Light-emitting device, electronic apparatus, and lighting device

Abstract

To provide a light-emitting device with high emission efficiency and high reliability.SOLUTION: There is provided a light-emitting device including a fluorescent light-emitting layer and a phosphorescent light-emitting layer. A host material used in the fluorescent light-emitting layer has a function of converting triplet excitation energy into light emission, and a guest material used in the fluorescent light-emitting layer emits fluorescence. The guest material has a molecular structure including a luminophore and a protecting group, and one molecule of the guest material includes five or more protecting groups. The introduction of the protecting groups into the molecule inhibits transfer of triplet excitation energy from the host material to the guest material by the Dexter mechanism. An alkyl group or a branched-chain alkyl group is used as the protecting group. The longest wavelength absorption band in the absorption spectrum of the guest material in the phosphorescent light-emitting layer has an overlap with the emission spectrum of the host material in the phosphorescent light-emitting layer.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, and Color phosphorescent devices have not yet been put to practical use. Light-emitting devices using fluorescent materials (fluorescent light-emitting devices) are being developed. Methods are being explored to improve the light-emitting efficiency of LEDs.

[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] Multi-color light-emitting devices, such as white light-emitting devices, are expected to be used in displays and other applications. The structure of the multicolor light-emitting device is a set of multiple electrodes between which are disposed different light-emitting colors. Devices containing a light-emitting layer are preferred. In this case, a phosphorescent material is preferred from the viewpoint of reliability and color purity. There is a demand for the development of light-emitting devices that combine a light-emitting layer containing a fluorescing material with a light-emitting layer containing a fluorescing material. .

[0013] One method for improving the luminous efficiency of a fluorescent layer in a light-emitting device is to use a host material and a gate In a fluorescent layer having a fluorescent material as a host material, triplet excitation of the host material is After converting the energy into singlet excitation energy, the singlet excitation energy is transferred to a fluorescent material. However, the triplet excitation energy of the host material is The process of conversion to singlet excited energy competes with the process of deactivation of triplet excited energy. Therefore, the triplet excitation energy of the host material is sufficiently converted to singlet excitation energy. The triplet excitation energy may be lost through, for example, fluorescence emission. In the layer, the host is placed in the lowest triplet excited energy level (T1 level) of the fluorescent material. A deactivation pathway is considered in which the triplet excitation energy of the material is transferred. The energy transfer does not contribute to light emission, leading to a decrease in the luminous efficiency of the fluorescent-emitting layer. The deactivation pathway can be suppressed by reducing the concentration of the fluorescent guest material. At the same time, the rate of energy transfer from the host material to the singlet excited state of the fluorescent material is also low. This leads to degradation and impurities that can easily cause quenching of light. The brightness is likely to decrease, leading to a decrease in reliability. In addition, the phosphorescent layer and the fluorescent layer are close to each other. In this case, the T1 level of the fluorescent material is the deactivation level of the triplet excitation energy of the phosphorescent layer. In other words, this can lead to a decrease in the luminous efficiency of the phosphorescent-emitting layer.

[0014] In one embodiment of the present invention, the triplet excitation energy of the host material in the fluorescent-emitting layer is The triplet excitation energy of the host material is suppressed from transferring to the T1 level of the fluorescent material. Efficiently converting the energy of singlet excitation of fluorescent materials to improve the fluorescence emission efficiency of light-emitting devices The object of the present invention is to provide a phosphorescent layer and a fluorescent layer, and to improve the reliability of the device. In a light-emitting device having layers, the luminous efficiency of both the phosphorescent light-emitting layer and the fluorescent light-emitting layer can be improved. The purpose of this document is to:

[0015] 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.

[0016] 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]

[0017] One embodiment of the present invention includes a first light-emitting layer and a second light-emitting layer between a pair of electrodes. The present invention relates to a semiconductor device comprising a first material and a second material, the first material being capable of converting triplet excitation energy into light emission. the first material has a function of converting singlet excitation energy into light emission, and has 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; and the second light-emitting layer has one of the alkylsilyl groups, and light emission is obtained from the second material, and the second light-emitting layer is The third material and the fourth material have a function of converting triplet excitation energy into luminescence. The longest wavelength is observed in the emission spectrum of the third material and the absorption spectrum of the fourth material. It is a light-emitting device in which the absorption bands of two semiconductors overlap.

[0018] Another embodiment of the present invention is a light-emitting element having a first light-emitting layer and a second light-emitting layer between a pair of electrodes, The first light-emitting layer has a first material and a second material, and the first material has a triplet excitation energy The first material has a function of converting singlet excitation energy into light emission, and the second material has a function of converting singlet excitation energy into light emission. and has a luminophore and five or more protecting groups, the luminophore being a condensed aromatic ring or a condensed complex ring. The five or more protecting groups are each independently an alkyl group having 1 to 10 carbon atoms. a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms; The second material has any one of the following trialkylsilyl groups, and light emission is obtained from the second material. The light-emitting layer includes a sixth material, a seventh material, and a fourth material, and the fourth material has triplet excitation energy. The sixth and seventh materials have the function of converting energy into light emission, and the sixth and seventh materials form an exciplex to emit light. The longest wavelength absorption band overlaps in the emission spectrum of the catalytic complex and the absorption spectrum of the fourth material. It is a light-emitting device.

[0019] 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 A trialkylsilyl group having 3 to 12 carbon atoms is preferable.

[0020] Another embodiment of the present invention is a light-emitting element having a first light-emitting layer and a second light-emitting layer between a pair of electrodes, The first light-emitting layer has a first material and a second material, and the first material has a triplet excitation energy The first material has a function of converting singlet excitation energy into light emission, and the second material has a function of converting singlet excitation energy into light emission. and having a luminophore and at least four protecting groups, the luminophore being a fused aromatic ring or The four protecting groups are not directly bonded to the fused aromatic ring or the fused aromatic ring. The four protecting groups are each independently an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted alkyl group, Unsubstituted cycloalkyl groups having 3 to 10 carbon atoms, trialkyl groups having 3 to 12 carbon atoms The second light-emitting layer has one of a silyl group and a phenylsilyl group, and light emission is obtained from the second material, and the second light-emitting layer has a third The fourth material has a function of converting triplet excitation energy into light emission. The longest wavelength absorption spectrum in the emission spectrum of the third material and the absorption spectrum of the fourth material is It is a light-emitting device with overlapping bands.

[0021] Another embodiment of the present invention is a light-emitting element having a first light-emitting layer and a second light-emitting layer between a pair of electrodes, The first light-emitting layer has a first material and a second material, and the first material has a triplet excitation energy The first material has a function of converting singlet excitation energy into light emission, and the second material has a function of converting singlet excitation energy into light emission. and having a luminophore and at least four protecting groups, the luminophore being a fused aromatic ring or The four protecting groups are not directly bonded to the fused aromatic ring or the fused aromatic ring. The four protecting groups are each independently an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted alkyl group, Unsubstituted cycloalkyl groups having 3 to 10 carbon atoms, trialkyl groups having 3 to 12 carbon atoms The second light-emitting layer has one of a silyl group and a phenylsilyl group, and light emission is obtained from the second material, and the second light-emitting layer has a third The fourth material has a function of converting triplet excitation energy into light emission. The longest wavelength absorption spectrum in the emission spectrum of the third material and the absorption spectrum of the fourth material is It is a light-emitting device with overlapping bands.

[0022] Another embodiment of the present invention is a light-emitting element having a first light-emitting layer and a second light-emitting layer between a pair of electrodes, The first light-emitting layer has a first material and a second material, and the first material has a triplet excitation energy The first material has a function of converting singlet excitation energy into light emission, and the second material has a function of converting singlet excitation energy into light emission. the second material has a luminophore and two or more diarylamino groups, the luminophore being fused Aromatic ring or condensed heteroaromatic ring, the condensed aromatic ring or condensed heteroaromatic ring having two or more diaryl rings. and each of the aryl groups in the two or more diarylamino groups is independently , and at least one protecting group, the protecting group being an alkyl group having 3 to 10 carbon atoms, 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. the second light-emitting layer has a third material and a fourth material, and the fourth material The function of the third material is to convert triplet excitation energy into light emission, and the emission spectrum of the third material and the This is a light-emitting device in which the longest wavelength absorption bands in the absorption spectra of materials 1 and 2 overlap.

[0023] Another embodiment of the present invention is a light-emitting element having a first light-emitting layer and a second light-emitting layer between a pair of electrodes, The first light-emitting layer has a first material and a second material, and the first material has a triplet excitation energy The first material has a function of converting singlet excitation energy into light emission, and the second material has a function of converting singlet excitation energy into light emission. and has a luminophore and two or more diarylamino groups, the luminophore being a condensed aromatic ring or is a condensed heteroaromatic ring, and the condensed aromatic ring or the condensed heteroaromatic ring is a condensed heteroaromatic ring having two or more diarylamino groups. group, and each of the aryl groups in the two or more diarylamino groups is independently at least The protecting groups are an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted alkyl group, Substituted cycloalkyl groups with 3 to 10 carbon atoms, trialkyl groups with 3 to 12 carbon atoms The first material has a T1 level higher than the S1 level of the second material. the second light-emitting layer has a third material and a fourth material, the fourth material being triplet excited. It has the function of converting photoelectron energy into light emission, and the emission spectrum of the third material and the fourth material This is a light-emitting device in which the longest wavelength absorption bands overlap in the absorption spectrum.

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

[0025] Another embodiment of the present invention is a light-emitting element having a first light-emitting layer and a second light-emitting layer between a pair of electrodes, The first light-emitting layer has a first material and a second material, and the first material has a triplet excitation energy The first material has a function of converting singlet excitation energy into light emission, and the second material has a function of converting singlet excitation energy into light emission. The photoresist has a function of reacting with a luminophore and a plurality of protecting groups, and the luminophore is a condensed aromatic ring or a condensed heteroaromatic ring. The protecting groups are each independently an alkyl group having 3 to 10 carbon atoms, or unsubstituted cycloalkyl group having 3 to 10 carbon atoms; At least one of the atoms constituting the multiple protecting groups is an alkylsilyl group. , located directly on one side of the condensed aromatic ring or condensed heteroaromatic ring and having a plurality of protecting groups. At least one of the atoms constituting the fused aromatic ring or the fused heteroaromatic ring is located directly above the other face of the fused aromatic ring or the fused heteroaromatic ring. The second light-emitting layer has a third material and a fourth material, and the third light-emitting layer has a fourth material and a fourth material. The fourth material has the function of converting triplet excitation energy into light emission, and the third material has an emission spectrum A light-emitting device in which the longest wavelength absorption bands in the absorption spectra of the first and second materials overlap. It is.

[0026] Another embodiment of the present invention is a light-emitting element having a first light-emitting layer and a second light-emitting layer between a pair of electrodes, The first light-emitting layer has a first material and a second material, and the first material has a triplet excitation energy The first material has a function of converting singlet excitation energy into light emission, and the second material has a function of converting singlet excitation energy into light emission. and has a luminophore and two or more diphenylamino groups, the luminophore being a condensed aromatic ring or is a condensed heteroaromatic ring, and the condensed aromatic ring or the condensed heteroaromatic ring is a condensed heteroaromatic ring having two or more diphenylamino groups. The phenyl groups in the two or more diphenylamino groups each independently have a 3-position and and 5-positions have protecting groups, each of which is independently an alkyl group having 3 to 10 carbon atoms. , a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, The second material has one of the following trialkylsilyl groups, and the second material has a second emission: The layer has a third material and a fourth material, the fourth material converting triplet excitation energy into luminescence. The third material has a function of absorbing the fourth material at a wavelength of 100 nm to 150 nm. It is a light-emitting device that overlaps with the long-wavelength absorption bands of ZnO and ZnO.

[0027] In the above structure, the alkyl group is preferably a branched chain alkyl group.

[0028] In the above structure, it is preferable that the branched alkyl group has a quaternary carbon.

[0029] 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.

[0030] In the above structure, the light-emitting layer further includes a fifth material, and the first material and the fifth material It is preferred that the compound form an exciplex.

[0031] In the above configuration, the emission spectrum of the first exciplex is in the longest wavelength absorption band of the second material. It is preferable that they overlap.

[0032] In the above configuration, the third material is composed of a sixth material and a seventh material, Preferably, the seventh material forms a second exciplex and the third material is the second exciplex.

[0033] In the above structure, the first material is a first phosphorescent material, and the fourth material is a second phosphorescent material. A phosphorescent material is preferred.

[0034] In the above-mentioned configuration, the first material is a compound exhibiting thermally activated delayed fluorescence, and the fourth material is a compound exhibiting thermally activated delayed fluorescence. Preferably, the material is a phosphorescent material.

[0035] In the above configuration, the energy value of the peak of the emission spectrum of the third material and the energy value of the peak of the emission spectrum of the fourth material are The difference between the energy value of the longest wavelength absorption band peak in the absorption spectrum of the material is 0 It is preferable that it is 0.2 eV or less.

[0036] In the above configuration, the color of light emitted from the first light-emitting layer and the color of light emitted from the second light-emitting layer are different. It is preferable that the emission colors of the first and second light-emitting layers are different from each other, and the peak wavelength of the emission spectrum obtained from the first light-emitting layer is It is more preferable that the wavelength of the light emitting layer is shorter than the peak wavelength of the emission spectrum obtained from the second light emitting layer. I wish.

[0037] 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

[0038] 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. It is possible to provide a display device.

[0039] 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. From this, it is possible to extract other effects. [Brief description of the drawings]

[0040] [Figure 1] 1A and 1B are schematic cross-sectional views of a light-emitting device according to one embodiment of the present invention. [Diagram 2] FIG. 2A 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. 2B is a diagram illustrating the correlation between energy levels. [Diagram 3] 3A and 3B are schematic diagrams of conventional guest materials and guest materials used in a light-emitting device according to one embodiment of the present invention. [Figure 4] 4A and 4B are structural formulas and ball-and-stick diagrams of guest materials used in light-emitting devices according to embodiments 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 Figs. 5B to 5D are diagrams illustrating the correlation between energy levels of the light-emitting layer of a light-emitting device according to one embodiment of the present invention. [Figure 6] Fig. 6A is a schematic cross-sectional view of a light-emitting layer of a light-emitting device according to one embodiment of the present invention, Fig. 6B and Fig. 6C are diagrams illustrating the correlation between the energy levels of the light-emitting layer of a light-emitting device according to one embodiment of the present invention. [Figure 7] Fig. 7A 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. 7B and Fig. 7C are diagrams illustrating the correlation between the energy levels of the light-emitting layer of a light-emitting device according to one embodiment of the present invention. [Figure 8] Fig. 8A is a schematic cross-sectional view of a light-emitting layer of a light-emitting device according to one embodiment of the present invention, Fig. 8B and Fig. 8C are diagrams illustrating the correlation between the energy levels of the light-emitting layer of a light-emitting device according to one embodiment of the present invention. [Figure 9] Fig. 9A is a schematic cross-sectional view of a light-emitting layer of a light-emitting device according to one embodiment of the present invention, Fig. 9B and Fig. 9C are diagrams illustrating the correlation between the energy levels of the light-emitting layer of a light-emitting device according to one embodiment of the present invention. [Figure 10] Fig. 10A 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. 10B and Fig. 10C are diagrams illustrating the correlation between the energy levels of the light-emitting layer of a light-emitting device according to one embodiment of the present invention. [Figure 11] Fig. 11A 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. 11B is a diagram illustrating the correlation between energy levels of the light-emitting layer of a light-emitting device according to one embodiment of the present invention. [Figure 12] FIG. 12 is a schematic cross-sectional view of a light-emitting device according to one embodiment of the present invention. [Figure 13] 13A is a top view illustrating a display device of one embodiment of the present invention, and FIG 13B is a schematic cross-sectional view illustrating a display device of one embodiment of the present invention. [Figure 14] 14A and 14B are schematic cross-sectional views illustrating a display device of one embodiment of the present invention. [Figure 15] 15A and 15B are cross-sectional schematic diagrams illustrating a display device of one embodiment of the present invention. [Figure 16] 16A to 16D are perspective views illustrating a display module of one embodiment of the present invention. [Figure 17] 17A to 17C are diagrams illustrating electronic devices of one embodiment of the present invention. [Figure 18] 18A and 18B are perspective views illustrating a display device of one embodiment of the present invention. [Figure 19] FIG. 19 illustrates a lighting device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0041] 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 not limited to the embodiments described below. The terms of the present disclosure are not to be construed as being limited to the content.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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:

[0046] 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.

[0047] 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.

[0048] 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.

[0049] In the present specification and the like, the light-emitting layer is a layer containing one or more fluorescent materials or phosphorescent materials. The fluorescent layer is a layer from which fluorescent light is obtained, and the phosphorescent layer is a layer from which phosphorescent light is obtained. When a current is passed through the light-emitting device, the light-emitting device emits light. From the light emitting layer, light emission originating from the fluorescent material or phosphorescent material contained therein can be obtained.

[0050] (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.

[0051] <Example of light-emitting device configuration> First, a structure of a light-emitting device of one embodiment of the present invention will be described below with reference to FIG.

[0052] 1A and 1B are diagrams illustrating a light-emitting device 150 and a light-emitting device 152 according to an embodiment of the present invention. FIG.

[0053] The light emitting device 150 and the light emitting device 152 each include a pair of electrodes (electrodes 101 and The light-emitting device has an EL layer 100 or an EL layer 200 provided between the pair of electrodes. The EL layer 100 and the EL layer 200 include at least the light-emitting layer 130a and the light-emitting layer 130b. has.

[0054] In addition to the light-emitting layer 130a and the light-emitting layer 130b, the EL layer 100 shown in FIG. Functional layers such as an injection layer 111, a hole transport layer 112, an electron transport layer 118, and an electron injection layer 119. 1B further includes a separation layer 120. 00 is a configuration in which a separation layer 120 is added to an EL layer 100 .

[0055] In this embodiment, of the pair of electrodes, electrode 101 is an anode, and electrode 1 The light emitting device 150 and the light emitting device 152 are configured as follows: In other words, the electrode 101 is a cathode, the electrode 102 is an anode, and the electrodes The layers between the electrodes may be stacked in the reverse order. a hole transport layer 112; an emissive layer 130a; an emissive layer 130b; an electron transport layer 118; The electron-injecting layer 119 may be stacked in this order.

[0056] 1A and 1B also show that the hole transport layer 112 and the light emitting layer 130a are connected to the electron transport layer 118. Although the light-emitting layers 130b are shown adjacent to each other, the light-emitting device 150 and the light-emitting The configuration of the light emitting device 152 is not limited to this. Device 152 includes hole transport layer 112 and light emitting layer 130b, electron transport layer 118 and light emitting layer 13 A configuration in which 0a are adjacent to each other is also possible.

[0057] The configurations of the EL layer 100 and the EL layer 200 are not limited to those shown in FIGS. 1A and 1B. The hole injection layer 111, the hole transport layer 112, the electron transport layer 118, and the electron injection layer 119 Alternatively, the EL layer 100 and the The EL layer 200 has a function of reducing the hole or electron injection barrier and improving the hole or electron transport property. Inhibits the transport of holes or electrons, or suppresses the quenching phenomenon caused by the electrode. The functional layers may each have a function of being able to It may be a single layer or a laminate of multiple layers.

[0058] In this embodiment, the light-emitting layer 130a is a fluorescent light-emitting layer containing a fluorescent material, and the light-emitting layer 13 0b is described as a phosphorescent light-emitting layer containing a phosphorescent material. Both fluorescent and phosphorescent emissions can be obtained from the chair.

[0059] <Light Emitting Mechanism of the Light Emitting Layer 130a> Next, the light emitting mechanism of the light emitting layer 130a, which is a fluorescent light emitting layer, will be described below.

[0060] In the light-emitting device 150 and the light-emitting device 152 according to an embodiment of the present invention, a pair of electrodes By applying a voltage between the electrodes (electrode 101 and electrode 102), electrons flow from the cathode and Holes are injected from the EL layer 100 or EL layer 200, respectively, and a current flows. Among the excitons generated by the recombination of carriers (electrons and holes), there are singlet excitons and The ratio of triplet excitons (hereafter referred to as exciton generation probability) is 1:3 due to statistical probability. That is, the rate at which singlet excitons are generated is 25%, and the rate at which triplet excitons are generated is 75%. %, the contribution of triplet excitons to light emission can improve the luminous efficiency of light-emitting devices. Therefore, the light-emitting layer 130a is required to have triplet excitation energy. It is preferable to use a material having a function of converting light into light.

[0061] Phosphorescent materials are examples of materials that have the function of converting triplet excitation energy into light emission. In this specification, the term "phosphorescent material" refers to a material that emits light in a temperature range from a low temperature (e.g., 77 K) to room temperature. The material exhibits phosphorescence and fluorescence in any of the following temperature ranges (i.e., 77K or higher and 313K or lower). The phosphorescent material is a compound that does not exhibit the spin-orbit coupling. It is preferable that the metal oxide has a transition metal element, and more preferably, a platinum group element (ruthenium ( Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (I It is preferable that the metal oxide has iridium (Ir) or platinum (Pt), and among them, iridium is preferable. With r, the transition probability for the direct transition between the singlet ground state and the triplet excited state is can be increased.

[0062] In addition, TADF materials have the function of converting triplet excitation energy into light emission. In addition, TADF materials are materials in which the difference between the S1 and T1 levels is small and the inverse intersystem By crossing, energy is converted from triplet excitation energy to singlet excitation energy. Therefore, triplet excitation energy can be converted to 100 times the normal state by a small amount of thermal energy. It is possible to upconvert to singlet excited energy (reverse intersystem crossing) by In addition, it is possible to generate excited states by using two types of substances called exciplexes. The xiplex, exciplex or exciplex is the S1 level. The difference with the T1 level is extremely small, and triplet excitation energy is converted to singlet excitation energy. It functions as a TADF material that can

[0063] As an index of the T1 level, the phosphorescence spectrum observed at low temperatures (e.g., 10 K) is used. As for TADF materials, those that emit light at the short wavelength side of the spectrum at room temperature or low temperatures are Draw a tangent at the tail of the line, and define the energy of the wavelength of the extrapolated line as the S1 level. A tangent line was drawn at the base of the short wavelength side of the curve, and the energy of the wavelength of the extrapolated line was set as the T1 level. In this case, it is preferable that the difference between S1 and T1 is 0.2 eV or less.

[0064] In addition, perovskite is a material that has the function of converting triplet excitation energy into light emission. Nanostructures of transition metal compounds having perovskite structures are particularly well known. Nanostructures of bismuth oxide are preferred. Examples of such nanostructures include nanoparticles and nanorods. is preferred.

[0065] FIG. 2A is a schematic cross-sectional view showing a light-emitting layer 130a of a light-emitting device according to one embodiment of the present invention. In one embodiment of the present invention, the light-emitting layer 130a includes the compound 131 and the compound 132. Compound 131 has the function of converting triplet excitation energy into luminescence, and compound 132 has the function of converting singlet excitation energy into luminescence. It has the function of converting energy into light. Fluorescent materials are highly stable, so they are highly reliable. In order to obtain a light-emitting device with good light emission properties, it is preferable to use a fluorescent material as compound 132. In addition, compound 131 has the function of converting triplet excitation energy into luminescence, To obtain efficient light-emitting devices, it is desirable for carrier recombination to occur in compound 131. Therefore, the singlet excited energies of excitons generated by carrier recombination in compound 131 are Both the triplet excited energy and the triplet excited energy are finally transferred to the singlet excited state of compound 132. It is preferable that the energy is transferred to the compound 132, and the compound 132 emits light. Compound 131 is the energy donor and compound 132 is the energy acceptor. In FIG. 2A and FIG. 2B, the light-emitting layer 130a contains the compound 131 as a host material and the compound 13 2A and 2B, the fluorescent layer has a host The material functions as an energy donor, and the guest material functions as an energy acceptor. In addition, the light-emitting layer 130a can emit light derived from the compound 132, which is a guest material. do.

[0066] <Configuration Example 1 of Light Emitting Layer 130a> FIG. 2B shows an example of the correlation of energy levels in an emitting layer in a light emitting device according to one embodiment of the present invention. In this configuration example, a TADF material is used for compound 131.

[0067] In addition, the energy levels of the compounds 131 and 132 in the light-emitting layer 130a are The correlation is shown in Figure 2B. The vertical axis of Figure 2B represents energy (arbitrary unit). The notations and symbols in FIG. 2B are as follows: ·Host(131): Compound 131 ·Guest(132): Compound 132 T C1 :T1 level of compound 131 ·S C1: S1 level of compound 131 ·S G : S1 level of compound 132 T G :T1 level of compound 132

[0068] Here, we focus on the triplet excitation energy of compound 131 generated by current excitation. Compound 131 has TADF properties. Therefore, compound 131 can increase the triplet excitation energy. It has the function of converting it into singlet excitation energy by upconversion (Figure 2B). The singlet excitation energy of compound 131 is rapidly transferred to compound 132. (Fig. 2B Route A2). At this time, S C1 ≧S G It is preferable that Specifically, a tangent line is drawn at the short wavelength side of the fluorescence spectrum of compound 131, and the The energy of the wavelength of the extrapolated line is S C1 The wavelength of the absorption edge of the absorption spectrum of compound 132 is The energy of S G When this is done, S C1 ≧S G It is preferable that the compound 13 is Since 1 is a material with TADF properties, S C1 and T C1 is very small. Therefore, S C 1 ≧ S T1 ≧S G It could be.

[0069] The triplet excitation energy generated in compound 131 is converted to the acetylated ketone via the above-mentioned routes A1 and A2. The energy is transferred to the S1 level of the photoresist material, compound 132, causing compound 132 to emit light. In route A2, the luminous efficiency of the fluorescent light-emitting device can be improved. Compound 131 acts as an energy donor, and compound 132 acts as an energy acceptor. .

[0070] Here, in the light-emitting layer 130a, the compound 131 and the compound 132 are mixed. Therefore, the triplet excitation energy of compound 131 competes with the above routes A1 and A2. The process of conversion to triplet excitation energy of compound 132 (Figure 2B Route A3) occurs. Since compound 132 is a fluorescent material, the triplet excitation energy of compound 132 is emitted. In other words, when the energy transfer of route A3 occurs, the light emission of the light-emitting device In reality, the efficiency of T C1 From T G Energy transfer to (route A3) is not directly, but the T of compound 132 G Once energy transfers to a higher triplet excited state 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 rest of this specification, the undesirable thermal deactivation process, i.e., T G The inactivation process to , are all similar.

[0071] Here, the mechanism of intermolecular energy transfer is the Förster mechanism (dipole-dipole interaction). The Dexter mechanism (electron exchange interaction) is known. Energy acceptor Since compound 132, which is a fluorescent material, the energy transfer of route A3 is Dexter Generally, the Dexter mechanism is dominated by the energy donor compound 131. The distance between the ion beam and the energy acceptor, compound 132, is significantly less than 1 nm. Therefore, in order to suppress route A3, the distance between the host material and the guest material, i.e., the energy It is important to keep the distance between the donor and the energy acceptor large.

[0072] 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.

[0073] T in Figure 2B 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.

[0074] 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 above-mentioned decrease in luminous efficiency and reliability can be reduced. In addition, when a phosphorescent light-emitting layer and a fluorescent light-emitting layer are combined, The inventors have also found that this can suppress the decrease in the luminous efficiency of the phosphorescent-emitting layer that occurs in the above-mentioned process.

[0075] <Concept of fluorescent materials having protecting groups> FIG. 3A shows a typical fluorescent material that does not have a protecting group as a guest material. FIG. 3B shows a schematic diagram of the case where the fluorine-containing compound is dispersed in a light-emitting material 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. 3A, guest material 301 has luminophores 310. On the other hand, in FIG. 3B, the guest material 30 2 has a luminophore 310 and a protecting group 320. Also, in FIG. 3A and FIG. 3B, 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. energy transfer via the Förster mechanism (Route A4 in Figures 3A and 3B) Both the Dexter mechanism and route A5 in Fig. 3A and Fig. 3B 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.

[0076] On the other hand, in FIG. 3B, 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 A5) can be suppressed.

[0077] 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, when the distance between the host material 330 and the guest material 302 is 1 nm or less, the Dexter mechanism prevails. In the range of 1 nm to 10 nm, the Förster mechanism is dominant. If the distance between the material 330 and the guest material 302 is 10 nm or more, energy transfer is unlikely to occur. Here, the distance between the host material 330 and the guest material 302 is This can be read as the distance.

[0078] 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.

[0079] 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.

[0080] On the other hand, in the light-emitting device according to one embodiment of the present invention, a guest material having a protecting group on a light-emitting group is included in the light-emitting layer. Therefore, the energy transfer by the Dexter mechanism is suppressed while the Förster mechanism is used. Since the energy transfer by the - mechanism can be efficiently utilized, This allows the concentration of the guest material, which is the catalyst, to be increased. As a result, the Dexter mechanism It suppresses energy transfer while increasing the rate of energy transfer via the Förster mechanism. This makes it possible to realize phenomena that are essentially contradictory. Increasing the transfer rate shortens the excited lifetime of the energy acceptor in the light-emitting layer. Therefore, the reliability of the light-emitting device can be improved. The preferred range is 2 wt% to 30 wt%, and more preferably 5 wt% to 20 wt%. % or less, and more preferably 5 wt % to 15 wt %. This increases the rate of energy transfer via the Förster mechanism, resulting in higher luminous efficiency. Furthermore, it is possible to obtain a light-emitting device with high light emission efficiency by converting 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. In addition, the above concentration is determined based on the light-emitting layer, where the material that mainly emits light is the guest material. The concentration is when a material other than the target material is used as the host material.

[0081] 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 element. It is possible.

[0082] 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 considered as a group of atoms (skeleton) containing aromatic rings on which the dipole vector exists. When one fluorescent material has a plurality of condensed aromatic rings or condensed heteroaromatic rings, the plurality of condensed aromatic rings or heteroaromatic rings may be The aromatic ring or the condensed heteroaromatic ring is selected from the group consisting of a skeleton having the lowest S1 level and a structure having the lowest S1 level. In addition, the longest one of the plurality of condensed aromatic rings or condensed heteroaromatic rings may be considered as a group. The skeleton having an absorption edge at a wavelength may be considered as the luminophore of the fluorescent material. The emission spectrum of the condensed aromatic ring or condensed heteroaromatic ring is used to determine the emission characteristics of the fluorescent material. In some cases it is possible to predict light bands.

[0083] 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.

[0084] In addition, the substituents used as protecting groups have a higher T1 level than the luminophore and the host material. It is necessary to have a triplet excited energy level. Therefore, it is preferable to use a saturated hydrocarbon group. This is because the triplet excitation energy level of a substituent that does not have a π bond is high. However, a substituent that does not have a π bond has a low function of transporting carriers (electrons or holes). Therefore, the saturated hydrocarbon group has little effect on the excited state or carrier transport properties of the host material. The distance between the luminophore and the host material can be increased without providing a π bond. In an organic compound having both a substituent and a substituent having a π-conjugated system, The frontier orbital {HOMO(Highest Occupied Mol luminal orbital (also called the highest occupied molecular orbital) and LUMO (Lowest Occupied Molecular Orbital) Unoccupied Molecular Orbital (Lowest Unoccupied Orbital) In many cases, the luminophores have frontier orbitals. As described above, energy transfer by the Dexter mechanism requires an energy donor and an energy accessor. The overlap of the HOMO and LUMO of the scepter is important. By using a basic group as a protecting group, the frontier of host materials that are energy donors can be expanded. By increasing the distance between the orbital and the frontier orbital of the guest material, which is the energy acceptor, This makes it possible to suppress energy transfer via the Dexter mechanism.

[0085] Specific examples of the protecting group include alkyl groups having 1 to 10 carbon atoms. Since the group is required to increase the distance between the luminophore and the host material, bulky substituents are preferred. Therefore, an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted alkyl group having 3 to 10 carbon atoms, The following cycloalkyl groups and trialkylsilyl groups having 3 to 12 carbon atoms are preferably used: In particular, the alkyl group is preferably a bulky branched chain alkyl group. The substituent is particularly preferably one having a quaternary carbon since it becomes a bulky substituent.

[0086] 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 3B shows the state in which the luminophore and the protecting group are directly bonded. 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.

[0087] 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

[0088] <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.

[0089] [ka]

[0090] A ball-and-stick model representation of the above 2tBu-mmtBuDPhA2Anth is shown in FIG. 4B. In addition, in Figure 4B, 2tBu-mmtBuDPhA2Anth is connected in the direction of the arrow in Figure 4A (antrail). The shaded area in Figure 4B shows the light-emitting area. The anthracene ring plane is a ring structure, and the tBu group is a protecting group. For example, the atom indicated by the arrow (a) in FIG. 4B is in the The atom indicated by the arrow (b) is a carbon atom of the tBu group that overlaps with the shaded portion. The hydrogen atoms of the overlapping tBu groups, i.e. 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.

[0091] In addition, the energy transfer by the Dexter mechanism is, for example, If the transition is between the OMO and LUMO, the HOMO of the host and guest materials overlap. The overlap of the LUMOs of the host and guest materials is important. When UMOs overlap, the Dexter mechanism is significantly activated. Therefore, the Dexter mechanism is suppressed. In order to achieve this, it is important to suppress the overlap of the HOMO and LUMO of both materials. In particular, it is important to keep the distance between the skeleton involved in the excited state and the host material. In fluorescent materials, both the HOMO and LUMO are often possessed by a luminophore. For example, The HOMO and LUMO of the guest material are above and below the plane of the luminophore (2tBu-mmtBuD In PhA2Anth, when the anthracene ring is extended above and below the anthracene ring, the emission It is important in the molecular structure that the faces of the antagonism are covered above and below with protecting groups. The upper and lower parts of the helical ring are defined as the upper and lower parts of the anthracene ring as viewed from the arrow in FIG. 4A. It represents the below.

[0092] 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. 4B, -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. 4) is a fused aromatic ring. Located directly above one face of an aromatic ring or a condensed heteroaromatic ring (anthracene ring in Figure 4) and at least one of the atoms constituting the plurality of protecting groups is the condensed aromatic ring or condensed complex. By adopting this structure, the guest material is located directly above the other face of the aromatic ring. Even when dispersed in a material, the distance between the luminophore and the host material can be increased, It is possible to suppress the energy transfer by the star mechanism. Preferably, a protecting group such as a tBu group is placed over the luminophore.

[0093] <Configuration Example 2 of Light-Emitting Layer 130a> FIG. 5C illustrates a light-emitting device 150 and a light-emitting layer 130 of a light-emitting device 152 according to an embodiment of the present invention. The light-emitting layer 130a shown in FIG. 131, compound 132, and further compound 133. Preferably, the compound 132 is a fluorescent material. Compound 133 is a combination that forms an exciplex.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] For example, when compound 131 has a hole transporting property and compound 133 has an electron transporting property, As shown in the energy band diagram in FIG. 5B, the HOMO level of compound 131 is The HOMO level of compound 131 is preferably higher than the HOMO level of compound 133. 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 131 and Compound 133 are preferred because they are easily injected.

[0098] In FIG. 5B, 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.

[0099] In addition, when Compound 131 and Compound 133 form an exciplex, HO of Compound 131 A hole is injected into the LUMO of compound 133, and an electron is injected into the LUMO of compound 133. The excitation energy of the compound 133 is the energy between the LUMO level of the compound 133 and the HOMO level of the compound 131. Energy difference (ΔE E ) and the offset between the LUMO and HOMO levels of compound 131 is Energy difference (ΔE C1 ) and the energies of the LUMO and HOMO levels of compound 133 Difference (ΔE C3 ) is smaller than the exciplex of compound 131 and compound 133. By forming the , it is possible to form an excited state with lower excitation energy. In addition, because it has a lower excitation energy, the exciplex forms a stable excited state. This can be done.

[0100] In addition, the compounds 131, 132, and 133 in the light-emitting layer 130a The correlation of the energy levels is shown in FIG. 5C. The notations and symbols in FIG. 5C 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 T G :T1 level of compound 132 ·S E : S1 level of the exciplex T E :T1 level of the exciplex

[0101] In the light-emitting device of one embodiment of the present invention, the compound 131 contained in the light-emitting layer 130a The S1 level of the exciplex (S E ) and the T1 level of the exciplex (T E ) are adjacent energy levels (see route A6 in Figure 5C).

[0102] 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 a lower excitation energy. The driving voltage of the light-emitting device according to one embodiment can be reduced.

[0103] 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. 5C Route A8). At this time, S E ≧S G is In route A8, 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 at the absorption edge of the absorption spectrum of G When this is done, S E ≧S G To be is preferred.

[0104] 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 shortest emission peak wavelengths in the phosphorescence spectra of compounds 131 and 133 are It is preferable that the fluorescence of the exciplex is equal to or smaller than the maximum emission peak wavelength. Draw a tangent line at the short wavelength side of the spectrum, and let the energy at the wavelength of the extrapolated line be S. E and The tangents at the short wavelength tails of the phosphorescence spectra of Compound 131 and Compound 133 are Then, the energy of the wavelength of the extrapolated line is calculated as T C1 and T C3 When , S E -T C1 ≦0.2 eV and S E -T C3 It is preferred that it is ≦0.2 eV.

[0105] The triplet excitation energy generated in the light-emitting layer 130a is converted into the S1 level of the exciplex by the above-mentioned route A6. The guest material is then transported to the S1 level via energy transfer (route A8). Therefore, the combination of materials that form an exciplex in the light-emitting layer 130a can be used. By using such a material, the luminous efficiency of the fluorescent light-emitting device can be increased.

[0106] 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 A9 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.

[0107] The above-mentioned processes of routes A6 to A8 are referred to as ExSET (Exci plex-Singlet Energy Transfer) or ExEF (Exc It is sometimes called iplex-Enhanced Fluorescence. In other words, the light-emitting layer 130a is a layer in which excitation energy is transferred from an exciplex to a fluorescent material. .

[0108] <Configuration Example 3 of Light-Emitting Layer 130a> In this configuration example, the compound 133 of the light-emitting device using the above-mentioned ExEF is a phosphorescent material. In other words, one of the compounds forming the exciplex has a phosphorescent The case where the material is used will be described.

[0109] 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. To form an exciplex that can transition from the nucleon to the singlet ground state (i.e., can exhibit phosphorescence), In this case, unlike ordinary exciplexes, the triplet excited energy of the exciplex can be generated. Energy level (T E ) is the energy donor level, so T E A compound in which the compound is a light-emitting material The singlet excited energy level of 132 (S G ) or more. The emission spectrum of the exciplex using a compound with a heavy atom in one compound is at the short wavelength tail. Draw a tangent line at the point, and let the energy of the wavelength of the extrapolated line be T E The absorption spectrum of compound 132 was Let the energy of the wavelength at the absorption edge of the G When this is done, T E ≧S G It is preferable that .

[0110] 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 ) to the singlet excited energy of compound 132. Energy Level (S G) energy can be transferred to the S1 level (S E ) and T1 level (T E ) are adjacent energy levels, so the emission spectrum In some cases, it is difficult to clearly distinguish between fluorescence and phosphorescence. It may be possible to distinguish between fluorescence or phosphorescence depending on the

[0111] The phosphorescent material used in the above configuration contains heavy atoms such as Ir, Pt, Os, Ru, and Pd. On the other hand, in this configuration example, the phosphorescent material acts as an energy donor. Therefore, the quantum yield can be either high or low. Allowed transition of energy from the singlet excited energy level of the guest material to the singlet excited energy level of the guest material It would be good if the above-mentioned exciplexes composed of phosphorescent materials and guest molecules composed of phosphorescent materials were used. Energy transfer to the material occurs from the triplet excited energy level of the energy donor to the guest material. The energy transfer to the singlet excited energy level of the energy acceptor is allowed Therefore, the exciplex is formed without going through the process of route A7 in FIG. The triplet excitation energy of the guest material is converted to the S1 level (S G ) In other words, the guest material can be produced only through the steps of Route A6 and Route A8. Triplet and singlet excitation energy can be transferred to the S1 level. In this case, the exciplex acts as the energy donor and compound 132 acts as the energy acceptor. It works like this.

[0112] 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 A9 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.

[0113] <Configuration Example 4 of the Light-Emitting Layer 130a> In this configuration example, the compound 133 of the light-emitting device using the above-mentioned ExEF is a TADF-based compound. The case where a material having the above structure is used will be described with reference to FIG. 5D.

[0114] Since compound 133 is a TADF material, compound 133 that does not form an exciplex is a triplex. A mechanism for converting doublet excitation energy into singlet excitation energy by upconversion (Fig. 5D Route A 10 The singlet excitation energy of compound 133 is: It is possible to rapidly transfer to compound 132. (Figure 5D Route A 11 ). At this time, S C3 ≧S G It is preferable that:

[0115] 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. The triplet excitation energy is transferred to the guest material, compound 132, via route A8. Route A in Fig. 5D 10 and Route A 11 The pathway that transfers to compound 132 There are multiple pathways for triplet excitation energy to be transferred to fluorescent materials. In route A8, the exciplex is an energy donor, and the luminescence efficiency can be further improved. Compound 132 acts as the energy acceptor. 11 To In this case, compound 133 is the energy donor and compound 132 is the energy acceptor. It functions as:

[0116] In this example, the exciplex and compound 133 are energy donors, and compound 132 acts as an energy acceptor.

[0117] <Configuration Example 5 of Light-Emitting Layer 130a> FIG. 6A shows a case where four types of materials are used for the light-emitting layer 130a. The light-emitting layer 130a contains compounds 131, 132, 133, and 134. In one embodiment of the present invention, compound 133 converts triplet excitation energy into luminescence. In this configuration example, the case where the compound 133 is a phosphorescent compound will be described. Compound 132 is a guest material that exhibits fluorescent emission. Compound 131 is also a compound 13 It is an organic compound that forms an exciplex with 4.

[0118] In addition, the compounds 131, 132, and 133 in the light-emitting layer 130a are The energy level correlation of compound 134 is shown in FIG. 6B. are as follows, and other notations and symbols are the same as those shown in FIG. 5C. . ·S C4 : S1 level of compound 134 T C4 :T1 level of compound 134

[0119] In the light-emitting device according to one embodiment of the present invention shown in this configuration example, the light-emitting layer 130a has Compound 131 and compound 134 form an exciplex. The S1 level of the exciplex (S E ) and encouragement T1 level of the complex (T E) are adjacent energy levels (Figure 6B Route A 12 reference).

[0120] 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.

[0121] 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 voltages of the device 150 and the light emitting device 152 can be reduced.

[0122] 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 glycine and glycine are rapidly transferred to compound 133 (Route A 13 ). At this time, T E ≧T C3 In addition, it is preferable that the triplet excitation energy of compound 133 is efficiently converted. The singlet excitation energy of compound 132 can be converted to the 14 ), where ,T, as shown in Figure 6B. E ≧T C3 ≧S G Then, the excitation energy of compound 133 is This is preferred because it efficiently transfers the singlet excitation energy to the guest material, compound 132. Specifically, a tangent line is drawn at the short wavelength side of the phosphorescence spectrum of compound 133, The energy of the wavelength of the extrapolated line is T C3 The absorption edge of the absorption spectrum of compound 132 is The energy of the wavelength is S G When this is done, T C3 ≧S G It is preferable that the formula is: 14 In this study, compound 133 acts as an energy donor and compound 132 acts as an energy acceptor. It functions as such.

[0123] In this case, the combination of Compound 131 and Compound 134 can form an exciplex. Any possible combination is acceptable, but one of them is a compound having hole transport properties and the other is an electron More preferably, the compound has transport properties.

[0124] In addition, the HOMO level of compound 131 is higher than the HOMO level of compound 134. The LUMO level of compound 131 is higher than the LUMO level of compound 134. The HOMO level of compound 134 is higher than that of compound 131, and the L When the UMO level is higher than the LUMO level of compound 131, it is excited efficiently. This is preferred because it is capable of forming a complex.

[0125] In addition, the correlation between the energy levels of compounds 131 and 134 is not limited to that shown in FIG. 6B. That is, the singlet excited energy level of compound 131 (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.

[0126] 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.

[0127] In addition, in the light-emitting device according to one embodiment of the present invention, 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.

[0128] 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 15 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. This allows the concentration of the energy donor, Compound 133, to be increased. While suppressing the energy transfer by the mechanism, the rate of energy transfer by the Förster mechanism is increased. This makes it possible to achieve two contradictory phenomena: By increasing the energy transfer rate, the excitation lifetime of the energy acceptor in the emissive layer can be extended. This can improve the reliability of light-emitting devices because their lifetimes are shorter. Energy donor When compound 133 is added to the light-emitting layer, its concentration is 2 wt% relative to the host material. % or more and 50 wt % or less, more preferably 5 wt % or more and 30 wt % or less, and further The preferred range is 5 wt% or more and 20 wt% or less. This increases the energy transfer rate by the photocatalytic mechanism, resulting in a light-emitting device with high luminescence efficiency. You can get the service.

[0129] In addition, Route A shown above 12 and A 13 The process is referred to as ExTET (E xciplex-Triplet Energy Transfer) In other words, the light-emitting layer 130a is a layer in which the excitation energy from the exciplex to the compound 133 is transferred. Therefore, this configuration example is a fluorescent compound having a protecting group in the light-emitting layer that can utilize ExTET. It can be said that the composition is a mixture of functional materials.

[0130] <Configuration Example 6 of Light-Emitting Layer 130a> In this configuration example, a material having TADF properties is added to the compound 134 described in the above-mentioned configuration example 5 of the light-emitting layer. We will explain the case where a fee is used.

[0131] FIG. 6C shows a case where four types of materials are used for the light-emitting layer 130a. The light-emitting layer 130a contains compounds 131, 132, 133, and 134. In one embodiment of the present invention, compound 133 has the function of converting triplet excitation energy into luminescence. Compound 132 is a guest material that exhibits fluorescent emission. is an organic compound that forms an exciplex with compound 134.

[0132] 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. 6C Route A 16 The singlet excited energy of compound 134 is Ghee can be rapidly transferred to compound 132 (Figure 6C, Route A). 17 ).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 wavelength at the absorption edge of the absorption spectrum of 132 is S G When this is done, S C4 ≧S G in It is preferable that there is.

[0133] 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. 12 Route A 14 The triplet excitation energy is transferred to the guest material, compound 132. The route to travel and route A in Figure 6C 16 and Route A 17 Transfer to compound 132 via There are multiple pathways through which triplet excitation energy can be transferred to fluorescent materials. This can further increase the luminous efficiency. 14 In the present study, compound 133 was The energy donor, compound 132, acts as an energy acceptor. A 17 In the formula, compound 134 is the energy donor and compound 132 is the energy acceptor. It functions as a target.

[0134] <Configuration Example 7 of the Light-Emitting Layer 130a> FIG. 7B illustrates a light-emitting layer 130 of light-emitting device 150 and light-emitting device 152 according to an embodiment of the present invention. The light-emitting layer 130a shown in FIG. 131, compound 132, and further compound 133. Compound 132 is a fluorescent material having a protecting group. Compound 133 is a triplet excitation material. In this configuration example, compound 133 is a phosphorescent material. One case will now be described.

[0135] The notations and symbols in FIG. 7B and FIG. 7C described later are as follows. ·Comp(131): Compound 131 ·Comp(133): Compound 133 ·Guest(132): Compound 132 ·S C1 : S1 level of compound 131 T C1 :T1 level of compound 131 T C3 :T1 level of compound 133 T G :T1 level of compound 132 ·S G : S1 level of compound 132

[0136] In the light-emitting device according to one embodiment of the present invention, the compound 131 in the light-emitting layer 130a The recombination of carriers mainly occurs at the nucleus, generating singlet and triplet excitons. Here, compound 133 is a phosphorescent material, so T C3 ≦T C1 The materials for this relationship By selecting this, both the singlet and triplet excitation energies generated in compound 131 can be obtained by converting the 33T C3 (Figure 7B Route A 18 ). In addition, some The rear can be recombined with compound 133.

[0137] The phosphorescent material used in the above configuration contains heavy atoms such as Ir, Pt, Os, Ru, and Pd. On the other hand, as described above, in this configuration example, the phosphorescent material is preferably an energy Since it acts as a donor, the quantum yield can be high or low. 133, the triplet excited energy level of the energy donor is converted to the guest material. (energy acceptor) to the singlet excited energy level is an allowed transition Therefore, the triplet excitation energy of compound 133 is preferably calculated according to route A. 19 past The S1 level (S G ) can be moved to Root A. 19 To Compound 133 acts as an energy donor and compound 132 acts as an energy acceptor. It works. In this case, T C3 ≧S G In this case, the excitation energy of compound 133 is efficiently This is preferable because it transfers to the singlet excited state of the guest material, compound 132. Draw a tangent line at the short wavelength side of the phosphorescence spectrum of compound 133, and extrapolate the wavelength of the line. Energy T C3 The energy of the wavelength of the absorption edge of the absorption spectrum of compound 132 is S G When this is done, T C3 ≧S G It is preferable that:

[0138] 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 20 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.

[0139] <Configuration Example 8 of Light-Emitting Layer 130a> FIG. 7C illustrates a light-emitting device 150 according to one embodiment of the present invention and a light-emitting layer 130a of the light-emitting device. The light-emitting layer 130a shown in FIG. 7A is made of compound 131. In one embodiment of the present invention, the compound Compound 132 is a fluorescent material having a protecting group. Compound 133 is a compound having triplet excited energy. In this configuration example, compound 133 has TADF properties. The case where the compound is used will be described.

[0140] The notations and symbols in FIG. 7C are as follows, and the other notations and symbols are as shown in FIG. 7B. The notation and symbols are the same as those used in ·S C3 : S1 level of compound 133

[0141] In the light-emitting device according to one embodiment of the present invention, the compound 131 in the light-emitting layer 130a The recombination of carriers mainly occurs at the nucleus, generating singlet and triplet excitons. Here, S C3 ≦S C1 And T C3 ≦T C1 By selecting materials that satisfy the above relationship, Both the singlet excitation energy and triplet excitation energy generated in compound 131 were converted to compound 133. S C3 and T C3 (Figure 7C Route A 21 ). In addition, some The carrier can be recombined with compound 133.

[0142] Here, compound 133 is a TADF material, so it can upconvert triplet excitation energy. It has the function of converting it into singlet excitation energy by the reaction (Figure 7C Route A 22 In addition, the singlet excitation energy of compound 133 is rapidly transferred to compound 132. (Fig. 7C Route A 23 ). At this time, S C3 ≧S G It is preferable that Specifically, a tangent line is drawn at the short wavelength side of the fluorescence spectrum of compound 133, and the The energy of the wavelength of the extrapolated line is S C3 The absorption spectrum of compound 132 is shown in Fig. 1. The energy of the length is S G When this is done, S C3 ≧S G It is preferable that the formula is: 21 No To Route A 23 Through this process, the triplet excitation energy in the light-emitting layer 130a is converted into the compound It can be converted to the fluorescent light of 132. Route A 23 In the present study, compound 133 was The energy donor, compound 132, functions as the energy acceptor.

[0143] 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 24 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.

[0144] <Configuration Example 1 of Light Emitting Layer 130b> Next, the light emitting mechanism of the light emitting layer 130b, which is a phosphorescent light emitting layer, will be described below.

[0145] FIG. 8B illustrates a light-emitting device 150 and a light-emitting layer 130 of a light-emitting device 152 according to an embodiment of the present invention. 8A, 8B, and 8C are diagrams showing an example of the correlation of the energy levels in the light-emitting layers 100 and 102 shown in FIG. 130b has at least compound 135 and compound 136. Compound 136 is a triple In one embodiment of the present invention, compound 13 has a function of converting excitation energy into light emission. 6 is preferably a phosphorescent material. In the example, compound 136 is shown as a phosphorescent material.

[0146] The notations and symbols in FIGS. 8B and 8C are as follows. ·Host(135): Compound 135 ·Guest(136): Compound 136 ·S PH1 : S1 level of compound 135 T PH1 :T1 level of compound 135 T PG :T1 level of compound 136 ·S PG : S1 level of compound 136

[0147] In the light-emitting device according to one embodiment of the present invention, the compound 135 in the light-emitting layer 130b The recombination of carriers mainly occurs at the nucleus, generating singlet and triplet excitons. Here, compound 136 is a phosphorescent material, so T PH3 ≦T GP1 The relationship between By selecting the compound, both the singlet and triplet excitation energies generated in compound 135 can be obtained. T of item 136 PG1 It is possible to move to the next level (Route E1 in Fig. 8B and Fig. 8C). Some of the carriers may recombine with compound 136.

[0148] Compound 136 emits light efficiently, so the longest absorption peak in the absorption spectrum of compound 136 is It is preferable that the wavelength absorption band overlaps with the emission spectrum of compound 135. The longest wavelength absorption band in the absorption spectrum is the strongest absorption band in the entire spectrum and is the most closely related to emission. The emission spectrum of compound 135 shows a single absorption band. Fluorescence spectrum, which is the emission from the single excited state, and phosphorescence spectrum, which is the emission from the triplet excited state. Therefore, in order for compound 136 to emit light efficiently, compound 135 is shown. Both the fluorescence and phosphorescence spectra of the compound overlap with the longest wavelength absorption band of compound 136. By having the overlap, the excitation energy of compound 135 is preferably By adopting this structure, the light emitting layer 130b generates The singlet and triplet excitation energies are efficiently converted to the emission of compound 136. can be converted to

[0149] The fluorescence and phosphorescence spectra of compound 135 are sufficient to determine the longest wavelength absorption of compound 136. The energy values ​​of the fluorescence spectrum peaks of compound 135 and the absorption spectrum overlap with each other. The difference between the peak value of the absorption band of the longest wavelength (lowest energy side) of the tor is 0.2 eV or less. It is preferable that the optical density is 0.1 eV or less. More preferably, the optical density is 0.1 eV or less. By adopting this configuration, the light emission efficiency is improved. The emission layer can have a high absorption coefficient. The magnitude relationship of the peak value of the absorption band at the longest wavelength (lowest energy side) of the absorption spectrum is not important. In other words, the energy value of the peak of the fluorescence spectrum is the longest wavelength (lowest wavelength) of the absorption spectrum. It does not matter whether the absorption band peak value is larger or smaller than the peak value of the absorption band on the other energy side.

[0150] In addition, as shown in FIG. 8C, the energy difference between the S1 and T1 levels of compound 135 is It is more preferable to use a small material. By adopting this structure, it is possible to obtain a high luminous efficiency and a high luminous efficiency. The driving voltage of the optical device can be reduced. The energy difference between the S1 level and the T1 level is Examples of small materials include TADF materials and exciplexes.

[0151] <Configuration Example 2 of Light-Emitting Layer 130b> 9B and 9C are diagrams illustrating the light emitting devices 150 and 152 according to an embodiment of the present invention. 9A, 9B, and 9C are examples of the correlation of energy levels in the optical layer 130b. The light-emitting layer 130b shown in FIG. 1 contains at least one compound 135_1, one compound 135_2, and one compound 136. Compound 136 has the function of converting triplet excitation energy into luminescence. In one embodiment, compound 136 is preferably a phosphorescent material. 9B and 9C, this configuration example shows the case where compound 136 is a phosphorescent material. Compound 135_1 and compound 135_2 are a combination that forms an exciplex.

[0152] Compound 135_1, similar to Compound 131 and Compound 133 in FIG. 5A and FIG. 5B, The combination of and compound 135_2 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 an electric field. It is more preferable that the compound has a function of transporting electrons (electron transport property). The compound symbols are different from those in FIG. 5B, but the other structures are the same. Compound 135_1 and Compound The structure of compound 135_2 is the same as that of compound 131 and compound 133 in FIG. 5B. Therefore, a detailed description of FIG. 9B will be omitted.

[0153] In FIG. 9B, Comp(135_1) represents compound 135_1, and Comp (135_2) represents compound 135_2, ΔE PH2 is the LUMO level of compound 135_1. represents the energy difference between the HOMO level and the PH3 is the LUMO level of compound 135_2. represents the energy difference between the HOMO level and the PH1 is the LUMO level of compound 135_1. are notations and symbols that represent the energy difference between the position and the HOMO level of compound 135_2.

[0154] Furthermore, the notations and symbols in FIG. 9C are as follows. ·Host(135_1): Compound 135_1 ·Host(135_2): Compound 135_2 ·Guest(136): Compound 136 ·S PH2 :S1 level of compound 135_1 T PH2 :T1 level of compound 135_1 ·S PH3 :S1 level of compound 135_2 T PH3 :T1 level of compound 135_2 T PG :T1 level of compound 136 ·S PG : S1 level of compound 136 ·S PE : S1 level of the exciplex T PE :T1 level of the exciplex

[0155] Compound 135_1 and compound 135_2 are compounds in which one accepts holes and the other accepts electrons. The two quickly form an exciplex (see route E2 in Figure 9C). When the electron enters the excited state, it quickly interacts with another electron to form an exciplex. Energy level (S PE or TPE ) is a host material (compound 135) that forms an exciplex. _1 and compound 135_2) S1 level (S PH1 and S PH2 ) is lower, so This allows the excited state of compound 135 to be formed with lower excitation energy. This allows the driving voltage of the light emitting device to be reduced.

[0156] And the (S PE ) and (T PE ) and compound 136 (phosphorus The photoelectron beam can be transferred to the T1 level of the photoactive compound to emit light (see routes E3 and E4 in Figure 9C). .

[0157] The above-described process of routes E1 to E4 is referred to as ExTET in this specification. In other words, the light-emitting layer 130b may be configured to convert the excited energy from the exciplex to the compound 136. Therefore, in this configuration example, the light-emitting layer 130b is configured to use ExTET. It is a completion.

[0158] Compound 136 emits light efficiently, so the longest absorption peak in the absorption spectrum of compound 136 is It is preferable that the wavelength absorption band and the emission spectrum of the exciplex overlap. It is known that the T1 and T2 levels are close to each other. At least one of the absorption bands of the longest wavelength of compound 136 overlaps with the absorption band of the longest wavelength of compound 136. As a result, the dual excitation energy of singlet and triplet generated in the light-emitting layer 130b is The photoluminescence of compound 136 can be efficiently converted into the luminescence of compound 136.

[0159] The fluorescence or phosphorescence spectrum of the exciplex is sufficient to determine the absorption spectrum of compound 136. The energy value of the peak in the fluorescence spectrum of the exciplex because it overlaps with the absorption band with the longest wavelength The difference between the peak value of the absorption band at the longest wavelength (lowest energy side) of the absorption spectrum is 0.2e It is preferable that the ion concentration is 0.5 eV or less, and more preferably 0.1 eV or less. As a result, a phosphorescent light-emitting layer with high luminous efficiency can be obtained. The energy value of the peak and the longest wavelength (low energy side) of the absorption spectrum of compound 136 The magnitude relationship of the peak value of the absorption band of the exciplex is not important. The energy value of the peak is the longest wavelength (lowest energy side) of the absorption spectrum of compound 136. It may be larger or smaller than the peak value of the absorption band.

[0160] <Configuration Example 1 of the Light-Emitting Layer 130a and the Light-Emitting Layer 130b> The light-emitting device according to one embodiment of the present invention has both the light-emitting layer 130a and the light-emitting layer 130b described above. FIG. 10B illustrates a light-emitting layer 1 of light-emitting device 150 and light-emitting device 152 according to an embodiment of the present invention. FIG. 10A shows an example of the correlation of energy levels in the light-emitting layers 30a and 130b. The light-emitting layer 130a is made of a compound 131_ The light-emitting layer 130b contains the compound 135_p and the compound 132_f. In one embodiment of the present invention, compound 132_f is a fluorescent compound having a protecting group. Compound 131_f has the function of converting triplet excitation energy into luminescence. In this configuration example, the compound 131_f is a material having TADF properties, and the compound The case where 136_p is a phosphorescent material will be described. The light-emitting layer 130a has the structure shown in the configuration example 1 of the light-emitting layer 130a, and the light-emitting layer 130b has the structure shown in the configuration example 1 of the light-emitting layer 130a. 130b. The energy transfer of route A3 and route E1 is as described above.

[0161] The notations and symbols in FIG. 10B are as follows: ·F-Host(131_f): Compound 131_f ·F-Guest(132_f): Compound 132_f ·P-Host(135_p): Compound 135_p ·P-Guest(136_p): Compound 136_p ·S FH :S1 level of compound 131_f T FH :T1 level of compound 131_f ·S FG :S1 level of compound 132_f T FG :T1 level of compound 132_f ·S PH : S1 level of compound 135_p T PH :T1 level of compound 135_p T PG :T1 level of compound 136_p

[0162] As shown in FIG. 10A, the light-emitting layer 130a and the light-emitting layer 130b are adjacent to each other. When the phosphorescent layer is placed close to the light emitting layer, the triplet excitation energy generated in the phosphorescent layer is absorbed by the fluorescent layer. The host material (see Route Q1 in FIG. 10B) or the guest material (see Route Q2 in FIG. 10B) In other words, when the fluorescent and phosphorescent emitting layers are placed close to each other, This is because, in a normal fluorescent layer, the host material and As guest materials, materials with condensed aromatic hydrocarbon rings, such as anthracene skeletons, are used. This is because substances with condensed aromatic hydrocarbon rings tend to have low T1 levels. It is difficult to fabricate a fluorescent layer with good properties without using these skeletons. I did.

[0163] In addition, the triplet excited state has a long relaxation time, so the diffusion distance of excitons is long and the excitons are far from the fluorescent layer. Even if an exciton is generated inside the light-emitting layer, the exciton moves to the fluorescent light-emitting layer and is deactivated. It is possible that this may occur.

[0164] In the light-emitting device according to one embodiment of the present invention, the compound 132_f is formed in the light-emitting layer 130a. The triplet excitation energy is transferred to the nucleus, and the triplet excitation energy is converted into light emission. In FIG. 10B and FIG. 10C, a compound having TADF properties is used as compound 131_f. FIG. 10B shows an example using a material having T FH ≦T PH The compound This shows the case where the compound 135_p was used. In this case, , T by root Q1 FH The triplet excitation energy transferred to Route A1 and Route A It is converted to fluorescent light via route 2. In other words, route Q1 does not become an inactivation route. Similarly, when a phosphorescent compound is used for compound 131_f, T FH Move to The transferred triplet excitation energy is converted into fluorescence emission (Figure 7B, Route A). 19 (See reference). The singlet and triplet excitation energies generated in the phosphorescent light-emitting layer 130b are It can also be converted to phosphorescence via E1.

[0165] Furthermore, in the light-emitting device according to one embodiment of the present invention, the compound 132_f is a fluorescent compound having a protecting group. A photoactive material is used. Therefore, triplet excitation from compound 131_f by the Dexter mechanism Similarly, the phosphorescent host material shown in Route Q2 can be Triplet excitation energy transfer to fluorescent guest materials also occurs via the Dexter mechanism. Therefore, it is suppressed.

[0166] That is, in the light-emitting device according to one embodiment of the present invention, the fluorescent light-emitting layer and the phosphorescent light-emitting layer are adjacent to each other. Nevertheless, the triplet excitation energy of the phosphorescent layer can be suppressed. Both photoluminescence and phosphorescence can be efficiently obtained. By adjusting the amount of phosphorescence, the ratio of fluorescent and phosphorescent emission can be changed. By using materials that emit different colors, such as fluorescent materials and phosphorescent materials, it is possible to finely adjust the emitted color. It is possible to do so.

[0167] In addition, T FH ≦T PG When the triplet excitation energy of compound 136_p is By transferring to 31_f, the triplet excitation energy is not quenched, but phosphorescence emission is obtained. Therefore, in one aspect of the present invention, PG ≦T FH In particular, when a phosphorescent compound is used as the compound 131_f, Sea Urchin S FG ≦T FH The preferred structure is T PG ≦S FG ≦T FH In that case, Therefore, in the light-emitting device according to one embodiment of the present invention, the emission color of the fluorescent material is the same as that of the phosphorescent material. It is preferable that the wavelength is shorter than the emission color of the fluorescent material. It is preferable that the wavelength is shorter than the peak wavelength of the conductive material.

[0168] <Configuration Example 2 of the Light-Emitting Layer 130a and the Light-Emitting Layer 130b> FIG. 11B illustrates a light-emitting layer 13 of a light-emitting device 150 and a light-emitting device 152 according to an embodiment of the present invention. FIG. 11A shows an example of the correlation of energy levels in the light-emitting layers 130a and 130b. The light-emitting layer 130a and the light-emitting layer 130b are placed close to each other. The light-emitting layer 130a is made of the compound 131_f. and compound 132_f. The light-emitting layer 130b contains compound 135_p and compound 13 6_p, and compound 135_p consists of compound 135_1p and compound 135_2p In one embodiment of the present invention, compound 132_f is a fluorescent material having a protecting group. In addition, compound 131_f has the function of converting triplet excitation energy into luminescence. In the configuration example, compound 131_f is a material having TADF properties, and compound 136_p is a phosphorescent Compound 135_1p and compound 135_2p are a combination that forms an exciplex. That is, in this configuration example, the light emitting layer 130a is The configuration shown in the configuration example 1 of the light-emitting layer 30a is shown in the configuration example 2 of the light-emitting layer 130b. In addition, the route A1 to the route A3, the route E3 and the The energy transfer of E4 is as described above. For simplicity, the energy transfer of E4 is not shown in FIG. As the excitation level of the host material of the optical layer 130b, only the excitation level of the compound 135_p is shown. However, in reality, the singlet and triplet levels of compounds 135_1p and 135_2p are Each of them exists.

[0169] The notations and symbols in FIG. 11B are as follows: ·F-Host(131_f): Compound 131_f ·F-Guest(132_f): Compound 132_f ·P-Host(135_p): Compound 135_p ·P-Guest(136_p): Compound 136_p ·S FH :S1 level of compound 131_f T FH :T1 level of compound 131_f ·S FG :S1 level of compound 132_f T FG :T1 level of compound 132_f ·S PH : S1 level of compound 135_p T PH :T1 level of compound 135_p T PG :T1 level of compound 136_p ·S PE : S1 level of the exciplex T PE :T1 level of the exciplex

[0170] As shown in FIG. 11A, the light-emitting layer 130a and the light-emitting layer 130b are adjacent to each other, but as shown in FIG. In this configuration example, triplet excitation energy is generated in compound 131_f as in FIG. 10C. The material that has the function of converting light is a fluorescent material having a protecting group in compound 132_f. As a result, triplet excitation energy generated in the light-emitting layer 130b is quenched in the light-emitting layer 130b. This can prevent the leakage of the liquid (see route Q5 in FIG. 11B).

[0171] In this configuration example, ExTET is applied to the light-emitting layer 130b, which is a phosphorescent light-emitting layer. Therefore, in the light-emitting layer 130b, an exciplex consisting of the compound 135_1p and the compound 135_2p is formed. Most of the singlet and triplet excitons generated in the light-emitting layer 130b exist as exciplexes. Here, T PH ≧S PE (or T PE ) by selecting a material that is The singlet and triplet excitation energies of the exciplex are transferred to compound 135_p. In addition, the exciplex is in an excited state, so the exciplex does not move in the excited state (Routes Q3 and Q4 in Figure 11B). Therefore, energy transfer from one exciplex to another (Route Q6 in Figure 11B) does not occur. Therefore, the singlet excitation energy and triplet excitation energy of the phosphorescent layer using ExTET are The diffusion distance of energy is very small. Therefore, the singlet and triplet generated in the light-emitting layer 130b The singlet excitation energy is less likely to diffuse into the light-emitting layer 130a and is efficiently converted into phosphorescent light.

[0172] That is, the function of converting triplet excitation energy into light emission is compound 131_f in the fluorescent layer. In addition to using a fluorescent material having a protecting group in compound 132_f, By applying ExTET to the light-emitting layer, the triplet excitation energy can be further increased. It is possible to obtain a light-emitting device in which deactivation of the electron transport molecule is suppressed.

[0173] As the light-emitting device according to one embodiment of the present invention, the structure of the light-emitting layer 130a described with reference to FIG. 8 and the configuration example 1 of the light-emitting layer 130b described with reference to FIG. The combination of the light-emitting layer 130a and the light-emitting layer 130b illustrated in the configuration example 2 of the light-emitting layer 130b is illustrated. However, the light-emitting device according to one embodiment of the present invention is not limited to this. The light-emitting layer 130b is formed by using any one of the configurations described in the configuration examples 1 to 8 of the light-emitting layer 130a. As the light-emitting layer 130b, any one of the structures described in the structural examples 1 and 2 can be used. That is, the configuration of the light-emitting layer 130a and the configuration of the light-emitting layer 130b can be appropriately combined. Note that the light-emitting device of one embodiment of the present invention is not limited to these combinations.

[0174] As shown in FIG. 1B, a separation layer 120 is provided between the light-emitting layer 130a and the light-emitting layer 130b. The separation layer 120 can also absorb triplet excitation energy generated in the light-emitting layer 130b. The Dexter mechanism has the function of suppressing the transfer of energy to 30a. Since the thickness of the separation layer 120 is significantly less than 1 nm, the thickness of the separation layer 120 is preferably 1 nm or more. However, if the separation layer 120 is too thick, it becomes difficult to adjust the recombination region in the light-emitting device 152. Therefore, the thickness of the separation layer 120 is preferably 1 nm or more and 20 nm or less, and more preferably 2 nm or less. It is more preferable that the thickness is at most 10 nm.

[0175] <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.

[0176] <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, k h*→g is shown in Equation (1).

[0177]

number

[0178] 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.

[0179] Here, when the energy donor is the first material and the energy acceptor is the second material, In this case, if the emission colors of the first material and the second material are close to each other, then f' h (ν) and and ε g (ν) overlap becomes smaller (ε g (ν) is longer than the emission spectrum of the second material. wavelength side), so k h*→g However, the light emission of one embodiment of the present invention In the device, the concentration of energy donors in the light-emitting layer can be increased as described above. Therefore, the value of R in formula (1) can be increased, and k h*→g Suppressing the decline of Therefore, in the light-emitting device according to one embodiment of the present invention, the emission color is close to that of the energy donor. A fluorescent material having the following formula can be used as a light-emitting material. The device can be used even if the emission colors of the energy donor and energy acceptor are different. It is possible.

[0180] <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.

[0181]

number

[0182] 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.

[0183] 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.

[0184]

number

[0185] 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.

[0186] <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.

[0187] 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 at the longest wavelength. Since the direct transition from the singlet ground state to the triplet excited state is forbidden in the material, The molar extinction coefficient associated with the triplet excited state in the second material is negligible. Therefore, the triplet excited state of the first material is transferred to the second material by the Förster mechanism. The energy transfer process to the singlet excited state of the second material is negligible. Only the process needs to be considered.

[0188] 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.

[0189] 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 the overlap of the absorption bands that appear at different wavelengths.

[0190] 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.

[0191] 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

[0192] 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.

[0193] 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 energy is emitted by photoactive compounds, exciplexes, or TADF materials. The first material, which can convert light, transmits 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 material) to promote reverse intersystem crossing from the triplet excited state to the singlet excited state, The excited lifetime τ of the triplet excited state of the first material can be shortened. From the triplet excited state of a phosphorescent material or an exciplex using a phosphorescent material to the singlet ground state This can promote the transition of the triplet excited state of the first material and shorten the excited lifetime τ of the triplet excited state of the first material. As a result, the triplet excited state of the first material is converted to the triplet excited state of the fluorescent material (second material). This can reduce the efficiency of energy transfer in the Dexter mechanism to the acetylcholinesterase state.

[0194] 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 130a can be suppressed. As a result, a light-emitting device with high luminous efficiency can be provided.

[0195] <Material> Next, the components of the light-emitting device according to one embodiment of the present invention will be described in detail below. cormorant.

[0196] <Light-emitting layer 130a> The materials that can be used for the light-emitting layer 130a are described below. In one embodiment of the light-emitting device, the light-emitting layer 130a includes a layer that converts triplet excitation energy into light emission. An energy acceptor having a functional group and an energy donor having a luminophore and a protecting group are As a material that has the function of converting triplet excitation energy into light emission, TADF Examples of materials that can be used for compound 131 include: Materials applicable to compound 131_f and compound 132 are also applicable to compound 132_f. It is possible.

[0197] 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.

[0198] 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.

[0199] 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.

[0200] 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. Groups with one or more carbon atoms, such as sec-butyl, tert-butyl, pentyl, and hexyl groups Alkyl groups with an alkyl group of 7 or less, cyclopentyl groups, cyclohexyl groups, cycloheptyl groups, 8, 9,10-trinorbornanyl group, and other cycloalkyl groups having 5 to 7 carbon atoms; Aryl groups having 6 to 12 carbon atoms, such as phenyl, naphthyl, and biphenyl groups, Some examples include:

[0201] 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.

[0202] 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.

[0203] 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 the luminophore and the diarylamino group are Structures having bonds at the nitrogen atom are preferred.

[0204] In addition, the emission color can be adjusted by binding two or more diarylamino groups to the luminophore. In addition, it is possible to obtain a fluorescent material with a high quantum yield. It is preferable to bond the luminophore to a symmetric position. The material may be a fluorescent material having a high efficiency.

[0205] In addition, instead of directly introducing a protecting group into the luminophore, the aryl group of the diarylamino group is A protecting group may be introduced via the group. By adopting this structure, a protecting group is formed so as to cover the luminophore. Since the groups can be arranged, the distance between the host material and the luminophore can be increased from any direction. In addition, when the protecting group is not directly bonded to the luminophore, the protecting group is preferably It is preferable to introduce four or more per one luminophore.

[0206] As shown in FIG. 3, at least one of the atoms constituting the multiple protecting groups is a luminophore. That is, the fused aromatic ring or the fused heteroaromatic ring is located directly on one side thereof, and a plurality of protecting groups are At least one of the atoms constituting the condensed aromatic ring or the condensed heteroaromatic ring is on the other side of the The preferred configuration is one in which the sensor is 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 a diphenyl and each of the phenyl groups in the two or more diphenylamino groups is independently It has protecting groups at the 3- and 5-positions.

[0207] With this structure, as shown in FIG. 4, the 3- or 5-position of the phenyl group can be The configuration in which the protecting group is located directly above the condensed aromatic ring or condensed heteroaromatic ring that is the luminophore is As a result, the fused aromatic ring or the fused heteroaromatic ring can be arranged above and below the plane of the ring. This effectively covers the surface of the cell, suppressing the energy transfer caused by the Dexter mechanism. do.

[0208] The energy acceptor material as described above may be represented by the following general formula (G1) or G2) can be suitably used.

[0209] [ka]

[0210] 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;

[0211] 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.

[0212] 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.

[0213] In addition, in the general formula (G2), the protecting group is a quinacryloyl group, which is a luminophore, via an aromatic hydrocarbon group. By using this structure, the protecting group is arranged to cover the luminophore. Therefore, energy transfer via the Dexter mechanism can be suppressed. In addition, the luminophore may have a protecting group that is directly bonded to the luminophore.

[0214] The energy acceptor material is represented by the following general formula (G3) or (G4): Organic compounds that can be used in the present invention can be suitably used.

[0215] [ka]

[0216] 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 12 carbon atoms; R represents one of the groups 1 , R 3 , R 6 and R 8 are each independently hydrogen, a carbon number of 3 an alkyl group having from 1 to 10 carbon atoms; a substituted or unsubstituted cycloalkyl group having from 3 to 10 carbon atoms; a trialkylsilyl group having from 3 to 12 carbon atoms.

[0217] It is also preferred that the protecting group is bonded to the luminophore via a phenylene group. By this, the protecting group can be placed to cover the luminophore, and thus the Dexter mechanism can be realized. In addition, the luminophore and the protecting group are connected to the phenylene group. When the phenylene group is bonded to the phenylene group via a protecting group, the protecting group can be represented by the general formula (G3) or ( As shown in G4), the two protecting groups are preferably attached at the meta position to the phenylene group. This structure allows the luminophores to be covered efficiently, making it possible to obtain a Dexter The organic compound represented by the general formula (G3) can suppress the energy transfer by the mechanism. An example of such a product is the above-mentioned 2tBu-mmtBuDPhA2Anth. That is, in one embodiment of the present invention, general formula (G3) is a particularly preferred example.

[0218] The energy acceptor material is an organic compound represented by the following general formula (G5): The material can be suitably used.

[0219] [ka]

[0220] 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 the following 12 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 12 carbon atoms, and or an unsubstituted aryl group having 6 to 25 carbon atoms.

[0221] 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 substituent may be an alkyl group having 1 to 10 carbon atoms, or an alkyl group having 3 to 10 carbon atoms. a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms; Examples of the alkyl group include trialkylsilyl groups having 3 to 12 carbon atoms.

[0222] 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.

[0223] 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 (284). The compounds represented by the structural formulas (102) to (105) are not limited to these. The compounds shown in (200) to (284) are fluorescent materials for a light-emitting device according to one embodiment of the present invention. However, the fluorescent material is not limited to these.

[0224] [ka]

[0225] [ka]

[0226] [ka]

[0227]

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[0228]

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[0229]

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[0230]

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[0231]

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[0232]

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[0233]

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[0234]

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[0235]

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[0236]

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[0238] [ka]

[0239] [ka]

[0240] [ka]

[0241] [ka]

[0242] [ka]

[0243] [ka]

[0244] [ka]

[0245] [ka]

[0246] In addition, one of the materials that can be suitably used as the fluorescent material for the light-emitting device of one embodiment of the present invention is Examples are shown in structural formulas (100) and (101). Note that the fluorescent material is not limited to these. .

[0247] [ka]

[0248] When compound 133 functions as an energy donor, for example, using TADF materials It is preferable that the energy difference between the S1 level and the T1 level of the compound 133 is small. Specifically, it is greater than 0 eV and equal to or less than 0.2 eV.

[0249] When compound 133 is a TADF material, it has a structure that has a hole transporting property and an electron transporting property. Alternatively, compound 133 may have a π-electron rich backbone or aromatic It is preferable that the compound has an aromatic amine skeleton and a π-electron deficient skeleton. In addition, the donor-acceptor excited state is easily formed in the molecule of compound 133. In order to strengthen both donor and acceptor properties within the molecule, the structure is designed to have a backbone with electron transport properties and a hole transport property. It is preferable that the structure has a structure in which the skeleton having transport properties is directly bonded to the π electron. The structure has a structure in which an excess skeleton or an aromatic amine skeleton is directly bonded to a π-electron deficient skeleton. It is preferable to strengthen both donor and acceptor properties in the molecule. Region where HOMO molecular orbitals are distributed and region where LUMO molecular orbitals are distributed The overlap between the singlet excited energy level and the triplet excited energy level of compound 133 can be reduced. It is possible to reduce the energy difference with the excited energy level. This makes it possible to maintain the triplet excited energy level of 3 at a high energy.

[0250] When a TADF material is composed of one type of material, for example, the following material can be used: can.

[0251] First, fullerene and its derivatives, acridine derivatives such as proflavine, and eosin are listed. In addition, magnesium (Mg), zinc (Zn), cadmium (Cd), tin (S n), platinum (Pt), indium (In), or palladium (Pd) Examples of the metal-containing porphyrin include protoporphyrin. Porphyrin-tin fluoride complex (SnF2(Proto IX)), mesoporphyrin-fluoride Tin complex (SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (Sn F2 (Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride Complex (SnF2(Copro III-4Me)), Octaethylporphyrin-fluoride Tin complex (SnF2(OEP)), etioporphyrin-tin fluoride complex (SnF2(E tio I)), octaethylporphyrin-platinum chloride complex (PtCl2OEP), etc. Can be obtained.

[0252] [ka]

[0253] In addition, as a thermally activated delayed fluorescent material composed of one kind of material, Heterocyclic compounds having either or both of a π-electron deficient skeleton and a π-electron deficient skeleton can also be used. The compound is 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3 -a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ) , 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazo {4,6-diphenyl-1,3,5-triazine (abbreviation: P CCzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4 ,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4-(5 -Phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl Nyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl -9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN ), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfon DMAC-DPS, 10-phenyl-10H,10'H-spiro[acrylidin 4-(9'-phenyl-9,9'-anthracene)-10'-one (abbreviation: ACRSA), Nyl-3,3'-bi-9H-carbazol-9-yl)benzofuro[3,2-d]pyrimidinyl 4-[4-(9'-phenyl-3,3'-bi-9H -carbazol-9-yl)phenyl]benzofuro[3,2-d]pyrimidine (abbreviation: 4 PCCzPBfpm), 9-[3-(4,6-diphenyl-1,3,5-triazine-2 -yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mP The heterocyclic compound includes a π-electron-rich heteroaromatic ring and Since it has a π-electron-deficient heteroaromatic ring, it has high electron transport properties and hole transport properties, which is preferable. Among the skeletons that have a π-electron deficient heteroaromatic ring, the pyridine skeleton and the diazine skeleton (pyridine The lysine skeleton, pyrazine skeleton, pyridazine skeleton, and triazine skeleton are stable and reliable. In particular, benzofuropyrimidine skeleton and benzothienopyrimidine skeleton are preferred. In addition, the benzofuropyrazine and benzothienopyrazine skeletons have high acceptor properties and are reliable. Among the skeletons having a π-electron-rich heteroaromatic ring, acrylic azine skeleton, phenoxazine skeleton, phenothiazine skeleton, furan skeleton, thiophene skeleton, and Since the pyrrole skeleton is stable and reliable, it is preferable that the compound has at least one of the skeletons. As the furan skeleton, a dibenzofuran skeleton is preferable, and as the thiophene skeleton, a dibenzofuran skeleton is preferable. The benzothiophene skeleton is preferable. The pyrrole skeleton is preferably an indole skeleton. Carbazole skeleton, bicarbazole skeleton, 3-(9-phenyl-9H-carbazole In addition, a π-electron-rich heteroaromatic ring is particularly preferred. A substance in which a ring and a π-electron-deficient heteroaromatic ring are directly bonded is a donor for the π-electron-rich heteroaromatic ring. The acceptor properties of the π-electron-deficient heteroaromatic rings are both strong, and the singlet excited state and triplet excited state are This is particularly preferred because the difference in the levels of the first excited states is small. Alternatively, an aromatic ring having an electron-withdrawing group such as a cyano group may be used. As the molecular excess skeleton, an aromatic amine skeleton, a phenazine skeleton, etc. can be used. π-electron deficient skeletons include xanthene skeleton, thioxanthene dioxide skeleton, oxanthene dioxide skeleton, Diazole skeleton, triazole skeleton, imidazole skeleton, anthraquinone skeleton, phenyl Boron-containing skeletons such as borane and boranthrene, nitriles such as benzonitrile and cyanobenzene Aromatic or heteroaromatic rings with aryl or cyano groups, or carbonyl skeletons such as benzophenone , phosphine oxide skeleton, sulfone skeleton, etc. can be used. A π-electron deficient heteroaromatic ring is used in place of at least one of the π-electron deficient heteroaromatic ring and the π-electron rich heteroaromatic ring. type backbone and π-electron rich type backbone can be used.

[0254] [ka]

[0255] When compound 133 does not have the function of converting triplet excitation energy into luminescence, compound 1 As for the combination of 31 and compound 133 or compound 131 and compound 134, they are mutually excitonic complexes. A combination that forms a bond is preferred, but there is no particular limitation. It is preferable that one of the aromatic rings has a function of transporting holes and the other has a function of transporting holes. It is preferred that one of the rings has a π-electron rich heteroaromatic ring and the other has a π-electron rich heteroaromatic ring.

[0256] 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.

[0257] In addition, the following hole transporting materials and electron transporting materials can be used.

[0258] 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.

[0259] 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).

[0260] 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.

[0261] 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.

[0262] 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.

[0263] 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.

[0264] 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.

[0265] 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: PCBNB) B) 4-phenyldiphenyl-(9-phenyl-9H-carbazol-3-yl)amine N,N'-bis(9-phenylcarbazol-3-yl)- N,N'-Diphenylbenzene-1,3-diamine (abbreviation: PCA2B), N,N',N ''-Triphenyl-N,N',N''-tris(9-phenylcarbazol-3-yl) ) Benzene-1,3,5-triamine (abbreviation: PCA3B), N-(4-biphenyl)- N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carba PCBiF, N-(1,1'-biphenyl-4-yl)- N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl 9,9-Dimethyl-N- Phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluor PCBAF, N-phenyl-N-[4-(9-phenyl- 9H-carbazol-3-yl)phenyl]spiro-9,9'-bifluorene-2-amine PCBASF, 2-[N-(9-phenylcarbazol-3-yl)-N- Phenylamino]spiro-9,9'-bifluorene (abbreviation: PCASF), 2,7-bis [N-(4-diphenylaminophenyl)-N-phenylamino]-spiro-9,9'- Bifluorene (abbreviation: DPA2SF), N-[4-(9H-carbazol-9-yl)fluorene N,N'-phenyl]-N-(4-phenyl)phenylaniline (abbreviation: YGA1BP), Bis[4-(carbazol-9-yl)phenyl]-N,N'-diphenyl-9,9-di Aromatic amine compounds such as methylfluorene-2,7-diamine (abbreviation: YGA2F) Also, 3-[4-(1-naphthyl)-phenyl]-9-phenyl can be used. -9H-Carbazole (abbreviation: PCPN), 3-[4-(9-phenanthryl)-phenyl PCPPn, 3,3'-bis(9- phenyl-9H-carbazole) (abbreviation: PCCP), 1,3-bis(N-carbazolyl )benzene (abbreviation: mCP), 3,6-bis(3,5-diphenylphenyl)-9-phenyl Nylcarbazole (abbreviation: CzTP), 4-{3-[3-(9-phenyl-9H-fluoro mmDBFFLBi-I I), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (Abbreviation: DBF3P-II), 1,3,5-tri(dibenzothiophen-4-yl)-benzyl DBT3P-II, 2,8-diphenyl-4-[4-(9-phenyl- 9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-I II), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-fluor (abbreviation: DBTFLP-IV), 4-[3-(triphenylene -2-yl)phenyl]dibenzothiophene (abbreviation: mDBTPTp-II) and other amines compounds, carbazole compounds, thiophene compounds, furan compounds, fluorene compounds, The materials mentioned herein include phenylene compounds, phenanthrene compounds, etc. is mainly 1×10 -6 cm 2 A material that has a hole mobility of at least / Vs. Substances other than these may be used as long as they have a higher hole transporting property than the above.

[0266] 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). A π-electron deficient heteroaromatic compound or a metal complex can be used. Quinoline, benzoquinoline, oxazole, or thiazole ligands Metal complexes having the same, oxadiazole derivatives, triazole derivatives, phenanthroline derivatives Examples of the compound include conductors, pyridine derivatives, bipyridine derivatives, and pyrimidine derivatives.

[0267] 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 nyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[ 3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2 Heterocyclic compounds with diazine skeletons such as 2-{4-[3-(N-phenyl- 9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6 -Diphenyl-1,3,5-triazine (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.

[0268] Compound 133 or compound 134 is a material capable of forming an exciplex with compound 131. Specifically, it is preferable to use the hole transport material and the electron transport material described above. In this case, compound 131 and compound 133 or compound 131 and compound 134 can be used. The emission peak of the exciplex formed by Compound 131 and Compound 133 or Compound 131 were placed so that the absorption bands of the two compounds overlap. It is preferable to select Compound 134 and Compound 132 (fluorescent material). As a result, a light emitting device with dramatically improved luminous efficiency can be obtained.

[0269] In addition, a phosphorescent material can be used as the compound 133. , iridium, rhodium, or platinum-based organometallic complexes or metal complexes. In addition, platinum complexes and organic iridium complexes having porphyrin ligands are also included, among which For example, organic iridium complexes such as iridium orthometal complexes are preferred. The ligands that can be used for the polymerization include 4H-triazole ligands, 1H-triazole ligands, imidazole ligands, and tetraazolidine ligands. Zole ligand, pyridine ligand, pyrimidine ligand, pyrazine ligand, or isoquinoline ligand In this case, compound 133 (phosphorescent material) is a triplet MLCT (Metal to Ligand Charge Transfer) transition absorption band The emission peak of compound 133 is at the longest wavelength ( Compound 133 and Compound 132 (fluorescent material) were added so that the absorption bands of the two compounds overlap with each other. This results in a light-emitting device with dramatically improved luminous efficiency. Even if compound 133 is a phosphorescent material, compound 131 and It is acceptable to form an exciplex. When an exciplex is formed, the phosphorescent compound emits light at room temperature. It is not necessary to form an exciplex that emits light at room temperature. In this case, for example, Ir (ppz)3 and the like can be used as the phosphorescent compound.

[0270] Examples of substances having a blue or green emission peak include tris{2-[5-(2 -methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazo 3-yl-κN 2 ]phenyl-κC}iridium(III) (abbreviation: Ir(mpp tz-dmp)3), tris(5-methyl-3,4-diphenyl-4H-1,2,4-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(III) (abbreviation: Ir(iPr5btz)3), a 4H-triazole skeleton and organometallic iridium complexes having tris[3-methyl-1-(2-methylphenyl) -5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: Ir (Mptz1-mp)3), tris(1-methyl-5-phenyl-3-propyl-1H- 1,2,4-Triazolate)iridium(III) (abbreviation: Ir(Prptz1-Me) 3) and fac-triazole-based organometallic iridium complexes. S[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole] Iridium(III) (abbreviation: Ir(iPrpmi)3), tris[3-(2,6-dimethyl phenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(I II) Imidazole skeleton-containing compounds such as Ir(dmpimpt-Me)3 Organic metal iridium complexes and bis[2-(4',6'-difluorophenyl)pyridinato N,C 2’ ]Iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FI r6), Bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ ]Ili Dium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis (Trifluoromethyl)phenyl]pyridinato-N,C 2’}Iridium(III) pico Ir(CF3ppy)2(pic) (fluorophenyl)pyridinato-N,C 2’ ]Iridium(III) acetylacetonate (abbreviation: FIr(acac)) Among the above, 4H-triazole is an organometallic iridium complex. Nitrogen-containing five-membered heterocyclic skeletons such as 1H-triazole skeleton and imidazole skeleton The organometallic iridium complex has high triplet excitation energy and is highly reliable and has excellent luminescence efficiency. It is particularly preferred because it is also excellent in

[0271] 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.

[0272] 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.

[0273] In addition, materials that can be used as the above-mentioned energy donor include metal halides. The metal perovskites are represented by the following general formula (g1 ) to (g3).

[0274] (SA)MX3:(g1) (LA)2(SA) n-1 M n X 3n+1 :(g2) (PA)(SA) n-1 M n X3 n+1 :(g3)

[0275] In the above general formula, M represents a divalent metal ion, and X represents a halogen ion.

[0276] Specifically, divalent cations such as lead and tin are used as divalent metal ions.

[0277] Specifically, the halogen ions used are anions of chlorine, bromine, iodine, fluorine, etc. I can.

[0278] In addition, n represents an integer of 1 to 10, but in the general formula (g2) or (g3), In the case where n is greater than 10, the property is that of a metal halide represented by the general formula (g1): It is close to perovskites.

[0279] Also, LA is R 30 -NH3 + It represents an ammonium ion represented by the formula:

[0280] General formula R 30 -NH3 + In the ammonium ion represented by R 30 has 2 to 4 carbon atoms 20 alkyl groups, aryl groups, and heteroaryl groups, or a group having 2 to 20 carbon atoms an alkyl group, an aryl group, or a heteroaryl group, and an alkylene group having 1 to 12 carbon atoms a combination of a vinylene group, an arylene group having 6 to 13 carbon atoms, and a heteroarylene group; In the latter case, the alkylene group, the arylene group, and the heteroarylene group are each a group consisting of a plurality of groups. The alkylene groups may be linked together, and a plurality of the same groups may be used. When a plurality of alkyl groups, vinylene groups, arylene groups, and heteroarylene groups are connected, The total number of aryl, vinylene, arylene and heteroarylene groups is 35 or less. is preferred.

[0281] SA is a monovalent metal ion or R 31 -NH3 + It is expressed as R 31 Carbon number 1 to 6 represents an ammonium ion, which is an alkyl group.

[0282] PA is also NH3 + -R 32 -NH3 + or NH3 + -R 33 -R 34 -R 35 -NH3 + or a portion of a branched polyethyleneimine having an ammonium cation; The valence of the part is +2. The charges in the general formula are almost balanced. .

[0283] Here, the charge of the metal halide perovskites is calculated by the above formula: It is not necessary to strictly balance the temperature, but it is sufficient if the neutrality of the entire material is roughly maintained. There are localized free ammonium ions, free halogen ions, and impurity ions in the material. Other ions such as may be present, which may neutralize the charge. In addition, local neutrality may not be maintained on the surfaces of particles and films, or on grain boundaries of crystals. Neutrality does not necessarily have to be maintained in all locations.

[0284] In addition, (LA) in the above formula (g2) can be, for example, the following general formulas (a-1) to (a-1 1), and substances represented by general formulas (b-1) to (b-6), etc. can be used.

[0285] [ka]

[0286] [ka]

[0287] In addition, (PA) in the above general formula (g3) is typically represented by the following general formula (c-1), (c -2) and (d) and a branched polymer having an ammonium cation It represents part or all of a compound such as triethyleneimine, and has a +2 charge. These polymers may have charge neutralization across multiple unit cells and may have different The charge of one unit cell is neutralized by one charge of each of the two polymer molecules. In some cases, this is also the case.

[0288] [ka]

[0289] [ka]

[0290] However, in the above general formula, R 20 represents an alkyl group having 2 to 18 carbon atoms; R 21 , R 2 2 and R 23 represents hydrogen or an alkyl group having 1 to 18 carbon atoms; R 24 is the following structural formula and the general formula (R 24 -1)~(R 24 -14). Also, R 25 and R 26 teeth Each of X independently represents hydrogen or an alkyl group having 1 to 6 carbon atoms. A combination of monomer units A and B represented by any one of the combinations of (d-1) to (d-6) It represents a structure that contains u A's and v B's. The order of A and B is In addition, m and l are each independently an integer of 0 to 12, and t is an integer of 1 to In addition, u is an integer from 0 to 17, v is an integer from 1 to 18, and u+v is an integer from 1 to 18.

[0291] [ka]

[0292] Note that these are merely examples, and the substances that can be used as (LA) and (PA) are as follows: is not limited to.

[0293] A three-dimensional metal halide having the composition (SA)MX3 represented by the general formula (g1) Perovskites have a metal atom M at the center and halogen atoms at the six vertices. The octahedral structure is arranged three-dimensionally, sharing the halogen atoms at each vertex, to form a skeleton. The structural unit of this regular octahedron with halogen atoms at each vertex is called a perovskite unit. This perovskite unit exists in isolation, forming a zero-dimensional structure. Linear structures connected one-dimensionally via halogen atoms at the vertices, and sheets connected two-dimensionally There are structures with perovskite units arranged in two dimensions, and structures with three-dimensional connections. Complex two-dimensional structures can also be formed by stacking multiple layers of interlocking sheet-like structures. There are also more complex structures. The general term for all structures that contain these perovskite units is Hereinafter, the term "metal halide perovskites" will be used.

[0294] The light-emitting layer 130a may be made up of two or more layers. When the first light-emitting layer and the second light-emitting layer are laminated in this order from the hole transport layer side to form the light-emitting layer 130a, 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. There is a structure in which a substance having an electron transport property is used as a material.

[0295] In the light-emitting layer 130a, the compounds 131, 132, 133 and In this case, the compound 131 and the compound 132 may have a material other than the compound 134 (compound 135). In order for compound 133 (or compound 134) to efficiently form an exciplex, compound 1 The HOMO level of either compound 31 or compound 133 (or compound 134) is higher than that of the light-emitting layer 130. The material in the light-emitting layer 130a has the highest HOMO level, and the other material in the light-emitting layer 130b has the highest LUMO level. It is preferable that the LUMO level of the material is the lowest of all the materials. By using this as a ligand, the reaction of compound 131 and compound 135 to form an exciplex can be suppressed. This can be done.

[0296] 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.

[0297] There is no particular limitation on the material (compound 135) that can be used for the light-emitting layer 130a. For example, tris(8-quinolinolato)aluminum(III) (abbreviation: Alq), Tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), Bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq 2) 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: ZnPB O), bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBT Z), 2-(4-biphenylyl)-5-(4-tert-butylphenyl )-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(p-ter t-Butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: O XD-7), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butyl) phenyl)-1,2,4-triazole (abbreviation: TAZ), 2,2',2''-(1,3, 5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: T PBI), Bathophenanthroline (abbreviation: BPhen), Bathocuproine (abbreviation: BC P), 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 N-(spiro-9,9 '-Bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB) Examples of aromatic amine compounds include anthracene derivatives and phenanthrene derivatives. Polycyclic aromatic hydrocarbons such as pyrene derivatives, chrysene derivatives, and dibenzo[g,p]chrysene derivatives Aromatic compounds include 9,10-diphenylanthracene (abbreviation: DPA nth), N,N-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl 10-phenyl]-9H-carbazol-3-amine (abbreviation: CzA1PA), -9-Anthryl)triphenylamine (abbreviation: DPhPA), 4-(9H-carbazol (abbreviation)-4'-(10-phenyl-9-anthryl)triphenylamine : YGAPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthryl) Phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), N,9-diphenyl -N-{4-[4-(10-phenyl-9-anthryl)phenyl]phenyl}-9H -Carbazole-3-amine (abbreviation: PCAPBA), N,9-diphenyl-N-(9, 10-Diphenyl-2-anthryl)-9H-carbazol-3-amine (abbreviation: 2PC APA), 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 Nyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: DPCzPA), 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 2 -tert-Butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDN A), 9,9'-bianthryl (abbreviation: BANT), 9,9'-(stilbene-3,3' -diyl)diphenanthrene (abbreviation: DPNS), 9,9'-(stilbene-4,4'- Diphenyl)phenanthrene (abbreviation: DPNS2), 1,3,5-tri(1-pyrenyl)be Among these and other known substances, Therefore, the energy gap is larger than that of the above compounds 131 and 132. One or more types of substances having a gap may be selected and used.

[0298] <Light-emitting layer 130b> In the light-emitting layer 130b of the light-emitting device according to one embodiment of the present invention, a host material and a triplet excitation energy The guest material (compound 136 and Compound 136_p) includes TADF materials, exciplexes, phosphorescent materials, etc. However, TADF materials and phosphorescent materials are preferred, and phosphorescent materials are more preferred. The TADF material and phosphorescent material can be used as the energy donor of the optical layer 130a. It can be used.

[0299] The host material of the light-emitting layer 130b (compound 135 and compound 135_p) is the above-mentioned positive A hole transporting material or an electron transporting material can be used. It is possible to use a material with a higher hole transport capacity than electrons, and the -6 cm 2 / Vs or more It is preferable that the material used for the light-emitting layer 130a has a hole mobility. The aromatic amine and carbazole derivatives mentioned above are used as hole transport materials that can In addition, as the electron transporting material, a material having a higher electron transporting property than a hole transporting property is used. It can be 1×10 -6 cm 2 The material has an electron mobility of ≥ 100 / Vs. As a compound that easily receives electrons (a material having electron transport properties), a nitrogen-containing complex is preferable. Examples of the aromatic heteroaromatic compound include π-electron deficient heteroaromatic compounds such as aromatic aromatic compounds and metal complexes. Specifically, quinoline, which is listed as an example of an electron transport material that can be used in the light-emitting layer 130a, Ligands containing benzoquinoline, oxazole, or thiazole ligands In addition, oxadiazole derivatives, triazole derivatives, phenazolyl derivatives, and other metal complexes are also available. Examples include aryl amine derivatives, pyridine derivatives, bipyridine derivatives, and pyrimidine derivatives. Also, 1×10 -6 cm 2 It is preferable that the material has an electron mobility of .beta. / Vs or more. It is.

[0300] The host material of the light-emitting layer 130b is made of two materials (compound 135_ 1p and compound 135_2p), wherein the two materials form an exciplex. Therefore, either compound 135_1p or compound 135_2p is more preferable. It is preferable to use a hole transporting material for the first layer and an electron transporting material for the second layer. This makes it possible to apply ExTET to the light-emitting layer 130b.

[0301] ≪Separation layer 120≫ The separation layer 120 is a layer through which triplet excitation energy generated in the light-emitting layer 130b is transferred to the light-emitting layer 130a. The separation layer 120 has a function of suppressing the formation of a luminous layer 130a and a luminous layer 130b. Therefore, in order to efficiently emit light from the light-emitting layers 130a and 130b, It is preferable that the separation layer 120 has carrier (electron and / or hole) transport properties. For the separation layer 120, the above-mentioned hole transporting material and electron transporting material can be used.

[0302] In addition, the separation layer 120 may be made of two or more materials. When the material is composed of the above materials, it is preferable that the material contains both a hole transporting material and an electron transporting material. In addition, when the separation layer 120 contains both a hole transport material and an electron transport material, the mixture ratio It is possible to easily control the carrier balance by using the hole transporting property. The material:electron transporting material ratio is preferably in the range of 1:9 to 9:1 (weight ratio). By having such a structure, the carrier balance can be easily controlled, and the carrier recombination can be easily controlled. In addition, the separation layer 120 can easily control the region where the hole transport material and the electron transport material are mixed. In the case where both a hole transport material and an electron transport material are included, the hole transport material and the electron transport material are a compound that forms an exciplex. A combination is preferable.

[0303] In addition, the T1 level of the material used in the separation layer 120 is greater than or equal to the T1 level of the host material used in the light-emitting layer 130b. Such a level is preferable because it is possible to suppress diffusion of triplet excitons generated in the light-emitting layer 130b. In addition, the T1 level of the host material used in the light-emitting layer 130b ≧ the T1 level of the material used in the separation layer 120 The level may be equal to or greater than the T1 level of the energy donor used in the light emitting layer 130a. In this case, triplet excitons generated in the light-emitting layer 130b move to the light-emitting layer 130a and are converted into fluorescent light. can be.

[0304] The electrodes 101 and 102 inject holes and electrons into the light-emitting layers 130a and 130b. The electrodes 101 and 102 are made of metals, alloys, conductive compounds, and the like. It can be formed by using a mixture or laminate of these. A typical example is silver (Ag), tungsten, chromium, molybdenum, copper, Transition metals such as titanium, alkali metals such as lithium (Li) and cesium, calcium, Group 2 metals such as magnesium (Mg) can be used. Rare earth metals such as yttrium (Yb) may also be used. Examples of conductive compounds that can be used include MgAg, AlLi, etc. For example, indium tin oxide (ITO), Indium tin oxide containing silicon or silicon oxide (abbreviation: ITSO), indium zinc oxide Indium Zinc Oxide, indium containing tungsten and zinc Examples of conductive compounds include inorganic carbon such as graphene. As described above, a plurality of these materials may be laminated to form an electric One or both of the pole 101 and the electrode 102 may be formed.

[0305] The light emitted from the light-emitting layers 130a and 130b is incident on the electrodes 101 and 102. Therefore, the current is taken out through one or both of electrodes 101 and 102. At least one of the conductive materials has a function of transmitting visible light. The visible light transmittance is 40% or more and 100% or less, preferably 60% or more and 100% or less. and its resistivity is 1×10 -2 Conductive materials with a resistance of Ω cm or less are also included. The electrode for extracting light is a conductive material having a function of transmitting light and a function of reflecting light. The conductive material may be made of a material having a visible light reflectance of 20% or more and 80% or less. % or less, preferably 40% to 70%, and the resistivity is 1×10 -2 Ω·c The electrode that extracts the light is made of a light-transmitting material such as a metal or alloy. When using a low-cost material, the thickness must be such that visible light can pass through (for example, 1 nm to 10 nm). One or both of the electrodes 101 and 102 may be formed to a thickness of 100 nm.

[0306] 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.

[0307] 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.

[0308] <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).

[0309] 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.

[0310] 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 130a are In addition, aromatic hydrocarbons and stilbene derivatives can be used. A conductor or the like can be used. The hole transport material may be a polymer compound. .

[0311] 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.

[0312] 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.

[0313] 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.

[0314] <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. The hole injection layer 1 has a function of transporting holes to the light-emitting layer 130a or the light-emitting layer 130b. It is preferred that the HOMO level of the 11 be the same as or close to the HOMO level of the 11 .

[0315] 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.

[0316] ≪Electron transport layer≫ The electron transport layer 118 is connected to the other of the pair of electrodes (electrode 101 or The function of transporting electrons injected from the electrode 102 to the light-emitting layer 130a or the light-emitting layer 130b is As the electron transporting material, a material having a higher electron transporting property than a hole transporting property can be used. 1×10 -6 cm 2 It is preferable that the material has an electron mobility of .beta. / Vs or more. Nitrogen-containing heteroaromatic compounds are examples of compounds that can easily accept electrons (materials with electron transport properties). Examples of the compounds that can be used include π-electron deficient heteroaromatic compounds and metal complexes. The quinoline ligand, benzoyl group, and the like mentioned above as electron transport materials that can be used in the light-emitting layer 130a may be used. Metal complexes containing oxazole, oxazole, or thiazole ligands are In addition, oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, etc. conductors, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, etc. 1×10 -6 cm 2 It is preferable that the substance has an electron mobility of 1 / Vs or more. Any other substance that has a higher electron transporting property than holes can be used as the electron transport layer. The electron transport layer 118 may be a single layer or may be two or more layers made of the above-mentioned materials. It may be laminated on top.

[0317] In addition, electron carriers are generated between the electron transport layer 118 and the light-emitting layer 130a or the light-emitting layer 130b. The layer for controlling the movement of electron carriers may be provided as described above. This layer is made by adding a small amount of a substance with high electron trapping properties to a material with high electron transport properties. By suppressing the movement of the carriers, it becomes possible to adjust the carrier balance. Such a structure can cause problems such as electron penetration through the light-emitting layer (e.g., It is highly effective in suppressing the decline in the life span of young children.

[0318] ≪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 .

[0319] 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.

[0320] 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.

[0321] 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.

[0322] 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.

[0323] 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.

[0324] <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.

[0325] 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 light-emitting device and an optical element can be fabricated using the same. 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 element.

[0326] For example, in one embodiment of the present invention, a light-emitting device can be formed using various substrates. The type of substrate is not particularly limited. An example of the substrate is a semiconductor substrate (e.g. For example, single crystal substrate or silicon substrate), SOI substrate, glass substrate, quartz substrate, plastic Substrate, metal substrate, stainless steel substrate, substrate with stainless steel foil, Tungsten substrate, substrate with tungsten foil, flexible substrate, lamination film Materials that contain fibrous materials such as cellulose nanofiber (CNF), paper, or base film Examples of glass substrates include barium borosilicate glass and aluminoborosilicate glass. Glass, soda lime glass, etc. Flexible substrates, laminated films, base film Examples of such films include polyethylene terephthalate (P ET), polyethylene naphthalate (PEN), polyethersulfone (PES), poly There are plastics such as tetrafluoroethylene (PTFE). Examples of the resin include acrylic resin. Examples of the resin include polypropylene, polyethylene, etc. Examples include styrene, polyvinyl fluoride, or polyvinyl chloride. Examples of the material include polyamide, polyimide, aramid, epoxy, inorganic vapor deposition film, and paper.

[0327] 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.

[0328] 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.

[0329] 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. .

[0330] The structure shown in this embodiment mode can be used in appropriate combination with other embodiment modes. Cut.

[0331] (Embodiment 2) In this embodiment, an organic compound that can be suitably used in the light-emitting device of one embodiment of the present invention will be described. As an example of a method for synthesizing a compound, the following is taken using the organic compounds represented by the general formulas (G1) and (G2): explain.

[0332] <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.

[0333] 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.

[0334] [ka]

[0335] [ka]

[0336] 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 aromatic ring or condensed aromatic ring represents any one of the trialkylsilyl groups having a number of 3 to 12. Heteroaromatic rings include chrysene, phenanthrene, stilbene, acridone, and phenoxa. In particular, anthracene, pyrene, coumarin, quinacrine, etc. Preferred are benzofuran, perylene, tetracene and naphthobisbenzofuran.

[0337] In the above synthesis schemes (S-1) and (S-2), When performing the Hubbard-Hartwig reaction, 10 ~X 13 is 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.

[0338] 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.

[0339] 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 10 and X 11 It is preferable to carry out the amination reaction selectively using different halogens one by one. I wish.

[0340] 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.

[0341] <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.

[0342] 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 The amine compound (compound 9) is obtained by the condensation reaction of the phosphate compound (compound 8). The scheme (S-3) shows the synthesis of aniline compounds having the same substituents in one step. When two compounds 7) are condensed to introduce amino groups having the same substituent, two equivalents of anion are used. It is preferable to carry out the reaction by adding a phosphorus compound (compound 7). In that case, the cation of compound 8 is The target product can be obtained even if the carbonyl group has no reaction selectivity.

[0343] 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).

[0344] 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).

[0345] 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).

[0346] 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, the amino group of compound 14 may not have reaction selectivity. The target object is obtained.

[0347] 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).

[0348] [ka]

[0349] [ka]

[0350] The second method is shown in the synthetic schemes (S-3) to (S-5), and the following (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, the target compound can be obtained even if the amino group of compound 12 has no reaction selectivity.

[0351] 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).

[0352] 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.

[0353] 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).

[0354] [ka]

[0355] 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.

[0356] In the synthesis schemes (S-7) to (S-10), Y 1 and Y 2 are chlorine, bromine, iodine, Represents a triflate group.

[0357] 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. Examples of inorganic bases that can be used in this reaction include inorganic bases such as sodium hydroxide and sodium hydride. The solvent used is 2,2,6,6-tetramethyl-3,5-heptanedione, 1,3-dimethyl -3,4,5,6-Tetrahydro-2(1H)pyrimidinone (DMPU), toluene, In the Ullmann reaction, the reaction temperature is preferably 100°C or higher. The target product can be obtained in a short time and in high yield, so 2,2,6,6-tetramethylphenyl ether with a high boiling point is preferred. It is preferable to use 3,5-heptanedione, DMPU, and xylene. Since the temperature is more preferably 150°C or higher, it is more preferable to use DMPU. The reagents that can be used in this reaction are not limited to those listed above. do not have.

[0358] 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.

[0359] 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).

[0360] R substituted on the quinacridone skeleton 1 ~R 10 Specific 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 butylsilyl group and a tributylsilyl group.

[0361] 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.

[0362] 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

[0363] (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. 12. The same hatch pattern is used for parts having the same function as the reference numerals shown, and the reference numerals may be omitted. In addition, parts having similar functions are denoted by similar reference numerals, and detailed explanations thereof will be omitted. It may be omitted.

[0364] <Light-emitting device configuration example 2> FIG. 12 is a schematic cross-sectional view of a light-emitting device 250. As shown in FIG.

[0365] The light-emitting device 250 shown in FIG. 12 has a pair of electrodes (electrodes 101 and 102) between them. , and 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. In other words, the light-emitting device 150 shown in FIG. 1A has a single light-emitting element. The light emitting device 250 preferably 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. The following description will be given assuming that the light emitting device 250 functions as a light emitting device. That's fine.

[0366] In addition, in the light-emitting device 250 shown in FIG. The light-emitting units 106 and 108 are stacked, and a charge generating layer is formed between the light-emitting units 106 and 108. The light-emitting unit 106 and the light-emitting unit 108 have the same configuration. For example, the light-emitting unit 108 may have a structure similar to that of the EL layer 100. It is preferable to use it.

[0367] The light emitting device 250 also includes a light emitting layer 160 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.

[0368] Light-emitting device 250 may include any of the layers of light-emitting unit 106 and light-emitting unit 108. It is preferable that the compound according to one embodiment of the present invention is contained in the composition. The layer is preferably the light-emitting layer 160 or the light-emitting layer 170 .

[0369] 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.

[0370] 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.

[0371] 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.

[0372] 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 hole is injected into the other light-emitting unit. For example, in FIG. When a voltage is applied so that the potential of electrode 101 is higher than the potential of electrode 102, a charge is generated. The organic layer 115 injects electrons into the light-emitting unit 106 and holes into the light-emitting unit 108. do.

[0373] 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.

[0374] 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.

[0375] In addition, a light-emitting device having two light-emitting units has been described with reference to FIG. However, the same can be applied to a light-emitting device in which three or more light-emitting units are stacked. 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 with charge generation layers, high brightness light emission is possible while keeping the current density low. This will enable the realization of light-emitting devices with longer life and lower power consumption. It is possible.

[0376] In each of the above configurations, the guest used for the light-emitting unit 106 and the light-emitting unit 108 The light emitting colors of the light emitting materials may be the same or different. A guest material having a function of emitting light of the same color in the light emitting unit 106 and the light emitting unit 108. In this case, the light-emitting device 250 exhibits high light emission luminance at a small current value. In addition, the light-emitting unit 106 and the light-emitting unit 108 may have different colors. When the guest material has the ability to emit light of multiple colors, the light-emitting device 250 can emit multiple colors. In this case, the light-emitting device exhibits a high light-emitting effect. By using multiple luminescent materials with different emission wavelengths for one or both of the The emission spectrum of the device 250 is a composite of light having different emission peaks. This results in an emission spectrum with at least two maxima.

[0377] The above-mentioned configuration is also suitable for obtaining white light emission. By making the colors complementary to each other, white light can be obtained. The guest is then mixed with the guest to produce a white emission, or at least an emission having red, green and blue light. For example, the light-emitting layer 160 may be made of the material shown in the first embodiment. By using the configuration of the light-emitting layers 130a and 130b, green and red light is obtained from the light-emitting layer 160. A configuration in which blue light is emitted from the light-emitting layer 170 is conceivable.

[0378] The light-emitting layer 130a shown in the first embodiment may be used for one or both of the light-emitting layers 160 and 170. It is preferable to use the configuration of the light-emitting layer 130b and the light-emitting layer 130c. In addition, the light-emitting layer 160 is made of the same material as in the first embodiment. When the configuration of the light-emitting layers 130a and 130b shown in FIG. 1 is used, the light-emitting layer 170 becomes a phosphorescent light-emitting layer. The light-emitting layer may be a light-emitting layer, a fluorescent layer, or a light-emitting layer that exhibits both fluorescent and phosphorescent emission. However, a blue fluorescent layer is preferable because white light can be easily obtained if the blue fluorescent layer is used.

[0379] 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 forming the unit into a single layer, the emission intensity of the fluorescent light 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.

[0380] In addition, at least one of the light-emitting layer 160 and the light-emitting layer 170 is further divided into layers, Each divided layer may contain a different light-emitting material. Alternatively, at least one of the light-emitting layers 170 may be composed of two or more layers. For example, the first light-emitting layer and the second light-emitting layer can be laminated in this order from the hole transport layer side to form the light-emitting layer. In this case, a material having 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 the function of emitting light of the same color, it may have the function of emitting light of different colors. A plurality of light-emitting materials each having a function of emitting light of a different color may be used. By using this configuration, it is possible to obtain white light with high color rendering properties consisting of the three primary colors or four or more colors. It is also possible.

[0381] The phosphorescent layer described in the third embodiment includes the hole transporting material and the electron transporting material described in the first embodiment. The transport material and the phosphorescent material can be used in appropriate combination.

[0382] The host material and guest material used in the blue fluorescent-emitting layer described in the third embodiment are Although there is no particular limitation, the following materials can be mentioned.

[0383] As the guest material, for example, a pyrene derivative, a perylene derivative, etc. can be used. For example, the following materials can be used:

[0384] Specifically, N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-phenyl) Fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPr n), N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl- 9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mM emFLPAPrn), N,N'-bis[4-(9-phenyl-9H-fluorene-9- -N,N'-bis(4-tert-butylphenyl)-pyrene-1,6 -diamine (abbreviation: 1,6tBu-FLPAPrn), N,N'-bis[4-(9-phenyl N,N'-diphenyl-3,8-diphenyl Cyclohexylpyrene-1,6-diamine (abbreviation: ch-1,6FLPAPrn), 5,1 0,15,20-Tetraphenylbisbenzo[5,6]indeno[1,2,3-cd:1 ',2',3'-lm]perylene (abbreviation: DBP).

[0385] Examples of the host material include anthracene derivatives, phenanthrene derivatives, and pyrene derivatives. condensed polycyclic aromatic compounds such as chrysene derivatives, dibenzo[g,p]chrysene derivatives, etc. Specifically, tris(8-quinolinolato)aluminum(III) (abbreviation: A lq), tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Al mq3), bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation :BeBq2), Bis(2-methyl-8-quinolinolato)(4-phenylphenolato)a Aluminum(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq), bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation :ZnPBO), bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation Metal complexes such as ZnBTZ, 2-(4-biphenylyl)-5-(4-tert-butyl) phenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-( p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 3-(4-biphenylyl)-4-phenyl-5-(4-tert -butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 2,2',2''- (1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), bathophenanthroline (abbreviation: BPhen), bathocuproine ( Abbreviation: BCP), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl )phenyl]-9H-carbazole (abbreviation: CO11) and other heterocyclic compounds, Bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB or α -NPD), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1 '-biphenyl]-4,4'-diamine (abbreviation: TPD), 4,4'-bis[N-(spi 1,2-Dimethyl-9,9'-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: B Aromatic amine compounds such as SPB are also included. Thylene derivatives, pyrene derivatives, chrysene derivatives, dibenzo[g,p]chrysene derivatives, etc. Condensed polycyclic aromatic compounds are exemplified, specifically, 9,10-diphenylanthracene (abbreviation Name: DPAnth), N,N-diphenyl-9-[4-(10-phenyl-9-anthri 4-(10-phenyl)phenyl]-9H-carbazol-3-amine (abbreviation: CzA1PA), -phenyl-9-anthryl)triphenylamine (abbreviation: DPhPA), 4-(9H- Carbazol-9-yl)-4'-(10-phenyl-9-anthryl)triphenyl amine (abbreviation: YGAPA), N,9-diphenyl-N-[4-(10-phenyl-9-phenyl) N,9H-carbazol-3-amine (abbreviation: PCAPA) -Diphenyl-N-{4-[4-(10-phenyl-9-anthryl)phenyl]phenyl N,9-diphenyl- N-(9,10-diphenyl-2-anthryl)-9H-carbazol-3-amine (abbreviation Name: 2PCAPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H -Dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 6,12-dimethoxy -5,11-diphenylchrysene, N,N,N',N',N'',N'',N''',N '''-Octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetraamine DBC1, 9-phenyl-3-[4-(10-phenyl-9-anthryl) phenyl]-9H-carbazole (abbreviation: PCzPA), 3,6-diphenyl-9-[4 -(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: DPC zPA), 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPP A), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 2-tert-bu 9,9' t-BuDNA, 9,10-di(2-naphthyl)anthracene -Bianthryl (abbreviation: BANT), 9,9'-(stilbene-3,3'-diyl)diphenyl Phenanthrene (abbreviation: DPNS), 9,9'-(stilbene-4,4'-diyl)diphenyl Nanthrene (abbreviation: DPNS2), 1,3,5-tri(1-pyrenyl)benzene (abbreviation: Among these and other known substances, the above-mentioned Guess A material that has an energy gap larger than the energy gap of the target material is called a A plurality of types may be selected and used.

[0386] Note that this embodiment mode can be appropriately combined with other embodiment modes.

[0387] (Embodiment 4) In this embodiment, a light emitting device using the light emitting device described in the first and third embodiments is The arrangement will be described with reference to FIGS. 13A and 13B.

[0388] FIG. 13A is a top view showing a light-emitting device, and FIG. 13B is a cross-sectional view of FIG. 13A cut along lines AB and CD. This light emitting device is shown by the dotted line as a device for controlling the light emission of a light emitting device. A driving circuit section (source side driving circuit) 601, a pixel section 602, a driving circuit section (gate side driving circuit) The device includes a sealing substrate 604, a desiccant 625, and a seal 605. The inside surrounded by the sealing material 605 forms a space 607 .

[0389] 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 an FPC or This includes the state where the PWB is installed.

[0390] Next, the cross-sectional structure of the light emitting device will be described with reference to FIG. A driving circuit section and a pixel section are formed. Here, the source side driving circuit, which is the driving circuit section, is A path 601 and one pixel in a pixel section 602 are shown.

[0391] 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. This shows a driver integrated type with a driver circuit formed on the board, but this is not necessarily required. Alternatively, it may be formed externally.

[0392] 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.

[0393] 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.

[0394] 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.

[0395] 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).

[0396] 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. In the case where the generated light is transmitted through the second electrode 617, a thin film is used as the second electrode 617. A thin metal film and a transparent conductive film (ITO, containing 2wt% to 20wt% zinc oxide) Indium oxide, silicon-containing indium tin oxide, zinc oxide (ZnO, etc.) It is better to use layers.

[0397] 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.

[0398] Furthermore, the sealing substrate 604 is bonded to the element substrate 610 with a sealant 605, A light emitting device is placed in a space 607 surrounded by a child substrate 610, a sealing substrate 604, and a sealant 605. The structure is provided with a chair 618. The space 607 is filled with a filling material. In addition to cases where inert gas (nitrogen, argon, etc.) is filled, resin, desiccant, or Sometimes it is filled with both.

[0399] 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.

[0400] As described above, the light emitting devices described in the first and third embodiments are used to emit light. The device can be obtained.

[0401] <Light-emitting device configuration example 1> FIG. 14 shows an example of a display device in which a light-emitting device that emits white light is formed, and a colored layer ( An example of a light emitting device having a transparent filter is shown.

[0402] FIG. 14A shows a substrate 1001, an insulating base film 1002, a gate insulating film 1003, and a gate electrode 1004. 006, 1007, 1008, a first interlayer insulating film 1020, a second interlayer insulating film 1021, A peripheral section 1042, a pixel section 1040, a driving circuit section 1041, a first electrode 10 of a light emitting device 24W, 1024R, 1024G, 1024B, partition 1025, EL layer 1028, light-emitting device A second electrode 1029 of the semiconductor device, a sealing substrate 1031, a sealant 1032, and a red pixel 1044. R, green pixel 1044G, blue pixel 1044B, white pixel 1044W, etc. are shown. do.

[0403] 14A and 14B show colored layers (a red colored layer 1034R, a green colored layer 1034 G, a blue colored layer 1034B is provided on a transparent substrate 1033. A transparent matrix 1035 having a colored layer and a black layer may be provided. The base material 1033 is aligned and fixed to the substrate 1001. The colored layer and the black layer are 14A, the colored layer is covered with an overcoat layer 1036. There are light-emitting layers that emit light to the outside without being transmitted, and light-emitting layers that transmit light through the colored layers of each color and emit light to the outside. The light that does not pass through the colored layer is white, and the light that does pass through the colored layer is red, blue, and green, so there are four colors. An image can be expressed using only 100 pixels.

[0404] In FIG. 14B, a red colored layer 1034R, a green colored layer 1034G, and a blue colored layer 1034 In this example, B is formed between the gate insulating film 1003 and the first interlayer insulating film 1020. As shown in FIG. 14B, the colored layer may be provided between the substrate 1001 and the sealing substrate 1031.

[0405] 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 taken in from the sealing substrate 1031 side. The light emitting device may have a top emission structure.

[0406] <Configuration Example 2 of Light Emitting Device> Cross-sectional views of a top-emission type light-emitting device are shown in Figures 15A and 15B. The plate 1001 can be a light-opaque substrate. The process is the same as that of a bottom emission type light emitting device until the connection electrodes are formed. Thereafter, a third interlayer insulating film 1037 is formed to cover the electrode 1022. The third interlayer insulating film 1037 may have a flattening effect. In addition to the materials similar to those mentioned above, various other materials can be used to form the insulating film.

[0407] 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 15B, the lower electrode 1025W, The electrode 1025R, the lower electrode 1025G, and the lower electrode 1025B are preferably reflective electrodes. It is preferable that the second electrode 1029 has a function of reflecting light and a function of transmitting light. In addition, the second electrode 1029, the lower electrode 1025W, the lower electrode 1025R, A microcavity structure is applied between the top electrode 1025G and the bottom electrode 1025B to generate a specific wavelength. It is preferable that the EL layer 1028 has a function of amplifying light. The device has a configuration as explained in the third embodiment, and has an element structure capable of emitting white light.

[0408] 14A, 14B, 15A, and 15B, the EL layer structure from which white light is obtained is shown. The structure is realized by using multiple light-emitting layers or multiple light-emitting units. However, the configuration for obtaining white light emission is not limited to these.

[0409] In the top emission structure as shown in FIG. 15A and FIG. 15B, the colored layer (red colored layer 103) 4R, a green colored layer 1034G, and a blue colored layer 1034B) are provided on the sealing substrate 1031. The sealing substrate 1031 is provided with black insulating film 1032 disposed between the pixels. A layer (black matrix) 1030 may be provided. A color layer (red color layer 1034R , green colored layer 1034G, blue colored layer 1034B) and black layer (black matrix The sealing substrate 1031 may be covered with an overcoat layer. A substrate is used.

[0410] In addition, while FIG. 15A shows a configuration for full-color display using three colors, red, green, and blue, FIG. As shown in FIG. 1, a full-color display may be performed using four colors: red, green, blue, and white. The color display configuration is not limited to these. For example, a four-color display with red, green, blue, and yellow may be used. A full color display may be performed.

[0411] 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.

[0412] As described above, the light emitting devices described in the first and third embodiments are used to emit light. The device can be obtained.

[0413] Note that this embodiment mode can be appropriately combined with other embodiment modes.

[0414] (Embodiment 5) In this embodiment, an electronic device and a display device according to one embodiment of the present invention will be described.

[0415] 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.

[0416] Examples of electronic devices include television sets, desktop or notebook PCs, etc. Computers, monitors for computers, digital cameras, digital video cameras Cameras, digital photo frames, mobile phones, portable game consoles, personal digital assistants, audio playback Examples of such devices include large gaming machines such as pachinko machines.

[0417] A mobile information terminal 900 shown in FIG. 16A and FIG. 16B includes a housing 901, a housing 902, a display unit 90 3, and a hinge portion 905.

[0418] 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. 16A), it can be unfolded as shown in FIG. 16B. This makes it easy to carry around, and the large display area makes it easy to see when in use. Excellent in.

[0419] 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.

[0420] 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.

[0421] 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.

[0422] When the portable information terminal 900 is unfolded, the display unit 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.

[0423] The display unit 903 functions as a touch panel and can be operated by a finger, a stylus, etc. can.

[0424] 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.

[0425] 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.

[0426] 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.

[0427] 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.

[0428] 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.

[0429] A portable information terminal 910 shown in FIG. 16C 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.

[0430] 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.

[0431] 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.

[0432] 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.

[0433] 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.

[0434] 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.

[0435] The camera 920 shown in FIG. 16D 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.

[0436] The 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.

[0437] 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.

[0438] 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

[0439] The camera 920 can be equipped with a strobe device, viewfinder, etc. Alternatively, these may be incorporated into the housing 921.

[0440] FIG. 17A is a schematic diagram showing an example of a cleaning robot.

[0441] 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.

[0442] 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.

[0443] 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.

[0444] 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.

[0445] 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.

[0446] The light-emitting device according to one embodiment of the present invention can be used for the display 5101 .

[0447] The robot 2100 shown in FIG. 17B 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.

[0448] 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.

[0449] 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.

[0450] 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.

[0451] The light-emitting device according to one embodiment of the present invention can be used for the display 2105 .

[0452] FIG. 17C 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.

[0453] The light-emitting device of one embodiment of the present invention can be used for the display portion 5001 and the second display portion 5002. can.

[0454] 18A and 18B 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. 18A shows a portable information terminal 5150 in an unfolded state. FIG. 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.

[0455] 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.

[0456] 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 can be used in the display region 5152. Cut.

[0457] This embodiment mode can be combined with other embodiment modes as appropriate.

[0458] (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. 19. 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.

[0459] 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.

[0460] 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.

[0461] FIG. 19 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.

[0462] 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.

[0463] 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 lighting devices and electronic devices in all fields, not limited to the above.

[0464] The structure described in this embodiment may be used in appropriate combination with structures described in other embodiments. There can be. [Explanation of symbols]

[0465] 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: separation layer, 130a: light emitting layer, 130b: light emitting layer, 131: Compound, 131_f: Compound, 132: Compound, 132_f: Compound, 133: compound, 134: compound, 135: compound, 135_p: compound, 135_1: compound, 135_1p: compound, 135_2: compound, 135_2p: compound, 136: compound, 136_p: compound, 150: light-emitting device, 152: light-emitting device, 160: light-emitting layer, 170: Light-emitting layer, 200: EL layer, 250: Light-emitting device, 301: Guest material, 302 : guest material, 310: luminophore, 320: protecting group, 330: host material, 601: source 602: pixel section; 603: gate side driving circuit; 604: sealing substrate; 605: Sealing material, 607: space, 608: wiring, 609: FPC, 610: element substrate, 611: Switching TFT, 612: Current control TFT, 613: Electrode, 614: Insulator, 6 16: EL layer, 617: electrode, 618: light-emitting device, 623: n-channel TFT, 6 24: p-channel TFT, 625: desiccant, 900: mobile information terminal, 901: housing, 9 02: Housing, 903: Display unit, 905: Hinge unit, 910: Portable information terminal, 911: Housing 912: display unit, 913: operation buttons, 914: external connection port, 915: speaker, 916: microphone, 917: camera, 920: camera, 921: housing, 922: display unit, 9 23: Operation button, 924: Shutter button, 926: Lens, 1001: Board, 10 02: Undercoat insulating film, 1003: Gate insulating film, 1006: Gate electrode, 1007: Gate Electrode, 1008: gate electrode, 1020: interlayer insulating film, 1021: interlayer insulating film, 1022 :electrode, 1024B:electrode, 1024G:electrode, 1024R:electrode, 1024W:electrode, 1025B: Bottom electrode, 1025G: Bottom electrode, 1025R: Bottom electrode, 1025W: Bottom Part electrode, 1025: Partition wall, 1028: EL layer, 1029: Electrode, 1031: Sealing substrate, 1 032: sealing material, 1033: base material, 1034B: colored layer, 1034G: colored layer, 103 4R: colored layer, 1036: overcoat layer, 1037: interlayer insulating film, 1040: pixel portion 1041: driving circuit section, 1042: peripheral section, 1044R: red pixel, 1044G: green pixel Pixel, 1044B: Blue pixel, 1044W: White pixel, 2100: Robot, 2101: Illuminance sensor, 2102: microphone, 2103: upper camera, 2104: speaker, 2105: display, 2106: lower camera, 2107: obstacle sensor, 2108: Moving mechanism, 2110: arithmetic unit, 5000: housing, 5001: display unit, 5002: display unit , 5003: Speaker, 5004: LED lamp, 5006: Connection terminal, 5007: Sensor 5008: microphone, 5012: support, 5013: earphone, 5100: sweeper Robot, 5101: Display, 5102: Camera, 5103: Brush, 5104 : Operation button, 5120: Garbage, 5140: Portable electronic device, 5150: Portable information terminal, 5 151: Housing, 5152: Display area, 5153: Bending portion, 8501: Illumination device, 8502 : Lighting equipment, 8503: Lighting equipment, 8504: Lighting equipment

Claims

1. A first light-emitting layer and a second light-emitting layer are disposed between a pair of electrodes, the first light-emitting layer comprises a first material and a second material; the first material has a function of converting triplet excitation energy into luminescence, the second material has a function 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, and a trialkylsilyl group having from 3 to 12 carbon atoms; Light emission is obtained from the second material; the second light-emitting layer comprising a third material that is a thermally activated delayed fluorescent material and a fourth material that comprises a platinum group element.

2. In claim 1, a light-emitting device, wherein at least four of the five or more protecting groups are each independently 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 first light-emitting layer and a second light-emitting layer are disposed between a pair of electrodes, the first light-emitting layer comprises a first material and a second material; the first material has a function of converting triplet excitation energy into luminescence, the second material has a function 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 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; Light emission is obtained from the second material; the second light-emitting layer comprising a third material that is a thermally activated delayed fluorescent material and a fourth material that comprises a platinum group element.

4. A first light-emitting layer and a second light-emitting layer are disposed between a pair of electrodes, the first light-emitting layer comprises a first material and a second material; the first material has a function of converting triplet excitation energy into luminescence, the second material has a function 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 has 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; Light emission is obtained from the second material; the second light-emitting layer comprising a third material that is a thermally activated delayed fluorescent material and a fourth material that comprises a platinum group element.

5. A first light-emitting layer and a second light-emitting layer are disposed between a pair of electrodes, the first light-emitting layer comprises a first material and a second material; the first material has a function of converting triplet excitation energy into luminescence, the second material has a function 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 has 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; Light emission is obtained from the second material; the second light-emitting layer comprising a third material that is a thermally activated delayed fluorescent material and a fourth material that comprises a platinum group element.

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

7. A first light-emitting layer and a second light-emitting layer are disposed between a pair of electrodes, the first light-emitting layer comprises a first material and a second material; the first material has a function of converting triplet excitation energy into luminescence, the second material has a function 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 plurality of protecting groups each independently have one of an alkyl group having from 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having from 3 to 10 carbon atoms, 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; Light emission is obtained from the second material; The second light-emitting layer comprises a third material that is a thermally activated delayed fluorescent material and a fourth material that comprises a platinum group element.

8. A first light-emitting layer and a second light-emitting layer are disposed between a pair of electrodes, the first light-emitting layer comprises a first material and a second material; the first material has a function of converting triplet excitation energy into luminescence, the second material has a function 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 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; Light emission is obtained from the second material; the second light-emitting layer comprising a third material that is a thermally activated delayed fluorescent material and a fourth material that comprises a platinum group element.

9. In any one of claims 1 to 8, The light-emitting device, wherein the protecting group is an alkyl group.

10. In any one of claims 1 to 9, The light emitting device wherein the alkyl group is a branched chain alkyl group.

11. In claim 10, A light emitting device, wherein the branched alkyl group has a quaternary carbon.

12. In any one of claims 1 to 11, A light-emitting device, wherein 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.

13. In any one of claims 1 to 12, the first light-emitting layer further comprising a sixth material; A light-emitting device, wherein the first material and the sixth material are in a combination that forms a first exciplex.

14. In claim 13, An emission spectrum of the first exciplex overlaps with an absorption spectrum of the second material.

15. In any one of claims 1 to 14, The first material is a first phosphorescent material.

16. In any one of claims 1 to 14, A light-emitting device, wherein the first material is a compound that exhibits thermally activated delayed fluorescence.

17. In any one of claims 1 to 16, The platinum group element is any one of ruthenium, rhodium, palladium, osmium, iridium, and platinum.

18. In any one of claims 1 to 17, A light-emitting device, wherein the first light-emitting layer and the second light-emitting layer have different emission colors.

19. In any one of claims 1 to 17, A light emitting device, wherein the emission color of the second material is different from the emission color of the fourth material.

20. In any one of claims 1 to 17, a peak wavelength of an emission spectrum obtained from the first light-emitting layer is shorter than a peak wavelength of an emission spectrum obtained from the second light-emitting layer.

21. In any one of claims 1 to 17, A light emitting device, wherein the peak wavelength of the emission spectrum of the second material is shorter than the peak wavelength of the emission spectrum of the fourth material.

22. A light emitting device according to any one of claims 1 to 21; At least one of a housing or a touch sensor; An electronic device having the

23. A light emitting device according to any one of claims 1 to 21; At least one of a housing or a touch sensor; A lighting device having the above structure.

Images