Metal-organic complex, light-emitting device, light-emitting apparatus, electronic device and lighting device

Abstract

A novel organometallic complex for improving the emission efficiency of a light-emitting device is provided. An organometallic complex represented by the general formula (G1) is provided. In the formula, X represents carbon or nitrogen, and the carbon is bonded to hydrogen (including deuterium), a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, or a substituted or unsubstituted aryl group. Furthermore, R1 to R3 each independently represent hydrogen (including deuterium), a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, or a substituted or unsubstituted aryl group. Additionally, n represents an integer greater than or equal to 1 and less than or equal to 4.The borate ligands can be the same or different. Furthermore, the respective n can be the same or different. In the case where n is two or more, the respective X, R1, and R2 can be the same or different. In the case where n is two or less, the respective R3 can be the same or different.

Description

Organometallic complex, light-emitting device, light-emitting apparatus, electronic device and lighting apparatus

[0001] One embodiment of the present invention relates to an organometallic complex, an organic compound, an organic semiconductor element, a light-emitting device, a light-emitting element, an organic EL element, an organic EL element, a photodiode sensor, a light-receiving device, a light-receiving element, a display module, a lighting module, a display device, a light-emitting device, an electronic device, a lighting device, and an electronic device. Note that one embodiment of the present invention is not limited to the above technical field. The technical field of one embodiment of the invention disclosed in this specification etc. relates to an object, a method, or a manufacturing method. Alternatively, one embodiment of the present invention relates to a process, a machine, manufacture, or a composition of matter. Therefore, more specifically, examples of the technical field of one embodiment of the present invention disclosed in this specification include a semiconductor device, a display device, a liquid crystal display device, a light-emitting device, a lighting device, a power storage device, a memory device, an imaging device, a driving method thereof, or a manufacturing method thereof.

[0002] Light-emitting devices (also called light-emitting elements or organic EL elements) that utilize electroluminescence (EL) using organic compounds are becoming increasingly practical. The basic structure of these light-emitting devices is a pair of electrodes sandwiching an organic compound layer (EL layer) containing a light-emitting material between them. By applying a voltage to this device, carriers are injected, and the recombination energy of the carriers is utilized to emit light from the light-emitting material.

[0003] Since organic EL elements are self-luminous, displays using these elements as pixels have higher visibility than liquid crystal displays and do not require backlighting. Another major advantage of such displays using organic EL elements is that they can be fabricated to be thin and lightweight. Another feature is their extremely fast response speed.

[0004] Furthermore, these organic EL elements can have a light-emitting layer continuously formed in a planar shape, thereby enabling planar light emission, which is a feature that is difficult to obtain with point light sources such as incandescent lamps and LEDs, or linear light sources such as fluorescent lamps, making them highly useful as planar light sources for lighting and other applications.

[0005] Thus, display devices and lighting devices using organic EL elements are suitable for a variety of electronic devices, but research and development is ongoing in search of organic EL elements with even better characteristics.

[0006] For example, Non-Patent Document 1 reports on an organic EL device using a lanthanoid complex as a new light-emitting dopant.

[0007] Liding Wang, 6 others, “Review on the Electroluminescence Study of Lanthanide Complexes”, Advanced Optical Materials, 2019, 7, 1801256

[0008] As described in Non-Patent Document 1, there are very few cases in which the application of these organic complexes as luminescent materials (also called dopants) in organic EL devices has been investigated, and sufficient investigation has not yet been carried out. Therefore, there is a great deal of room for improvement in the performance of these organic complexes related to display quality, such as chromaticity or color purity, and further development is awaited.

[0009] Thus, one embodiment of the present invention provides a novel organometallic complex. Another embodiment of the present invention provides a novel organometallic complex that can be used in a light-emitting device. Another embodiment of the present invention provides a novel organometallic complex that can be used in an EL layer of a light-emitting device. Another embodiment of the present invention aims to improve the emission efficiency of a light-emitting device. Another embodiment of the present invention aims to improve the reliability of a light-emitting device. Another embodiment of the present invention provides a novel light-emitting device.

[0010] Another object of one embodiment of the present invention is to provide a light-emitting device with high emission efficiency, or a light-emitting device, an electronic device, a display device, and an electronic device with low power consumption.

[0011] Note that the description of these problems does not preclude the existence of other problems. Note that one embodiment of the present invention does not necessarily need to solve all of these problems. Note that problems other than these will become apparent from the description in the specification, drawings, claims, etc., and it is possible to extract other problems from the description in the specification, drawings, claims, etc.

[0012] One embodiment of the present invention is an organometallic complex represented by General Formula (G1).

[0013]

[0014] In general formula (G1), X represents carbon or nitrogen, and the carbon is bonded to any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. １ ~R ３ each independently represents one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. n represents an integer of 1 to 4. The borate ligands may be the same or different from each other. The n of each borate ligand may be the same or different from each other. When n is 2 or more, the X of each borate ligand may be the same or different from each other, and the R of each borate ligand may be the same or different from each other. １ may be the same or different, and R of each borate ligand ２ may be the same or different. When n is 2 or less, R ３ may be the same or different from each other.

[0015] Another embodiment of the present invention is an organometallic complex represented by General Formula (G2).

[0016]

[0017] In general formula (G2), R １ ~R ３ each independently represents one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. n represents an integer of 1 to 4. The borate ligands may be the same or different from each other. The n of each borate ligand may be the same or different from each other. When n is 2 or more, the X of each borate ligand may be the same or different from each other, and the R of each borate ligand may be the same or different from each other. １ may be the same or different, and R of each borate ligand ２ may be the same or different. When n is 2 or less, R ３ may be the same or different from each other.

[0018] Another embodiment of the present invention is an organometallic complex represented by General Formula (G3).

[0019]

[0020] In general formula (G3), X １ ~X ３ each independently represents carbon or nitrogen, and the carbon is bonded to any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. １１ ~R １３ , R ２１ ~R ２３ and R ３１ ~R ３３Each of j, k, and p independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. In addition, j, k, and p each independently represent an integer of 1 to 4. When j is 2 or more, each of X １ may be the same or different, and each R １１ may be the same or different, and each R １２ may be the same or different. When k is 2 or more, each X ２ may be the same or different, and each R ２１ may be the same or different, and each R ２２ may be the same or different. When p is 2 or more, each X ３ may be the same or different, and each R ３１ may be the same or different, and each R ３２ may be the same or different. When j is 2 or less, each R １３ may be the same or different. When k is 2 or less, each R ２３ may be the same or different. When p is 2 or less, each R ３３ may be the same or different from each other.

[0021] Another embodiment of the present invention is an organometallic complex represented by a general formula (G3′).

[0022]

[0023] In general formula (G3'), X １ ~X ３each independently represents carbon or nitrogen, and the carbon is bonded to any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. １１ ~R １３ , R ２１ ~R ２３ and R ３１ ~R ３３ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. j represents an integer of 1 to 3. k and p each independently represent an integer of 1 to 4. When j is 2 or more, each X １ may be the same or different, and each R １１ may be the same or different, and each R １２ may be the same or different. When k is 2 or more, each X ２ may be the same or different, and each R ２１ may be the same or different, and each R ２２ may be the same or different. When p is 2 or more, each X ３ may be the same or different, and each R ３１ may be the same or different, and each R ３２ may be the same or different. When j is 2 or less, each R １３ may be the same or different. When k is 2 or less, each R ２３ may be the same or different. When p is 2 or less, each R ３３ may be the same or different from each other.

[0024] Another embodiment of the present invention is an organometallic complex represented by General Formula (G4).

[0025]

[0026] In general formula (G4), X ２ and X ３ each independently represents carbon or nitrogen, and the carbon is bonded to any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. １１ ~R １３ , R ２１ ~R ２３ and R ３１ ~R ３３ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. j, k, and p each independently represent an integer of 1 to 4. When j is 2 or more, each R １１ may be the same or different, and each R １２ may be the same or different. When k is 2 or more, each X ２ may be the same or different, and each R ２１ may be the same or different, and each R ２２ may be the same or different. When p is 2 or more, each X ３ may be the same or different, and each R ３１ may be the same or different, and each R ３２ may be the same or different. When j is 2 or less, each R １３ may be the same or different. When k is 2 or less, each R ２３ may be the same or different. When p is 2 or less, each R３３ may be the same or different from each other.

[0027] Another embodiment of the present invention is an organometallic complex represented by General Formula (G5).

[0028]

[0029] In general formula (G5), X １１ ~X １３ , X ２１ ~X ２３ , X ３１ and X ３２ each independently represents carbon or nitrogen, and the carbon is bonded to any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. ４１ ~R ４７ , R ５１ ~R ５７ and R ６１ ~R ６６ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms.

[0030] Another embodiment of the present invention is an organometallic complex represented by structural formulas (125) and (150).

[0031]

[0032] Another embodiment of the present invention is a light-emitting device using any of the organic compounds having any of the above structures.

[0033] Another embodiment of the present invention is a light-emitting device including the light-emitting device having any of the above structures and a transistor or a substrate.

[0034] Another embodiment of the present invention is an electronic device including a light-emitting device having any of the above structures and a detection unit, an input unit, or a communication unit.

[0035] Another embodiment of the present invention is a lighting device including a light-emitting device having any of the above structures and a housing.

[0036] In this specification, the term "light-emitting device" includes an image display device using a light-emitting device. The term "light-emitting device" may also include a module in which a connector, such as an anisotropic conductive film or a TCP (Tape Carrier Package), is attached to a light-emitting device on a substrate, a module in which a printed wiring board is provided at the end of the TCP, or a module in which an IC (integrated circuit) is directly mounted on a light-emitting device using a COG (Chip On Glass) method. Furthermore, lighting fixtures and the like may have a light-emitting device.

[0037] According to one embodiment of the present invention, a novel organometallic complex can be provided. According to another embodiment of the present invention, a novel organometallic complex that can be used in a light-emitting device can be provided. According to another embodiment of the present invention, a novel organometallic complex that can be used in an EL layer of a light-emitting device can be provided. According to another embodiment of the present invention, the light-emitting efficiency of a light-emitting device can be improved. According to another embodiment of the present invention, the reliability of a light-emitting device can be improved. According to another embodiment of the present invention, a novel light-emitting device can be provided.

[0038] According to one embodiment of the present invention, a light-emitting device with high emission efficiency can be provided. Alternatively, according to one embodiment of the present invention, a light-emitting device, a light-emitting apparatus, an electronic device, a display device, and an electronic device with low power consumption can be provided.

[0039] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. Note that effects other than these will become apparent from the description in the specification, drawings, claims, etc., and it is possible to extract other effects from the description in the specification, drawings, claims, etc.

[0040] FIGS. 1A to 1E are diagrams illustrating a configuration of a light-emitting device according to an embodiment. FIGS. 2A to 2D are diagrams illustrating a light-emitting device according to an embodiment. FIGS. 3A to 3C are diagrams illustrating a manufacturing method of a light-emitting device according to an embodiment. FIGS. 4A to 4C are diagrams illustrating a manufacturing method of a light-emitting device according to an embodiment. FIGS. 5A to 5C are diagrams illustrating a manufacturing method of a light-emitting device according to an embodiment. FIGS. 6A to 6D are diagrams illustrating a manufacturing method of a light-emitting device according to an embodiment. FIGS. 7A to 7D are diagrams illustrating a light-emitting device according to an embodiment. FIGS. 8A to 8C are diagrams illustrating a light-emitting device according to an embodiment. FIGS. 9A to 9F are diagrams illustrating a device and pixel arrangement according to an embodiment. FIGS. 10A to 10C are diagrams illustrating a pixel circuit according to an embodiment. FIG. 11 is a diagram illustrating a light-emitting device according to an embodiment. FIGS. 12A to 12E are diagrams illustrating an electronic device according to an embodiment. FIGS. 13A to 13E are diagrams illustrating an electronic device according to an embodiment. FIGS. 14A and 14B are diagrams illustrating an electronic device according to an embodiment. 15A and 15B are diagrams illustrating an illumination device according to an embodiment. FIG. 16 is a diagram illustrating an illumination device according to an embodiment. FIGS. 17A to 17C are diagrams illustrating a light-emitting device and a light-receiving device according to an embodiment. FIGS. 18A and 18B are diagrams illustrating a light-emitting device and a light-receiving device according to an embodiment. FIG. 19 is a diagram illustrating a [Ce(bpz ３ ) ２ (bpz ２ ) in dichloromethane. ３ ) ２ (btaz ２ ) in dichloromethane. ３ ) ２ (btaz ２) ] powder. Figure 22 is a diagram illustrating the configuration of light-emitting device 1. Figure 23 is a diagram illustrating the luminance-current density characteristics of light-emitting device 1. Figure 24 is a diagram illustrating the current efficiency-luminance characteristics of light-emitting device 1. Figure 25 is a diagram illustrating the luminance-voltage characteristics of light-emitting device 1. Figure 26 is a diagram illustrating the current-voltage characteristics of light-emitting device 1. Figure 27 is a diagram illustrating the external quantum efficiency-luminance characteristics of light-emitting device 1. Figure 28 is a diagram illustrating the emission spectrum of light-emitting device 1.

[0041] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be readily understood by those skilled in the art that various changes in form and details can be made without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the embodiments shown below.

[0042] First Embodiment Displays using organic EL elements as display elements (organic EL displays) have been in practical use for a long time. In order to achieve full-color display, such displays typically include pixels that emit light of at least three colors: red, green, and blue.

[0043] A light-emitting device is provided for each pixel for each emitted color, and in a side-by-side type display, or a so-called color-coded type display, each light-emitting device has a different light-emitting material according to the emitted color of the corresponding pixel.

[0044] As light-emitting materials used in such light-emitting devices, fluorescent materials that emit light from a singlet excited state, materials that emit thermally activated delayed fluorescence (TADF), phosphorescent materials that emit light from a triplet excited state, and the like are mainly used and are being actively researched.

[0045] In current-excited organic EL devices, the ratio of the generation probability of the singlet excited state to the triplet excited state is 1:3, and therefore, the theoretical limit of the internal quantum efficiency of fluorescent materials that can only emit light in the singlet excited state is known to be 25%. On the other hand, phosphorescent materials can convert the singlet excited state to the triplet excited state through intersystem crossing, so that an internal quantum efficiency of 100% can be theoretically achieved, enabling light-emitting devices with high luminous efficiency to be obtained. For this reason, phosphorescent materials are often used in the red and green light-emitting devices of organic EL displays currently in practical use.

[0046] However, even in displays that use phosphorescent materials in the red and green light-emitting devices, the blue light-emitting device almost always uses a less efficient fluorescent material rather than a phosphorescent material. The reason for using fluorescent materials in blue light-emitting devices is primarily due to reliability, not efficiency. Light-emitting devices that use phosphorescent materials as dopants generally have short lifetimes and are difficult to achieve good reliability. For this reason, almost all blue light-emitting devices currently used in commercially available organic electroluminescence (EL) displays are fluorescent devices. If the lifetime issue could be resolved, the performance of OLED displays could be significantly improved by applying blue phosphorescent materials with excellent luminous efficiency to blue light-emitting devices. However, there are two fundamental reasons for the short lifetime of blue phosphorescent devices.

[0047] The first reason is that in ordinary materials, the energy of the triplet state is lower than that of the singlet state. Because blue light emission has high energy, a material with a triplet excitation level higher than those of the other two colors is required to obtain light emission from the triplet excited state. Naturally, the singlet excitation level of such a material is located at an even higher position, and a material with such a level is likely to be unstable. Furthermore, when a host material is used, the host material needs to be a material with triplet and singlet excitation levels located at even higher energy levels.

[0048] The second factor is the long luminescence lifetime (also called phosphorescence lifetime) of phosphorescent materials. Because the transition from the triplet excited state to the singlet ground state is spin-forbidden, while the transition from the singlet regular state to the singlet ground state is spin-allowed, phosphorescence has a much longer luminescence lifetime than fluorescence (phosphorescence lifetime: ~μs, fluorescence lifetime: ~ns). A long phosphorescence lifetime means a long lifetime of triplet excitons. Therefore, in phosphorescent light-emitting devices, the luminescent material remains in a high-energy excited state for a long time, which accelerates the degradation of the luminescent material itself and surrounding materials.

[0049] In blue phosphorescent devices, the energy of the top excited state is higher than that of the other two colors, so the impact of the exciton lifetime is even more pronounced than in red and green phosphorescent devices, and it is still difficult to achieve reliability sufficient for practical use.

[0050] The TADF material mentioned above is a type of fluorescent material because it emits light from a singlet excited state, but it is capable of reverse intersystem crossing. This makes it possible to convert triplet excitation energy into singlet excitation energy, theoretically achieving an internal quantum efficiency of 100%, similar to phosphorescent materials. Therefore, light-emitting devices using TADF materials as dopants and light-emitting devices using TADF materials as hosts and fluorescent materials as dopants have been proposed, and both have shown internal quantum efficiencies exceeding 25%. However, TADF materials, like phosphorescent materials, have the problem of triplet excitation levels. Furthermore, because reverse intersystem crossing is prohibited, the exciton lifetime is long, making it difficult to ensure reliability, similar to blue phosphorescent devices.

[0051] Here, Ce emits light through the f-d transition, which is a transition between the f orbital and the d orbital. ３＋ (4 ｆ１ ) and Eu ２＋ (4 ｆ７) organic complexes are known. Both the ground state and excited state of these organic complexes are doublet states, and light is emitted from the doublet excited state. As mentioned above, in the case of current excitation, singlet excited levels and triplet excited levels are generated from the singlet ground state in a ratio of 1:3. However, since the ground state and excited state of these organic complexes are both doublet states, the doublet excited state is theoretically generated 100% without being restricted by the spin selection rule, and an internal quantum efficiency of 100% is possible.

[0052] Although the transition between different orbitals may be parity forbidden, the f-d transition is a parity allowed transition, so the transition rate is fast and the exciton lifetime of the above organic complex is short. ３＋ (4 ｆ１ Since the fd transition of ) is completely spin-allowed, the transition rate is very fast, comparable to that of fluorescent materials.

[0053] Thus, Ce emits light from the doublet excited state associated with the f-d transition. ３＋ (4 ｆ１ ) and Eu ２＋ (4 ｆ７ The organic complex of (I) is capable of achieving 100% internal quantum efficiency and has a short exciton lifetime, making it a promising luminescent material for achieving high efficiency and reliability in light-emitting devices.

[0054] Ce ３＋ and Eu ２＋ By using the organic complex as a light-emitting material, it is possible to improve the luminous efficiency and reliability of blue light-emitting devices.

[0055] Therefore, in one aspect of the present invention, Ce having three borate ligands is ３＋ The borate ligand is B − And B − In addition, the B − Some or all of the groups that form a covalent bond with Ce ３＋ By using such a borate ligand, it is possible to obtain Ce, which is stable in the excited state and is not easily decomposed by heat. ３＋can produce organic complexes of the formula:

[0056] In the borate ligand, B − As the group that forms a covalent bond with Ce, a heteroaryl group having two or more nitrogen atoms can be used, and specifically, either one or both of a pyrazolyl group and a triazolyl group can be used. By donating the unshared electron pair of the nitrogen atom of the pyrazolyl group or the triazolyl group, the borate ligand can be bonded to Ce. ３＋ can be coordinated to

[0057] However, B − If the total number of pyrazolyl groups and triazolyl groups forming covalent bonds with the organic complex is excessive, the molecular weight of the entire organic complex increases, and there is a concern that the sublimation property of the organic complex may deteriorate. Therefore, a borate ligand in which the number of pyrazolyl groups and triazolyl groups is controlled to a desired number is synthesized, and the borate ligand is then bonded to Ce. ３＋ It is preferable to adjust the total number of pyrazolyl groups and triazolyl groups in the entire organic complex by coordinating them to the above.

[0058] In this specification, even when a pyrazolyl group and a triazolyl group are mentioned, the description can be applied to both an organic complex having both a pyrazolyl group and a triazolyl group, and an organic complex having only one of a pyrazolyl group and a triazolyl group.

[0059] Ce ３＋ The coordination number to the compound is preferably 7 or more and 9 or less, more preferably 8. Therefore, the total number of pyrazolyl groups and triazolyl groups in the organic complex is preferably 7 or more and 9 or less, more preferably 8. By setting the total number of pyrazolyl groups and triazolyl groups in this way, it is possible to provide an organic complex that is stable and has high sublimation properties. Therefore, the organic complex is suitable as a light-emitting material for light-emitting devices.

[0060] In addition, an alkyl group, a cycloalkyl group, or an aryl group may be bonded to one or more of the pyrazolyl group and the triazolyl group of the borate ligand. By changing the type of these substituents, steric hindrance can be controlled, and the borate ligand and Ce can be bonded to each other. ３＋The bond distance between the fluorine atom and the fluorine atom can be changed, which makes it possible to adjust the emission color. Furthermore, by changing the type of these substituents, it is expected that reliability will be improved.

[0061] In addition, in the borate ligand, B − An alkyl group, a cycloalkyl group, or an aryl group may be bonded to the borate ligand. By changing the type of these substituents, steric hindrance can be controlled, and the borate ligand and the Ce ligand can be bonded to the borate ligand. ３＋ The bond distance between the nucleus and the nucleus can be changed, allowing for tuning of the emission color. Furthermore, by changing the type of these substituents, it is expected that the reliability of the organometallic complex will be improved.

[0062] That is, one embodiment of the present invention is an organometallic complex represented by General Formula (G1).

[0063]

[0064] In general formula (G1), X represents carbon or nitrogen, and the carbon is bonded to any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. １ ~R ３ each independently represents one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. n represents an integer of 1 to 4. The borate ligands may be the same or different from each other. The n of each borate ligand may be the same or different from each other. When n is 2 or more, the X of each borate ligand may be the same or different from each other, and the R of each borate ligand may be the same or different from each other. １ may be the same or different, and R of each borate ligand ２ may be the same or different. When n is 2 or less, R ３ may be the same or different from each other.

[0065] Another embodiment of the present invention is an organometallic complex represented by General Formula (G2).

[0066]

[0067] In general formula (G2), R １ ~R ３ each independently represents one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. n represents an integer of 1 to 4. The borate ligands may be the same or different from each other. The n of each borate ligand may be the same or different from each other. When n is 2 or more, the X of each borate ligand may be the same or different from each other, and the R of each borate ligand may be the same or different from each other. １ may be the same or different, and R of each borate ligand ２ may be the same or different. When n is 2 or less, R ３ may be the same or different from each other.

[0068] As in the case of an organometallic complex represented by general formula (G2), a Ce complex having a borate ligand having a triazolyl group is ３＋ When the compound is an organic complex, the ligand field splitting can be reduced, which can increase the molar extinction coefficient.

[0069] As mentioned above, Ce ３＋ The total number of pyrazolyl groups and triazolyl groups in the organic complex is preferably 7 or more and 9 or less, and more preferably 8. Therefore, in general formulas (G1) and (G2), the total of the three n's is preferably 7 or more and 9 or less, and more preferably 8.

[0070] Another embodiment of the present invention is an organometallic complex represented by General Formula (G3).

[0071]

[0072] In general formula (G3), X １ ~X ３ each independently represents carbon or nitrogen, and the carbon is bonded to any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. １１ ~R １３ , R ２１ ~R ２３ and R ３１ ~R ３３ Each of j, k, and p independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. In addition, j, k, and p each independently represent an integer of 1 to 4. When j is 2 or more, each of X １ may be the same or different, and each R １１ may be the same or different, and each R １２ may be the same or different. When k is 2 or more, each X ２ may be the same or different, and each R ２１ may be the same or different, and each R ２２ may be the same or different. When p is 2 or more, each X ３ may be the same or different, and each R ３１ may be the same or different, and each R ３２ may be the same or different. When j is 2 or less, each R １３ may be the same or different. When k is 2 or less, each R ２３ may be the same or different. When p is 2 or less, each R ３３ may be the same or different from each other.

[0073] Another embodiment of the present invention is an organometallic complex represented by a general formula (G3′).

[0074]

[0075] In general formula (G3'), X １ ~X ３ each independently represents carbon or nitrogen, and the carbon is bonded to any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. １１ ~R １３ , R ２１ ~R ２３ and R ３１ ~R ３３ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. j represents an integer of 1 to 3. k and p each independently represent an integer of 1 to 4. When j is 2 or more, each X １ may be the same or different, and each R １１ may be the same or different, and each R １２ may be the same or different. When k is 2 or more, each X ２ may be the same or different, and each R ２１ may be the same or different, and each R ２２ may be the same or different. When p is 2 or more, each X ３ may be the same or different, and each R ３１ may be the same or different, and each R ３２ may be the same or different. When j is 2 or less, each R １３ may be the same or different. When k is 2 or less, each R２３ may be the same or different. When p is 2 or less, each R ３３ may be the same or different from each other.

[0076] Another embodiment of the present invention is an organometallic complex represented by General Formula (G4).

[0077]

[0078] In general formula (G4), X ２ and X ３ each independently represents carbon or nitrogen, and the carbon is bonded to any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. １１ ~R １３ , R ２１ ~R ２３ and R ３１ ~R ３３ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. j, k, and p each independently represent an integer of 1 to 4. When j is 2 or more, each R １１ may be the same or different, and each R １２ may be the same or different. When k is 2 or more, each X ２ may be the same or different, and each R ２１ may be the same or different, and each R ２２ may be the same or different. When p is 2 or more, each X ３ may be the same or different, and each R ３１ may be the same or different, and each R ３２may be the same or different. When j is 2 or less, each R １３ may be the same or different. When k is 2 or less, each R ２３ may be the same or different. When p is 2 or less, each R ３３ may be the same or different from each other.

[0079] As in the case of an organometallic complex represented by general formula (G4), a Ce complex having a borate ligand having at least one triazolyl group is ３＋ By forming an organic complex, it is possible to reduce the ligand field splitting, thereby increasing the molar extinction coefficient.

[0080] As mentioned above, Ce ３＋ The total number of pyrazolyl groups and triazolyl groups in the organic complex is preferably 7 or more and 9 or less, more preferably 8. Therefore, in general formulae (G3), (G3′), and (G4), the total of j, k, and p is preferably 7 or more and 9 or less, more preferably 8.

[0081] Another embodiment of the present invention is an organometallic complex represented by General Formula (G5).

[0082]

[0083] In general formula (G5), X １１ ~X １３ , X ２１ ~X ２３ , X ３１ and X ３２ each independently represents carbon or nitrogen, and the carbon is bonded to any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. ４１ ~R ４７ , R ５１ ~R ５７ and R ６１ ~R ６６each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms.

[0084] As in the organometallic complex represented by the general formula (G5), when an organic complex is prepared having two borate ligands each having three pyrazolyl groups and / or three triazolyl groups, and one borate ligand each having two pyrazolyl groups and / or two triazolyl groups, Ce ３＋ This is preferable because the coordination number can be 8. By using such a structure, it is possible to obtain an organometallic complex that is stable and has high sublimability, and therefore, it is possible to obtain an organometallic complex that is suitable as a light-emitting material for light-emitting devices.

[0085] In the above general formulas (G1) to (G5), specific examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, a neopentyl group, a hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, a neohexyl group, a 3-methylpentyl group, a 2-methylpentyl group, a 2-ethylbutyl group, a 1,2-dimethylbutyl group, a 2,3-dimethylbutyl group, etc. In the case where the alkyl group having 1 to 10 carbon atoms has a substituent, the substituent is an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, or an aryl group having 6 to 13 carbon atoms.

[0086] In the above general formulas (G1) to (G5), specific examples of the cycloalkyl group having 3 to 10 carbon atoms include a cyclopropyl group, a cyclobutyl group, a methylcyclobutyl group, a cyclopentyl group, a methylcyclopentyl group, an isopropylcyclopentyl group, a tert-butylcyclopropyl group, a cyclohexyl group, a methylcyclohexyl group, an isopropylcyclohexyl group, a tert-butylcyclohexyl group, a cycloheptyl group, a methylcycloheptyl group, an isopropylcycloheptyl group, a cyclooctyl group, a methylcyclooctyl group, a cyclononyl group, a methylcyclononyl group, a cyclodecyl group, etc. When a cycloalkyl group having 3 to 10 carbon atoms has a substituent, the substituent is an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, or an aryl group having 6 to 13 carbon atoms.

[0087] In the above general formulas (G1) to (G5), examples of the aryl group having 6 to 30 carbon atoms include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a mesityl group, an o-biphenyl group, an m-biphenyl group, a p-biphenyl group, a 1-naphthyl group, a 2-naphthyl group, a fluorenyl group, a 9,9-dimethylfluorenyl group, a 9,9-diphenylfluorenyl group, a spirofluorenyl group, a phenanthrenyl group, a terphenyl group, an anthracenyl group, a fluoranthenyl group, etc. When the aryl group having 6 to 30 carbon atoms has a substituent, the substituent is an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, or an aryl group having 6 to 13 carbon atoms.

[0088] As mentioned above, by introducing these substituents, the steric hindrance in the organometallic complex can be controlled, and the borate ligand and the Ce ３＋ The bond distance with the methyl group changes, making it possible to adjust the emission color. Furthermore, the introduction of these substituents is expected to improve the reliability of the organometallic complex. For example, the introduction of a methyl group provides a moderate steric hindrance, which can improve the reliability of the organometallic complex.

[0089] Next, specific examples of organometallic complexes which have the structures represented by any of the above general formulas (G1) to (G5) and which are embodiments of the present invention and which can be used in light-emitting devices will be shown below.

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101] The organometallic complexes represented by the above structural formulas (100) to (179) are specific examples of the structures represented by general formulas (G1) to (G5); however, the organometallic complexes of one embodiment of the present invention are not limited thereto.

[0102] Next, a synthesis method for an organometallic complex represented by General Formula (G1) below, which is one embodiment of the present invention, will be described.

[0103]

[0104] In general formula (G1), X represents carbon or nitrogen, and the carbon is bonded to any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. １ ~R ３each independently represents one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. n represents an integer of 1 to 4. The borate ligands may be the same or different from each other. The n of each borate ligand may be the same or different from each other. When n is 2 or more, the X of each borate ligand may be the same or different from each other, and the R of each borate ligand may be the same or different from each other. １ may be the same or different, and R of each borate ligand ２ may be the same or different. When n is 2 or less, R ３ may be the same or different from each other.

[0105] <<Synthesis Method of Organometallic Complex of One Embodiment of the Present Invention>> The organometallic complex of one embodiment of the present invention represented by General Formula (G1) can be obtained by stirring a boron compound having a heteroaromatic ring represented by General Formula (g1), a cerium compound (a trivalent cerium salt such as cerium(III) chloride, cerium(III) nitrate, or cerium(III) trifluoromethanesulfonate), and one or more organic solvents such as an alcohol solvent, tetrahydrofuran, or chloroform under an inert gas atmosphere, as shown in the following synthesis scheme (A-1).

[0106]

[0107] Organometallic complexes represented by other general formulas can also be synthesized in the same manner as above.

[0108] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0109] 1A to 1E, a structure of a light-emitting device using a material that emits light from a doublet excited state as a light-emitting substance in a light-emitting layer will be described. The light-emitting substance is not particularly limited as long as it emits light from a doublet excited state, but it is preferable to use the organometallic complex shown in Embodiment 1.

[0110] <<Basic Structure of Light-Emitting Device>> The basic structure of a light-emitting device will be described. Fig. 1A shows a light-emitting device having an EL layer including a light-emitting layer between a pair of electrodes. Specifically, the light-emitting device has a structure in which an EL layer 103 is sandwiched between a first electrode 101 and a second electrode 102.

[0111] 1B shows a light-emitting device with a stacked structure (tandem structure) having multiple (two in FIG. 1B) EL layers (103a, 103b) between a pair of electrodes, with a charge generation layer 106 between the EL layers. A light-emitting device with a tandem structure can realize a highly efficient light-emitting device without changing the amount of current.

[0112] The charge generation layer 106 has a function of injecting electrons into one EL layer (103a or 103b) and injecting holes into the other EL layer (103b or 103a) when a potential difference is generated between the first electrode 101 and the second electrode 102. Therefore, in Fig. 1B, when a voltage is applied to the first electrode 101 so that the potential is higher than that of the second electrode 102, electrons are injected from the charge generation layer 106 into the EL layer 103a and holes are injected into the EL layer 103b.

[0113] Note that, in terms of light extraction efficiency, the charge generation layer 106 preferably has a light-transmitting property to visible light (specifically, the transmittance of the charge generation layer 106 to visible light is 40% or more). Furthermore, the charge generation layer 106 functions even if it has lower conductivity than the first electrode 101 and the second electrode 102.

[0114] FIG. 1C also shows a stacked structure of the EL layer 103 of the light-emitting device according to one embodiment of the present invention. In this case, the first electrode 101 functions as an anode, and the second electrode 102 functions as a cathode. The EL layer 103 has a structure in which a hole injection layer 111, a hole transport layer 112, a light-emitting layer 113, an electron transport layer 114, and an electron injection layer 115 are sequentially stacked over the first electrode 101. The light-emitting layer 113 may have a stacked structure of multiple light-emitting layers that emit different colors. For example, a light-emitting layer containing a red light-emitting substance, a light-emitting layer containing a green light-emitting substance, and a light-emitting layer containing a blue light-emitting substance may be stacked, or may have a structure in which the layers are stacked with a layer containing a carrier transport material interposed therebetween. Alternatively, a light-emitting layer containing a yellow light-emitting substance and a light-emitting layer containing a blue light-emitting substance may be combined. However, the stacked structure of the light-emitting layer 113 is not limited to the above. For example, the light-emitting layer 113 may be configured by stacking multiple light-emitting layers emitting the same light color. For example, a first light-emitting layer containing a blue light-emitting material and a second light-emitting layer containing a blue light-emitting material may be stacked, or a layer containing a carrier transport material may be interposed between the layers. A configuration in which multiple light-emitting layers emitting the same light color are stacked may provide higher reliability than a single-layer configuration. Even in a tandem structure such as that shown in FIG. 1B , in which multiple EL layers are included, each EL layer is stacked sequentially from the anode side as described above. Furthermore, when the first electrode 101 is a cathode and the second electrode 102 is an anode, the stacking order of the EL layer 103 is reversed. Specifically, the structure includes an electron injection layer 111 on the first electrode 101 (cathode), an electron transport layer 112, an emitting layer 113, a hole transport layer 114, and a hole injection layer 115.

[0115] The light-emitting layer 113 included in the EL layers (103, 103a, and 103b) contains an appropriate combination of multiple substances, including a material that emits light from a doublet excited state. Also, a structure in which different light-emitting colors are obtained from the multiple EL layers (103a and 103b) shown in FIG. 1B may be used. In this case, the light-emitting substance and other substances used in each light-emitting layer may be different materials.

[0116] In addition, in a light-emitting device that is one embodiment of the present invention, for example, the first electrode 101 shown in FIG. 1C is a reflective electrode, the second electrode 102 is a semi-transmissive and semi-reflective electrode, and a micro-optical resonator (microcavity) structure is formed. This allows light emission from the light-emitting layer 113 included in the EL layer 103 to resonate between the two electrodes, thereby enhancing the light emission emitted from the second electrode 102.

[0117] In addition, when the first electrode 101 of the light-emitting device is a reflective electrode having a laminated structure of a reflective conductive material and a light-transmitting conductive material (transparent conductive film), optical adjustment can be performed by controlling the film thickness of the transparent conductive film. Specifically, it is preferable to adjust the optical distance (product of film thickness and refractive index) between the first electrode 101 and the second electrode 102 to mλ / 2 (where m is an integer of 1 or greater) or in the vicinity thereof, for the wavelength λ of light obtained from the light-emitting layer 113.

[0118] Furthermore, in order to amplify the desired light (wavelength: λ) obtained from the light-emitting layer 113, it is preferable to adjust the optical distance from the first electrode 101 to the region (light-emitting region) in the light-emitting layer 113 where the desired light is obtained and the optical distance from the second electrode 102 to the region (light-emitting region) in the light-emitting layer 113 where the desired light is obtained to be (2m'+1)λ / 4 (where m' is an integer of 1 or more) or close to that. Note that the light-emitting region referred to here refers to a recombination region of holes and electrons in the light-emitting layer 113.

[0119] By performing such optical adjustment, the spectrum of the specific monochromatic light obtained from the light-emitting layer 113 can be narrowed, and light emission with good color purity can be obtained.

[0120] However, in the above case, the optical distance between the first electrode 101 and the second electrode 102 can be strictly defined as the total thickness from the reflective region of the first electrode 101 to the reflective region of the second electrode 102. However, since it is difficult to precisely determine the reflective regions of the first electrode 101 and the second electrode 102, the above-mentioned effect can be sufficiently achieved by assuming any position of the first electrode 101 and the second electrode 102 as the reflective region. Furthermore, the optical distance between the first electrode 101 and the light-emitting layer from which desired light is obtained can be strictly defined as the optical distance between the reflective region of the first electrode 101 and the light-emitting region of the light-emitting layer from which desired light is obtained. However, since it is difficult to precisely determine the reflective region of the first electrode 101 and the light-emitting region of the light-emitting layer from which desired light is obtained, the above-mentioned effect can be sufficiently achieved by assuming any position of the first electrode 101 as the reflective region and any position of the light-emitting layer from which desired light is obtained as the light-emitting region.

[0121] The light-emitting device shown in FIG. 1D is a light-emitting device with a tandem structure and a microcavity structure, which allows light of different wavelengths (monochromatic light) to be extracted from each EL layer (103a, 103b). Therefore, separate coloring (e.g., RGB) to obtain different emitted colors is not required. This makes it easy to achieve high definition. It can also be combined with a colored layer (color filter). Furthermore, it is possible to increase the emission intensity of a specific wavelength in the front direction, thereby reducing power consumption.

[0122] The light-emitting device shown in FIG. 1E is an example of the tandem-structure light-emitting device shown in FIG. 1B. As shown in the figure, the light-emitting device has a structure in which three EL layers (103a, 103b, 103c) are stacked with charge-generating layers (106a, 106b) sandwiched between them. Each of the three EL layers (103a, 103b, 103c) has a light-emitting layer (113a, 113b, 113c), and the light-emitting colors of the light-emitting layers can be freely combined. For example, the light-emitting layer 113a can be blue, the light-emitting layer 113b can be red, green, or yellow, and the light-emitting layer 113c can be blue. Alternatively, the light-emitting layer 113a can be red, the light-emitting layer 113b can be blue, green, or yellow, and the light-emitting layer 113c can be red.

[0123] In the light-emitting device according to one embodiment of the present invention, at least one of the first electrode 101 and the second electrode 102 is a light-transmitting electrode (such as a transparent electrode or a semi-transmitting / semi-reflective electrode). When the light-transmitting electrode is a transparent electrode, the visible light transmittance of the transparent electrode is set to 40% or more. When the semi-transmitting / semi-reflective electrode is used, the visible light reflectance of the semi-transmitting / semi-reflective electrode is set to 20% or more and 80% or less, preferably 40% or more and 70% or less. Furthermore, these electrodes have a resistivity of 1×10 −２ It is preferable that the resistance is Ωcm or less.

[0124] In the above-described light-emitting device according to one embodiment of the present invention, when one of the first electrode 101 and the second electrode 102 is a reflective electrode (a reflective electrode), the reflectivity of the reflective electrode for visible light is set to 40% or more and 100% or less, preferably 70% or more and 100% or less. −２ It is preferable that the resistance is Ωcm or less.

[0125] <<Specific Structure of Light-Emitting Device>> Next, a specific structure of a light-emitting device according to one embodiment of the present invention will be described. Here, the description will be made with reference to FIG. 1D having a tandem structure. The same applies to the EL layer configuration of the single-structure light-emitting devices shown in FIGS. 1A and 1C. When the light-emitting device shown in FIG. 1D has a microcavity structure, the first electrode 101 is formed as a reflective electrode, and the second electrode 102 is formed as a semi-transparent and semi-reflective electrode. Therefore, the electrode 102 can be formed as a single layer or a stacked layer using a single or multiple desired electrode materials. The second electrode 102 is formed by selecting an appropriate material after the EL layer 103b is formed.

[0126] <First Electrode and Second Electrode> The materials forming the first electrode 101 and the second electrode 102 can be appropriately combined from the following materials as long as they fulfill the functions of both electrodes described above. For example, metals, alloys, electrically conductive compounds, and mixtures thereof can be appropriately used. Specific examples include In-Sn oxide (also referred to as ITO), In-Si-Sn oxide (also referred to as ITSO), In-Zn oxide, and In-W-Zn oxide. Other metals that can be used include aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), and neodymium (Nd), as well as alloys containing appropriate combinations of these metals. Other examples that can be used include elements belonging to Group 1 or 2 of the periodic table (e.g., lithium (Li), cesium (Cs), calcium (Ca), and strontium (Sr)) that are not listed above, rare earth metals such as europium (Eu) and ytterbium (Yb), and alloys containing appropriate combinations of these, as well as graphene.

[0127] 1D , when the first electrode 101 is an anode, the hole injection layer 111a and the hole transport layer 112a of the EL layer 103a are sequentially formed by vacuum deposition on the first electrode 101. After the EL layer 103a and the charge generation layer 106 are formed, the hole injection layer 111b and the hole transport layer 112b of the EL layer 103b are similarly sequentially formed on the charge generation layer 106.

[0128] <Hole injection layer> The hole injection layer (111, 111a, 111b) is a layer that injects holes from the first electrode 101, which is an anode, and the charge generation layer (106, 106a, 106b) to the EL layer (103, 103a, 103b), and is a layer that contains an organic acceptor material and a material with high hole injection properties.

[0129] An organic acceptor material is a material that can generate holes in an organic compound by causing charge separation between the organic compound and another organic compound having a LUMO (Lowest Unoccupied Molecular Orbital) level value close to the HOMO (Highest Occupied Molecular Orbital) level value. Therefore, as the organic acceptor material, compounds having an electron-withdrawing group (halogen group or cyano group), such as quinodimethane derivatives, chloranil derivatives, and hexaazatriphenylene derivatives, can be used. For example, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviated as F ４Examples of organic acceptor materials that can be used include 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCCNNQ), and 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile. Among organic acceptor materials, compounds such as HAT-CN in which an electron-withdrawing group is bonded to a fused aromatic ring having multiple heteroatoms are particularly suitable because of their high acceptor properties and stable film quality against heat. In addition, [3]radialene derivatives having an electron-withdrawing group (particularly a halogen group such as a fluoro group or a cyano group) are preferred because they have extremely high electron-accepting properties. Specifically, α,α',α''-1,2,3-cyclopropanetriylidene tris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidene tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidene tris[2,3,4,5,6-pentafluorobenzeneacetonitrile], etc. can be used.

[0130] As a material with high hole injection properties, oxides of metals belonging to Groups 4 to 8 of the periodic table (transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, manganese oxide, etc.) can be used. Specific examples include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among the above, molybdenum oxide is preferred because it is stable in the air, has low hygroscopicity, and is easy to handle. In addition, phthalocyanine (abbreviated as H ２ Phthalocyanine compounds such as copper phthalocyanine (abbreviated as CuPc) or copper phthalocyanine (abbreviated as CuPc) can be used.

[0131] In addition to the above materials, low molecular weight compounds such as 4,4',4''-tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4',4''-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: MTDATA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), N,N'-bis[4-bis(3-methylphenyl)aminophenyl]-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: DNTPD), 1,3,5-tris[N Aromatic amine compounds such as 3-[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), 3-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), and 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1) can be used.

[0132] Also usable are polymer compounds (oligomers, dendrimers, polymers, etc.), such as poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD). Alternatively, polymer compounds to which an acid has been added, such as poly(3,4-ethylenedioxythiophene) / polystyrenesulfonic acid (abbreviation: PEDOT / PSS) and polyaniline / polystyrenesulfonic acid (abbreviation: PAni / PSS), can also be used.

[0133] Furthermore, as the material with high hole injection properties, a mixed material containing a hole transport material and the above-mentioned organic acceptor material (electron accepting material) can also be used. In this case, electrons are extracted from the hole transport material by the organic acceptor material, generating holes in the hole injection layer 111, and the holes are injected into the light-emitting layer 113 via the hole transport layer 112. Note that the hole injection layer 111 may be formed as a single layer made of a mixed material containing the hole transport material and the organic acceptor material (electron accepting material), or may be formed by laminating the hole transport material and the organic acceptor material (electron accepting material) as separate layers.

[0134] The hole transport material has a hole mobility of 1×10 when the square root of the electric field strength [V / cm] is 600. −６ cm ２ A substance having a hole mobility of 1 / Vs or more is preferred. Note that other substances can also be used as long as they have a higher hole transporting property than electron transporting property.

[0135] As the hole-transporting material, a material with high hole-transporting properties, such as a compound having a π-electron-rich heteroaromatic ring (e.g., a carbazole derivative, a furan derivative, or a thiophene derivative) and an aromatic amine (an organic compound having an aromatic amine skeleton), is preferred.

[0136] Examples of the carbazole derivatives (organic compounds having a carbazole ring) include bicarbazole derivatives (for example, 3,3'-bicarbazole derivatives), aromatic amines having a carbazolyl group, and the like.

[0137] Specific examples of the bicarbazole derivatives (e.g., 3,3′-bicarbazole derivatives) include 3,3′-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), 9,9′-bis(biphenyl-4-yl)-3,3′-bi-9H-carbazole (abbreviation: BisBPCz), 9,9′-bis(1,1′-biphenyl-3-yl)-3,3′-bi-9H-carbazole (abbreviation: BismBPCz), 9-(1,1′-biphenyl-3-yl)-9′-(1,1′-biphenyl-4-yl)-9H,9′H-3,3′-bicarbazole (abbreviation: mBPCCBP), and 9-(2-naphthyl)-9′-phenyl-9H,9′H-3,3′-bicarbazole (abbreviation: βNCCP).

[0138] Specific examples of the aromatic amine having a carbazolyl group include 4-phenyl-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazol-3-amine (abbreviation: PCBiF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF), N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-bis(9,9-dimethyl-9H-fluoren-2-yl)amine (abbreviation: PCBFF), N-(1,1′-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-4-amine, N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-(9,9-dimethyl-9H-fluoren-2-yl)-9,9-dimethyl-9H-fluorene- 4-amine, N-(1,1′-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-diphenyl-9H-fluoren-2-amine, N-(1,1′-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-diphenyl-9H-fluoren-4-amine, N-(1,1′-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9′-spirobi(9H-fluorene) -2-amine, N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi(9H-fluoren)-4-amine, N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-(1,1':3',1''-terphenyl-4-yl)-9,9-dimethyl-9H-fluoren-2-amine, N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-(1,1':4',1''-terphenyl-4-yl)-9,9-dimethyl-9H-fluoren-2-amine, N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-(1,1':3',1''-terphenyl-4-yl)-9,9-dimethyl-9H-fluoren-4-amine, N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-(1,1':4',1''-terphenyl-4-yl)-9,9-dimethyl-9H-fluoren-4-amine, 4,4'-diphenyl-4''-(9-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: PCBNBB), 4-phenyldiphenyl-(9-phenyl-9H-carbazol-3-yl)amine (abbreviation: PCA1BP), N,N'-bis(9-phenylcarbazol-3-yl)-N,N'-diphenylbenzene-1,3-diamine (abbreviation: PCA2B), N,N',N''-triphenyl-N,N',N''-tris(9-phenylcarbazol-3-yl)benzene-1,3,5-triamine (abbreviation: PCA3B), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), 3-[N-(9-phenyl) 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1), 3-[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA1), 3,6-bis[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA2), 3,6-bis[N-(4-diphenylaminophenyl)-N-(1-naphthyl)amino]-9-phenylcarbazole (abbreviation: PCzTPN2), 2-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]spiro-9,9′-bifluorene (abbreviation: PCAS F), N-[4-(9H-carbazol-9-yl)phenyl]-N-(4-phenyl)phenylaniline (abbreviation: YGA1BP), N,N'-bis[4-(carbazol-9-yl)phenyl]-N,N'-diphenyl-9,9-dimethylfluorene-2,7-diamine (abbreviation: YGA2F), 4,4',4''-tris(carbazol-9-yl)triphenylamine (abbreviation: TCTA), and the like.

[0139] In addition to the above, examples of the carbazole derivatives include 9-[4-(9-phenyl-9H-carbazol-3-yl)-phenyl]phenanthrene (abbreviation: PCPPn), 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4′-di(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviation: TCPB), and 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA).

[0140] Specific examples of the furan derivatives (organic compounds having a furan ring) include 4,4′,4″-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II).

[0141] Specific examples of the thiophene derivatives (organic compounds having a thiophene ring) include 4,4′,4″-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV).

[0142] Specific examples of the aromatic amine include 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB or α-NPD), N,N′-diphenyl-N,N′-bis(3-methylphenyl)-4,4′-diaminobiphenyl (abbreviation: TPD), N,N′-bis(9,9′-spirobi[9H-fluoren]-2-yl)-N,N′-diphenyl-4,4′-diaminobiphenyl (abbreviation: BSPB), and 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP). ), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), N-(9,9-dimethyl-9H-fluoren-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-fluoren-7-yl)diphenylamine (abbreviation: DPNF), 2-[N-(4-diphenylaminophenyl )-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: DPASF), 2,7-bis[N-(4-diphenylaminophenyl)-N-phenylamino]-spiro-9,9'-bifluorene (abbreviation: DPA2SF), 4,4',4''-tris[N-(1-naphthyl)-N-phenylamino]triphenylamine (abbreviation: 1'-TNATA), 4,4',4''-tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4',4''-tris[N-(3-methylphenyl)-N-phenylamino] triphenylamine (abbreviation: m-MTDATA), N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), DNTPD, 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4′-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4″-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2- d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4′, 4''-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4''-( 7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-Diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine ]-4''-phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazol-9-yl)phenyl N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9′-spirobi[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N, N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), N,N-bis(9, ... N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-1-amine, and the like are mentioned.

[0143] Other examples of hole-transporting materials that can be used include polymer compounds (oligomers, dendrimers, polymers, etc.) such as poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD). Alternatively, polymer compounds to which an acid has been added, such as poly(3,4-ethylenedioxythiophene) / polystyrenesulfonic acid (abbreviation: PEDOT / PSS) and polyaniline / polystyrenesulfonic acid (abbreviation: PAni / PSS), can also be used.

[0144] However, the hole transporting material is not limited to the above, and various known materials may be used alone or in combination as the hole transporting material.

[0145] The hole injection layers (111, 111a, 111b) can be formed using various known film formation methods, for example, vacuum deposition.

[0146] <Hole transport layer> The hole transport layer (112, 112a, 112b) is a layer that transports holes injected from the first electrode 101 by the hole injection layer (111, 111a, 111b) to the light-emitting layer (113, 113a, 113b, 113c). The hole transport layer (112, 112a, 112b) is a layer that contains a hole transport material. Therefore, the hole transport layer (112, 112a, 112b) can be made of the same hole transport material that can be used for the hole injection layer (111, 111a, 111b).

[0147] In the light-emitting device of one embodiment of the present invention, the same organic compound as that of the hole-transport layer (112, 112a, 112b) can be used for the light-emitting layer (113, 113a, 113b, 113c). It is more preferable to use the same organic compound for the hole-transport layer (112, 112a, 112b) and the light-emitting layer (113, 113a, 113b, 113c) because holes can be efficiently transported from the hole-transport layer (112, 112a, 112b) to the light-emitting layer (113, 113a, 113b, 113c).

[0148] <Light-emitting layer> The light-emitting layers (113, 113a, 113b, and 113c) are layers containing a light-emitting substance. A material that emits light from a doublet excited state can be used as the light-emitting substance. The light-emitting substance is not particularly limited as long as it is a material that emits light from a doublet excited state; however, it is preferable to use the organometallic complex described in Embodiment 1. Furthermore, the light-emitting layers (113, 113a, 113b, and 113c) may contain one or more organic compounds (host materials or the like) in addition to a light-emitting substance (guest material).

[0149] Examples of the organic compound used as the host material include organic compounds such as hole-transporting materials that can be used in the hole-transporting layers (112, 112a, 112b) described above and electron-transporting materials that can be used in the electron-transporting layers (114, 114a, 114b) described below, as long as they satisfy the conditions for a host material used in an emitting layer.

[0150] Here, the present inventors have found that when a material that emits light from a doublet excited state is used as a light-emitting substance in an emitting layer, the host material preferably contains an electron-transporting heteroaromatic compound. Considering the carrier transport property of the doublet light-emitting material, it is preferable that the host material transports electrons, and a heteroaromatic ring is stable as an electron-transporting skeleton. The electron-transporting heteroaromatic compound used as the host material is preferably a π-electron-deficient heteroaromatic compound. The light-emitting substance in this case is not particularly limited as long as it emits light from a doublet excited state, but the organometallic complex shown in Embodiment 1 is preferred.

[0151] Specific examples of the π-electron-deficient heteroaromatic compound include compounds containing a nitrogen-containing 6-membered heteroaromatic ring, such as phenanthroline derivatives, quinoline derivatives, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, diazine (pyrimidine, pyrazine, pyridazine) derivatives, and triazine derivatives. The heteroaromatic ring of these derivatives may be further condensed with an aromatic ring such as a benzene ring. Specific examples of the π-electron-deficient heteroaromatic compound are not limited to these, and the π-electron-deficient heteroaromatic compound can be selected from organic compounds such as the hole-transporting materials described above or the electron-transporting materials described below.

[0152] <Electron Transport Layer> The electron transport layers (114, 114a, 114b) are layers that transport electrons injected from the second electrode 102 and the charge generation layers (106, 106a, 106b) by the electron injection layers (115, 115a, 115b) described later to the light-emitting layers (113, 113a, 113b, 113c). Note that the heat resistance of the light-emitting device according to one embodiment of the present invention can be improved by the electron transport layer having a stacked structure. In addition, the electron transport material used for the electron transport layers (114, 114a, 114b) has an electron mobility of 1×10 or more at a square root of an electric field strength [V / cm] of 600. −６ cm ２A substance having an electron mobility of 1 / Vs or higher is preferred. Note that other substances can be used as long as they have a higher electron transporting property than holes. The electron transport layer (114, 114a, 114b) functions as a single layer, but may also have a stacked structure of two or more layers. Note that the above mixed materials have heat resistance, and therefore, by performing a photolithography process on the electron transport layer using such a mixed material, the influence of a thermal process on the device characteristics can be suppressed.

[0153] <Electron Transporting Material> As the electron transporting material that can be used in the electron transporting layer (114, 114a, 114b), an organic compound with high electron transporting properties can be used, for example, a heteroaromatic compound. A heteroaromatic compound is a cyclic compound containing at least two different elements in a ring. The ring structure includes a three-membered ring, a four-membered ring, a five-membered ring, a six-membered ring, etc., but a five-membered ring or a six-membered ring is particularly preferred. The contained element is preferably a heteroaromatic compound containing one or more of nitrogen, oxygen, sulfur, or the like in addition to carbon. In particular, a nitrogen-containing heteroaromatic compound (nitrogen-containing heteroaromatic compound) is preferred, and it is preferable to use a material with high electron transporting properties (electron transporting material) such as a nitrogen-containing heteroaromatic compound or a π-electron-deficient heteroaromatic compound containing the same.

[0154] The electron transport material may be different from the material used in the light-emitting layer. Not all of the excitons generated by carrier recombination in the light-emitting layer can contribute to light emission, and some may diffuse to layers adjacent to or adjacent to the light-emitting layer. To avoid this phenomenon, it is preferable to use a material different from the material used in the light-emitting layer as the electron transport material. This allows for a highly efficient device.

[0155] A heteroaromatic compound is an organic compound that contains at least one heteroaromatic ring.

[0156] The heteroaromatic ring has any one of a pyridine ring, a diazine ring, a triazine ring, a polyazole ring, an oxazole ring, a thiazole ring, etc. The heteroaromatic ring having a diazine ring includes a heteroaromatic ring having a pyrimidine ring, a pyrazine ring, a pyridazine ring, etc. The heteroaromatic ring having a polyazole ring includes a heteroaromatic ring having an imidazole ring, a triazole ring, or an oxadiazole ring.

[0157] The heteroaromatic ring also includes a fused heteroaromatic ring having a fused ring structure, such as a quinoline ring, a benzoquinoline ring, a quinoxaline ring, a dibenzoquinoxaline ring, a quinazoline ring, a benzoquinazoline ring, a dibenzoquinazoline ring, a phenanthroline ring, a phlodiazin ring, or a benzimidazole ring.

[0158] Among heteroaromatic compounds containing one or more of nitrogen, oxygen, and sulfur in addition to carbon, examples of heteroaromatic compounds having a five-membered ring structure include heteroaromatic compounds having an imidazole ring, heteroaromatic compounds having a triazole ring, heteroaromatic compounds having an oxazole ring, heteroaromatic compounds having an oxadiazole ring, heteroaromatic compounds having a thiazole ring, and heteroaromatic compounds having a benzimidazole ring.

[0159] Furthermore, among heteroaromatic compounds containing one or more of nitrogen, oxygen, and sulfur in addition to carbon, examples of heteroaromatic compounds having a six-membered ring structure include heteroaromatic compounds having a heteroaromatic ring such as a pyridine ring, a diazine ring (including a pyrimidine ring, a pyrazine ring, and a pyridazine ring), a triazine ring, and a polyazole ring.Heteroaromatic compounds having a structure in which pyridine rings are linked include heteroaromatic compounds having a bipyridine structure and heteroaromatic compounds having a terpyridine structure.

[0160] Furthermore, examples of heteroaromatic compounds having a fused ring structure partially containing the above-mentioned 6-membered ring structure include heteroaromatic compounds having a fused heteroaromatic ring such as a quinoline ring, a benzoquinoline ring, a quinoxaline ring, a dibenzoquinoxaline ring, a phenanthroline ring, a furodiazine ring (including a structure in which an aromatic ring is fused to the furan ring of a furodiazine ring), and a benzimidazole ring.

[0161] Specific examples of the heteroaromatic compound having a five-membered ring structure (such as a polyazole ring (including an imidazole ring, a triazole ring, and an oxadiazole ring), an oxazole ring, a thiazole ring, and a benzimidazole ring) include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 3-(4-biphenylyl)-4-furan (abbreviation: OXD-7 ... phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenylyl)-1,2,4-triazole (abbreviation: p-EtTAZ), 2,2′,2″-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4′-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs), and the like.

[0162] Specific examples of the heteroaromatic compound having a 6-membered ring structure (including a heteroaromatic ring having a pyridine ring, a diazine ring, a triazine ring, or the like) include heteroaromatic compounds having a pyridine ring, such as 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy) and 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB); Triazine (abbreviation: PCCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-[3'-(triphenylen-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mTp BPTzn), 2-(biphenyl-4-yl)-4-phenyl-6-(9,9'-spirobi[9H-fluoren]-2-yl)-1,3,5-triazine (abbreviation: BP-SFTzn), 2,6-bis(4-naphthalen-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-(biphenyl-3-yl)-4-phenyl-6- heteroaromatic compounds containing a heteroaromatic ring having a triazine ring, such as {8-[(1,1':4',1''-terphenyl)-4-yl]-1-dibenzofuranyl}-1,3,5-triazine (abbreviation: mBP-TPDBfTzn), 2-{3-[3-(dibenzothiophen-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTzn), and 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn);6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 9,9'-[pyrimidine-4,6-diylbis(biphenyl-3,3'-diyl)]bis(9H-carbazole) (abbreviation: 4,6mCzBP2Pm), 6-(biphenyl-3-yl)-4-[3,5-bis (9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 4-[3-(dibenzothiophen-4-yl)phenyl]-8-(naphthalen-2-yl)-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8βN-4mDBtPBfpm), 8-(1,1′-biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]- 9-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 9-[3'-(dibenzothiophen-4-yl)biphenyl-4-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9pmDBtBPNfpr), 3,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzo Furo[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2'-binaphthalen)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,and heteroaromatic compounds containing a heteroaromatic ring having a diazine (pyrimidine) ring, such as 8(βN2)-4mDBtPBfpm. The aromatic compounds containing a heteroaromatic ring include heteroaromatic compounds having a condensed heteroaromatic ring.

[0163] Other examples include 2,2'-(pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6(P-Bqn)2Py), 2,2'-(2,2'-bipyridine-6,6'-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 6,6'(P-Bqn)2BPy), 2,2'-(pyridine-2,6-diyl)bis{4-[4-(2-naphthyl)phenyl]-6-phenylpyrimidine} (abbreviation: 2,6(NP-PPm)2Py), and 6-(biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mB and heteroaromatic compounds containing a heteroaromatic ring having a triazine ring, such as 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine (abbreviation: TmPPPyTz), 2,4,6-tris(2-pyridyl)-1,3,5-triazine (abbreviation: 2Py3Tz), and 2-[3-(2,6-dimethyl-3-pyridyl)-5-(9-phenanthrenyl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTzn).

[0164] Specific examples of the heteroaromatic compound having a fused ring structure partially containing a 6-membered ring structure (heteroaromatic compound having a fused ring structure) include bathophenanthroline (abbreviation: Bphen), bathocuproine (abbreviation: BCP), 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2′-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline), 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3-(dibenzothiophen-4-yl)biphenyl-3-yl ... mDBTBPDBq-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: 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 2-[4′-(9-phenyl-9H-carbazol-3-yl)-3,1′-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), and other heteroaromatic compounds having a quinoxaline ring.

[0165] In addition to the heteroaromatic compounds described above, the electron transport layers (114, 114a, 114b) may also include the following metal complexes: tris(8-quinolinolato)aluminum(III) (abbreviation: Alq ３ ), tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq ３ ), 8-quinolinolato-lithium (abbreviation: Liq), BeBq ２metal complexes having a quinoline ring or a benzoquinoline ring, such as bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq) and bis(8-quinolinolato)zinc(II) (abbreviation: Znq); and metal complexes having an oxazole ring or a thiazole ring, such as bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO) and bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ).

[0166] Furthermore, polymer compounds such as poly(2,5-pyridinediyl) (abbreviation: PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviation: PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2′-bipyridine-6,6′-diyl)] (abbreviation: PF-BPy) can also be used as the electron transport material.

[0167] The electron transport layer (114, 114a, 114b) may have not only a single layer structure but also a structure in which two or more layers made of the above-mentioned substances are stacked.

[0168] <Electron injection layer> The electron injection layer (115, 115a, 115b) is a layer containing a substance with high electron injection properties. The electron injection layer (115, 115a, 115b) is a layer for increasing the efficiency of electron injection from the second electrode 102, and it is preferable to use a material having a small difference (0.5 eV or less) between the work function value of the material used for the second electrode 102 and the LUMO level value of the material used for the electron injection layer (115, 115a, 115b). Therefore, the electron injection layer 115 is preferably made of lithium, cesium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF ２ ), 8-quinolinolato-lithium (abbreviation: Liq), 2-(2-pyridyl)phenolatolithium (abbreviation: LiPP), 2-(2-pyridyl)-3-pyridinolatolithium (abbreviation: LiPPy), 4-phenyl-2-(2-pyridyl)phenolatolithium (abbreviation: LiPPP), lithium oxide (LiO ｘ), alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. Also, erbium fluoride (ErF ３ A rare earth metal or a rare earth metal compound such as ytterbium (Yb) or ytterbium (Yb) can be used. The electron injection layer (115, 115a, 115b) may be formed by mixing a plurality of the above materials, or may be formed by stacking a plurality of the above materials. The electron injection layer (115, 115a, 115b) may also be formed by using an electride. Examples of the electride include a substance in which a high concentration of electrons is added to a mixed oxide of calcium and aluminum. The substances that constitute the above-mentioned electron transport layer (114, 114a, 114b) can also be used.

[0169] The electron injection layer (115, 115a, 115b) may also be formed using a mixed material comprising an organic compound and an electron donor (donor). Such a mixed material has excellent electron injection and electron transport properties because electrons are generated in the organic compound by the electron donor. In this case, the organic compound is preferably a material that is excellent at transporting the generated electrons. Specifically, the electron transport materials (metal complexes, heteroaromatic compounds, etc.) used in the electron transport layer (114, 114a, 114b) described above can be used. The electron donor may be any substance that exhibits electron donating properties to the organic compound. Specifically, alkali metals, alkaline earth metals, and rare earth metals are preferred, such as lithium, cesium, magnesium, calcium, erbium, and ytterbium. Alkali metal oxides and alkaline earth metal oxides are preferred, such as lithium oxide, calcium oxide, and barium oxide. Lewis bases such as magnesium oxide can also be used. Organic compounds such as tetrathiafulvalene (abbreviated as TTF) can also be used. Furthermore, a plurality of these materials may be laminated.

[0170] Alternatively, the electron injection layer (115, 115a, 115b) may be made of a mixed material obtained by mixing an organic compound and a metal. The organic compound used here preferably has a LUMO level of −3.6 eV or more and −2.3 eV or less. A material having an unshared electron pair is also preferred.

[0171] Therefore, the organic compound used in the mixed material may be a mixed material obtained by mixing a heteroaromatic compound with a metal, as described above as being usable in the electron transport layer. Preferred heteroaromatic compounds include heteroaromatic compounds having a five-membered ring structure (such as an imidazole ring, a triazole ring, an oxazole ring, an oxadiazole ring, a thiazole ring, or a benzimidazole ring), heteroaromatic compounds having a six-membered ring structure (such as a pyridine ring, a diazine ring (including a pyrimidine ring, a pyrazine ring, or a pyridazine ring), a triazine ring, a bipyridine ring, or a terpyridine ring), and heteroaromatic compounds having a fused ring structure partially including a six-membered ring structure (such as a quinoline ring, a benzoquinoline ring, a quinoxaline ring, a dibenzoquinoxaline ring, or a phenanthroline ring). Specific materials are described above, and therefore will not be described here.

[0172] As the metal used in the mixed material, it is preferable to use a transition metal belonging to Group 5, Group 7, Group 9 or Group 11 in the periodic table and a material belonging to Group 13, such as Ag, Cu, Al or In. In this case, the organic compound forms a Singly Occupied Molecular Orbital (SOMO) with the transition metal.

[0173] For example, when light obtained from the light-emitting layer 113b is to be amplified, the optical distance between the second electrode 102 and the light-emitting layer 113b is preferably less than ¼ of the wavelength λ of light emitted by the light-emitting layer 113b. In this case, the optical distance can be adjusted by changing the film thickness of the electron-transporting layer 114b or the electron-injecting layer 115b.

[0174] Furthermore, as in the light-emitting device shown in FIG. 1D, by providing a charge generation layer 106 between two EL layers (103 a, 103 b), a structure in which multiple EL layers are stacked between a pair of electrodes (also referred to as a tandem structure) can be formed.

[0175] <Charge Generation Layer> The charge generation layer 106 has a function of injecting electrons into the EL layer 103a and injecting holes into the EL layer 103b when a voltage is applied between the first electrode (anode) 101 and the second electrode (cathode) 102. The charge generation layer 106 may be a structure in which an electron acceptor is added to a hole transporting material (also referred to as a P-type layer) or a structure in which an electron donor is added to an electron transporting material (also referred to as an electron injection buffer layer). Alternatively, both of these structures may be stacked. Furthermore, an electron relay layer may be provided between the P-type layer and the electron injection buffer layer. Forming the charge generation layer 106 using the above-described material can suppress an increase in driving voltage when EL layers are stacked.

[0176] In the case where the charge generation layer 106 has a structure (a p-type layer) in which an electron acceptor is added to a hole transporting material that is an organic compound, the material shown in this embodiment mode can be used as the hole transporting material. ４ -TCNQ), chloranil, etc. Also, oxides of metals belonging to Groups 4 to 8 of the periodic table can be used. Specific examples include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide. The acceptor materials described above may also be used. Furthermore, a mixed film obtained by mixing materials constituting the P-type layer may be used, or single films containing each material may be stacked.

[0177] In addition, when the charge generation layer 106 has a structure in which an electron donor is added to an electron transporting material (electron injection buffer layer), the material shown in this embodiment can be used as the electron transporting material. In addition, as the electron donor, an alkali metal, an alkaline earth metal, a rare earth metal, or a metal belonging to Group 2 or Group 13 in the periodic table, or an oxide or carbonate thereof can be used. Specifically, lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium oxide (Li ２ It is preferable to use cesium carbonate, cesium carbonate, etc. Also, an organic compound such as tetrathianaphthacene may be used as the electron donor.

[0178] When an electron relay layer is provided between the P-type layer and the electron injection buffer layer in the charge generation layer 106, the electron relay layer contains at least a substance having electron transport properties and has the function of preventing interaction between the electron injection buffer layer and the P-type layer and smoothly transferring electrons. The LUMO level of the substance having electron transport properties contained in the electron relay layer is preferably between the LUMO level of the acceptor substance in the P-type layer and the LUMO level of the substance having electron transport properties contained in the electron transport layer in contact with the charge generation layer 106. The specific energy level of the LUMO level of the substance having electron transport properties used in the electron relay layer is −5.0 eV or higher, preferably −5.0 eV or higher and −3.0 eV or lower. Note that the substance having electron transport properties used in the electron relay layer is preferably a phthalocyanine-based material or a metal complex having a metal-oxygen bond and an aromatic ligand.

[0179] Although FIG. 1D shows a structure in which the EL layer 103 has two stacked layers, a stacked structure of three or more EL layers may be used by providing a charge generating layer between different EL layers.

[0180] 1A to 1E, a capping layer may be provided on the second electrode 102 of the light-emitting device. For example, a material with a high refractive index may be used for the capping layer. By providing the capping layer on the second electrode 102, the extraction efficiency of light emitted from the second electrode 102 can be improved.

[0181] Specific examples of materials that can be used for the cap layer include 5,5'-diphenyl-2,2'-di-5H-[1]benzothieno[3,2-c]carbazole (abbreviation: BisBTc), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), etc.

[0182] <Substrate> The light-emitting device described in this embodiment can be formed on various substrates. Note that the type of substrate is not limited to a specific one. Examples of the substrate include a semiconductor substrate (for example, a single crystal substrate or a silicon substrate), an SOI substrate, a glass substrate, a quartz substrate, a plastic substrate, a metal substrate, a stainless steel substrate, a substrate having stainless steel foil, a tungsten substrate, a substrate having tungsten foil, a flexible substrate, a laminated film, paper containing a fibrous material, or a base film.

[0183] Examples of glass substrates include barium borosilicate glass, aluminoborosilicate glass, soda lime glass, etc. Examples of flexible substrates, laminated films, base films, etc. include plastics such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyethersulfone (PES), synthetic resins such as acrylic resins, polypropylene, polyester, polyvinyl fluoride, polyvinyl chloride, polyamide, polyimide, aramid, epoxy resins, inorganic vapor deposition films, and papers.

[0184] Note that the light-emitting device described in this embodiment can be fabricated using a gas phase method such as vapor deposition, a spin coating method, or a liquid phase method such as an inkjet method. When a vapor deposition method is used, a physical vapor deposition (PVD) method such as sputtering, ion plating, ion beam deposition, molecular beam deposition, or vacuum deposition, a chemical vapor deposition (CVD) method, or the like can be used. In particular, layers having various functions included in the EL layer of the light-emitting device (hole injection layer 111, hole transport layer 112, light-emitting layer 113, electron transport layer 114, and electron injection layer 115) can be formed by a vapor deposition method (vacuum deposition, etc.), a coating method (dip coating, die coating, bar coating, spin coating, spray coating, etc.), a printing method (inkjet printing, screen (stencil printing), offset (lithographic printing), flexography (relief printing), gravure printing, microcontact printing, etc.), or the like.

[0185] When applying a film formation method such as the coating method or printing method, it is possible to use high molecular weight compounds (oligomers, dendrimers, polymers, etc.), medium molecular weight compounds (compounds in the intermediate range between low molecular weight and high molecular weight: molecular weight of 400 to 4000), inorganic compounds (quantum dot materials, etc.), etc. As the quantum dot material, it is possible to use colloidal quantum dot materials, alloy type quantum dot materials, core-shell type quantum dot materials, core type quantum dot materials, etc.

[0186] The materials for the layers (hole injection layer 111, hole transport layer 112, light-emitting layer 113, electron transport layer 114, and electron injection layer 115) constituting the EL layer 103 of the light-emitting device described in this embodiment mode are not limited to those described in this embodiment mode, and other materials can be used in combination as long as they can fulfill the functions of the respective layers.

[0187] In this specification and the like, the terms "layer" and "film" can be used interchangeably as appropriate.

[0188] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0189] In this embodiment, a light-emitting and receiving device 700 will be described to explain a specific configuration example and a manufacturing method example of the light-emitting and receiving device according to one embodiment of the present invention. Note that the light-emitting and receiving device 700 can be called a light-emitting device because it includes a light-emitting device, and can be called a light-receiving device because it includes a light-receiving device. Furthermore, since the light-emitting and receiving device 700 can be applied to a display portion of an electronic device or the like, it can also be called a display panel or a display device.

[0190] 2A includes a light-emitting / receiving device 700 including a light-emitting device 550B, a light-emitting device 550G, a light-emitting device 550R, and a light-receiving device 550PS formed on a functional layer 520 provided on a first substrate 510. The functional layer 520 includes driving circuits such as a gate driver and a source driver configured with multiple transistors, as well as wiring and the like that electrically connects these devices. These driving circuits are, for example, electrically connected to and can drive the light-emitting device 550B, the light-emitting device 550G, the light-emitting device 550R, and the light-receiving device 550PS. The light-emitting / receiving device 700 also includes an insulating layer 705 on the functional layer 520 and each device (the light-emitting device and the light-receiving device). The insulating layer 705 functions to bond the second substrate 770 to the functional layer 520.

[0191] Light-emitting device 550B, light-emitting device 550G, and light-emitting device 550R have the device structure described in Embodiment 2, and light-receiving device 550PS has the device structure described later in Embodiment 8. The configuration of EL layer 103 (see FIG. 1A ) differs between the devices, and for example, light-emitting layer 105B of EL layer 103B can emit blue light, light-emitting layer 105G of EL layer 103G can emit green light, and light-emitting layer 105R of EL layer 103G can emit red light.

[0192] In this embodiment, a case where each device (plurality of light-emitting devices and light-receiving devices) is formed separately will be described, but a part of the EL layer of the light-emitting device (hole injection layer, hole transport layer, and electron transport layer) and a part of the active layer of the light-receiving device (hole injection layer, hole transport layer, and electron transport layer) may be formed simultaneously from the same material in the manufacturing process. This will be described in detail in embodiment 8.

[0193] In this specification and the like, a structure in which the light-emitting layers of the light-emitting devices of each color (e.g., blue (B), green (G), and red (R)) and the light-receiving layers of the light-receiving devices are separately fabricated or separately painted may be referred to as an SBS (Side By Side) structure. In the light-receiving and light-emitting device 700 shown in FIG. 2A , the light-emitting device 550B, the light-emitting device 550G, the light-emitting device 550R, and the light-receiving device 550PS are arranged in this order, but one embodiment of the present invention is not limited to this configuration. For example, in the light-receiving and light-emitting device 700, these devices may be arranged in the order of the light-emitting device 550R, the light-emitting device 550G, the light-emitting device 550B, and the light-receiving device 550PS.

[0194] 2A , light-emitting device 550B includes electrode 551B, electrode 552, and EL layer 103B sandwiched between electrode 551B and electrode 552. Light-emitting device 550G includes electrode 551G, electrode 552, and EL layer 103G sandwiched between electrode 551G and electrode 552. Light-emitting device 550R includes electrode 551R, electrode 552, and EL layer 103R sandwiched between electrode 551R and electrode 552. EL layers (103B, 103G, 103R) have a stacked structure including multiple layers with different functions, including light-emitting layers (105B, 105G, 105R). The specific configuration of each layer of the light-emitting device is as described in Embodiment 2.

[0195] 2A , light-receiving device 550PS has electrode 551PS, electrode 552, and light-receiving layer 103PS sandwiched between electrode 551PS and electrode 552. Light-receiving layer 103PS has a layered structure made up of multiple layers with different functions, including active layer 105PS. The specific configuration of the light-receiving device is as shown in embodiment 8.

[0196] 2A illustrates a case in which the EL layer 103B has a hole injection / transport layer 104B, a light-emitting layer 105B, an electron transport layer 108B, and an electron injection layer 109; the EL layer 103G has a hole injection / transport layer 104G, a light-emitting layer 105G, an electron transport layer 108G, and an electron injection layer 109; the EL layer 103R has a hole injection / transport layer 104R, a light-emitting layer 105R, an electron transport layer 108R, and an electron injection layer 109; and the light-receiving layer 103PS has a hole injection / transport layer 104PS, an active layer 105PS, an electron transport layer 108PS, and an electron injection layer 109; however, the present invention is not limited to this.

[0197] The electron transport layers (108B, 108G, 108R, 108PS) may have a function of blocking holes that move from the anode side through the light-emitting layers (105B, 105G, 105R) and the active layer 105PS of the light-receiving device to the cathode side. The electron injection layer 109 may have a laminated structure formed of a part or all of different materials.

[0198] 2A , an insulating layer 107 may be formed on the side surfaces (or edges) of the hole injection / transport layers (104B, 104G, 104R), the light-emitting layers (105B, 105G, 105R), and the electron transport layers (108B, 108G, 108R) of the EL layers (103B, 103G, 103R), and on the side surfaces (or edges) of the hole injection / transport layer 104PS, the active layer 105PS, and the electron transport layer 108PS of the light-receiving layer 103PS. The insulating layer 107 is formed in contact with the side surfaces (or edges) of the EL layers (103B, 103G, 103R) and the light-receiving layer 103PS. This prevents oxygen, moisture, or their constituent elements from penetrating into the EL layers (103B, 103G, 103R) and the light-receiving layer 103PS from their side surfaces. The insulating layer 107 can be formed using, for example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, or silicon nitride oxide. The insulating layer 107 may also be formed by stacking the above-mentioned materials. The insulating layer 107 can be formed by sputtering, CVD, MBE, PLD, ALD, or other methods, but ALD is preferred due to its excellent coverage. The insulating layer 107 has a structure that continuously covers part of the EL layers (103B, 103G, and 103R) of adjacent light-emitting devices or part of the side surfaces (or ends) of the light-receiving layer 103PS of the light-receiving device. For example, in FIG. 2A , part of the EL layer 103B of the light-emitting device 550B and part of the side surfaces of the EL layer 103G of the light-emitting device 550G are covered by the insulating layer 107. In addition, in the region covered with the insulating layer 107, a partition wall 528 made of an insulating material may be formed as shown in FIG. 2A.

[0199] 2A, the electron injection layer 109 and the electrode 552 are layers (common layers) common to the devices (550B, 550G, 550R, and 550PS). The electron injection layer 109 may have a stacked structure of two or more layers (for example, a stack of layers with different electrical resistances).

[0200] Partition walls 528 are provided between the electrodes (551B, 551G, 551R, 551PS), parts of the EL layers (103B, 103G, 103R), and parts of the light-receiving layer 103PS. As shown in Fig. 2A, the electrodes (551B, 551G, 551R, 551PS), parts of the EL layers (103B, 103G, 103R), and parts of the light-receiving layer 103PS of each device are in contact with the partition walls 528 at their sides (or ends) via the insulating layer 107.

[0201] In each EL layer and light-receiving layer, the hole injection layer included in the hole transport region located between the anode and the light-emitting layer and between the anode and the active layer often has high conductivity, and therefore, if it is formed as a layer common to adjacent light-emitting devices, it may cause crosstalk. Therefore, by providing a partition wall 528 made of an insulating material between each EL layer and light-receiving layer as shown in this configuration example, it is possible to suppress the occurrence of crosstalk between adjacent devices.

[0202] Furthermore, in the manufacturing method described in this embodiment, the side surfaces (or edges) of the EL layer and the light-receiving layer are exposed during the patterning process. Therefore, the EL layer and the light-receiving layer are likely to deteriorate due to the intrusion of oxygen, water, and the like from the side surfaces (or edges) of the EL layer and the light-receiving layer. Therefore, by providing the partition 528, it is possible to suppress the deterioration of the EL layer and the light-receiving layer during the manufacturing process.

[0203] Furthermore, providing the partition 528 can also flatten recesses formed between adjacent devices. Flattening the recesses can prevent disconnection of the electrodes 552 formed on each EL layer and light-receiving layer. Examples of insulating materials used to form the partition 528 include organic materials such as acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimideamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenolic resin, and precursors of these resins. Organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, and alcohol-soluble polyamide resin may also be used. Photosensitive resins such as photoresists can also be used. The photosensitive resin can be a positive-type material or a negative-type material.

[0204] By using a photosensitive resin, the partition wall 528 can be formed only by exposure and development processes. Alternatively, the partition wall 528 may be formed using a negative photosensitive resin (e.g., a resist material). When an insulating layer containing an organic material is used for the partition wall 528, it is preferable to use a material that absorbs visible light. Using a material that absorbs visible light for the partition wall 528 allows the partition wall 528 to absorb light emitted from the EL layer, thereby suppressing light (stray light) that may leak into the adjacent EL layer and light-receiving layer. Therefore, a display panel with high display quality can be provided.

[0205] The difference in height between the upper surface of the partition wall 528 and the upper surface of any one of the EL layers (103B, 103G, 103R) and the light-receiving layer 103PS is preferably, for example, 0.5 times or less, more preferably 0.3 times or less, the thickness of the partition wall 528. For example, the partition wall 528 may be provided so that the upper surface of any one of the EL layers 103B, 103G, 103R, and the light-receiving layer 103PS is higher than the upper surface of the partition wall 528. For example, the partition wall 528 may be provided so that the upper surface of the partition wall 528 is higher than the upper surfaces of the EL layers 103B, 103G, 103R, and the light-receiving layer 103PS.

[0206] In a high-resolution light-receiving and light-emitting device (display panel) having a resolution of more than 1000 ppi, if electrical conduction is found between the EL layer 103B, the EL layer 103G, the EL layer 103R, and the light-receiving layer 103PS, crosstalk occurs, narrowing the color gamut that can be displayed by the light-receiving and light-emitting device. By providing the partition 528 in a high-resolution display panel having a resolution of more than 1000 ppi, preferably a high-resolution display panel having a resolution of more than 2000 ppi, and more preferably an ultra-high-resolution display panel having a resolution of more than 5000 ppi, a display panel that can display vivid colors can be provided.

[0207] 2B and 2C are schematic top views of the light emitting and receiving device 700 corresponding to the dashed line Ya-Yb in the cross-sectional view of FIG. 2A. That is, the light emitting devices (550B, 550G, 550R) are arranged in a matrix. FIG. 2B shows a so-called stripe arrangement in which light emitting devices of the same color are arranged in the X direction. FIG. 2C shows a configuration in which light emitting devices of the same color are arranged in the X direction, but with a pattern formed for each pixel. The arrangement of the light emitting devices is not limited to this; other arrangements, such as a delta arrangement or a zigzag arrangement, may also be used, and a pentile arrangement or a diamond arrangement may also be used.

[0208] In addition, since pattern formation is performed using photolithography in the separation process of each EL layer (103B, 103G, 103R) and the light-receiving layer 103PS, a high-resolution light-receiving and light-emitting device (display panel) can be manufactured. Furthermore, the ends (sides) of each layer of the EL layer processed by pattern formation using photolithography have a shape that has approximately the same surface (or is located on approximately the same plane). Furthermore, the side (end) of each layer of the light-receiving layer processed by pattern formation using photolithography has a shape that has approximately the same surface (or is located on approximately the same plane). Furthermore, in this case, the width (SE) of the gap 580 between each EL layer and the light-receiving layer is preferably 5 μm or less, and more preferably 1 μm or less.

[0209] In the EL layer, the hole injection layer included in the hole transport region located between the anode and the light-emitting layer, in particular, often has high conductivity, and therefore, if it is formed as a layer common to adjacent light-emitting devices, it may cause crosstalk. Therefore, by separating the EL layer by pattern formation using photolithography as shown in this configuration example, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0210] 2B and 2C. Fig. 2D shows a connection portion 130 where connection electrode 551C and electrode 552 are electrically connected. In connection portion 130, electrode 552 is provided in contact with connection electrode 551C. In addition, partition wall 528 is provided to cover the end of connection electrode 551C.

[0211] 3A, an electrode 551B, an electrode 551G, an electrode 551R, and an electrode 551PS are formed. For example, a conductive film is formed on the functional layer 520 formed on the first substrate 510, and processed into a predetermined shape by photolithography.

[0212] The conductive film can be formed by sputtering, chemical vapor deposition (CVD), molecular beam epitaxy (MBE), vacuum evaporation, pulsed laser deposition (PLD), atomic layer deposition (ALD), or the like. CVD methods include plasma enhanced chemical vapor deposition (PECVD) and thermal CVD. One type of thermal CVD method is metal organic chemical vapor deposition (MOCVD).

[0213] In addition to the photolithography method described above, the conductive film may be processed by a nanoimprint method, a sandblasting method, a lift-off method, etc. Alternatively, an island-shaped thin film may be directly formed by a film formation method using a shielding mask such as a metal mask.

[0214] There are two typical photolithography methods. One is a method in which a resist mask is formed on a thin film to be processed, the thin film is processed by etching or the like, and the resist mask is then removed. The other is a method in which a photosensitive thin film is formed, and then the thin film is processed into a desired shape by exposure and development. Note that the former method includes heat treatment steps such as pre-applied bake (PAB) after resist application and post-exposure bake (PEB) after exposure. In one embodiment of the present invention, lithography is used not only for processing a conductive film but also for processing a thin film (a film made of an organic compound or a film partially containing an organic compound) used to form an EL layer.

[0215] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these. Other light sources that can be used include ultraviolet light, KrF laser light, ArF laser light, etc. Exposure can also be performed by immersion exposure technology. Extreme ultraviolet (EUV) light or X-rays can also be used as the light used for exposure. An electron beam can also be used instead of light used for exposure. Extreme ultraviolet light, X-rays, or an electron beam are preferred because they enable extremely fine processing. When exposure is performed by scanning a beam such as an electron beam, a photomask is not required.

[0216] For etching the thin film using a resist mask, dry etching, wet etching, sandblasting, or the like can be used.

[0217] Next, as shown in FIG. 3B , a hole injection / transport layer 104B, a light-emitting layer 105B, and an electron transport layer 108B are formed on the electrodes 551B, 551G, 551R, and 551PS. The hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B can be formed by, for example, vacuum deposition. Furthermore, a sacrificial layer 110B is formed on the electron transport layer 108B. The materials described in Embodiments 1 and 2 can be used to form the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B.

[0218] It is preferable to use a film for the sacrificial layer 110B that is highly resistant to the etching processes of the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B, i.e., a film with a large etching selectivity. The sacrificial layer 110B preferably has a stacked structure of a first sacrificial layer and a second sacrificial layer with different etching selectivity. The sacrificial layer 110B may be a film that can be removed by wet etching, which causes minimal damage to the EL layer 103B. Oxalic acid or the like can be used as an etching material for wet etching. In this specification and the like, the sacrificial layer may also be referred to as a mask layer.

[0219] The sacrificial layer 110B may be, for example, a metal film, an alloy film, a metal oxide film, a semiconductor film, an inorganic insulating film, etc. The sacrificial layer 110B may be formed by various film formation methods such as a sputtering method, a vapor deposition method, a CVD method, an ALD method, etc.

[0220] The sacrificial layer 110B may be made of a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, or tantalum, or an alloy material containing such a metal material. In particular, it is preferable to use a low-melting-point material such as aluminum or silver.

[0221] The sacrificial layer 110B may be made of a metal oxide such as indium gallium zinc oxide (In-Ga-Zn oxide, also referred to as IGZO). Other examples include indium oxide, indium zinc oxide (In-Zn oxide), indium tin oxide (In-Sn oxide), indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), and indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide). Alternatively, silicon-containing indium tin oxide may be used.

[0222] The present invention can also be applied to a case where, instead of the gallium, an element M (wherein M is one or more elements selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) is used. In particular, it is preferable that M is one or more elements selected from gallium, aluminum, and yttrium.

[0223] The sacrificial layer 110B may be made of an inorganic insulating material such as aluminum oxide, hafnium oxide, or silicon oxide.

[0224] Furthermore, the sacrificial layer 110B is preferably made of a material that can be dissolved in a chemically stable solvent, as compared with the electron transport layer 108B located at the top. Materials that dissolve in water or alcohol are particularly suitable for use in the sacrificial layer 110B. When forming the sacrificial layer 110B, it is preferable to apply the sacrificial layer 110B dissolved in a solvent such as water or alcohol using a wet film formation method, and then perform a heat treatment to evaporate the solvent. In this case, performing the heat treatment under a reduced pressure atmosphere is preferable because it allows the solvent to be removed at a low temperature and in a short time, thereby reducing thermal damage to the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B.

[0225] When the sacrificial layer 110B has a laminated structure, a layer made of the above-mentioned material can be used as a first sacrificial layer, and a second sacrificial layer can be formed thereon to form a laminated structure.

[0226] In this case, the second sacrificial layer is a film used as a hard mask when etching the first sacrificial layer. Furthermore, the first sacrificial layer is exposed when the second sacrificial layer is processed. Therefore, a combination of films with a high etching selectivity is selected for the first sacrificial layer and the second sacrificial layer. Therefore, a film that can be used for the second sacrificial layer can be selected depending on the etching conditions for the first sacrificial layer and the second sacrificial layer.

[0227] For example, when dry etching using a gas containing fluorine (also called a fluorine-based gas) is used to etch the second sacrificial layer, silicon, silicon nitride, silicon oxide, tungsten, titanium, molybdenum, tantalum, tantalum nitride, an alloy containing molybdenum and niobium, an alloy containing molybdenum and tungsten, etc. can be used for the second sacrificial layer. Here, metal oxide films such as IGZO and ITO can be used as films that can have a large etching selectivity (i.e., can slow the etching rate) compared to dry etching using the fluorine-based gas, and these can be used for the first sacrificial layer.

[0228] However, the second sacrificial layer is not limited to this, and can be selected from various materials depending on the etching conditions of the first sacrificial layer and the second sacrificial layer, for example, from among the films that can be used for the first sacrificial layer.

[0229] The second sacrificial layer may be, for example, a nitride film, such as silicon nitride, aluminum nitride, hafnium nitride, titanium nitride, tantalum nitride, tungsten nitride, gallium nitride, or germanium nitride.

[0230] Alternatively, an oxide film can be used as the second sacrificial layer. Typically, an oxide film or an oxynitride film such as silicon oxide, silicon oxynitride, aluminum oxide, aluminum oxynitride, hafnium oxide, or hafnium oxynitride can be used.

[0231] Next, as shown in FIG. 3C , a resist is applied to the sacrificial layer 110B, and the resist is formed into a desired shape (resist mask: RES) using photolithography. When performing this method, heat treatment processes such as pre-applied bake (PAB) after resist application and post-exposure bake (PEB) after exposure are performed. For example, the PAB temperature is approximately 100° C., and the PEB temperature is approximately 120° C. Therefore, the light-emitting device must be able to withstand these processing temperatures.

[0232] Next, using the obtained resist mask RES, a portion of the sacrificial layer 110B that is not covered by the resist mask RES is removed by etching. After the resist mask RES is removed, the portions of the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B that are not covered by the sacrificial layer 110B are removed by etching, and the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B are processed into a shape that has a side surface on the electrode 551B (or has an exposed side surface) or into a strip-like shape extending in a direction intersecting with the plane of the page. Dry etching is preferred for this etching. When the sacrificial layer 110B has a laminated structure of the first and second sacrificial layers, a portion of the second sacrificial layer may be etched using the resist mask RES, and then the resist mask RES may be removed. Then, a portion of the first sacrificial layer may be etched using the second sacrificial layer as a mask, thereby processing the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B into the predetermined shapes. These etching processes result in the shape shown in FIG. 4A .

[0233] 4B , a hole injection / transport layer 104G, a light-emitting layer 105G, and an electron transport layer 108G are formed on the sacrificial layer 110B, the electrode 551G, the electrode 551R, and the electrode 551PS. The materials used to form the hole injection / transport layer 104G, the light-emitting layer 105G, and the electron transport layer 108G can be the same as those described in Embodiments 1 and 2. The hole injection / transport layer 104G, the light-emitting layer 105G, and the electron transport layer 108G can be formed by vacuum deposition, for example.

[0234] 4C , a sacrificial layer 110G is formed on the electron transport layer 108G, a resist is applied to the sacrificial layer 110G, and the resist is formed into a desired shape (resist mask: RES) using photolithography. The portion of the sacrificial layer 110G that is not covered by the resulting resist mask is removed by etching. After the resist mask is removed, the portions of the hole injection / transport layer 104G, the light-emitting layer 105G, and the electron transport layer 108G that are not covered by the sacrificial layer 110G are removed by etching. The hole injection / transport layer 104G, the light-emitting layer 105G, and the electron transport layer 108G are then processed into a shape that has a side surface on the electrode 551G (or has an exposed side surface) or into a strip-like shape extending in a direction intersecting the plane of the page. Dry etching is preferred for this etching. Furthermore, the sacrificial layer 110G can be made of the same material as the sacrificial layer 110B. When the sacrificial layer 110G has a laminated structure of the first and second sacrificial layers, a portion of the second sacrificial layer may be etched using a resist mask RES, and then the resist mask RES may be removed. Then, a portion of the first sacrificial layer may be etched using the second sacrificial layer as a mask, thereby processing the hole injection / transport layer 104G, the light-emitting layer 105G, and the electron transport layer 108G into the predetermined shapes. These etching processes result in the shape shown in FIG. 5A .

[0235] 5B , a hole injection / transport layer 104R, a light-emitting layer 105R, and an electron transport layer 108R are formed on the sacrificial layer 110B, the sacrificial layer 110G, the electrode 551R, and the electrode 551PS. The materials used to form the hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R can be the same as those described in Embodiments 1 and 2. The hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R can be formed by vacuum deposition, for example.

[0236] 5C , a sacrificial layer 110R is formed on the electron transport layer 108R, a resist is applied to the sacrificial layer 110R, and the resist is formed into a desired shape (resist mask: RES) using photolithography. The portion of the sacrificial layer 110R that is not covered by the resulting resist mask RES is removed by etching. After the resist mask RES is removed, the portions of the hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R that are not covered by the sacrificial layer 110R are removed by etching. This allows the hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R to be shaped so that they have sides (or have exposed sides) on the electrode 551R or strip-like shapes extending in a direction intersecting the plane of the page. Dry etching is preferred for this etching. The sacrificial layer 110R can be made of the same material as the sacrificial layer 110B. When the sacrificial layer 110R has a laminated structure of the first and second sacrificial layers, the second sacrificial layer may be partially etched using the resist mask RES, and then the resist mask RES may be removed. Then, the first sacrificial layer may be partially etched using the second sacrificial layer as a mask, thereby processing the hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R into the predetermined shapes. These etching processes result in the shape shown in FIG. 6A .

[0237] Next, as shown in FIG. 6B , a hole injection / transport layer 104PS, an active layer 105PS, and an electron transport layer 108PS are formed on the sacrificial layer 110B, the sacrificial layer 110G, the sacrificial layer 110R, and the electrode 551PS. The hole injection / transport layer 104PS can be formed from materials such as those described in Embodiment 2 for the hole injection layer and the hole transport layer of the light-emitting device. The active layer 105PS can be formed from materials such as those described in Embodiment 8. The electron transport layer 108PS can be formed from materials such as those described in Embodiment 2 for the electron transport layer and the electron injection layer. The hole injection / transport layer 104PS, the active layer 105PS, and the electron transport layer 108PS can be formed, for example, by vacuum deposition.

[0238] 6C , a sacrificial layer 110PS is formed on the electron transport layer 108PS, a resist is applied to the sacrificial layer 110PS, and the resist is formed into a desired shape (resist mask: RES) using photolithography. The portion of the sacrificial layer 110PS that is not covered by the resulting resist mask RES is removed by etching. After the resist mask RES is removed, the hole injection / transport layer 104PS, the active layer 105PS, and the electron transport layer 108PS that are not covered by the sacrificial layer are removed by etching. The hole injection / transport layer 104PS, the active layer 105PS, and the electron transport layer 108PS are then shaped to have a side surface on the electrode 551PS (or an exposed side surface) or a strip-like shape extending in a direction intersecting the plane of the page. Dry etching is preferred for this etching. The sacrificial layer 110PS may be made of the same material as the sacrificial layer 110B. When the sacrificial layer 110PS has a laminated structure of the first and second sacrificial layers, the second sacrificial layer may be partially etched using the resist mask RES, and then the resist mask RES may be removed. Then, the first sacrificial layer may be partially etched using the second sacrificial layer as a mask, thereby processing the hole injection / transport layer 104PS, the active layer 105PS, and the electron transport layer 108PS into the predetermined shapes. These etching processes result in the shape shown in FIG. 6D .

[0239] Next, as shown in FIG. 7A, an insulating layer 107 is formed on the sacrificial layers 110B, 110G, 110R, and 110PS.

[0240] The insulating layer 107 can be formed by, for example, ALD. In this case, as shown in FIG. 7A , the insulating layer 107 is formed in contact with the side surfaces (ends) of the hole injection / transport layers (104B, 104G, 104R), light-emitting layers (105B, 105G, 105R), and electron transport layers (108B, 108G, 108R) of the light-emitting devices, as well as the hole injection / transport layer 104PS, active layer 105PS, and electron transport layer 108PS of the light-receiving device. This prevents oxygen, moisture, or their constituent elements from penetrating into the interior from the side surfaces. Examples of materials that can be used for the insulating layer 107 include aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, and silicon nitride oxide.

[0241] 7B, a resin film 528a is formed on the insulating layer 107. For example, a negative photosensitive resin or a positive photosensitive resin can be used as the resin film 528a.

[0242] Next, as shown in FIG. 7C, a portion of the resin film 528a, a portion of the insulating layer 107, and the sacrificial layers (110B, 110G, 110R, 110PS) are removed to expose the upper surfaces of the electron transport layers (108B, 108G, 108R, 108PS).

[0243] 7D , heat treatment is performed to curve the upper end of the resin film 528a, thereby forming the partition wall 528. By curved-shaping the upper end of the partition wall 528, it is possible to improve the coverage of the electron injection layer 109 to be formed later. For example, when a positive photosensitive acrylic resin is used as the resin film 528a, it is preferable to provide the upper end of the partition wall 528 with a curved surface having a radius of curvature (0.2 μm to 3 μm).

[0244] Next, the electron injection layer 109 is formed over the insulating layer 107, the electron transport layers (108B, 108G, 108R, and 108PS), and the partition wall 528. The electron injection layer 109 can be formed using the materials described in Embodiment 2. Note that the electron injection layer 109 is formed by, for example, a vacuum evaporation method.

[0245] 8A, an electrode 552 is formed on the electron injection layer 109. The electrode 552 is formed by, for example, vacuum deposition.

[0246] Through the above steps, EL layers 103B, 103G, 103R, and light-receiving layer 103PS in light-emitting devices 550B, 550G, and 550R, and light-receiving device 550PS can be separated and processed, respectively.

[0247] In addition, since pattern formation is performed using photolithography in the separation processing of these EL layers (EL layer 103B, EL layer 103G, EL layer 103R) and light-receiving layer 103PS, a high-definition light-receiving and light-emitting device (display panel) can be manufactured. Furthermore, the ends (side surfaces) of each layer of the EL layer processed by pattern formation using photolithography have a shape that is approximately the same surface (or located on approximately the same plane). Furthermore, the side surfaces (end surfaces) of each layer of the light-receiving layer processed by pattern formation using photolithography have a shape that is approximately the same surface (or located on approximately the same plane).

[0248] Furthermore, the hole injection / transport layers (104B, 104G, and 104R) in the EL layer and the hole injection / transport layer 104PS in the light-receiving layer often have high electrical conductivity, which can cause crosstalk if they are formed as layers common to adjacent light-emitting devices. Therefore, by separating the EL layer through pattern formation using photolithography, as shown in this configuration example, it is possible to suppress crosstalk between adjacent light-emitting devices and light-receiving devices.

[0249] The hole injection / transport layers (104B, 104G, 104R), light-emitting layers (105B, 105G, 105R), and electron transport layers (108B, 108G, 108R) included in each EL layer (103B, 103G, 103R) of each light-emitting device in this configuration, and the hole injection / transport layer 104PS, active layer 105PS, and electron transport layer 108PS included in the light-receiving layer 103PS of the light-receiving device, are patterned using photolithography during separation processing, so that the edges (side surfaces) of the processed EL layers have shapes that are approximately flush with each other (or located on approximately the same plane). Furthermore, the edges (end surfaces) of each layer of the light-receiving layer processed by patterning using photolithography also have shapes that are approximately flush with each other (or located on approximately the same plane).

[0250] Furthermore, the hole injection / transport layers (104B, 104G, 104R), light-emitting layers (105B, 105G, 105R), and electron transport layers (108B, 108G, 108R) included in each EL layer (EL layer 103B, EL layer 103G, and EL layer 103R) of each light-emitting device, and the hole injection / transport layer 104PS, active layer 105PS, and electron transport layer 108PS included in the absorption layer 103PS of the light-receiving device are patterned using photolithography in the separation process, so that each processed end (side) has a gap 580 between adjacent light-emitting devices. Note that in Figure 8A, when the distance between the EL layers or absorption layers of adjacent devices is represented by SE, the smaller the distance SE, the higher the aperture ratio and the higher the definition. On the other hand, the larger the distance SE, the more tolerant the influence of manufacturing process variations between adjacent devices can be, and therefore the manufacturing yield can be increased. Because the light-emitting devices and light-receiving devices manufactured according to this specification are suitable for miniaturization processes, the distance SE between the EL layers or light-receiving layers of adjacent devices can be set to 0.5 μm or more and 5 μm or less, preferably 1 μm or more and 3 μm or less, more preferably 1 μm or more and 2.5 μm or less, and even more preferably 1 μm or more and 2 μm or less. Typically, the distance SE is preferably 1 μm or more and 2 μm or less (e.g., 1.5 μm or thereabouts).

[0251] In this specification and the like, a device fabricated using a metal mask or an FMM (fine metal mask, high-resolution metal mask) may be referred to as a device with an MM (metal mask) structure. In addition, in this specification and the like, a device fabricated without using a metal mask or an FMM may be referred to as a device with an MML (metal maskless) structure. Because an MML structure light-emitting and receiving device is fabricated without using a metal mask, it has a higher degree of design freedom in terms of pixel arrangement, pixel shape, and the like than an FMM structure light-emitting and receiving device or an MM structure.

[0252] The island-shaped EL layer in the MML-structure light-emitting / receiving device is not formed by a metal mask pattern, but is formed by processing the EL layer after it has been formed. This makes it possible to realize a light-emitting / receiving device with higher resolution or a higher aperture ratio than ever before. Furthermore, since the EL layer can be made separately for each color, a light-emitting / receiving device with extremely vivid, high-contrast, and high display quality can be realized. Furthermore, providing a sacrificial layer on the EL layer reduces damage to the EL layer during the manufacturing process, thereby improving the reliability of the light-emitting device.

[0253] In the light-emitting devices 550B, 550G, and 550R shown in Figures 2A and 8A, the width of the EL layers (103B, 103G, and 103R) is approximately equal to the width of the electrodes (551B, 551G, and 551R), and in the light-receiving device 550PS, the width of the light-receiving layer 103PS is approximately equal to the width of the electrode 551PS, but one embodiment of the present invention is not limited to this.

[0254] In the light-emitting devices 550B, 550G, and 550R, the width of the EL layers (103B, 103G, and 103R) may be smaller than the width of the electrodes (551B, 551G, and 551R). In the light-receiving device 550PS, the width of the light-receiving layer 103PS may be smaller than the width of the electrode 551PS. Figure 8B shows an example in which the width of the EL layer 103B in the light-emitting device 550B is smaller than the width of the electrode 551B.

[0255] In addition, in light-emitting devices 550B, 550G, and 550R, the width of the EL layers (103B, 103G, and 103R) may be larger than the width of the electrodes (551B, 551G, and 551R). In light-receiving device 550PS, the width of light-receiving layer 103PS may be larger than the width of electrode 551PS. Figure 8C shows an example in which the width of EL layer 103R is larger than the width of electrode 551R in light-emitting device 550R.

[0256] The light-receiving and light-emitting device described in this embodiment is a device having both a light-emitting device and a light-receiving device, and can also be called a light-emitting device including a light-receiving device or a light-receiving device including a light-emitting device. Furthermore, among the configurations of the light-receiving and light-emitting devices described in this embodiment, a device that does not have a light-receiving device can also be called a light-emitting device. Furthermore, among the configurations of the light-receiving and light-emitting devices described in this embodiment, a device that does not have a light-emitting device can also be called a light-receiving device.

[0257] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0258] (Embodiment 4) In this embodiment, a device 720 will be described with reference to FIGS. 9 to 11. Note that the device 720 shown in FIGS. 9 to 11 is a light-emitting device because it includes the light-emitting device described in Embodiment 2. However, the device 720 described in this embodiment can also be called a display panel or a display device because it can be applied to a display portion of an electronic device or the like. Furthermore, when the device uses the light-emitting device as a light source and includes a light-receiving device that can receive light from the light-emitting device, it can also be called a light-receiving / emitting device. Note that these light-emitting devices, display panels, display devices, and light-receiving / emitting devices have at least a light-emitting device.

[0259] Furthermore, the light-emitting device, display panel, display device, and light-emitting and receiving device of the present embodiment can be a high-resolution or large-sized light-emitting device, display panel, display device, and light-emitting and receiving device. Therefore, the light-emitting device, display panel, display device, and light-emitting and receiving device of the present embodiment can be used in the display portion of electronic devices having relatively large screens, such as television devices, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, smartphones, wristwatch-type terminals, tablet terminals, personal digital assistants, and sound reproducing devices.

[0260] FIG. 9A shows a top view of these devices (including a light-emitting device, a display panel, a display device, and a light-emitting and receiving device) 720 .

[0261] 9A , a device 720 has a configuration in which a substrate 710 and a substrate 711 are bonded together. The device 720 also has a display region 701, a circuit 704, wiring 706, and the like. The display region 701 has a plurality of pixels, and a pixel 703(i, j) shown in FIG. 9A has a pixel 703(i+1, j) adjacent to the pixel 703(i, j) as shown in FIG. 9B .

[0262] 9A , the device 720 includes an IC (integrated circuit) 712 provided on a substrate 710 by a chip-on-glass (COG) method, a chip-on-film (COF) method, or the like. For example, an IC having a scanning line driver circuit or a signal line driver circuit can be used as the IC 712. In FIG. 9A , an IC having a signal line driver circuit is used as the IC 712, and a scanning line driver circuit is used as the circuit 704.

[0263] The wiring 706 has a function of supplying signals and power to the display region 701 and the circuit 704. The signals and power are input to the wiring 706 from the outside through a flexible printed circuit (FPC) 713 or are input to the wiring 706 from an IC 712. Note that the device 720 may not include an IC. Alternatively, the IC may be mounted on the FPC by a COF method or the like.

[0264] FIG. 9B shows pixel 703(i,j) and pixel 703(i+1,j) in the display region 701. That is, pixel 703(i,j) can be configured to have multiple types of subpixels having light-emitting devices that emit different colors. Alternatively, in addition to the above, pixel 703(i,j) can be configured to include multiple subpixels having light-emitting devices that emit the same color. When a pixel has multiple types of subpixels having light-emitting devices that emit different colors, the pixel can be configured to have three types of subpixels. Examples of the three subpixels include subpixels of three colors: red (R), green (G), and blue (B), or subpixels of three colors: yellow (Y), cyan (C), and magenta (M). Alternatively, the pixel can be configured to have four types of subpixels. Examples of the four subpixels include subpixels of four colors: R, G, B, and white (W), or subpixels of four colors: R, G, B, and Y. Specifically, the pixel 703(i,j) can be configured with a sub-pixel 702B(i,j) that displays blue, a sub-pixel 702G(i,j) that displays green, and a sub-pixel 702R(i,j) that displays red.

[0265] Additionally, device 720 includes subpixels with light-receiving devices as well as subpixels with light-emitting devices.

[0266] 9C to 9E show examples of various layouts including a subpixel 702PS(i,j) having a light receiving device. The pixel arrangement shown in Fig. 9C is a stripe arrangement, while the pixel arrangement shown in Fig. 9D is a matrix arrangement. The pixel arrangement shown in Fig. 9E has a configuration in which three subpixels (subpixel R, subpixel G, and subpixel PS) are vertically arranged next to one subpixel (subpixel B).

[0267] 9F , a subpixel 702IR(i,j) that emits infrared light may be added to the above set to form pixel 703(i,j). The pixel arrangement shown in FIG. 9F has a configuration in which three vertically elongated subpixels G, B, and R are arranged horizontally, and below them, a subpixel PS and a horizontally elongated subpixel IR are arranged horizontally. Specifically, a subpixel 702IR(i,j) that emits light containing light having a wavelength of 650 nm or more and 1000 nm or less may be used for pixel 703(i,j). Although the wavelength of light detected by the subpixel 702PS(i,j) is not particularly limited, it is preferable that the light receiving device of the subpixel 702PS(i,j) is sensitive to light emitted by the light emitting device of the subpixel 702R(i,j), the subpixel 702G(i,j), the subpixel 702B(i,j), or the subpixel 702IR(i,j). For example, it is preferable to detect one or more of light in wavelength ranges such as blue, purple, blue-purple, green, yellow-green, yellow, orange, and red, and light in the infrared wavelength range.

[0268] 9B to 9F, various arrangements of the sub-pixels can be applied, such as a stripe arrangement, an S-stripe arrangement, a matrix arrangement, a delta arrangement, a Bayer arrangement, and a pentile arrangement.

[0269] Examples of the top surface shape of the sub-pixel include a triangle, a quadrangle (including a rectangle and a square), a polygon such as a pentagon, a polygon with rounded corners, an ellipse, a circle, etc. The top surface shape of the sub-pixel here corresponds to the top surface shape of the light-emitting region of the light-emitting device.

[0270] Furthermore, when a pixel has not only a light-emitting device but also a light-receiving device, the pixel has a light-receiving function, so that it is possible to detect contact or proximity of an object while displaying an image. For example, instead of displaying an image using all of the sub-pixels of the light-emitting device, some of the sub-pixels can emit light as a light source and the remaining sub-pixels can display an image.

[0271] It is preferable that the light-receiving area of ​​the subpixel 702PS(i,j) be smaller than the light-emitting area of ​​the other subpixels. The smaller the light-receiving area, the narrower the imaging range, which makes it possible to suppress blurring in the imaging result and improve resolution. Therefore, by using the subpixel 702PS(i,j), high-definition or high-resolution imaging can be performed. For example, the subpixel 702PS(i,j) can be used to capture images for personal authentication using fingerprints, palm prints, irises, pulse shapes (including vein shapes and arterial shapes), faces, etc.

[0272] The subpixel 702PS(i,j) can be used as a touch sensor (also called a direct touch sensor) or a near-touch sensor (also called a hover sensor, hover touch sensor, non-contact sensor, or touchless sensor). For example, the subpixel 702PS(i,j) preferably detects infrared light. This enables touch detection even in dark places.

[0273] Here, a touch sensor or near-touch sensor can detect the proximity or contact of an object (such as a finger, hand, or pen). A touch sensor can detect an object by direct contact between the light-emitting and receiving device and the object. A near-touch sensor can detect an object even if the object does not come into contact with the light-emitting and receiving device. For example, a configuration in which the light-emitting and receiving device can detect an object when the distance between the light-emitting and receiving device and the object is between 0.1 mm and 300 mm, preferably between 3 mm and 50 mm, is preferable. This configuration enables operation without the object directly touching the light-emitting and receiving device, in other words, operation of the light-emitting and receiving device in a non-contact (touchless) manner. This configuration reduces the risk of the light-emitting and receiving device becoming dirty or scratched, or enables operation of the light-emitting and receiving device without the object directly touching dirt (e.g., dust, bacteria, or viruses) attached to the display device.

[0274] In order to capture high-resolution images, it is preferable that the sub-pixels 702PS(i,j) are provided in all pixels of the light-emitting and receiving device. On the other hand, when used in a touch sensor or near-touch sensor, the sub-pixels 702PS(i,j) do not require high accuracy compared to when capturing images of fingerprints, etc., so they may be provided in only some of the pixels of the light-emitting and receiving device. By making the number of sub-pixels 702PS(i,j) in the light-emitting and receiving device smaller than the number of sub-pixels 702R(i,j), etc., the detection speed can be increased.

[0275] Next, an example of a pixel circuit of a subpixel having a light-emitting device will be described with reference to FIG. 10A . The pixel circuit 530 shown in FIG. 10A includes a light-emitting device (EL) 550, a transistor M15, a transistor M16, a transistor M17, and a capacitor C3. A light-emitting diode can be used as the light-emitting device 550. In particular, it is preferable to use the light-emitting device described in Embodiment 2 as the light-emitting device 550.

[0276] 10A , the gate of the transistor M15 is electrically connected to a wiring VG, one of the source or drain is electrically connected to a wiring VS, and the other of the source or drain is electrically connected to one electrode of the capacitor C3 and the gate of the transistor M16. One of the source or drain of the transistor M16 is electrically connected to a wiring V4, and the other is electrically connected to the anode of the light-emitting device 550 and one of the source or drain of the transistor M17. The gate of the transistor M17 is electrically connected to a wiring MS, and the other of the source or drain is electrically connected to a wiring OUT2. The cathode of the light-emitting device 550 is electrically connected to a wiring V5.

[0277] A constant potential is supplied to the wiring V4 and the wiring V5. The anode side of the light-emitting device 550 can be set to a high potential, and the cathode side can be set to a lower potential than the anode side. The transistor M15 is controlled by a signal supplied to the wiring VG and functions as a selection transistor for controlling the selection state of the pixel circuit 530. The transistor M16 also functions as a drive transistor that controls the current flowing through the light-emitting device 550 depending on the potential supplied to its gate. When the transistor M15 is in a conductive state, the potential supplied to the wiring VS is supplied to the gate of the transistor M16, and the light emission brightness of the light-emitting device 550 can be controlled depending on the potential. The transistor M17 is controlled by a signal supplied to the wiring MS and has the function of outputting the potential between the transistor M16 and the light-emitting device 550 to the outside via the wiring OUT2.

[0278] Note that it is preferable to use transistors using a metal oxide (oxide semiconductor) in a semiconductor layer in which a channel is formed for the transistors M15, M16, and M17 included in the pixel circuit 530 of FIG. 10A and the transistors M11, M12, M13, and M14 included in the pixel circuit 531 of FIG. 10B.

[0279] A transistor using a metal oxide, which has a wider band gap and a lower carrier density than silicon, can achieve an extremely small off-state current. Therefore, the small off-state current allows charge stored in a capacitor connected in series with the transistor to be held for a long period of time. Therefore, it is preferable to use a transistor including an oxide semiconductor for the transistor M11, the transistor M12, and the transistor M15, which are connected in series with the capacitor C2 or the capacitor C3. Furthermore, by using a transistor including an oxide semiconductor for other transistors as well, manufacturing costs can be reduced.

[0280] Alternatively, the transistors M11 to M17 may be transistors in which silicon is used as a semiconductor in which a channel is formed. In particular, using silicon with high crystallinity, such as single crystal silicon or polycrystalline silicon, is preferable because high field-effect mobility can be achieved and higher-speed operation is possible.

[0281] Alternatively, a structure may be used in which at least one of the transistors M11 to M17 includes an oxide semiconductor and the remaining transistors include silicon.

[0282] Next, an example of a pixel circuit of a sub-pixel having a light receiving device will be described with reference to Fig. 10B. The pixel circuit 531 shown in Fig. 10B includes a light receiving device (PD) 560, transistors M11, M12, M13, and M14, and a capacitance element C2. In this example, a photodiode is used as the light receiving device (PD) 560.

[0283] 10B , the anode of the light-receiving device (PD) 560 is electrically connected to the wiring V1, and the cathode is electrically connected to one of the source and drain of the transistor M11. The gate of the transistor M11 is electrically connected to the wiring TX, and the other of the source and drain is electrically connected to one electrode of the capacitor C2, one of the source and drain of the transistor M12, and the gate of the transistor M13. The gate of the transistor M12 is electrically connected to the wiring RE1, and the other of the source and drain is electrically connected to the wiring V2. The source and drain of the transistor M13 is electrically connected to the wiring V3, and the other of the source and drain is electrically connected to one of the source and drain of the transistor M14. The gate of the transistor M14 is electrically connected to the wiring SE1, and the other of the source and drain is electrically connected to the wiring OUT1.

[0284] A constant potential is supplied to the wiring V1, the wiring V2, and the wiring V3. When the light-receiving device (PD) 560 is driven with a reverse bias, a potential higher than the potential of the wiring V1 is supplied to the wiring V2. The transistor M12 is controlled by a signal supplied to the wiring RE1 and has a function of resetting the potential of a node connected to the gate of the transistor M13 to the potential supplied to the wiring V2. The transistor M11 is controlled by a signal supplied to the wiring TX and has a function of controlling the timing at which the potential of the node changes depending on the current flowing through the light-receiving device (PD) 560. The transistor M13 functions as an amplifying transistor that outputs according to the potential of the node. The transistor M14 is controlled by a signal supplied to the wiring SE1 and functions as a selection transistor for reading out an output according to the potential of the node to an external circuit connected to the wiring OUT1.

[0285] Note that although the transistors are depicted as n-channel transistors in FIGS. 10A and 10B, p-channel transistors can also be used.

[0286] The transistors included in the pixel circuit 530 and the transistors included in the pixel circuit 531 are preferably formed side by side on the same substrate. In particular, it is preferable that the transistors included in the pixel circuit 530 and the transistors included in the pixel circuit 531 are mixed and periodically arranged in one region.

[0287] It is also preferable to provide one or more layers having one or both of a transistor and a capacitor element at a position overlapping the light receiving device (PD) 560 or the light emitting device (EL) 550. This can reduce the effective area occupied by each pixel circuit, thereby realizing a high-definition light receiving section or display section.

[0288] 10C shows an example of a specific structure of a transistor that can be applied to the pixel circuits described with reference to FIG. 10A and FIG. 10B. Note that a bottom-gate transistor, a top-gate transistor, or the like can be used as the transistor as appropriate.

[0289] 10C includes a semiconductor film 508, a conductive film 504, an insulating film 506, a conductive film 512A, and a conductive film 512B. The transistor is formed over, for example, an insulating film 501C. The transistor also includes an insulating film 516 (insulating films 516A and 516B) and an insulating film 518.

[0290] The semiconductor film 508 has a region 508A electrically connected to the conductive film 512A and a region 508B electrically connected to the conductive film 512B. The semiconductor film 508 has a region 508C between the region 508A and the region 508B.

[0291] The conductive film 504 has a region overlapping with the region 508C, and functions as a gate electrode.

[0292] The insulating film 506 has a region sandwiched between the semiconductor film 508 and the conductive film 504. The insulating film 506 functions as a first gate insulating film.

[0293] The conductive film 512A has a function as either a source electrode or a drain electrode, and the conductive film 512B has the other function as either a source electrode or a drain electrode.

[0294] The conductive film 524 can also be used for a transistor. The conductive film 524 has a region where the semiconductor film 508 is sandwiched between the conductive film 524 and the conductive film 504. The conductive film 524 functions as a second gate electrode. The insulating film 501D is sandwiched between the semiconductor film 508 and the conductive film 524 and functions as a second gate insulating film.

[0295] The insulating film 516 functions as, for example, a protective film that covers the semiconductor film 508. Specific examples of the insulating film 516 that can be used include a silicon oxide film, a silicon oxynitride film, a silicon nitride oxide film, a silicon nitride film, an aluminum oxide film, a hafnium oxide film, an yttrium oxide film, a zirconium oxide film, a gallium oxide film, a tantalum oxide film, a magnesium oxide film, a lanthanum oxide film, a cerium oxide film, and a neodymium oxide film.

[0296] The insulating film 518 is preferably formed using a material that has a function of suppressing diffusion of, for example, oxygen, hydrogen, water, an alkali metal, an alkaline earth metal, or the like. Specifically, for example, silicon nitride, silicon oxynitride, aluminum nitride, aluminum oxynitride, or the like can be used for the insulating film 518. Furthermore, the number of nitrogen atoms contained in silicon oxynitride and aluminum oxynitride is preferably larger than the number of oxygen atoms contained therein.

[0297] Note that a semiconductor film to be used for a transistor in a pixel circuit can be formed in the same process as a semiconductor film to be used for a transistor in a driver circuit. For example, a semiconductor film having the same composition as that of a semiconductor film to be used for a transistor in a pixel circuit can be used for the driver circuit.

[0298] The semiconductor film 508 preferably contains, for example, indium, M (M is one or more elements selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, M is preferably one or more elements selected from aluminum, gallium, yttrium, and tin.

[0299] In particular, it is preferable to use an oxide containing indium (In), gallium (Ga), and zinc (Zn) (also referred to as IGZO) for the semiconductor film 508. Alternatively, it is preferable to use an oxide containing indium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium, gallium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium (In), aluminum (Al), and zinc (Zn) (also referred to as IAZO). Alternatively, it is preferable to use an oxide containing indium (In), aluminum (Al), gallium (Ga), and zinc (Zn) (also referred to as IAGZO).

[0300] When the semiconductor film is an In-M-Zn oxide, the atomic ratio of In in the In-M-Zn oxide is preferably equal to or greater than the atomic ratio of M. The atomic ratio of metal elements in such an In-M-Zn oxide may be In:M:Zn=1:1:1 or a composition thereof in the vicinity thereof, In:M:Zn=1:1:1.2 or a composition thereof in the vicinity thereof, In:M:Zn=1:3:2 or a composition thereof in the vicinity thereof, In:M:Zn=1:3:4 or a composition thereof in the vicinity thereof, In:M:Zn=2:1:3 or a composition thereof in the vicinity thereof, In:M:Zn=3:1:2 or a composition thereof, or In:M:Zn=4:2:3. or a composition in the vicinity thereof, In:M:Zn = 4:2:4.1 or a composition in the vicinity thereof, In:M:Zn = 5:1:3 or a composition in the vicinity thereof, In:M:Zn = 5:1:6 or a composition in the vicinity thereof, In:M:Zn = 5:1:7 or a composition in the vicinity thereof, In:M:Zn = 5:1:8 or a composition in the vicinity thereof, In:M:Zn = 6:1:6 or a composition in the vicinity thereof, In:M:Zn = 5:2:5 or a composition in the vicinity thereof, etc. Note that a composition in the vicinity thereof includes a range of ±30% of the desired atomic ratio.

[0301] For example, when describing a composition having an atomic ratio of In:Ga:Zn=4:2:3 or thereabout, this includes a case where, when the atomic ratio of In is 4, the atomic ratio of Ga is 1 or more and 3 or less, and the atomic ratio of Zn is 2 or more and 4 or less. Furthermore, when describing a composition having an atomic ratio of In:Ga:Zn=5:1:6 or thereabout, this includes a case where, when the atomic ratio of In is 5, the atomic ratio of Ga is more than 0.1 and 2 or less, and the atomic ratio of Zn is 5 or more and 7 or less. Furthermore, when describing a composition having an atomic ratio of In:Ga:Zn=1:1:1 or thereabout, this includes a case where, when the atomic ratio of In is 1, the atomic ratio of Ga is more than 0.1 and 2 or less, and the atomic ratio of Zn is more than 0.1 and 2 or less.

[0302] The crystallinity of a semiconductor material used for a transistor is not particularly limited, and any of an amorphous semiconductor and a crystalline semiconductor (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor having a crystalline region in part) may be used. The use of a crystalline semiconductor is preferable because it can suppress deterioration of transistor characteristics.

[0303] The semiconductor layer of the transistor preferably includes a metal oxide (also referred to as an oxide semiconductor). Examples of a crystalline oxide semiconductor include a c-axis-aligned crystalline (CAAC)-OS and a nanocrystalline (nc)-OS.

[0304] Alternatively, a transistor using silicon for a channel formation region (Si transistor) may be used. Examples of silicon include single crystal silicon (single crystal Si), polycrystalline silicon, and amorphous silicon. In particular, a transistor having low temperature polysilicon (LTPS) in a semiconductor layer (hereinafter also referred to as an LTPS transistor) may be used. An LTPS transistor has high field-effect mobility and favorable frequency characteristics.

[0305] By using Si transistors such as LTPS transistors, circuits that need to be driven at high frequencies (such as a source driver circuit) can be built on the same substrate as the display unit, which simplifies the external circuits mounted on the light-emitting device and reduces component and mounting costs.

[0306] An OS transistor has significantly higher field-effect mobility than a transistor using amorphous silicon. Furthermore, an OS transistor has significantly lower source-drain leakage current in an off state (hereinafter also referred to as off-state current), and can retain charge accumulated in a capacitor connected in series with the transistor for a long period of time. Furthermore, the use of an OS transistor can reduce the power consumption of a light-emitting device.

[0307] The off-state current of the OS transistor per 1 μm of channel width at room temperature is 1 aA (1×10 −１８ A) Below, 1zA (1×10 −２１ A) or less, or 1 yA (1 x 10 −２４ Note that the off-state current of a Si transistor per 1 μm of channel width at room temperature can be 1 fA (1×10 −１５ A) More than 1pA (1×10 −１２Therefore, it can be said that the off-state current of an OS transistor is about 10 orders of magnitude lower than that of a Si transistor.

[0308] Furthermore, to increase the emission luminance of a light-emitting device included in a pixel circuit, it is necessary to increase the amount of current flowing through the light-emitting device. To achieve this, it is necessary to increase the source-drain voltage of a driving transistor included in the pixel circuit. Since an OS transistor has a higher source-drain withstand voltage than a Si transistor, a high voltage can be applied between the source and drain of the OS transistor. Therefore, by using an OS transistor as the driving transistor included in a pixel circuit, it is possible to increase the amount of current flowing through the light-emitting device and increase the emission luminance of the light-emitting device.

[0309] Furthermore, when a transistor operates in the saturation region, an OS transistor can reduce the change in source-drain current with respect to a change in gate-source voltage compared to a Si transistor. Therefore, by using an OS transistor as a driving transistor included in a pixel circuit, the current flowing between the source and drain can be precisely controlled by changing the gate-source voltage, thereby controlling the amount of current flowing through the light-emitting device. This allows for a larger gradation in the pixel circuit.

[0310] Furthermore, in terms of saturation characteristics of the current that flows when a transistor operates in a saturation region, an OS transistor can pass a more stable current (saturation current) than a Si transistor, even when the source-drain voltage gradually increases. Therefore, by using an OS transistor as a driving transistor, a stable current can be passed through a light-emitting device, even when the current-voltage characteristics of the light-emitting device vary. In other words, when an OS transistor operates in a saturation region, the source-drain current of the OS transistor remains almost unchanged even when the source-drain voltage increases, thereby stabilizing the light-emitting luminance of the light-emitting device.

[0311] As described above, by using an OS transistor for a driving transistor included in a pixel circuit, it is possible to achieve "suppression of black floating," "increase in light emission luminance," "multiple gradations," "suppression of variations in light-emitting devices," and the like.

[0312] Alternatively, a semiconductor film used for a transistor in a driver circuit can be formed in the same process as a semiconductor film used for a transistor in a pixel circuit. Alternatively, the driver circuit can be formed over the same substrate as the substrate on which the pixel circuit is formed. Alternatively, the number of components constituting an electronic device can be reduced.

[0313] Silicon may also be used for the semiconductor film 508. Examples of silicon include single crystal silicon, polycrystalline silicon, and amorphous silicon. In particular, a transistor having low temperature polysilicon (LTPS) in a semiconductor layer (hereinafter also referred to as an LTPS transistor) is preferably used. An LTPS transistor has high field-effect mobility and favorable frequency characteristics.

[0314] By using silicon transistors such as LTPS transistors, circuits that need to be driven at high frequencies (such as a source driver circuit) can be built on the same substrate as the display unit, which simplifies the external circuits mounted on the light-emitting device and reduces component and mounting costs.

[0315] At least one of the transistors included in the pixel circuit preferably includes a transistor (hereinafter also referred to as an OS transistor) having a metal oxide (hereinafter also referred to as an oxide semiconductor) as a semiconductor in which a channel is formed. The OS transistor has significantly higher field-effect mobility than a transistor using amorphous silicon. Furthermore, the OS transistor has significantly lower source-drain leakage current in an off state (hereinafter also referred to as an off-state current), and can retain charge accumulated in a capacitor connected in series with the transistor for a long period of time. Furthermore, the use of an OS transistor can reduce the power consumption of a light-emitting device.

[0316] By using LTPS transistors for some of the transistors included in a pixel circuit and OS transistors for the other transistors, a light-emitting device with low power consumption and high driving capability can be realized. As a more preferred example, it is preferable to use OS transistors as transistors that function as switches for controlling conduction / non-conduction between wirings, and LTPS transistors as transistors that control current. Note that a structure in which both LTPS transistors and OS transistors are combined is sometimes referred to as LTPO. By using LTPO, a display panel with low power consumption and high driving capability can be realized.

[0317] For example, one of the transistors provided in the pixel circuit functions as a transistor for controlling a current flowing through a light-emitting device and can be called a driving transistor. One of the source and drain of the driving transistor is electrically connected to a pixel electrode of the light-emitting device. It is preferable to use an LTPS transistor as the driving transistor. This allows the current flowing through the light-emitting device in the pixel circuit to be increased.

[0318] On the other hand, another transistor provided in the pixel circuit functions as a switch for controlling pixel selection / non-selection and can also be called a selection transistor. The gate of the selection transistor is electrically connected to a gate line, and one of the source and drain is electrically connected to a source line (signal line). It is preferable to use an OS transistor as the selection transistor. This allows the gradation of a pixel to be maintained even when the frame frequency is significantly reduced (for example, 1 fps or less), and therefore power consumption can be reduced by stopping the driver when displaying a still image.

[0319] When an oxide semiconductor is used for the semiconductor film, the device 720 has a structure in which the oxide semiconductor is used for the semiconductor film and a light-emitting device with an MML (metal maskless) structure. This structure can significantly reduce leakage current that may flow through a transistor and leakage current that may flow between adjacent light-emitting devices (also referred to as lateral leakage current or side leakage current). Furthermore, with this structure, when an image is displayed on a display device, a viewer can observe one or more of image clarity, image sharpness, high saturation, and a high contrast ratio. Note that a structure in which leakage current that may flow through a transistor and lateral leakage current between light-emitting devices are extremely low can provide a display (also referred to as true black display) with extremely low light leakage (so-called floating black) that may occur during black display.

[0320] In particular, among light-emitting devices with an MML structure, by applying the SBS structure described above, the layers provided between the light-emitting devices (for example, organic layers used in common between the light-emitting devices, also called common layers) are configured to be separated, thereby making it possible to achieve a display with no side leakage or extremely little side leakage.

[0321] The configuration of the transistors used in the display panel may be appropriately selected depending on the screen size of the display panel. For example, when single-crystal silicon transistors are used as transistors in the display panel, the display panel can be applied to a screen size having a diagonal size of 0.1 to 3 inches. When LTPS transistors are used as transistors in the display panel, the display panel can be applied to a screen size having a diagonal size of 0.1 to 30 inches, preferably 1 to 30 inches. When LTPO transistors (combination of LTPS transistors and OS transistors) are used in the display panel, the display panel can be applied to a screen size having a diagonal size of 0.1 to 50 inches, preferably 1 to 50 inches. When OS transistors are used as transistors in the display panel, the display panel can be applied to a screen size having a diagonal size of 0.1 to 200 inches, preferably 50 to 100 inches.

[0322] It is very difficult to increase the size of a single-crystal Si transistor due to the size of a single-crystal Si substrate. Furthermore, since a laser crystallization apparatus is used in the manufacturing process of an LTPS transistor, it is difficult to accommodate large screen sizes (typically, screen sizes exceeding 30 inches in diagonal size). On the other hand, since an OS transistor is not restricted by the use of a laser crystallization apparatus or can be manufactured at a relatively low process temperature (typically, 450° C. or lower), it is possible to accommodate display panels with a relatively large area (typically, a diagonal size of 50 inches to 100 inches). Furthermore, LTPO can be applied to display panel sizes (typically, a diagonal size of 1 inch to 50 inches) that are between those of an LTPS transistor and an OS transistor.

[0323] Next, a cross-sectional view of the light emitting and receiving device is shown in Fig. 11. Fig. 11 shows a cross-sectional view of the light emitting and receiving device shown in Fig. 9A.

[0324] The cross-sectional view of FIG. 11 shows a cross-sectional view of a part of the region including the FPC 713 and the wiring 706, and a part of the display region 701 including the pixel 703(i, j).

[0325] 11 , the light emitting and receiving device 700 has a functional layer 520 between a first substrate 510 and a second substrate 770. The functional layer 520 includes the transistors (M11, M12, M13, M14, M15, M16, M17) and capacitance elements (C2, C3) described in FIG. 10 , as well as wiring (VS, VG, V1, V2, V3, V4, V5) that electrically connect these elements. Note that, in FIG. 11 , the functional layer 520 includes a pixel circuit 530X(i, j), a pixel circuit 530S(i, j), and a drive circuit GD, but is not limited to this.

[0326] Furthermore, the pixel circuits formed in the functional layer 520 (for example, the pixel circuits 530X(i,j) and 530S(i,j) shown in FIG. 11 ) are electrically connected to the light-emitting devices and light-receiving devices formed on the functional layer 520 (for example, the light-emitting devices 550X(i,j) and 550S(i,j) shown in FIG. 11 ). Specifically, the light-emitting devices 550X(i,j) are electrically connected to the pixel circuits 530X(i,j) via wiring 591X, and the light-receiving devices 550S(i,j) are electrically connected to the pixel circuits 530S(i,j) via wiring 591S. Furthermore, an insulating layer 705 is provided on the functional layer 520, the light-emitting devices, and the light-receiving devices, and the insulating layer 705 has the function of bonding the second substrate 770 and the functional layer 520 together.

[0327] Note that a substrate provided with touch sensors arranged in a matrix can be used as the second substrate 770. For example, a substrate provided with a capacitive touch sensor or an optical touch sensor can be used as the second substrate 770. In this way, the light-emitting and receiving device of one embodiment of the present invention can be used as a touch panel.

[0328] Note that the structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0329] Embodiment 5 In this embodiment, structures of electronic devices of one embodiment of the present invention will be described with reference to FIGS. 12A to 14B. FIG.

[0330] 12A to 14B are diagrams illustrating the structure of an electronic device of one embodiment of the present invention. FIG. 12A is a block diagram of the electronic device, and FIGS. 12B to 12E are perspective views illustrating the structure of the electronic device. FIGS. 13A to 13E are perspective views illustrating the structure of the electronic device. FIGS. 14A and 14B are perspective views illustrating the structure of the electronic device.

[0331] An electronic device 5200B described in this embodiment includes an arithmetic device 5210 and an input / output device 5220 (see FIG. 12A).

[0332] The arithmetic unit 5210 has a function of receiving operation information and a function of supplying image information based on the operation information.

[0333] The input / output device 5220 has a display unit 5230, an input unit 5240, a detection unit 5250, a communication unit 5290, a function to supply operation information, and a function to be supplied with image information. The input / output device 5220 also has a function to supply detection information, a function to supply communication information, and a function to be supplied with communication information.

[0334] The input unit 5240 has a function of supplying operation information. For example, the input unit 5240 supplies operation information based on an operation by the user of the electronic device 5200B.

[0335] Specifically, the input unit 5240 can use a keyboard, hardware buttons, a pointing device, a touch sensor, an illuminance sensor, an imaging device, a voice input device, an eye-gaze input device, an attitude detection device, or the like.

[0336] The display portion 5230 has a function of displaying a display panel and displaying image information. For example, the display panel described in Embodiment 3 can be used as the display portion 5230.

[0337] The detection unit 5250 has a function of supplying detection information, for example, a function of detecting the surrounding environment in which the electronic device is used and supplying the detected information.

[0338] Specifically, an illuminance sensor, an imaging device, a posture detection device, a pressure sensor, a human sensor, or the like can be used for the detection unit 5250 .

[0339] The communication unit 5290 has a function of receiving and supplying communication information. For example, it has a function of connecting to other electronic devices or communication networks by wireless communication or wired communication. Specifically, it has functions such as wireless local area communication, telephone communication, and short-range wireless communication.

[0340] FIG. 12B shows an electronic device having an outline conforming to a cylindrical pillar or the like. An example of such an electronic device is a digital signage device. The display panel of one embodiment of the present invention can be applied to the display portion 5230. Note that the display panel may have a function of changing the display method depending on the illuminance of the usage environment. Furthermore, the display panel may have a function of detecting the presence of a person and changing the display content. This allows the display panel to be installed on a pillar of a building, for example. Alternatively, advertisements, notices, or the like can be displayed.

[0341] 12C shows an electronic device having a function of generating image information based on the trajectory of a pointer used by a user. Examples include an electronic whiteboard, an electronic bulletin board, and an electronic signboard. Specifically, a display panel with a diagonal length of 20 inches or more, preferably 40 inches or more, and more preferably 55 inches or more can be used. Alternatively, multiple display panels can be arranged to form a single display area. Alternatively, multiple display panels can be arranged to form a multi-screen.

[0342] 12D shows an electronic device that can receive information from another device and display it on the display unit 5230. An example of such an electronic device is a wearable electronic device. Specifically, it can display several options, or the user can select several options and send a reply to the sender of the information. Alternatively, it can have a function to change the display method depending on the illuminance of the usage environment. This can reduce the power consumption of the wearable electronic device, for example. Alternatively, it can display an image on the wearable electronic device so that it can be used effectively even in environments with strong external light, such as outdoors on a sunny day.

[0343] 12E shows an electronic device having a display unit 5230 with a curved surface that gently curves along the side of the housing. An example is a mobile phone. The display unit 5230 includes a display panel, which has a function of displaying information on, for example, the front, side, top, and back of the mobile phone. This allows information to be displayed not only on the front, but also on the side, top, and back of the mobile phone.

[0344] 13A shows an electronic device that can receive information from the Internet and display it on the display unit 5230. An example of such an electronic device is a smartphone. For example, a created message can be checked on the display unit 5230. Alternatively, the created message can be transmitted to another device. Alternatively, the smartphone may have a function to change the display method depending on the illuminance of the usage environment. This can reduce the power consumption of the smartphone. Alternatively, for example, an image can be displayed on the smartphone so that the smartphone can be used effectively even in an environment with strong external light, such as outdoors on a sunny day.

[0345] FIG. 13B shows an electronic device that can use a remote controller as the input unit 5240. An example is a television system. Alternatively, for example, information can be received from a broadcasting station or the Internet and displayed on the display unit 5230. Alternatively, a user can be photographed using the detection unit 5250. An image of the user can be transmitted. Alternatively, the user's viewing history can be acquired and provided to a cloud service. Alternatively, recommendation information can be acquired from a cloud service and displayed on the display unit 5230. Alternatively, a program or video can be displayed based on the recommendation information. Alternatively, for example, the device has a function to change the display method depending on the illuminance of the usage environment. This allows images to be displayed on the television system so that it can be used appropriately even when strong external light shines indoors on a sunny day.

[0346] 13C shows an electronic device that can receive learning materials from the Internet and display them on the display unit 5230. An example is a tablet computer. Alternatively, a report can be input using the input unit 5240 and sent to the Internet. Alternatively, the results of corrections or evaluations of the report can be obtained from a cloud service and displayed on the display unit 5230. Alternatively, suitable learning materials can be selected and displayed based on the evaluations.

[0347] For example, an image signal can be received from another electronic device and displayed on the display unit 5230. Alternatively, the display unit 5230 can be used as a sub-display by being placed on a stand or the like. This allows images to be displayed on the tablet computer so that the tablet computer can be used suitably even in an environment with strong external light, such as outdoors on a sunny day.

[0348] FIG. 13D shows an electronic device having multiple display units 5230. An example is a digital camera. For example, an image can be captured by the detection unit 5250 and displayed on the display unit 5230. Alternatively, the captured image can be displayed on the detection unit. Alternatively, the captured image can be decorated using the input unit 5240. Alternatively, a message can be attached to the captured image. Alternatively, the captured image can be transmitted to the Internet. Alternatively, the electronic device has a function to change the capture conditions depending on the illuminance of the usage environment. This allows the subject to be displayed on the digital camera so that it can be viewed appropriately even in an environment with strong external light, such as outdoors on a sunny day.

[0349] 13E shows an electronic device that can control another electronic device using the electronic device of this embodiment as a master, with the other electronic device used as a slave. One example is a portable personal computer. For example, part of the image information can be displayed on the display unit 5230, and another part of the image information can be displayed on the display unit of the other electronic device. Alternatively, an image signal can be supplied. Alternatively, information to be written can be obtained from the input unit of the other electronic device using the communication unit 5290. This allows, for example, a portable personal computer to utilize a large display area.

[0350] FIG. 14A shows an electronic device having a detection unit 5250 that detects acceleration or orientation. An example is a goggle-type electronic device. Alternatively, the detection unit 5250 can provide information related to the user's position or the direction the user is facing. Alternatively, the electronic device can generate image information for the right eye and image information for the left eye based on the user's position or the direction the user is facing. Alternatively, the display unit 5230 has a display area for the right eye and a display area for the left eye. This allows, for example, an immersive virtual reality space image to be displayed on the goggle-type electronic device.

[0351] 14B shows an electronic device having a detection unit 5250 that detects an imaging device, acceleration, or orientation. An example is a glasses-type electronic device. Alternatively, the detection unit 5250 can provide information related to the user's position or the direction the user is facing. Alternatively, the electronic device can generate image information based on the user's position or the direction the user is facing. This allows, for example, information to be attached to a real-world scene and displayed. Alternatively, an image of an augmented reality space can be displayed on the glasses-type electronic device.

[0352] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0353] In this embodiment, a structure in which the light-emitting device described in Embodiment 2 is used as a lighting device will be described with reference to Fig. 15. Fig. 15A is a cross-sectional view taken along line e-f in the top view of the lighting device shown in Fig. 15B.

[0354] In the lighting device of this embodiment, a first electrode 401 is formed over a light-transmitting substrate 400 which serves as a support. The first electrode 401 corresponds to the first electrode 101 in Embodiment 2. When light is extracted from the first electrode 401 side, the first electrode 401 is formed using a light-transmitting material.

[0355] A pad 412 for supplying a voltage to the second electrode 404 is formed on the substrate 400 .

[0356] An EL layer 403 is formed over the first electrode 401. The EL layer 403 has a structure corresponding to the EL layer 103 in Embodiment Mode 2. For the structure thereof, refer to the description therein.

[0357] A second electrode 404 is formed to cover the EL layer 403. The second electrode 404 corresponds to the second electrode 102 in Embodiment Mode 2. When light is extracted from the first electrode 401 side, the second electrode 404 is formed using a material with high reflectivity. The second electrode 404 is connected to a pad 412 to supply a voltage.

[0358] As described above, the lighting device described in this embodiment has a light-emitting device including the first electrode 401, the EL layer 403, and the second electrode 404. Since the light-emitting device has high emission efficiency, the lighting device in this embodiment can have low power consumption.

[0359] The substrate 400 on which the light-emitting device having the above configuration is formed is fixed to a sealing substrate 407 using sealing materials (405, 406) to complete the lighting device. Either one of the sealing materials 405 or 406 can be used. Also, a desiccant can be mixed into the inner sealing material 406 (not shown in FIG. 15B ), which can absorb moisture and improve reliability.

[0360] Furthermore, the pad 412 and a part of the first electrode 401 can be provided as an external input terminal by extending them outside the sealing materials 405 and 406. Furthermore, an IC chip 420 or the like on which a converter or the like is mounted may be provided thereon.

[0361] Embodiment 7 In this embodiment, an application example of a lighting device manufactured using a light-emitting device which is one embodiment of the present invention or a light-emitting device which is a part of the light-emitting device will be described with reference to FIGS.

[0362] The indoor lighting device can be applied as a ceiling light 8001. Ceiling lights 8001 are available in direct ceiling mount and recessed ceiling types. Such lighting devices are constructed by combining a light emitting device with a housing and a cover. It can also be applied to cord pendant types (hanging from the ceiling with a cord).

[0363] The foot lamp 8002 can also project light onto the floor, improving safety around the feet. For example, it is effective for use in bedrooms, stairs, and corridors. In this case, the size and shape can be changed appropriately depending on the size and structure of the room. It can also be used as a stationary lighting device configured by combining a light-emitting device with a support base.

[0364] The sheet lighting 8003 is a thin sheet-like lighting device. Since it is attached to a wall surface, it does not take up much space and can be used for a wide range of purposes. It can also be easily made larger. It can also be used on curved walls, housings, etc.

[0365] It is also possible to use a lighting device 8004 in which light from a light source is controlled to only a desired direction.

[0366] The desk lamp 8005 includes a light source 8006 , and the light-emitting device according to one embodiment of the present invention or a light-emitting device that is a part of the light-emitting device can be used as the light source 8006 .

[0367] In addition to the above, by applying the light-emitting device of one embodiment of the present invention or a light-emitting device that is a part of the light-emitting device to a part of furniture installed in a room, the lighting device can have the function of the furniture.

[0368] As described above, various lighting devices using the light-emitting device can be obtained. Note that these lighting devices are included in one embodiment of the present invention.

[0369] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0370] In this embodiment, a light-emitting device and a light-receiving device that can be applied to a display device of one embodiment of the present invention will be described with reference to FIG. 17. Note that the light-emitting and receiving device 810 can be called a light-emitting device because it includes a light-emitting device, and can be called a light-receiving device because it includes a light-receiving device. Furthermore, since the light-emitting and receiving device 810 can be applied to a display portion of an electronic device or the like, it can also be called a display panel or a display device.

[0371] FIG. 17A is a schematic cross-sectional view of a light-emitting device 805a and a light-receiving device 805b included in a light-emitting and receiving device 810 of one embodiment of the present invention.

[0372] The light-emitting device 805a has a function of emitting light (hereinafter also referred to as a light-emitting function). The light-emitting device 805a includes an electrode 801a, an EL layer 803a, and an electrode 802. The light-emitting device 805a is preferably a light-emitting device (organic EL device) that utilizes the organic EL described in Embodiment 2. Therefore, the EL layer 803a sandwiched between the electrode 801a and the electrode 802 includes at least a light-emitting layer. The light-emitting layer includes a light-emitting substance. Light is emitted from the EL layer 803a by applying a voltage between the electrode 801a and the electrode 802. The EL layer 803a may include various layers, such as a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a carrier (hole or electron) blocking layer, and a charge generation layer, in addition to the light-emitting layer.

[0373] The light-receiving device 805b has a function of detecting light (hereinafter also referred to as a light-receiving function). The light-receiving device 805b can be, for example, a pn-type or pin-type photodiode. The light-receiving device 805b has an electrode 801b, a light-receiving layer 803b, and an electrode 802. The light-receiving layer 803b sandwiched between the electrode 801b and the electrode 802 has at least an active layer. The light-receiving layer 803b can also be made of the materials used for the various layers of the EL layer 803a described above (e.g., hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer, carrier (hole or electron) blocking layer, charge generation layer, etc.). The light-receiving device 805b functions as a photoelectric conversion device, generating charges by light incident on the light-receiving layer 803b and extracting them as a current. At this time, a voltage may be applied between the electrode 801b and the electrode 802. The amount of generated charge is determined based on the amount of light incident on the light receiving layer 803b.

[0374] The light receiving device 805b has a function of detecting visible light. The light receiving device 805b is sensitive to visible light. It is more preferable that the light receiving device 805b has a function of detecting visible light and infrared light. It is preferable that the light receiving device 805b is sensitive to visible light and infrared light.

[0375] In this specification, the blue (B) wavelength region is defined as 400 nm or more and less than 490 nm, and blue (B) light has at least one emission spectrum peak in this wavelength region. The green (G) wavelength region is defined as 490 nm or more and less than 580 nm, and green (G) light has at least one emission spectrum peak in this wavelength region. The red (R) wavelength region is defined as 580 nm or more and less than 700 nm, and red (R) light has at least one emission spectrum peak in this wavelength region. In this specification, the visible light wavelength region is defined as 400 nm or more and less than 700 nm, and visible light has at least one emission spectrum peak in this wavelength region. The infrared (IR) wavelength region is defined as 700 nm or more and less than 900 nm, and infrared (IR) light has at least one emission spectrum peak in this wavelength region.

[0376] The active layer of the light-receiving device 805b includes a semiconductor. Examples of the semiconductor include inorganic semiconductors such as silicon and organic semiconductors containing organic compounds. The light-receiving device 805b preferably uses an organic semiconductor device (or an organic photodiode) whose active layer includes an organic semiconductor. Organic photodiodes can be easily thinned, lightweight, and enlarged, and have high flexibility in shape and design, making them applicable to various display devices. Furthermore, using an organic semiconductor is preferable because the EL layer 803a of the light-emitting device 805a and the light-receiving layer 803b of the light-receiving device 805b can be formed by the same method (e.g., vacuum evaporation) and can use a common manufacturing equipment. The light-receiving layer 803b of the light-receiving device 805b can be formed using an organic compound according to one embodiment of the present invention.

[0377] In a display device according to one embodiment of the present invention, an organic EL device can be used as the light-emitting device 805a, and an organic photodiode can be used as the light-receiving device 805b. The organic EL device and the organic photodiode can be formed over the same substrate. Therefore, an organic photodiode can be built into a display device using an organic EL device. The display device according to one embodiment of the present invention has one or both of an imaging function and a sensing function in addition to a function of displaying an image.

[0378] 17A shows a configuration in which the electrodes 801a and 801b are provided on a substrate 800. The electrodes 801a and 801b can be formed by, for example, processing a conductive film formed on the substrate 800 into an island shape. In other words, the electrodes 801a and 801b can be formed through the same process.

[0379] A heat-resistant substrate capable of withstanding the formation of the light-emitting device 805 a and the light-receiving device 805 b can be used as the substrate 800. When an insulating substrate is used as the substrate 800, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, an organic resin substrate, or the like can be used. In addition, a semiconductor substrate such as a single-crystal semiconductor substrate made of silicon, silicon carbide, or the like, a polycrystalline semiconductor substrate, a compound semiconductor substrate such as silicon germanium, or an SOI substrate can be used.

[0380] In particular, it is preferable to use the above-mentioned insulating substrate or a substrate on which a semiconductor circuit including a semiconductor element such as a transistor is formed as the substrate 800. The semiconductor circuit preferably constitutes, for example, a pixel circuit, a gate line driving circuit (gate driver), a source line driving circuit (source driver), etc. In addition to the above, an arithmetic circuit, a memory circuit, etc. may also be configured.

[0381] The electrode 802 is an electrode made of a layer common to the light-emitting device 805 a and the light-receiving device 805 b. Of these electrodes, a conductive film that transmits visible light and infrared light is used for the electrode on the side that emits or receives light. It is preferable to use a conductive film that reflects visible light and infrared light for the electrode on the side that does not emit or receive light.

[0382] The electrode 802 in the display device which is one embodiment of the present invention functions as one electrode of each of the light-emitting device 805a and the light-receiving device 805b.

[0383] 17B shows a case where electrode 801a of light-emitting device 805a has a higher potential than electrode 802. In this case, electrode 801a functions as the anode of light-emitting device 805a, and electrode 802 functions as the cathode. Furthermore, electrode 801b of light-receiving device 805b has a lower potential than electrode 802. Note that in FIG. 17B, to make it easier to understand the direction of current flow, the circuit symbol for a light-emitting diode is shown to the left of light-emitting device 805a, and the circuit symbol for a photodiode is shown to the right of light-receiving device 805b. Furthermore, the direction of carrier (electron and hole) flow is schematically indicated by arrows in each device.

[0384] In the configuration shown in Figure 17B, when a first potential is supplied to electrode 801a via a first wiring, a second potential is supplied to electrode 802 via a second wiring, and a third potential is supplied to electrode 801b via a third wiring, the relationship in magnitude of each potential is first potential > second potential > third potential.

[0385] 17C shows a case where electrode 801a of light-emitting device 805a has a lower potential than electrode 802. In this case, electrode 801a functions as the cathode of light-emitting device 805a, and electrode 802 functions as the anode. Electrode 801b of light-receiving device 805b has a lower potential than electrode 802 and a higher potential than electrode 801a. In FIG. 17B, to make it easier to understand the direction of current flow, the circuit symbol for a light-emitting diode is shown to the left of light-emitting device 805a, and the circuit symbol for a photodiode is shown to the right of light-receiving device 805b. The direction of carrier (electron and hole) flow is also indicated by arrows in each device.

[0386] In the configuration shown in Figure 17C, in light-emitting device 805a, when a first potential is supplied to electrode 801a via a first wiring, a second potential is supplied to electrode 802 via a second wiring, and a third potential is supplied to electrode 801b via a third wiring, the relationship in magnitude of each potential is second potential > third potential > first potential.

[0387] 18A shows a light-receiving and light-emitting device 810A, which is a modified example of the light-receiving and light-emitting device 810. The light-receiving and light-emitting device 810A differs from the light-receiving and light-emitting device 810A in that it includes common layers 806 and 807. In the light-emitting device 805a, the common layers 806 and 807 function as part of the EL layer 803a. In the light-receiving device 805b, the common layers 806 and 807 function as part of the light-receiving layer 803b. The common layer 806 includes, for example, a hole injection layer and a hole transport layer. The common layer 807 includes, for example, an electron transport layer and an electron injection layer.

[0388] By adopting a configuration including the common layer 806 and the common layer 807, it is possible to incorporate a light receiving device without significantly increasing the number of times of coating, and it is possible to manufacture the light receiving and emitting device 810A with high throughput.

[0389] FIG. 18B shows a light-receiving and light-emitting device 810B, which is a modification of the light-receiving and light-emitting device 810. The light-receiving and light-emitting device 810B differs from the light-receiving and light-emitting device 810 in that the EL layer 803a includes layers 806a and 807a, and the light-receiving layer 803b includes layers 806b and 807b. The layers 806a and 806b are made of different materials and include, for example, a hole injection layer and a hole transport layer. The layers 806a and 806b may be made of the same material. The layers 807a and 807b are made of different materials and include, for example, an electron transport layer and an electron injection layer. The layers 807a and 807b may be made of the same material.

[0390] By selecting the most suitable materials for constituting the light-emitting device 805a for the layers 806a and 807a, and the most suitable materials for constituting the light-receiving device 805b for the layers 806b and 807b, the performance of each of the light-emitting device 805a and the light-receiving device 805b in the light-receiving and light-emitting device 810B can be improved.

[0391] Note that the resolution of the light-receiving device 805b described in this embodiment can be 100 ppi or more, preferably 200 ppi or more, more preferably 300 ppi or more, more preferably 400 ppi or more, and further preferably 500 ppi or more, and can be 2000 ppi or less, 1000 ppi or less, or 600 ppi or less. In particular, when the light-receiving device 805b is arranged with a resolution of 200 ppi to 600 ppi, preferably 300 ppi to 600 ppi, the light-receiving device 805b can be suitably used for imaging a fingerprint. When fingerprint authentication is performed using the display device of one embodiment of the present invention, increasing the resolution of the light-receiving device 805b enables, for example, extraction of fingerprint minutia with high accuracy, thereby improving the accuracy of fingerprint authentication. Furthermore, a resolution of 500 ppi or higher is preferable because it allows compliance with standards such as those of the National Institute of Standards and Technology (NIST). Assuming that the resolution of the light-receiving device is 500 ppi, the size per pixel is 50.8 μm, which is sufficient resolution for capturing an image of the width of a fingerprint (typically, 300 μm to 500 μm).

[0392] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0393] Synthesis Example 1 In this example, bis[hydrotris(pyrazolide-N1)borate(1-)-N2,N2′,N2″][dihydrobis(pyrazolide-N1)borate(1-)-N2,N2′]cerium(III) (abbreviation: [Ce(bpz ３ ) ２ (bpz ２ The synthesis method of [Ce(bpz)] will be described. ３ ) ２ (bpz ２ ) )] is shown below.

[0394]

[0395] Step 1: Synthesis of potassium bis(1-pyrazolyl)borate. 20 g (294 mmol) of pyrazole and 4.0 g (73.5 mmol) of potassium borohydride were placed in a 200 mL three-neck flask equipped with a reflux column, and the system was purged with nitrogen. 70 mL of dehydrated toluene was added, and the mixture was degassed and stirred at 110°C for 16 hours while heating under reflux. After stirring, the white solid in the reaction solution was filtered with suction, and the white solid on the filter paper was dissolved with heated toluene and collected as a filtrate. The resulting filtrate was cooled to room temperature, resulting in the precipitation of a white solid. The white solid was filtered with suction, washed with dichloromethane and diethyl ether, and then dried to obtain a white solid (7.0 g, yield 51%). The synthesis scheme of Step 1 is shown in Formula (a-1) below.

[0396]

[0397] <Step 2: [Ce(bpz ３ ) ２ (bpz ２ ) ]> 5.0 g (20 mmol) of potassium tris(1-pyrazolyl)borate, 1.9 g (9.9 mmol) of potassium bis(1-pyrazolyl)borate, and 3.7 g (9.9 mmol) of cerium(III) chloride heptahydrate were placed in a 500 mL three-neck flask, and the system was purged with nitrogen. 230 mL of dehydrated methanol was added thereto, and the mixture was stirred at room temperature for 2.5 hours. After stirring, the white solid in the reaction solution was suction-filtered using a membrane filter to obtain a filtrate. The solvent was removed from the filtrate using an evaporator to obtain a white solid. Next, dichloromethane was added to the white solid, and the mixture was centrifuged. The supernatant solution was filtered, and the solvent from the obtained filtrate was removed using an evaporator to obtain a white solid (1.3 g, yield 18%), which is the target organometallic complex. The synthesis scheme of Step 2 is shown in Formula (a-2) below.

[0398]

[0399] 400 mg of the obtained white solid was purified by sublimation at 200° C. for 1.5 hours using a microsublimation purification apparatus to obtain a white solid (143 mg, recovery rate 36%).

[0400] To determine the molecular weight of the sample, matrix-assisted laser desorption-ionization mass spectrometry (MALDI-MS) was performed. The measurement was performed in positive mode. MALDI-MS detected ions with m / z = 713.2, 566.1, and 500.1 in the mass spectrum. From these results, it was possible to determine the molecular weight of the target compound, C ２４ H ２８ B ３ CeN １６ , the composition formula C in which one bis(1-pyrazolyl)boronic acid ligand is removed １８ H ２０ B ２ CeN １２ and a compound having a composition formula C in which one tris(1-pyrazolyl)boronic acid ligand is removed. １５ H １８ B ２ CeN １０ From this, it was estimated that the target organometallic complex [Ce(bpz ３ ) ２ (bpz ２ ) was obtained.

[0401] Next, [Ce(bpz ３ ) ２ (bpz ２ The ultraviolet-visible absorption spectrum (hereinafter simply referred to as "absorption spectrum") and emission spectrum of a dichloromethane solution of [(2-chloro-2-methyl ...

[0402] The measurement results of the absorption spectrum and the emission spectrum are shown in Figure 19. The horizontal axis represents wavelength, and the vertical axis represents absorption intensity and emission intensity. Of the two solid lines, the thin solid line represents the absorption spectrum, and the thick solid line represents the emission spectrum.

[0403] As shown in Figure 19, [Ce(bpz ３ ) ２ (bpz ２ ) has an emission peak at 440 nm, and blue emission was observed from the dichloromethane solution.

[0404] Synthesis Example 2 In this example, bis[hydrotris(1,2,4-triazolide-N1)borate(1-)-N2,N2′,N2″][dihydrobis(1,2,4-triazolide-N1)borate(1-)-N2,N2′]cerium(III) (abbreviation: [Ce(btaz ３ ) ２ (btaz ２ The synthesis method of [Ce(btaz)] will be described. ３ ) ２ (btaz ２ ) )] is shown below.

[0405]

[0406] Step 1: Synthesis of potassium bis(1-triazolyl)borate. 10.0 g (144.8 mmol) of 1,2,4-triazole and 2.0 g (36.2 mmol) of sodium borohydride were placed in a 100 mL three-neck flask equipped with a reflux tower, and the system was purged with nitrogen. 35 mL of dehydrated toluene was added, and after degassing, the mixture was stirred at 110°C for 13 hours while being heated under reflux. After stirring, the solid precipitated in the reaction solution was filtered with suction and washed with dichloromethane. The resulting white solid was dissolved in ethanol and recrystallized using dichloromethane as a poor solvent. The solid was then filtered with suction, washed with dichloromethane, and dried to obtain a white solid (4.9 g, yield 73%). The synthesis scheme of Step 1 is shown in formula (b-1) below.

[0407]

[0408] <Step 2: Synthesis of potassium tris(1-triazolyl)borate> 15.0 g (217.2 mmol) of 1,2,4-triazole and 2.9 g (54.3 mmol) of sodium borohydride were placed in a 100 mL three-neck flask equipped with a reflux tower, and the system was purged with nitrogen. The heating temperature was gradually increased to 190°C, and the mixture was heated and stirred for 5 hours. After the reaction, the solid in the flask was dissolved in ethanol and recrystallized using toluene as a poor solvent. The precipitate was suction filtered, washed with dichloromethane, and dried to obtain a white solid (8.8 g, yield 64%). The synthesis scheme of Step 2 is shown in formula (b-2) below.

[0409]

[0410] <Step 3: [Ce(btaz ３ ) ２ (btaz ２ ) )] > 2.2 g (8.6 mmol) of potassium tris(1-triazolyl)borate, 0.81 g (4.3 mmol) of potassium bis(1-triazolyl)borate, and 1.6 g (4.3 mmol) of cerium(III) chloride heptahydrate were placed in a 300 mL three-neck flask, and the system was purged with nitrogen. 100 mL of dehydrated methanol was added thereto, and the mixture was stirred at room temperature for 64 hours. After stirring, the solvent was distilled off. The resulting solid was suction filtered with hexane to obtain the desired organometallic complex, a white solid (1.8 g, yield 57%). The synthesis scheme of Step 3 is shown in formula (b-3) below.

[0411]

[0412] Next, [Ce(btaz ３ ) ２ (btaz ２ ) in a dichloromethane solution was measured. The emission spectrum was measured using a spectrofluorometer (FP8600, manufactured by JASCO Corporation) in a nitrogen atmosphere. The deoxygenated dichloromethane solution (0.10 mmol / L) was placed in a quartz cell, which was then sealed and measured at room temperature. The measurement results of the emission spectrum are shown in Figure 20. The horizontal axis represents wavelength, and the vertical axis represents emission intensity.

[0413] From the results of FIG. 20, [Ce(btaz ３ ) ２ (btaz ２ ) )] in dichloromethane showed an emission wavelength peak at around 440 nm.

[0414] Next, [Ce(btaz ３ ) ２ (btaz ２ ) )] was measured for its powder. The emission spectrum was measured using an absolute PL quantum yield measurement device (C11347-01, manufactured by Hamamatsu Photonics K.K.) with the powder placed on a petri dish for powder measurement, and measurements were performed at room temperature. The measurement results of the emission spectrum of the obtained powder are shown in Figure 21. The horizontal axis represents wavelength, and the vertical axis represents emission intensity.

[0415] From the results of FIG. 21, [Ce(btaz ３ ) ２ (btaz ２ ) )] powder showed an emission wavelength peak around 413 nm.

[0416] In this example, a light-emitting device according to one embodiment of the present invention was prepared using [Ce(bpz ３ ) ２ (bpz ２ The device structure and characteristics of a light-emitting device 1 using the above-mentioned [CuO 2 ] as a light-emitting layer will be described below. The specific configuration of the light-emitting device 1 used in this example is shown in Table 1. The chemical formulas of the materials used in this example are shown below.

[0417]

[0418]

[0419] <<Fabrication of Light-Emitting Device 1>> The light-emitting device 1 shown in this example has a structure in which, as shown in FIG. 22 , a hole injection layer 911, a hole transport layer 912, a light-emitting layer 913, an electron transport layer 914, and an electron injection layer 915 are sequentially stacked on a first electrode 901 formed on a substrate 900, and a second electrode 902 is stacked on the electron injection layer 915.

[0420] First, a first electrode 901 was formed on a substrate 900. The electrode area was 4 mm ２The dimensions of the substrate 900 were 2 mm×2 mm. A glass substrate was used as the substrate 900. The first electrode 901 was formed by depositing indium tin oxide containing silicon oxide (ITSO) to a thickness of 70 nm by sputtering. In this example, the first electrode 901 functions as an anode.

[0421] Here, as a pretreatment, the surface of the substrate was washed with water, baked at 200° C. for 1 hour, and then subjected to UV ozone treatment for 370 seconds. −４ The substrate was introduced into a vacuum deposition apparatus whose internal pressure had been reduced to about Pa, and was subjected to vacuum baking at 170° C. for 60 minutes in a heating chamber within the vacuum deposition apparatus, after which the substrate was allowed to cool for about 30 minutes.

[0422] Next, a hole injection layer 911 was formed on the first electrode 901. The hole injection layer 911 was formed by evaporating the solution in a vacuum evaporation apparatus for 10 minutes. −４ After reducing the pressure to 10 Pa, 4,4′,4″-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II) and molybdenum oxide (abbreviation: MoOx) were co-evaporated to a thickness of 10 nm so that the mass ratio of DBT3P-II:MoOx was 4:2.

[0423] Next, a hole transport layer 912 was formed on the hole injection layer 911. The hole transport layer 912 was formed by evaporating 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP) to a thickness of 30 nm.

[0424] Next, a light-emitting layer 913 was formed on the hole-transporting layer 912 .

[0425] The light-emitting layer 913 is a compound containing PCCP, 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), and [Ce(bpz ３ ) ２ (bpz ２ ) )] and PCCP:35DCzPPy:[Ce(bpz ３ ) ２ (bpz ２ ) ] = 0.7:0.3:1.

[0426] Next, an electron transport layer 914 was formed on the light-emitting layer 913. The electron transport layer 914 was formed by evaporating 2,2′,2″-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI) to a thickness of 10 nm and then evaporating 2,9-di(2-naphthyl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen) to a thickness of 15 nm.

[0427] Next, an electron injection layer 915 was formed on the electron transport layer 914. The electron injection layer 915 was formed by vapor deposition using lithium fluoride (LiF) so as to have a film thickness of 1 nm.

[0428] Next, a second electrode 902 was formed on the electron injection layer 915. The second electrode 902 was formed by vapor deposition of aluminum so as to have a film thickness of 200 nm. In this example, the second electrode 902 functions as a cathode.

[0429] Through the above steps, a light-emitting device 1 including an EL layer sandwiched between a pair of electrodes was formed on a substrate 900. Note that the hole injection layer 911, the hole transport layer 912, the light-emitting layer 913, the electron transport layer 914, and the electron injection layer 915 described in the above steps are functional layers that constitute the EL layer in one embodiment of the present invention. Furthermore, in all of the vapor deposition steps in the above-described manufacturing method, vapor deposition using a resistance heating method was used.

[0430] The fabricated light-emitting device 1 was sealed in a glove box with a nitrogen atmosphere to prevent exposure to the atmosphere (a sealant was applied to the periphery of the device, and during sealing, UV treatment was performed and heat treatment was performed at 80° C. for 1 hour).

[0431] <Operation Characteristics of Light-Emitting Device 1> Next, the operation characteristics of the light-emitting device 1 were measured. The measurements were carried out at room temperature (an atmosphere maintained at 25°C). The luminance-current density characteristics of the light-emitting device 1 are shown in Fig. 23, the current efficiency-luminance characteristics in Fig. 24, the luminance-voltage characteristics in Fig. 25, the current-voltage characteristics in Fig. 26, and the external quantum efficiency-luminance characteristics in Fig. 27. The 630 cd / m ２ The main initial characteristic values ​​in the vicinity are shown in Table 2 below.

[0432]

[0433] Furthermore, the light-emitting device 1 is supplied with 2.5 mA / cm ２ 28 shows the emission spectrum when a current was passed through the device at a current density of 1000 . As shown in FIG. 28 , the emission spectrum of the light-emitting device 1 has a peak at 440 nm. The light-emitting device 1 is characterized by the organic metal complex, [Ce(bpz ３ ) ２ (bpz ２ ) ].

[0434] GD: driver circuit, IR: sub-pixel, M11: transistor, M12: transistor, M13: transistor, M14: transistor, M15: transistor, M16: transistor, M17: transistor, MS: wiring, PS: sub-pixel, RES: resist mask, RE1: wiring, SE1: wiring, SE: distance, TX: wiring, VG: wiring, VS: wiring, 101: first electrode, 102: second electrode, 103: EL layer, 103a: EL layer, 103b: EL layer, 103B: EL layer, 103G: EL layer, 103R: EL layer, 103PS: light-receiving layer, 104B: hole injection injection / transport layer, 104G: hole injection / transport layer, 104R: hole injection / transport layer, 104PS: hole injection / transport layer, 105B: light-emitting layer, 105G: light-emitting layer, 105R: light-emitting layer, 105PS: active layer, 106: charge generation layer, 106a: charge generation layer, 106b: charge generation layer, 107: insulating layer, 108B: electron transport layer, 108G: electron transport layer, 108R: electron transport layer, 108PS: electron transport layer, 109: electron injection layer, 110B: sacrificial layer, 110G: sacrificial layer, 110R: sacrificial layer, 110PS: sacrificial layer, 111: hole injection layer, 111a: hole injection layer, 111b: Hole injection layer, 112: hole transport layer, 112a: hole transport layer, 112b: hole transport layer, 113: light emitting layer, 113a: light emitting layer, 113b: light emitting layer, 113c: light emitting layer, 114: electron transport layer, 114a: electron transport layer, 114b: electron transport layer, 115: electron injection layer, 115a: electron injection layer, 115b: electron injection layer, 130: connecting portion, 400: substrate, 401: first electrode, 403: EL layer, 404: second electrode, 405: sealing material, 406: sealing material, 407: sealing substrate, 412: pad, 420: IC chip, 501C: insulating film, 501D: insulating film, 504: Conductive film, 506: insulating film, 508: semiconductor film, 508A: region, 508B: region, 508C: region, 510: first substrate, 512A: conductive film, 512B: conductive film, 516: insulating film, 516A: insulating film, 516B: insulating film, 518: insulating film, 520: functional layer, 524: conductive film, 528: partition wall, 528a: resin film, 530: pixel circuit, 530S: pixel circuit, 530X: pixel circuit, 531: pixel circuit, 550: light-emitting device, 550X: light-emitting device, 550S: light-receiving device, 550B: light-emitting device, 550G: light-emitting device, 550R: light-emitting device,550PS: light receiving device, 551B: electrode, 551C: connection electrode, 551G: electrode, 551R: electrode, 551PS: electrode, 552: electrode, 580: gap, 591S: wiring, 591X: wiring, 700: light receiving / emitting device, 701: display area, 702B: sub-pixel, 702G: sub-pixel, 702PS: sub-pixel, 702R: sub-pixel, 702IR: sub-pixel, 703: pixel, 704: circuit, 705: insulating layer, 706: wiring, 710: substrate, 711: substrate, 712: IC, 713: FPC, 720: device, 770: substrate, 800: substrate, 801a: electrode, 801b: electrode, 802: electrode, 803a: EL layer, 803b: Light receiving layer, 805a: light emitting device, 805b: light receiving device, 810: light receiving and emitting device, 810A: light receiving and emitting device, 810B: light receiving and emitting device, 900: substrate, 901: first electrode, 902: second electrode, 911: hole injection layer, 912: hole transport layer, 913: light emitting layer, 914: electron transport layer, 915: electron injection layer, 5200B: electronic device, 5210: arithmetic unit, 5220: input / output device, 5230: display unit, 5240: input unit, 5250: detection unit, 5290: communication unit, 8001: ceiling light, 8002: foot lamp, 8003: sheet lighting, 8004: lighting device, 8005: desk lamp, 8006: light source,

Claims

An organometallic complex represented by General Formula (G1): In general formula (G1), X represents carbon or nitrogen, and the carbon is bonded to any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. １ ~R ３ each independently represents one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. n represents an integer of 1 to 4. The borate ligands may be the same or different from each other. The n of each borate ligand may be the same or different from each other. When n is 2 or more, the X of each borate ligand may be the same or different from each other, the R of each borate ligand may be the same or different from each other, and the R of each borate ligand may be the same or different from each other. ２ may be the same or different. When n is 2 or less, R ３ may be the same or different.) An organometallic complex represented by general formula (G2): (In general formula (G2), R １ ~R ３ each independently represents one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. n represents an integer of 1 to 4. The borate ligands may be the same or different from each other. The n of each borate ligand may be the same or different from each other. When n is 2 or more, the X of each borate ligand may be the same or different from each other, and the R of each borate ligand may be the same or different from each other. １ may be the same or different, and R of each borate ligand ２ may be the same or different. When n is 2 or less, R ３ may be the same or different.) An organometallic complex represented by general formula (G3): (In general formula (G3), １ ~X ３ each independently represents carbon or nitrogen, and the carbon is bonded to any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. １１ ~R １３ , R ２１ ~R ２３ and R ３１ ~R ３３ Each of j, k, and p independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. In addition, j, k, and p each independently represent an integer of 1 to 4. When j is 2 or more, each of X １ may be the same or different, and each R １１ may be the same or different, and each R １２ may be the same or different. When k is 2 or more, each X ２ may be the same or different, and each R ２１ may be the same or different, and each R ２２ may be the same or different. When p is 2 or more, each X ３ may be the same or different, and each R ３１ may be the same or different, and each R ３２ may be the same or different. When j is 2 or less, each R １３ may be the same or different. When k is 2 or less, each R ２３ may be the same or different. When p is 2 or less, each R ３３ may be the same or different.) An organometallic complex represented by general formula (G3'): (In general formula (G3'), X １ ~X ３ each independently represents carbon or nitrogen, and the carbon is bonded to any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. １１ ~R １３ , R ２１ ~R ２３ and R ３１ ~R ３３ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. j represents an integer of 1 to 3. k and p each independently represent an integer of 1 to 4. When j is 2 or more, each X １ may be the same or different, and each R １１ may be the same or different, and each R １２ may be the same or different. When k is 2 or more, each X ２ may be the same or different, and each R ２１ may be the same or different, and each R ２２ may be the same or different. When p is 2 or more, each X ３ may be the same or different, and each R ３１ may be the same or different, and each R ３２ may be the same or different. When j is 2 or less, each R １３ may be the same or different. When k is 2 or less, each R ２３ may be the same or different. When p is 2 or less, each R ３３ may be the same or different.) 　 An organometallic complex represented by general formula (G4): (In general formula (G4), ２ and X ３ each independently represents carbon or nitrogen, and the carbon is bonded to any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. １１ ~R １３ , R ２１ ~R ２３ and R ３１ ~R ３３ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. j, k, and p each independently represent an integer of 1 to 4. When j is 2 or more, each R １１ may be the same or different, and each R １２ may be the same or different. When k is 2 or more, each X ２ may be the same or different, and each R ２１ may be the same or different, and each R ２２ may be the same or different. When p is 2 or more, each X ３ may be the same or different, and each R ３１ may be the same or different, and each R ３２ may be the same or different. When j is 2 or less, each R １３ may be the same or different. When k is 2 or less, each R ２３ may be the same or different. When p is 2 or less, each R ３３ may be the same or different.) 　 An organometallic complex represented by general formula (G5): (In general formula (G5), １１ ~X １３ , X ２１ ~X ２３ , X ３１ and X ３２ each independently represents carbon or nitrogen, and the carbon is bonded to any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. ４１ ~R ４７ , R ５１ ~R ５７ and R ６１ ~R ６６ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. 　 Organometallic complexes represented by structural formulas (125) and (150). 　 A light-emitting device using the organometallic complex according to any one of claims 1 to 7. 　 A light emitting apparatus comprising the light emitting device according to claim 8 and a transistor or a substrate. 　 An electronic device comprising: the light-emitting device according to claim 9; and a detection unit, an input unit, or a communication unit. 　 A lighting device comprising the light-emitting device according to claim 9 and a housing.

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