378] The cleaning robot 5100 moves by itself, detects dirt 5120, and sucks it out from the suction port on its bottom. It can suck up dirt.

[0379] In addition, the cleaning robot 5100 analyzes the image captured by the camera 5102 and detects walls, furniture, or It can detect obstacles such as steps. It can also detect wiring and other obstacles by image analysis. If an object that is likely to get tangled in the brush 5103 is detected, the rotation of the brush 5103 can be stopped. can.

[0380] The display 5101 can display the remaining battery level, the amount of dirt sucked up, etc. The route traveled by the cleaning robot 5100 can be displayed on the display 5101. In addition, the display 5101 may be a touch panel, and the operation buttons 5104 may be a display. It may be provided in the ray 5101.

[0381] 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 state of the room even when he / she 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 at 5140.

[0382] The light-emitting device according to one embodiment of the present invention can be used in the display 5101 .

[0383] The robot 2100 shown in FIG. 11B includes a computing device 2110, an illuminance sensor 2101, a microcomputer, and a Phone 2102, upper camera 2103, speaker 2104, display 2105, lower It is equipped with a camera 2106, an obstacle sensor 2107, and a movement mechanism 2108.

[0384] 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 user can communicate with the computer using the computer 2102 and the speaker 2104. It is possible.

[0385] The display 2105 has a function of displaying various information. It is possible for the user to display desired information on the display 2105. The display 2105 may be equipped with a touch panel. The information terminal may be a terminal that can be used for charging and discharging the battery. and enables data transfer.

[0386] 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 of the robot 210 using the moving mechanism 2108. When the robot 21 moves forward, it can sense the presence or absence of obstacles in its path. 00 uses an upper camera 2103, a lower camera 2106, and an obstacle sensor 2107. It is possible for the robot to recognize its surrounding environment and move around safely.

[0387] The light-emitting device according to one embodiment of the present invention can be used in the display 2105 .

[0388] FIG. 11C is a diagram showing an example of a goggle-type display. The goggle-type display is For example, a housing 5000, a display unit 5001, a speaker 5003, an LED lamp 5004, an operation Operation key (including power switch or operation switch), connection terminal 5006, sensor 5007 (force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemicals quality, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, or one that includes a function for measuring infrared rays), microphone 5008, second display unit 5002, a support portion 5012, earphones 5013, etc.

[0389] The light-emitting device according to one embodiment of the present invention can be used for the display portion 5001 and the second display portion 5002. can.

[0390] 12A and 12B show a foldable mobile information terminal 5150. The portable information terminal 5150 includes a housing 5151, a display area 5152, and a bending portion 5153. FIG. 12A shows a portable information terminal 5150 in an unfolded state. The mobile information terminal 5150 is shown in a folded state. The mobile information terminal 5150 has a large display area Despite having 5152, it folds up compactly and is highly portable.

[0391] 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 expandable 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.

[0392] The display area 5152 is a touch panel (input / output) equipped with a touch sensor (input device). The light-emitting device according to one embodiment of the present invention may be used in the display region 5152. can be done.

[0393] This embodiment mode can be combined with other embodiment modes as appropriate.

[0394] (Embodiment 6) In this embodiment, an example in which the light-emitting device of one embodiment of the present invention is applied to various lighting devices will be described. The above will be described with reference to FIG. 13. By using the light-emitting device according to one embodiment of the present invention, A highly reliable lighting device with good luminous efficiency can be manufactured.

[0395] The light-emitting device of one embodiment of the present invention can be manufactured over a flexible substrate, thereby enabling a light-emitting device having a curved surface to be formed. It is possible to realize electronic devices and lighting devices having a light-emitting region.

[0396] In addition, a light-emitting device to which the light-emitting device of one embodiment of the present invention is applied can be used for automobile lighting. For example, lighting can be installed on the windshield, ceiling, etc.

[0397] FIG. 13 shows an example in which the light-emitting device is used as an indoor lighting device 8501. Since the device can be enlarged, a large-area lighting device can be formed. In addition, by using a curved housing, a lighting device 8502 with a curved light-emitting area is formed. The light-emitting device shown in this embodiment has a thin film shape, and the design of the housing can be changed. This allows for a high degree of freedom, making it possible to create lighting devices with a wide variety of elaborate designs. Furthermore, a large lighting device 8503 may be provided on the wall of the room. A touch sensor may be provided in 8502 and 8503 to turn the power on or off.

[0398] In addition, by using a light-emitting device on the surface of the table, it can function as a table. In addition, the lighting device 8504 may be a lighting device that includes a light emitting device. By using this, it is possible to create a lighting device that also functions as furniture.

[0399] As described above, a lighting device and an electronic device can be manufactured by using a light-emitting device according to one embodiment of the present invention. Note that the lighting device and electronic device to which the present invention can be applied are the same as those described in this embodiment. The present invention can be applied to electronic devices in a wide range of fields, not limited to the above.

[0400] The structure described in this embodiment may be used in appropriate combination with structures described in other embodiments. There can be. EXAMPLES

[0401] Example 1 In this example, a manufacturing example of a light-emitting device according to one embodiment of the present invention and a comparative light-emitting device are shown. The characteristics of the device will be described. The structure of the light-emitting device fabricated in this example is the same as that shown in FIG. The details of the device structure are shown in Tables 1 to 6. Note that the elements represented by x1 in Tables 1 to 4 are The values ​​represented by x2 are those shown in Table 5, and the values ​​represented by x3 are those shown in Table 6. The structures and abbreviations of the compounds used are shown below.

[0402] [ka]

[0403] [ka]

[0404] [ka]

[0405] [Table 1]

[0406] [Table 2]

[0407] [Table 3]

[0408] [Table 4]

[0409] [Table 5]

[0410] [Table 6]

[0411] <Fabrication of light-emitting devices> A method for fabricating the light-emitting device according to this embodiment will be described below.

[0412] <Fabrication of Light-Emitting Devices 2 to 5> 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).

[0413] 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 deposition was carried out to a thickness of 40 nm.

[0414] Next, a hole transport layer 112 was formed on the hole injection layer 111 by depositing PCCP to a thickness of 20 nm. The deposition was carried out so that

[0415] Next, mPCCzPTzn-02 and PC CP and Ir(mpptz-diBuCNp)3 and 2tBu-ptBuDPhA2Ant h and the weight ratio (mPCCzPTzn-02:PCCP:Ir(mpptz-diBuC Np)3:2tBu-ptBuDPhA2Anth) to 0.5:0.5:0.1:x1 The layers were then co-evaporated to a thickness of 30 nm. -02, PCCP, Ir(mpptz-diBuCNp)3, and 2tBu-ptBuD PhA2Anth and the weight ratio (mPCCzPTzn-02:PCCP:Ir(mppt z-diBuCNp)3:2tBu-ptBuDPhA2Anth)0.8:0.2: The layers were co-evaporated to a thickness of 10 nm so that the ratio of the layers was 0.1:x1. In the present study, Ir(mpptz-diBuCNp)3 is a phosphorescent material with a five-membered ring. In addition, 2tBu-ptBuDPhA2Anth is a fluorescent material having a protecting group. In addition, the value of x1 differs for each light-emitting device. are the values ​​shown in Table 5.

[0416] Next, mPCCzPTzn-02 was deposited to a thickness of 100 nm on the light-emitting layer 130 as the electron transport layer 118. They were then evaporated in sequence to a thickness of 20 nm, and NBPhen to a thickness of 10 nm. Next, LiF was deposited on the electron transport layer 118 to form the electron injection layer 119 to a thickness of 1 nm. The vapor was evaporated.

[0417] 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.

[0418] Next, in a glove box with a nitrogen atmosphere, a glass substrate for sealing is By using an EL sealant to fix the organic material to a glass substrate, a light-emitting device is formed. Specifically, the organic material was formed on the glass substrate, and the light-emitting device 5 was sealed. A sealant is applied to the glass substrate, and the glass substrate is bonded to another glass substrate for sealing. 365 nm ultraviolet light at 6 J / cm 2 The film was irradiated with light and then heat-treated at 80°C for 1 hour. Thus, light-emitting devices 2 to 5 were obtained.

[0419] <Light emitting device 7 to light emitting device 10, light emitting device 12 to light emitting device 15, light emitting Light emitting device 17 to light emitting device 19, light emitting device 21 to light emitting device 24, light emitting device Light emitting device 26 to light emitting device 28, light emitting device 30 to light emitting device 33, and comparative light emitting device Devices 1, 6, 11, 16, 20, 25, 29 and comparative light-emitting devices 34 to Construction of Chair 38≫ Light emitting devices 7 to 10, light emitting devices 12 to 15, light emitting Light emitting device 17 to light emitting device 19, light emitting device 21 to light emitting device 24, light emitting device Light emitting device 26 to light emitting device 28, light emitting device 30 to light emitting device 33, and comparative light emitting device Devices 1, 6, 11, 16, 20, 25, 29 and comparative light-emitting devices 34 to The device 38 was fabricated by the vacuum deposition method in the same manner as the light-emitting devices 2 to 5 described above. The details of the structure of the light-emitting device are shown in Tables 1 to 4, so the details of the fabrication method are omitted. In Tables 1 to 4, the value represented by x1 is as shown in Table 5, and the value represented by x2 is as shown in Table 6. The values ​​that can be obtained are shown in Table 6.

[0420] Comparative light-emitting devices 1, 6, 11, 16, 20, 25, 29 and comparative light-emitting device 34 were The light-emitting device does not include a fluorescent material in the optical layer 130. The phosphorescent material contained therein emits light. These light-emitting devices are phosphorescent. A light-emitting device in which the material acts as a guest material (energy acceptor) and phosphorescence As a comparative example of a light-emitting device according to one embodiment of the present invention in which a conductive material functions as an energy donor, showed.

[0421] Light emitting device 2 to light emitting device 5, light emitting device 7 to light emitting device 10, light emitting device light emitting device 12 to light emitting device 15, light emitting device 21 to light emitting device 24, light emitting device 2 The light emitting devices 6 to 28 and the light emitting devices 30 to 33 are light emitting devices according to an embodiment of the present invention. The light-emitting device includes a fluorescent material having a protecting group in each of the light-emitting layers 130, 2t The compound has a structure of Bu-ptBuDPhA2Anth. Therefore, the compound has a structure of a light-emitting device exhibiting fluorescent light. In addition, the comparative light-emitting devices 35 to 38 also have the light-emitting layer 130. The fluorescent material having a protecting group at the end is a fluorescent material having 2tBu-ptBuDPhA2Anth. It is a light emitting device.

[0422] In the light-emitting devices 2 to 5, the phosphorescent material having a five-membered ring is Ir(mpp tz-diBuCNp)3 in the light-emitting devices 7 to 10, As a phosphorescent material, Ir(mpptz-diPrp)3 is used for the light-emitting device 12 to the light-emitting device In VICE 15, Ir(Mptz1-mp)3 was used as a phosphorescent material with a five-membered ring. In the light-emitting device 17 to the light-emitting device 19, Ir(pb In the light-emitting devices 20 to 24, As the photo-sensitive material, fac-Ir(pbi-diBup)3 is used as the light-emitting device 26. In device 28, the phosphorescent material having a five-membered ring was Ir(pni-diBup)2(m dppy) as a phosphorescent material having a five-membered ring in light-emitting devices 30 to 33. The phosphorus ions with five-membered rings mentioned above are used as the cations. The phosphorescent material is an example of a phosphorescent material having a triazole skeleton or an imidazole skeleton. Comparative light-emitting devices 35 to 38 are made of phosphorescent materials that do not have a five-membered ring structure. The light-emitting device according to one embodiment of the present invention uses Ir(ppy)3, which is a material for the light-emitting device. It was made to compare the properties.

[0423] In addition, mPCCzPTzn-02 and PCCP form an exciplex, 4,6 mCzP2Pm and PCCP form an exciplex.

[0424] <Light-emitting device characteristics> Next, the light-emitting devices 2 to 5, 7 to 9, 10, light emitting device 12 to light emitting device 15, light emitting device 17 to light emitting device 1 9, light emitting device 21 to light emitting device 24, light emitting device 26 to light emitting device 28, and light-emitting devices 30 to 33, and comparative light-emitting devices 1, 6, 11, 16, and 20 The characteristics of the light-emitting devices 25, 29 and comparative light-emitting devices 34 to 38 were measured. A color luminance meter (Topcon, BM-5A) was used to measure the luminance and CIE chromaticity. A multichannel spectrometer (Hamamatsu Photonics, PMA-11) was used to measure the optical spectrum. was used.

[0425] Light emitting device 2 to light emitting device 5, light emitting device 7 to light emitting device 10, light emitting device light emitting device 12 to light emitting device 15, light emitting device 17 to light emitting device 19, light emitting device 2 1 to light emitting device 24, light emitting device 26 to light emitting device 28 and light emitting device 30 to light-emitting device 33, comparative light-emitting devices 1, 6, 11, 16, 20, 25, 29, and comparative The external quantum efficiency-luminance characteristics of the comparative light-emitting device 34 to the comparative light-emitting device 38 are shown in FIGS. , 18, 20, 22, 24, 26, and 28, respectively. Optical device 5, light emitting device 7 to light emitting device 10, light emitting device 12 to light emitting device light emitting device 15, light emitting device 17 to light emitting device 19, light emitting device 21 to light emitting device 2 4. Light emitting devices 26 to 28 and light emitting devices 30 to 33 , Comparative Light-Emitting Devices 1, 6, 11, 16, 20, 25, 29, and Comparative Light-Emitting Device 34 The light emitting device 38 is 2.5 mA / cm 2 When a current is applied at a current density of The electroluminescence spectra are shown in Figures 15, 17, 19, 21, 23, 25, 27, and 29, respectively. The measurements of each light-emitting device were carried out at room temperature (an atmosphere maintained at 23°C).

[0426] Also, 1000cd / m 2 Light emitting devices 2 to 5, Light emitting device 7 to light emitting device 10, light emitting device 12 to light emitting device 15, light emitting device 1 7 to light emitting device 19, light emitting device 21 to light emitting device 24, light emitting device 26 Light-emitting device 28, light-emitting device 30 to light-emitting device 33, comparative light-emitting device 1, 6, 11, 16, 20, 25, 29 and Comparative Light-Emitting Device 34 to Comparative Light-Emitting Device 38 The device characteristics are shown in Tables 7 and 8.

[0427] [Table 7]

[0428] [Table 8]

[0429] From energy donor (phosphorescent material with five-membered ring structure) to energy acceptor ( Energy transfer to fluorescent materials with protective groups As shown in FIG. 15, the emission spectra of the light-emitting devices 2 to 5 have a peak The length is about 528 nm and the half-width is about 62 nm. The emission spectrum of comparative light-emitting device 1 was is Ir(mptz-di) with a peak wavelength of 492 nm and a half-width of 67 nm. Thus, the light-emitting device according to one embodiment of the present invention It was found that energy transfer occurs from the phosphorescent material to the fluorescent material.

[0430] As shown in FIG. 17, the emission spectra of the light-emitting devices 7 to 10 have peaks The wavelength is about 530 nm and the half-width is about 66 nm. 2tBu-ptBuDPh The emission spectrum of comparative light-emitting device 6 was The peak wavelength is 508 nm and the half-width is 85 nm. Therefore, in the light-emitting device according to one embodiment of the present invention, It was found that energy transfer occurred from the phosphorescent material to the fluorescent material.

[0431] As shown in FIG. 19, the emission spectra of the light-emitting devices 12 to 15 are The wavelength is about 529 nm and the half-width is about 64 nm. The emission spectrum of comparative light-emitting device 11 was The spectrum is Ir(Mptz1) with a peak wavelength of 502 nm and a half-width of 91 nm. Therefore, in the light-emitting device according to one embodiment of the present invention, It was found that energy transfer occurs from the phosphorescent material to the fluorescent material.

[0432] As shown in FIG. 21, the emission spectrum of the comparative light-emitting device 16 has a maximum peak wavelength of 51 3 nm and the half-width is 64 nm, derived from Ir(pbi-diBuCNp)3 The emission spectrum of the light-emitting device 17 was 100% larger than that of the comparative light-emitting device 16. This is different from the spectrum of Ir(pbi-diBuCNp)3. Both the emission from 2tBu-ptBuDPhA2Anth and the emission from 2tBu-ptBuDPhA2Anth were observed. Therefore, it is understood that fluorescent light is emitted from the light-emitting device 17. The emission spectrum of the optical device 18 and the light-emitting device 19 has a peak wavelength of about 535 nm. The half-width is about 69 nm, which is derived from 2tBu-ptBuDPhA2Anth. Therefore, in the light-emitting device according to one embodiment of the present invention, It was found that energy transfer occurs from the fluorescing material to the fluorescent material.

[0433] As shown in FIG. 23, the emission spectrum of the comparative light-emitting device 20 has a maximum peak wavelength of 50 8 nm, and the half-width is 64 nm, derived from fac-Ir(pbi-diBup)3 The emission spectrum of the light-emitting device 21 was the same as that of the comparative light-emitting device 20. This is due to the fact that the spectrum is different from that of fac-Ir(pbi-diBup)3. Both the emission from 2tBu-ptBuDPhA2Anth and the emission from 2tBu-ptBuDPhA2Anth were observed. This is because, it is understood that fluorescent light is emitted from the light-emitting device 21. The emission spectra of the light-emitting devices 22 to 24 have a peak wavelength of 538 nm. nm, and the half-width is about 69 nm. Thus, in the light-emitting device according to one embodiment of the present invention, phosphorescence It was found that energy transfer occurred from the emissive material to the fluorescent material.

[0434] As shown in FIG. 25, the emission spectrum of the comparative light-emitting device 25 has a maximum peak wavelength of 52 5 nm and half-width 73 nm, Ir(pni-diBup)2(mdppy) The emission spectrum of the light-emitting device 26 was similar to that of the comparative light-emitting device 25. This is different from the emission spectrum of Ir(pni-diBup)2(mdpp Both the luminescence from 2tBu-ptBuDPhA2Anth and the luminescence from 2tBu-ptBuDPhA2Anth were This is because the fluorescent light is observed. In addition, the emission spectra of the light-emitting devices 27 and 28 have peaks The wavelength is about 535 nm and the half-width is about 69 nm. 2tBu-ptBuDPh Thus, the light-emitting device according to one embodiment of the present invention exhibited green light emission originating from A2Anth. It has been found that energy transfer occurs from the phosphorescent material to the fluorescent material.

[0435] As shown in FIG. 27, the emission spectrum of the comparative light-emitting device 29 has a maximum peak wavelength of 50 0 nm and the half-width is 59 nm. The emission spectrum of the light-emitting device 30 was 100% larger than that of the comparative light-emitting device 29. This is different from the 2tB This is because both the luminescence from u-ptBuDPhA2Anth and the luminescence from u-ptBuDPhA2Anth were observed. It can be seen that fluorescent light is emitted from the light-emitting device 29. The emission spectra of the light emitting device 31 to the light emitting device 33 have a peak wavelength of about 536 nm. The green light derived from 2tBu-ptBuDPhA2Anth has a half-width of about 65 nm. Thus, in the light-emitting device according to one embodiment of the present invention, a fluorescent material was produced from a phosphorescent material. It was found that energy transfer to the material occurred.

[0436] As shown in FIG. 29, the emission spectrum of the comparative light-emitting device 34 has a maximum peak wavelength of 51 The emission from Ir(ppy)3 was 7 nm and had a half-width of 70 nm. In addition, the emission spectra of the comparative light-emitting devices 35 to 38 have peak wavelengths of 535nm, half width is around 69nm, 2tBu-ptBuDPhA2A It showed green luminescence originating from nth.

[0437] Light emitting device 2 to light emitting device 5, light emitting device 7 to light emitting device 10, light emitting device light emitting device 12 to light emitting device 15, light emitting device 17 to light emitting device 19, light emitting device 2 1 to light emitting device 24, light emitting device 26 to light emitting device 28 and light emitting device 30 Although the light-emitting device 33 shows light emission originating from a fluorescent material, As shown in Figs. 18, 20, 22, 24, 26, Tables 7 and 8, Even in light-emitting devices with high concentrations of 2tBu-ptBuDPhA2Anth, Both devices showed high luminous efficiency exceeding 14% in external quantum efficiency. Light emitting device 2 to light emitting device 5, light emitting device 7 to light emitting device 1, 0, light emitting device 12 to light emitting device 15, light emitting device 17 to light emitting device 19, Light emitting devices 21 to 24, light emitting devices 26 to 28, and The optical device 30 to the light-emitting device 33 are superior to the comparative light-emitting device 37 at any concentration. Also, the external quantum efficiency was high.

[0438] Singlet excitations are generated by the recombination of carriers (holes and electrons) injected from a pair of electrodes. If the probability of generating electrons is a maximum of 25%, and the light extraction efficiency to the outside is set to 30%, The external quantum efficiency of the fluorescent light-emitting device is a maximum of 7.5%. to light emitting device 5, light emitting device 7 to light emitting device 10, light emitting device 12 to light emitting device device 15, light emitting device 21 to light emitting device 24, light emitting device 26 to light emitting device In the light-emitting devices 28 and 30 to 33, the external quantum efficiency is 7.5 This is because the carriers (holes and In addition to the emission from singlet excitons generated by the recombination of electrons, emission from triplet excitons This is because the light emitted from the fluorescent material originates from the energy transfer from the In the light-emitting device according to one embodiment of the present invention, a fluorescent material having a protecting group and a compound having a five-membered ring skeleton are By using a phosphorescent material that emits triplet excitons, the non-radiative deactivation of triplet excitons is suppressed and the emission layer emits triplet excitons. Both the singlet and triplet excitation energies generated are efficient for luminescence of fluorescent materials. It can be said that it has been converted well.

[0439] <Overlap between the absorption spectrum of a fluorescent material and the emission spectrum of a phosphorescent material with a five-membered ring> Next, the absorption spectrum of the fluorescent material 2tBu-ptBuDPhA2Anth and each The relationship between the EL emission spectrum and the phosphorescent material used in the light-emitting device was investigated. The results are shown in Figure 1. 30 to 36.

[0440] As described above, the comparative light-emitting devices 1, 6, 11, 16, 20, 25, and 29 each have an emission The light emission from the phosphorescent material used in the layer is shown in FIG. 30 to FIG. 36. The optical spectrum and the absorption spectrum of 2tBu-ptBuDPhA2Anth overlap. Therefore, the phosphorescent material and 2tBu-ptBuDPhA2An When both 2tBu-ptBuDPhA2Anth were used, the phosphorescence of each material was As described above, the light-emitting device according to one embodiment of the present invention has a high This shows the luminous efficiency. In other words, the deactivation of triplet excitons in the light-emitting layer that can occur in normal fluorescent elements. This is the effect of using a fluorescent material having a protecting group. In addition, the use of phosphorescent materials with five-membered rings has improved the regeneration of carriers in fluorescent materials. The binding is suppressed, and further, triplet excitation from the phosphorescent material to the fluorescent material by the Dexter mechanism is This is the effect of suppressing the energy transfer of triplet excitons and the deactivation of triplet exciton energy.

[0441] <Changes in external quantum efficiency due to guest material concentration> Figure 37 shows the relationship between the guest material concentration and the external quantum efficiency in light-emitting devices using each phosphorescent material. As shown in FIG. 37, the light-emitting device according to one embodiment of the present invention using a phosphorescent material having a five-membered ring The paper presents a comparative light-emitting device using Ir(ppy)3, a phosphorescent material that does not have a five-membered ring structure. Compared with the cases 34 to 38, the decrease in external quantum efficiency with increasing concentration of the fluorescent material is suppressed. This is because a guest material having a protective group is used in the light-emitting layer, and a five-membered By using phosphorescent materials with rings, the Dexter mechanism from the host material to the guest material can be realized. The energy transfer of triplet excitation energy and the deactivation of triplet excitation energy are suppressed. In addition, by increasing the concentration of the guest material, the host material is converted into the guest material. The excitation energy can be efficiently transferred to the material via the Förster mechanism. Therefore, both triplet excitation energy and singlet excitation energy in the light-emitting layer are converted into light emission energy of the fluorescent material. This is because the light-emitting device according to one embodiment of the present invention can efficiently convert the light into the electron transport material. By using this method, it is possible to obtain a light-emitting device with a high guest material concentration and high luminous efficiency. I found out that...

[0442] In addition, the light-emitting devices using Ir(mpptz-diPrp)3 and Ir(Mptz1-mp)3 It was also shown that the luminescence efficiency could be improved by increasing the concentration of the guest material.

[0443] <Reliability measurement of light-emitting devices> Next, light emitting device 2 to light emitting device 5, light emitting device 7 to light emitting device 10, Light emitting device 12 to light emitting device 15, light emitting device 17 to light emitting device 19, light emitting device Light emitting device 21 to light emitting device 24, light emitting device 26 to light emitting device 28 and light emitting device Light-emitting devices 30 to 33, and comparative light-emitting devices 1, 6, 11, 16, 20, 25, A constant current drive test was conducted at 2.0 mA for the 29. The results are shown in Figures 38 to 44. 38 to 44 show that increasing the guest material concentration improves reliability. This is because increasing the concentration of the guest material allows the excitation energy in the light-emitting layer to be efficiently transferred to the guest. This suggests that the increase in the guest material concentration is responsible for the conversion of the luminescence of the material. The triplet excitation energy is then transferred from the host material to the guest material via the Förster mechanism. This suggests that the energy transfer rate can be increased.

[0444] Here, in the light-emitting layer, energy transfer from the energy donor to the guest material, i.e. The energy transfer involved in luminescence competes with quenching processes caused by impurities and degradation products. Therefore, in order to obtain a reliable light-emitting device, it is necessary to control the energy transfer related to light emission. It is important to increase speed.

[0445] <Fluorescence lifetime measurement of light-emitting devices> Next, to investigate the effect of guest material concentration on the emission rate, we developed the light-emitting device 2. to light emitting device 5, light emitting device 7 to light emitting device 10, light emitting device 12 to light emitting device The fluorescence lifetimes of the device 15 and the comparative light-emitting devices 1, 6, and 11 were measured. A picosecond fluorescence lifetime measurement system (Hamamatsu Photonics) was used. To measure the lifetime of the fluorescence emission in the light-emitting device, a rectangular pulse voltage was applied to the light-emitting device. The decaying light emission from the voltage drop was measured in time resolution using a streak camera. The S / S voltage is applied at a frequency of 10 Hz, and the data measured repeatedly is integrated to obtain the S / S The data obtained had a high N ratio. The measurements were performed at room temperature (300K), and the luminance of the light-emitting device was 10 00cd / m 2 Apply a pulse voltage of around 3V to 4V so that the applied pulse Time width is 100μs, negative bias voltage is -5V (when element drive is OFF), measurement time range is The measurement was performed under the condition of 10 μsec. The measurement results are shown in Figures 49 to 51. In the graph, the vertical axis represents the state in which carriers are steadily injected (when the pulse voltage is ON). The horizontal axis indicates the elapsed time from the falling edge of the pulse voltage. Indicates the interval.

[0446] The attenuation curves shown in Figures 49 to 51 were fitted with an exponential function. From the light-emitting devices 2 to 5 and the light-emitting devices 7 to 10, The luminescence has a fast fluorescence component of less than 0.4 μs and a delayed fluorescence component of about 2 μs. The light emitting device 12 and the light emitting device 15 emit fluorescent components with a fast response of less than 0.4 μs and fluorescent components with a fast response of about 4 μs. It was found that the luminescence had a delayed fluorescent component. When the fluorescent material is added, the proportion of the early fluorescent component increases as the concentration of the fluorescent material increases, while the proportion of the delayed fluorescent component increases. In addition, the comparative light-emitting device 1 was found to have a low emission rate due to the phosphorescent material. It exhibits light emission having an early fluorescent component of 0.5 μs or less and a delayed fluorescent component of about 4 μs, Comparative light-emitting device 6 and comparative light-emitting device 11 exhibited emission from a phosphorescent material, and It was found that the light emitted had a fast fluorescence component of less than μs and a delayed fluorescence component of about 2 μs. Ta.

[0447] From these findings, it is believed that the emission rate can be increased by adding a fluorescent material as a guest material to the light-emitting layer. It can be seen that the emission rate of the fast fluorescent component originating from the fluorescent material increases. Here, the light-emitting devices 2 to 5 and the light-emitting devices 7 to As described above, the light-emitting devices 10, 12, and 15 each include a fluorescent material. Even light-emitting devices with high material concentrations show high external quantum efficiency. In one embodiment of the light-emitting device, high light emission can be achieved even if the proportion of light emission from the fluorescent material increases. Therefore, in the light-emitting device of one embodiment of the present invention, Triplet excitation energy transfer from the material to the guest material via the Dexter mechanism This allows the concentration of guest materials to be increased and the deactivation of triplet excitation energy to be suppressed. This allows the efficiency of the excitation energy transfer by the Förster mechanism to be improved. Therefore, in the light-emitting device according to one embodiment of the present invention, the light-emitting layer To efficiently utilize both the singlet excitation energy and the triplet excitation energy in the can be done.

[0448] As shown in Figs. 49 to 51, in order to increase the energy transfer rate, It is preferable to increase the concentration of the guest material in the light-emitting device according to one embodiment of the present invention. While suppressing the energy transfer by the - mechanism, the energy transfer rate by the Förster mechanism is increased. By increasing the concentration of fluorine, and by reducing the effect of competition with the quenching process, good luminescence efficiency can be achieved. It is possible to obtain a light emitting device having good reliability while maintaining the above characteristics. In the case of the light-emitting device, phosphorescence is observed, and therefore the emission lifetime is long. Since the emission is fluorescent, the emission lifetime is short. Therefore, the effect of competition with the quenching process described above is small. As described above, the light-emitting device of one embodiment of the present invention can be reduced in the concentration of the guest material. As a result, a light emitting device with good luminous efficiency and reliability can be obtained. EXAMPLES

[0449] In this example, a light-emitting device according to one embodiment of the present invention different from that in Example 1 and a comparative light-emitting device The fabrication example of the light-emitting device and the characteristics of the light-emitting device are described below. The configuration is the same as in Figure 1A. The details of the device structure are shown in Table 9. The structures and abbreviations are shown below. For other organic compounds, see the previous examples and embodiments. Just refer to it.

[0450] [ka]

[0451] [Table 9]

[0452] [Table 10]

[0453] <Preparation of Comparative Light-Emitting Device 39 and Light-Emitting Devices 40 to 43> The comparative light-emitting device 39 and the light-emitting devices 40 to 43 are the same as the light-emitting devices 2 to 41 shown above. The light-emitting devices were fabricated by vacuum deposition in the same manner as the optical device 5. The details of the structures of the light-emitting devices are shown in Tables 9 and 10. The details of the preparation method are omitted here because they are as shown in Table 10. The values ​​are shown in Table 10.

[0454] In addition, the comparative light-emitting device 39 uses the phosphorescent material Ir(pbi-diBuCNp)3 as an emitter. This paper describes a method in which a phosphorescent material acts as an energy donor. This is shown as a comparative example of a light-emitting device according to one embodiment of the present invention.

[0455] <Light-emitting device characteristics> Next, the characteristics of the comparative light-emitting device 39 and the light-emitting devices 40 to 43 prepared above were measured. The measurement method was the same as in Example 1.

[0456] FIG. 5 shows the external quantum efficiency-luminance characteristics of the comparative light-emitting device 39 and the light-emitting devices 40 to 43. 2. Comparative light-emitting device 39 and comparative light-emitting devices 40 to 43 are shown in FIG. 2.5mA / cm 2 FIG. 53 shows the electroluminescence spectrum when a current was passed at a current density of 1000 .mu.m. The measurements of each light-emitting device were carried out at room temperature (an atmosphere maintained at 23° C.).

[0457] Also, 1000cd / m 2 Comparative light-emitting device 39 and comparative light-emitting device The characteristics of devices 40 to 43 are shown in Table 11.

[0458] [Table 11]

[0459] From energy donor (phosphorescent material with five-membered ring structure) to energy acceptor ( Energy transfer to fluorescent materials with protective groups As shown in FIG. 53, the emission spectra of the light-emitting devices 40 to 43 have a peak wavelength of 52 0nm, and the half-width is around 69nm. 2,6tBu-mmtBuDPhA2 The emission spectrum of comparative light-emitting device 39 was is Ir(pbi-diBu) with a peak wavelength of 513 nm and a half-width of 63 nm. Therefore, in the light-emitting device according to one embodiment of the present invention, It was found that energy transfer occurs from the phosphorescent material to the fluorescent material.

[0460] Although light-emitting devices 40 to 43 show emission from fluorescent materials, FIG. As shown in Table 52 and Table 11, even in light-emitting devices with high concentrations of fluorescent material, Both of the devices showed high luminous efficiency exceeding 15% in external quantum efficiency. In light-emitting devices, fluorescent materials with protective groups and phosphorescent materials with five-membered ring structures are used. This suppresses the non-radiative deactivation of triplet excitons and increases the radiation-induced decay of singlet excitons generated in the light-emitting layer. Both the energy and triplet excitation energy are efficiently converted into light emission from the fluorescent material. I can say.

[0461] <Reliability measurement of light-emitting devices> Next, the comparative light-emitting device 39 and the light-emitting devices 40 to 43 were subjected to a constant current of 2.0 mA. A drive test was performed. The results are shown in Figure 54. As shown in Figure 54, when the guest material concentration was increased, the signal This is because increasing the concentration of the guest material in the emitting layer improves the reliability. This suggests that the excitation energy can be efficiently converted into the emission of the guest material. In other words, by increasing the concentration of the guest material, the Förster mechanism from the host material to the guest material can be promoted. This suggests that the energy transfer rate of triplet excitation energy can be increased by will be done.

[0462] <Fluorescence lifetime measurement of light-emitting devices> Next, to investigate the difference in the emission rate depending on the concentration of the guest material, a comparative emission device was used. The fluorescence lifetime of the light emitting devices 39 and 40 to 43 was measured. The results are shown in Figure 55.

[0463] From Figure 55, the ratio of fluorescent components with faster emission speed increases as the concentration of fluorescent material (guest material) increases. It was found that the proportion of the delayed fluorescent component increased and the proportion of the delayed fluorescent component decreased. By adding a fluorescent material to the light-emitting layer as a light source, the light emission speed increases and the light emission caused by the fluorescent material It can be seen that the proportion of the emission of the faster fluorescent component increases.

[0464] Here, the light-emitting devices 40 to 43 according to one embodiment of the present invention are as described above. Even light-emitting devices with high concentrations of fluorescent materials show high external quantum efficiency. In the light-emitting device according to one embodiment of the present invention, even if the proportion of light emitted from the fluorescent material increases, It can be seen that the light-emitting device of one embodiment of the present invention has high light-emitting efficiency. , triplet excitation energy from the host material to the guest material by the Dexter mechanism This suppresses the transfer of valence energy and the deactivation of triplet excitation energy, so the concentration of guest materials is increased. This increases the energy of the excitation energy by the Förster mechanism. This suggests that the electron transfer efficiency can be improved. Both singlet and triplet excitation energies in the light-emitting layer are efficiently utilized for light emission. It is possible.

[0465] (Reference example 1) In this reference example, the fluorescent material having a protecting group used in Example 1, 2tBu-ptBu The synthesis method of DPhA2Anth will be described.

[0466] 1.2 g (3.1 mmol) of 2-tert-butylanthracene and 1.8 g (6.4 mmol) of mmol) of bis(4-tert-butylphenyl)amine and 1.2 g (13 mmol) ) of sodium t-butoxide and 60 mg (0.15 mmol) of 2-dicyclohexane Silphosphino-2',6'-dimethoxy-1,1'-biphenyl (abbreviation: SPhos) The mixture was placed in a 200 mL three-neck flask and the inside of the flask was replaced with nitrogen. Mesitylene was added, the mixture was degassed under reduced pressure, and then 40 mg (70 μmol) of Bis(dibenzylideneacetone)palladium(0) was added, and the mixture was stirred for 1 The mixture was stirred at 70° C. for 4 hours.

[0467] After stirring, 400 mL of toluene was added to the resulting mixture, and then Florisil (Wako Pure Chemical Industries, Ltd.) was added. Catalog number: 066-05265), Celite (Wako Pure Chemical Industries, Ltd., Catalog number: 537-02305), and suction-filtered through aluminum oxide to obtain the filtrate. The obtained filtrate was concentrated to give a brown solid.

[0468] The solid was subjected to silica gel column chromatography (eluent: hexane:toluene 9:1 The yellow solid was purified by toluene and hexane to obtain the target yellow solid. When recrystallized from methanol and ethanol, 1.5 g of the desired yellow solid was obtained in 61% yield. The synthesis scheme is shown in (A-1) below.

[0469] [ka]

[0470] The resulting yellow solid (1.5 g) was purified by train sublimation. The purification was carried out by heating the yellow solid at 315°C for 15 hours under a pressure of 4.5 Pa. Thereafter, the target product, a yellow solid, was obtained in an amount of 1.3 g with a recovery rate of 89%.

[0471] In addition, the yellow solid obtained in this synthesis 1 The results of H-NMR are shown below. 1 The H-NMR charts are shown in Figures 45 and 46. Note that Figure 45B shows the 6 H-NMR chart of Figure 45A. FIG. 46 is an enlarged view of the range from 0.5 ppm to 9.0 ppm. This is an enlarged view of the range from 0.5 ppm to 2.0 ppm. From this result, it is clear that the target 2t It was found that Bu-ptBuDPhA2Anth was obtained.

[0472] 1 H-NMR (CDCl3,300MHz):σ=8.20-8.13(m, 2H), 8 .12(d, J=8.8Hz, 1H), 8.05(d, J=2.0Hz, 1H), 7.4 2(dd, J=9.3Hz, 2.0Hz, 1H), 7.32-7.26(m, 2H)7. 20(d, J=8.8Hz, 8H), 7.04(dd, J=8.8Hz, 2.4Hz, 8 H), 1.26(s, 36H), 1.18(s, 9H).

[0473] (Reference example 2) In this reference example, Ir(pni This section explains how to synthesize diBup3.

[0474] <Step 1: Synthesis of 2,6-diisobutylaniline> 2,6-Dichloroaniline 100g (617mmol), Isobutylboronic acid 230g (2256mmol), potassium phosphate tripotassium phosphate 479g (2256mmol), 2-dicyclo Hexylphosphino-2',6'-dimethoxybiphenyl (S-phos) 10g (24 .7 mmol) and 3000 mL of toluene were placed in a 5000 mL three-neck flask. The air in the flask was replaced with nitrogen, and the mixture was degassed by stirring while reducing the pressure inside the flask. Add 11 g (11.5 mmol) of bis(dibenzylideneacetone)dipalladium(0), The mixture was stirred at 120° C. for 12 hours under a nitrogen stream. After a predetermined time had elapsed, the resulting reaction solution was filtered by suction. The filtrate was purified by extraction with toluene. The product was purified by column chromatography using a 15:1 mixture of hexane and toluene as the developing solvent. The obtained fraction was concentrated to obtain the target product as a black oil (79 g, yield 62%). %. The synthesis scheme of step 1 is shown in the following formula (B-1).

[0475] [ka]

[0476] <Step 2: Synthesis of 2-nitronaphthalene-1-trifluoromethanesulfonate> 35g (182mmol) of 2-nitro-1-naphthol, 500mL of dehydrated dichloromethane Put 51 mL (365 mmol) of triethylamine into a 1000 mL three-neck flask and The inside of the flask was replaced with nitrogen and cooled to 0°C. (abbreviation: TfO) 40mL (243mmol) was added dropwise, stirred at 0℃ for 1 hour, and then cooled to room temperature. The mixture was stirred for 20 hours. After the specified time had elapsed, 300 mL of water and 30 mL of 1M hydrochloric acid were added to the mixture. The mixture was then purified by extraction with dichloromethane. The extract was then purified by silica gel column chromatography. The fraction was concentrated to give the target product, a yellow oil. The product was obtained in an amount of 47 g and a yield of 80%. The synthesis scheme of step 2 is shown in the following formula (B-2). .

[0477] [ka]

[0478] Step 3: N-(2,6-diisobutylphenyl)-2-nitro-1-naphthalene Synthesis of Mine> 30 g (146 mmol) of 2,6-diisobutylaniline synthesized in step 1, 47 g (1 g) of 2-nitronaphthalene-1-trifluoromethanesulfonate synthesized in step 2 46 mmol), cesium carbonate 81 g (248 mmol), toluene 750 mL, The flask was replaced with nitrogen and the flask was stirred while the pressure was reduced. After degassing, 4.8 g (11.7 mmol) of S-phos and Tris( Add 2.7 g (2.9 mmol) of dibenzylideneacetone dipalladium(0) and evaporate with nitrogen. The mixture was stirred at 130° C. for 28 hours under airflow. After the predetermined time had elapsed, the reaction mixture was diluted with toluene. The extract was then purified by silica gel column chromatography. The developing solvent used was hexane:ethyl acetate = 15:1. The product was concentrated to give a yellow oil (13 g, 23% yield). The synthesis scheme for step 3 is shown below. As shown in formula (B-3).

[0479] [ka]

[0480] Step 4: N-(2,6-diisobutylphenyl)-1,2-naphthalenediamine Synthesis> N-(2,6-diisobutylphenyl)-2-nitro-1-naphthalene synthesized in step 3 13 g (34 mmol) of ethyl amine, 6.1 mL (0.34 mol) of water, 40 mL of ethanol 0 mL of the mixture was placed in a 1000 mL three-neck flask and stirred. 2g (0.17mol) was added and stirred at 80°C for 5 hours under a nitrogen stream. The resulting reaction mixture was poured into 500 mL of 2M aqueous sodium hydroxide solution and stirred at room temperature for 2 hours. The precipitate was filtered by suction and washed with chloroform to obtain a filtrate. The liquid was purified by extraction with chloroform. The developing solvent was hexane:ethyl acetate=15:1. The fraction was concentrated to give 9.5 g of the target product as a black oil in a yield of 81%. The synthetic scheme of step 4 is shown in formula (B-4) below.

[0481] [ka]

[0482] <Step 5; 1-(2,6-diisobutylphenyl)-2-phenyl-1H-naphthyl [ Synthesis of 1,2-d]imidazole (abbreviation: Hpni-diBup) N-(2,6-diisobutylphenyl)-1,2-naphthalenediamide synthesized in step 4 9.5g (27mmol) amine, 100mL acetonitrile, 2.9g benzaldehyde (27 mmol) was placed in a 300 mL eggplant flask and stirred at 100°C for 6 hours. Add 0.044 g (0.274 mmol) of iron(III) chloride to the mixture and heat at 100°C for 16 hours. After a predetermined time had elapsed, the reaction mixture was extracted with ethyl acetate. Add 100 mL of toluene and 10 g of manganese(IV) oxide to 300 mL of eggplant flask. The reaction mixture was poured into a celite container and stirred at 130° C. for 7 hours. (Wako Pure Chemical Industries, Ltd., Catalog number: 537-02305) / Florisil (Wako Pure Chemical Industries, Ltd. Yaku Kogyo Co., Ltd., Catalog Number: 066-05265) / Suction through aluminum oxide The filtrate was concentrated to give an oily product. The oily product was purified by silica gel column chromatography. The product was purified by chromatography using toluene as the developing solvent. The reaction mixture was concentrated to give the desired product as a white solid (7.9 g, 66% yield). The synthesis scheme is shown in the following formula (B-5).

[0483] [ka]

[0484] Step 6: Di-μ-chloro-tetrakis{2-[1-(2,6-diisobutylphenyl (1H-naphtho[1,2-d]imidazol-2-yl-κN3]phenyl-κC} Synthesis of diiridium(III) (abbreviation: [Ir(pni-diBup)2Cl]2) 1-(2,6-diisobutylphenyl)-2-phenyl-1H-naphthalene synthesized in step 5 Hpni-diBup 3.3g (7.7mm ol), iridium chloride monohydrate 1.6g (3.7mmol), 2-ethoxyethanol 30 mL of ethanol and 10 mL of water were placed in a 100 mL round-bottom flask, and the atmosphere in the flask was replaced with argon. By irradiating this reaction vessel with microwaves (2.45GHz, 100W) for 2 hours, After the reaction, the reaction solution was filtered by suction to obtain 2.8 g of the target yellow solid in a yield of 6. The synthesis scheme of step 6 is shown in the following formula (B-6).

[0485] [ka]

[0486] <Step 7; Tris{2-[1-(2,6-diisobutylphenyl)-1H-naphtho[ 1,2-d]imidazol-2-yl-κN3]phenyl-κC}iridium(III) Synthesis of (abbreviation: [Ir(pni-diBup)3]) Di-μ-chloro-tetrakis{2-[1-(2,6-di isobutylphenyl)-1H-naphtho[1,2-d]imidazol-2-yl-κN3 Phenyl-κC}diiridium(III) (abbreviation: [Ir(pni-diBup)2Cl 2) 2.0 g (0.92 mmol) and 150 mL of dichloromethane were added to a 500 mL three-neck flask. The mixture was placed in a flask and stirred under a nitrogen stream. A mixture of 0.72 g (2.8 mmol) and 150 mL of methanol was added dropwise, and the mixture was incubated for 3 h in a dark place. After stirring for 3 days, the reaction mixture was filtered through Celite. The mixture was concentrated to give 2.7 g of a yellow solid. 1-(2,6-diisobutylphenyl)-2-phenyl-1-isobutylphenyl H-naphtho[1,2-d]imidazole (abbreviation: Hpni-diBup) 1.6 g (3. 7 mmol) was placed in a 500 mL recovery flask and heated to reflux for 20 hours under a nitrogen stream. After the reaction for a certain time, the reaction mixture was suction filtered to obtain a solid. The obtained solid was dissolved in dichloromethane and The mixture was dissolved and filtered through Celite / neutral silica / Celite. The filtrate was concentrated. A solid was obtained by this procedure, and the obtained solid was purified by silica gel column chromatography. The developing solvent used was dichloromethane:hexane = 1:3. The obtained fraction was concentrated. The solid was recrystallized from ethyl acetate / hexane to give 1.1 g of the solid. The synthesis scheme is shown in the following formula (B-7).

[0487] [ka]

[0488] The obtained solid (1.1 g) was purified by train sublimation. The solid was heated at 340°C under conditions of pressure 2.6 Pa and argon flow rate 10.5 mL / min. The mixture was heated for 41 hours. After purification by sublimation, 0.93 g of a yellow solid was obtained with a recovery rate of 88%.

[0489] The proton NMR of the yellow solid obtained above ( 1 H-NMR measurements were performed. The values ​​shown are also shown below. 1 The H-NMR chart is shown in Figure 47. As shown in Figure 47, one embodiment of the present invention It was found that the organometallic complex Ir(pni-diBup)3 was obtained.

[0490] 1 H-NMR.δ(CD2Cl2):0.15(d,9H),0.39-0.42(m, 18H),0.59(d,9H),1.27-1.35(m,3H),1.78-1.8 6(m,3H),1.93-2.02(m,6H),2.33(d,6H),6.35- 6.40(m,6H),6.56-6.61(m,6H),7.04-7.07(m,6 H),7.16(t,3H),7.25(d,3H),7.30(t,3H),7.40 (d,3H),7.48(d,3H),7.63(t,3H),7.73(d,3H).

[0491] (Reference example 3) In this reference example, Ir(pni This article explains how to synthesize -diBup)2(mdppy).

[0492] <Step 1; Bis{2-[1-(2,6-diisobutylphenyl)-1H-naphtho[1 ,2-d]imidazol-2-yl-κN3]phenyl-κC}[2-(4-methyl-5 -phenyl-2-pyridyl-κN2)phenyl-κC]iridium(III) (abbreviation: [ Synthesis of Ir(pni-diBup)2(mdppy) [Ir(mdppy)2Cl]21.3g (0.9mmol), dichloromethane 180m The mixture was placed in a 500 mL three-neck flask and stirred under a nitrogen stream. A mixture of 0.7 g (2.7 mmol) of silver oromethanesulfonate and 35 mL of methanol After the reaction time, the reaction mixture was filtered through Celite. The filtrate was concentrated to give 1.9 g of a yellow solid. Methanol 30 mL, ethanol 30 mL, Hpni-diBup 1.6 g (3.6 mm ol) was placed in a 300 mL recovery flask and heated under reflux for 23 hours under a nitrogen stream. After the reaction, the reaction mixture was filtered under suction to remove insoluble matter, and the filtrate was concentrated to obtain a solid. 60 mL of 1-butanol was added to the solid, and the mixture was heated under reflux for 22 hours under a nitrogen atmosphere. After the reaction, the reaction mixture was filtered under suction to obtain a solid. The obtained solid was purified by silica gel column chromatography. The mixture was purified by chromatography using a 3:1 mixture of hexane and dichloromethane as the developing solvent. The obtained fraction was concentrated to give a solid. The obtained solid was dissolved in ethyl acetate. The product was recrystallized from methanol / hexane to give 0.20 g of a yellow solid in 9% yield. The scheme is shown in formula (C-1) below.

[0493] [ka]

[0494] The obtained solid (0.19 g) was purified by train sublimation. The obtained solid was heated at 320℃ under the conditions of a pressure of 2.5 Pa and an argon flow rate of 10.3 mL / min. The target yellow solid was purified by sublimation, weighing 0.14 g, with a recovery rate of 72%. Obtained in %.

[0495] The yellow solid obtained above 1 H-NMR measurement was performed. The values ​​obtained are shown below. 1 The H-NMR chart is shown in FIG. 48. As shown in FIG. 48, the organometallic complex of one embodiment of the present invention It was found that [Ir(pni-diBup)2(mdppy)] was obtained.

[0496] 1 H-NMR.δ(CD2Cl2):0.09-0.15(m,9H),0.29-0. 34(m,9H),0.40(t,1H),0.45(d,3H),0.51(d,3H ),1.18-1.24(m,1H),1.34-1.49(m,1H),1.70-1 .78(m,1H),1.88-2.09(m,6H),2.17-2.25(m,2H ),2.51(s,3H),6.30-6.40(m,3H),6.48(t,1H), 6.61-6.52(m,3H),6.64-6.69(m,2H),6.74-6.7 9(m,2H),6.83(t,1H),6.93-7.01(m,3H),7.08( t,1H),7.13-7.25(m,8H),7.34-7.51(m,6H),7. 57-7.73(m,4H),7.87(d,1H),7.94(s,1H),8.31 (s,1H).

[0497] (Reference example 4) In this reference example, the fluorescent material having a protecting group used in Example 2, 2,6tBu-mm The synthesis method of tBuDPhA2Anth will be described.

[0498] 1.1 g (2.5 mmol) of 2,6-di-tert-butylanthracene and 2.3 g (5.8 mmol) of bis(3,5-tert-butylphenyl)amine and 1.1 g ( 11 mmol) of sodium t-butoxide and 60 mg (0.15 mmol) of SP The mixture was placed in a 200 mL three-neck flask and the atmosphere in the flask was replaced with nitrogen. 1 mL of xylene was added, the mixture was degassed under reduced pressure, and 40 mg (70 μmol ) of bis(dibenzylideneacetone)palladium(0) was added and the mixture was cooled under a nitrogen stream. The mixture was stirred at 150° C. for 6 hours.

[0499] After stirring, 400 mL of toluene was added to the resulting mixture, followed by Florisil, Celite, The filtrate was filtered through aluminum oxide with suction to obtain a brown solid. Got it.

[0500] The solid was subjected to silica gel column chromatography (eluent: hexane:toluene=9: The yellow solid was purified by hexane and methanol. The product was recrystallized from ethanol to give 0.45 g of a yellow solid in a yield of 17%. The synthetic scheme of Step 1 is shown below (D-1).

[0501] [ka]

[0502] The resulting yellow solid (0.45 g) was purified by train sublimation. The purification was carried out by heating the yellow solid at 275°C for 15 hours under a pressure of 5.0 Pa. After purification, the target yellow solid was obtained in a yield of 0.37 g and a recovery rate of 82%.

[0503] In addition, the yellow solid obtained in step 1 above 1 The results of H-NMR measurements are shown below. Also, 1 The H-NMR charts are shown in Figures 56A, 56B, and 57. 56B is a chart showing an enlarged range from 6.5 ppm to 9.0 ppm in FIG. FIG. 57 shows an enlarged view of the range from 0.5 ppm to 2.0 ppm in FIG. 56A. This chart shows that 2,6tBu-mmtBuDPhA2Anth It was found that it was obtained.

[0504] 1 H-NMR (CDCl3,300MHz):σ=8.11(d, J=9.3Hz, 2H ), 7.92(d, J=1.5Hz, 1H), 7.34(dd, J=9.3Hz, 2.0 Hz, 2H), 6.96-6.95(m, 8H), 6.91-6.90(m, 4H), 1 .13-1.12(m,90H). [Explanation of symbols]

[0505] 100: EL layer, 101: electrode, 102: electrode, 106: light-emitting unit, 108: light-emitting unit knit, 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: light emitting layer, 130: light emitting layer, 131: compound, 13 2: Compound, 133: Compound, 134: Compound, 135: Compound, 150: Light-emitting device , 170: light-emitting layer, 250: light-emitting device, 301: guest material, 302: guest material, 310: luminophore, 320: protecting group, 330: host material, 601: source side driving circuit, 6 02: pixel section, 603: gate side driving circuit, 604: sealing substrate, 605: sealing material, 60 7: space, 608: wiring, 610: substrate, 611: switching TFT, 612: current Control TFT, 613: electrode, 614: insulator, 616: EL layer, 617: electrode, 618 : Light emitting device, 623: n-channel TFT, 624: p-channel TFT, 900: Mobile information terminal, 901: housing, 902: housing, 903: display unit, 905: hinge unit, 91 0: portable information terminal, 911: housing, 912: display unit, 913: operation button, 914: external Connection port, 915: Speaker, 916: Microphone, 917: Camera, 920: Camera, 9 21: Housing, 922: Display unit, 923: Operation buttons, 924: Shutter button, 926 : Lens, 1001: Substrate, 1002: Base 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, 102 4R: Electrode, 1024W: Electrode, 1025B: Lower electrode, 1025G: Lower electrode, 102 5R: Lower electrode, 1025W: Lower electrode, 1026: Partition wall, 1028: EL layer, 1029 : Electrode, 1031: Sealing substrate, 1032: Sealing material, 1033: Base material, 1034B: Coloring layer, 1034G: colored layer, 1034R: colored layer, 1036: overcoat layer, 1037 : Interlayer insulating film, 1040: Pixel section, 1041: Drive circuit section, 1042: Peripheral section, 1044 R: red pixel, 1044G: green pixel, 1044B: blue pixel, 1044W: white pixel, 2100: robot, 2101: illuminance sensor, 2102: microphone, 2103: top 2104: speaker, 2105: display, 2106: lower camera, 21 07: Obstacle sensor, 2108: Moving mechanism, 2110: Calculation device, 5000: Housing, 50 01: Display unit, 5002: Display unit, 5003: Speaker, 5004: LED lamp 500 6: connection terminal, 5007: sensor, 5008: microphone, 5012: support part, 50 13: Earphones, 5100: Cleaning robot, 5101: Display, 5102: Camera , 5103: brush, 5104: operation button, 5120: dust, 5140: portable electronic device 5150: portable information terminal, 5151: housing, 5152: display area, 5153: bending portion, 8501: Lighting device, 8502: Lighting device, 8503: Lighting device, 8504: Lighting device

Claims

1. A light-emitting device having a light-emitting layer between a pair of electrodes, the light-emitting layer comprises a first material and a second material; the first material is capable of converting triplet excitation energy into luminescence, and has a five-membered ring skeleton and a platinum group element; the second material is capable of converting singlet excitation energy into luminescence and has a luminophore and five or more protecting groups; the luminophore is a fused aromatic ring or a fused heteroaromatic ring; the five or more protecting groups each independently include one of an alkyl group having from 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having from 3 to 10 carbon atoms, or a trialkylsilyl group having from 3 to 12 carbon atoms; the T1 level of the first material is higher than the S1 level of the second material; A light emitting device, wherein an emission spectrum of the first material has an overlap with an absorption spectrum of the second material.

2. In claim 1, a light-emitting device, 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 device having a light-emitting layer between a pair of electrodes, the light-emitting layer comprises a first material and a second material; the first material is capable of converting triplet excitation energy into luminescence, and has a five-membered ring skeleton and a platinum group element; the second material is capable of converting singlet excitation energy into luminescence and has a luminophore and at least 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 the fused heteroaromatic ring, the four protecting groups each independently have any 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; the T1 level of the first material is higher than the S1 level of the second material; A light emitting device, wherein an emission spectrum of the first material has an overlap with an absorption spectrum of the second material.

4. A light-emitting device having a light-emitting layer between a pair of electrodes, the light-emitting layer comprises a first material and a second material; the first material is capable of converting triplet excitation energy into luminescence, and has a five-membered ring skeleton and a platinum group element; the second material is capable of converting singlet excitation energy into luminescence; 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 of the aryl groups in the two or more diarylamino groups independently has at least one protecting group; the protecting group is any 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; the T1 level of the first material is higher than the S1 level of the second material; A light emitting device, wherein an emission spectrum of the first material has an overlap with an absorption spectrum of the second material.

5. A light-emitting device having a light-emitting layer between a pair of electrodes, the light-emitting layer comprises a first material and a second material; the first material is capable of converting triplet excitation energy into luminescence, and has a five-membered ring skeleton and a platinum group element; the second material is capable of converting singlet excitation energy into luminescence and has 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 of the aryl groups in the two or more diarylamino groups independently has at least two protecting groups; the protecting group is any 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; the T1 level of the first material is higher than the S1 level of the second material; A light emitting device, wherein an emission spectrum of the first material has an overlap with an absorption spectrum of the second material.

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

7. A light-emitting device having a light-emitting layer between a pair of electrodes, the light-emitting layer comprises a first material and a second material; the first material is capable of converting triplet excitation energy into luminescence, and has a five-membered ring skeleton and a platinum group element; the second material is capable of converting singlet excitation energy into luminescence and has a luminophore and a plurality of protecting groups; the luminophore is a fused aromatic ring or a fused heteroaromatic ring; the protecting group is any 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; at least one of the atoms constituting the plurality of protecting groups is located directly 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 directly above the other face of the fused aromatic ring or the fused heteroaromatic ring; the T1 level of the first material is higher than the S1 level of the second material; A light emitting device, wherein an emission spectrum of the first material has an overlap with an absorption spectrum of the second material.

8. A light-emitting device having a light-emitting layer between a pair of electrodes, the light-emitting layer comprises a first material and a second material; the first material is capable of converting triplet excitation energy into luminescence, and has a five-membered ring skeleton and a platinum group element; the second material is capable of converting singlet excitation energy into luminescence and has a luminophore and two or more diphenylamino groups; the luminophore is a fused aromatic ring or a fused heteroaromatic ring; the condensed aromatic ring or the condensed heteroaromatic ring is bonded to the two or more diphenylamino groups; the phenyl groups in the two or more diphenylamino groups each independently have a protecting group at the 3-position and the 5-position; each of the protecting groups independently has 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; the T1 level of the first material is higher than the S1 level of the second material; A light emitting device, wherein an emission spectrum of the first material has an overlap with an absorption spectrum of the second material.

9. In any one of claims 1 to 8, The five-membered ring skeleton has any one of a pyrazole skeleton, an imidazole skeleton, and a triazole skeleton.

10. In claim 9, a nitrogen atom not involved in a double bond of the imidazole skeleton and the triazole skeleton has a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms;

11. A light-emitting device having a light-emitting layer between a pair of electrodes, the light-emitting layer comprises a first material and a second material; the first material is capable of converting triplet excitation energy into luminescence, and has a five-membered ring skeleton and a platinum group element; the five-membered ring skeleton has at least one of an imidazole skeleton or a triazole skeleton, a nitrogen atom not involved in a double bond of the imidazole skeleton and the triazole skeleton has a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms, the second material is capable of converting singlet excitation energy into luminescence and has a luminophore and two or more protecting groups; the luminophore is a fused aromatic ring or a fused heteroaromatic ring; the two or more protecting groups each independently have 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; the T1 level of the first material is higher than the S1 level of the second material; A light emitting device, wherein an emission spectrum of the first material has an overlap with an absorption spectrum of the second material.

12. In claim 10 or 11, The aromatic hydrocarbon group is a phenyl group.

13. In any one of claims 1 to 12, The light emitting device wherein the alkyl group is a branched chain alkyl group.

14. In claim 13, A light emitting device, wherein the branched alkyl group has a quaternary carbon.

15. In any one of claims 1 to 14, The fused aromatic ring or the fused heteroaromatic ring comprises any one of naphthalene, anthracene, fluorene, chrysene, triphenylene, tetracene, pyrene, perylene, coumarin, quinacridone, and naphthobisbenzofuran.

16. In any one of claims 1 to 15, A light-emitting device, wherein the emission spectrum of the first material overlaps with a longest wavelength absorption band of the absorption spectrum of the second material.

17. In any one of claims 1 to 16, A light-emitting device, wherein the concentration of the second material in the light-emitting layer is 2 wt % or more and 30 wt % or less.

18. A light emitting device according to any one of claims 1 to 17; An electronic device having at least one of a housing or a touch sensor.

19. A light emitting device according to any one of claims 1 to 17; A lighting device having at least one of a housing or a touch sensor.

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