Organometallic complex and light-emitting device

Abstract

The present invention provides a novel organometallic complex and a light-emitting device. The present invention provides an organometallic complex represented by general formula (G1). Note that R1, R2, and R4 to R31 each independently represent hydrogen (including deuterium), an alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, at least one of R2 and R4 represents an alkyl group having 1 to 10 carbon atoms, one or more of R18 to R22 represents an alkyl group having 3 to 10 carbon atoms or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, and R23 represents general formula (R-1).

Description

Organometallic complexes, light-emitting devices

[0001] One embodiment of the present invention relates to an organometallic complex, an organic compound, a light-emitting device, a light-receiving device, a light-emitting and receiving device, a light-emitting apparatus, a light-emitting and receiving apparatus, a display 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 and the like 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] 2. Description of the Related Art Organic EL devices (organic EL elements) typified by light-emitting devices, light-receiving devices, and light-emitting / receiving devices that utilize electroluminescence (EL) using organic compounds are increasingly being put to practical use.

[0003] For example, the basic structure of a light-emitting device is a pair of electrodes sandwiching an organic compound layer (EL layer) containing a light-emitting material. 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.

[0004] The basic structure of a light-receiving device is a pair of electrodes sandwiching an organic compound layer (active layer) containing a photoelectric conversion material. This device absorbs light energy and generates carriers, which can then obtain electrons from the photoelectric conversion material.

[0005] For example, a functional panel is known in which pixels provided in a display area include a light-emitting element (light-emitting device) and a photoelectric conversion element (light-receiving device) (Patent Document 1).

[0006] Thus, displays or lighting devices using organic EL devices are suitable for use in a variety of electronic devices, but research and development is ongoing to develop organic EL devices with better efficiency and lifespan.

[0007] Although the characteristics of organic EL devices have improved remarkably, they are still insufficient to meet the high demands for all properties, including efficiency and durability. In particular, to solve problems specific to organic EL devices, such as burn-in, it is desirable to minimize the decrease in efficiency due to degradation.

[0008] Degradation is largely influenced by the luminescent center substance and the materials around it, and therefore, organic compound materials containing organometallic complexes and the like that have good properties have been actively developed (Patent Document 2).

[0009] WO2020 / 152556 JP2024-61664

[0010] An object of one embodiment of the present invention is to provide a novel organometallic complex. Another object of one embodiment of the present invention is to provide an organometallic complex whose excited state is stable. Another object of one embodiment of the present invention is to provide an organometallic complex that can be used as a light-emitting material. Another object of one embodiment of the present invention is to provide an organometallic complex that is easy to synthesize. Another object of one embodiment of the present invention is to provide a light-emitting device having a long operating lifetime. Another object of one embodiment of the present invention is to provide a light-emitting device with small voltage change during operation. Another object of one embodiment of the present invention is to provide a novel light-emitting device. Another object of one embodiment of the present invention is to reduce the manufacturing cost of a light-emitting device. Another object of one embodiment of the present invention is to provide a light-emitting device, electronic device, or lighting device with low power consumption.

[0011] Another object of one embodiment of the present invention is to provide an organometallic complex having a selectively deuterated partial structure, to perform molecular design that can reduce the complexity of the synthetic route, the high temperature and high pressure required for synthesis, and to synthesize an organometallic complex molecularly designed in such a manner.

[0012] 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 solve all of these problems. Note that problems other than these will become apparent from the description of the specification, drawings, claims, etc., and it is possible to extract other problems from the description of the specification, drawings, claims, etc.

[0013] One embodiment of the present invention is an organometallic complex represented by General Formula (G1).

[0014]

[0015] In the above general formula (G1), R １ , R ２ , and R ４ ~R ３１ each independently represents hydrogen (including deuterium), an alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, and R ２ or R ４ At least one of R represents an alkyl group having 1 to 10 carbon atoms; １８ ~R ２２ represents an alkyl group having 3 to 10 carbon atoms or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms; R ２３ represents the following general formula (R-1).

[0016]

[0017] In the general formula (R-1), R ３２ ~R ３６ each independently represents hydrogen (including deuterium), an alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms. In addition, in the above general formula (R-1), the symbol represented by an asterisk (*) represents R ２３ The binding site of

[0018] One embodiment of the present invention is an organometallic complex represented by structural formula (100).

[0019]

[0020] One embodiment of the present invention is a light-emitting device including any of the above organometallic complexes. Another embodiment of the present invention is a light-emitting device including a light-emitting device including any of the above organometallic complexes and a light-receiving device.

[0021] 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.

[0022] 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.

[0023] Another embodiment of the present invention is a lighting device including a light-emitting device having any of the above structures and a housing.

[0024] According to one embodiment of the present invention, a novel organometallic complex can be provided. According to another embodiment of the present invention, an organometallic complex having a stable excited state can be provided. According to another embodiment of the present invention, an organometallic complex that can be used as a light-emitting material can be provided. According to another embodiment of the present invention, an organometallic complex that can be easily synthesized can be provided. According to another embodiment of the present invention, a novel light-emitting device can be provided. According to another embodiment of the present invention, a light-emitting device having a long operating lifetime can be provided. According to another embodiment of the present invention, a light-emitting device with a small change in voltage during operation can be provided. According to another embodiment of the present invention, the manufacturing cost of a light-emitting device can be reduced. According to another embodiment of the present invention, a light-emitting device, an electronic device, or a lighting device with low power consumption can be provided.

[0025] 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.

[0026] FIGS. 1A and 1B are diagrams illustrating a structure of a light-emitting device according to an embodiment. FIGS. 2A, 2B, 2C, 2D, and 2E are diagrams illustrating a structure of a light-emitting device according to an embodiment. FIGS. 3A and 3B are top and cross-sectional views of a light-emitting device. FIGS. 4A, 4B, 4C, and 4D are diagrams illustrating a light-emitting device. FIGS. 5A, 5B, 5C, 5D, and 5E are cross-sectional views illustrating an example of a method for manufacturing a light-emitting device. FIGS. 6A, 6B, 6C, 6D, and 6E are cross-sectional views illustrating an example of a method for manufacturing a light-emitting device. FIGS. 7A, 7B, and 7C are cross-sectional views illustrating an example of a method for manufacturing a light-emitting device. FIGS. 8A, 8B, and 8C are cross-sectional views illustrating an example of a method for manufacturing a light-emitting device. FIGS. 9A, 9B, and 9C are cross-sectional views illustrating an example of a method for manufacturing a light-emitting device. FIGS. 10A, 10B, and 10C are cross-sectional views illustrating an example of a method for manufacturing a light-emitting device. 11A, 11B, and 11C are cross-sectional views illustrating an example of a method for manufacturing a light-emitting device. FIGS. 12A, 12B, 12C, 12D, 12E, 12F, and 12G are top views illustrating examples of pixel configurations. FIGS. 13A, 13B, 13C, 13D, 13E, 13F, 13G, 13H, and 13I are top views illustrating examples of pixel configurations. FIGS. 14A and 14B are perspective views illustrating examples of display modules. FIGS. 15A and 15B are cross-sectional views illustrating examples of light-emitting devices. FIG. 16 is a perspective view illustrating an example of a light-emitting device. FIG. 17A is a cross-sectional view illustrating an example of a light-emitting device. FIGS. 17B and 17C are cross-sectional views illustrating examples of transistors. FIG. 18 is a cross-sectional view illustrating an example of a light-emitting device. FIGS. 19A, 19B, 19C, and 19D are cross-sectional views illustrating examples of light-emitting devices. 20A, 20B, 20C, and 20D are diagrams showing an example of an electronic device. FIGS. 21A, 21B, 21C, 21D, 21E, and 21F are diagrams showing an example of an electronic device. FIGS. 22A, 22B, 22C, 22D, 22E, 22F, and 22G are diagrams showing an example of an electronic device. FIG. 23 shows the structure of an organometallic complex prepared in the example. １FIG. 21 is a diagram illustrating the H NMR spectrum. FIG. 24 is a diagram illustrating the absorption spectrum and emission spectrum of the organometallic complex prepared in the example. FIG. 25 is a diagram illustrating thermogravimetry-differential thermal analysis of the organometallic complex prepared in the example. FIG. 26 is a diagram illustrating the configuration of a device according to the example. FIG. 27 is a diagram illustrating the luminance-current density characteristics of a device according to the example. FIG. 28 is a diagram illustrating the luminance-voltage characteristics of a device according to the example. FIG. 29 is a diagram illustrating the current efficiency-current density characteristics of a device according to the example. FIG. 30 is a diagram illustrating the current density-voltage characteristics of a device according to the example. FIG. 31 is a diagram illustrating the blue index-current density characteristics of a device according to the example. FIG. 32 is a diagram illustrating the external quantum efficiency-current density characteristics of a device according to the example. FIG. 33 is a diagram illustrating the electroluminescence spectrum of a device according to the example. FIG. 34 is a diagram illustrating the structure of a device according to the example. １ FIG. 31 is a diagram illustrating the H NMR spectrum. FIG. 35 is a diagram illustrating the absorption spectrum and emission spectrum of the organometallic complex prepared in Example 3. FIG. 36 is a diagram illustrating thermogravimetry-differential thermal analysis of the organometallic complex prepared in Example 3. FIG. 37 is a diagram illustrating the luminance-current density characteristics of the device according to Example 4. FIG. 38 is a diagram illustrating the luminance-voltage characteristics of the device according to Example 4. FIG. 39 is a diagram illustrating the current efficiency-current density characteristics of the device according to Example 4. FIG. 40 is a diagram illustrating the current density-voltage characteristics of the device according to Example 4. FIG. 41 is a diagram illustrating the blue index-current density characteristics of the device according to Example 4. FIG. 42 is a diagram illustrating the external quantum efficiency-current density characteristics of the device according to Example 4. FIG. 43 is a diagram illustrating the electroluminescence spectrum of the device according to Example 4.

[0027] 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 modifications can be made to the embodiments and details. Furthermore, the present invention should not be interpreted as being limited to the description of the embodiments shown below.

[0028] In this specification, the words "first" and "second" are used for the convenience of understanding the technical content or to identify each component. Therefore, the words "first" and "second" do not limit the number of each component. Furthermore, the words "first" and "second" do not limit the order of each component. Furthermore, the words "first" and "second" or identifying symbols used in this specification may not match the words or identifying symbols in the claims.

[0029] In this specification, the term "deuterated organic compound" refers to an organic compound in which, when focusing on hydrogen (including deuterium) present at a specific position in the organic compound, the proportion of the hydrogen (including deuterium) that is deuterium is greater than the natural abundance of deuterium. This proportion is preferably sufficiently greater than the natural abundance. In this case, "sufficiently" refers to, for example, 7.5% or more being deuterated. The deuteration of an organic compound can be confirmed by methods such as NMR and mass spectrometry. In this specification, hydrogen includes protons and deuterium. Deuterium refers to a stable isotope of hydrogen with a mass number of 2. Protons refer to a stable isotope of hydrogen with a mass number of 1.

[0030] Embodiment 1 In this embodiment, an organometallic complex which is one embodiment of the present invention and a light-emitting device using the organometallic complex will be described.

[0031] <Structure Example of Light-Emitting Device> First, a structure of a light-emitting device of one embodiment of the present invention will be described below with reference to FIGS. 1A and 1B.

[0032] FIG. 1A is a schematic cross-sectional view of a light-emitting device 10 according to one embodiment of the present invention.

[0033] The light-emitting device 10 has a pair of electrodes (a first electrode 101 and a second electrode 102) and an organic compound layer 103 provided between the pair of electrodes. The organic compound layer 103 has at least a light-emitting layer 113.

[0034] The organic compound layer 103 shown in FIG. 1A has functional layers such as a hole injection layer 111 , a hole transport layer 112 , an electron transport layer 114 , and an electron injection layer 115 in addition to the light emitting layer 113 .

[0035] In the present embodiment, the first electrode 101 of the pair of electrodes is described as an anode and the second electrode 102 as a cathode, but the configuration of the light-emitting device 10 is not limited to this. That is, the first electrode 101 may be the cathode and the second electrode 102 may be the anode, and the layers between the electrodes may be stacked in the reverse order. That is, the stacking order may be, from the anode side, the hole injection layer 111, the hole transport layer 112, the light-emitting layer 113, the electron transport layer 114, and the electron injection layer 115.

[0036] 1A , the organic compound layer 103 may have at least one selected from a hole injection layer 111, a hole transport layer 112, an electron transport layer 114, and an electron injection layer 115. Alternatively, the organic compound layer 103 may have a functional layer having a function of reducing the injection barrier of holes or electrons, improving the transportability of holes or electrons, inhibiting the transportability of holes or electrons, or suppressing the quenching phenomenon caused by an electrode. Each functional layer may be a single layer or may have a structure in which multiple layers are stacked.

[0037] 1B is a schematic cross-sectional view illustrating an example of the light-emitting layer 113 shown in FIG. 1A. The light-emitting layer 113 shown in FIG. 1B includes a host material 118 (organic compounds 118_1 and 118_2) and a guest material 119.

[0038] A light-emitting organometallic complex may be used as the guest material 119, and a substance that can emit phosphorescence (hereinafter also referred to as a phosphorescent compound) is preferably used as the light-emitting organometallic complex. In the following description, a structure in which an organometallic complex is used as the guest material 119 will be described.

[0039] In the present invention, an organometallic complex having platinum (Pt) as a central metal is used as the guest material 119. The organometallic complex used in the present invention has a pyridine ring, and the pyridine ring has an alkyl group. The pyridine ring also has a biphenyl group at the 4-position.

[0040] In an organometallic complex having a pyridine ring, an alkyl group is introduced to a carbon atom having a high spin density in a triplet excited state, thereby improving the stability of the compound in the excited state. Furthermore, the alkyl group is preferably deuterated. A deuterated alkyl group is introduced to a carbon atom where the LUMO distribution is concentrated, thereby improving the stability of the compound in a state where an electron has been accepted by the LUMO, i.e., in a reduced state.

[0041] Furthermore, the biphenyl group is introduced to a carbon atom adjacent to a carbon atom where the LUMO distribution is concentrated, thereby broadening the LUMO distribution and stabilizing the LUMO, thereby improving the stability of the compound in a reduced state.

[0042] Furthermore, the alkyl group can exert a steric hindrance effect on the biphenyl group. In particular, when the alkyl group is deuterated, stability can be improved. Furthermore, rotation of the biphenyl group can be suppressed, thereby improving the thermal properties of the compound, such as sublimation. Furthermore, vibration of the compound can be suppressed, thereby suppressing thermal deactivation from the excited state. Furthermore, high luminous efficiency can be achieved. Furthermore, the shape of the emission spectrum can be adjusted by selecting the ligand or the ligand's substituent. Furthermore, the thermal properties of the compound, such as sublimation, can be improved. As a result, a novel organometallic complex with excellent utility and reliability can be provided.

[0043] Furthermore, the pyridine ring of the organometallic complex has an alkyl group. This allows the bond dissociation energy of the compound to be greater than the bond dissociation energy of the carbon-hydrogen bond by utilizing the carbon-deuterium bond. Furthermore, the molecular structure can be stabilized. Furthermore, bond dissociation within the compound structure in an excited state can be suppressed. Furthermore, deterioration or alteration of the compound due to dissociation of the carbon-deuterium bond can be suppressed. Furthermore, when the hydrogen in the alkyl group is deuterated, the above-mentioned effects can be further enhanced.

[0044] Therefore, for example, the organometallic complex of the present invention can be suitably used in the light-emitting layer of a light-emitting device. Furthermore, for example, the organometallic complex of the present invention can be suitably used in a layer in contact with the light-emitting layer of a light-emitting device. Use of the organometallic complex in a light-emitting device can improve reliability.

[0045] <Example of Organometallic Complex> One embodiment of the present invention is an organometallic complex having platinum (Pt) as a central metal, which is represented by the following general formula: An organometallic complex having platinum (Pt) is a substance that can be very suitably used as a material for a light-emitting device.

[0046] One embodiment of the present invention is an organometallic complex represented by General Formula (G1).

[0047]

[0048] However, in the above general formula (G1), R １ , R ２ , and R ４ ~R ３１ each independently represents hydrogen (including deuterium), an alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, and R ２ or R ４ At least one of R represents an alkyl group having 1 to 10 carbon atoms; １８ ~R ２２ at least one of R is an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, ２３ represents the following general formula (R-1).

[0049]

[0050] However, in the above general formula (R-1), R ３２ ~R ３６ each independently represents hydrogen (including deuterium), an alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms.

[0051] In the general formula (G1), R １ , R ２ , R ４ ~R ３１ , and R３２ ~R ３６ Examples of the alkyl group represented by the formula (I) 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 3-methylpentyl group, a 2-methylpentyl group, a 2-ethylbutyl group, a 1,2-dimethylbutyl group, and a 2,3-dimethylbutyl group.

[0052] Also, R １ , R ２ , R ４ ~R ３１ , and R ３２ ~R ３６ Examples of the aryl group represented by the formula (I) include a phenyl group, a biphenyl group, a naphthyl group, a fluorenyl group, a phenanthryl group, an anthryl group, a tetracenyl group, a benzanthracenyl group, a triphenylenyl group, a pyrenyl group, and a spirobi[9H-fluoren]yl group.

[0053] Also, R １ , R ２ , R ４ ~R ３１ , and R ３２ ~R ３６ When any of the groups 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.

[0054] <Specific Examples> Next, specific examples of the organometallic complex which has the structure represented by General Formula (G1) and is one embodiment of the present invention will be shown below.

[0055]

[0056]

[0057]

[0058]

[0059] The organometallic complexes represented by the structural formulas (100) to (122) are examples of the organometallic complexes represented by the general formula (G1); however, the organometallic complexes of one embodiment of the present invention are not limited thereto.

[0060] <Method for synthesizing organometallic complex> A method for synthesizing an organometallic complex represented by general formula (G1) will be described below. Various reactions can be applied as a method for synthesizing the organometallic complex. For example, the organometallic complex represented by general formula (G1) can be synthesized by the following simple synthesis scheme.

[0061] <<Synthesis Method 1>> First, the pyridylcarbazole derivative represented by (A1), which is a starting material for the organometallic complex represented by general formula (G1), can be synthesized by the following synthesis scheme (s1-1): The pyridylcarbazole derivative (A'1) in which phenylbenzimidazole is ether-bridged can be reacted with a hypervalent iodine reagent (A'2) to obtain the pyridylcarbazole derivative (A1).

[0062]

[0063] In the above synthesis scheme (s1-1), R １ , R ２ , and R ４ ~R ３１ each independently represents hydrogen (including deuterium), an alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, and R ２ or R ４ At least one of R represents an alkyl group having 1 to 10 carbon atoms; １８ ~R ２２ at least one of R is an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, ２３ represents the following general formula (R-1).

[0064]

[0065] In the formula, R ３２ ~R ３６each independently represents hydrogen (including deuterium), an alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms.

[0066] Next, as shown in synthetic scheme (s1-2), the organometallic complex represented by general formula (G1) can be obtained by reacting the pyridylcarbazole derivative (A1) obtained in the synthetic scheme (s1-1) with a platinum compound containing a halogen (dichloro(1,5-cyclooctadiene)platinum(II), etc.).

[0067]

[0068] In the above synthesis scheme (s1-2), R １ , R ２ , and R ４ ~R ３１ each independently represents hydrogen (including deuterium), an alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, and R ２ or R ４ At least one of R represents an alkyl group having 1 to 10 carbon atoms; １８ ~R ２２ at least one of R is an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, ２３ represents the following general formula (R-1).

[0069]

[0070] In the formula, R ３２ ~R ３６ each independently represents hydrogen (including deuterium), an alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms.

[0071] <<Synthesis Method 2>> Alternatively, for example, an organometallic complex represented by the general formula (G1) can be synthesized by the following simple synthesis scheme.

[0072] First, the pyridylcarbazole derivative represented by (B1), which is the starting material for general formula (G1), can be synthesized by the following synthesis scheme (s2-1): After cyclization by reacting the pyridylcarbazole derivative (B'1) ether-bridged with a diamine compound with ethyl orthoformate, the pyridylcarbazole derivative (B1) can be obtained by ion exchange with ammonium hexafluorophosphate.

[0073]

[0074] In the above synthesis scheme (s2-1), R １ , R ２ , and R ４ ~R ３１ each independently represents hydrogen (including deuterium), an alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, and R ２ or R ４ At least one of R represents an alkyl group having 1 to 10 carbon atoms; １８ ~R ２２ at least one of R is an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, ２３ represents the following general formula (R-1).

[0075]

[0076] In the formula, R ３２ ~R ３６ each independently represents hydrogen (including deuterium), an alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms.

[0077] Next, as shown in synthetic scheme (s2-2), an organometallic complex represented by general formula (G1) can be obtained by reacting (B1) obtained in the above scheme (s2-1) with a platinum metal compound containing a halogen (dichloro(1,5-cyclooctadiene)platinum(II), etc.).

[0078]

[0079] In the above synthesis scheme (s2-2), R １ , R２ , and R ４ ~R ３１ each independently represents hydrogen (including deuterium), an alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, and R ２ or R ４ At least one of R represents an alkyl group having 1 to 10 carbon atoms; １８ ~R ２２ at least one of R is an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, ２３ represents the following general formula (R-1).

[0080]

[0081] In the formula, R ３２ ~R ３６ each independently represents hydrogen (including deuterium), an alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms.

[0082] Since various types of the above-described compounds (A'1), (A'2), (B'1), and (B'2) are commercially available or can be synthesized, numerous types of organometallic complexes represented by General Formula (G1) can be synthesized. Thus, the compound of one embodiment of the present invention is characterized by a wide variety of compounds.

[0083] Although an example of a method for synthesizing an organometallic complex, which is a compound of one embodiment of the present invention, has been described above, the present invention is not limited thereto, and any other synthesis method may be used for synthesis.

[0084] Note that the compound described in this embodiment can be used in appropriate combination with any of the structures described in other embodiments.

[0085] Embodiment Mode 2 In this embodiment mode, a structure of a light-emitting device using the organometallic complex shown in Embodiment Mode 1 will be described with reference to FIGS. 2A to 2E.

[0086] <Basic Structure of Light-Emitting Device> The basic structure of a light-emitting device will be described. Fig. 2A shows a light-emitting device having a structure (single structure) in which an organic compound layer including a light-emitting layer is disposed between a pair of electrodes. Specifically, the light-emitting device has a structure in which an organic compound layer 103 is sandwiched between a first electrode 101 and a second electrode 102.

[0087] 2B shows a light-emitting device having a stacked structure (tandem structure) in which a plurality of organic compound layers (103a, 103b) (two layers in FIG. 2B) are disposed between a pair of electrodes and a charge generation layer 106 is disposed between the organic compound layers. A light-emitting device having a tandem structure can realize a high-luminance light-emitting device without changing the amount of current.

[0088] The charge generation layer 106 has a function of injecting electrons into one organic compound layer (103a or 103b) and injecting holes into the other organic compound layer (103b or 103a) when a potential difference is generated between the first electrode 101 and the second electrode 102. Therefore, in Fig. 2B, when a voltage is applied to the first electrode 101 so that the potential of the first electrode 101 is higher than that of the second electrode 102, electrons are injected from the charge generation layer 106 into the organic compound layer 103a and holes are injected into the organic compound layer 103b.

[0089] 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.

[0090] 2C shows a stacked structure of the organic compound 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 organic compound 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 emitting different light 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 a layer containing a carrier-transporting material may be interposed between the light-emitting layers. 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 substance and a second light-emitting layer containing a blue light-emitting substance 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. 2B , in which multiple organic compound layers are included, each organic compound 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 organic compound layers 103 is reversed. Specifically, the structure includes an electron injection layer 111 on the first electrode 101 (cathode), an electron transport layer 112, an light-emitting layer 113, a hole transport layer 114, and a hole injection layer 115.

[0091] The light-emitting layers 113 included in the organic compound layers (103, 103a, 103b) each contain a light-emitting substance and an appropriate combination of multiple substances, and can be configured to emit fluorescent or phosphorescent light of a desired emission color. The light-emitting layer 113 may also have a stacked structure with different emission colors. In this case, different materials may be used for the light-emitting substance and other substances used in each stacked light-emitting layer. Alternatively, a structure in which different emission colors are emitted from the multiple organic compound layers (103a, 103b) shown in FIG. 2B may also be used. In this case, different materials may be used for the light-emitting substance and other substances used in each light-emitting layer.

[0092] In addition, in a light-emitting device according to one embodiment of the present invention, for example, the first electrode 101 shown in FIG. 2C may be a reflective electrode, the second electrode 102 may be a semi-transmissive and semi-reflective electrode, and a micro-optical resonator (microcavity) structure may be formed. This allows light emitted from the light-emitting layer 113 included in the organic compound layer 103 to resonate between the two electrodes, thereby enhancing the intensity of light emitted from the second electrode 102. Therefore, high definition can be easily achieved. Furthermore, the intensity of light emitted from a specific wavelength in the front direction can be enhanced, thereby reducing power consumption.

[0093] 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.

[0094] 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 greater) 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.

[0095] 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.

[0096] 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.

[0097] The light-emitting device shown in Figure 2D has a tandem structure. The tandem structure allows for a light-emitting device capable of emitting light with high brightness. Furthermore, the tandem structure reduces the current required to achieve the same brightness compared to a single structure, thereby improving reliability. It also reduces power consumption.

[0098] The light-emitting device shown in FIG. 2E is an example of the tandem-structure light-emitting device shown in FIG. 2B , and as shown in the figure, has a structure in which three organic compound layers (103a, 103b, 103c) are stacked with charge generation layers (106a, 106b) sandwiched between them. The three organic compound layers (103a, 103b, 103c) each have 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.

[0099] 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.

[0100] 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.

[0101] <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. 2D , which has a tandem structure. The single-structure light-emitting devices shown in FIGS. 2A and 2C also have the same organic compound layer structure. When the light-emitting device shown in FIG. 2D has a microcavity structure, the first electrode 101 is formed as a reflective electrode, and the second electrode 102 is formed as a semi-transmissive and semi-reflective electrode. Therefore, the electrode layers can be formed as a single layer or a stack using a single or multiple desired electrode materials. The second electrode 102 is formed by selecting an appropriate material after the organic compound layer 103b is formed.

[0102] <Materials for Light-Emitting Device> <Light-Emitting Layer> The light-emitting layers (113, 113a, 113b) are layers containing a light-emitting substance. As the light-emitting substance that can be used for the light-emitting layers (113, 113a, 113b), substances that emit light of colors such as blue, purple, blue-purple, green, yellow-green, yellow, orange, and red can be appropriately used. When a plurality of light-emitting layers are provided, different light-emitting substances can be used for each light-emitting layer to produce a structure that emits different light colors (for example, white light emission obtained by combining complementary light-emitting colors). Furthermore, a stacked structure in which one light-emitting layer contains different light-emitting substances may be used.

[0103] The light-emitting layers (113, 113a, 113b) may contain one or more organic compounds (host materials, etc.) in addition to the light-emitting substance (guest material).

[0104] Specifically, the structure described with reference to FIG. 1B in Embodiment 1 can be used for the light-emitting layer 113. In the light-emitting layer 113, the host material 118 is present in the largest amount by weight, and the guest material 119 (phosphorescent compound) is dispersed in the host material 118. The T1 level of the host material 118 (organic compound 118_1 and organic compound 118_2) of the light-emitting layer 113 is preferably higher than the T1 level of the guest material of the light-emitting layer 113 (guest material 119).

[0105] As the organic compound 118_1, a material having a higher electron transporting property than a hole transporting property can be used. −６cm ２ Preferably, the material has an electron mobility of 1 / Vs or more. Examples of materials that readily accept electrons (materials with electron transport properties) include compounds having a π-electron-deficient heteroaromatic ring skeleton, such as nitrogen-containing heteroaromatic compounds, and zinc- or aluminum-based metal complexes. Examples of compounds having a π-electron-deficient heteroaromatic ring skeleton include oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, phenanthroline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and triazine derivatives. Examples of zinc- or aluminum-based metal complexes include metal complexes having a quinoline ligand, a benzoquinoline ligand, an oxazole ligand, or a thiazole ligand.

[0106] Specifically, for example, tris(8-quinolinolato)aluminum(III) (abbreviation: Alq), tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq), ３ ), bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq ２Examples of suitable metal complexes include those having a quinoline skeleton or a benzoquinoline skeleton, such as bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), and bis(8-quinolinolato)zinc(II) (abbreviation: Znq). Other examples include metal complexes having an oxazole or thiazole ligand, such as bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO) and bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ). In addition to metal complexes, 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-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 9-[4-(4,5-diphenyl-4H-1,2,4-triazol-3-yl)phenyl]-9H-carbazole (abbreviation: CzTAZ1), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzoimide) heterocyclic compounds such as 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), bathophenanthroline (abbreviation: BPhen), and bathocuproine (abbreviation: BCP); -II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4-(3,6-diphenyl-9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 2-[3-(3,9'-bi-9H-cal 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazole-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzCzPDBq), 4,6-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-carbazole-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzCzPDBq), 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazole ... heterocyclic compounds having a diazine skeleton such as 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}pyrimidine (abbreviation: 4,6mCzP2Pm); heterocyclic compounds having a triazine skeleton such as 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn); heterocyclic compounds having a pyridine skeleton 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); and heteroaromatic compounds such as 4,4′-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs). Among the heterocyclic compounds described above, heterocyclic compounds having a triazine skeleton, a diazine (pyrimidine, pyrazine, pyridazine) skeleton, or a pyridine skeleton are preferred because they are stable and reliable. Furthermore, heterocyclic compounds having such skeletons have high electron transport properties and contribute to reducing driving voltage. Polymer compounds such as poly(2,5-pyridinediyl) (abbreviated as PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviated as PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviated as PF-BPy) can also be used. The substances described here are mainly 1×10, −６ cm ２Note that any substance other than those mentioned above may be used as long as it has a higher electron transporting property than a hole transporting property.

[0107] The organic compound 118_2 is preferably a combination capable of forming an exciplex with the organic compound 118_1. Specifically, it preferably has a highly donor skeleton such as a π-electron-rich heteroaromatic ring skeleton or an aromatic amine skeleton. Examples of compounds having a π-electron-rich heteroaromatic ring skeleton include heteroaromatic compounds such as dibenzothiophene derivatives, dibenzofuran derivatives, and carbazole derivatives. In this case, it is preferable to select the organic compound 118_1, the organic compound 118_2, and the guest material 119 (phosphorescent compound) so that the emission peak of the exciplex formed by the organic compound 118_1 and the organic compound 118_2 overlaps with the absorption band of the triplet MLCT (Metal to Ligand Charge Transfer) transition of the guest material 119 (phosphorescent compound), more specifically, with the absorption band located at the longest wavelength. This allows for a light-emitting device with dramatically improved emission efficiency. However, when a thermally activated delayed fluorescent material is used instead of a phosphorescent compound, the absorption band located at the longest wavelength is preferably a singlet absorption band.

[0108] Further, as the organic compound 118_2, the following hole transporting materials can be used.

[0109] As the hole transporting material, a material having a higher hole transporting property than electron transporting property can be used. −６ cm ２ The hole transport material is preferably a material having a hole mobility of 1 / Vs or more. Specifically, aromatic amines, carbazole derivatives, aromatic hydrocarbons, stilbene derivatives, etc. may be used. The hole transport material may also be a polymer compound.

[0110] Specific examples of these materials with high hole transport properties include aromatic amine compounds such as N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 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), and 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B).

[0111] Specific examples of the carbazole derivative include 3-[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA1), 3,6-bis[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA2), and 3,6-bis[N-(4-diphenylaminophenyl)-N-(1-naphthyl)amino]-9-phenylcarbazole (abbreviation: PCzTP N2), 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), 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1), and the like.

[0112] Other carbazole derivatives that can be used include 4,4'-di(N-carbazolyl)biphenyl (abbreviation: CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviation: TCPB), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), and 1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene.

[0113] Examples of aromatic hydrocarbons include 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 2-tert-butyl-9,10-di(1-naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 2-tert-butyl-9,10-bis(4-phenylphenyl)anthracene (abbreviation: t-BuDBA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 9,10-diphenylanthracene (abbreviation: DPAnth), 2-tert-butylanthracene (abbreviation: t-BuAnth), 9,10-bis(4-methyl-1-naphthyl)anthracene (abbreviation: DMNA), 2-tert-butyl-9,10-bis[2-(1- Examples of aromatic hydrocarbons having 14 to 42 carbon atoms include anthracene, tetracene, rubrene, perylene, and 2,5,8,11-tetra(tert-butyl)perylene. Examples of aromatic hydrocarbons that can be used include pentacene, coronene, and the like. In this way, 1 x 10 −６ cm ２ A hole mobility of 1 / Vs or more is preferred.

[0114] The aromatic hydrocarbon may have a vinyl skeleton. Examples of aromatic hydrocarbons having a vinyl skeleton include 4,4′-bis(2,2-diphenylvinyl)biphenyl (abbreviation: DPVBi) and 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviation: DPVPA).

[0115] Alternatively, polymer compounds 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), or poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD) can also be used.

[0116] Furthermore, examples of materials with high hole transport properties 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), 4,4′,4″-tris(carbazol-9-yl)triphenylamine (abbreviation: TCTA), 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'-bis(9,9'-spirobi[9H-fluoren]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl N-(9,9-dimethyl-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), N-(9,9-spirobi[9 H-fluoren]-2-yl)-N,N'N'-triphenyl-1,4-phenylenediamine (abbreviation: DPASF), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 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 amine (abbreviation: PCA3B), N-(9,9-diphenyl-9H-fluoren-2-yl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: PCAFLP(2)), N-(9,9-diphenyl-9H-fluoren-2-yl)-N,9-diphenyl-9H-carbazole-2-amine (abbreviation: PCAFLP(2)-02), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole-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), 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-fluoren]-2-amine (abbreviation: PCBASF), N-(9,9-spi N,N'-diphenyl-N,N'-bis(4-diphenylaminophenyl)spirobi[9H-fluorene]-2,7-diamine (abbreviation: DPA2SF), N-[4-(9H-carbazol-9-yl)phenyl]-N-(4-phenyl)phenylaniline (abbreviation: YGA1BP), N,N'-bis[4-(carbazol-9-yl)phenyl]-N,N'-diphenyl-9,9-dimethylfluorene-2,Aromatic amine compounds such as 7-diamine (abbreviation: YGA2F) can also be used. In addition, 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 9-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]phenanthrene (abbreviation: PCPPn), 3,3′-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 3,6-bis(3,5-diphenylfuran) and the like can also be used. 3,6-di(9H-carbazol-9-yl)-9-phenylcarbazole (abbreviation: CzTP), 3,6-di(9H-carbazol-9-yl)-9-phenyl-9H-carbazole (abbreviation: PhCzGI), 2,8-di(9H-carbazol-9-yl)dibenzothiophene (abbreviation: CzDBT), 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-I Examples of compounds that can be used include amine compounds such as 4,4',4"-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II), 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), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), and 4-[3-(triphenylen-2-yl)phenyl]dibenzothiophene (abbreviation: mDBTPTp-II), carbazole compounds, thiophene compounds, furan compounds, fluorene compounds, triphenylene compounds, and phenanthrene compounds. Among the above-mentioned compounds, compounds having a pyrrole skeleton, a furan skeleton, a thiophene skeleton, or an aromatic amine skeleton are preferred because they are stable and reliable. Furthermore, compounds having such skeletons have high hole transport properties and contribute to reducing driving voltage.

[0117] Furthermore, a substance that exhibits fluorescent emission (fluorescent substance) can be further used in the light-emitting layer. In this case, the excitation energy of the phosphorescent substance in the light-emitting layer is transferred to the fluorescent substance, resulting in light emission. The fluorescent substance allows transition from the singlet excited state to the singlet ground state, so its excitation lifetime (emission lifetime) is shorter than that of the phosphorescent substance. Therefore, by further using a fluorescent substance in the light-emitting layer, a stable and reliable light-emitting device can be fabricated.

[0118] Examples of fluorescent substances include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, naphthalene derivatives, etc. Fluorescent substances whose singlet excitation energy levels and triplet excitation energy levels are lower than the triplet excitation energy levels of the phosphorescent substance can be used.

[0119] Specific examples include 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2,2′-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4′-(10-phenyl-9-anthryl)biphenyl-4-yl]-2,2′-bipyridine (abbreviation: PAPP2BPy), N,N′-diphenyl-N,N′-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N′-bis(3-methylphenyl)-N,N′-bis[3-(9-phenyl-9 N,N'-bis[4-(9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA) , N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis(N,N',N'-triphenyl-1,4-phenyl) diamine) (abbreviation: DPABPA), N,N,N',N',N'',N'',N''',N'''-octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), Coumarin 30, N,N'-diphenyl-N,N'-(1,6-pyrene-diyl)bis[(6-phenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10PCA2Nbf(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02), and the like.

[0120] Also, 5,9-diphenyl-5,9-diaza-13b-boranaphtho[3,2,1-de]anthracene (abbreviation: DABNA1), 9-[(1,1′-diphenyl)-3-yl]-N,N,5,11-tetraphenyl-5,9-dihydro-5,9-diaza-13b-boranaphtho[3,2,1-de]anthracene-3-amine (abbreviation: DABNA2), 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl) -N,N-diphenyl-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborin-7-amine (abbreviation: DPhA-tBu4DABNA), 2,12-di(tert-butyl)-N,N,5,9-tetra(4-tert-butylphenyl)-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborin-7-amine (abbreviation: tBuDPhA-tBu4DABNA), 2,12-di(tert-butyl)-N,N,5,9-tetra(4-tert-butylphenyl)-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborin-7-amine (abbreviation: tBuDPhA-tBu4DABNA), N7,N7,N13,N13,5,9,11,15-octaphenyl-5H,9H,11H,15H-[1,4]benzazaborino[2,3,4-kl][1,4]benzazaborino[4',3',2':4,5][1,4]benzazaborino[ Condensed heteroaromatic compounds containing nitrogen and boron, such as [3,2-b]phenazaborine-7,13-diamine (abbreviation: v-DABNA) and 2-(4-tert-butylphenyl)benz[5,6]indolo[3,2,1-jk]benzo[b]carbazole (abbreviation: tBuPBibc), and in particular compounds having a diaza-boranaphtho-anthracene skeleton, are suitable for use because they have a narrow emission spectrum and can emit blue light with good color purity.

[0121] In addition to these, 9,10,11-tris[3,6-bis(1,1-dimethylethyl)-9H-carbazol-9-yl]-2,5,15,18-tetrakis(1,1-dimethylethyl)indolo[3,2,1-de]indolo[3',2',1':8,1][1,4]benzazaborino[2,3,4-kl]phenazaborine (abbreviation: BBCz-G), 9,11-bis[ Compounds having an indole skeleton such as [3,6-bis(1,1-dimethylethyl)-9H-carbazol-9-yl]-2,5,15,18-tetrakis(1,1-dimethylethyl)indolo[3,2,1-de]indolo[3′,2′,1′:8,1][1,4]benzazaborino[2,3,4-kl]phenazaborine (abbreviation: BBCz-Y) can be preferably used.

[0122] The light-emitting material contained in the light-emitting layer may be a thermally activated delayed fluorescence (TADF) material, such as a heterocyclic compound having a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring. Specific examples include 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), and 3-[4

[0023] bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthracene]-10'-one (abbreviation: ACRSA), etc. The heterocyclic compound has a π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring, and therefore has high electron transport properties and hole transport properties, making it preferable. Among the skeletons having a π-electron-deficient heteroaromatic ring, diazine skeletons (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton) or triazine skeletons are preferred because they are stable and reliable.Furthermore, among the skeletons having a π-electron-rich heteroaromatic ring, acridine skeleton, phenoxazine skeleton, thiophene skeleton, furan skeleton, and pyrrole skeleton are stable and reliable, so it is preferred to have one or more selected from these skeletons.Incidentally, as the pyrrole skeleton, indole skeleton, carbazole skeleton, and 3-(9-phenyl-9H-carbazol-3-yl)-9H-carbazole skeleton are particularly preferred.In addition, a substance in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded is particularly preferred because the donor property of the π-electron-rich heteroaromatic ring and the acceptor property of the π-electron-deficient heteroaromatic ring are both strong, and the difference between the singlet excitation energy level and the triplet excitation energy level is small. In addition, the compound having the above-mentioned diaza-boranaphtho-anthracene skeleton also functions as a thermally activated delayed fluorescence material, and is suitable because it can emit blue light with good color purity.

[0123] Alternatively, a thermally activated delayed fluorescent material may be used instead of a phosphorescent material. The thermally activated delayed fluorescent material has a small difference between the triplet excitation energy level and the singlet excitation energy level, and is a material that converts energy from the triplet excited state to the singlet excited state by reverse intersystem crossing. Therefore, the triplet excited state can be upconverted to the singlet excited state by a small amount of thermal energy (reverse intersystem crossing), and light emission (fluorescence) from the singlet excited state can be efficiently exhibited. In addition, conditions for efficiently obtaining thermally activated delayed fluorescence include an energy difference between the triplet excitation energy level and the singlet excitation energy level that is preferably greater than 0 eV and less than 0.2 eV, more preferably greater than 0 eV and less than 0.1 eV.

[0124] Examples of the guest material 119 (phosphorescent compound) include organometallic complexes or metal complexes of iridium, rhodium, or platinum, with platinum complexes being preferred. Platinum complexes having nitrogen-containing heterocyclic carbenes are also suitable. Organic iridium complexes, such as iridium orthometal complexes, may also be used. Examples of orthometalating ligands include 4H-triazole ligands, 1H-triazole ligands, imidazole ligands, pyridine ligands, pyrimidine ligands, pyrazine ligands, and isoquinoline ligands.

[0125] The organic compound 118_1, the organic compound 118_2, and the guest material 119 (phosphorescent compound) are preferably selected so that the guest material 119 has a LUMO level higher than that of the organic compound 118_1 and a HOMO level lower than that of the organic compound 118_2. This allows a light-emitting device with high emission efficiency to be driven at a low voltage.

[0126] The organic compound 118_1, the organic compound 118_2, and the guest material 119 (phosphorescent compound) are preferably selected so that the guest material 119 (phosphorescent compound) has a LUMO level higher than that of the organic compound 118_1 and a HOMO level higher than that of the organic compound 118_2. This allows a light-emitting device with high emission efficiency to be driven at a low voltage.

[0127] Furthermore, it is preferable to select the organic compound 118_1 and the guest material 119 (phosphorescent compound) so that the energy difference between the LUMO level of the organic compound 118_1 and the HOMO level of the guest material 119 (phosphorescent compound) is equal to or greater than the energy calculated from the absorption edge located at the longest wavelength among the absorption edges in the absorption spectrum of the guest material 119 (phosphorescent compound). This allows for a light-emitting device with high emission efficiency that can be driven at a low voltage.

[0128] The absorption edge located at the longest wavelength in the absorption spectrum can be determined by measuring the absorption spectrum of the target substance in a thin film state or in a thin film obtained by doping the target substance into a matrix material, and then obtaining a Tauc plot assuming direct transition. Alternatively, the absorption spectrum of a solution can be measured, a tangent line can be drawn at the half-maximum of the longest wavelength side of the peak or shoulder peak observed at the longest wavelength in the absorption spectrum, and the absorption edge can be calculated from the intersection of the tangent line with the horizontal axis (wavelength) or the baseline. The solvent for the solution is not particularly limited, but relatively low-polarity solvents such as toluene and chloroform are preferred.

[0129] The HOMO level and LUMO level values ​​used in this specification can be determined by electrochemical measurements, such as cyclic voltammetry (CV) and differential pulse voltammetry (DPV).

[0130] In cyclic voltammetry (CV) measurements, the values ​​of the HOMO level and the LUMO level (E) are determined by measuring the oxidation peak potential (E ｐａ ), and reduction peak potential (E ｐｃ In the measurement, the HOMO level is determined from potential scanning in the positive direction, and the LUMO level is determined from potential scanning in the negative direction. The scan rate in the measurement is 0.1 V / s.

[0131] A specific procedure for calculating the HOMO level and the LUMO level will be described. The oxidation peak potential (E ｐａ ), and reduction peak potential (E ｐｃ ) to obtain the standard redox potential (E ｏ ) (= (E ｐａ +E ｐｃ ) / 2) was calculated, and the potential energy (E ｘ ) to obtain the values ​​of the HOMO and LUMO levels (E) (=E ｘ -E ｏ ) can be calculated respectively.

[0132] The above shows the case where a reversible redox wave is obtained, but when an irreversible redox wave is obtained, the oxidation peak potential (E ｐａ The reduction peak potential (E ｐｃ ) and the standard redox potential (E ｏ ) to one decimal place. In addition, the reduction peak potential (E ｐｃ ) plus a certain value (0.1 eV) is taken as the oxidation peak potential (E ｐａ ) and the standard redox potential (E ｏ ) to one decimal place.

[0133] An example of a substance having an emission peak in the blue or green wavelength region is tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN]phenyl-κC}iridium(III) (abbreviation: Ir(mpptz-dmp) ３ ), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviation: Ir(Mptz) ３ ), tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviation: Ir(iPrptz-3b) ３ ), tris[3-(5-biphenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviation: Ir(iPr5btz) ３ ), organometallic iridium complexes having a 4H-triazole skeleton such as tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: Ir(Mptz1-mp) ３ ), tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: Ir(Prptz1-Me) ３ organometallic iridium complexes having a 1H-triazole skeleton, such as fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: Ir(iPrpim) ３ ), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: Ir(dmpimpt-Me) ３ organometallic iridium complexes having an imidazole skeleton, such as tris(2-{1-[2,6-bis(1-methylethyl)phenyl]-1H-imidazol-2-yl-κN}-4-cyanophenyl-κC) (abbreviation: CNImIr), tris[(6-tert-butyl-3-phenyl-2H-imidazo[4,5-b]pyrazin-1-yl-κC)phenyl-κC]iridium(III) (abbreviation: [Ir(cb)３ an organic iridium complex having a benzimidazolidene skeleton, such as bis[2-(4',6'-difluorophenyl)pyridinato-N,C ２’ ]iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridinato-N,C ２’ ]iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinato-N,C ２’} Iridium(III) picolinate (abbreviation: Ir(CF ３ ppy) ２ (pic)), bis[2-(4',6'-difluorophenyl)pyridinato-N,C ２’ Examples of suitable iridium complexes include organometallic iridium complexes having a phenylpyridine derivative as a ligand having an electron-withdrawing group, such as ]iridium(III) acetylacetonate (abbreviation: FIr(acac)), and platinum complexes such as (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-(4-tert-butyl-2-pyridinyl-κN)carbazole-2,1-diyl-κC1)platinum(II) (abbreviation: PtON-TBBI). Compounds in which some of the hydrogen atoms in these compounds have been replaced with deuterium atoms can also be used. Among the above-mentioned compounds, organometallic iridium complexes having a nitrogen-containing five-membered heterocyclic skeleton, such as a 4H-triazole skeleton, a 1H-triazole skeleton, or an imidazole skeleton, are particularly preferred because they have high triplet excitation energy and are highly reliable or luminous efficiency.

[0134] Furthermore, examples of substances having an emission peak in the green or yellow wavelength region include tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: Ir(mppm) ３ ), tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: Ir(tBuppm) ３ ), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: Ir(mppm) ２(acac)), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: Ir(tBuppm) ２ (acac)), (acetylacetonato)bis[4-(2-norbornyl)-6-phenylpyrimidinato]iridium(III) (abbreviation: Ir(nbppm) ２ (acac)), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: Ir(mpmppm) ２ (acac)), (acetylacetonato)bis{4,6-dimethyl-2-[6-(2,6-dimethylphenyl)-4-pyrimidinyl-κN]phenyl-κC}iridium(III) (abbreviation: Ir(dmppm-dmp) ２ (acac)), (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: Ir(dppm) ２ organometallic iridium complexes having a pyrimidine skeleton, such as (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III) (abbreviation: Ir(mppr-Me) ２ (acac)), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: Ir(mppr-iPr) ２ organometallic iridium complexes having a pyrazine skeleton, such as tris(2-phenylpyridinato-N,C(acac)), ２’ ) Iridium (III) (abbreviation: Ir(ppy) ３ ), bis(2-phenylpyridinato-N,C ２’ ) Iridium(III) acetylacetonate (abbreviation: Ir(ppy) ２ (acac)), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: Ir(bzq) ２ (acac)), tris(benzo[h]quinolinato)iridium(III) (abbreviation: Ir(bzq) ３ ), tris(2-phenylquinolinato-N,C ２’ ) Iridium (III) (abbreviation: Ir(pq)３ ), bis(2-phenylquinolinato-N,C ２’ ) Iridium(III) acetylacetonate (abbreviation: Ir(pq) ２ (acac)), [2-(4-d3-methyl-5-phenyl-2-pyridinyl-κN2)phenyl-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) (abbreviation: [Ir(5mppy-d ３ ) ２ (mdppy-d ３ ) )]), [2-methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy) ２ (mbfppy)]), tris{2-[5-(methyl-d3)-4-phenyl-2-pyridinyl-κN]phenyl-κC}iridium(III) (abbreviation: Ir(5m4dppy-d ３ ) ３ organometallic iridium complexes having a pyridine skeleton, such as bis(2,4-diphenyl-1,3-oxazolato-N,C) ２’ ) Iridium (III) acetylacetonate (abbreviation: Ir(dpo) ２ (acac)), bis{2-[4′-(perfluorophenyl)phenyl]pyridinato-N,C ２’} Iridium (III) acetylacetonate (abbreviation: Ir(p-PF-ph) ２ (acac)), bis(2-phenylbenzothiazolato-N,C ２’ ) Iridium(III) acetylacetonate (abbreviation: Ir(bt) ２ In addition to organometallic iridium complexes such as tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: Tb(acac) ３(Phen)), (2-{1-(5-tert-butylbiphenyl-2-yl)-4-[3-tert-butyl-5-(4-phenyl-2-pyridinyl-κN)phenyl-κC6]-2-benzimidazolyl-κN3}-4,6-di-tert-butylphenolato-κO)platinum(II) (abbreviation: Pt(tBudppymmtBubiz-tBubp)), and [2-(4-(3,5-di-tert-butylphenyl)-6-{3-[4-(5′-tert-butyl[1,1′:3′,1″-terphenyl]-2′-yl)-2-pyridinyl-κN]phenyl-κC2}-2-pyridinyl-κN)phenolato-κO]platinum(II) (abbreviation: Pt(4tButppppypyp-mmtBup)). Compounds in which some of the hydrogen atoms in these compounds are replaced with deuterium atoms can also be used. Among the above, organometallic iridium complexes having a pyrimidine skeleton are particularly preferred because of their outstanding reliability and luminous efficiency.

[0135] Furthermore, examples of substances having an emission peak in the yellow or red wavelength region include (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(III) (abbreviation: Ir(5mdppm) ２ (dibm)), bis[4,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: Ir(5mdppm) ２ (dpm)), bis[4,6-di(naphthalen-1-yl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: Ir(dpm) ２ organometallic iridium complexes having a pyrimidine skeleton, such as (acetylacetonato)bis(2,3,5-triphenylpyrazinato)iridium(III) (abbreviation: Ir(tppr) ２ (acac)), bis(2,3,5-triphenylpyrazinato)(dipivaloylmethanato)iridium(III) (abbreviation: Ir(tppr) ２ (dpm)), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: Ir(Fdpq) ２organometallic iridium complexes having a pyrazine skeleton, such as tris(1-phenylisoquinolinato-N,C(acac)); ２’ ) Iridium (III) (abbreviation: Ir(piq) ３ ), bis(1-phenylisoquinolinato-N,C ２’ ) Iridium(III) acetylacetonate (abbreviation: Ir(piq) ２ In addition to organometallic iridium complexes having a pyridine skeleton such as (acac)), platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrinplatinum(II) (abbreviation: PtOEP), tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: Eu(DBM)), ３ (Phen)), tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: Eu(TTA) ３ Examples of such rare earth metal complexes include rare earth metal complexes such as (Phen). Compounds in which some of the hydrogen atoms in these compounds are replaced with deuterium atoms can also be used. Among the above, organometallic iridium complexes having a pyrimidine skeleton are particularly preferred because of their outstanding reliability and luminous efficiency. Furthermore, organometallic iridium complexes having a pyrazine skeleton can emit red light with good chromaticity.

[0136] The light-emitting material contained in the light-emitting layer 113 is a material capable of converting triplet excitation energy into light emission. Examples of materials capable of converting triplet excitation energy into light emission include, in addition to phosphorescent compounds, thermally activated delayed fluorescence (TADF) materials. Therefore, the term "phosphorescent compound" may be interpreted as "thermally activated delayed fluorescence material." Note that a thermally activated delayed fluorescence material is a material that has a small difference between the triplet excitation energy level and the singlet excitation energy level and has the function of converting energy from a triplet excited state to a singlet excited state by reverse intersystem crossing. Therefore, a triplet excited state can be upconverted to a singlet excited state by a small amount of thermal energy (reverse intersystem crossing), and light emission (fluorescence) from the singlet excited state can be efficiently exhibited. In addition, conditions for efficiently obtaining thermally activated delayed fluorescence include an energy difference between the triplet excitation energy level and the singlet excitation energy level being preferably greater than 0 eV and less than or equal to 0.2 eV, more preferably greater than 0 eV and less than or equal to 0.1 eV.

[0137] When the thermally activated delayed fluorescent material is composed of one type of material, for example, the following material can be used.

[0138] First, there are derivatives such as fullerene, acridine derivatives such as proflavine, eosin, etc. Furthermore, there are metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), palladium (Pd), etc. Examples of the metal-containing porphyrins include protoporphyrin-tin fluoride complexes (SnF ２ (Proto IX)), mesoporphyrin-tin fluoride complex (SnF ２ (Meso IX)), hematoporphyrin-tin fluoride complex (SnF ２ (Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (SnF ２ (Copro III-4Me)), octaethylporphyrin-tin fluoride complex (SnF ２(OEP)), etioporphyrin-tin fluoride complex (SnF ２ (Etio I)), octaethylporphyrin-platinum chloride complex (PtCl ２ (OEP)) and the like.

[0139] In addition, as the thermally activated delayed fluorescence material composed of one kind of material, heterocyclic compounds having π-electron rich heteroaromatic ring and π-electron deficient heteroaromatic ring can also be used.Specifically, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4- Examples of the heterocyclic compound include (5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviation: DMAC-DPS), and 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthracene]-10'-one (abbreviation: ACRSA). The heterocyclic compound has a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring, and therefore has high electron-transporting and hole-transporting properties, making it preferable. Among the skeletons having a π-electron-deficient heteroaromatic ring, diazine skeletons (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton) or triazine skeletons are preferred because they are stable and reliable.Furthermore, among the skeletons having a π-electron-rich heteroaromatic ring, acridine skeleton, phenoxazine skeleton, thiophene skeleton, furan skeleton, and pyrrole skeleton are stable and reliable, so it is preferred to have one or more selected from these skeletons.Incidentally, as the pyrrole skeleton, indole skeleton, carbazole skeleton, and 3-(9-phenyl-9H-carbazol-3-yl)-9H-carbazole skeleton are particularly preferred.In addition, a substance in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded is particularly preferable because the donor property of the π-electron-rich heteroaromatic ring and the acceptor property of the π-electron-deficient heteroaromatic ring are both strong, and the difference between the singlet excitation energy level and the triplet excitation energy level is small.

[0140] The light-emitting layer 113 can also be configured with two or more layers. For example, when the light-emitting layer 113 is formed by stacking a first light-emitting layer and a second light-emitting layer in this order from the hole-transporting layer side, a structure in which a substance having hole-transporting properties is used as a host material for the first light-emitting layer and a substance having electron-transporting properties is used as a host material for the second light-emitting layer can be used. Furthermore, the light-emitting materials of the first light-emitting layer and the second light-emitting layer may be the same or different materials, and may be materials that have the function of emitting light of the same color or materials that have the function of emitting light of different colors. By using light-emitting materials that have the function of emitting light of different colors in the two light-emitting layers, multiple light emissions can be obtained simultaneously. In particular, it is preferable to select light-emitting materials for each light-emitting layer so that the light emitted by the two light-emitting layers becomes white.

[0141] The light-emitting layer 113 may contain a material other than the host material 118 and the guest material 119 .

[0142] The light-emitting layer 113 can be formed by a vapor deposition method (including a vacuum deposition method), an inkjet method, a coating method, gravure printing, etc. In addition to the materials described above, the light-emitting layer 113 may contain an inorganic compound such as a quantum dot or a polymer compound (an oligomer, a dendrimer, a polymer, etc.).

[0143] <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 organic compound layer (103, 103a, 103b), and is a layer that contains an organic acceptor material and a material with high hole injection properties.

[0144] The hole injection layer (111, 111a, 111b) has the function of promoting hole injection by reducing the hole injection barrier from one of the pair of electrodes (the first electrode 101 or the second electrode 102). It is formed, for example, from a transition metal oxide, a phthalocyanine derivative, or an aromatic amine. Examples of transition metal oxides include molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide. Examples of phthalocyanine derivatives include phthalocyanine and metal phthalocyanine. Examples of aromatic amines include benzidine derivatives and phenylenediamine derivatives. Polymer compounds such as polythiophene and polyaniline can also be used, and a representative example is poly(ethylenedioxythiophene) / polystyrene sulfonic acid, which is a self-doped polythiophene.

[0145] The hole injection layer (111, 111a, 111b) may be a layer containing a composite material of a hole transporting material and a material exhibiting electron accepting properties. Alternatively, a stack of a layer containing a material exhibiting electron accepting properties and a layer containing a hole transporting material may be used. Charges can be exchanged between these materials in a steady state or under the presence of an electric field. Examples of materials exhibiting electron accepting properties include organic acceptors such as quinodimethane derivatives, chloranil derivatives, and hexaazatriphenylene derivatives. Specifically, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F ４ The compound having an electron-withdrawing group (a halogen group or a cyano group), such as hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviated as HAT-CN), is preferably a compound having an electron-withdrawing group (a halogen group or a cyano group), such as hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviated as HAT-CN). Alternatively, a transition metal oxide, such as an oxide of a metal from Group 4 to Group 8, can be used. Specific examples include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among these, molybdenum oxide is preferred because it is stable in the atmosphere, has low hygroscopicity, and is easy to handle.

[0146] As the hole transporting material, a material having a higher hole transporting property than electron transporting property can be used. −６ cm ２ It is preferable that the material has a hole mobility of 1 / Vs or more. Specifically, aromatic amines, carbazole derivatives, aromatic hydrocarbons, stilbene derivatives, and the like, which are listed as hole-transporting materials that can be used for the light-emitting layer 113, can be used. The hole-transporting material may also be a polymer compound.

[0147] <Hole Transport Layer> The hole transport layer (112, 112a, 112b) is a layer containing a hole transport material, and the hole transport materials exemplified as the material for the hole injection layer (111, 111a, 111b) can be used. The hole transport layer (112, 112a, 112b) has a function of transporting holes injected into the hole injection layer (111, 111a, 111b) to the light-emitting layer (113, 113a, 113b), and therefore preferably has a HOMO level that is the same as or close to the HOMO level of the hole injection layer (111, 111a, 111b).

[0148] The hole transport material is 1×10 −６ cm ２ It is preferable that the material be a substance having a hole mobility of 1 / Vs or more. However, other substances may be used as long as they have a higher hole transporting property than electron transporting property. Note that the layer containing the substance having a high hole transporting property may be a single layer or may be a stack of two or more layers containing the above-mentioned substances.

[0149] <Electron Transport Layer> The electron transport layer (114, 114a, 114b) has a function of transporting electrons injected from the other of the pair of electrodes (the first electrode 101 or the second electrode 102) via the electron injection layer (115, 115a, 115b) to the light-emitting layer 113. As the electron-transporting material, a material having a higher electron transporting property than a hole transporting property can be used, and −６ cm ２ / Vs or more. Compounds that readily accept electrons (materials having electron transport properties) include compounds having a π-electron-deficient heteroaromatic ring skeleton, such as nitrogen-containing heteroaromatic compounds, and metal complexes. Specific examples include metal complexes having a quinoline ligand, a benzoquinoline ligand, an oxazole ligand, or a thiazole ligand, which are listed as electron transport materials that can be used in the light-emitting layer 113. Other examples include oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, phenanthroline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and triazine derivatives. The electron transport materials may have a specific conductivity of 1×10 −６ cm ２ It is preferable that the electron transport layer is a substance having an electron mobility of 1 / Vs or more. Note that any substance other than the above may be used as the electron transport layer as long as it has a higher electron transporting property than hole transporting property. The electron transport layer (114, 114a, 114b) may be a single layer or may be a stack of two or more layers made of the above substances.

[0150] Furthermore, a layer for controlling the movement of electron carriers may be provided between the electron transport layer (114, 114a, 114b) and the light-emitting layer (113, 113a, 113b). This layer is made by adding a small amount of a substance with high electron trapping properties to a material with high electron transport properties as described above, and by suppressing the movement of electron carriers, it becomes possible to adjust the carrier balance. Such a configuration is highly effective in suppressing problems (e.g., a reduction in device life) caused by electrons penetrating the light-emitting layer.

[0151] <Electron Injection Layer> The electron injection layer (115, 115a, 115b) has a function of promoting electron injection by reducing the electron injection barrier from the second electrode 102, and for example, a Group 1 metal, a Group 2 metal, or an oxide, halide, or carbonate thereof can be used. In addition, a composite material of the above-mentioned electron transporting material and a material that exhibits electron donating properties can also be used. Examples of materials that exhibit electron donating properties include Group 1 metals, Group 2 metals, or oxides thereof. Specifically, lithium fluoride (LiF), sodium fluoride (NaF), cesium fluoride (CsF), calcium fluoride (CaF ２ ), lithium oxide (Li ２ Alkali metals, alkaline earth metals, or compounds thereof such as erbium fluoride (ErF ３ A rare earth metal compound such as ZnO, ZnS, ZnO, ZnSe ...

[0152] The electron injection layer (115, 115a, 115b) may also be formed using a composite material obtained by mixing an organic compound and an electron donor (donor). Such composite materials have 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, for example, the substances constituting the electron transport layer 114 (metal complexes, heteroaromatic compounds, etc.) described above can be used. The electron donor is a substance that exhibits electron donating properties to the organic compound. Specifically, alkali metals, alkaline earth metals, or rare earth metals are preferred, such as lithium, sodium, cesium, magnesium, calcium, erbium, and ytterbium. Alkali metal oxides or 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.

[0153] The light-emitting layer, hole injection layer, hole transport layer, electron transport layer, and electron injection layer can be formed by vapor deposition (including vacuum vapor deposition), inkjet printing, coating, gravure printing, etc. In addition to the materials described above, the light-emitting layer, hole injection layer, hole transport layer, electron transport layer, and electron injection layer may be made of inorganic compounds such as quantum dots or polymeric compounds (oligomers, dendrimers, polymers, etc.).

[0154] The quantum dots may be colloidal quantum dots, alloy quantum dots, core-shell quantum dots, core quantum dots, etc. Quantum dots containing elements from groups 2 and 16, 13 and 15, 13 and 17, 11 and 17, or 14 and 15 may also be used. Quantum dots containing elements such as cadmium (Cd), selenium (Se), zinc (Zn), sulfur (S), phosphorus (P), indium (In), tellurium (Te), lead (Pb), gallium (Ga), arsenic (As), or aluminum (Al) may also be used.

[0155] <<Pair of Electrodes>> The first electrode 101 and the second electrode 102 function as an anode or a cathode of the light-emitting device. The first electrode 101 and the second electrode 102 can be formed using a metal, an alloy, a conductive compound, a mixture thereof, a stack thereof, or the like.

[0156] One of the first electrode 101 and the second electrode 102 is preferably formed of a conductive material that has a light-reflecting function. Examples of the conductive material include aluminum (Al) and alloys containing Al. Examples of alloys containing Al include alloys containing Al and L (L represents one or more of titanium (Ti), neodymium (Nd), nickel (Ni), and lanthanum (La)), such as alloys containing Al and Ti, or alloys containing Al, Ni, and La. Aluminum has low resistance and high light reflectivity. Furthermore, aluminum is abundant in the earth's crust and is inexpensive, so the use of aluminum can reduce the manufacturing cost of light-emitting devices. Alternatively, silver (Ag) or an alloy containing Ag and N (N represents one or more of yttrium (Y), Nd, magnesium (Mg), ytterbium (Yb), Al, Ti, gallium (Ga), zinc (Zn), indium (In), tungsten (W), manganese (Mn), tin (Sn), iron (Fe), Ni, copper (Cu), palladium (Pd), iridium (Ir), or gold (Au)) may be used. Examples of alloys containing silver include alloys containing silver, palladium, and copper, alloys containing silver and copper, alloys containing silver and magnesium, alloys containing silver and nickel, alloys containing silver and gold, and alloys containing silver and ytterbium. Other transition metals that can be used include tungsten, chromium (Cr), molybdenum (Mo), copper, and titanium.

[0157] Furthermore, light emitted from the light-emitting layer is extracted through one or both of the first electrode 101 and the second electrode 102. Therefore, at least one of the first electrode 101 and the second electrode 102 is preferably formed from a conductive material that has a light-transmitting function. The conductive material has a visible light transmittance of 40% to 100%, preferably 60% to 100%, and a resistivity of 1×10 −２Examples include conductive materials with a resistance of Ω·cm or less.

[0158] The first electrode 101 and the second electrode 102 may be formed of a conductive material that has a function of transmitting and reflecting light. The conductive material has a reflectance of 20% to 80%, preferably 40% to 70%, for visible light (for example, light of a predetermined wavelength in the range of 400 nm to less than 750 nm), and a resistivity of 1×10 −２ Examples of suitable conductive materials include those with a resistivity of Ω·cm or less. For example, the conductive layer can be formed using one or more conductive metals, alloys, conductive compounds, etc. Specifically, metal oxides such as indium tin oxide (ITO), indium tin oxide containing silicon oxide (ITSO), indium zinc oxide (ITO), indium tin oxide containing titanium, indium titanium oxide, and indium oxide containing tungsten oxide and zinc oxide can be used. Alternatively, a thin metal film that is light-transmitting (preferably, a thickness of 1 nm to 30 nm) can be used. Examples of suitable metals include Ag, alloys of Ag and Al, Ag and Mg, Ag and Au, and Ag and Yb.

[0159] In this specification and the like, the material having the function of transmitting light is a material that has the function of transmitting visible light and is conductive, and includes, for example, oxide conductors such as ITO as described above, as well as oxide semiconductors or organic conductors containing organic substances. Examples of organic conductors containing organic substances include composite materials obtained by mixing an organic compound with an electron donor (donor), and composite materials obtained by mixing an organic compound with an electron acceptor. In addition, inorganic carbon-based materials such as graphene may also be used. The resistivity of the material is preferably 1×10 ５ Ω cm or less, more preferably 1×10 ４ It is Ω·cm or less.

[0160] Alternatively, one or both of the first electrode 101 and the second electrode 102 may be formed by stacking a plurality of the above-mentioned materials.

[0161] Furthermore, in order to improve light extraction efficiency, a material having a higher refractive index than an electrode having a light-transmitting function can be formed in contact with the electrode. Such a material can be a material that transmits visible light and has a conductive or non-conductive property. Examples of such a material include oxide semiconductors and organic materials in addition to the oxide conductors described above. Examples of organic materials include the materials exemplified for the light-emitting layer, hole injection layer, hole transport layer, electron transport layer, and electron injection layer. Carbon materials or thin metal films that transmit light can also be used, and a structure in which multiple layers of several nanometers to several tens of nanometers are stacked can also be used.

[0162] When the first electrode 101 or the second electrode 102 functions as a cathode, it is preferable that the first electrode 101 or the second electrode 102 be made of a material having a small work function (3.8 eV or less). For example, elements belonging to Group 1 or 2 of the periodic table (alkali metals such as lithium, sodium, and cesium, alkaline earth metals such as calcium and strontium, magnesium, etc.), alloys containing these elements (e.g., Ag and Mg, Al and Li), rare earth metals such as europium (Eu) and Yb, alloys containing these rare earth metals, alloys containing aluminum, and alloys containing silver can be used.

[0163] When the first electrode 101 or the second electrode 102 is used as an anode, it is preferable to use a material having a large work function (4.0 eV or more).

[0164] The first electrode 101 and the second electrode 102 may be a stack of a conductive material having a light reflecting function and a conductive material having a light transmitting function. In this case, the first electrode 101 and the second electrode 102 preferably have a function of adjusting the optical distance between the first electrode 101 and the second electrode 102 so that light of a desired wavelength from each light-emitting layer can be resonated and the light of that wavelength can be intensified.

[0165] The first electrode 101 and the second electrode 102 can be formed by a sputtering method, a vapor deposition method, a printing method, a coating method, a molecular beam epitaxy (MBE) method, a CVD method, a pulsed laser deposition method, an atomic layer deposition (ALD) method, or the like, as appropriate.

[0166] <Charge Generation Layer> The charge generation layer 106 has a function of injecting electrons into the organic compound layer 103a and injecting holes into the organic compound 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. By forming the charge generation layer 106 using a P-type layer, an electron injection buffer layer, or an electron relay layer, or a stack of these layers, an increase in driving voltage when organic compound layers are stacked can be suppressed.

[0167] 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.

[0168] 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.

[0169] 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.

[0170] Although FIG. 2D shows a structure in which two organic compound layers 103 are stacked, a stack structure of three or more organic compound layers may be formed by providing a charge generating layer between different organic compound layers.

[0171] 2A to 2E , 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.

[0172] 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), and the like. The organic compounds described in Embodiment 1 can also be used.

[0173] <<Substrate>> The light-emitting device according to one embodiment of the present invention can be manufactured over a substrate made of glass, plastic, etc. The order of manufacturing the light-emitting device on the substrate can be a structure in which layers are stacked in order from the first electrode 101 side or a structure in which layers are stacked in order from the second electrode 102 side.

[0174] Note that, as a substrate on which a light-emitting device according to one embodiment of the present invention can be formed, for example, glass, quartz, or plastic can be used. A flexible substrate may also be used. A flexible substrate is a substrate that can be bent (flexible), and examples thereof include a plastic substrate made of polycarbonate or polyarylate. Films, inorganic vapor-deposited films, and the like can also be used. Note that other materials can also be used as long as they function as a support in the manufacturing process of the light-emitting device and the optical element. Alternatively, a material that has a function of protecting the light-emitting device and the optical element can be used.

[0175] For example, in this specification, a light-emitting device can be formed using various substrates. The type of substrate is not particularly limited. Examples of such substrates include semiconductor substrates (e.g., single-crystal substrates or silicon substrates), SOI substrates, glass substrates, quartz substrates, plastic substrates, metal substrates, stainless steel substrates, substrates having stainless steel foil, tungsten substrates, substrates having tungsten foil, flexible substrates, laminated films, cellulose nanofibers (CNF) containing fibrous materials, paper, and base films. Examples of glass substrates include barium borosilicate glass, aluminoborosilicate glass, and soda-lime glass. Examples of flexible substrates, laminated films, and base films include the following: For example, plastics such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), and polytetrafluoroethylene (PTFE). Another example is acrylic resin. Another example is polypropylene, polyester, polyvinyl fluoride, or polyvinyl chloride. Other examples include resins such as polyamide resin, polyimide resin, aramid resin, and epoxy resin, inorganic vapor deposition films, and papers.

[0176] Alternatively, a flexible substrate may be used as the substrate, and the light-emitting device may be formed directly on the flexible substrate. Alternatively, a release layer may be provided between the substrate and the light-emitting device. The release layer can be used to separate the light-emitting device from the substrate after it has been partially or entirely completed and transfer it to another substrate. In this case, the light-emitting device can be transferred to a substrate with poor heat resistance or a flexible substrate. The release layer may be, for example, a laminated structure of inorganic films such as a tungsten film and a silicon oxide film, or a structure in which a resin film such as polyimide is formed on a substrate.

[0177] That is, a light-emitting device may be formed using a certain substrate, and then the light-emitting device may be transferred to another substrate, and the light-emitting device may be disposed on the other substrate. In addition to the above-mentioned substrates, examples of the substrate onto which the light-emitting device may be transferred include a cellophane substrate, a stone substrate, a wood substrate, a cloth substrate (including natural fibers (silk, cotton, linen), synthetic fibers (nylon, polyurethane, polyester), or recycled fibers (acetate, cupra, rayon, recycled polyester)), a leather substrate, or a rubber substrate. By using these substrates, a light-emitting device that is durable, highly heat-resistant, lightweight, or thin can be obtained.

[0178] Alternatively, a field effect transistor (FET) may be formed on the substrate, and a light emitting device may be fabricated on an electrode electrically connected to the FET, thereby fabricating an active matrix display device in which the FET controls the driving of the light emitting device.

[0179] Note that one embodiment of the present invention has been described in this embodiment. Alternatively, another embodiment of the present invention will be described. However, one embodiment of the present invention is not limited thereto. That is, various embodiments of the present invention are described in this embodiment and the other embodiments, and therefore one embodiment of the present invention is not limited to a specific embodiment. For example, although an example in which the present invention is applied to a light-emitting device has been described as one embodiment of the present invention, one embodiment of the present invention is not limited thereto. For example, depending on the circumstances or the situation, one embodiment of the present invention does not need to be applied to a light-emitting device. Alternatively, for example, one embodiment of the present invention has an example in which a first organic compound, a second organic compound, and a guest material capable of converting triplet excitation energy into light emission are included, and the LUMO level of the first organic compound is lower than that of the second organic compound, and the HOMO level of the first organic compound is lower than that of the second organic compound. However, one embodiment of the present invention is not limited thereto. In some cases or depending on the circumstances, in one embodiment of the present invention, for example, the LUMO level of the first organic compound does not have to be lower than the LUMO level of the second organic compound. Alternatively, the HOMO level of the first organic compound does not have to be lower than the HOMO level of the second organic compound. Alternatively, for example, although an example in which the first organic compound and the second organic compound form an exciplex is described in one embodiment of the present invention, this embodiment is not limited thereto. Alternatively, in some cases or depending on the circumstances, in one embodiment of the present invention, for example, the first organic compound and the second organic compound do not have to form an exciplex. Alternatively, for example, although an example in which the LUMO level of the guest material is higher than the LUMO level of the first organic compound and the HOMO level of the guest material is lower than the HOMO level of the second organic compound is described in one embodiment of the present invention, this embodiment is not limited thereto. In some cases or depending on the situation, in one embodiment of the present invention, for example, the LUMO level of the guest material may not be higher than the LUMO level of the first organic compound, or the HOMO level of the guest material may not be lower than the HOMO level of the second organic compound.

[0180] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0181] 3A and 3B , a light-emitting device is configured by forming a plurality of the light-emitting devices described in the above embodiments over an insulating layer 175. In this embodiment, a light-emitting device according to one embodiment of the present invention will be described in detail.

[0182] The light emitting device 1000 has a pixel section 177 in which a plurality of pixels 178 are arranged in a matrix. The pixel 178 has a sub-pixel 110R, a sub-pixel 110G, and a sub-pixel 110B.

[0183] In this specification and the like, matters common to, for example, the subpixel 110R, the subpixel 110G, and the subpixel 110B may be described by referring to the subpixel 110. Furthermore, for components distinguished by alphabets, matters common to the corresponding structures may be described by using symbols without the alphabets.

[0184] The sub-pixel 110R emits red light, the sub-pixel 110G emits green light, and the sub-pixel 110B emits blue light. This allows an image to be displayed in the pixel portion 177. Note that in this embodiment, sub-pixels of three colors, red (R), green (G), and blue (B), are described as an example, but the present invention is not limited to this configuration. That is, combinations of sub-pixels of other colors may also be used. For example, the number of sub-pixels is not limited to three, and may be four or more. Examples of four sub-pixels include sub-pixels of four colors: R, G, B, and white (W); sub-pixels of four colors: R, G, B, and yellow (Y); and sub-pixels of R, G, B, and infrared (IR).

[0185] In this specification, the row direction may be referred to as the X direction, and the column direction may be referred to as the Y direction. The X direction and the Y direction intersect, for example, perpendicularly.

[0186] 3A shows an example in which subpixels of different colors are arranged side by side in the X direction, and subpixels of the same color are arranged side by side in the Y direction. Note that subpixels of different colors may also be arranged side by side in the Y direction, and subpixels of the same color may also be arranged side by side in the X direction.

[0187] A connection portion 140 and a region 141 may be provided outside the pixel portion 177. For example, the region 141 may be provided between the pixel portion 177 and the connection portion 140. An organic compound layer 103 is provided in the region 141. In addition, a conductive layer 151C is provided in the connection portion 140.

[0188] 3A shows an example in which the region 141 and the connection portion 140 are located on the right side of the pixel portion 177, but the positions of the region 141 and the connection portion 140 are not particularly limited. The region 141 and the connection portion 140 may be singular or plural.

[0189] 3B is an example of a cross-sectional view taken along dashed line A1-A2 in FIG. 3A. As shown in FIG. 3B, the light-emitting device 1000 includes an insulating layer 171, a conductive layer 172 on the insulating layer 171, an insulating layer 173 on the insulating layer 171 and on the conductive layer 172, an insulating layer 174 on the insulating layer 173, and an insulating layer 175 on the insulating layer 174. The insulating layer 171 may be provided on a substrate (not shown). The insulating layers 175, 174, and 173 have openings that reach the conductive layer 172, and a plug 176 is provided to fill the opening.

[0190] In the pixel section 177, the light-emitting device 130 is provided on the insulating layer 175 and the plug 176. A protective layer 131 is provided to cover the light-emitting device 130. The substrate 120 is bonded to the protective layer 131 by a resin layer 122. An inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 may be provided between adjacent light-emitting devices 130.

[0191] 3B shows multiple cross sections of the inorganic insulating layer 125 and the insulating layer 127, it is preferable that the inorganic insulating layer 125 and the insulating layer 127 are connected to one another when the light-emitting device 1000 is viewed from above. That is, the inorganic insulating layer 125 and the insulating layer 127 are insulating layers having openings on the first electrodes.

[0192] 3B shows light emitting device 130 as light emitting device 130R, light emitting device 130G, and light emitting device 130B. Light emitting device 130R, light emitting device 130G, and light emitting device 130B emit light of different colors. For example, light emitting device 130R can emit red light, light emitting device 130G can emit green light, and light emitting device 130B can emit blue light. Furthermore, light emitting device 130R, light emitting device 130G, or light emitting device 130B may emit other visible light or infrared light.

[0193] The organic compound layer 103 has at least a light-emitting layer and may have other functional layers (such as a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron injection layer). The organic compound layer 103 and the common layer 104 may be combined to form functional layers included in a light-emitting device (such as a hole injection layer, a hole transport layer, a hole blocking layer, a light-emitting layer, an electron blocking layer, an electron transport layer, and an electron injection layer).

[0194] The light-emitting device of one embodiment of the present invention can be, for example, a top-emission type that emits light in a direction opposite to a substrate on which the light-emitting device is formed. Note that the light-emitting device of one embodiment of the present invention may also be a bottom-emission type.

[0195] The light-emitting device 130R has the configuration shown in Embodiment 1 or 2. It has a first electrode (pixel electrode) composed of a conductive layer 151R and a conductive layer 152R, an organic compound layer 103R on the first electrode, a common layer 104 on the organic compound layer 103R, and a second electrode (common electrode) 102 on the common layer 104.

[0196] Note that the common layer 104 is not necessarily provided. By providing the common layer 104, damage to the organic compound layer 103R in a later process can be reduced. Furthermore, when the common layer 104 is provided, the common layer 104 may function as an electron injection layer. When the common layer 104 functions as an electron injection layer, the stacked structure of the organic compound layer 103R and the common layer 104 corresponds to the organic compound layer 103 in Embodiment 1.

[0197] Here, the light-emitting device 130 has the structure shown in Embodiment 1 or 2. It has a first electrode (pixel electrode) made of a conductive layer 151 and a conductive layer 152, an organic compound layer 103 on the first electrode, a common layer 104 on the organic compound layer 103, and a second electrode (common electrode) 102 on the common layer 104.

[0198] One of the pixel electrode and the common electrode of the light-emitting device functions as an anode and the other functions as a cathode. In the following description, unless otherwise specified, the pixel electrode functions as an anode and the common electrode functions as a cathode.

[0199] The organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B are independent island-shaped layers, each for each light-emitting color. By providing the organic compound layer 103 in an island shape for each light-emitting device 130, leakage current between adjacent light-emitting devices 130 can be suppressed even in a high-resolution light-emitting device. This prevents crosstalk and realizes a light-emitting device with extremely high contrast. In particular, a light-emitting device with high current efficiency at low luminance can be realized.

[0200] The organic compound layer 103 may be provided so as to cover the top and side surfaces of the first electrode (pixel electrode) of the light-emitting device 130. This makes it easier to increase the aperture ratio of the light-emitting device 1000 compared to a configuration in which the end of the organic compound layer 103 is located inside the end of the pixel electrode. Furthermore, covering the side surfaces of the pixel electrode of the light-emitting device 130 with the organic compound layer 103 prevents the pixel electrode from contacting the second electrode 102, thereby preventing short circuits in the light-emitting device 130. Furthermore, the distance between the light-emitting region of the organic compound layer 103 (i.e., the region overlapping with the pixel electrode) and the end of the organic compound layer 103 can be increased. Furthermore, since the end of the organic compound layer 103 may be damaged by processing, using a region away from the end of the organic compound layer 103 as the light-emitting region improves the reliability of the light-emitting device 130.

[0201] In the light-emitting device of one embodiment of the present invention, the first electrode (pixel electrode) of the light-emitting device may have a stacked-layer structure. For example, in the example shown in FIG. 3B , the first electrode of the light-emitting device 130 has a stacked-layer structure of a conductive layer 151 and a conductive layer 152.

[0202] For example, when the light-emitting device 1000 is a top-emission type, the pixel electrode of the light-emitting device 130 preferably has a conductive layer 151 with high reflectivity for visible light and a conductive layer 152 that is transparent to visible light and has a high work function. The higher the reflectivity of the pixel electrode for visible light, the higher the extraction efficiency of light emitted from the organic compound layer 103. Furthermore, when the pixel electrode functions as an anode, the higher the work function of the pixel electrode, the easier it is to inject holes into the organic compound layer 103. Therefore, by forming the pixel electrode of the light-emitting device 130 into a stacked structure of the conductive layer 151 with high reflectivity for visible light and the conductive layer 152 with a high work function, the light-emitting device 130 can be a light-emitting device with high light extraction efficiency and low driving voltage.

[0203] Specifically, the reflectance of the conductive layer 151 with respect to visible light is preferably, for example, 40% to 100%, and more preferably 70% to 100%. When the conductive layer 152 is used as an electrode that transmits visible light, the transmittance of the conductive layer 152 with respect to visible light is preferably, for example, 40% or more.

[0204] Furthermore, when a film formed after forming a pixel electrode having a laminated structure is removed by a wet etching method or the like, the structure may be impregnated with a chemical solution used for etching. If the impregnated chemical solution comes into contact with the pixel electrode, galvanic corrosion or the like may occur between the multiple layers that make up the pixel electrode, which may cause deterioration of the pixel electrode.

[0205] Therefore, it is preferable to form the conductive layer 152 so as to cover the top surface and side surfaces of the conductive layer 151. By covering the conductive layer 151 with the conductive layer 152, the impregnated chemical solution does not come into contact with the conductive layer 151, and galvanic corrosion of the pixel electrode can be suppressed. Therefore, the light-emitting device 1000 can be manufactured by a method with a high yield, and therefore can be a low-cost light-emitting device. Furthermore, since the occurrence of defects in the light-emitting device 1000 can be suppressed, the light-emitting device 1000 can be a highly reliable light-emitting device.

[0206] For example, a metal material can be used as the conductive layer 151. Specifically, metals such as 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, can also be used.

[0207] An oxide containing one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used for the conductive layer 152. For example, it is preferable to use a conductive oxide containing one or more of indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide containing gallium, titanium oxide, indium zinc oxide containing gallium, indium zinc oxide containing aluminum, indium tin oxide containing silicon, and indium zinc oxide containing silicon. In particular, indium tin oxide containing silicon has a large work function, for example, a work function of 4.0 eV or more, and therefore can be suitably used for the conductive layer 152.

[0208] The conductive layer 151 and the conductive layer 152 may have a stacked structure of multiple layers containing different materials. In this case, the conductive layer 151 may include a layer using a material that can be used for the conductive layer 152, such as a conductive oxide, or the conductive layer 152 may include a layer using a material that can be used for the conductive layer 151, such as a metal material. For example, when the conductive layer 151 has a stacked structure of two or more layers, the layer in contact with the conductive layer 152 can be a layer containing the same material as the layer of the conductive layer 152 in contact with the conductive layer 151.

[0209] Note that the conductive layer 151 preferably has a tapered edge. Specifically, the conductive layer 151 preferably has a tapered edge with a taper angle of less than 90°. In this case, the conductive layer 152 provided along the side surface of the conductive layer 151 also has a tapered edge. By tapering the edge of the conductive layer 152, coverage of the organic compound layer 103 provided along the side surface of the conductive layer 152 can be improved.

[0210] In the case where the conductive layer 151 or the conductive layer 152 has a layered structure, at least one side surface thereof preferably has a tapered shape. In addition, in the layered structure constituting each conductive layer, each layer may have a different tapered shape.

[0211] 4A illustrates a case where the conductive layer 151 has a stacked structure of multiple layers containing different materials. As shown in FIG. 4A, the conductive layer 151 has a structure including a conductive layer 151_1, a conductive layer 151_2 on the conductive layer 151_1, and a conductive layer 151_3 on the conductive layer 151_2. That is, the conductive layer 151 shown in FIG. 4A has a three-layer stacked structure. In this way, when the conductive layer 151 has a stacked structure of multiple layers, the reflectivity of at least one layer constituting the conductive layer 151 to visible light is made higher than the reflectivity of the conductive layer 152 to visible light.

[0212] 4A , the conductive layer 151_2 is sandwiched between the conductive layer 151_1 and the conductive layer 151_3. The conductive layer 151_1 and the conductive layer 151_3 are preferably made of a material that is less likely to change in quality than the conductive layer 151_2. For example, the conductive layer 151_1 can be made of a material that is less likely to migrate due to contact with the insulating layer 175 than the conductive layer 151_2. The conductive layer 151_3 can be made of a material that is less likely to oxidize than the conductive layer 151_2 and has an oxide with lower electrical resistivity than the oxide of the material used for the conductive layer 151_2.

[0213] As described above, by sandwiching the conductive layer 151_2 between the conductive layer 151_1 and the conductive layer 151_3, the range of material options for the conductive layer 151_2 can be expanded. This allows the conductive layer 151_2 to have a higher reflectivity for visible light than at least one of the conductive layer 151_1 and the conductive layer 151_3. For example, aluminum can be used for the conductive layer 151_2. Note that an alloy containing aluminum may be used for the conductive layer 151_2. Furthermore, titanium, which has a lower reflectivity for visible light than aluminum but is less likely to migrate than aluminum even when in contact with the insulating layer 175, can be used for the conductive layer 151_1. Furthermore, titanium, which has a lower reflectivity for visible light than aluminum but is less likely to oxidize than aluminum and has an oxide with lower electrical resistivity than aluminum oxide, can be used for the conductive layer 151_3.

[0214] Alternatively, silver or an alloy containing silver may be used for the conductive layer 151_3. Silver has a higher reflectivity to visible light than titanium. Furthermore, silver is less susceptible to oxidation than aluminum, and the electrical resistivity of silver oxide is lower than that of aluminum oxide. As described above, using silver or an alloy containing silver for the conductive layer 151_3 can favorably increase the reflectivity of the conductive layer 151 to visible light while suppressing an increase in the electrical resistance of the pixel electrode due to oxidation of the conductive layer 151_2. Here, an alloy containing silver may be, for example, an alloy of silver, palladium, and copper (Ag-Pd-Cu, also referred to as APC). Note that using silver or an alloy containing silver for the conductive layer 151_3 and aluminum for the conductive layer 151_2 can increase the reflectivity of the conductive layer 151_3 to visible light compared to the reflectivity of the conductive layer 151_2 to visible light. Here, silver or an alloy containing silver may be used for the conductive layer 151_2. Alternatively, the conductive layer 151_1 may be formed using silver or an alloy containing silver.

[0215] On the other hand, a film using titanium has better etching processability than a film using silver. Therefore, by using titanium for the conductive layer 151_3, the conductive layer 151_3 can be easily formed. Note that a film using aluminum also has better etching processability than a film using silver.

[0216] As described above, the characteristics of the light-emitting device can be improved by forming the conductive layer 151 into a stacked structure of a plurality of layers. For example, the light-emitting device 1000 can be a light-emitting device with high light extraction efficiency and high reliability.

[0217] Here, when a microcavity structure is applied to the light-emitting device 130, the light extraction efficiency of the light-emitting device 1000 can be suitably improved by using silver, which is a material with high reflectivity for visible light, or an alloy containing silver as the conductive layer 151_3.

[0218] 4A , depending on the material selection or processing method of the conductive layer 151, the side surface of the conductive layer 151_2 may be located inside the side surfaces of the conductive layer 151_1 and the conductive layer 151_3, forming a protruding portion, which may reduce the coverage of the conductive layer 152 with respect to the conductive layer 151, and may cause a step disconnection of the conductive layer 152.

[0219] Therefore, it is preferable to provide the insulating layer 156 as shown in Fig. 4A. Fig. 4A shows an example in which the insulating layer 156 is provided over the conductive layer 151_1 so as to have a region overlapping with the side surface of the conductive layer 151_2. This can prevent the conductive layer 152 from being broken or thinned due to the protrusion, thereby suppressing poor connection or an increase in driving voltage.

[0220] 4A illustrates a structure in which the side surfaces of the conductive layer 151_2 are entirely covered with the insulating layer 156, but the side surfaces of the conductive layer 151_2 may not be partially covered with the insulating layer 156. Similarly, in pixel electrodes having structures described below, the side surfaces of the conductive layer 151_2 may not be partially covered with the insulating layer 156.

[0221] 4A, the insulating layer 156 preferably has a curved surface. This can reduce the occurrence of discontinuities in the conductive layer 152 covering the insulating layer 156, compared to when the side surfaces of the insulating layer 156 are vertical (parallel to the Z direction). Even when the insulating layer 156 has a tapered side surface, specifically a tapered shape with a taper angle of less than 90°, the occurrence of discontinuities in the conductive layer 152 covering the insulating layer 156 can be reduced, compared to when the side surfaces of the insulating layer 156 are vertical. As described above, the light-emitting device 1000 can be manufactured using a method with a high yield. Furthermore, the occurrence of defects can be reduced, making the light-emitting device 1000 a highly reliable light-emitting device.

[0222] Note that one embodiment of the present invention is not limited thereto. For example, other structures of the first electrode 101 are shown in FIGS.

[0223] FIG. 4B shows a structure in which the insulating layer 156 covers not only the side surfaces of the conductive layer 151_2 but also the side surfaces of the conductive layer 151_1, the conductive layer 151_2, and the conductive layer 151_3 in the first electrode 101 of FIG. 4A.

[0224] FIG. 4C shows a configuration in which the insulating layer 156 is not provided in the first electrode 101 of FIG. 4A.

[0225] FIG. 4D shows a structure in which the conductive layer 151 does not have a layered structure and the conductive layer 152 has a layered structure in the first electrode 101 of FIG. 4A.

[0226] The conductive layer 152_1 has higher adhesion to the conductive layer 152_2 than the insulating layer 175, for example. The conductive layer 152_1 can be formed using an oxide containing one or more of indium, tin, zinc, gallium, titanium, aluminum, and silicon. For example, a conductive oxide containing one or more of indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide containing gallium, titanium oxide, indium titanium oxide, zinc titanate, aluminum zinc oxide, indium zinc oxide containing gallium, indium zinc oxide containing aluminum, indium tin oxide containing silicon, and indium zinc oxide containing silicon can be preferably used. This can prevent peeling of the conductive layer 152_2. Furthermore, the conductive layer 152_2 can be configured not to be in contact with the insulating layer 175.

[0227] The conductive layer 152_2 has a higher reflectivity for visible light than the conductive layer 151, the conductive layer 152_1, and the conductive layer 152_3. The reflectivity for visible light of the conductive layer 152_2 can be, for example, 70% to 100%, preferably 80% to 100%, and more preferably 90% to 100%. The conductive layer 152_2 can be made of, for example, silver or an alloy containing silver. An example of an alloy containing silver is an alloy of silver, palladium, and copper (APC). As described above, the light-emitting device 1000 can have high light extraction efficiency. Note that a metal other than silver may be used for the conductive layer 152_2.

[0228] When the conductive layers 151 and 152 function as anodes, the conductive layer 152_3 preferably has a high work function. The conductive layer 152_3 has a work function higher than that of the conductive layer 152_2, for example. The conductive layer 152_3 can be made of the same material as that of the conductive layer 152_1, for example. For example, the conductive layer 152_1 and the conductive layer 152_3 can be made of the same material.

[0229] Note that when the conductive layers 151 and 152 function as cathodes, the conductive layer 152_3 preferably has a low work function, for example, a work function smaller than that of the conductive layer 152_2.

[0230] The conductive layer 152_3 is preferably a layer having high transmittance to visible light. For example, the transmittance of the conductive layer 152_3 to visible light is preferably higher than that of the conductive layer 151 and the conductive layer 152_2 to visible light. For example, the transmittance of the conductive layer 152_3 to visible light can be 40% to 100%, preferably 60% to 100%. As a result, the amount of light emitted from the organic compound layer 103 that is absorbed by the conductive layer 152_3 can be reduced. As described above, the conductive layer 152_2 under the conductive layer 152_3 can be a layer having high reflectance to visible light. Therefore, the light-emitting device 1000 can have high light extraction efficiency.

[0231] Next, an example of a method for manufacturing the light emitting device 1000 having the structure shown in FIG. 3 will be described with reference to FIGS.

[0232] [Example of Manufacturing Method] Thin films (insulating films, semiconductor films, conductive films, etc.) constituting the light-emitting device can be formed using a sputtering method, a chemical vapor deposition (CVD) method, a vacuum evaporation method, a pulsed laser deposition (PLD) method, an ALD method, etc. CVD methods include a plasma enhanced chemical vapor deposition (PECVD) method and a thermal CVD method. One type of thermal CVD method is a metal organic chemical vapor deposition (MOCVD) method.

[0233] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) constituting the light-emitting device can be formed by a wet film-forming method such as spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, or knife coating.

[0234] In particular, vacuum processes such as vapor deposition, and solution processes such as spin coating and inkjet printing can be used to fabricate light-emitting devices. Vapor deposition methods include physical vapor deposition (PVD) methods such as sputtering, ion plating, ion beam deposition, molecular beam deposition, and vacuum deposition, and chemical vapor deposition (CVD). In particular, functional layers (hole injection layer, hole transport layer, hole blocking layer, light-emitting layer, electron blocking layer, electron transport layer, electron injection layer, etc.) included in the organic compound layer can be formed by vapor deposition (vacuum deposition, etc.), coating methods (dip coating, die coating, bar coating, spin coating, spray coating, etc.), printing methods (inkjet printing, screen (stencil printing), offset (lithographic printing), flexography (relief printing), gravure, microcontact printing, etc.), etc.

[0235] Furthermore, when processing the thin film that constitutes the light-emitting device, it can be processed using, for example, a photolithography method. Alternatively, the thin film may be processed using a nanoimprint method, a sandblasting method, a lift-off method, etc. Furthermore, the island-shaped thin film may be directly formed by a film formation method using a shielding mask such as a metal mask.

[0236] There are two typical photolithography methods: one is to form a resist mask on the thin film to be processed, process the thin film by etching, and then remove the resist mask; the other is to form a photosensitive thin film, and then process the thin film into the desired shape by exposure and development.

[0237] The thin film can be etched by dry etching, wet etching, sandblasting, or the like.

[0238] 5A, an insulating layer 171 is formed on a substrate (not shown). Subsequently, conductive layers 172 and 179 are formed on the insulating layer 171, and an insulating layer 173 is formed on the insulating layer 171 so as to cover the conductive layers 172 and 179. Subsequently, an insulating layer 174 is formed on the insulating layer 173, and an insulating layer 175 is formed on the insulating layer 174.

[0239] The substrate may be a substrate having heat resistance sufficient to withstand at least a subsequent heat treatment. When an insulating substrate is used, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, an organic resin substrate, or the like may be used. Furthermore, a semiconductor substrate such as a single-crystal semiconductor substrate made of silicon or silicon carbide, a polycrystalline semiconductor substrate, a compound semiconductor substrate such as silicon germanium, or an SOI substrate may be used.

[0240] 5A, openings are formed in the insulating layers 175, 174, and 173, reaching the conductive layer 172. Then, plugs 176 are formed to fill the openings.

[0241] 5A , a conductive film 151f, which will later become the conductive layers 151R, 151G, 151B, and 151C, is formed on the plug 176 and the insulating layer 175. The conductive film 151f can be formed by, for example, sputtering or vacuum deposition. The conductive film 151f can be made of, for example, a metal material.

[0242] 5A, a resist mask 191 is formed over the conductive film 151f, for example. The resist mask 191 can be formed by applying a photosensitive material (photoresist) and then performing exposure and development.

[0243] 5B , for example, the conductive film 151f in a region that does not overlap with the resist mask 191 is removed by, for example, etching, specifically, dry etching. Note that if the conductive film 151f includes a layer using a conductive oxide such as indium tin oxide, the layer may be removed by wet etching. As a result, the conductive layer 151 is formed. Note that, for example, when part of the conductive film 151f is removed by dry etching, a recess (also referred to as a countersink) may be formed in a region of the insulating layer 175 that does not overlap with the conductive layer 151.

[0244] 5C, the resist mask 191 is removed. The resist mask 191 can be removed by ashing using oxygen plasma, or by ashing using oxygen gas and CF ４ , C ４ F ８ , S.F. ６ , CHF ３ , Cl ２ , H ２ O, BCl ３ Alternatively, a Group 18 element such as He may be used. Alternatively, the resist mask 191 may be removed by wet etching.

[0245] 5D , an insulating film 156f, which will later become the insulating layer 156R, the insulating layer 156G, the insulating layer 156B, and the insulating layer 156C, is formed on the conductive layer 151R, the conductive layer 151G, the conductive layer 151B, the conductive layer 151C, and the insulating layer 175. The insulating film 156f can be formed by, for example, a CVD method, an ALD method, a sputtering method, or a vacuum deposition method.

[0246] The insulating film 156f can be formed using an inorganic material. For example, the insulating film 156f can be formed using an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film. For example, the insulating film 156f can be formed using an oxide insulating film containing silicon, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film. For example, the insulating film 156f can be formed using silicon oxynitride.

[0247] 5E, the insulating film 156f is processed to form insulating layers 156R, 156G, 156B, and 156C. For example, the insulating layer 156 can be formed by uniformly etching the top surface of the insulating film 156f. Such uniform etching and planarization is also called an etch-back process. The insulating layer 156 may also be formed by photolithography.

[0248] 6A , a conductive film 152f, which will later become the conductive layers 152R, 152G, 152B, and 152C, is formed on the conductive layers 151R, 151G, 151B, 151C, the insulating layers 156R, 156G, 156B, 156C, and the insulating layer 175. Specifically, the conductive film 152f is formed so as to cover, for example, the conductive layers 151R, 151G, 151B, 151C, the insulating layers 156R, 156G, 156B, and 156C.

[0249] The conductive film 152f can be formed by, for example, sputtering or vacuum evaporation. Alternatively, the conductive film 152f can be formed by ALD. Alternatively, the conductive film 152f can be formed using, for example, a conductive oxide. Alternatively, the conductive film 152f can have a stacked structure of a film using a metal material and a film using a conductive oxide thereon. For example, the conductive film 152f can have a stacked structure of a film using titanium, silver, or an alloy containing silver and a film using a conductive oxide thereon.

[0250] 6B , the conductive film 152f is processed by, for example, photolithography to form conductive layers 152R, 152G, 152B, and 152C. Specifically, for example, after forming a resist mask, part of the conductive film 152f is removed by etching. The conductive film 152f can be removed by, for example, wet etching. Alternatively, the conductive film 152f may be removed by dry etching. In this manner, a pixel electrode including the conductive layer 151 and the conductive layer 152 is formed.

[0251] Subsequently, it is preferable to perform hydrophobic treatment on the conductive layer 152. The hydrophobic treatment can change the surface to be treated from hydrophilic to hydrophobic, or can increase the hydrophobicity of the surface to be treated. By performing the hydrophobic treatment on the conductive layer 152, adhesion between the conductive layer 152 and the organic compound layer 103 formed in a later step can be increased, and film peeling can be suppressed. Note that the hydrophobic treatment is not necessarily performed.

[0252] Subsequently, as shown in FIG. 6C, an organic compound film 103Bf, which will later become the organic compound layer 103B, is formed on the conductive layers 152B, 152G, 152R, and the insulating layer 175.

[0253] In the present invention, the organic compound film 103Bf has a plurality of organic compound layers each having at least one light-emitting layer. Specifically, the structure of the light-emitting device described in Embodiment 2 can be referred to. Alternatively, the organic compound film 103Bf may have a structure in which a plurality of organic compound layers each having at least one light-emitting layer are stacked with an intermediate layer interposed therebetween.

[0254] 6C , the organic compound film 103Bf is not formed on the conductive layer 152C. For example, by using a mask for defining the film formation area (also called an area mask or a rough metal mask, to distinguish it from a fine metal mask), the organic compound film 103Bf can be formed only in the desired region. By employing a film formation process using an area mask and a processing process using a resist mask, the light-emitting device can be manufactured through a relatively simple process.

[0255] The organic compound film 103Bf can be formed by, for example, a vapor deposition method, specifically a vacuum deposition method. Alternatively, the organic compound film 103Bf may be formed by a transfer method, a printing method, an inkjet method, a coating method, or the like.

[0256] Subsequently, as shown in FIG. 6D, a sacrificial film 158Bf, which will later become the sacrificial layer 158B, and a mask film 159Bf, which will later become the mask layer 159B, are formed in this order on the organic compound film 103Bf.

[0257] The sacrificial film 158Bf and the mask film 159Bf can be formed by, for example, sputtering, ALD (thermal ALD, PEALD), CVD, or vacuum deposition. Alternatively, they may be formed by the wet film formation method described above.

[0258] The sacrificial film 158Bf and the mask film 159Bf are formed at a temperature lower than the heat-resistant temperature of the organic compound film 103Bf. The substrate temperature when forming the sacrificial film 158Bf and the mask film 159Bf is typically 200° C. or lower, preferably 150° C. or lower, more preferably 120° C. or lower, more preferably 100° C. or lower, and even more preferably 80° C. or lower.

[0259] In this embodiment, an example is shown in which the mask film is formed with a two-layer structure of the sacrificial film 158Bf and the mask film 159Bf, but the mask film may have a single-layer structure or a laminated structure of three or more layers.

[0260] By providing a sacrificial film on the organic compound film 103Bf, damage to the organic compound film 103Bf during the manufacturing process of the light-emitting device can be reduced, and the reliability of the light-emitting device can be improved.

[0261] The sacrificial film 158Bf is made of a film that is highly resistant to the processing conditions of the organic compound film 103Bf, specifically, a film that has a high etching selectivity with respect to the organic compound film 103Bf, and the mask film 159Bf is made of a film that has a high etching selectivity with respect to the sacrificial film 158Bf.

[0262] The sacrificial film 158Bf and the mask film 159Bf are preferably made of films that can be removed by wet etching, which can reduce damage to the organic compound film 103Bf during processing of the sacrificial film 158Bf and the mask film 159Bf compared to when dry etching is used.

[0263] When wet etching is used, it is particularly preferable to use an acidic chemical solution, such as a chemical solution containing any one of phosphoric acid, hydrofluoric acid, nitric acid, acetic acid, oxalic acid, and sulfuric acid, or a mixed chemical solution of two or more acids (also called mixed acid).

[0264] The sacrificial film 158Bf and the mask film 159Bf may each be made of one or more of a metal film, an alloy film, a metal oxide film, a semiconductor film, an organic insulating film, an inorganic insulating film, or the like.

[0265] Furthermore, by using a film containing a material that blocks ultraviolet light for the sacrificial film 158Bf and the mask film 159Bf, it is possible to prevent the organic compound layer from being irradiated with ultraviolet light during, for example, an exposure process. Suppressing damage to the organic compound layer due to ultraviolet light can improve the reliability of the light-emitting device.

[0266] The same effect can be achieved when a film containing a material that blocks ultraviolet light is used as the material for the inorganic insulating film 125f, which will be described later.

[0267] The sacrificial film 158Bf and the mask film 159Bf 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.

[0268] Furthermore, for the sacrificial film 158Bf and the mask film 159Bf, metal oxides such as In—Ga—Zn oxide, indium oxide, In—Zn 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), indium gallium tin zinc oxide (In—Ga—Sn—Zn oxide), and indium tin oxide containing silicon can be used, respectively.

[0269] In addition, instead of the above gallium, an element M (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) may be used.

[0270] Furthermore, using semiconductor materials such as silicon or germanium for the sacrificial film 158Bf and the mask film 159Bf is preferable because they have high compatibility with semiconductor manufacturing processes. Oxides or nitrides of the above semiconductor materials can also be used. Non-metallic materials such as carbon or their compounds can also be used. Metals such as titanium, tantalum, tungsten, chromium, and aluminum, or alloys containing one or more of these metals can also be used. Oxides containing the above metals, such as titanium oxide or chromium oxide, or nitrides such as titanium nitride, chromium nitride, or tantalum nitride can also be used.

[0271] Furthermore, various inorganic insulating films can be used for the sacrificial film 158Bf and the mask film 159Bf. In particular, oxide insulating films are preferable because they have higher adhesion to the organic compound film 103Bf than nitride insulating films. For example, inorganic insulating materials such as aluminum oxide, hafnium oxide, and silicon oxide can be used for the sacrificial film 158Bf and the mask film 159Bf. For example, aluminum oxide films can be formed as the sacrificial film 158Bf and the mask film 159Bf using the ALD method. Using the ALD method is preferable because it reduces damage to the underlying layer (particularly the organic compound layer).

[0272] Alternatively, an organic material may be used for one or both of the sacrificial film 158Bf and the mask film 159Bf. For example, a material that can be dissolved in a chemically stable solvent may be used as the organic material, at least for the film located at the top of the organic compound film 103Bf. Materials that dissolve in water or alcohol are particularly suitable. When forming a film of such a material, it is preferable to apply the material 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. Performing the heat treatment under a reduced pressure atmosphere allows the solvent to be removed at a low temperature in a short time, thereby reducing thermal damage to the organic compound film 103Bf, which is preferable.

[0273] The sacrificial film 158Bf and the mask film 159Bf may each be made of an organic resin such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, alcohol-soluble polyamide resin, or a fluororesin such as a perfluoropolymer.

[0274] For example, the sacrificial film 158Bf may be an organic film (e.g., a PVA film) formed using either a vapor deposition method or the above-mentioned wet film formation method, and the mask film 159Bf may be an inorganic film (e.g., a silicon nitride film) formed using a sputtering method.

[0275] 6D, a resist mask 190B is formed on the mask film 159Bf. The resist mask 190B can be formed by applying a photosensitive material (photoresist) and then performing exposure and development.

[0276] The resist mask 190B may be made of either a positive resist material or a negative resist material.

[0277] The resist mask 190B is provided in a position overlapping with the conductive layer 152B. The resist mask 190B is preferably also provided in a position overlapping with the conductive layer 152C. This can prevent the conductive layer 152C from being damaged during the manufacturing process of the light-emitting device. Note that the resist mask 190B does not necessarily have to be provided on the conductive layer 152C. Furthermore, as shown in the cross-sectional view between B1 and B2 in FIG. 6C , the resist mask 190B is preferably provided so as to cover from the end of the organic compound film 103Bf to the end of the conductive layer 152C (the end on the organic compound film 103Bf side).

[0278] 6E, a resist mask 190B is used to remove a portion of the mask film 159Bf to form a mask layer 159B. The mask layer 159B remains on the conductive layer 152B and the conductive layer 152C. The resist mask 190B is then removed. The mask layer 159B is used as a mask (also referred to as a hard mask) to remove a portion of the sacrificial film 158Bf to form a sacrificial layer 158B.

[0279] The sacrificial film 158Bf and the mask film 159Bf can be processed by wet etching or dry etching, respectively, and are preferably processed by wet etching.

[0280] The wet etching method can reduce damage to the organic compound film 103Bf when processing the sacrificial film 158Bf and the mask film 159Bf compared to the dry etching method. When the wet etching method is used, it is preferable to use a chemical solution such as a developer, a tetramethylammonium hydroxide solution (TMAH), diluted hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof.

[0281] In processing the mask film 159Bf, the organic compound film 103Bf is not exposed, and therefore the range of processing methods to be selected is wider than in processing the sacrificial film 158Bf. Specifically, even when a gas containing oxygen is used as an etching gas in processing the mask film 159Bf, deterioration of the organic compound film 103Bf can be further suppressed.

[0282] When wet etching is used, it is particularly preferable to use an acidic chemical solution, such as a chemical solution containing any one of phosphoric acid, hydrofluoric acid, nitric acid, acetic acid, oxalic acid, and sulfuric acid, or a mixed chemical solution of two or more acids (also called mixed acid).

[0283] Furthermore, when dry etching is used to process the sacrificial film 158Bf, deterioration of the organic compound film 103Bf can be suppressed by not using a gas containing oxygen as the etching gas. ４ , C ４ F ８ , S.F. ６ , CHF ３ , Cl ２ , H ２ O, BCl ３ It is preferable to use a gas containing a Group 18 element such as He or the like as the etching gas.

[0284] The resist mask 190B can be removed by the same method as the resist mask 191. At this time, the sacrificial film 158Bf is located on the outermost surface and the organic compound film 103Bf is not exposed, so that damage to the organic compound film 103Bf can be suppressed in the process of removing the resist mask 190B. Furthermore, the range of options for removing the resist mask 190B can be expanded.

[0285] 6E, the organic compound film 103Bf is processed to form the organic compound layer 103B. For example, the mask layer 159B and the sacrificial layer 158B are used as a hard mask to remove a portion of the organic compound film 103Bf, thereby forming the organic compound layer 103B.

[0286] 6E, a stacked structure of the organic compound layer 103B, the sacrificial layer 158B, and the mask layer 159B remains on the conductive layer 152B, and the conductive layers 152G and 152R are exposed.

[0287] The organic compound film 103Bf can be processed by dry etching or wet etching. For example, when processing by dry etching, an etching gas containing oxygen can be used. When the etching gas contains oxygen, the etching rate can be increased. Therefore, etching can be performed under low power conditions while maintaining a sufficiently high etching rate. This makes it possible to suppress damage to the organic compound film 103Bf. Furthermore, it is possible to suppress problems such as adhesion of reaction products that occur during etching.

[0288] Alternatively, an etching gas that does not contain oxygen may be used, for example, by using an etching gas that does not contain oxygen, deterioration of the organic compound film 103Bf can be suppressed.

[0289] As described above, in one embodiment of the present invention, the resist mask 190B is formed over the mask film 159Bf, and part of the mask film 159Bf is removed using the resist mask 190B to form the mask layer 159B. Then, part of the organic compound film 103Bf is removed using the mask layer 159B as a hard mask to form the organic compound layer 103B. Therefore, it can be said that the organic compound layer 103B is formed by processing the organic compound film 103Bf using photolithography. Note that part of the organic compound film 103Bf may be removed using the resist mask 190B. Then, the resist mask 190B may be removed.

[0290] Here, the conductive layer 152G may be subjected to hydrophobic treatment as needed. During processing of the organic compound film 103Bf, for example, the surface state of the conductive layer 152G may change to a hydrophilic state. For example, by subjecting the conductive layer 152G to hydrophobic treatment, for example, the adhesion between the conductive layer 152G and a layer (here, the organic compound layer 103G) formed in a later process can be improved, and film peeling can be suppressed.

[0291] Subsequently, as shown in FIG. 7A, an organic compound film 103Gf, which will later become the organic compound layer 103G, is formed on the conductive layer 152G, the conductive layer 152R, the mask layer 159B, and the insulating layer 175.

[0292] The organic compound film 103Gf can be formed by the same method as that used to form the organic compound film 103Bf, and can have the same structure as the organic compound film 103Bf.

[0293] 7B , a sacrificial film 158Gf, which will later become the sacrificial layer 158G, and a mask film 159Gf, which will later become the mask layer 159G, are sequentially formed on the organic compound film 103Gf and the mask layer 159B. A resist mask 190G is then formed. The materials and formation methods for the sacrificial film 158Gf and the mask film 159Gf are the same as those applicable to the sacrificial film 158Bf and the mask film 159Bf. The materials and formation methods for the resist mask 190G are the same as those applicable to the resist mask 190B.

[0294] The resist mask 190G is provided in a position overlapping with the conductive layer 152G.

[0295] 7C , a resist mask 190G is used to remove a portion of the mask film 159Gf to form a mask layer 159G. The mask layer 159G remains on the conductive layer 152G. The resist mask 190G is then removed. The mask layer 159G is then used as a mask to remove a portion of the sacrificial film 158Gf to form a sacrificial layer 158G. The organic compound film 103Gf is then processed to form the organic compound layer 103G. For example, the mask layer 159G and the sacrificial layer 158G are used as hard masks to remove a portion of the organic compound film 103Gf to form the organic compound layer 103G.

[0296] 7C, a laminated structure of the organic compound layer 103G, the sacrificial layer 158G, and the mask layer 159G remains on the conductive layer 152G, and the mask layer 159B and the conductive layer 152R are exposed.

[0297] In addition, for example, the conductive layer 152R may be subjected to a hydrophobic treatment.

[0298] Subsequently, as shown in FIG. 8A, an organic compound film 103Rf, which will later become the organic compound layer 103R, is formed on the conductive layer 152R, the mask layer 159G, the mask layer 159B, and the insulating layer 175.

[0299] The organic compound film 103Rf can be formed by the same method as that used to form the organic compound film 103Gf, and can have the same structure as the organic compound film 103Gf.

[0300] 8B and 8C , a resist mask 190R is used to form a sacrificial layer 158R from the sacrificial film 158Rf, a mask layer 159R from the mask film 159Rf, or an organic compound layer 103R from the organic compound film 103Rf. The methods for forming the sacrificial layer 158R, the mask layer 159R, and the organic compound layer 103R can be seen in the description of the organic compound layer 103G.

[0301] It is preferable that the side surfaces of the organic compound layers 103B, 103G, and 103R are perpendicular or substantially perpendicular to the surface on which they are formed. For example, it is preferable that the angle formed between the surface on which they are formed and these side surfaces be 60 degrees or more and 90 degrees or less.

[0302] As described above, the distance between adjacent pairs of the organic compound layers 103B, 103G, and 103R formed using photolithography can be narrowed to 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. Here, the distance can be defined, for example, as the distance between the opposing ends of adjacent pairs of the organic compound layers 103B, 103G, and 103R. By narrowing the distance between the island-shaped organic compound layers in this manner, a light-emitting device with high definition and a large aperture ratio can be provided. Furthermore, the distance between the first electrodes of adjacent light-emitting devices can also be narrowed, for example, to 10 μm or less, 8 μm or less, 5 μm or less, 3 μm or less, or 2 μm or less. Note that the distance between the first electrodes of adjacent light-emitting devices is preferably 2 μm or more and 5 μm or less.

[0303] Next, as shown in FIG. 9A, the mask layers 159B, 159G, and 159R are removed.

[0304] Although the present embodiment will be described taking as an example a case where the mask layers 159B, 159G, and 159R are removed, it is not necessary to remove the mask layers 159B, 159G, and 159R. For example, if the mask layers 159B, 159G, and 159R contain the aforementioned material that has a light-blocking property against ultraviolet light, the organic compound layer can be protected from light irradiation (including illumination light) by proceeding to the next step without removing them.

[0305] The mask layer removal process can be performed using the same method as the mask film processing process. In particular, by using a wet etching method, damage to the organic compound layers 103B, 103G, and 103R during the mask layer removal process can be reduced compared to when a dry etching method is used.

[0306] The mask layer may also be removed by dissolving it in a solvent such as water or alcohol, such as ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin.

[0307] After removing the mask layer, a drying treatment may be performed to remove water contained in the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R, as well as water adsorbed on the surfaces of the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R. For example, a heat treatment can be performed in an inert atmosphere or a reduced-pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50° C. or higher and 200° C. or lower, preferably 60° C. or higher and 150° C. or lower, and more preferably 70° C. or higher and 120° C. or lower. A reduced-pressure atmosphere is preferable because it enables drying at a lower temperature.

[0308] Next, as shown in FIG. 9B, an inorganic insulating film 125f, which will later become the inorganic insulating layer 125, is formed to cover the organic compound layer 103B, the organic compound layer 103G, the organic compound layer 103R, the sacrificial layer 158B, the sacrificial layer 158G, and the sacrificial layer 158R.

[0309] As will be described later, an insulating film that will later become the insulating layer 127 is formed in contact with the upper surface of the inorganic insulating film 125f. Therefore, it is preferable that the upper surface of the inorganic insulating film 125f has a high affinity with the material (e.g., a photosensitive resin composition containing an acrylic resin) used for the insulating film that will become the insulating layer 127. To improve this affinity, a surface treatment may be performed on the upper surface of the inorganic insulating film 125f. Specifically, it is preferable to hydrophobize (or increase the hydrophobicity of) the surface of the inorganic insulating film 125f. For example, it is preferable to perform the treatment using a silylating agent such as hexamethyldisilazane (HMDS). By hydrophobizing the upper surface of the inorganic insulating film 125f in this manner, the insulating film 127f can be formed with good adhesion.

[0310] Subsequently, as shown in FIG. 9C, an insulating film 127f, which will later become the insulating layer 127, is formed on the inorganic insulating film 125f.

[0311] The inorganic insulating film 125f and the insulating film 127f are preferably formed by a formation method that causes less damage to the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R. In particular, since the inorganic insulating film 125f is formed in contact with the side surfaces of the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R, it is preferably formed by a formation method that causes less damage to the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R than the insulating film 127f.

[0312] The inorganic insulating film 125f and the insulating film 127f are formed at a temperature lower than the heat-resistant temperatures of the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R, respectively. By increasing the substrate temperature during film formation, the inorganic insulating film 125f can be formed as a film with a low impurity concentration and a high barrier property against at least one of water and oxygen, even if it is thin.

[0313] The substrate temperature when forming the inorganic insulating film 125f and the insulating film 127f is preferably 60°C or higher, 80°C or higher, 100°C or higher, or 120°C or higher, and 200°C or lower, 180°C or lower, 160°C or lower, 150°C or lower, or 140°C or lower, respectively.

[0314] As the inorganic insulating film 125f, it is preferable to form an insulating film having a thickness of 3 nm or more, 5 nm or more, or 10 nm or more, and 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less within the above substrate temperature range.

[0315] The inorganic insulating film 125f is preferably formed by, for example, the ALD method. The ALD method is preferable because it can reduce film formation damage and form a film with high coverage. The inorganic insulating film 125f is preferably formed as an aluminum oxide film by, for example, the ALD method.

[0316] Alternatively, the inorganic insulating film 125f may be formed by sputtering, CVD, or PECVD, which have a faster film formation rate than ALD, thereby enabling highly reliable light-emitting devices to be manufactured with high productivity.

[0317] The insulating film 127f is preferably formed by the wet film formation method described above. The insulating film 127f is preferably formed by, for example, spin coating using a photosensitive material, more specifically, using a photosensitive resin composition containing an acrylic resin.

[0318] The insulating film 127f is preferably formed using, for example, a resin composition containing a polymer, an acid generator, and a solvent. The polymer is formed using one or more types of monomers and has a structure in which one or more types of structural units (also referred to as constituent units) are regularly or irregularly repeated. As the acid generator, one or both of a compound that generates an acid upon irradiation with light and a compound that generates an acid upon heating can be used. The resin composition may further contain one or more of a photosensitizer, a sensitizer, a catalyst, an adhesion aid, a surfactant, and an antioxidant.

[0319] Furthermore, heat treatment (also referred to as pre-baking) is preferably performed after the insulating film 127f is formed. The heat treatment is performed at a temperature lower than the heat resistance temperature of the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R. The substrate temperature during the heat treatment is preferably 50° C. or higher and 200° C. or lower, more preferably 60° C. or higher and 150° C. or lower, and even more preferably 70° C. or higher and 120° C. or lower. This allows the solvent contained in the insulating film 127f to be removed.

[0320] Next, exposure is performed to expose a portion of the insulating film 127f to visible light or ultraviolet light. If a positive-type photosensitive resin composition containing an acrylic resin is used for the insulating film 127f, visible light or ultraviolet light is irradiated onto the region where the insulating layer 127 will not be formed in a later process. The insulating layer 127 is formed in the region sandwiched between any two of the conductive layers 152B, 152G, and 152R, and around the conductive layer 152C. Therefore, visible light or ultraviolet light is irradiated onto the conductive layers 152B, 152G, 152R, and 152C. If a negative-type photosensitive material is used for the insulating film 127f, visible light or ultraviolet light is irradiated onto the region where the insulating layer 127 will be formed.

[0321] The width of the insulating layer 127 to be formed later can be controlled by the exposed region of the insulating film 127f. In this embodiment mode, the insulating layer 127 is processed to have a portion overlapping with the top surface of the conductive layer 151.

[0322] Here, by providing a barrier insulating layer against oxygen (e.g., an aluminum oxide film) as one or both of the sacrificial layer 158 (sacrificial layer 158B, sacrificial layer 158G, and sacrificial layer 158R) and the inorganic insulating film 125f, it is possible to reduce the diffusion of oxygen into the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R. When the organic compound layer is irradiated with light (visible light or ultraviolet light), the organic compound contained in the organic compound layer becomes excited, which may promote a reaction with oxygen contained in the atmosphere. More specifically, when the organic compound layer is irradiated with light (visible light or ultraviolet light) in an oxygen-containing atmosphere, oxygen may bond to the organic compound contained in the organic compound layer. By providing the sacrificial layer 158 and the inorganic insulating film 125f on the island-shaped organic compound layer, it is possible to reduce the bonding of oxygen in the atmosphere to the organic compound contained in the organic compound layer.

[0323] 10A, development is performed to remove the exposed regions of the insulating film 127f, thereby forming an insulating layer 127a. The insulating layer 127a is formed in a region sandwiched between any two of the conductive layers 152B, 152G, and 152R, and in a region surrounding the conductive layer 152C. When an acrylic resin is used for the insulating film 127f, an alkaline solution, such as TMAH, can be used as the developer.

[0324] 10B , an etching process is performed using the insulating layer 127a as a mask to remove a portion of the inorganic insulating film 125f and reduce the thickness of a portion of the sacrificial layers 158B, 158G, and 158R. As a result, the inorganic insulating layer 125 is formed below the insulating layer 127a. Note that, hereinafter, the etching process for processing the inorganic insulating film 125f using the insulating layer 127a as a mask may be referred to as a first etching process.

[0325] That is, in the first etching process, the sacrificial layers 158B, 158G, and 158R are not completely removed, and the etching process is stopped when the film thicknesses of the sacrificial layers 158B, 158G, and 158R are reduced. In this manner, by leaving the sacrificial layers 158B, 158G, and 158R on the organic compound layers 103B, 103G, and 103R, respectively, it is possible to prevent the organic compound layers 103B, 103G, and 103R from being damaged in subsequent processes.

[0326] The first etching treatment can be performed by dry etching or wet etching. Note that, when the inorganic insulating film 125f is formed using the same material as the sacrificial layers 158B, 158G, and 158R, the inorganic insulating film 125f can be processed and the exposed sacrificial layer 158 can be thinned in one go by the first etching treatment, which is preferable.

[0327] By performing etching using the insulating layer 127a, which has tapered side surfaces, as a mask, the side surfaces of the inorganic insulating layer 125 and the upper end portions of the side surfaces of the sacrificial layers 158B, 158G, and 158R can be tapered relatively easily.

[0328] For example, when the first etching process is performed by dry etching, a chlorine-based gas can be used. ２ , BCl ３ , SiCl ４ , and CCl ４ The chlorine-based gas may be added with oxygen gas, hydrogen gas, helium gas, argon gas, or the like, either alone or in combination of two or more gases. By using dry etching, thin regions of the sacrificial layers 158B, 158G, and 158R can be formed with good in-plane uniformity.

[0329] Furthermore, for example, the first etching process can be performed by wet etching, which can reduce damage to the organic compound layers 103B, 103G, and 103R compared to when dry etching is used.

[0330] For wet etching, it is preferable to use an acidic chemical solution, such as a chemical solution containing any one of phosphoric acid, hydrofluoric acid, nitric acid, acetic acid, oxalic acid, and sulfuric acid, or a mixed chemical solution of two or more acids (also called mixed acid).

[0331] Alternatively, an alkaline solution can be used for wet etching. For example, TMAH, which is an alkaline solution, can be used for wet etching of an aluminum oxide film. In this case, wet etching can be performed by a paddle method.

[0332] Next, heat treatment (also referred to as post-baking) is performed. By performing the heat treatment, the insulating layer 127a can be transformed into an insulating layer 127 having tapered side surfaces (FIG. 10C). The heat treatment is performed at a temperature lower than the upper temperature limit of the organic compound layer. The heat treatment can be performed at a substrate temperature of 50° C. to 200° C., preferably 60° C. to 150° C., more preferably 70° C. to 130° C. The heating atmosphere may be an air atmosphere or an inert atmosphere. The heating atmosphere may be an atmospheric pressure atmosphere or a reduced-pressure atmosphere. The substrate temperature in the heat treatment in this step is preferably higher than that in the heat treatment (pre-baking) performed after the formation of the insulating film 127f.

[0333] The heat treatment can improve the adhesion between the insulating layer 127 and the inorganic insulating layer 125 and also improve the corrosion resistance of the insulating layer 127. Furthermore, the insulating layer 127a is deformed, so that the end portion of the inorganic insulating layer 125 can be covered with the insulating layer 127.

[0334] By leaving the sacrificial layers 158B, 158G, and 158R in a thinner state without completely removing them in the first etching treatment, the organic compound layers 103B, 103G, and 103R can be prevented from being damaged and deteriorated in the heat treatment, thereby improving the reliability of the light-emitting device.

[0335] 11A , an etching process is performed using the insulating layer 127 as a mask to remove portions of the sacrificial layers 158B, 158G, and 158R. Note that at this time, portions of the inorganic insulating layer 125 may also be removed. By this etching process, openings are formed in the sacrificial layers 158B, 158G, and 158R, and the top surfaces of the organic compound layers 103B, 103G, and 103R, and the conductive layer 152C are exposed through the openings. Note that hereinafter, the etching process that uses the insulating layer 127 as a mask to expose the organic compound layers 103B, 103G, and 103R may be referred to as a second etching process.

[0336] The second etching treatment is performed by wet etching. By using the wet etching method, damage to the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R can be reduced compared to when using the dry etching method. The wet etching can be performed using an acidic chemical solution or an alkaline solution, as in the first etching treatment.

[0337] Furthermore, after exposing portions of the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R, a heat treatment may be further performed. This heat treatment can remove water contained in the organic compound layer and water adsorbed to the surface of the organic compound layer. This heat treatment may also change the shape of the insulating layer 127. Specifically, the insulating layer 127 may extend to cover at least one of the ends of the inorganic insulating layer 125, the ends of the sacrificial layers 158B, 158G, and 158R, and the top surfaces of the organic compound layers 103B, 103G, and 103R.

[0338] Note that Figure 11A shows an example in which a portion of the end of the sacrificial layer 158G (specifically, the tapered portion formed by the first etching process) is covered by the insulating layer 127, and the tapered portion formed by the second etching process is exposed (see Figure 4A).

[0339] The insulating layer 127 may also cover the entire end of the sacrificial layer 158G. For example, the end of the insulating layer 127 may droop and cover the end of the sacrificial layer 158G. For example, the end of the insulating layer 127 may contact the top surface of at least one of the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R.

[0340] 11B , a common electrode 155 is formed on the organic compound layer 103B, the organic compound layer 103G, the organic compound layer 103R, the conductive layer 152C, and the insulating layer 127. The common electrode 155 can be formed by a method such as sputtering or vacuum evaporation. Alternatively, the common electrode 155 may be formed by stacking a film formed by evaporation and a film formed by sputtering.

[0341] 11C, a protective layer 131 is formed on the common electrode 155. The protective layer 131 can be formed by a method such as a vacuum deposition method, a sputtering method, a CVD method, or an ALD method.

[0342] Subsequently, the substrate 120 is attached over the protective layer 131 using the resin layer 122, whereby a light-emitting device can be manufactured. As described above, in the manufacturing method of a light-emitting device according to one embodiment of the present invention, the insulating layer 156 is provided so as to have a region overlapping with a side surface of the conductive layer 151, and the conductive layer 152 is formed so as to cover the conductive layer 151 and the insulating layer 156. This can increase the yield of light-emitting devices and suppress the occurrence of defects.

[0343] As described above, in the manufacturing method of the light-emitting device according to one embodiment of the present invention, the island-shaped organic compound layers 103B, 103G, and 103R are formed by forming films over the entire surface and then processing them, rather than by using a fine metal mask. This allows the island-shaped layers to be formed with uniform thicknesses. This allows a high-resolution light-emitting device or a light-emitting device with a high aperture ratio to be realized. Furthermore, even when the resolution or aperture ratio is high and the distance between subpixels is extremely short, the organic compound layers 103B, 103G, and 103R can be prevented from contacting each other in adjacent subpixels. Therefore, leakage current between subpixels can be suppressed. This prevents crosstalk and realizes a light-emitting device with extremely high contrast. Furthermore, a light-emitting device with excellent characteristics can be provided, even if the light-emitting device includes tandem light-emitting devices fabricated by photolithography.

[0344] Embodiment 4 In this embodiment, a light-emitting device of one embodiment of the present invention will be described with reference to FIGS. 12A to 12G and 13A to 13I.

[0345] [Pixel Layout] In this embodiment, pixel layouts different from that shown in Fig. 3 will be mainly described. There are no particular limitations on the arrangement of sub-pixels, and various methods can be applied. Examples of sub-pixel arrangements include a stripe arrangement, an S-stripe arrangement, a matrix arrangement, a delta arrangement, a Bayer arrangement, and a pentile arrangement.

[0346] The top shape of the sub-pixels shown in the drawings in this embodiment mode corresponds to the top shape of the light-emitting region.

[0347] The top surface shape of the subpixel may be, for example, a triangle, a quadrangle (including a rectangle and a square), a polygon such as a pentagon, a polygon with rounded corners, an ellipse, or a circle.

[0348] Furthermore, the layout of the circuits constituting the sub-pixels is not limited to the range of the sub-pixels shown in the drawings, and may be arranged outside of the range.

[0349] An S-stripe arrangement is applied to the pixel 178 shown in Fig. 12A. The pixel 178 shown in Fig. 12A is composed of three subpixels: a subpixel 110R, a subpixel 110G, and a subpixel 110B.

[0350] 12B includes a subpixel 110R having a generally trapezoidal or triangular top surface shape with rounded corners, a subpixel 110G having a generally trapezoidal or triangular top surface shape with rounded corners, and a subpixel 110B having a generally rectangular or hexagonal top surface shape with rounded corners. Furthermore, the subpixel 110R has a larger light-emitting area than the subpixel 110G. In this manner, the shape and size of each subpixel can be determined independently. For example, the more reliable the light-emitting device, the smaller the size of the subpixel can be.

[0351] The Pentile arrangement is applied to the pixels 124a and 124b shown in Fig. 12C. Fig. 12C shows an example in which the pixel 124a having the subpixel 110R and the subpixel 110G and the pixel 124b having the subpixel 110G and the subpixel 110B are arranged alternately.

[0352] 12D to 12F are arranged in a delta configuration. Pixel 124a has two subpixels (subpixel 110R and subpixel 110G) in the top row (first row) and one subpixel (subpixel 110B) in the bottom row (second row). Pixel 124b has one subpixel (subpixel 110B) in the top row (first row) and two subpixels (subpixel 110R and subpixel 110G) in the bottom row (second row).

[0353] Figure 12D is an example in which each subpixel has an approximately rectangular top surface shape with rounded corners, Figure 12E is an example in which each subpixel has a circular top surface shape, and Figure 12F is an example in which each subpixel has an approximately hexagonal top surface shape with rounded corners.

[0354] 12F, each subpixel is arranged inside a closely packed hexagonal region. Focusing on a single subpixel, each subpixel is arranged so that it is surrounded by six other subpixels. Furthermore, subpixels that emit light of the same color are arranged so that they are not adjacent to each other. For example, focusing on subpixel 110R, three subpixels 110G and three subpixels 110B are arranged alternately to surround it.

[0355] 12G shows an example in which subpixels of each color are arranged in a zigzag pattern. Specifically, when viewed from above, the positions of the upper sides of two subpixels aligned in the column direction (for example, subpixels 110R and 110G, or subpixels 110G and 110B) are misaligned.

[0356] 12A to 12G, it is preferable that the subpixel 110R be the subpixel R that emits red light, the subpixel 110G be the subpixel G that emits green light, and the subpixel 110B be the subpixel B that emits blue light. Note that the configuration of the subpixels is not limited to this, and the colors that the subpixels emit and their order of arrangement can be determined appropriately. For example, the subpixel 110G may be the subpixel R that emits red light, and the subpixel 110R may be the subpixel G that emits green light.

[0357] In photolithography, the finer the pattern to be processed, the more significant the effect of light diffraction becomes. This impairs the fidelity of the photomask pattern when it is transferred by exposure, making it difficult to process the resist mask into the desired shape. Therefore, even if the photomask pattern is rectangular, a pattern with rounded corners is likely to be formed. As a result, the top surface shape of the subpixel may become a polygon with rounded corners, an ellipse, a circle, or the like.

[0358] Furthermore, in a method for manufacturing a light-emitting device according to one embodiment of the present invention, an organic compound layer is processed into an island shape using a resist mask. The resist film formed on the organic compound layer needs to be cured at a temperature lower than the heat resistance temperature of the organic compound layer. Therefore, depending on the heat resistance temperature of the material for the organic compound layer and the curing temperature of the resist material, the resist film may not be cured sufficiently. A resist film that is not cured sufficiently may have a shape that is different from the desired shape during processing. As a result, the top surface shape of the organic compound layer may be a polygon with rounded corners, an ellipse, a circle, or the like. For example, when a resist mask with a square top surface shape is formed, a resist mask with a circular top surface shape may be formed, resulting in a circular top surface shape of the organic compound layer.

[0359] In order to make the top surface of the organic compound layer have a desired shape, a technique for correcting a mask pattern in advance (OPC (Optical Proximity Correction) technique) may be used so that the design pattern and the transfer pattern coincide with each other. Specifically, in the OPC technique, a correction pattern is added to, for example, a corner of a figure on the mask pattern.

[0360] As shown in FIGS. 13A to 13I, a pixel can be configured to have four types of sub-pixels.

[0361] The pixel 178 shown in FIGS. 13A to 13C is arranged in a stripe pattern.

[0362] FIG. 13A shows an example in which each subpixel has a rectangular top surface shape, FIG. 13B shows an example in which each subpixel has a top surface shape that is a combination of two semicircles and a rectangle, and FIG. 13C shows an example in which each subpixel has an elliptical top surface shape.

[0363] The pixels 178 shown in FIGS. 13D to 13F are arranged in a matrix.

[0364] Figure 13D is an example in which each subpixel has a square top surface shape, Figure 13E is an example in which each subpixel has an approximately square top surface shape with rounded corners, and Figure 13F is an example in which each subpixel has a circular top surface shape.

[0365] 13G and 13H show an example in which one pixel 178 is configured in two rows and three columns.

[0366] 13G has three subpixels (subpixels 110R, 110G, and 110B) in the top row (first row) and one subpixel (subpixel 110W) in the bottom row (second row). In other words, pixel 178 has subpixel 110R in the left column (first column), subpixel 110G in the center column (second column), subpixel 110B in the right column (third column), and subpixels 110W across these three columns.

[0367] The pixel 178 shown in FIG. 13H has three subpixels (subpixels 110R, 110G, and 110B) in the top row (first row) and three subpixels 110W in the bottom row (second row). In other words, the pixel 178 has subpixels 110R and 110W in the left column (first column), subpixels 110G and 110W in the center column (second column), and subpixels 110B and 110W in the right column (third column). By aligning the subpixels in the top and bottom rows as shown in FIG. 13H , it becomes possible to efficiently remove dust particles that may occur during the manufacturing process. Therefore, a light-emitting device with high display quality can be provided.

[0368] In the pixel 178 shown in FIGS. 13G and 13H, the subpixels 110R, 110G, and 110B are laid out in a stripe arrangement, which can improve the display quality.

[0369] FIG. 13I shows an example in which one pixel 178 is configured in three rows and two columns.

[0370] 13I has subpixel 110R in the top row (first row), subpixel 110G in the middle row (second row), subpixel 110B across rows 1 and 2, and one subpixel (subpixel 110W) in the bottom row (third row). In other words, pixel 178 has subpixel 110R and subpixel 110G in the left column (first column), subpixel 110B in the right column (second column), and subpixel 110W across these two columns.

[0371] In the pixel 178 shown in FIG. 13I, the layout of the subpixels 110R, 110G, and 110B is a so-called S-stripe arrangement, which can improve the display quality.

[0372] 13A to 13I is composed of four subpixels: subpixel 110R, subpixel 110G, subpixel 110B, and subpixel 110W. For example, subpixel 110R can be a subpixel that emits red light, subpixel 110G can be a subpixel that emits green light, subpixel 110B can be a subpixel that emits blue light, and subpixel 110W can be a subpixel that emits white light. Note that at least one of subpixels 110R, subpixel 110G, subpixel 110B, and subpixel 110W may be a subpixel that emits cyan light, magenta light, yellow light, or near-infrared light.

[0373] As described above, in the light-emitting device of one embodiment of the present invention, various layouts can be applied to pixels each including a subpixel having a light-emitting device.

[0374] This embodiment mode can be combined with other embodiment modes or examples as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0375] Embodiment 5 In this embodiment, a light-emitting device according to one embodiment of the present invention will be described.

[0376] The light emitting device of the present embodiment can be a high-definition light emitting device, and therefore can be used, for example, in the display units of wristwatch-type and bracelet-type information terminals (wearable devices), as well as in the display units of head-mounted wearable devices such as VR devices such as head-mounted displays (HMDs), and eyeglass-type AR devices.

[0377] The light-emitting device of this embodiment can be a high-resolution light-emitting device or a large-sized light-emitting device. Therefore, the light-emitting device of this embodiment can be used in the display portion of electronic devices having relatively large screens, such as television sets, 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, personal digital assistants, and sound reproducing devices.

[0378] 14A shows a perspective view of a display module 280. The display module 280 has a light-emitting device 100A and an FPC 290. Note that the light-emitting device included in the display module 280 is not limited to the light-emitting device 100A, and may be either a light-emitting device 100B or a light-emitting device 100C, which will be described later.

[0379] The display module 280 has a substrate 291 and a substrate 292. The display module 280 has a display portion 281. The display portion 281 is a region that displays an image in the display module 280, and is a region where light from each pixel provided in a pixel portion 284 (described later) can be viewed.

[0380] 14B is a perspective view schematically illustrating the configuration on the substrate 291 side. A circuit portion 282, a pixel circuit portion 283 on the circuit portion 282, and a pixel portion 284 on the pixel circuit portion 283 are stacked on the substrate 291. A terminal portion 285 for connecting to the FPC 290 is provided in a portion of the substrate 291 that does not overlap with the pixel portion 284. The terminal portion 285 and the circuit portion 282 are electrically connected by a wiring portion 286 composed of a plurality of wirings.

[0381] The pixel section 284 has a plurality of periodically arranged pixels 284a. An enlarged view of one pixel 284a is shown on the right side of Fig. 14B. The various configurations described in the previous embodiments can be applied to the pixel 284a. Fig. 14B shows an example in which the pixel 284a has the same configuration as the pixel 178 shown in Fig. 3.

[0382] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0383] One pixel circuit 283a is a circuit that controls the driving of multiple elements included in one pixel 284a. One pixel circuit 283a can be configured to have three circuits that control the light emission of one light-emitting device. For example, the pixel circuit 283a can be configured to have at least one selection transistor, one current control transistor (drive transistor), and a capacitor for each light-emitting device. In this case, a gate signal is input to the gate of the selection transistor, and a video signal is input to the source or drain. This realizes an active matrix light-emitting device.

[0384] The circuit portion 282 includes a circuit for driving each pixel circuit 283 a of the pixel circuit portion 283. For example, the circuit portion 282 preferably includes one or both of a gate line driver circuit and a source line driver circuit. In addition, the circuit portion 282 may include at least one of an arithmetic circuit, a memory circuit, a power supply circuit, and the like.

[0385] The FPC 290 functions as wiring for supplying a video signal, a power supply potential, or the like from the outside to the circuit portion 282. An IC may be mounted on the FPC 290.

[0386] The display module 280 can be configured such that one or both of the pixel circuit unit 283 and the circuit unit 282 are stacked below the pixel unit 284, thereby enabling the aperture ratio (effective display area ratio) of the display unit 281 to be extremely high. For example, the aperture ratio of the display unit 281 can be 40% or more and less than 100%, preferably 50% or more and 95% or less, and more preferably 60% or more and 95% or less. Furthermore, the pixels 284a can be arranged at an extremely high density, enabling the resolution of the display unit 281 to be extremely high. For example, it is preferable that the pixels 284a be arranged in the display unit 281 at a resolution of 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and 20000 ppi or less, or 30000 ppi or less.

[0387] Because such a display module 280 has extremely high resolution, it can be suitably used in VR devices such as HMDs or eyeglass-type AR devices. For example, even in a configuration in which the display unit of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display unit 281, so even if the display unit is enlarged with lenses, the pixels are not visible, allowing for a highly immersive display. Furthermore, the display module 280 is not limited to this, and can be suitably used in electronic devices with relatively small display units. For example, it can be suitably used in the display unit of a wearable electronic device such as a wristwatch.

[0388] Light-Emitting Device 100A The light-emitting device 100A shown in FIG. 15A includes a substrate 301, a light-emitting device 130R, a light-emitting device 130G, a light-emitting device 130B, a capacitor 240, and a transistor 310.

[0389] The substrate 301 corresponds to the substrate 291 in FIGS. 14A and 14B . The transistor 310 is a transistor having a channel formation region in the substrate 301. The substrate 301 can be, for example, a semiconductor substrate such as a single crystal silicon substrate. The transistor 310 includes a part of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region in which the substrate 301 is doped with impurities and functions as a source or drain. The insulating layer 314 is provided to cover a side surface of the conductive layer 311.

[0390] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301 .

[0391] In addition, an insulating layer 261 is provided to cover the transistor 310 , and a capacitor 240 is provided over the insulating layer 261 .

[0392] The capacitor 240 has a conductive layer 241, a conductive layer 245, and an insulating layer 243 located therebetween. The conductive layer 241 functions as one electrode of the capacitor 240, the conductive layer 245 functions as the other electrode of the capacitor 240, and the insulating layer 243 functions as a dielectric of the capacitor 240.

[0393] The conductive layer 241 is provided over the insulating layer 261 and is buried in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source and the drain of the transistor 310 by a plug 271 buried in the insulating layer 261. The insulating layer 243 is provided to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping with the conductive layer 241 with the insulating layer 243 interposed therebetween.

[0394] An insulating layer 255 is provided covering the capacitor 240, an insulating layer 174 is provided on the insulating layer 255, and an insulating layer 175 is provided on the insulating layer 174. Light-emitting device 130R, light-emitting device 130G, and light-emitting device 130B are provided on the insulating layer 175. FIG. 15A shows an example in which light-emitting device 130R, light-emitting device 130G, and light-emitting device 130B have the stacked structure shown in FIG. 1A. An insulator is provided in the region between adjacent light-emitting devices. For example, in FIG. 15A, an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 are provided in this region.

[0395] Insulating layer 156R is provided to have a region overlapping with a side surface of conductive layer 151R of light-emitting device 130R, insulating layer 156G is provided to have a region overlapping with a side surface of conductive layer 151G of light-emitting device 130G, and insulating layer 156B is provided to have a region overlapping with a side surface of conductive layer 151B of light-emitting device 130B. Furthermore, conductive layer 152R is provided to cover conductive layer 151R and insulating layer 156R, conductive layer 152G is provided to cover conductive layer 151G and insulating layer 156G, and conductive layer 152B is provided to cover conductive layer 151B and insulating layer 156B. Furthermore, a sacrificial layer 158R is located on the organic compound layer 103R of the light-emitting device 130R, a sacrificial layer 158G is located on the organic compound layer 103G of the light-emitting device 130G, and a sacrificial layer 158B is located on the organic compound layer 103B of the light-emitting device 130B.

[0396] The conductive layer 151R, the conductive layer 151G, and the conductive layer 151B are electrically connected to one of the source and drain of the transistor 310 via an insulating layer 243, an insulating layer 255, an insulating layer 174, a plug 256 embedded in the insulating layer 175, a conductive layer 241 embedded in the insulating layer 254, and a plug 271 embedded in the insulating layer 261. The height of the top surface of the insulating layer 175 and the height of the top surface of the plug 256 are the same or approximately the same. Various conductive materials can be used for the plug.

[0397] Furthermore, a protective layer 131 is provided on the light-emitting devices 130R, 130G, and 130B. A substrate 120 is bonded to the protective layer 131 with a resin layer 122. For details of the components from the light-emitting device 130 to the substrate 120, refer to embodiment 3. The substrate 120 corresponds to the substrate 292 in FIG. 14A .

[0398] Fig. 15B is a modified example of the light-emitting device 100A shown in Fig. 15A. The light-emitting device shown in Fig. 15B has a colored layer 132R, a colored layer 132G, and a colored layer 132B, and the light-emitting device 130 has an area where it overlaps with one of the colored layers 132R, 132G, and 132B. In the light-emitting device shown in Fig. 15B, the light-emitting device 130 can emit, for example, white light. Furthermore, for example, the colored layer 132R can transmit red light, the colored layer 132G can transmit green light, and the colored layer 132B can transmit blue light.

[0399] [Light Emitting Device 100B] FIG. 16 shows a perspective view of light emitting device 100B, and FIG. 17A shows a cross-sectional view of light emitting device 100B.

[0400] The light emitting device 100B has a configuration in which a substrate 352 and a substrate 351 are bonded together. In Fig. 16, the substrate 352 is clearly indicated by a dashed line.

[0401] The light-emitting device 100B has a pixel portion 177, a connection portion 140, a circuit 356, wiring 355, and the like. Fig. 16 shows an example in which an IC (integrated circuit) 354 and an FPC 353 are mounted on the light-emitting device 100B. Therefore, the configuration shown in Fig. 16 can also be called a display module having the light-emitting device 100B, an IC, and an FPC. Here, a light-emitting device in which a connector such as an FPC is attached to a substrate, or a light-emitting device in which an IC is mounted on the substrate, is called a display module.

[0402] The connection portion 140 is provided outside the pixel portion 177. The connection portion 140 can be provided along one side or multiple sides of the pixel portion 177. The number of connection portions 140 may be single or multiple. Fig. 16 shows an example in which the connection portion 140 is provided so as to surround the four sides of the pixel portion 177. The connection portion 140 electrically connects the common electrode of the light-emitting device and the conductive layer, and can supply a potential to the common electrode.

[0403] The circuit 356 can be, for example, a scanning line driver circuit.

[0404] The wiring 355 has a function of supplying signals and power to the pixel portion 177 and the circuit 356. The signals and power are input to the wiring 355 from the outside via the FPC 353 or from the IC 354.

[0405] 16 shows an example in which an IC 354 is provided on a substrate 351 by a chip-on-glass (COG) method, a chip-on-film (COF) method, or the like. The IC 354 may be, for example, an IC having a scanning line driver circuit or a signal line driver circuit. The light-emitting device 100B and the display module may not necessarily include an IC. Alternatively, the IC may be mounted on an FPC by a COF method, for example.

[0406] Figure 17A shows an example of a cross section of the light-emitting device 100B, where a portion of the region including the FPC 353, a portion of the circuit 356, a portion of the pixel portion 177, a portion of the connection portion 140, and a portion of the region including the end portion are cut.

[0407] The light-emitting device 100B shown in Figure 17A has, between a substrate 351 and a substrate 352, a transistor 201, a transistor 205, a light-emitting device 130R that emits red light, a light-emitting device 130G that emits green light, and a light-emitting device 130B that emits blue light.

[0408] The light emitting devices 130R, 130G, and 130B each have the same layered structure as shown in Fig. 1A, except that the configuration of the pixel electrodes is different. For details of the light emitting devices, refer to the previous embodiment.

[0409] Light-emitting device 130R has conductive layer 224R, conductive layer 151R on conductive layer 224R, and conductive layer 152R on conductive layer 151R. Light-emitting device 130G has conductive layer 224G, conductive layer 151G on conductive layer 224G, and conductive layer 152G on conductive layer 151G. Light-emitting device 130B has conductive layer 224B, conductive layer 151B on conductive layer 224B, and conductive layer 152B on conductive layer 151B. Here, conductive layer 224R, conductive layer 151R, and conductive layer 152R may be collectively referred to as the pixel electrode of light-emitting device 130R, and conductive layer 151R and conductive layer 152R excluding conductive layer 224R may be referred to as the pixel electrode of light-emitting device 130R. Similarly, conductive layer 224G, conductive layer 151G, and conductive layer 152G may be collectively referred to as the pixel electrode of light-emitting device 130G, and conductive layer 151G and conductive layer 152G excluding conductive layer 224G may be collectively referred to as the pixel electrode of light-emitting device 130G. Furthermore, conductive layer 224B, conductive layer 151B, and conductive layer 152B may be collectively referred to as the pixel electrode of light-emitting device 130B, and conductive layer 151B and conductive layer 152B excluding conductive layer 224B may be collectively referred to as the pixel electrode of light-emitting device 130B.

[0410] The conductive layer 224R is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214. An end of the conductive layer 151R is located outside an end of the conductive layer 224R. An insulating layer 156R is provided to have a region in contact with the side surface of the conductive layer 151R, and a conductive layer 152R is provided to cover the conductive layer 151R and the insulating layer 156R.

[0411] Conductive layer 224G, conductive layer 151G, conductive layer 152G, and insulating layer 156G in light-emitting device 130G, and conductive layer 224B, conductive layer 151B, conductive layer 152B, and insulating layer 156B in light-emitting device 130B are similar to conductive layer 224R, conductive layer 151R, conductive layer 152R, and insulating layer 156R in light-emitting device 130R, and therefore detailed description thereof will be omitted.

[0412] Recesses are formed in the conductive layers 224R, 224G, and 224B so as to cover the openings provided in the insulating layer 214. A layer 128 is buried in the recesses.

[0413] The layer 128 has a function of planarizing the recesses of the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B. The conductive layer 151R, the conductive layer 151G, and the conductive layer 151B, which are electrically connected to the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B, are provided on the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B and the layer 128. Therefore, the regions overlapping with the recesses of the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B can also be used as light-emitting regions, thereby increasing the aperture ratio of the pixel.

[0414] The layer 128 may be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be used as appropriate for the layer 128. In particular, the layer 128 is preferably formed using an insulating material, and more preferably using an organic insulating material. For example, the organic insulating material that can be used for the insulating layer 127 described above can be used for the layer 128.

[0415] A protective layer 131 is provided on the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B. The protective layer 131 and the substrate 352 are bonded via an adhesive layer 142. A light-shielding layer 157 is provided on the substrate 352. A solid sealing structure, a hollow sealing structure, or the like can be applied to seal the light-emitting device 130. In FIG. 17A , the space between the substrate 352 and the substrate 351 is filled with the adhesive layer 142, and a solid sealing structure is applied. Alternatively, the space may be filled with an inert gas (such as nitrogen or argon), and a hollow sealing structure may be applied. In this case, the adhesive layer 142 may be provided so as not to overlap the light-emitting device. Alternatively, the space may be filled with a resin different from the frame-shaped adhesive layer 142.

[0416] 17A shows an example in which connection portion 140 has conductive layer 224C obtained by processing the same conductive film as conductive layers 224R, 224G, and 224B, conductive layer 151C obtained by processing the same conductive film as conductive layers 151R, 151G, and 151B, and conductive layer 152C obtained by processing the same conductive film as conductive layers 152R, 152G, and 152B. Also, FIG. 17A shows an example in which insulating layer 156C is provided so as to have a region overlapping with a side surface of conductive layer 151C.

[0417] The light-emitting device 100B is a top-emission type. Light emitted by the light-emitting device is emitted toward the substrate 352. The substrate 352 is preferably made of a material that is highly transparent to visible light. The pixel electrode contains a material that reflects visible light, and the counter electrode (common electrode 155) contains a material that transmits visible light.

[0418] The transistor 201 and the transistor 205 are both formed over a substrate 351. These transistors can be manufactured using the same material and through the same process.

[0419] An insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are provided over the substrate 351 in this order. A part of the insulating layer 211 functions as a gate insulating layer for each transistor. A part of the insulating layer 213 functions as a gate insulating layer for each transistor. The insulating layer 215 is provided to cover the transistor. The insulating layer 214 is provided to cover the transistor and functions as a planarization layer. Note that the number of gate insulating layers and the number of insulating layers covering the transistors are not limited, and each may be a single layer or two or more layers.

[0420] It is preferable that at least one insulating layer covering the transistor is made of a material that is resistant to the diffusion of impurities such as water and hydrogen. This allows the insulating layer to function as a barrier layer. With this structure, it is possible to effectively prevent impurities from diffusing into the transistor from the outside, thereby improving the reliability of the light-emitting device.

[0421] It is preferable to use an inorganic insulating film for each of the insulating layers 211, 213, and 215. Examples of the inorganic insulating film that can be used include a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum oxide film, and an aluminum nitride film. Alternatively, 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 may also be used. Two or more of the above insulating films may be stacked.

[0422] An organic insulating layer is suitable for the insulating layer 214, which functions as a planarizing layer. Materials that can be used for the organic insulating layer include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimideamide resin, siloxane resin, benzocyclobutene-based resin, phenolic resin, and precursors of these resins. Alternatively, the insulating layer 214 may have a laminated structure of an organic insulating layer and an inorganic insulating layer. The outermost layer of the insulating layer 214 preferably functions as an etching protection layer. This prevents recesses from being formed in the insulating layer 214 during processing of the conductive layer 224R, conductive layer 151R, conductive layer 152R, etc. Alternatively, recesses may be formed in the insulating layer 214 during processing of the conductive layer 224R, conductive layer 151R, conductive layer 152R, etc.

[0423] The transistor 201 and the transistor 205 each include a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as a source and a drain, a semiconductor layer 231, an insulating layer 213 that functions as a gate insulating layer, and a conductive layer 223 that functions as a gate. Here, the same hatching pattern is applied to multiple layers obtained by processing the same conductive film. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

[0424] The structure of the transistor included in the light-emitting device of this embodiment is not particularly limited. For example, a planar transistor, a staggered transistor, an inverted staggered transistor, or the like can be used. Furthermore, either a top-gate transistor or a bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below a semiconductor layer in which a channel is formed.

[0425] The transistor 201 and the transistor 205 have a structure in which a semiconductor layer in which a channel is formed is sandwiched between two gates. The two gates may be connected and the same signal may be supplied to drive the transistor. Alternatively, the threshold voltage of the transistor may be controlled by applying a potential for controlling the threshold voltage to one of the two gates and a potential for driving to the other.

[0426] 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.

[0427] A semiconductor layer of the transistor preferably contains a metal oxide. That is, the light-emitting device of this embodiment preferably uses a transistor in which a channel formation region is formed using a metal oxide (hereinafter referred to as an OS transistor).

[0428] Examples of crystalline oxide semiconductors include c-axis-aligned crystalline (CAAC)-OS, nanocrystalline (nc)-OS, and the like.

[0429] Alternatively, a transistor using silicon for a channel formation region (Si transistor) may be used. 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) may be used. An LTPS transistor has high field-effect mobility and favorable frequency characteristics.

[0430] 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.

[0431] 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.

[0432] Furthermore, to increase the light 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 light emission luminance of the light-emitting device.

[0433] Furthermore, in terms of the 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.

[0434] 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.

[0435] The semiconductor layer preferably contains, for example, indium, M (wherein 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.

[0436] In particular, it is preferable to use an oxide containing indium (In), gallium (Ga), and zinc (Zn) (also referred to as IGZO) as the semiconductor layer. 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).

[0437] When the semiconductor layer 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. Examples of atomic ratios of metal elements in such In-M-Zn oxides include a composition in which In:M:Zn = 1:1:1 or thereabouts, a composition in which In:M:Zn = 1:1:1.2 or thereabouts, a composition in which In:M:Zn = 2:1:3 or thereabouts, a composition in which In:M:Zn = 3:1:2 or thereabouts, a composition in which In:M:Zn = 4:2:3 or thereabouts, a composition in which In:M:Zn = 4:2:4.1 or thereabouts, a composition in which In:M:Zn = 5:1:3 or thereabouts, a composition in which In:M:Zn = 5:1:6 or thereabouts, a composition in which In:M:Zn = 5:1:7 or thereabouts, a composition in which In:M:Zn = 5:1:8 or thereabouts, a composition in which In:M:Zn = 6:1:6 or thereabouts, and a composition in which In:M:Zn = 5:2:5 or thereabouts. The term "nearby composition" includes a range of ±30% of the desired atomic ratio.

[0438] 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.

[0439] The transistors included in the circuit 356 and the transistors included in the pixel portion 177 may have the same structure or different structures. The transistors included in the circuit 356 may all have the same structure or may have two or more types. Similarly, the transistors included in the pixel portion 177 may all have the same structure or may have two or more types.

[0440] All the transistors included in the pixel portion 177 may be OS transistors, all the transistors included in the pixel portion 177 may be Si transistors, or some of the transistors included in the pixel portion 177 may be OS transistors and the rest may be Si transistors.

[0441] For example, by using both an LTPS transistor and an OS transistor in the pixel portion 177, a light-emitting device with low power consumption and high driving capability can be realized. A structure in which an LTPS transistor and an OS transistor are combined is sometimes referred to as LTPO. Note that, for example, it is preferable to use an OS transistor as a transistor that functions as a switch for controlling the conduction / non-conduction of a wiring, and to use an LTPS transistor as a transistor for controlling current.

[0442] For example, one of the transistors included in the pixel portion 177 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.

[0443] On the other hand, another transistor included in the pixel portion 177 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), thereby reducing power consumption by stopping the driver when displaying a still image.

[0444] As described above, the light-emitting device of one embodiment of the present invention can have a high aperture ratio, high definition, high display quality, and low power consumption.

[0445] Note that a light-emitting device according to one embodiment of the present invention includes an OS transistor and a light-emitting device with an MML (metal maskless) structure. This structure can significantly reduce leakage current that may flow through the transistor and leakage current that may flow between adjacent light-emitting devices (also referred to as lateral leakage current). Furthermore, with this structure, when an image is displayed on the light-emitting 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 the transistor and lateral leakage current between light-emitting devices are extremely low can minimize light leakage during black display (so-called floating black).

[0446] In particular, among light-emitting devices with an MML structure, by applying the SBS (Side By Side) structure, which is a structure in which the light-emitting layers are separately fabricated or separately painted as described above, layers provided between light-emitting devices (for example, organic layers shared between light-emitting devices, also called common layers) are configured to be separated, and therefore side leakage can be eliminated or made extremely small.

[0447] 17B and 17C show other examples of transistor configurations.

[0448] The transistor 209 and the transistor 210 each include a conductive layer 221 functioning as a gate, an insulating layer 211 functioning as a gate insulating layer, a semiconductor layer 231 including a channel formation region 231i and a pair of low-resistance regions 231n, a conductive layer 222a connected to one of the pair of low-resistance regions 231n, a conductive layer 222b connected to the other of the pair of low-resistance regions 231n, an insulating layer 225 functioning as a gate insulating layer, a conductive layer 223 functioning as a gate, and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel formation region 231i. The insulating layer 225 is located at least between the conductive layer 223 and the channel formation region 231i. Furthermore, an insulating layer 218 covering the transistor may be provided.

[0449] 17B shows an example in which the insulating layer 225 covers the top surface and side surfaces of the semiconductor layer 231. The conductive layer 222a and the conductive layer 222b are connected to the low-resistance region 231n through openings provided in the insulating layer 225 and the insulating layer 215, respectively. One of the conductive layer 222a and the conductive layer 222b functions as a source, and the other functions as a drain.

[0450] 17C , the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231 but does not overlap with the low-resistance region 231n. For example, the insulating layer 225 is processed using the conductive layer 223 as a mask, thereby manufacturing the structure shown in FIG. 17C . In FIG. 17C , the insulating layer 215 is provided to cover the insulating layer 225 and the conductive layer 223, and the conductive layer 222a and the conductive layer 222b are connected to the low-resistance region 231n through openings in the insulating layer 215.

[0451] A connection portion 204 is provided in a region of the substrate 351 where the substrate 352 does not overlap. In the connection portion 204, a wiring 355 is electrically connected to the FPC 353 via a conductive layer 166 and a connection layer 242. The conductive layer 166 has an example of a stacked structure including a conductive film obtained by processing the same conductive film as the conductive layers 224R, 224G, and 224B, a conductive film obtained by processing the same conductive film as the conductive layers 151R, 151G, and 151B, and a conductive film obtained by processing the same conductive film as the conductive layers 152R, 152G, and 152B. The conductive layer 166 is exposed on the top surface of the connection portion 204. This allows the connection portion 204 and the FPC 353 to be electrically connected via the connection layer 242.

[0452] It is preferable to provide a light-shielding layer 157 on the surface of the substrate 352 facing the substrate 351. The light-shielding layer 157 can be provided between adjacent light-emitting devices, on the connection section 140, on the circuit 356, etc. In addition, various optical members can be arranged on the outside of the substrate 352.

[0453] The materials that can be used for the substrate 120 can be used for the substrate 351 and the substrate 352 .

[0454] The adhesive layer 142 can be made of a material that can be used for the resin layer 122 .

[0455] The connection layer 242 may be an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like.

[0456] [Light Emitting Device 100H] The light emitting device 100H shown in FIG. 18 differs from the light emitting device 100B shown in FIG. 17A mainly in that it is a bottom emission type light emitting device.

[0457] Light emitted from the light-emitting device is emitted toward the substrate 351. A material that is highly transparent to visible light is preferably used for the substrate 351. On the other hand, the light-transmitting property of the material used for the substrate 352 does not matter.

[0458] A light-shielding layer 157 is preferably formed between the substrate 351 and the transistor 201 and between the substrate 351 and the transistor 205. Figure 18 shows an example in which the light-shielding layer 157 is provided over the substrate 351, the insulating layer 153 is provided over the light-shielding layer 157, and the transistors 201, 205, and the like are provided over the insulating layer 153.

[0459] Light emitting device 130R includes conductive layer 112R, conductive layer 126R on conductive layer 112R, and conductive layer 129R on conductive layer 126R.

[0460] Light emitting device 130B includes conductive layer 112B, conductive layer 126B on conductive layer 112B, and conductive layer 129B on conductive layer 126B.

[0461] The conductive layers 112R, 112B, 126R, 126B, 129R, and 129B are made of a material that is highly transparent to visible light. The common electrode 155 is preferably made of a material that reflects visible light.

[0462] Although the light emitting device 130G is not shown in FIG. 18, the light emitting device 130G is also provided.

[0463] Although FIG. 18 and other figures show an example in which the top surface of the layer 128 has a flat portion, the shape of the layer 128 is not particularly limited.

[0464] [Light Emitting Device 100C] The light emitting device 100C shown in FIG. 19A is a modification of the light emitting device 100B shown in FIG. 17A, and differs from the light emitting device 100B mainly in that it has colored layers 132R, 132G, and 132B.

[0465] In the light-emitting device 100C, the light-emitting device 130 has an area overlapping one of the colored layers 132R, 132G, and 132B. The colored layers 132R, 132G, and 132B can be provided on the surface of the substrate 352 facing the substrate 351. An end of the colored layer 132R, an end of the colored layer 132G, and an end of the colored layer 132B can overlap the light-shielding layer 157.

[0466] In the light-emitting device 100C, the light-emitting device 130 can emit, for example, white light. Furthermore, for example, the colored layer 132R can transmit red light, the colored layer 132G can transmit green light, and the colored layer 132B can transmit blue light. The light-emitting device 100C may be configured such that the colored layers 132R, 132G, and 132B are provided between the protective layer 131 and the adhesive layer 142.

[0467] 17A and 19A show examples in which the top surface of the layer 128 has a flat portion, but there are no particular limitations on the shape of the layer 128. Modified examples of the layer 128 are shown in Figures 19B to 19D.

[0468] 19B and 19D, the upper surface of layer 128 may have a shape with a recess in the center and its vicinity in cross section, i.e., a shape with a concave curve. In addition, common layer 154 may be provided so as to contact common electrode 155.

[0469] As shown in FIG. 19C, the upper surface of layer 128 may be configured to have a shape in which the center and its vicinity bulge in cross section, that is, a shape having a convex curve.

[0470] The upper surface of layer 128 may have one or both of a convex curved surface and a concave curved surface. The number of convex curved surfaces and the number of concave curved surfaces that the upper surface of layer 128 has are not limited, and may be one or more.

[0471] Furthermore, the height of the upper surface of layer 128 and the height of the upper surface of conductive layer 224R may be the same or approximately the same, or may be different from each other. For example, the height of the upper surface of layer 128 may be lower or higher than the height of the upper surface of conductive layer 224R.

[0472] 19B can also be considered an example in which layer 128 is contained within a recess formed in conductive layer 224R. On the other hand, as shown in FIG. 19D, layer 128 may be present outside the recess formed in conductive layer 224R, that is, the width of the top surface of layer 128 may be wider than the recess.

[0473] This embodiment mode can be combined with other embodiment modes or examples as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0474] Embodiment 6 In this embodiment, an electronic device according to one embodiment of the present invention will be described.

[0475] The electronic devices of this embodiment include the light-emitting device of one embodiment of the present invention in their display portions. The light-emitting device of one embodiment of the present invention is highly reliable and can easily achieve high definition and high resolution. Therefore, the light-emitting device can be used in the display portions of various electronic devices.

[0476] Examples of electronic devices include electronic devices with relatively large screens such as television sets, desktop or notebook personal computers, computer monitors, digital signage, large game machines such as pachinko machines, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and sound playback devices.

[0477] In particular, the light-emitting device of one embodiment of the present invention can have high resolution and thus can be suitably used in electronic devices having a relatively small display portion. Examples of such electronic devices include wristwatch-type and bracelet-type information terminals (wearable devices), and head-mounted wearable devices such as VR devices such as head-mounted displays, AR glasses-type devices, and MR devices.

[0478] The light-emitting device of one embodiment of the present invention preferably has extremely high resolution, such as HD (1280 × 720 pixels), FHD (1920 × 1080 pixels), WQHD (2560 × 1440 pixels), WQXGA (2560 × 1600 pixels), 4K (3840 × 2160 pixels), or 8K (7680 × 4320 pixels). A resolution of 4K, 8K, or higher is particularly preferable. Furthermore, the pixel density (resolution) of the light-emitting device of one embodiment of the present invention is preferably 100 ppi or higher, more preferably 300 ppi or higher, more preferably 500 ppi or higher, more preferably 1000 ppi or higher, more preferably 2000 ppi or higher, more preferably 3000 ppi or higher, more preferably 5000 ppi or higher, and even more preferably 7000 ppi or higher. By using a light-emitting device having either or both of high resolution and high definition, it is possible to further enhance the sense of realism and depth in electronic devices for personal use, such as portable or home use. Furthermore, the screen ratio (aspect ratio) of the light-emitting device of one embodiment of the present invention is not particularly limited. For example, the light-emitting device can be used with various screen ratios such as 1:1 (square), 4:3, 16:9, and 16:10.

[0479] The electronic device of this embodiment may have a sensor (including a function to measure force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays).

[0480] The electronic device of the present embodiment can have various functions, such as a function to display various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function to display a calendar, date, time, etc., a function to execute various software (programs), a wireless communication function, and a function to read out programs or data recorded on a recording medium.

[0481] 20A to 20D , examples of wearable devices that can be worn on the head are described. These wearable devices have at least one of the following functions: a function to display AR content, a function to display VR content, a function to display SR content, and a function to display MR content. By having an electronic device with the function to display at least one of AR, VR, SR, and MR content, it is possible to enhance the sense of immersion felt by the user.

[0482] The electronic device 700A shown in FIG. 20A and the electronic device 700B shown in FIG. 20B each have a pair of display panels 751, a pair of housings 721, a communication unit (not shown), a pair of mounting units 723, a control unit (not shown), an imaging unit (not shown), a pair of optical members 753, a frame 757, and a pair of nose pads 758.

[0483] The light-emitting device of one embodiment of the present invention can be applied to the display panel 751. Therefore, the electronic device can be highly reliable.

[0484] The electronic device 700A and the electronic device 700B can each project an image displayed on the display panel 751 onto a display area 756 of the optical member 753. Because the optical member 753 is translucent, the user can see the image displayed in the display area superimposed on a transmitted image visually recognized through the optical member 753. Therefore, the electronic device 700A and the electronic device 700B are each electronic devices capable of AR display.

[0485] The electronic device 700A and the electronic device 700B may be provided with a camera capable of capturing an image in front of them as an imaging unit. Furthermore, the electronic device 700A and the electronic device 700B may each be provided with an acceleration sensor such as a gyro sensor, thereby detecting the orientation of the user's head and displaying an image corresponding to that orientation in the display area 756.

[0486] The communication unit has a wireless communication device, and can supply, for example, a video signal via the wireless communication device. Note that instead of or in addition to the wireless communication device, a connector to which a cable through which a video signal and a power supply potential can be connected may be provided.

[0487] Furthermore, the electronic device 700A and the electronic device 700B are provided with batteries, which can be charged wirelessly and / or wired.

[0488] The housing 721 may be provided with a touch sensor module. The touch sensor module has a function of detecting a touch on the outer surface of the housing 721. The touch sensor module detects a tap operation, a slide operation, or the like by the user and can perform various processes. For example, a tap operation can perform a process such as pausing or resuming a video, and a slide operation can perform a process such as fast-forwarding or fast-rewinding. Furthermore, providing a touch sensor module on each of the two housings 721 can expand the range of operations.

[0489] Various touch sensors can be used as the touch sensor module. For example, various types of touch sensors can be used, such as a capacitance type, a resistive film type, an infrared type, an electromagnetic induction type, a surface acoustic wave type, or an optical type. In particular, it is preferable to use a capacitance type or an optical type sensor in the touch sensor module.

[0490] When an optical touch sensor is used, a photoelectric conversion device (also called a photoelectric conversion element) can be used as the light receiving element. The active layer of the photoelectric conversion device can be made of either or both of an inorganic semiconductor and an organic semiconductor.

[0491] The electronic device 800A shown in Figure 20C and the electronic device 800B shown in Figure 20D each have a pair of display units 820, a housing 821, a communication unit 822, a pair of mounting units 823, a control unit 824, a pair of imaging units 825, and a pair of lenses 832.

[0492] The light-emitting device of one embodiment of the present invention can be applied to the display portion 820. Therefore, the electronic device can have high reliability.

[0493] The display unit 820 is provided inside the housing 821 at a position that can be viewed through the lens 832. In addition, by displaying different images on the pair of display units 820, it is possible to perform three-dimensional display using parallax.

[0494] The electronic device 800A and the electronic device 800B can be said to be electronic devices for VR. A user wearing the electronic device 800A or the electronic device 800B can view an image displayed on the display unit 820 through the lens 832.

[0495] It is preferable that electronic device 800A and electronic device 800B each have a mechanism that can adjust the left and right positions of lens 832 and display unit 820 so that they are optimally positioned according to the position of the user's eyes. It is also preferable that electronic device 800A and electronic device 800B each have a mechanism that can adjust the focus by changing the distance between lens 832 and display unit 820.

[0496] The mounting unit 823 allows the user to wear the electronic device 800A or the electronic device 800B on the head. Note that, for example, in Fig. 20C, the mounting unit 823 is shaped like the temples of glasses (also called joints or temples), but is not limited to this. The mounting unit 823 may be shaped like a helmet or a band, for example, as long as it can be worn by the user.

[0497] The imaging unit 825 has a function of acquiring external information. Data acquired by the imaging unit 825 can be output to the display unit 820. An image sensor can be used for the imaging unit 825. Furthermore, multiple cameras may be provided to support multiple angles of view, such as telephoto and wide-angle.

[0498] Although an example including the imaging unit 825 is shown here, a distance measuring sensor (hereinafter also referred to as a detection unit) capable of measuring the distance to an object may be provided. That is, the imaging unit 825 is one aspect of the detection unit. As the detection unit, for example, an image sensor or a range image sensor such as a LIDAR (Light Detection and Ranging) can be used. By using an image obtained by the camera and an image obtained by the range image sensor, more information can be obtained, enabling more accurate gesture operations.

[0499] The electronic device 800A may have a vibration mechanism that functions as a bone conduction earphone. For example, a configuration having such a vibration mechanism can be applied to one or more of the display unit 820, the housing 821, and the wearing unit 823. This allows a user to enjoy video and audio simply by wearing the electronic device 800A, without the need for separate audio equipment such as headphones, earphones, or speakers.

[0500] The electronic device 800A and the electronic device 800B may each have an input terminal to which a cable can be connected for supplying a video signal from a video output device or the like and power for charging a battery provided in the electronic device.

[0501] The electronic device of one embodiment of the present invention may have a function of wireless communication with an earphone 750. The earphone 750 includes a communication unit (not shown) and has a wireless communication function. The earphone 750 can receive information (e.g., audio data) from the electronic device through the wireless communication function. For example, the electronic device 700A shown in FIG. 20A has a function of transmitting information to the earphone 750 through the wireless communication function. Furthermore, for example, the electronic device 800A shown in FIG. 20C has a function of transmitting information to the earphone 750 through the wireless communication function.

[0502] The electronic device may also have an earphone unit. Electronic device 700B shown in Fig. 20B has earphone unit 727. For example, earphone unit 727 and the control unit may be configured to be connected to each other by wire. Part of the wiring connecting earphone unit 727 and the control unit may be disposed inside housing 721 or attachment unit 723.

[0503] Similarly, electronic device 800B shown in Fig. 20D has earphone unit 827. For example, earphone unit 827 and control unit 824 can be configured to be connected to each other by wire. Part of the wiring connecting earphone unit 827 and control unit 824 may be disposed inside housing 821 or wearing unit 823. Furthermore, earphone unit 827 and wearing unit 823 may have magnets. This allows earphone unit 827 to be fixed to wearing unit 823 by magnetic force, which is preferable as it makes storage easier.

[0504] The electronic device may have an audio output terminal to which earphones or headphones can be connected. The electronic device may also have one or both of an audio input terminal and an audio input mechanism. For example, a sound collection device such as a microphone can be used as the audio input mechanism. By having the audio input mechanism, the electronic device may be endowed with the functionality of a so-called headset.

[0505] As described above, as electronic devices according to one embodiment of the present invention, both glasses-type devices (such as the electronic devices 700A and 700B) and goggle-type devices (such as the electronic devices 800A and 800B) are suitable.

[0506] Furthermore, the electronic device according to one embodiment of the present invention can transmit information to the earphone via a wired or wireless connection.

[0507] The electronic device 6500 shown in FIG. 21A is a portable information terminal that can be used as a smartphone.

[0508] The electronic device 6500 includes a housing 6501, a display portion 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, a light source 6508, and the like. The display portion 6502 has a touch panel function.

[0509] The light-emitting device of one embodiment of the present invention can be applied to the display portion 6502. Therefore, the electronic device can have high reliability.

[0510] FIG. 21B is a schematic cross-sectional view including the end of the housing 6501 on the microphone 6506 side.

[0511] A light-transmitting protective member 6510 is provided on the display surface side of the housing 6501, and a display panel 6511, an optical member 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc. are arranged in the space surrounded by the housing 6501 and the protective member 6510.

[0512] A display panel 6511, an optical member 6512, and a touch sensor panel 6513 are fixed to the protective member 6510 by adhesive layers (not shown).

[0513] In a region outside the display portion 6502, a part of the display panel 6511 is folded back, and an FPC 6515 is connected to the folded back part. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on a printed circuit board 6517.

[0514] The light-emitting device of one embodiment of the present invention can be applied to the display panel 6511. Therefore, an extremely lightweight electronic device can be realized. Furthermore, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be mounted thereon while keeping the thickness of the electronic device small. Furthermore, by folding back a part of the display panel 6511 and arranging a connection portion with the FPC 6515 on the back side of the pixel portion, an electronic device with a narrow frame can be realized.

[0515] 21C shows an example of a television set. A television set 7100 has a display portion 7000 built into a housing 7171. Here, the housing 7171 is supported by a stand 7173.

[0516] The light-emitting device of one embodiment of the present invention can be applied to the display portion 7000. Therefore, the electronic device can have high reliability.

[0517] 21C can be operated using operation switches provided on the housing 7171 and a separate remote control 7151. Alternatively, the display portion 7000 may be provided with a touch sensor, and the television set 7100 may be operated by touching the display portion 7000 with a finger or the like. The remote control 7151 may have a display portion that displays information output from the remote control 7151. Using operation keys or a touch panel provided on the remote control 7151, the channel and volume can be controlled, and an image displayed on the display portion 7000 can be controlled.

[0518] The television device 7100 is configured to include a receiver, a modem, and the like. Ordinary television broadcasts can be received using the receiver. Furthermore, by connecting to a wired or wireless communication network via the modem, it is possible to perform one-way (from a sender to a receiver) or two-way (between a sender and a receiver, or between receivers, etc.) information communication.

[0519] 21D shows an example of a laptop personal computer 7200. The laptop personal computer 7200 includes a housing 7211, a keyboard 7212, a pointing device 7213, and an external connection port 7214. The housing 7211 includes a display portion 7000.

[0520] The light-emitting device of one embodiment of the present invention can be applied to the display portion 7000. Therefore, the electronic device can have high reliability.

[0521] 21E and 21F show an example of digital signage.

[0522] 21E includes a housing 7301, a display portion 7000, and a speaker 7303. The digital signage 7300 may further include an LED lamp, operation keys (including a power switch or an operation switch), a connection terminal, various sensors, a microphone, and the like.

[0523] 21F shows a digital signage 7400 attached to a cylindrical pillar 7401. The digital signage 7400 has a display unit 7000 provided along the curved surface of the pillar 7401.

[0524] 21E and 21F, the light-emitting device of one embodiment of the present invention can be applied to the display portion 7000. Therefore, the electronic device can have high reliability.

[0525] The larger the display unit 7000, the more information can be provided at one time. Also, the larger the display unit 7000, the more easily it will attract people's attention, which can increase the advertising effectiveness of, for example, advertisements.

[0526] Applying a touch panel to the display unit 7000 is preferable because it not only displays images or videos on the display unit 7000 but also allows the user to intuitively operate it. Furthermore, when used to provide information such as route information or traffic information, the intuitive operation can improve usability.

[0527] 21E and 21F , the digital signage 7300 or the digital signage 7400 is preferably capable of wirelessly linking with an information terminal 7311 or an information terminal 7411 such as a smartphone carried by a user. For example, advertising information displayed on the display unit 7000 can be displayed on the screen of the information terminal 7311 or the information terminal 7411. By operating the information terminal 7311 or the information terminal 7411, the display on the display unit 7000 can be switched.

[0528] Furthermore, the digital signage 7300 or the digital signage 7400 can be made to run a game using the screen of the information terminal 7311 or the information terminal 7411 as an operation means (controller), thereby allowing an unspecified number of users to simultaneously participate in and enjoy the game.

[0529] The electronic device shown in Figures 22A to 22G has a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), a connection terminal 9006, a sensor 9007 (including a function to measure force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared rays), a microphone 9008, etc.

[0530] The electronic devices shown in Figures 22A to 22G have various functions. For example, they may have a function to display various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function to display a calendar, date, time, etc., a function to control processing using various software (programs), a wireless communication function, a function to read and process programs or data recorded on a recording medium, etc. Note that the functions of the electronic devices are not limited to these, and they may have various other functions. The electronic devices may have multiple display units. Furthermore, the electronic devices may have a function to include a camera or the like to capture still images or videos and store them on a recording medium (external or built-in to the camera), a function to display the captured images on a display unit, etc.

[0531] Details of the electronic device shown in Figures 22A to 22G will be described below.

[0532] FIG. 22A is a perspective view showing a mobile information terminal 9171. The mobile information terminal 9171 can be used as, for example, a smartphone. Note that the mobile information terminal 9171 may be provided with a speaker 9003, a connection terminal 9006, a sensor 9007, or the like. The mobile information terminal 9171 can display text and image information on multiple surfaces. FIG. 22A shows an example in which three icons 9050 are displayed. Information 9051, indicated by a dashed rectangle, can also be displayed on another surface of the display unit 9001. Examples of the information 9051 include notifications of incoming emails, SNS messages, phone calls, etc., the title of the email or SNS message, the sender's name, the date and time, the remaining battery level, and radio wave intensity. Alternatively, the icon 9050 or the like may be displayed in the position where the information 9051 is displayed.

[0533] 22B is a perspective view showing a mobile information terminal 9172. The mobile information terminal 9172 has a function of displaying information on three or more sides of the display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different sides. For example, a user can check information 9053 displayed in a position that can be observed from above the mobile information terminal 9172 while storing the mobile information terminal 9172 in a breast pocket of clothes. The user can check the display without taking the mobile information terminal 9172 out of the pocket and decide, for example, whether to answer a call.

[0534] 22C is a perspective view showing a tablet terminal 9173. The tablet terminal 9173 is capable of executing various applications such as mobile phone calls, e-mail, text browsing and creation, music playback, internet communication, and computer games, for example. The tablet terminal 9173 has a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front side of a housing 9000, operation keys 9005 as operation buttons on the left side of the housing 9000, and a connection terminal 9006 on the bottom.

[0535] FIG. 22D is a perspective view showing a wristwatch-type mobile information terminal 9200. The mobile information terminal 9200 can be used as, for example, a smart watch (registered trademark). The display surface of the display unit 9001 is curved, and display can be performed along the curved display surface. The mobile information terminal 9200 can also perform hands-free calling by communicating with, for example, a headset capable of wireless communication. The mobile information terminal 9200 can also perform data transmission and charging with another information terminal through a connection terminal 9006. Note that charging may be performed by wireless power supply.

[0536] 22E to 22G are perspective views showing a foldable mobile information terminal 9201. Also, FIG. 22E is a perspective view of the mobile information terminal 9201 in an unfolded state, FIG. 22G is a perspective view of the mobile information terminal 9201 in a folded state, and FIG. 22F is a perspective view of a state in the process of changing from one of FIGS. 22E and 22G to the other. The mobile information terminal 9201 has excellent portability in a folded state, and excellent display visibility due to a seamless, wide display area in an unfolded state. A display portion 9001 of the mobile information terminal 9201 is supported by three housings 9000 connected by hinges 9055. For example, the display portion 9001 can be bent with a curvature radius of 0.1 mm or more and 150 mm or less.

[0537] This embodiment mode can be combined with other embodiment modes or examples as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0538] Example 1 In this example, physical properties and a synthesis method of an organometallic complex of one embodiment of the present invention will be described. Specifically, the organometallic complex represented by structural formula (100) in Embodiment 1 (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC]phenoxy-κC}-9-[5-(methyl-d ３ )-4-(2,6-diphenyl)phenyl-2-pyridinyl-κN]carbazole-2,1-diyl-κC)platinum(II) (abbreviation: Pt(mmtBubOcz5m4TPpy-d ３ )) will be specifically exemplified.

[0539] <Step 1: Synthesis of 2,6-diphenylphenylboronic acid> First, 5.0 g of 1-iodo-2,6-diphenylbenzene was placed in a three-neck flask and the inside was replaced with nitrogen. 60 mL of dehydrated tetrahydrofuran was added, and the flask was cooled to -78°C. 11 mL of n-butyllithium (1.6 M hexane solution) was added dropwise, and the mixture was stirred at -78°C for 2 hours. 2.4 mL of trimethyl borate was added dropwise, and the mixture was allowed to react by stirring at room temperature for 19 hours.

[0540] After a predetermined time had elapsed, 2N hydrochloric acid was added and the mixture was stirred at room temperature for 1 hour. Extraction with ethyl acetate was then performed. The resulting solid was suction filtered with toluene and washed with hexane to obtain the target product (white solid, yield: 3.0 g, 78%). The synthesis scheme of Step 1 is shown below in (a-1).

[0541]

[0542] <Step 2: Synthesis of 2-fluoro-5-methyl-4-(2,6-diphenylphenyl)pyridine> Next, 6.0 g of 2,6-diphenylphenylboronic acid obtained in Step 1 above, 4.7 g of 2-fluoro-4-iodo-5-methylpyridine, 5.5 g of sodium tert-butoxide, and 100 mL of toluene were placed in a three-necked flask equipped with a reflux condenser, and the inside of the flask was replaced with nitrogen. After degassing by stirring under reduced pressure, tris(dibenzylideneacetone)dipalladium(0) (abbreviation: Pd ２ (dba) ３ 1.5 g of 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (abbreviation: S-Phos) and 1.3 g of 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (abbreviation: S-Phos) were added, and the mixture was reacted by stirring at 130°C for 8.5 hours.

[0543] After a predetermined time had elapsed, extraction with toluene was carried out. The resulting residue was purified by silica gel column chromatography using a hexane:toluene=1:5 mixture as a developing solvent to obtain the target compound (yellow-white solid, yield: 2.9 g, 49%). The synthesis scheme of Step 2 is shown in (a-2) below.

[0544]

[0545] Step 3: Synthesis of 2-bromo-9-[5-methyl-4-(2,6-diphenylphenyl)pyridin-2-yl]carbazole Next, 3.3 g of 2-fluoro-5-methyl-4-(2,6-diphenylphenyl)pyridine obtained in Step 2 above, 2.5 g of 2-bromocarbazole, 6.3 g of cesium carbonate, and 22 mL of N-methyl-2-pyrrolidone (abbreviation: NMP) were placed in a three-neck flask equipped with a reflux condenser, and the inside was replaced with nitrogen. Thereafter, the mixture was reacted by stirring at 140° C. for 28.5 hours.

[0546] After a predetermined time had elapsed, extraction with toluene was carried out. The resulting residue was purified by silica gel column chromatography using a hexane:toluene=1:5 mixture as a developing solvent to obtain the target compound (white solid, yield: 4.7 g, 86%). The synthesis scheme of Step 3 is shown in (a-3) below.

[0547]

[0548] Step 4: 2-bromo-9-[5-(methyl-d ３ Synthesis of 2-bromo-9-[5-methyl-4-(2,6-diphenylphenyl)pyridin-2-yl]carbazole> Next, 4.7 g of 2-bromo-9-[5-methyl-4-(2,6-diphenylphenyl)pyridin-2-yl]carbazole obtained in Step 3 above, 24 mL of dimethyl sulfoxide-d6 (abbreviation: DMSO-d6), and 0.48 g of sodium tert-butoxide were placed in a recovery flask, and the inside atmosphere was replaced with nitrogen. Thereafter, the mixture was reacted by stirring at 130° C. for 1.5 hours.

[0549] After a predetermined time had elapsed, extraction with ethyl acetate was carried out. The resulting residue was purified by silica gel column chromatography using a hexane:toluene=1:5 mixture as a developing solvent to obtain the target compound (white solid, yield: 3.1 g, 66%). The synthesis scheme of Step 4 is shown in (a-4) below.

[0550]

[0551] Step 5: 2-hydroxy-9-[5-(methyl-d ３ Synthesis of 2-bromo-9-[5-(methyl-d ３ 3.1 g of [4-(2,6-diphenylphenyl)pyridin-2-yl]carbazole, 1.1 g of sodium tert-butoxide, 22 mL of dimethyl sulfoxide, and 5.4 mL of water were placed in a three-neck flask equipped with a reflux condenser, and the inside of the flask was replaced with nitrogen. After degassing by stirring under reduced pressure, 0.054 g of copper(I) chloride (abbreviation: CuCl) and 0.18 g of N1,N2-bis(4-hydroxy-2,6-dimethylphenyl)oxalamide were added, and the mixture was reacted by stirring at 110 °C for 15.5 hours.

[0552] After a predetermined time, 300 mL of water was added, and the resulting mixture was suction filtered. The resulting residue was purified by recrystallization from toluene to obtain the target compound (gray solid, yield: 2.2 g, 79%). The synthesis scheme of Step 5 is shown in (a-5) below.

[0553]

[0554] Step 6: 2-[3-(benzoimidazol-1-yl)phenoxy]-9-[5-(methyl-d ３ Synthesis of 2-hydroxy-9-[5-(methyl-d ３ 2.2 g of 1-(3-bromophenyl)benzimidazole, 1.3 g of tripotassium phosphate, and 43 mL of dimethyl sulfoxide were placed in a three-necked flask equipped with a reflux condenser, and the atmosphere was replaced with nitrogen. After degassing by stirring under reduced pressure, 0.16 g of copper(I) iodide (abbreviated as CuI) and 0.11 g of picolinic acid were added and the mixture was stirred at 160° C. for 12.5 hours to react.

[0555] After a predetermined time had elapsed, extraction with ethyl acetate was carried out. The resulting residue was purified by silica gel column chromatography using a toluene:ethyl acetate=10:1 mixture as a developing solvent to obtain the target compound (yellow-white solid, yield: 2.0 g, 67%). The synthesis scheme of Step 6 is shown in (a-6) below.

[0556]

[0557] Step 7: 1-(3,5-di-tert-butylphenyl)-3-[3-({9-[5-(methyl-d ３ Synthesis of 2-[3-(benzimidazol-1-yl)phenoxy]-9-[5-(methyl-d ３2.0 g of [2,6-diphenylphenyl)pyridin-2-yl]carbazole and 15 mL of N,N-dimethylformamide (abbreviation: DMF) were placed in a three-neck flask equipped with a reflux condenser, and the inside of the flask was purged with nitrogen. After degassing by stirring under reduced pressure, copper(II) acetate (abbreviation: Cu(OAc) ２ 0.078 g of (3,5-di-tert-butylphenyl)(mesityl)iodonium trifluoromethanesulfonate was added dropwise to the mixture, and the mixture was heated at 100° C. A solution of 3.3 g of (3,5-di-tert-butylphenyl)(mesityl)iodonium trifluoromethanesulfonate dissolved in 60 mL of DMF was added dropwise to the mixture, and the mixture was allowed to react by stirring at 100° C. for 2.5 hours.

[0558] After a predetermined time had elapsed, the solvent was distilled off, and the resulting residue was purified by silica gel column chromatography using dichloromethane:acetone=9:1 as a developing solvent to obtain the target compound (brown solid, yield: 2.6 g, 89%). The synthesis scheme of Step 7 is shown in (a-7) below.

[0559]

[0560] <Step 8: Pt(mmtBubOcz5m4TPpy-d ３ Synthesis of 1-(3,5-di-tert-butylphenyl)-3-[3-({9-[5-(methyl-d ３ 2.6 g of 2,6-diphenylphenyl)pyridin-2-yl]carbazol-2-yl}oxy)phenyl]benzimidazolium-1,1,1-trifluoromethanesulfonic acid, 1.1 g of dichloro(1,5-cyclooctadiene)platinum(II), 0.62 g of sodium acetate, and 120 mL of DMF were placed in a three-neck flask equipped with a reflux condenser, and the inside of the flask was replaced with nitrogen. Thereafter, the mixture was reacted at 160° C. for 2.5 hours with stirring.

[0561] After a predetermined time had elapsed, the solvent was distilled off, and the residue was extracted with dichloromethane. The resulting residue was purified by silica gel column chromatography using toluene as a developing solvent, and then recrystallized from toluene to obtain the target product (yellow solid, yield: 0.87 g, 32%).

[0562] 0.71 g of the obtained yellow solid was purified by train sublimation. The sublimation purification conditions were a pressure of 2.9 Pa and heating of the solid at 350°C. After sublimation purification, 0.58 g of the target yellow solid was obtained in a yield of 82%. The synthesis scheme of Step 8 is shown below in (a-8).

[0563]

[0564] <Characteristics of the organometallic complex> The yellow solid obtained in step 8 was analyzed by nuclear magnetic resonance spectroscopy ( １ The results of the analysis by H-NMR are shown below. １ 23 shows a H-NMR chart. From this, it can be seen that in this synthesis example, the organometallic complex of one embodiment of the present invention represented by the structural formula (100), Pt(mmtBubOcz5m4TPpy-d ３ ) was found to be obtained.

[0565] １ H-NMR. δ(CD ２ Cl ２ , 500MHz): 0.90 (s, 9H), 1.49 (s, 9H), 6.16 (d, 1H, J = 8.0Hz), 6.74 (d, 2H, J = 7.5Hz), 6.92 (t , 1H, J = 7.5Hz), 7.00 (t, 1H, J = 7.5Hz), 7.10-7.19 (m, 4H), 7.25-7.39 (m, 7H), 7.44 (d, 1H, J = 7.0Hz), 7.47-7.52 (m, 4H), 7.55-7.61 (m, 3H), 7.68 (d, 1H, J=7.5Hz), 7.72 (brs, 1H), 7.81 ( brs, 1H), 7.85 (d, 1H, J = 8.5Hz), 7.97 (d, 1H, J = 7.5Hz), 8.24 (d, 1H, J = 8.5Hz), 8.55 (s, 1H).

[0566] <Measurement of Emission Spectrum and Absorption Spectrum> Next, Pt(mmtBubOcz5m4TPpy-d ３The ultraviolet-visible absorption spectrum (hereinafter simply referred to as "absorption spectrum") and emission spectrum of a dichloromethane solution of 1,2-dichloro-2,4-dichloro-1,4 ...

[0567] From the results of FIG. 24, Pt(mmtBubOcz5m4TPpy-d ３ In a dichloromethane solution of 1,000 sachets ...

[0568] <Thermogravimetric measurement results> Pt (mmtBubOcz5m4TPpy-d ３ Thermogravimetry-Differential Thermal Analysis (TG-DTA) was performed on the sample. The results are shown in Fig. 25. A vacuum-controlled, high-vacuum, top-pan differential thermobalance (TG-DTA STA2500, manufactured by Netsch Japan Co., Ltd.) was used for the measurement.

[0569] The measurements were performed under two conditions. The first condition was a temperature rise rate of 10°C / min under a nitrogen flow (flow rate 100 mL / min) at a pressure equivalent to atmospheric pressure. The second condition was a temperature rise rate of 10°C / min under a nitrogen flow (flow rate 1.0 mL / min) at a pressure of 10 Pa.

[0570] As shown in FIG. 25, Pt(mmtBubOcz5m4TPpy-d ３ ) was found to have a temperature (decomposition temperature) of 481°C at which the weight determined by thermogravimetry was -5% of the weight at the start of the measurement under atmospheric pressure. On the other hand, when the measurement device was controlled at 10 Pa, it was found to have a temperature (sublimation temperature) of 322°C at which the weight determined by thermogravimetry was -5% of the weight at the start of the measurement. Therefore, the difference between the sublimation temperature and the decomposition temperature was 159°C.

[0571] That is, Pt(mmtBubOcz5m4TPpy-d ３ ) has been shown to be a highly heat-resistant material. In addition, since the difference between the sublimation temperature and the decomposition temperature is 100°C or more, when used in devices, a stable deposition process is possible in the production process. Therefore, Pt(mmtBubOcz5m4TPpy-d ３ By using the above-mentioned method, it is possible to provide devices with high yield and productivity.

[0572] In this example, the organometallic complex having a terphenyl group and an alkyl group containing deuterium, Pt(mmtBubOcz5m4TPpy-d ３ ) (100) and a light-emitting device 1 using a comparative organometallic complex, Pt(mmtBubOcz5m4ppy-d ３ ) was used to prepare a comparative light-emitting device 2 for comparison.

[0573] The structural formulae of the organic compounds used in the light-emitting device 1 and the comparative light-emitting device 2 are shown below.

[0574]

[0575] As shown in FIG. 26 , each light-emitting device has a structure in which 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 glass substrate 900, and a second electrode 902 is stacked on the electron injection layer 915.

[0576] <Method of Manufacturing Light-Emitting Device 1> A first electrode 901 was formed as a transparent electrode on a glass substrate 900 by forming a film of indium tin oxide containing silicon oxide (ITSO) to a thickness of 70 nm by sputtering. The electrode area was 4 mm ２ (2 mm x 2 mm).

[0577] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate was washed with water and baked at 200°C for 1 hour. −４The substrate was introduced into a vacuum deposition apparatus whose inside had been reduced in pressure to about Pa, and vacuum baking was carried out at 170° C. for 30 minutes in a heating chamber of the vacuum deposition apparatus, followed by natural cooling.

[0578] Next, the substrate on which the first electrode 901 was formed was fixed to a substrate holder provided in a vacuum evaporation apparatus so that the surface on which the first electrode 901 was formed faced downward. N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF) and an electron acceptor material (OCHD-003) having a molecular weight of 672 and containing fluorine were co-evaporated on the first electrode 901 in a ratio of PCBBiF:OCHD-003=1:0.03 (weight ratio) to a film thickness of 10 nm, thereby forming a hole-injection layer 911.

[0579] Next, PCBBiF was evaporated onto the hole injection layer 911 to a thickness of 30 nm, and then 9-[3-(triphenylsilyl)phenyl]-3,9′-bi-9H-carbazole (abbreviation: PSiCzCz) was evaporated to a thickness of 5 nm to form a hole transport layer 912.

[0580] Next, on the hole transport layer 912, 9,9′-{6-[3-(triphenylsilyl)phenyl]-1,3,5-triazine-2,4-diyl}bis(9H-carbazole) (abbreviation: SiTrzCz2), PSiCzCz, and Pt(mmtBubOcz5m4TPpy-d ３ ) and SiTrzCz2:PSiCzCz:Pt(mmtBubOcz5m4TPpy-d ３ ) = 0.45:0.45:0.1 (weight ratio) was co-evaporated to a thickness of 35 nm to form the light-emitting layer 913. Note that SiTrzCz2 and PSiCzCz are a combination that forms an exciplex.

[0581] Next, 2-phenyl-4,6-bis[3-(triphenylsilyl)phenyl]-1,3,5-triazine (abbreviation: mSiTrz) was evaporated on the light-emitting layer 913 to a thickness of 5 nm, and then 2,2′-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P) was evaporated on the light-emitting layer 913 to a thickness of 20 nm, thereby forming an electron-transporting layer 914.

[0582] Next, lithium fluoride (LiF) was evaporated on the electron transport layer 914 to a thickness of 1 nm to form an electron injection layer 915 .

[0583] Next, aluminum (Al) was evaporated on the electron injection layer 915 to a film thickness of 200 nm to form a second electrode 902 .

[0584] <Method of Fabricating Comparative Light-Emitting Device 2> Next, a method of fabricating comparative light-emitting device 2 for comparison will be described.

[0585] The comparative light-emitting device 2 differs from the light-emitting device 1 in the configuration of the light-emitting layer 913. That is, the comparative light-emitting device 2 is fabricated by depositing SiTrzCz2, PSiCzCz, and Pt(mmtBubOcz5m4ppy-d ３ ) and SiTrzCz2:PSiCzCz:Pt(mmtBubOcz5m4ppy-d ３ ) = 0.45:0.45:0.1 (weight ratio) was co-evaporated to a film thickness of 35 nm to form a light-emitting layer 913 .

[0586] The other components were fabricated in the same manner as the light-emitting device 1.

[0587] The device structures of the light-emitting device 1 and the comparative light-emitting device 2 are summarized in Table 1 below. In the table, X represents Pt(mmtBubOcz5m4TPpy-d ３ ) or Pt(mmtBubOcz5m4ppy-d ３ ) represents

[0588]

[0589] <Light-emitting device characteristics> Each of the above light-emitting devices was sealed with a glass substrate in a glove box with a nitrogen atmosphere so that the light-emitting device was not exposed to the atmosphere (a sealant was applied around the element, and UV treatment was performed during sealing, followed by heat treatment at 80°C for 1 hour), and then the characteristics of the light-emitting device were measured.

[0590] The luminance-current density characteristics of each light-emitting device are shown in Figure 27, the luminance-voltage characteristics in Figure 28, the current efficiency-current density characteristics in Figure 29, the current density-voltage characteristics in Figure 30, the blue index-current density characteristics in Figure 31, the external quantum efficiency-current density characteristics in Figure 32, and the electroluminescence spectrum in Figure 33.

[0591] The blue index (BI) is a value obtained by further dividing the current efficiency (cd / A) by the y value of CIE (x, y) chromaticity, and is one of the indices representing the luminous characteristics of blue light emission. The smaller the chromaticity y value, the higher the color purity of blue light emission tends to be. By using blue light emission with a small chromaticity y value and high color purity, it becomes possible to express blue colors over a wide chromaticity range on a display, and the luminance required to express white on a display is reduced, thereby achieving the effect of reducing the power consumption of the display. Therefore, the BI, which is the current efficiency taking into account the chromaticity y value, which is one index of blue purity, is preferably used as a means of representing the efficiency of blue light emission. It can be said that a light-emitting device with a higher BI has better efficiency as a blue light-emitting device used in a display.

[0592] In addition, the luminance of each light-emitting device is 1000 cd / m ２ The main characteristics of the luminance, CIE chromaticity, and electroluminescence spectrum are shown in Table 2. A spectroradiometer (SR-UL1R, manufactured by Topcon Corporation) was used to measure the luminance, CIE chromaticity, and electroluminescence spectrum. The external quantum efficiency was calculated using the luminance and electroluminescence spectrum measured using the spectroradiometer, assuming that the light distribution characteristic was Lambertian.

[0593]

[0594] 27 to 33 , it was found that the light-emitting device 1 emits blue light with high color purity and operates with a high blue index and external quantum efficiency. Furthermore, the light-emitting device 1 exhibited an electroluminescence spectrum with a peak wavelength of 471 nm and a full width at half maximum of 42 nm, while the comparative light-emitting device 2 exhibited an electroluminescence spectrum with a peak wavelength of 474 nm and a full width at half maximum of 52 nm. The light-emitting device 1 exhibited a short wavelength and a sharp emission spectrum. Therefore, it was confirmed that by using an organometallic complex of platinum (Pt) having a terphenyl group and an alkyl group containing deuterium, which is one embodiment of the present invention, in a light-emitting device, it is possible to provide a light-emitting device with a short wavelength and narrow linewidth of electroluminescence spectrum and high efficiency.

[0595] Here, Pt(mmtBubOcz5m4TPpy-d ３ The HOMO and LUMO levels of the compound (II) were calculated by cyclic voltammetry (CV) measurement using an electrochemical analyzer (manufactured by BAS Inc., model number: ALS Model 600A or 600C).

[0596] Pt(mmtBubOcz5m4TPpy-d ３ The solution used dehydrated dimethylformamide (DMF) as a solvent. The potential of the working electrode relative to the reference electrode was varied within an appropriate range to obtain the oxidation and reduction peak potentials. A platinum electrode (PTE platinum electrode, manufactured by BAS Co., Ltd.) was used as the working electrode, a platinum electrode (Pt counter electrode (5 cm) for VC-3, manufactured by BAS Co., Ltd.) was used as the auxiliary electrode, and an Ag / Ag+ electrode (RE7 nonaqueous solvent reference electrode, manufactured by BAS Co., Ltd.) was used as the reference electrode.

[0597] In addition, since the redox potential of the reference electrode was estimated to be −4.94 eV, the HOMO level and LUMO level of the compound were calculated from this value and the obtained peak potential. ３ The HOMO level of Pt(mmtBubOcz5m4TPpy-d) was −5.48 eV and the LUMO level was −2.47 eV. ３) has a low HOMO level and is unlikely to form an exciplex with the host.

[0598] From the above, it was found that the light emitting device 1 is a light emitting device that exhibits good characteristics.

[0599] In this example, the organometallic complex is partially different from that in Example 1 and is represented by the following structural formula (122).

[0600]

[0601] The organometallic complex of the present invention represented by the above structural formula (122) is (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-[5-(methyl-d ３ )-4-(3,5-dimethyl-2,6-diphenyl)phenyl-2-pyridinyl-κN]carbazole-2,1-diyl-κC)platinum(II) (abbreviation: [Pt(mmtBubOcz5m4dmTPpy-d ３ ) )]) is shown below.

[0602] <Step 1: Synthesis of 1-iodo-3,5-dimethyl-2,6-diphenylbenzene>

[0603] First, 1.0 g of 1,5-dichloro-2,4-dimethylbenzene was placed in a three-neck flask and the inside atmosphere was replaced with nitrogen. 34 mL of dehydrated tetrahydrofuran (abbreviated as THF) was added, and the flask was cooled to -78°C. 3.9 mL of n-butyllithium (1.6 M hexane solution) was added dropwise, and the mixture was stirred at -78°C for 2 hours. 14 mL of phenylmagnesium bromide (1.0 M THF solution) was added dropwise, and the mixture was stirred at room temperature for 16 hours. The mixture was then stirred at 80°C for 3.5 hours. After cooling the flask to 0°C, a solution of 2.2 g of iodine dissolved in 20 mL of THF was added dropwise, and the mixture was allowed to react by stirring at room temperature for 24 hours.

[0604] After a predetermined time, 50 mL of sodium thiosulfate solution was added, and extraction with ethyl acetate was performed. The obtained solid was dissolved in toluene and filtered through a filter aid layered in the order of Celite, alumina, and Celite. The filtrate was concentrated to obtain the target product (white solid, yield 1.7 g, yield 77%). The synthesis scheme of step 1 is shown below in (b-1).

[0605]

[0606] <Step 2: Synthesis of 3,5-dimethyl-2,6-diphenylphenylboronic acid>

[0607] Next, 3.6 g of 1-iodo-3,5-dimethyl-2,6-diphenylbenzene obtained in Step 1 above was placed in a three-neck flask, and the inside of the flask was replaced with nitrogen. 117 mL of dehydrated tetrahydrofuran was added, and the flask was cooled to -78°C. 7.0 mL of n-butyllithium (1.6 M hexane solution) was added dropwise, and the mixture was stirred at -78°C for 2 hours. 1.6 mL of trimethyl borate was added dropwise, and the mixture was allowed to react by stirring at room temperature for 17 hours.

[0608] After a predetermined time had elapsed, 50 mL of 2N hydrochloric acid was added and the mixture was stirred at room temperature for 1 hour. Extraction with ethyl acetate was then performed. The resulting solid was suction filtered with toluene and washed with hexane to obtain the target product (white solid, yield: 2.0 g, 70%). The synthesis scheme for Step 2 is shown in (a-2) below.

[0609]

[0610] <Step 3: Synthesis of 2-fluoro-5-methyl-4-(3,5-dimethyl-2,6-diphenylphenyl)pyridine>

[0611] Next, 2.0 g of 3,5-dimethyl-2,6-diphenylphenylboronic acid obtained in Step 2 above, 1.4 g of 2-fluoro-4-iodo-5-methylpyridine, 1.1 g of sodium tert-butoxide, and 30 mL of toluene were placed in a three-necked flask equipped with a reflux condenser, and the inside of the flask was replaced with nitrogen. After degassing by stirring under reduced pressure, tris(dibenzylideneacetone)dipalladium(0) (abbreviation: Pd ２ (dba)３ ) and 0.39 g of 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (abbreviation: S-Phos) were added, and the mixture was reacted by stirring at 130°C for 7.5 hours.

[0612] After a predetermined time had elapsed, extraction with toluene was carried out. The resulting residue was purified by silica gel column chromatography using a hexane:toluene=1:5 mixture as a developing solvent to obtain the target compound (yellow-white solid, yield: 1.3 g, 60%). The synthesis scheme of Step 3 is shown in (b-3) below.

[0613]

[0614] <Step 4: Synthesis of 2-bromo-9-[5-methyl-4-(3,5-dimethyl-2,6-diphenylphenyl)pyridin-2-yl]carbazole>

[0615] Next, 1.3 g of 2-fluoro-5-methyl-4-(3,5-dimethyl-2,6-diphenylphenyl)pyridine obtained in Step 3 above, 0.92 g of 2-bromocarbazole, 2.3 g of cesium carbonate, and 10 mL of N-methyl-2-pyrrolidone (abbreviation: NMP) were placed in a three-neck flask equipped with a reflux condenser, and the inside of the flask was replaced with nitrogen. Thereafter, the mixture was reacted by stirring at 140° C. for 34.5 hours.

[0616] After a predetermined time had elapsed, 30 mL of water was added, and the precipitated solid was filtered under suction. The resulting solid was purified by silica gel column chromatography using dichloromethane as a developing solvent to obtain the target compound (white solid, yield: 1.4 g, 67%). The synthesis scheme of Step 4 is shown in (b-4) below.

[0617]

[0618] Step 5: 2-bromo-9-[5-(methyl-d ３ Synthesis of [3,5-dimethyl-2,6-diphenylphenyl]pyridin-2-yl]carbazole

[0619] Next, 1.4 g of 2-bromo-9-[5-methyl-4-(3,5-dimethyl-2,6-diphenylphenyl)pyridin-2-yl]carbazole obtained in Step 4 above, 12 mL of dimethyl sulfoxide-d6 (abbreviation: DMSO-d6), and 0.14 g of sodium tert-butoxide were placed in a recovery flask, and the inside of the flask was replaced with nitrogen. Thereafter, the mixture was reacted by stirring at 120° C. for 3 hours.

[0620] After a predetermined time had elapsed, extraction with ethyl acetate was carried out. The resulting residue was purified by silica gel column chromatography using a hexane:toluene=1:3 mixture as a developing solvent to obtain the target compound (white solid, yield: 1.1 g, 78%). The synthesis scheme of Step 5 is shown in (b-5) below.

[0621]

[0622] Step 6: Synthesis of 1-(3-methoxyphenyl)benzimidazole

[0623] Next, 3.5 g of benzimidazole, 7.2 mL of 1-iodo-3-methoxybenzene, 8.3 g of potassium carbonate, and 150 mL of dimethyl sulfoxide (DMSO) were placed in a three-necked flask equipped with a reflux condenser, and the inside of the flask was replaced with nitrogen. After degassing by stirring under reduced pressure, 1.1 g of copper iodide and 1.4 g of L-proline were added and reacted by stirring at 100° C. for 22.5 hours.

[0624] After a predetermined time had passed, extraction with ethyl acetate was carried out. The resulting residue was purified by silica gel column chromatography using a 2:1 mixture of hexane and ethyl acetate as a developing solvent to obtain the target compound (yellow-brown oil, yield: 5.1 g, 75%). The synthesis scheme of Step 6 is shown in (b-6) below.

[0625]

[0626] Step 7: Synthesis of 1-(3-hydroxyphenyl)benzimidazole

[0627] Next, 5.1 g of 1-(3-methoxyphenyl)benzimidazole obtained in Step 6 above, 180 mL of hydrochloric acid, and 45 mL of acetic acid were placed in a three-necked flask equipped with a reflux condenser, and the inside of the flask was replaced with nitrogen. Thereafter, the mixture was reacted by stirring at 120° C. for 21 hours.

[0628] After a predetermined time had elapsed, the solvent was distilled off. A saturated aqueous solution of sodium bicarbonate was added to the resulting residue to neutralize it. Extraction with ethyl acetate was then performed. The resulting residue was purified by silica gel column chromatography using a 2:1 mixture of hexane and ethyl acetate as a developing solvent to obtain the target compound (yellow-white solid, yield: 1.8 g, 38%). The synthesis scheme for Step 7 is shown in (b-7) below.

[0629]

[0630] Step 8: 2-[3-(benzoimidazol-1-yl)phenoxy]-9-[5-(methyl-d ３ Synthesis of [3,5-dimethyl-2,6-diphenylphenyl]pyridin-2-yl]carbazole

[0631] Next, 2-bromo-9-[5-(methyl-d ３ 0.95 g of 1-(3-hydroxyphenyl)benzimidazole (obtained in Step 7), 0.3 g of tripotassium phosphate (potassium phosphate), and 15 mL of dimethyl sulfoxide were placed in a three-neck flask equipped with a reflux condenser, and the atmosphere was replaced with nitrogen. After the contents of the flask were degassed by stirring under reduced pressure, 0.054 g of copper(I) iodide (abbreviation: CuI) and 0.036 g of picolinic acid were added, and the mixture was stirred at 160° C. for 16 hours to react the mixture.

[0632] After a predetermined time had elapsed, extraction with ethyl acetate was carried out. The resulting residue was purified by silica gel column chromatography using a 2:1 mixture of toluene and ethyl acetate as a developing solvent to obtain the target compound (brown oil, yield: 0.85 g, 82%). The synthesis scheme of Step 8 is shown in (b-8) below.

[0633]

[0634] Step 9: 1-(3,5-di-tert-butylphenyl)-3-[3-({9-[5-(methyl-d ３ Synthesis of]-4-(3,5-dimethyl-2,6-diphenylphenyl)pyridin-2-yl]carbazol-2-yl}oxy)phenyl]benzimidazolium-1,1,1-trifluoromethanesulfonic acid

[0635] Next, 2-[3-(benzoimidazol-1-yl)phenoxy]-9-[5-(methyl-d ３ 0.85 g of [N,N-dimethylformamide (abbreviation: DMF)]-4-(3,5-dimethyl-2,6-diphenylphenyl)pyridin-2-yl]carbazole and 12 mL of N,N-dimethylformamide (abbreviation: DMF) were placed in a three-neck flask equipped with a reflux condenser, and the inside of the flask was purged with nitrogen. After degassing by stirring under reduced pressure, copper(II) acetate (abbreviation: Cu(OAc) ２ 0.033 g of (3,5-di-tert-butylphenyl)(mesityl)iodonium trifluoromethanesulfonate was added dropwise to the mixture, and the mixture was heated at 100° C. A solution of 1.4 g of (3,5-di-tert-butylphenyl)(mesityl)iodonium trifluoromethanesulfonate dissolved in 22 mL of DMF was added dropwise to the mixture, and the mixture was stirred at 100° C. for 1.5 hours to allow the reaction to proceed.

[0636] After a predetermined time had elapsed, the solvent was distilled off, and the resulting residue was purified by silica gel column chromatography using dichloromethane:acetone=9:1 as a developing solvent to obtain the target compound (brown oil, yield 1.2 g, 96%). The synthesis scheme of Step 9 is shown in (b-9) below.

[0637]

[0638] Step 10: (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-[5-(methyl- ３ )-4-(3,5-dimethyl-2,6-diphenyl)phenyl-2-pyridinyl-κN]carbazole-2,1-diyl-κC)platinum(II) (abbreviation: [Pt(mmtBubOcz5m4TPpy-d ３ Synthesis of

[0639] Next, the 1-(3,5-di-tert-butylphenyl)-3-[3-({9-[5-(methyl-d ３ 1.2 g of 4-(3,5-dimethyl-2,6-diphenylphenyl)pyridin-2-yl]carbazol-2-yl}oxy)phenyl]benzimidazolium-1,1,1-trifluoromethanesulfonic acid, 0.53 g of dichloro(1,5-cyclooctadiene)platinum(II), 0.29 g of sodium acetate, and 53 mL of DMF were placed in a three-neck flask equipped with a reflux condenser, and the inside atmosphere was replaced with nitrogen. Thereafter, the mixture was reacted at 160° C. for 5.5 hours with stirring.

[0640] After a predetermined time had elapsed, the solvent was distilled off, and the mixture was extracted with dichloromethane. The resulting residue was purified by silica gel column chromatography using toluene as a developing solvent, and then recrystallized from a mixed solvent of toluene and ethanol to obtain the target product (yellow solid, yield: 0.53 g, 42%).

[0641] 0.53 g of the obtained yellow solid was purified by train sublimation. The sublimation purification conditions were a pressure of 2.6 Pa and heating of the solid at 340°C. After sublimation purification, 0.37 g of the target yellow solid was obtained in a yield of 70%. The synthesis scheme of Step 10 is shown below in (b-10).

[0642]

[0643] <Characteristics of the organometallic complex> The yellow solid obtained in step 10 was analyzed by nuclear magnetic resonance spectroscopy ( １ The results of the analysis by H-NMR are shown below. １ 34 shows a H-NMR chart. From this, it can be seen that in this synthesis example, the organometallic complex of one embodiment of the present invention, Pt(mmtBubOcz5m4dmTPpy-d ３ ) was found to be obtained.

[0644] １ H-NMR. δ(CD ２ Cl ２, 500MHz): 0.81 (s, 9H), 1.52 (s, 9H), 1.96 (s, 3H), 2.07 (s, 3H), 6.14 (d, 1H, J=7. 0Hz), 6.54 (t, 1H, J=7.5Hz), 6.83 (br, 1H), 6.89 (br, 1H), 6.96-6.98 (m, 1H), 7.06 -7.10 (m, 3H), 7.22 (s, 1H), 7.30-7.39 (m, 7H), 7.45-7.55 (m, 5H), 7.66-7.74 (m, 4H) H), 7.86 (d, 1H, J = 8.0Hz), 8.00-8.02 (m, 1H), 8.23 ​​(d, 1H, J = 8.5Hz), 8.32 (s, 1H).

[0645] <Measurement of Emission Spectrum and Absorption Spectrum> Next, Pt(mmtBubOcz5m4dmTPpy-d ３ The ultraviolet-visible absorption spectrum (hereinafter simply referred to as "absorption spectrum") and emission spectrum of a dichloromethane solution of 1,2-dichloro-2,4-dichloro-1,4-dichloro-2,4-dione were measured. The absorption spectrum was measured using an ultraviolet-visible spectrophotometer (V550 model, manufactured by JASCO Corporation). The emission spectrum was measured using a spectrofluorometer (FP-8600, manufactured by JASCO Corporation). The measurement results of the absorption spectrum and emission spectrum of the obtained dichloromethane solution are shown in Figure 35. The horizontal axis represents wavelength, and the vertical axis represents absorption intensity and emission intensity.

[0646] From the results of Figure 35, Pt(mmtBubOcz5m4dmTPpy-d ３ In a dichloromethane solution of 1,000 sachets ...

[0647] <Thermogravimetric measurement results> Pt (mmtBubOcz5m4dmTPpy-d ３ Thermogravimetry-Differential Thermal Analysis (TG-DTA) was performed on the sample. The results are shown in Figure 36. A vacuum-controlled, high-vacuum, top-pan differential thermobalance (TG-DTA STA2500, manufactured by Netsch Japan Co., Ltd.) was used for the measurement.

[0648] The measurements were performed under two conditions. The first condition was a temperature rise rate of 10°C / min under a nitrogen flow (flow rate 100 mL / min) at a pressure equivalent to atmospheric pressure. The second condition was a temperature rise rate of 10°C / min under a nitrogen flow (flow rate 1.0 mL / min) at a pressure of 10 Pa.

[0649] As shown in FIG. 36, Pt(mmtBubOcz5m4dmTPpy-d ３ ) was found to have a temperature (decomposition temperature) of 471°C at which the weight determined by thermogravimetry was -5% of the weight at the start of the measurement under atmospheric pressure. On the other hand, when the measurement device was controlled at 10 Pa, it was found to have a temperature (sublimation temperature) of 310°C at which the weight determined by thermogravimetry was -5% of the weight at the start of the ...

Claims

An organometallic complex represented by General Formula (G1): (In the formula, R １ , R ２ , and R ４ ~R ３１ each independently represents hydrogen (including deuterium), an alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, and R ２ or R ４ At least one of R represents an alkyl group having 1 to 10 carbon atoms; １８ ~R ２２ represents an alkyl group having 3 to 10 carbon atoms or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms; R ２３ represents the following general formula (R-1): (In the formula, R ３２ ~R ３６ each independently represents hydrogen (including deuterium), an alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms. An organometallic complex represented by structural formula (100): 　 A light-emitting device comprising the organometallic complex of claim 1 or claim 2.

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