Light-receiving device, light emission / reception apparatus, and electronic equipment

Abstract

The present invention provides a novel light-receiving device. Provided is a light-receiving device having a light receiving layer between a pair of electrodes. The light receiving layer has an active layer, and the active layer has a first organic compound and a second organic compound. The absorption spectrum of the first organic compound has one or more peaks, and the wavelength of at least one of the peaks is 400-700 nm. The HOMO level of the second organic compound is higher than the HOMO level of the first organic compound. The difference between the HOMO level of the first organic compound and the HOMO level of the second organic compound is preferably 0.2-1.5 eV, and more preferably 0.4-1.5 eV.

Description

Light receiving devices, light emitting and receiving devices, electronic devices

[0001] One embodiment of the present invention relates to a light-receiving device, a light-emitting and receiving device, an electronic device, or a semiconductor device.

[0002] 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 light-emitting device, a power storage device, a memory device, a driving method thereof, or a manufacturing method thereof.

[0003] A functional panel is known in which pixels provided in a display area include a light-emitting element and a photoelectric conversion element (see Patent Document 1). For example, a functional panel includes a first drive circuit, a second drive circuit, and an area, where the first drive circuit supplies a first selection signal, and the second drive circuit supplies a second selection signal and a third selection signal. The area includes pixels. The pixels include a first pixel circuit, a light-emitting element, a second pixel circuit, and a photoelectric conversion element. The first pixel circuit is supplied with the first selection signal, and acquires an image signal based on the first selection signal. The light-emitting element is electrically connected to the first pixel circuit, and the light-emitting element emits light based on the image signal. The second pixel circuit is supplied with a second selection signal and a third selection signal during a period when the first selection signal is not supplied, and acquires an imaging signal based on the second selection signal and supplies the imaging signal based on the third selection signal. The photoelectric conversion element is electrically connected to the second pixel circuit, and the photoelectric conversion element generates an imaging signal.

[0004] WO2020 / 152556

[0005] An object of one embodiment of the present invention is to provide a novel light-receiving device, a novel light-receiving and light-emitting device, or a novel electronic device.

[0006] 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.

[0007] One embodiment of the present invention is a light-receiving device including a light-receiving layer between a pair of electrodes, the light-receiving layer including an active layer, the active layer including a first organic compound and a second organic compound, an absorption spectrum of the first organic compound having one or more peaks, at least one of the peaks having a peak wavelength of 400 nm to 700 nm, and a HOMO level of the second organic compound being higher than a HOMO level of the first organic compound.

[0008] In the light-receiving device having the above structure, it is preferable that the difference between the HOMO level of the first organic compound and the HOMO level of the second organic compound is 0.2 eV or more and 1.5 eV or less.

[0009] In the light-receiving device having the above structure, the difference between the HOMO level of the first organic compound and the HOMO level of the second organic compound is preferably 0.4 eV or more and 1.5 eV or less.

[0010] In the light-receiving device having each of the above configurations, the LUMO level of the first organic compound is preferably −3.5 eV or more and −2.5 eV or less.

[0011] In the light-receiving device having each of the above configurations, the second organic compound may have an absorption spectrum with a maximum peak wavelength of 400 nm or less.

[0012] In the light-receiving device having each of the above configurations, the first organic compound is preferably a polyacene derivative.

[0013] In the light-receiving device having each of the above configurations, the second organic compound preferably has a hole transporting property higher than an electron transporting property.

[0014] In the light-receiving device having each of the above configurations, the second organic compound is preferably a compound having a π-electron rich heteroaromatic ring or an aromatic amine.

[0015] Another embodiment of the present invention is a light-receiving and light-emitting device including a light-receiving device having any of the above structures and a light-emitting device.

[0016] Another embodiment of the present invention is an electronic device including the light-emitting and receiving device having the above structure and a detection unit, an input unit, or a communication unit.

[0017] In the drawings accompanying this specification, components are classified by function and shown as independent blocks in block diagrams, but in reality, it is difficult to completely separate components by function, and one component may be involved in multiple functions.

[0018] According to one embodiment of the present invention, a novel light-receiving device, a novel light-receiving and light-emitting device, or a novel and excellent electronic device can be provided.

[0019] 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.

[0020] FIGS. 1A to 1C are diagrams illustrating a light-receiving device according to one embodiment of the present invention. FIGS. 2A to 2C are energy diagrams illustrating a light-receiving device according to one embodiment of the present invention. FIGS. 3A to 3C are diagrams illustrating an optical receiver / emitting device according to one embodiment of the present invention. FIGS. 4A and 4B are diagrams illustrating an optical receiver / emitting device according to one embodiment of the present invention. FIGS. 5A to 5E are diagrams illustrating a configuration of a light-emitting device according to an embodiment. FIGS. 6A to 6D are diagrams illustrating an optical receiver / emitting device according to an embodiment. FIGS. 7A to 7C are diagrams illustrating a method for manufacturing an optical receiver / emitting device according to an embodiment. FIGS. 8A to 8C are diagrams illustrating a method for manufacturing an optical receiver / emitting device according to an embodiment. FIGS. 9A to 9C are diagrams illustrating a method for manufacturing an optical receiver / emitting device according to an embodiment. FIGS. 10A to 10D are diagrams illustrating a method for manufacturing an optical receiver / emitting device according to an embodiment. FIGS. 11A to 11E are diagrams illustrating a method for manufacturing an optical receiver / emitting device according to an embodiment. FIGS. 12A to 12F are diagrams illustrating a device and pixel arrangement according to an embodiment. FIGS. 13A to 13C are diagrams illustrating a pixel circuit according to an embodiment. FIG. 14 is a diagram illustrating a light-emitting device according to an embodiment. FIGS. 15A to 15E are diagrams illustrating an electronic device according to an embodiment. FIGS. 16A to 16E are diagrams illustrating an electronic device according to an embodiment. FIGS. 17A and 17B are diagrams illustrating an electronic device according to an embodiment. FIG. 18 is a diagram illustrating a light-receiving device according to one aspect of the present invention. FIG. 19 is absorption spectra of Rubrene, m-MTDATA, and DNTPD. FIG. 20 is absorption spectra of PCBBiF and BBABnf. FIG. 21 is a diagram illustrating the HOMO levels and LUMO levels of Rubrene, m-MTDATA, DNTPD, PCBBiF, and BBABnf. FIG. 22 is a diagram illustrating current-voltage characteristics of a light-receiving device. FIG. 23 is a diagram illustrating current-voltage characteristics of a light-receiving device. FIG. 24 is a diagram illustrating the external quantum efficiency of a light-receiving device.

[0021] The embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be readily understood by those skilled in the art that various changes in form and details can be made without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the embodiments shown below. In the configuration of the invention described below, the same parts or parts having similar functions will be denoted by the same reference numerals in different drawings, and repeated explanations will be omitted.

[0022] Embodiment 1 In this embodiment, a light-receiving device according to one embodiment of the present invention will be described.

[0023] A light-receiving device according to one embodiment of the present invention has a function of detecting light (hereinafter also referred to as a light-receiving function).

[0024] FIG. 1 shows a schematic cross-sectional view of a light-receiving device 200 according to one embodiment of the present invention.

[0025] The basic structure of a light-receiving device will be described. Fig. 1A shows a light-receiving device 200 having a light-receiving layer 203 including at least an active layer and a carrier transport layer between a pair of electrodes. Specifically, the light-receiving layer 203 is sandwiched between a first electrode 101 and a second electrode 202.

[0026] 1B shows a layered structure of an absorption layer 203 of a light-receiving device 200 according to one embodiment of the present invention. The absorption layer 203 has a structure in which a first carrier transport layer 212, an active layer 213, and a second carrier transport layer 214 are sequentially stacked on a first electrode 201.

[0027] 1C shows the layered structure of light-receiving layer 203 of light-receiving device 200 according to one embodiment of the present invention. Light-receiving layer 203 has a structure in which first carrier injection layer 211, first carrier transport layer 212, active layer 213, second carrier transport layer 214, and second carrier injection layer 215 are sequentially layered on first electrode 201.

[0028] In addition, in the absorption layer 203 having the structure shown in FIGS. 1B and 1C, a buffer layer may be provided between the active layer 213 and the second carrier transport layer 214.

[0029] Next, a specific structure of the active layer 213 included in the light-receiving device 200 of one embodiment of the present invention will be described.

[0030] <Active Layer> The active layer 213 is a layer that generates carriers based on incident light, and includes at least a first organic compound and a second organic compound.

[0031] The first organic compound may be an organic compound whose absorption spectrum has one or more peaks, at least one of which has a peak wavelength of 400 nm or more and 700 nm or less. In other words, the first organic compound may be an organic compound that absorbs visible light.

[0032] The second organic compound may be an organic compound whose HOMO (Highest Occupied Molecular Orbital) level is higher than the HOMO level of the first organic compound.

[0033] An energy diagram when a light-receiving device 200 having the above-described first organic compound and second organic compound in the active layer 213 receives light will be described with reference to FIG. 2 . Note that here, the first electrode 201 functions as an anode, and the second electrode 202 functions as a cathode. Furthermore, a first carrier transport layer 212 and a second carrier transport layer 214 are adjacent to the active layer 213. Furthermore, the active layer 213 includes the above-described first organic compound 213_1 and second organic compound 213_2, the first carrier transport layer 212 includes a hole transport material 212_1, and the second carrier transport layer 214 includes an electron transport material 214_1.

[0034] First, when the light-receiving device 200 receives visible light, electrons are excited from the HOMO of the first organic compound 213_1 in the active layer 213 to the LUMO (Lowest Unoccupied Molecular Orbital) (see FIG. 2A), and holes are generated in the HOMO.

[0035] Next, a hole moves from the HOMO of the first organic compound 213_1 to the HOMO of the second organic compound 213_2, which has higher energy (see FIG. 2B), and an electron moves from the HOMO of the second organic compound 213_2 to the HOMO of the first organic compound 213_1.

[0036] Next, holes are injected from the active layer 213 into the first carrier transport layer 212, and electrons are injected into the second carrier transport layer 214. Specifically, holes move from the HOMO of the second organic compound 213_2 to the HOMO of the hole transport material 212_1, and electrons move from the LUMO of the first organic compound 213_1 to the LUMO of the electron transport material 214_1 (see FIG. 2C ).

[0037] In this way, when the active layer 213 receives visible light, carriers are generated and a current flows in the light-receiving device 200, so that the light can be detected.

[0038] As described above, in the operation of the light-receiving device 200, holes need to move from the HOMO of the first organic compound 213_1 to the HOMO of the second organic compound 213_2. Therefore, the HOMO level of the second organic compound 213_2 is configured to be higher than the HOMO level of the first organic compound 213_1.

[0039] The difference between the HOMO level of the first organic compound 213_1 and the HOMO level of the second organic compound 213_2 is preferably 0.2 eV to 1.5 eV, more preferably 0.4 eV to 1.5 eV, which can increase the efficiency of hole transfer from the HOMO of the first organic compound 213_1 to the HOMO of the second organic compound 213_2.

[0040] The LUMO level of the first organic compound 213_1 is preferably greater than or equal to −3.5 eV and less than or equal to −2.5 eV, which can increase the efficiency of electron transfer from the LUMO of the first organic compound 213_1 to the LUMO of the electron-transporting material 214_1.

[0041] As described above, the absorption spectrum of the first organic compound 213_1 has one or more peaks, and at least one of the peaks has a peak wavelength of 400 nm or more and 700 nm or less. This allows the light-receiving device 200 to respond to visible light even if the absorption spectrum of the second organic compound 213_2 does not have a peak wavelength in the range of 400 nm or more and 700 nm or less. In other words, the maximum peak wavelength of the absorption spectrum of the second organic compound may be 400 nm or less. In this way, even if the second organic compound is a material that does not easily absorb visible light, the light-receiving device 200 can respond to visible light.

[0042] Next, specific examples of the first organic compound and the second organic compound that satisfy the above requirements will be described.

[0043] Specific examples of the first organic compound include organic semiconductor materials such as copper(II) phthalocyanine (CuPc), tetraphenyldibenzoperiflanthene (DBP), zinc phthalocyanine (ZnPc), tin phthalocyanine (SnPc), and quinacridone.

[0044] Specific examples of the first organic compound include carbazole derivatives, thiophene derivatives, furan derivatives, compounds having an aromatic amine skeleton, etc. Specific examples of the first organic compound include naphthalene derivatives, pyrene derivatives, triphenylene derivatives, fluorene derivatives, pyrrole derivatives, benzofuran derivatives, benzothiophene derivatives, indole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, indolocarbazole derivatives, porphyrin derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, quinacridone derivatives, polyphenylenevinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, polythiophene derivatives, etc.

[0045] Furthermore, a polyacene derivative can be used as the first organic compound. A polyacene derivative has a high electron-transporting property, and therefore can further increase the efficiency of electron transfer from the LUMO of the first organic compound to the LUMO of the electron-transporting material 214_1, which is preferable.

[0046] As the first organic compound, an organic compound represented by the following general formula (Ga-1) can be used.

[0047]

[0048] In the above general formula (Ga-1), R ２１ ~R ３０ each independently represents hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 13 carbon atoms, a cycloalkyl group having 3 to 13 carbon atoms, halogen, a substituted or unsubstituted halogenated alkyl group having 1 to 13 carbon atoms, a cyano group, a substituted or unsubstituted alkoxy group having 1 to 13 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms; and m represents an integer of 1 to 5.

[0049] In the above general formula (Ga-1), R ２１ ~R ３０ are each preferably independently any one of the substituents represented by the following formulae (Ra-1) to (Ra-77): In the formula, * represents a bond.

[0050]

[0051]

[0052]

[0053] Next, specific examples of the first organic compound represented by the above general formula (Ga-1) are shown below.

[0054]

[0055]

[0056] The organic compounds represented by the structural formulas (100) to (116) are examples of the organic compounds represented by the general formula (Ga-1), but specific examples of the first organic compound are not limited to these.

[0057] The second organic compound is 10 −６ cm ２ A substance having a hole mobility of 1 / Vs or more is preferred. Note that other substances can also be used as long as they have a higher hole transporting property than electron transporting property.

[0058] Furthermore, as the second organic compound, a material with high hole transport properties, such as a compound having a π-electron-rich heteroaromatic ring (e.g., a carbazole derivative, a furan derivative, a thiophene derivative, or the like) or an aromatic amine (an organic compound having an aromatic amine skeleton), can be used.

[0059] Examples of the carbazole derivatives (organic compounds having a carbazole ring) include bicarbazole derivatives (for example, 3,3'-bicarbazole derivatives), aromatic amines having a carbazolyl group, and the like.

[0060] Specific examples of the bicarbazole derivatives (e.g., 3,3′-bicarbazole derivatives) include 3,3′-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), 9,9′-bis(biphenyl-4-yl)-3,3′-bi-9H-carbazole (abbreviation: BisBPCz), 9,9′-bis(1,1′-biphenyl-3-yl)-3,3′-bi-9H-carbazole (abbreviation: BismBPCz), 9-(1,1′-biphenyl-3-yl)-9′-(1,1′-biphenyl-4-yl)-9H,9′H-3,3′-bicarbazole (abbreviation: mBPCCBP), and 9-(2-naphthyl)-9′-phenyl-9H,9′H-3,3′-bicarbazole (abbreviation: βNCCP).

[0061] Specific examples of the aromatic amine having a carbazolyl group include 4-phenyl-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazol-3-amine (abbreviation: PCBiF), N-(1,1′-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)]- ...triphenylamine (abbreviation: PCBiF), N-(1,1′-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)]-triphenylamine (abbreviation: PCBA1BP), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-triphenylamine (abbreviation: PCBiF), N-(1,1′-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)]-triphenylamine (abbreviation: PCBA1BP), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-triphenylamine (abbreviation: PCBA1BP), N-(4-biphenyl)-N-(9,9 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: PCBBiF), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4,4'-di(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: PCBBiF), 4,4'-diphenyl ... N,N'-bis(9-phenylcarbazol-3-yl)-N,N'-diphenylbenzene-1,3-diamine (abbreviation: PCA2B), N,N',N''-triphenyl-N,N',N''-tris(9-phenylcarbazol-3-yl)benzene-1,3,5-triamine (abbreviation: PCA3B), 9-phenyldiphenylamine (abbreviation: PCBNBB), 4-phenyldiphenyl-(9-phenyl-9H-carbazol-3-yl)amine (abbreviation: PCA1BP), ... ,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]spiro-9,9′-bifluoren-2-amine (abbreviation: PCBASF), 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), 3-[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA1), 3,6-bis[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA2), 3,6-bis[N-(4-diphenylaminophenyl)-N-(1 -naphthyl)amino]-9-phenylcarbazole (abbreviation: PCzTPN2), 2-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: PCASF), N-[4-(9H-carbazol-9-yl)phenyl]-N-(4-phenyl)phenylaniline (abbreviation: YGA1BP), N,N'-bis[4-(carbazol-9-yl)phenyl]-N,N'-diphenyl-9,9-dimethylfluorene-2,7-diamine (abbreviation: YGA2F), 4,4',4''-tris(carbazol-9-yl)triphenylamine (abbreviation: TCTA), and the like.

[0062] In addition to the above, examples of the carbazole derivatives include 3-[4-(9-phenanthryl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPPn), 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4′-di(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviation: TCPB), and 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA).

[0063] Specific examples of the furan derivatives (organic compounds having a furan ring) include 4,4′,4″-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II).

[0064] Specific examples of the thiophene derivative (organic compound having a thiophene ring) include organic compounds having a thiophene ring, such as 4,4′,4″-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV).

[0065] Specific examples of the aromatic amine include 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB or α-NPD), N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1′-biphenyl]-4,4′-diamine (abbreviation: TPD), 4,4′-bis[N-(spiro-9,9′-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP ... N-(4-biphenyl)-N-{4-[(9-phenyl)-9H-fluoren-9-yl]-phenyl}-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: FBiFLP), N,N,N',N'-tetrakis(4-biphenyl)-1,1-biphenyl-4,4'-diamine (abbreviation: BBA2BP), N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: SF ４FAF), N-(9,9-dimethyl-9H-fluoren-2-yl)-N-{9,9-dimethyl-2-[N'-phenyl-N'-(9,9-dimethyl-9H-fluoren-2-yl)amino]-9H-fluoren-7-yl}phenylamine (abbreviation: DFLADFL), N-(9,9-dimethyl-2-diphenylamino-9H-fluoren-7-yl)diphenylamine (abbreviation: DPNF), 2-[N-(4-diphenylaminophenyl)-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: DPASF), 2,7-bis[N-(4-diphenylaminophenyl)-N-phenylamino]spiro-9,9'-bifluorene [N-(3-methylphenyl)-N-phenylaminophenyl]-spiro-9,9'-bifluorene (abbreviation: DPA2SF), 4,4',4''-tris[N-(1-naphthyl)-N-phenylamino]triphenylamine (abbreviation: 1'-TNATA), 4,4',4''-tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4',4''-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: m-MTDATA), N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviation: DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: B nfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4′-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4″-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl] -4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4''-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-(6;2'-binaphthyl-2 -yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyl triphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazol-9-yl)phenyl]tris(1,1'-biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazol-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), bis-biphenyl-4'-(carbazol-9-yl)biphenylamine ( Abbreviation: YGBBi1BP), N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N-bis([1,1'-biphenyl]-4-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis([1,1'-biphenyl]-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(1,1'-biphenyl-2- N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine amine (abbreviation: BPAFLBi), N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-1-amine, and the like.

[0066] Other examples of the second organic compound that can be used include polymer compounds (oligomers, dendrimers, polymers, etc.) such as poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD). Alternatively, polymer compounds to which an acid has been added, such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (abbreviation: PEDOT / PSS) and polyaniline / poly(styrenesulfonic acid) (abbreviation: PAni / PSS), can also be used.

[0067] The active layer 213 is preferably a laminated film of a first layer having a first organic compound and a second layer having a second organic compound.

[0068] Moreover, the active layer 213 is preferably a mixed film containing a first organic compound and a second organic compound.

[0069] Next, another configuration of the light-receiving device 200 according to one embodiment of the present invention will be described with reference to FIG. 1C.

[0070] <First Electrode and Second Electrode> The first electrode 201 and the second electrode 202 can be formed using a material that can be used for the first electrode 101 and the second electrode 102 of a light-emitting device, which will be described later in Embodiment 2.

[0071] For example, if the first electrode 201 is a reflective electrode and the second electrode 202 is a semi-transparent and semi-reflective electrode, a micro-optical resonator (microcavity) structure can be formed, which intensifies light of a specific wavelength to be detected, resulting in a highly sensitive light-receiving device.

[0072] <First Carrier Injection Layer> The first carrier injection layer 211 is a layer that injects holes from the light-receiving layer 203 to the first electrode 201 and is a layer containing a material with high hole injection properties. Examples of the material with high hole injection properties include an aromatic amine compound and a composite material containing a hole-transporting material and an acceptor material (electron-accepting material).

[0073] The first carrier injection layer 211 can be formed using a material that can be used for the hole injection layer 111 of the light-emitting device, which will be described later in Embodiment 2.

[0074] <First Carrier Transport Layer> The first carrier transport layer 212 is a layer that transports holes generated in the active layer 213 based on incident light to the first electrode 201, and is a layer that contains a hole transport material. −６ cm ２ A substance having a hole mobility of 1 / Vs or more is preferred. Note that other substances can also be used as long as they have a higher hole transporting property than an electron transporting property. In this specification and the like, the first carrier transporting layer may also be referred to as a hole transporting layer.

[0075] As the hole transporting material, a π-electron rich heteroaromatic compound or an aromatic amine (a compound having an aromatic amine skeleton) can be used.

[0076] As the hole transporting material, a carbazole derivative, a thiophene derivative, or a furan derivative can be used.

[0077] Alternatively, the hole transporting material is an aromatic monoamine compound or a heteroaromatic monoamine compound, and includes at least one structure of biphenylamine, carbazolylamine, dibenzofuranylamine, dibenzothiophenylamine, fluorenylamine, or spirofluorenylamine.

[0078] Alternatively, the hole transporting material is an aromatic monoamine compound or a heteroaromatic monoamine compound, and has two or more skeletons selected from biphenylamine, carbazolylamine, dibenzofuranylamine, dibenzothiophenylamine, fluorenylamine, and spirofluorenylamine.

[0079] In addition, when the hole transport material is an aromatic monoamine compound or a heteroaromatic monoamine compound and has two or more skeletons selected from biphenylamine, carbazolylamine, dibenzofuranylamine, dibenzothiophenylamine, fluorenylamine, and spirofluorenylamine, one nitrogen atom may be contained in two or more skeletons. For example, in an aromatic monoamine compound, when fluorene and biphenyl are bonded to the nitrogen of the monoamine, the compound can be said to be an aromatic monoamine compound having a fluorenylamine structure and a biphenylamine structure.

[0080] The biphenylamine, carbazolylamine, dibenzofuranylamine, dibenzothiophenylamine, fluorenylamine, and spirofluorenylamine described above as the skeleton of the hole-transporting material may have a substituent. Examples of the substituent include a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms, a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having from 1 to 20 carbon atoms, and a substituted or unsubstituted heteroaryl group having from 4 to 30 carbon atoms.

[0081] Alternatively, the hole transporting material is preferably a monoamine compound having a triarylamine skeleton (the aryl group in the triarylamine compound includes a heteroaryl group), for example, an organic compound represented by the following general formula (Gh-1):

[0082]

[0083] In the above general formula (Gh-1), Ar １１ ~Ar １３each independently represents hydrogen, a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having from 4 to 30 carbon atoms.

[0084] Alternatively, the hole transporting material is an organic compound represented by the following general formula (Gh-2).

[0085]

[0086] In the above general formula (Gh-2), Ar １２ and Ar １３ each independently represents hydrogen, a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having from 4 to 30 carbon atoms; R ５１１ ~R ５２０ represents hydrogen, a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms, a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having from 1 to 20 carbon atoms, or a substituted or unsubstituted heteroaryl group having from 4 to 30 carbon atoms; R ５１９ and R ５２０ The substituents may be bonded to each other to form a ring.

[0087] Alternatively, the hole transporting material is an organic compound represented by the following general formula (Gh-3).

[0088]

[0089] In the above general formula (Gh-3), Ar １２ and Ar １３ each independently represents a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having from 4 to 30 carbon atoms; R ５２１ ~R ５３６ represents hydrogen, a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms, a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having from 1 to 20 carbon atoms, or a substituted or unsubstituted heteroaryl group having from 4 to 30 carbon atoms.

[0090] Alternatively, the hole transporting material is an organic compound represented by the following general formula (Gh-4).

[0091]

[0092] In the above general formula (Gh-4), Ar １３ represents a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having from 4 to 30 carbon atoms; R ５１１ ~R ５２０ and R ５４０ ~R ５４９ represents hydrogen, a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms, a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having from 1 to 20 carbon atoms, or a substituted or unsubstituted heteroaryl group having from 4 to 30 carbon atoms; R ５１９ and R ５２０ The substituents may be bonded to each other to form a ring, and R ５４８ and R ５４９ The substituents may be bonded to each other to form a ring.

[0093] Alternatively, the hole transporting material is an organic compound represented by the following general formula (Gh-5).

[0094]

[0095] In the above general formula (Gh-5), Ar １３ represents a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having from 4 to 30 carbon atoms; R ５１１ ~R ５２０ and R ５５０ ~R ５５９ represents hydrogen, a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms, a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having from 1 to 20 carbon atoms, or a substituted or unsubstituted heteroaryl group having from 4 to 30 carbon atoms; R ５１９ and R ５２０ The substituents may be bonded to each other to form a ring.

[0096] Alternatively, the hole transporting material is an organic compound represented by the following general formula (Gh-6).

[0097]

[0098] In the above general formula (Gh-6), R ５６０ ~R ５７４ each independently represents hydrogen, a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms, a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having from 1 to 20 carbon atoms, or a substituted or unsubstituted heteroaryl group having from 4 to 30 carbon atoms.

[0099] R in the above general formula (Gh-2) ５１１ ~R ５２０ , R in the above general formula (Gh-3) ５２１ ~R ５３６ , R in the above general formula (Gh-4) ５１１ ~R ５２０ and R ５４０ ~R ５４９ , R in the above general formula (Gh-5) ５１１ ~R ５２０ and R ５５０ ~R ５５９ and R in the general formula (Gh-6) ５６０ ~R ５７４ each independently represents, in addition to the above-mentioned substituents, a halogen, a substituted or unsubstituted halogenated alkyl group having 1 to 13 carbon atoms, a cyano group, or a substituted or unsubstituted alkoxy group having 1 to 13 carbon atoms.

[0100] R in the above general formula (Gh-2) ５１１ ~R ５２０ , R in the above general formula (Gh-3) ５２１ ~R ５３６ , R in the above general formula (Gh-4) ５１１ ~R ５２０ and R ５４０ ~R ５４９ , R in the above general formula (Gh-5) ５１１ ~R ５２０ and R ５５０ ~R ５５９ and R in the general formula (Gh-6) ５６０ ~R ５７４Specifically, it is preferable that R is a substituent represented by the following formulae (R-1) to (R-38) and (R-41) to (R-117), where * represents a bond.

[0101] In addition, Ar in the above general formula (Gh-1) １１ ~Ar １３ , Ar in the above general formulae (Gh-2) and (Gh-3) １２ and Ar １３ and Ar in the general formulae (Gh-4) and (Gh-5) １３ Specifically, it is preferable that R is a substituent represented by the following formulae (R-41) to (R-117): In the formulae, * represents a bond.

[0102]

[0103]

[0104]

[0105]

[0106]

[0107] Next, specific examples of the organic compounds (hole transporting materials) represented by the above general formulae (Gh-1) to (Gh-6) are shown below.

[0108]

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118] The organic compounds represented by the structural formulas (201) to (302) are examples of organic compounds (hole-transporting materials) represented by the general formulas (Gh-1) to (Gh-6). However, specific examples of hole-transporting materials that can be used for the first carrier-transporting layer 212 are not limited to these.

[0119] The first carrier transport layer 212 can also be formed using a material that can be used for the hole transport layer 112 of the light-emitting device, which will be described later in Embodiment 2.

[0120] The first carrier transport layer 212 may be not only a single layer, but also a laminated structure of two or more layers made of the above-mentioned materials.

[0121] In the light-receiving device described in this embodiment, the active layer 213 can be formed using the same organic compound as that of the first carrier transport layer 212. Using the same organic compound for the first carrier transport layer 212 and the active layer 213 is more preferable because carriers can be efficiently transported from the first carrier transport layer 212 to the active layer 213.

[0122] <Buffer Layer> As described above, the light-receiving layer 203 may have a buffer layer between the active layer 213 and the second carrier transport layer 214. By providing the buffer layer, an increase in the driving voltage of the light-receiving device 200 can be suppressed.

[0123] The buffer layer can use an organic compound whose LUMO level is higher than the LUMO level of the first organic compound contained in the active layer 213 and lower than the LUMO level of the electron transport material contained in the second carrier transport layer 214. By using such an organic compound for the buffer layer, the carrier injection barrier from the active layer 213 to the second carrier transport layer 214 can be reduced, and an increase in the driving voltage of the light-receiving device 200 can be suppressed.

[0124] Furthermore, the difference between the LUMO level of the organic compound in the buffer layer and the LUMO level of the first organic compound contained in the active layer 213 is preferably 0.5 eV or less. The buffer layer facilitates the acceptance of electrons from the active layer 213, and can prevent holes and electrons from recombining in the active layer 213.

[0125] The difference between the LUMO level of the organic compound in the buffer layer and the LUMO level of the electron-transporting material in the second carrier-transporting layer 214 is preferably 1 eV or less. The buffer layer can easily provide electrons to the second carrier-transporting layer 214.

[0126] For example, the LUMO level of the organic compound contained in the buffer layer is preferably −4.5 eV or more and −3.0 eV or less.

[0127] Specific examples of organic compounds having a LUMO level of −4.5 eV or more and −3.0 eV or less that can be used for the buffer layer include pyrazino[2,3-f][1,10]phenanthroline-2,3-dicarbonitrile (abbreviation: PPDN), 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), diquinoxalino[2,3-a:2′,3′-c]phenazine (abbreviation: HATNA), and 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2′,3′-c]phenazine (abbreviation: HATNA-F6). However, the organic compounds having a LUMO level of −4.5 eV or more and −3.0 eV or less that can be used for the buffer layer are not limited to these.

[0128] The organic compound that can be used for the buffer layer is not limited to an organic compound having a LUMO level of −4.5 eV or more and −3.0 eV or less. It is preferable to use an organic compound having an appropriate LUMO level for the buffer layer depending on the LUMO level of the first organic compound used for the active layer 213 and the LUMO level of the electron transport material used for the second carrier transport layer 214.

[0129] Furthermore, an organic compound having an electron-withdrawing group can be used for the buffer layer. An organic compound having an electron-withdrawing group has acceptor properties. Therefore, by using an organic compound having an electron-withdrawing group for the buffer layer, it becomes easier to receive electrons from the active layer 213 and to donate electrons to the second carrier transport layer 214, and an increase in the driving voltage of the light-receiving device 200 can be suppressed.

[0130] Examples of the electron-withdrawing group include a halogen group (such as a fluoro group, a chloro group, or an iodine group), a cyano group, an isocyanate group, a nitro group, a halogenated alkyl group, a halogenated cycloalkyl group, a carbonyl group, a carboxy group, and an acyl group. In particular, the use of an organic compound having a cyano group in the buffer layer is highly effective in suppressing an increase in the driving voltage of the light-receiving device 200, and is therefore preferable.

[0131] As the organic compound having an electron-withdrawing group, a heteroaromatic compound having an electron-withdrawing group can be used. Specific examples of heteroaromatic compounds having an electron-withdrawing group include 2-cyanopyridine, 3-cyanopyridine, 4-cyanopyridine, pyrazino[2,3-f][1,10]phenanthroline-2,3-dicarbonitrile (abbreviation: PPDN), 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 2,3-bis(4-fluorophenyl)pyrido[2,3-b]pyrazine (abbreviation: F2PYPR), and 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2′,3′-c]phenazine (abbreviation: HATNA-F6).

[0132] Among the heteroaromatic compounds having the above electron-withdrawing groups, heteroaromatic compounds having a plurality of cyano groups bonded thereto, such as PPDN and HAT-CN, are particularly preferred because of their higher acceptor properties.

[0133] Furthermore, among the heteroaromatic compounds having the above-mentioned electron-withdrawing groups, heteroaromatic compounds having condensed heteroaromatic rings such as PPDN, HAT-CN, F2PYPR, and HATNA-F6 are particularly suitable because the film quality is very stable against heat.

[0134] Other specific examples of organic compounds having an electron-withdrawing group include benzonitrile, 7,7,8,8-tetracyanoquinodimethane (abbreviation: TCNQ), 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F ４ -TCNQ), 3,6-difluoro-2,5,7,7,8,8-hexacyanoquinodimethane, chloranil, 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F ６ -TCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile, perfluoropentacene, copper hexadecafluorophthalocyanine (abbreviation: F １６ CuPc), N,N'-bis(2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluorooctyl)-1,4,5,8-naphthalenetetracarboxylic acid diimide (abbreviation: NTCDI-C8F), 3',4'-dibutyl-5,5"-bis(dicyanomethylene)-5,5"-dihydro-2,2':5',2"-terthiophene (abbreviation: DCMT), 1,4,5,8-naphthalenetetracarboxylic acid dianhydride (abbreviation: NTCDA), and the like can be used. In addition, [3]radialene derivatives having an electron-withdrawing group are preferred because they have extremely high acceptor properties. Specifically, α,α',α''-1,2,3-cyclopropanetriylidene tris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidene tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidene tris[2,3,4,5,6-pentafluorobenzeneacetonitrile], and the like can be used.

[0135] It is also preferable to use an organic compound for the buffer layer that has an electron-withdrawing group and a LUMO level that is higher than the LUMO level of the first organic compound contained in the active layer 213 and lower than the LUMO level of the electron-transporting material contained in the second carrier transport layer 214. By using such an organic compound for the buffer layer, the effect of suppressing an increase in the driving voltage of the light-receiving device 200 can be further enhanced.

[0136] It is also preferable to use an organic compound for the buffer layer, which has a LUMO level higher than that of the first organic compound contained in the active layer 213 and lower than that of the electron transport material contained in the second carrier transport layer 214, and which has an electron-withdrawing group. By using such an organic compound for the buffer layer, the effect of suppressing an increase in the driving voltage of the light-receiving device 200 can be further enhanced.

[0137] <Second Carrier Transport Layer> The second carrier transport layer 214 is a layer that transports electrons generated in the active layer 213 based on incident light to the second electrode 202, and is a layer that contains an electron transport material. −６ cm ２ A substance having an electron mobility of 1 / Vs or more is preferred. Note that other substances can also be used as long as they have a higher electron transporting property than a hole transporting property. In this specification and the like, the second carrier transporting layer may also be referred to as an electron transporting layer.

[0138] As the electron transporting material, a π-electron deficient heteroaromatic compound can be used.

[0139] In addition, as the electron transporting material, metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, and the like, as well as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other π-electron-deficient heteroaromatic compounds including nitrogen-containing heteroaromatic compounds can be used.

[0140] Alternatively, the electron transporting material is a compound having a triazine ring.

[0141] Alternatively, the electron transporting material is an organic compound represented by the following general formula (Ge-1).

[0142]

[0143] In the above general formula (Ge-1), Ar １ ~Ar ３ each independently represents hydrogen, a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having from 2 to 30 carbon atoms; X １ and X ２ each independently represents carbon or nitrogen; X １ and X ２ When either one or both of the above is carbon, the carbon is bonded to hydrogen, or a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having from 2 to 30 carbon atoms, a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms, or a substituted or unsubstituted cycloalkyl group having from 1 to 20 carbon atoms.

[0144] Alternatively, the electron transporting material is an organic compound represented by the following general formula (Ge-2).

[0145]

[0146] In the above general formula (Ge-2), Ar １ ~Ar ３each independently represents a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms; X ２ represents carbon or nitrogen, and X ２ is a carbon, the carbon is bonded to hydrogen, or a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having from 2 to 30 carbon atoms, a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms, or a substituted or unsubstituted cycloalkyl group having from 1 to 20 carbon atoms.

[0147] Alternatively, the electron transporting material is an organic compound represented by the following general formula (Ge-3).

[0148]

[0149] In the above general formula (Ge-3), Ar １ ~Ar ３ each independently represents a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having from 2 to 30 carbon atoms.

[0150] Alternatively, the electron transporting material is an organic compound represented by the following general formula (Ge-4).

[0151]

[0152] In the above general formula (Ge-4), Ar ３ each independently represents a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms; R １ ~R １０ each independently represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms.

[0153] R in the above general formula (Ge-4) １ ~R １０represents, in addition to the above-mentioned substituents, a halogen, a substituted or unsubstituted halogenated alkyl group having 1 to 13 carbon atoms, a cyano group, or a substituted or unsubstituted alkoxy group having 1 to 13 carbon atoms.

[0154] R in the above general formula (Ge-4) １ ~R １０ is preferably a substituent represented by the following formulas (R-1) to (R-38), a substituent represented by the following formulas (R-41) to (R-116), or a substituent represented by the following formulas (R-118) to (R-131).

[0155] In addition, Ar in the above general formulas (Ge-1) to (Ge-3) １ ~Ar ３ and Ar in the general formula (Ge-4) ３ is preferably a substituent represented by the following formulae (R-41) to (R-116) and a substituent represented by the following formulae (R-118) to (R-131).

[0156]

[0157]

[0158]

[0159]

[0160]

[0161]

[0162] Next, specific examples of the electron transporting material having the above-mentioned structures will be shown below.

[0163]

[0164]

[0165] The organic compounds represented by the structural formulas (500) to (524) are examples of the organic compounds represented by the general formulas (Ge-1) to (Ge-4), but specific examples of electron transporting materials that can be used for the second carrier transporting layer 214 are not limited to these.

[0166] In addition, as the electron transporting material, organic compounds represented by the following structural formulas (600) to (622) can be used.

[0167]

[0168]

[0169] The second carrier transport layer 214 can also be formed using a material that can be used for the electron transport layer 114 of the light-emitting device, which will be described later in Embodiment 2.

[0170] The second carrier transport layer 214 may be not only a single layer, but also a laminated structure of two or more layers made of the above-mentioned materials.

[0171] <Second Carrier Injection Layer> The second carrier injection layer 215 is a layer for increasing the efficiency of electron injection from the light-receiving layer 203 to the second electrode 202, and is a layer containing a material with high electron injection properties. As the material with high electron injection properties, an alkali metal, an alkaline earth metal, or a compound thereof can be used. As the material with high electron injection properties, a composite material containing an electron-transporting material and a donor material (electron-donating material) can also be used.

[0172] The second carrier injection layer 215 can be formed using a material that can be used for the electron injection layer 115 of the light-emitting device, which will be described later in Embodiment 2.

[0173] Furthermore, by providing a charge generation layer between the two light-receiving layers 203, a structure in which a plurality of light-receiving layers are stacked between a pair of electrodes (also referred to as a tandem structure) can be formed. Furthermore, by providing a charge generation layer between different light-receiving layers, a stacked structure of three or more light-receiving layers can be formed. The charge generation layer can be formed using a material that can be used for the charge generation layer 106 of the light-emitting device, which will be described later in Embodiment 2.

[0174] The materials of the layers constituting the light-receiving layer 203 of the light-receiving device described in this embodiment (the first carrier injection layer 211, the first carrier transport layer 212, the active layer 213, the second carrier transport layer 214, and the second carrier injection layer 215) are not limited to those described in this embodiment, and other materials can also be used in combination as long as they can fulfill the functions of the respective layers.

[0175] In this specification and the like, the terms "layer" and "film" can be used interchangeably as appropriate.

[0176] Note that the light-receiving device of one embodiment of the present invention has a function of detecting visible light. Moreover, the light-receiving device of one embodiment of the present invention is sensitive to visible light. Furthermore, the light-receiving device of one embodiment of the present invention more preferably has a function of detecting visible light and infrared light. Furthermore, the light-receiving device of one embodiment of the present invention is preferably sensitive to visible light and infrared light.

[0177] In this specification, the blue (B) wavelength range is defined as 400 nm or more and less than 490 nm, and blue (B) light has at least one emission spectrum peak in this wavelength range. The green (G) wavelength range is defined as 490 nm or more and less than 580 nm, and green (G) light has at least one emission spectrum peak in this wavelength range. The red (R) wavelength range is defined as 580 nm or more and less than 700 nm, and red (R) light has at least one emission spectrum peak in this wavelength range. In this specification, the visible light wavelength range is defined as 400 nm or more and less than 700 nm, and visible light has at least one emission spectrum peak in this wavelength range. The infrared (IR) wavelength range is defined as 700 nm or more and less than 900 nm, and infrared (IR) light has at least one emission spectrum peak in this wavelength range.

[0178] The light-receiving device of one embodiment of the present invention described above can be used in a display device using an organic EL device. In other words, the light-receiving device of one embodiment of the present invention can be built into a display device using an organic EL device. As an example, FIG. 3A shows a schematic cross-sectional view of a light-receiving and light-emitting device 810 in which a light-emitting device 805a and a light-receiving device 805b are formed on the same substrate.

[0179] The light receiving and emitting device 810 has a light emitting device 805a and a light receiving device 805b, and therefore has one or both of an imaging function and a sensing function in addition to a function of displaying an image.

[0180] The light-emitting device 805a has a function of emitting light (hereinafter also referred to as a light-emitting function). The light-emitting device 805a has an electrode 801a, an EL layer 803a, and an electrode 802. The EL layer 803a sandwiched between the electrode 801a and the electrode 802 has at least a light-emitting layer. The light-emitting layer contains a light-emitting substance. Light is emitted from the EL layer 803a by applying a voltage between the electrode 801a and the electrode 802. The EL layer 803a may have various layers in addition to the light-emitting layer, such as a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a carrier (hole or electron) blocking layer, and a charge generation layer. The light-emitting device 805a can have the configuration of a light-emitting device, which is an organic EL device described later in Embodiment 2.

[0181] The light-receiving device 805b has a function of detecting light (hereinafter also referred to as a light-receiving function). The light-receiving device 805b has an electrode 801b, a light-receiving layer 803b, and an electrode 802. The light-receiving layer 803b sandwiched between the electrode 801b and the electrode 802 has at least an active layer. The light-receiving device 805b functions as a photoelectric conversion device, and can generate charges by light incident on the light-receiving layer 803b and extract them as current. At this time, a voltage may be applied between the electrode 801b and the electrode 802. The amount of generated charges is determined based on the amount of light incident on the light-receiving layer 803b. The configuration of the light-receiving device 200 described above can be applied to the light-receiving device 805b.

[0182] The light-receiving device 805b can be easily made thin, lightweight, and large-area, and has a high degree of freedom in shape and design, so it can be applied to various display devices. In addition, the EL layer 803a of the light-emitting device 805a and the light-receiving layer 803b of the light-receiving device 805b can be formed by the same method (e.g., vacuum deposition), which is preferable because a common manufacturing apparatus can be used.

[0183] The electrode 801a and the electrode 801b are provided on the same surface. Fig. 3A shows a configuration in which the electrode 801a and the electrode 801b are provided on a substrate 800. Note that the electrode 801a and the electrode 801b can be formed, for example, by processing a conductive film formed on the substrate 800 into an island shape. In other words, the electrode 801a and the electrode 801b can be formed through the same process.

[0184] A heat-resistant substrate capable of withstanding the formation of the light-emitting device 805 a and the light-receiving device 805 b can be used as the substrate 800. When an insulating substrate is used as the substrate 800, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, an organic resin substrate, or the like can be used. In addition, a semiconductor substrate such as a single-crystal semiconductor substrate made of silicon, silicon carbide, or the like, a polycrystalline semiconductor substrate, a compound semiconductor substrate such as silicon germanium, or an SOI substrate can be used.

[0185] In particular, it is preferable to use the above-mentioned insulating substrate or a substrate on which a semiconductor circuit including a semiconductor element such as a transistor is formed as the substrate 800. The semiconductor circuit preferably constitutes, for example, a pixel circuit, a gate line driving circuit (gate driver), a source line driving circuit (source driver), etc. In addition to the above, an arithmetic circuit, a memory circuit, etc. may also be configured.

[0186] The electrode 802 is an electrode made of a layer common to the light-emitting device 805a and the light-receiving device 805b. Of the electrodes 801a, 801b, and 802, a conductive film that transmits visible light and infrared light is used for the electrode that emits light or that receives light. It is preferable to use a conductive film that reflects visible light and infrared light for the electrode that does not emit light or that does not receive light.

[0187] The electrode 802 in the light-emitting and receiving device of one embodiment of the present invention functions as one electrode of each of the light-emitting device 805a and the light-receiving device 805b.

[0188] 3B shows a case where electrode 801a of light-emitting device 805a has a higher potential than electrode 802. In this case, electrode 801a functions as the anode of light-emitting device 805a, and electrode 802 functions as the cathode. Furthermore, electrode 801b of light-receiving device 805b has a lower potential than electrode 802. Note that in FIG. 3B, to make it easier to understand the direction of current flow, the circuit symbol for a light-emitting diode is shown to the left of light-emitting device 805a, and the circuit symbol for a photodiode is shown to the right of light-receiving device 805b. Furthermore, the direction of carrier (electron and hole) flow is schematically indicated by arrows in each device.

[0189] In the configuration shown in FIG. 3B, when a first potential is supplied to electrode 801a via a first wiring, a second potential is supplied to electrode 802 via a second wiring, and a third potential is supplied to electrode 801b via a third wiring, the relationship in magnitude of each potential is first potential > second potential > third potential.

[0190] 3C also shows a case where electrode 801a of light-emitting device 805a has a lower potential than electrode 802. In this case, electrode 801a functions as the cathode of light-emitting device 805a, and electrode 802 functions as the anode. Furthermore, electrode 801b of light-receiving device 805b has a lower potential than electrode 802 and a higher potential than electrode 801a. Note that in FIG. 3C, to make it easier to understand the direction of current flow, the circuit symbol for a light-emitting diode is shown to the left of light-emitting device 805a, and the circuit symbol for a photodiode is shown to the right of light-receiving device 805b. The direction of carrier (electron and hole) flow is also indicated by a schematic arrow in each device.

[0191] In the configuration shown in FIG. 3C, when a first potential is supplied to electrode 801a via a first wiring, a second potential is supplied to electrode 802 via a second wiring, and a third potential is supplied to electrode 801b via a third wiring, the relationship in magnitude of each potential is second potential > third potential > first potential.

[0192] 4A shows a light-receiving and light-emitting device 810A, which is a modified example of the light-receiving and light-emitting device 810. The light-receiving and light-emitting device 810A differs from the light-receiving and light-emitting device 810 in that it includes a common layer 806 and a common layer 807. In the light-emitting device 805a, the common layer 806 and the common layer 807 function as part of the EL layer 803a. In the light-receiving device 805b, the common layer 806 and the common layer 807 function as part of the light-receiving layer 803b. The common layer 806 includes, for example, a hole injection layer and a hole transport layer. The common layer 807 includes, for example, an electron transport layer and an electron injection layer.

[0193] By adopting a configuration including the common layer 806 and the common layer 807, it is possible to incorporate a light receiving device without significantly increasing the number of times of coating, and it is possible to manufacture the light receiving and emitting device 810A with high throughput.

[0194] FIG. 4B shows a light-receiving and light-emitting device 810B, which is a modification of the light-receiving and light-emitting device 810. The light-receiving and light-emitting device 810B differs from the light-receiving and light-emitting device 810A in that the EL layer 803a includes layers 806a and 807a, and the light-receiving layer 803b includes layers 806b and 807b. The layers 806a and 806b are made of different materials and include, for example, a hole injection layer and a hole transport layer. The layers 806a and 806b may be made of the same material. The layers 807a and 807b are made of different materials and include, for example, an electron transport layer and an electron injection layer. The layers 807a and 807b may be made of the same material.

[0195] By selecting the most suitable materials for constituting the light-emitting device 805a for the layers 806a and 807a, and the most suitable materials for constituting the light-receiving device 805b for the layers 806b and 807b, the performance of each of the light-emitting device 805a and the light-receiving device 805b in the light-receiving and light-emitting device 810B can be improved.

[0196] The resolution of the light receiving device 805b may be 100 ppi or more, preferably 200 ppi or more, more preferably 300 ppi or more, more preferably 400 ppi or more, and even more preferably 500 ppi or more, and may be 2000 ppi or less, 1000 ppi or less, or 600 ppi or less. In particular, by arranging the light receiving device 805b with a resolution of 200 ppi to 600 ppi, preferably 300 ppi to 600 ppi, the light receiving device 805b can be suitably used for capturing fingerprint images. When fingerprint authentication is performed using the light receiving and emitting device 810, increasing the resolution of the light receiving device 805b can, for example, extract fingerprint minutia with high accuracy, thereby improving the accuracy of fingerprint authentication. Furthermore, a resolution of 500 ppi or higher is preferable because it allows compliance with standards such as those of the National Institute of Standards and Technology (NIST). Assuming that the resolution of the light-receiving device is 500 ppi, the size per pixel is 50.8 μm, which is sufficient resolution for capturing an image of the width of a fingerprint (typically, 300 μm to 500 μm).

[0197] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0198] Embodiment Mode 2 In this embodiment mode, a structure of a light-emitting device will be described with reference to FIGS. 5A to 5E.

[0199] <<Basic Structure of Light-Emitting Device>> The basic structure of a light-emitting device will be described. Fig. 5A shows a light-emitting device 100 having an EL layer including a light-emitting layer between a pair of electrodes. Specifically, the light-emitting device has a structure in which an EL layer 103 is sandwiched between a first electrode 101 and a second electrode 102.

[0200] 5B shows a light-emitting device having a stacked structure (tandem structure) in which a plurality of EL layers (103a, 103b) (two layers in FIG. 5B) are provided between a pair of electrodes and a charge generation layer 106 is provided between the EL layers. A light-emitting device with a tandem structure can be realized as a light-emitting device that can be driven at a low voltage and consumes low power.

[0201] The charge generation layer 106 has a function of injecting electrons into one EL layer (103a or 103b) and injecting holes into the other EL layer (103b or 103a) when a potential difference is generated between the first electrode 101 and the second electrode 102. Therefore, in Fig. 5B, when a voltage is applied to the first electrode 101 so that the potential is higher than that of the second electrode 102, electrons are injected from the charge generation layer 106 into the EL layer 103a and holes are injected into the EL layer 103b.

[0202] 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.

[0203] 5C also shows a stacked structure of the EL layer 103 of the light-emitting device according to one embodiment of the present invention. In this case, the first electrode 101 functions as an anode, and the second electrode 102 functions as a cathode. The EL layer 103 has a structure in which a hole injection layer 111, a hole transport layer 112, a light-emitting layer 113, an electron transport layer 114, and an electron injection layer 115 are sequentially stacked over the first electrode 101. The light-emitting layer 113 may have a stacked structure of multiple light-emitting layers that emit different colors. For example, a light-emitting layer containing a red light-emitting substance, a light-emitting layer containing a green light-emitting substance, and a light-emitting layer containing a blue light-emitting substance may be stacked, or may have a structure in which the layers are stacked with a layer containing a carrier transport material interposed therebetween. Alternatively, a light-emitting layer containing a yellow light-emitting substance and a light-emitting layer containing a blue light-emitting substance may be combined. However, the stacked structure of the light-emitting layer 113 is not limited to the above. For example, the light-emitting layer 113 may be configured by stacking multiple light-emitting layers emitting the same light color. For example, a first light-emitting layer containing a blue light-emitting material and a second light-emitting layer containing a blue light-emitting material may be stacked, or a layer containing a carrier transport material may be interposed between the layers. A configuration in which multiple light-emitting layers emitting the same light color are stacked may provide higher reliability than a single-layer configuration. Even in a tandem structure such as that shown in FIG. 5B , where multiple EL layers are included, each EL layer is stacked sequentially from the anode side as described above. Furthermore, when the first electrode 101 is a cathode and the second electrode 102 is an anode, the stacking order of the EL layer 103 is reversed. Specifically, the structure includes an electron injection layer 111 on the first electrode 101 (cathode), an electron transport layer 112, an emitting layer 113, a hole transport layer 114, and a hole injection layer 115.

[0204] The light-emitting layer 113 included in the EL layer (103, 103a, 103b) has an appropriate combination of multiple substances including a light-emitting substance, 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 that emits different light 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 light-emitting colors are emitted from the multiple EL layers (103a, 103b) shown in FIG. 5B 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.

[0205] In the light-emitting device according to one embodiment of the present invention, for example, the first electrode 101 shown in FIG. 5C is a reflective electrode, the second electrode 102 is a semi-transmissive and semi-reflective electrode, and a micro-optical resonator (microcavity) structure is formed. This allows light emission from the light-emitting layer 113 included in the EL layer 103 to resonate between the two electrodes, thereby enhancing the light emission from the second electrode 102.

[0206] 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.

[0207] Furthermore, in order to amplify the desired light (wavelength: λ) obtained from the light-emitting layer 113, it is preferable to adjust the optical distance from the first electrode 101 to the region (light-emitting region) in the light-emitting layer 113 where the desired light is obtained and the optical distance from the second electrode 102 to the region (light-emitting region) in the light-emitting layer 113 where the desired light is obtained to be (2m'+1)λ / 4 (where m' is an integer of 1 or more) or close to that. Note that the light-emitting region referred to here refers to a recombination region of holes and electrons in the light-emitting layer 113.

[0208] 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.

[0209] 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.

[0210] The light-emitting device shown in FIG. 5D is a light-emitting device with a tandem structure and a microcavity structure, which allows light of different wavelengths (monochromatic light) to be extracted from each EL layer (103a, 103b). Therefore, separate coloring (e.g., RGB) to obtain different emitted colors is not required. Therefore, high definition can be easily achieved. It can also be combined with a colored layer (color filter). Furthermore, it is possible to increase the emission intensity of a specific wavelength in the front direction, thereby reducing power consumption.

[0211] The light-emitting device shown in FIG. 5E is an example of the tandem-structure light-emitting device shown in FIG. 5B , and as shown in the figure, has a structure in which three EL layers (103a, 103b, 103c) are stacked with charge generation layers (106a, 106b) sandwiched between them. The three EL 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.

[0212] 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.

[0213] 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.

[0214] <<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. 5D , which has a tandem structure. The same applies to the single-structure light-emitting devices shown in FIGS. 5A and 5C . When the light-emitting device shown in FIG. 5D 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 102 can be formed as a single layer or a stacked layer using a single or multiple desired electrode materials. The second electrode 102 is formed by selecting a material in the same manner as described above after the EL layer 103b is formed.

[0215] <First Electrode and Second Electrode> The materials forming the first electrode 101 and the second electrode 102 can be appropriately combined from the following materials as long as they fulfill the functions of both electrodes described above. For example, metals, alloys, electrically conductive compounds, and mixtures thereof can be appropriately used. Specific examples include In-Sn oxide (also referred to as ITO), In-Si-Sn oxide (also referred to as ITSO), In-Zn oxide, and In-W-Zn oxide. Other metals that can be used include aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), and neodymium (Nd), as well as alloys containing appropriate combinations of these metals. Other examples that can be used include elements belonging to Group 1 or 2 of the periodic table (e.g., lithium (Li), cesium (Cs), calcium (Ca), and strontium (Sr)) that are not listed above, rare earth metals such as europium (Eu) and ytterbium (Yb), and alloys containing appropriate combinations of these, as well as graphene.

[0216] 5D , when the first electrode 101 is an anode, the hole injection layer 111a and the hole transport layer 112a of the EL layer 103a are sequentially laminated by vacuum deposition on the first electrode 101. After the EL layer 103a and the charge generation layer 106 are formed, the hole injection layer 111b and the hole transport layer 112b of the EL layer 103b are similarly sequentially laminated on the charge generation layer 106.

[0217] <Hole injection layer> The hole injection layer (111, 111a, 111b) is a layer that injects holes from the first electrode 101, which is an anode, and the charge generation layer (106, 106a, 106b) to the EL layer (103, 103a, 103b), and is a layer that contains an organic acceptor material or a material with high hole injection properties.

[0218] An organic acceptor material is a material that can generate holes in an organic compound by causing charge separation between the organic acceptor material and another organic compound whose LUMO level and HOMO level are close to each other. Therefore, as the organic acceptor material, a compound having an electron-withdrawing group (e.g., a halogen group, a cyano group), such as a quinodimethane derivative, a chloranil derivative, or a hexaazatriphenylene derivative, can be used. For example, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviated as F ４Examples of organic acceptor materials that can be used include 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCCNNQ), and 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile. Among organic acceptor materials, compounds such as HAT-CN in which an electron-withdrawing group is bonded to a fused aromatic ring having multiple heteroatoms are particularly suitable because of their high acceptor properties and stable film quality against heat. In addition, [3]radialene derivatives having an electron-withdrawing group (particularly a halogen group such as a fluoro group, a cyano group, or the like) are preferred because they have extremely high electron-accepting properties. Specifically, α,α',α''-1,2,3-cyclopropanetriylidene tris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidene tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidene tris[2,3,4,5,6-pentafluorobenzeneacetonitrile], and the like can be used.

[0219] As a material with high hole injection properties, oxides of metals belonging to Groups 4 to 8 of the periodic table (transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, manganese oxide, etc.) can be used. Specific examples include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among the above, molybdenum oxide is preferred because it is stable in the air, has low hygroscopicity, and is easy to handle. In addition, phthalocyanine (abbreviated as H ２ Phthalocyanine compounds such as copper phthalocyanine (abbreviated as CuPc) can be used.

[0220] In addition to the above materials, low molecular weight compounds such as 4,4',4''-tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4',4''-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: MTDATA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviation: DNTPD), and 1,3,5- Aromatic amine compounds such as tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), 3-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), and 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1) can be used.

[0221] Also usable are polymer compounds (oligomers, dendrimers, polymers, etc.), such as poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD). Alternatively, polymer compounds to which an acid has been added, such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (abbreviation: PEDOT / PSS) and polyaniline / poly(styrenesulfonic acid) (abbreviation: PAni / PSS), can also be used.

[0222] Furthermore, as the material with high hole injection properties, a mixed material containing a hole transport material and the above-mentioned organic acceptor material (electron accepting material) can also be used. In this case, electrons are extracted from the hole transport material by the organic acceptor material, generating holes in the hole injection layer 111, and the holes are injected into the light-emitting layer 113 via the hole transport layer 112. Note that the hole injection layer 111 may be formed as a single layer made of a mixed material containing the hole transport material and the organic acceptor material (electron accepting material), or may be formed by laminating the hole transport material and the organic acceptor material (electron accepting material) as separate layers.

[0223] The hole transport material has a hole mobility of 1×10 when the square root of the electric field strength [V / cm] is 600. −６ cm ２ A substance having a hole mobility of 1 / Vs or more is preferred. Note that other substances can also be used as long as they have a higher hole transporting property than electron transporting property.

[0224] As the hole-transporting material, a material with high hole-transporting properties, such as a compound having a π-electron-rich heteroaromatic ring (e.g., a carbazole derivative, a furan derivative, a thiophene derivative, etc.) or an aromatic amine (an organic compound having an aromatic amine skeleton), is preferred.

[0225] Examples of the carbazole derivatives (organic compounds having a carbazole ring) include bicarbazole derivatives (for example, 3,3'-bicarbazole derivatives), aromatic amines having a carbazolyl group, and the like.

[0226] Specific examples of the bicarbazole derivatives (e.g., 3,3′-bicarbazole derivatives) include 3,3′-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), 9,9′-bis(biphenyl-4-yl)-3,3′-bi-9H-carbazole (abbreviation: BisBPCz), 9,9′-bis(1,1′-biphenyl-3-yl)-3,3′-bi-9H-carbazole (abbreviation: BismBPCz), 9-(1,1′-biphenyl-3-yl)-9′-(1,1′-biphenyl-4-yl)-9H,9′H-3,3′-bicarbazole (abbreviation: mBPCCBP), and 9-(2-naphthyl)-9′-phenyl-9H,9′H-3,3′-bicarbazole (abbreviation: βNCCP).

[0227] Specific examples of the aromatic amine having a carbazolyl group include 4-phenyl-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazol-3-amine (abbreviation: PCBiF), N-(1,1′-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)]- ...triphenylamine (abbreviation: PCBiF), N-(1,1′-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)]-triphenylamine (abbreviation: PCBA1BP), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-triphenylamine (abbreviation: PCBiF), N-(1,1′-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)]-triphenylamine (abbreviation: PCBA1BP), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-triphenylamine (abbreviation: PCBA1BP), N-(4-biphenyl)-N-(9,9 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: PCBBiF), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4,4'-di(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: PCBBiF), 4,4'-diphenyl ... N,N'-bis(9-phenylcarbazol-3-yl)-N,N'-diphenylbenzene-1,3-diamine (abbreviation: PCA2B), N,N',N''-triphenyl-N,N',N''-tris(9-phenylcarbazol-3-yl)benzene-1,3,5-triamine (abbreviation: PCA3B), 9-phenyldiphenylamine (abbreviation: PCBNBB), 4-phenyldiphenyl-(9-phenyl-9H-carbazol-3-yl)amine (abbreviation: PCA1BP), ... ,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]spiro-9,9′-bifluoren-2-amine (abbreviation: PCBASF), 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), 3-[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA1), 3,6-bis[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA2), 3,6-bis[N-(4-diphenylaminophenyl)-N-(1 -naphthyl)amino]-9-phenylcarbazole (abbreviation: PCzTPN2), 2-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: PCASF), N-[4-(9H-carbazol-9-yl)phenyl]-N-(4-phenyl)phenylaniline (abbreviation: YGA1BP), N,N'-bis[4-(carbazol-9-yl)phenyl]-N,N'-diphenyl-9,9-dimethylfluorene-2,7-diamine (abbreviation: YGA2F), 4,4',4''-tris(carbazol-9-yl)triphenylamine (abbreviation: TCTA), and the like.

[0228] In addition to the above, examples of the carbazole derivatives include 3-[4-(9-phenanthryl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPPn), 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4′-di(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviation: TCPB), and 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA).

[0229] Specific examples of the furan derivatives (organic compounds having a furan ring) include 4,4′,4″-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II).

[0230] Specific examples of the thiophene derivative (organic compound having a thiophene ring) include organic compounds having a thiophene ring, such as 4,4′,4″-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV).

[0231] Specific examples of the aromatic amine include 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB or α-NPD), N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1′-biphenyl]-4,4′-diamine (abbreviation: TPD), 4,4′-bis[N-(spiro-9,9′-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP ... N-(4-biphenyl)-N-{4-[(9-phenyl)-9H-fluoren-9-yl]-phenyl}-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: FBiFLP), N,N,N',N'-tetrakis(4-biphenyl)-1,1-biphenyl-4,4'-diamine (abbreviation: BBA2BP), N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: SF ４FAF), N-(9,9-dimethyl-9H-fluoren-2-yl)-N-{9,9-dimethyl-2-[N'-phenyl-N'-(9,9-dimethyl-9H-fluoren-2-yl)amino]-9H-fluoren-7-yl}phenylamine (abbreviation: DFLADFL), N-(9,9-dimethyl-2-diphenylamino-9H-fluoren-7-yl)diphenylamine (abbreviation: DPNF), 2-[N-(4-diphenylaminophenyl)-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: DPASF), 2,7-bis[N-(4 N,N'-diphenylaminophenyl)-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: DPA2SF), 4,4',4''-tris[N-(1-naphthyl)-N-phenylamino]triphenylamine (abbreviation: 1'-TNATA), 4,4',4''-tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4',4''-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: m-MTDATA), N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenyl Nylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), DNTPD, 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABn f), 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4''-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthyl-2-yl)triphenylamine phenylamine (abbreviation: BBAαNβNB), 4,4′-diphenyl-4″-(7;1′-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4′-diphenyl-4″-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4′-diphenyl-4″-(6;2′-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4′-diphenyl-4″-(7;2′-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2) B-03), 4,4'-diphenyl-4''-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-( 4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazol-9-yl)phenyl]tris(1,1'-biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazol-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), bis-biphenyl-4'-(carbazol-9-yl)biphenylamine (abbreviation: YGBBi1BP), N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi[9H -fluorene]-2-amine (abbreviation: PCBNBSF), N,N-bis([1,1′-biphenyl]-4-yl)-9,9′-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis([1,1′-biphenyl]-4-yl)-9,9′-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(1,1′-biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9′-spirobi[9H-fluorene]-4 -amine (abbreviation: oFBiSF), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), N,N-bis(9,9- Examples thereof include N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-2-amine, and N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-1-amine.

[0232] Other examples of hole-transporting materials that can be used include polymer compounds (oligomers, dendrimers, polymers, etc.) such as poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD). Alternatively, polymer compounds to which an acid has been added, such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (abbreviation: PEDOT / PSS) and polyaniline / poly(styrenesulfonic acid) (abbreviation: PAni / PSS), can also be used.

[0233] However, the hole transporting material is not limited to the above, and various known materials may be used alone or in combination as the hole transporting material.

[0234] The hole injection layers (111, 111a, 111b) can be formed using various known film formation methods, for example, vacuum deposition.

[0235] <Hole transport layer> The hole transport layer (112, 112a, 112b) is a layer that transports holes injected from the first electrode 101 by the hole injection layer (111, 111a, 111b) to the light-emitting layer (113, 113a, 113b, 113c). The hole transport layer (112, 112a, 112b) is a layer that contains a hole transport material. Therefore, the hole transport layer (112, 112a, 112b) can be made of the same hole transport material that can be used for the hole injection layer (111, 111a, 111b).

[0236] In the light-emitting device of one embodiment of the present invention, the same organic compound as that of the hole-transport layer (112, 112a, 112b) can be used for the light-emitting layer (113, 113a, 113b, 113c). It is more preferable to use the same organic compound for the hole-transport layer (112, 112a, 112b) and the light-emitting layer (113, 113a, 113b, 113c) because holes can be efficiently transported from the hole-transport layer (112, 112a, 112b) to the light-emitting layer (113, 113a, 113b, 113c).

[0237] <Light-emitting layer> The light-emitting layers (113, 113a, 113b, 113c) are layers containing a light-emitting substance. Note that, as the light-emitting substance that can be used for the light-emitting layers (113, 113a, 113b, 113c), a substance that emits light of a color such as blue, purple, blue-purple, green, yellow-green, yellow, orange, or red can be appropriately used. Furthermore, when a plurality of light-emitting layers are provided, a structure that emits different light colors (for example, white light emission obtained by combining light-emitting colors that are complementary to each other) can be obtained by using different light-emitting substances for each light-emitting layer. Furthermore, a stacked structure in which one light-emitting layer contains different light-emitting substances may be used.

[0238] The light-emitting layers (113, 113a, 113b, 113c) may contain one or more organic compounds (host materials, etc.) in addition to the light-emitting substance (guest material).

[0239] When a plurality of host materials are used in the light-emitting layer (113, 113a, 113b, 113c), it is preferable to use a substance having a larger energy gap than the energy gaps of the existing guest material and the first host material as the newly added second host material. Furthermore, it is preferable that the lowest singlet excitation energy level (S1 level) of the second host material is higher than the S1 level of the first host material, and the lowest triplet excitation energy level (T1 level) of the second host material is higher than the T1 level of the guest material. Furthermore, it is preferable that the lowest triplet excitation energy level (T1 level) of the second host material is higher than the T1 level of the first host material. With this structure, an exciplex can be formed using two types of host materials. To efficiently form an exciplex, it is particularly preferable to combine a compound that easily accepts holes (hole-transporting material) with a compound that easily accepts electrons (electron-transporting material). Furthermore, this structure can simultaneously achieve high efficiency, low voltage, and long life.

[0240] As the organic compound used as the host material (including the first host material and the second host material), as long as it satisfies the conditions for a host material used in an emitting layer, examples thereof include organic compounds such as hole-transporting materials that can be used in the hole-transporting layer (112, 112a, 112b) described above and electron-transporting materials that can be used in the electron-transporting layer (114, 114a, 114b) described below. Also, an exciplex composed of multiple organic compounds (the first host material and the second host material described above) may be used. An exciplex (also referred to as an exciplex) that forms an excited state with multiple organic compounds has an extremely small difference between the S1 level and the T1 level and functions as a TADF material that can convert triplet excitation energy to singlet excitation energy. Furthermore, as a combination of multiple organic compounds that form an exciplex, for example, one of the compounds has a π-electron-deficient heteroaromatic ring and the other has a π-electron-rich heteroaromatic ring. As a combination for forming an exciplex, one of the compounds may be a phosphorescent material such as an iridium, rhodium, or platinum-based organometallic complex or a metal complex.

[0241] The light-emitting substance that can be used in the light-emitting layer (113, 113a, 113b, 113c) is not particularly limited, and a light-emitting substance that converts singlet excitation energy into light emission in the visible light region, or a light-emitting substance that converts triplet excitation energy into light emission in the visible light region can be used.

[0242] <Light-emitting substance that converts singlet excitation energy into light emission> Examples of light-emitting substances that can be used in the light-emitting layers (113, 113a, 113b, 113c) and that convert singlet excitation energy into light emission include the following fluorescent substances (fluorescent light-emitting substances). Examples 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, and naphthalene derivatives. Pyrene derivatives are particularly preferred because of their high light emission quantum yield. Specific examples of the pyrene derivative include N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), (N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine) (abbreviation: 1,6FLPAPrn), N,N'-bis(dibenzofuran-2-yl)-N,N'-diphenylpyrene-1,6-diamine (abbreviation: 1,6FrAPrn), and N,N'-bis(dibenzothiophen-2-yl)-N , N'-diphenylpyrene-1,6-diamine (abbreviation: 1,6ThAPrn), N,N'-(pyrene-1,6-diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-6-amine] (abbreviation: 1,6BnfAPrn), N,N'-(pyrene-1,6-diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-02), N,N'-(pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), and the like.

[0243] In addition, 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′-bis[4-(9H-carbazol-9-yl)phenyl]-N,N′-diphenylstilbene-4,4′-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)phenyl]- N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), 4-(10-phenyl-9-anthryl)-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), 4-(10-phenyl-9-anthryl)-4'- (9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), 4-[4-(10-phenyl-9-anthryl)phenyl]-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPBA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenyl) N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: 2PCAPPA), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), and the like can be used.

[0244] Further, N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPhA), 9,10-bis(1,1'-biphenyl- 2-yl)-N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracen-9-amine (abbreviation: DPhAPhA), Coumarin 545T, N,N'-diphenylquinacridone, (abbreviation: DPQd), rubrene, 5,12-bis(1,1'-biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyran-4-yl N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhTD), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM2), N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p -mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2,6-bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJ™), 1,6BnfAP rn-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), etc. In particular, pyrene diamine compounds such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03 can be used.

[0245] <Light-Emitting Substance Converting Triplet Excitation Energy into Light Emission> Next, examples of light-emitting substances that convert triplet excitation energy into light emission and that can be used in the light-emitting layer 113 include phosphorescent substances (phosphorescent light-emitting substances) and thermally activated delayed fluorescence (TADF) materials that exhibit thermally activated delayed fluorescence.

[0246] A phosphorescent material refers to a compound that exhibits phosphorescence but does not exhibit fluorescence at a temperature range from low temperature (e.g., 77 K) to room temperature (i.e., 77 K to 313 K). The phosphorescent material preferably contains a metal element with a large spin-orbit interaction, such as an organometallic complex, a metal complex (platinum complex), or a rare earth metal complex. Specifically, a transition metal element is preferred, and a platinum group element (ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), or platinum (Pt)) is particularly preferred. Among these, iridium is preferred because it can increase the transition probability associated with the direct transition between the singlet ground state and the triplet excited state.

[0247] <Phosphorescent Substances (450 nm to 570 nm: Blue or Green)> Examples of phosphorescent substances that exhibit blue or green and have an emission spectrum with a peak wavelength of 450 nm to 570 nm include the following substances.

[0248] For example, 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 complexes having a 4H-triazole ring 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 complexes having a 1H-triazole ring such as fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpmi) ３ ]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me) ３]), organometallic complexes having an imidazole ring such as bis[2-(4',6'-difluorophenyl)pyridinato-N,C2']iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridinato-N,C2']iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinato-N,C2']iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), ２’} Iridium(III) picolinate (abbreviation: [Ir(CF ３ ppy) ２ (pic)]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C ２’ ] Examples include organometallic complexes having a phenylpyridine derivative having an electron-withdrawing group as a ligand, such as iridium(III) acetylacetonate (abbreviation: FIr(acac)).

[0249] <Phosphorescent Substances (495 nm or More and 590 nm or Less: Green or Yellow)> Examples of phosphorescent substances that exhibit green or yellow and have an emission spectrum with a peak wavelength of 495 nm or more and 590 nm or less include the following substances.

[0250] For example, 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[6-(2-norbornyl)-4-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 ring, 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 ring, 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)]), bis[2-(2-pyridinyl-κN)phenyl-κC][2-(4-phenyl-2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy) ２ (4dppy)]), bis[2-(2-pyridinyl-κN)phenyl-κC][2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC], [2-d ３ -methyl-8-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(5-d ３ [5-methyl-2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(5mppy-d ３ ) ２ (mbfpypy-d ３ )), [2-(methyl-d ３ )-8-[4-(1-methylethyl-1-d)-2-pyridinyl-κN]benzofuro[2,3-b]pyridin-7-yl-κC]bis[5-(methyl-d ３ )-2-[5-(methyl-d ３ )-2-pyridinyl-κN]phenyl-κC]iridium(III) (abbreviation: Ir(5mtpy-d ６ ) ２ (mbfpypy-iPr-d ４ )), [2-d ３ -methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy) ２ (mbfpypy-d ３ )), [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy) ２ organometallic iridium complexes having a pyridine ring, such as bis(2,4-diphenyl-1,3-oxazolato-N,C (mdppy)); 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 complexes such as tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: [Tb(acac)]), ３ (Phen)]).

[0251] <Phosphorescent Substances (570 nm to 750 nm: Yellow or Red)> Examples of phosphorescent substances that exhibit yellow or red and have an emission spectrum with a peak wavelength of 570 nm to 750 nm include the following substances.

[0252] For example, (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)]), (dipivaloylmethanato)bis[4,6-di(naphthalen-1-yl)pyrimidinato]iridium(III) (abbreviation: [Ir(dpm)] ２ organometallic complexes having a pyrimidine ring 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)]), bis{4,6-dimethyl-2-[3-(3,5-dimethylphenyl)-5-phenyl-2-pyrazinyl-κN]phenyl-κC}(2,6-dimethyl-3,5-heptanedionato-κ ２ O,O')iridium(III) (abbreviation: [Ir(dmdppr-P) ２(dibm)]), bis{4,6-dimethyl-2-[5-(4-cyano-2,6-dimethylphenyl)-3-(3,5-dimethylphenyl)-2-pyrazinyl-κN]phenyl-κC}(2,2,6,6-tetramethyl-3,5-heptanedionato-κ ２ O,O′)iridium(III) (abbreviation: [Ir(dmdppr-dmCP) ２ (dpm)]), bis[2-(5-(2,6-dimethylphenyl)-3-(3,5-dimethylphenyl)-2-pyrazinyl-κN)-4,6-dimethylphenyl-κC](2,2′,6,6′-tetramethyl-3,5-heptanedionato-κO,O′)iridium(III) (abbreviation: [Ir(dmdppr-dmp) ２ (dpm)]), (acetylacetonato)bis[2-methyl-3-phenylquinoxalinato-N,C ２’ ]iridium(III) (abbreviation: [Ir(mpq) ２ (acac)]), (acetylacetonato)bis(2,3-diphenylquinoxalinato-N,C ２’ ) Iridium(III) (abbreviation: [Ir(dpq) ２ (acac)]), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq) ２ organometallic complexes having a pyrazine ring, 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 (acac)]), bis[4,6-dimethyl-2-(2-quinolinyl-κN)phenyl-κC](2,4-pentanedionato-κ ２ O,O')iridium(III) (abbreviation: [Ir(dmpqn) ２(acac)]), platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrinplatinum(II) (abbreviation: [PtOEP]), or 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 (Phen)]).

[0253] <TADF Material> The following materials can be used as the TADF material. A TADF material is a material that has a small difference between the S1 level and the T1 level (preferably 0.2 eV or less), can upconvert a triplet excited state to a singlet excited state with a small amount of thermal energy (reverse intersystem crossing), and efficiently emits light (fluorescence) from the singlet excited state. Conditions for efficiently obtaining thermally activated delayed fluorescence include an energy difference between the triplet excited energy level and the singlet excited energy level of 0 eV or more and 0.2 eV or less, preferably 0 eV or more and 0.1 eV or less. The delayed fluorescence in a TADF material refers to light emission that has a spectrum similar to that of ordinary fluorescence but has a significantly long lifetime. Its lifetime is 1 x 10 −６ seconds or more, preferably 1×10 −３ More than a second.

[0254] Examples of TADF materials include fullerene and its derivatives, acridine derivatives such as proflavine, and eosin. Also, examples of metal-containing porphyrins include those containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd). Examples of metal-containing porphyrins include protoporphyrin-tin fluoride complexes (abbreviated as SnF ２ (Proto IX)), mesoporphyrin-tin fluoride complex (abbreviation: SnF ２(Meso IX)), hematoporphyrin-tin fluoride complex (abbreviation: SnF ２ (Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (abbreviation: SnF ２ (Copro III-4Me)), octaethylporphyrin-tin fluoride complex (abbreviation: SnF ２ (OEP)), etioporphyrin-tin fluoride complex (abbreviation: SnF ２ (Etio I)), octaethylporphyrin-platinum chloride complex (abbreviation: PtCl ２ OEP) and the like.

[0255]

[0256] Other 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-phenoxy) 3-[4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN), bis[4-(9, 9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthracen]-10'-one (abbreviation: ACRSA), 4-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)benzofuro[3,2-d]pyrimidine (abbreviation: 4PCCzBfpm), 4-[4-(9'-phenyl-3,3'- Heteroaromatic compounds having a π-electron rich heteroaromatic compound and a π-electron deficient heteroaromatic compound, such as 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9′-phenyl-2,3′-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), may also be used.

[0257] In addition, a substance in which a π-electron-rich heteroaromatic compound and a π-electron-deficient heteroaromatic compound are directly bonded is particularly preferable because the donor property of the π-electron-rich heteroaromatic compound and the acceptor property of the π-electron-deficient heteroaromatic compound are both strong, and the energy difference between the singlet excited state and the triplet excited state is small. Furthermore, a TADF material (TADF100) in which the singlet excited state and the triplet excited state are in thermal equilibrium may be used as the TADF material. Such a TADF material has a short emission lifetime (excitation lifetime), which can suppress a decrease in the efficiency of a light-emitting element in a high-brightness region.

[0258]

[0259] In addition to the above, examples of materials capable of converting triplet excitation energy into luminescence include nanostructures of transition metal compounds having a perovskite structure. Nanostructures of metal halide perovskites are particularly preferred. Nanoparticles and nanorods are preferred as such nanostructures.

[0260] In the light-emitting layers (113, 113a, 113b, 113c), one or more substances having an energy gap larger than the energy gap of the light-emitting substance (guest material) may be selected and used as the organic compound (host material or the like) used in combination with the above-mentioned light-emitting substance (guest material).

[0261] <Fluorescent Host Material> When the light-emitting substance used in the light-emitting layer (113, 113a, 113b, 113c) is a fluorescent light-emitting substance, it is preferable to use, as the organic compound (host material) to be combined, an organic compound having a high energy level in a singlet excited state and a low energy level in a triplet excited state, or an organic compound with a high fluorescence quantum yield. Therefore, as long as the organic compound satisfies these conditions, one or more selected from the hole-transporting material (described above) and the electron-transporting material (described below) shown in this embodiment can be used.

[0262] Although some of the examples overlap with those described above, examples of the organic compound (host material) from the viewpoint of a preferable combination with the light-emitting substance (fluorescent light-emitting substance) include condensed polycyclic aromatic compounds such as anthracene derivatives, tetracene derivatives, phenanthrene derivatives, pyrene derivatives, chrysene derivatives, and dibenzo[g,p]chrysene derivatives.

[0263] Specific examples of organic compounds (host materials) that are preferably used in combination with fluorescent materials include 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA), 3,6-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: DPCzPA), 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 9,10-diphenylanthracene (abbreviation: DPAnth), N,N-diphenylanthracene (abbreviation: DPAnth), and N,N-diphenylanthracene (abbreviation: DPAnth). N-nyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: CzA1PA), 4-(10-phenyl-9-anthryl)triphenylamine (abbreviation: DPhPA), YGAPA, PCAPA, N,9-diphenyl-N-{4-[4-(10-phenyl-9-anthryl)phenyl]phenyl}-9H-carbazole-3-amine (abbreviation: PCAPBA), N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCAPA), 6,12-dimethoxy-5,11-diphenylchrysene, N,N,N',N',N'',N'',N''',N'''-octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]-benzyl benzo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10-{4-(9-phenyl-9H-fluoren-9-yl)-biphenyl-4'-yl}-anthracene (abbreviation: FLPPA), 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviation: α,β-ADN), 2-(10-phenylanthracen-9-yl)dibenzofuran, 2-(10-phenyl-9-anthracenyl)-benzo[b]naphtho[2,3-d]furan (abbreviation: Bnf(II)PhA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth), 9-(2-naphthyl)-10-[3-(2-naphthyl)phenyl]anthracene (abbreviation: βN-mβNPAnth), 1-[4-(10-[1,1′-biphenyl]-4-yl-9 -anthracenyl)phenyl]-2-ethyl-1H-benzimidazole (abbreviation: EtBImPBPhA), 9,9'-bianthryl (abbreviation: BANT), 9,9'-(stilbene-3,3'-diyl)diphenanthrene (abbreviation: DPNS), 9,9'-(stilbene-4,4'-diyl)diphenanthrene (abbreviation: DPNS2), 1,3,5-tri(1-pyrenyl)benzene (abbreviation: TPB3), 5,12-diphenyltetracene, 5,12-bis(biphenyl-2-yl)tetracene, etc.

[0264] <Phosphorescent Host Material> When the light-emitting substance used in the light-emitting layers (113, 113a, 113b, 113c) is a phosphorescent substance, an organic compound having a triplet excitation energy greater than the triplet excitation energy (energy difference between the ground state and the triplet excited state) of the light-emitting substance can be selected as the organic compound (host material) to be combined. When a plurality of organic compounds (e.g., a first host material and a second host material (or assist material)) are used in combination with the light-emitting substance to form an exciplex, it is preferable to use these plurality of organic compounds as a mixture with the phosphorescent substance.

[0265] With this structure, light emission can be efficiently obtained using Exciplex-Triple Energy Transfer (ExTET), which is energy transfer from an exciplex to a light-emitting substance. It is preferable to combine a plurality of organic compounds that easily form an exciplex, and it is particularly preferable to combine a compound that easily accepts holes (hole transport material) with a compound that easily accepts electrons (electron transport material).

[0266] Although some of the organic compounds (host materials, assist materials) overlap with the above-mentioned specific examples, from the viewpoint of a preferable combination with the light-emitting substance (phosphorescent light-emitting substance), examples thereof include aromatic amines (organic compounds having an aromatic amine skeleton), carbazole derivatives (organic compounds having a carbazole ring), dibenzothiophene derivatives (organic compounds having a dibenzothiophene ring), dibenzofuran derivatives (organic compounds having a dibenzofuran ring), oxadiazole derivatives (organic compounds having an oxadiazole ring), triazole derivatives (organic compounds having a triazole ring), benzimidazole derivatives (benzoin derivatives), and the like. midazole ring), quinoxaline (organic compound having a quinoxaline ring) derivatives, dibenzoquinoxaline derivatives (organic compounds having a dibenzoquinoxaline ring), pyrimidine derivatives (organic compounds having a pyrimidine ring), triazine derivatives (organic compounds having a triazine ring), pyridine derivatives (organic compounds having a pyridine ring), bipyridine derivatives (organic compounds having a bipyridine ring), phenanthroline derivatives (organic compounds having a phenanthroline ring), furodiazine derivatives (organic compounds having a furodiazine ring), zinc or aluminum metal complexes, and the like.

[0267] Among the organic compounds, specific examples of the aromatic amine and carbazole derivative, which are organic compounds with high hole-transporting properties, are the same as the specific examples of the hole-transporting material described above, and any of these is preferable as the host material.

[0268] Specific examples of the dibenzothiophene derivatives and dibenzofuran derivatives, which are organic compounds with high hole transport properties among the above organic compounds, include 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II), 4,4′,4″-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II), DBT3P-II, 2,8-dipheny Examples of such compounds include 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), all of which are preferable as the host material.

[0269] Other preferred host materials include metal complexes having an oxazole-based or thiazole-based ligand, such as bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO) and bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ).

[0270] Specific examples of the organic compounds having high electron transport properties, such as oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, quinazoline derivatives, and phenanthroline derivatives, among the above organic compounds, include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl 3-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4'-bis(5-methylbenzoxazole) organic compounds containing heteroaromatic rings having a polyazole ring, such as 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2'-(1,3-phenylene)bis[9-phenyl-1,10-phenanthroline] (abbreviation: mPPhen2P), 2-phenyl-9-[4-[4-(9-phenyl-1,10-phenanthrolin-2-yl)phenyl]phenyl]- Organic compounds containing heteroaromatic rings with a pyridine ring, such as 1,10-phenanthroline (abbreviation: PPhen2BP), 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-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),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: 6mDBTPDB q-II), 2-{4-[9,10-di(2-naphthyl)-2-anthryl]phenyl}-1-phenyl-1H-benzimidazole (abbreviation: ZADN), 2-[4′-(9-phenyl-9H-carbazol-3-yl)-3,1′-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), and the like, all of which are preferred as host materials.

[0271] Specific examples of the pyridine derivatives, diazine derivatives (including pyrimidine derivatives, pyrazine derivatives, and pyridazine derivatives), triazine derivatives, and furodiazine derivatives, which are organic compounds with high electron transport properties among the above organic compounds, include 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-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), and 4,6-bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II). 4,6mCzP2Pm), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3 -(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), 9,9'-[pyrimidine-4,6-diylbis(biphenyl-3,3'-diyl)]bis(9H-carbazole) (abbreviation: 4,6mCzBP2Pm), 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)-1,1'-biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 8-(1,1'-biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d ]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 9-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 9-[(3'-dibenzothiophen-4-yl)biphenyl-4-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9pmDBtBPNfpr), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-[3′-(triphenylen-2-yl)-1,1′-biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mTpBPTzn), 2-[(1,1′-biphenyl)-4-yl]-4-phenyl-6-[9,9′-spirobi(9H-fluoren)-2-yl]-1 ,3,5-triazine (abbreviation: BP-SFTzn), 2,6-bis(4-naphthalen-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzothiophenyl]-2-phenyl-9H-carbazole (abbreviation: PC and organic compounds containing a heteroaromatic ring having a diazine ring, such as 2-[1,1'-biphenyl]-3-yl-4-phenyl-6-(8-[1,1':4',1''-terphenyl]-4-yl-1-dibenzofuranyl)-1,3,5-triazine (abbreviation: mBP-TPDBfTzn), 6-(1,1'-biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), and 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(1,1'-biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), all of which are preferred as host materials.

[0272] Specific examples of metal complexes, which are organic compounds with high electron transport properties among the above organic compounds, include zinc- or aluminum-based metal complexes such as tris(8-quinolinolato)aluminum(III) (abbreviation: Alq) and tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq). ３ ), bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq ２), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq), as well as metal complexes having a quinoline ring or a benzoquinoline ring, and the like, all of which are preferable as the host material.

[0273] Other preferred host materials include polymer compounds such as poly(2,5-pyridinediyl) (abbreviation: PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviation: PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2′-bipyridine-6,6′-diyl)] (abbreviation: PF-BPy).

[0274] Furthermore, bipolar 9-phenyl-9′-(4-phenyl-2-quinazolinyl)-3,3′-bi-9H-carbazole (abbreviation: PCCzQz), 2-[4′-(9-phenyl-9H-carbazole-3-yl)-3,1′-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), 5-[3-(4,6-diphenyl-1,3,5-triazin-2yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1

[0049] Organic compounds having a diazine ring, such as 11-(4-[1,1′-biphenyl]-4-yl-6-phenyl-1,3,5-triazin-2-yl)-11,12-dihydro-12-phenyl-indolo[2,3-a]carbazole (abbreviation: mINc(II)PTzn), 11-(4-[1,1′-biphenyl]-4-yl-6-phenyl-1,3,5-triazin-2-yl)-11,12-dihydro-12-phenyl-indolo[2,3-a]carbazole (abbreviation: BP-Icz(II)Tzn), and 7-[4-(9-phenyl-9H-carbazol-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: PC-cgDBCzQz), can also be used as the host material.

[0275] <Electron Transport Layer> The electron transport layer (114, 114a, 114b) is a layer that transports electrons injected from the second electrode 102 and the charge generation layer (106, 106a, 106b) by the electron injection layer (115, 115a, 115b) described later to the light-emitting layer (113, 113a, 113b, 113c). The electron transport material used for the electron transport layer (114, 114a, 114b) has an electron mobility of 1×10 or less at a square root of an electric field strength [V / cm] of 600. −６ cm ２ A substance having an electron mobility of 1 / Vs or higher is preferred. Note that other substances can be used as long as they have a higher electron transporting property than holes. The electron transport layer (114, 114a, 114b) functions as a single layer, but may also have a stacked structure of two or more layers. Note that the above mixed materials have heat resistance, and therefore, by performing a photolithography process on the electron transport layer using such a mixed material, the influence of a thermal process on the device characteristics can be suppressed.

[0276] <Electron Transporting Material> As the electron transporting material that can be used in the electron transporting layer (114, 114a, 114b), an organic compound with high electron transporting properties can be used, for example, a heteroaromatic compound. A heteroaromatic compound is a cyclic compound containing at least two different elements in a ring. The ring structure includes a three-membered ring, a four-membered ring, a five-membered ring, a six-membered ring, etc., but a five-membered ring or a six-membered ring is particularly preferred. The contained element is preferably a heteroaromatic compound containing one or more of nitrogen, oxygen, sulfur, or the like in addition to carbon. In particular, a nitrogen-containing heteroaromatic compound (nitrogen-containing heteroaromatic compound) is preferred, and it is preferable to use a material with high electron transporting properties (electron transporting material) such as a nitrogen-containing heteroaromatic compound or a π-electron-deficient heteroaromatic compound containing the same.

[0277] A heteroaromatic compound is an organic compound that contains at least one heteroaromatic ring.

[0278] The heteroaromatic ring has any one of a pyridine ring, a diazine ring, a triazine ring, a polyazole ring, an oxazole ring, a thiazole ring, etc. The heteroaromatic ring having a diazine ring includes a heteroaromatic ring having a pyrimidine ring, a pyrazine ring, a pyridazine ring, etc. The heteroaromatic ring having a polyazole ring includes a heteroaromatic ring having an imidazole ring, a triazole ring, or an oxadiazole ring.

[0279] The heteroaromatic ring also includes a fused heteroaromatic ring having a fused ring structure, such as a quinoline ring, a benzoquinoline ring, a quinoxaline ring, a dibenzoquinoxaline ring, a quinazoline ring, a benzoquinazoline ring, a dibenzoquinazoline ring, a phenanthroline ring, a phlodiazin ring, or a benzimidazole ring.

[0280] Examples of heteroaromatic compounds include heteroaromatic compounds containing one or more of nitrogen, oxygen, and sulfur in addition to carbon, and examples of heteroaromatic compounds having a five-membered ring structure include heteroaromatic compounds having an imidazole ring, heteroaromatic compounds having a triazole ring, heteroaromatic compounds having an oxazole ring, heteroaromatic compounds having an oxadiazole ring, heteroaromatic compounds having a thiazole ring, and heteroaromatic compounds having a benzimidazole ring.

[0281] Furthermore, among heteroaromatic compounds containing one or more of nitrogen, oxygen, and sulfur in addition to carbon, examples of heteroaromatic compounds having a six-membered ring structure include heteroaromatic compounds having a heteroaromatic ring such as a pyridine ring, a diazine ring (including a pyrimidine ring, a pyrazine ring, and a pyridazine ring), a triazine ring, and a polyazole ring.Heteroaromatic compounds having a structure in which pyridine rings are linked include heteroaromatic compounds having a bipyridine structure and heteroaromatic compounds having a terpyridine structure.

[0282] Furthermore, examples of heteroaromatic compounds having a fused ring structure partially containing the above-mentioned 6-membered ring structure include heteroaromatic compounds having a fused heteroaromatic ring such as a quinoline ring, a benzoquinoline ring, a quinoxaline ring, a dibenzoquinoxaline ring, a phenanthroline ring, a furodiazine ring (including a structure in which an aromatic ring is fused to the furan ring of a furodiazine ring), and a benzimidazole ring.

[0283] Specific examples of the heteroaromatic compound having a five-membered ring structure (such as a polyazole ring (including an imidazole ring, a triazole ring, and an oxadiazole ring), an oxazole ring, a thiazole ring, and a benzimidazole ring) include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 3-(4-biphenylyl)-4-furan (abbreviation: OXD-7 ... phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenylyl)-1,2,4-triazole (abbreviation: p-EtTAZ), 2,2′,2″-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4′-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs), and the like.

[0284] Specific examples of the heteroaromatic compound having a 6-membered ring structure (including a heteroaromatic ring having a pyridine ring, a diazine ring, a triazine ring, or the like) include heteroaromatic compounds having a pyridine ring, such as 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy) and 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB); Triazine (abbreviation: PCCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-[3'-(triphenylen-2-yl)-1,1'-biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine ( abbreviation: mTpBPTzn), 2-[(1,1'-biphenyl)-4-yl]-4-phenyl-6-[9,9'-spirobi(9H-fluoren)-2-yl]-1,3,5-triazine (abbreviation: BP-SFTzn), 2,6-bis(4-naphthalen-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzothiophenyl]-2-phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-[1,1'-biphenyl]-4-yl]-4-phenyl-6-[9,9'-spirobi(9H-fluoren)-2-yl]-1,3,5-triazine (abbreviation: BP-SFTzn), 2,6-bis(4-naphthalen-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), heteroaromatic compounds containing a heteroaromatic ring having a triazine ring, such as [3-(3-(dibenzothiophen-4-yl)phenyl]phenyl]-3-yl-4-phenyl-6-(8-[1,1':4',1''-terphenyl]-4-yl-1-dibenzofuranyl)-1,3,5-triazine (abbreviation: mBP-TPDBfTzn), 2-{3-[3-(dibenzothiophen-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTzn), and mFBPTzn; 4,6-bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm);6-Bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 4,6mCzBP2Pm, 6-(1,1'-biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2 PPm), 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(1,1'-biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 4-[3-(dibenzothiophen-4-yl)phenyl]-8-(naphthalen-2-yl)-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8βN-4mDBtPBfpm), 8BP-4mDBtPBfpm, 9mDBtBP Nfpr, 9pmDBtBPNfpr, 3,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzofuro[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3′-(dibenzothiophen-4-yl)(1,1′-biphenyl- and heteroaromatic compounds containing a heteroaromatic ring having a diazine (pyrimidine) ring, such as 8-[(2,2'-binaphthalen)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm). The aromatic compounds containing a heteroaromatic ring include heteroaromatic compounds having a fused heteroaromatic ring.

[0285] Other examples include 2,2'-(pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6(P-Bqn)2Py), 2,2'-(2,2'-bipyridine-6,6'-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 6,6'(P-Bqn)2BPy), 2,2'-(pyridine-2,6-diyl)bis{4-[4-(2-naphthyl)phenyl]-6-phenylpyrimidine} (abbreviation: 2,6(NP-PPm)2Py), and 6-(1,1' heteroaromatic compounds containing a heteroaromatic ring having a diazine (pyrimidine) ring, such as 2,4,6-tris(3′-(pyridin-3-yl)biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm); heteroaromatic compounds containing a heteroaromatic ring having a triazine ring, such as 2,4,6-tris(3′-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine (abbreviation: TmPPPyTz), 2,4,6-tris(2-pyridyl)-1,3,5-triazine (abbreviation: 2Py3Tz), and 2-[3-(2,6-dimethyl-3-pyridyl)-5-(9-phenanthryl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTzn).

[0286] Specific examples of the heteroaromatic compound having a fused ring structure partially containing a 6-membered ring structure (heteroaromatic compound having a fused ring structure) include bathophenanthroline (abbreviation: Bphen), bathocuproine (abbreviation: BCP), 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2′-(1,3-phenylene)bis[9-phenyl-1,10-phenanthroline] (abbreviation: NBphen), mPPhen2P), 2-phenyl-9-[4-[4-(9-phenyl-1,10-phenanthrolin-2-yl)phenyl]phenyl]-1,10-phenanthroline (abbreviation: PPhen2BP), 2,2'-(pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6(P-Bqn)2Py), 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxa Phosphorus (abbreviation: 2mDBTPDBq-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), 2mpPCBPDBq, and other heteroaromatic compounds having a quinoxaline ring.

[0287] In addition to the heteroaromatic compounds described above, the electron transport layers (114, 114a, 114b) may also include the following metal complexes: tris(8-quinolinolato)aluminum(III) (abbreviation: Alq ３ ), Almq ３ , 8-quinolinolatolithium (I) (abbreviation: Liq), BeBq ２metal complexes having a quinoline ring or a benzoquinoline ring, such as bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq) and bis(8-quinolinolato)zinc(II) (abbreviation: Znq); and metal complexes having an oxazole ring or a thiazole ring, such as bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO) and bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ).

[0288] Furthermore, polymer compounds such as poly(2,5-pyridinediyl) (abbreviation: PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviation: PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2′-bipyridine-6,6′-diyl)] (abbreviation: PF-BPy) can also be used as the electron transport material.

[0289] The electron transport layer (114, 114a, 114b) may have not only a single layer structure but also a structure in which two or more layers made of the above-mentioned substances are stacked.

[0290] <Electron injection layer> The electron injection layer (115, 115a, 115b) is a layer containing a substance with high electron injection properties. The electron injection layer (115, 115a, 115b) is a layer for increasing the efficiency of electron injection from the second electrode 102, and it is preferable to use a material having a small difference (0.5 eV or less) between the work function value of the material used for the second electrode 102 and the LUMO level value of the material used for the electron injection layer (115, 115a, 115b). Therefore, the electron injection layer 115 is preferably made of lithium, cesium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF ２ ), 8-(quinolinolato)lithium (abbreviation: Liq), 2-(2-pyridyl)phenolatolithium (abbreviation: LiPP), 2-(2-pyridyl)-3-pyridinolatolithium (abbreviation: LiPPy), 4-phenyl-2-(2-pyridyl)phenolatolithium (abbreviation: LiPPP), lithium oxide (LiO ｘ), alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. Also, erbium fluoride (ErF ３ A rare earth metal compound such as ytterbium (Yb) or ytterbium (Yb) can be used. The electron injection layer (115, 115a, 115b) may be formed by mixing a plurality of the above materials, or by stacking a plurality of the above materials. The electron injection layer (115, 115a, 115b) may also be formed by using an electride. Examples of the electride include a substance in which a high concentration of electrons is added to a mixed oxide of calcium and aluminum. The substances constituting the above-mentioned electron transport layer (114, 114a, 114b) can also be used.

[0291] The electron injection layer (115, 115a, 115b) may also be formed using a mixed material comprising an organic compound and an electron donor (donor). Such a mixed material has excellent electron injection and electron transport properties because electrons are generated in the organic compound by the electron donor. In this case, the organic compound is preferably a material that is excellent at transporting the generated electrons. Specifically, the electron transport materials (metal complexes, heteroaromatic compounds, etc.) used in the electron transport layer (114, 114a, 114b) described above can be used. The electron donor may be any substance that exhibits electron donating properties to the organic compound. Specifically, alkali metals, alkaline earth metals, or rare earth metals are preferred, such as lithium, 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. Furthermore, a plurality of these materials may be laminated.

[0292] Alternatively, the electron injection layer (115, 115a, 115b) may be made of a mixed material obtained by mixing an organic compound and a metal. The organic compound used here preferably has a LUMO (Lowest Unoccupied Molecular Orbital) level of −3.6 eV or more and −2.3 eV or less. A material having an unshared electron pair is also preferred.

[0293] Therefore, the organic compound used in the mixed material may be a mixed material obtained by mixing a heteroaromatic compound with a metal, as described above as being usable in the electron transport layer. Preferred heteroaromatic compounds include heteroaromatic compounds having a five-membered ring structure (such as an imidazole ring, a triazole ring, an oxazole ring, an oxadiazole ring, a thiazole ring, or a benzimidazole ring), heteroaromatic compounds having a six-membered ring structure (such as a pyridine ring, a diazine ring (including a pyrimidine ring, a pyrazine ring, or a pyridazine ring), a triazine ring, a bipyridine ring, or a terpyridine ring), and heteroaromatic compounds having a fused ring structure partially including a six-membered ring structure (such as a quinoline ring, a benzoquinoline ring, a quinoxaline ring, a dibenzoquinoxaline ring, or a phenanthroline ring). Specific materials are described above, and therefore will not be described here.

[0294] As the metal used in the mixed material, it is preferable to use a transition metal belonging to Group 5, 7, 9 or 11 in the periodic table, or a material belonging to Group 13, such as Ag, Cu, Al or In. In this case, the organic compound forms a Singly Occupied Molecular Orbital (SOMO) with the transition metal.

[0295] For example, when light obtained from the light-emitting layer 113b is to be amplified, the optical distance between the second electrode 102 and the light-emitting layer 113b is preferably less than ¼ of the wavelength λ of light emitted by the light-emitting layer 113b. In this case, the optical distance can be adjusted by changing the film thickness of the electron-transporting layer 114b or the electron-injecting layer 115b.

[0296] Furthermore, as in the light-emitting device shown in FIG. 5D, by providing a charge generation layer 106 between two EL layers (103 a, 103 b), a structure in which multiple EL layers are stacked between a pair of electrodes (also called a tandem structure) can be formed.

[0297] <Charge Generation Layer> The charge generation layer 106 has a function of injecting electrons into the EL layer 103a and injecting holes into the EL layer 103b when a voltage is applied between the first electrode (anode) 101 and the second electrode (cathode) 102. The charge generation layer 106 may have a structure in which an electron acceptor is added to a hole transporting material, or a structure in which an electron donor is added to an electron transporting material. Alternatively, both of these structures may be stacked. By forming the charge generation layer 106 using the above-described materials, it is possible to suppress an increase in driving voltage when EL layers are stacked.

[0298] In the case where the charge generation layer 106 has a structure in which an electron acceptor is added to a hole-transporting material that is an organic compound, the material described in this embodiment mode can be used as the hole-transporting material. ４ -TCNQ), chloranil, etc. Also included are oxides of metals belonging to Groups 4 to 8 of the periodic table. Specific examples include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide.

[0299] When the charge generation layer 106 has a structure in which an electron donor is added to an electron transporting material, the materials described in this embodiment can be used as the electron transporting material. 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 of 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, cesium carbonate, or the like can be preferably used. An organic compound such as tetrathianaphthacene can also be used as the electron donor.

[0300] Although FIG. 5D shows a structure in which the EL layer 103 has two stacked layers, a stacked structure of three or more EL layers may be used by providing a charge generating layer between different EL layers.

[0301] <Substrate> The light-emitting device described in this embodiment can be formed on various substrates. Note that the type of substrate is not limited to a specific one. Examples of the substrate include a semiconductor substrate (for example, a single crystal substrate or a silicon substrate), an SOI substrate, a glass substrate, a quartz substrate, a plastic substrate, a metal substrate, a stainless steel substrate, a substrate having stainless steel foil, a tungsten substrate, a substrate having tungsten foil, a flexible substrate, a laminated film, paper containing a fibrous material, or a base film.

[0302] Examples of glass substrates include barium borosilicate glass, aluminoborosilicate glass, soda lime glass, etc. Examples of flexible substrates, laminated films, base films, etc. include plastics such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyethersulfone (PES), synthetic resins such as acrylic, polypropylene, polyester, polyvinyl fluoride, polyvinyl chloride, polyamide, polyimide, aramid, epoxy resins, inorganic vapor deposition films, and papers.

[0303] Note that a gas phase method such as vapor deposition, or a liquid phase method such as spin coating or inkjet printing can be used to fabricate the light-emitting device described in this embodiment. When a vapor deposition method is used, a physical vapor deposition (PVD) method such as sputtering, ion plating, ion beam deposition, molecular beam deposition, or vacuum deposition, or a chemical vapor deposition (CVD) method can be used. In particular, layers having various functions included in the EL layer of the light-emitting device (hole injection layer 111, hole transport layer 112, light-emitting layer 113, electron transport layer 114, and electron injection layer 115) can be formed by a vapor deposition method (vacuum deposition, etc.), a coating method (dip coating, die coating, bar coating, spin coating, spray coating, etc.), a printing method (inkjet printing, screen (stencil printing), offset (lithographic printing), flexography (relief printing), gravure printing, microcontact printing, etc.), or the like.

[0304] When applying a film formation method such as the coating method or printing method, it is possible to use high molecular weight compounds (oligomers, dendrimers, polymers, etc.), medium molecular weight compounds (compounds in the intermediate range between low molecular weight and high molecular weight: molecular weight of 400 to 4000), inorganic compounds (quantum dot materials, etc.), etc. As the quantum dot material, it is possible to use colloidal quantum dot materials, alloy type quantum dot materials, core-shell type quantum dot materials, core type quantum dot materials, etc.

[0305] The materials for the layers (hole injection layer 111, hole transport layer 112, light-emitting layer 113, electron transport layer 114, and electron injection layer 115) constituting the EL layer 103 of the light-emitting device described in this embodiment mode are not limited to those described in this embodiment mode, and other materials can be used in combination as long as they can fulfill the functions of the respective layers.

[0306] In this specification and the like, the terms "layer" and "film" can be used interchangeably as appropriate.

[0307] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0308] Embodiment 3 In this embodiment, a specific configuration example of a light-emitting and receiving device according to one embodiment of the present invention and an example of a manufacturing method thereof will be described.

[0309] <Configuration Example of Light-Emitting and Receiving Device 700> The light-emitting and receiving device 700 shown in FIG. 6A includes a light-emitting device 550B, a light-emitting device 550G, a light-emitting device 550R, and a light-receiving device 550PS. The light-emitting device 550B, the light-emitting device 550G, the light-emitting device 550R, and the light-receiving device 550PS are formed on a functional layer 520 provided on a first substrate 510. The functional layer 520 includes circuits such as a driving circuit GD composed of multiple transistors, as well as wiring and the like that electrically connects these devices. These driving circuits are, for example, electrically connected to and can drive the light-emitting device 550B, the light-emitting device 550G, the light-emitting device 550R, and the light-receiving device 550PS. The light-emitting and receiving device 700 also includes an insulating layer 705 on the functional layer 520 and each device (the light-emitting device and the light-receiving device). The insulating layer 705 functions to bond the second substrate 770 and the functional layer 520 together.

[0310] Note that light-emitting device 550B, light-emitting device 550G, light-emitting device 550R, and light-receiving device 550PS have the device structures described in Embodiment 1 and Embodiment 2. Note that in this embodiment, a case will be described in which each device (plurality of light-emitting devices and light-receiving devices) can be formed separately; however, one embodiment of the present invention is not limited thereto.

[0311] In this specification and the like, a structure in which the light-emitting layers of the light-emitting devices of each color (e.g., blue (B), green (G), and red (R)) and the light-receiving layers of the light-receiving devices are separately fabricated or separately painted may be referred to as an SBS (Side By Side) structure. In the light-receiving and light-emitting device 700 shown in FIG. 6A , the light-emitting device 550B, the light-emitting device 550G, the light-emitting device 550R, and the light-receiving device 550PS are arranged in this order, but one embodiment of the present invention is not limited to this configuration. For example, in the light-receiving and light-emitting device 700, these devices may be arranged in the order of the light-emitting device 550R, the light-emitting device 550G, the light-emitting device 550B, and the light-receiving device 550PS.

[0312] In FIG. 6A , light-emitting device 550B has electrodes 551B, 552, and EL layer 103B. Light-emitting device 550G has electrodes 551G, 552, and EL layer 103G. Light-emitting device 550R has electrodes 551R, 552, and EL layer 103R. Light-receiving device 550PS has electrodes 551PS, 552, and light-receiving layer 103PS. The specific configurations of each layer of the light-emitting device are as described in embodiment 2. EL layers 103B, 103G, and 103R have a stacked structure consisting of multiple layers with different functions, including light-emitting layers (105B, 105G, and 105R). The specific configurations of each layer of the light-receiving device are as described in embodiment 1. Light-receiving layer 103PS has a stacked structure consisting of multiple layers with different functions, including active layer 105PS. 6A illustrates the case where the EL layer 103B has a hole injection / transport layer 104B, a light-emitting layer 105B, an electron transport layer 108B, and an electron injection layer 109; the EL layer 103G has a hole injection / transport layer 104G, a light-emitting layer 105G, an electron transport layer 108G, and an electron injection layer 109; the EL layer 103R has a hole injection / transport layer 104R, a light-emitting layer 105R, an electron transport layer 108R, and an electron injection layer 109; and the light-receiving layer 103PS has a first transport layer 104PS, an active layer 105PS, a second transport layer 108PS, and an electron injection layer 109; however, the present invention is not limited to this. The hole injection / transport layers (104B, 104G, 104R) are layers having the functions of the hole injection layer and the hole transport layer shown in Embodiment 2, and may have a laminated structure.

[0313] The electron transport layers (108B, 108G, and 108R) and the second transport layer 108PS may have a function of blocking holes that move from the anode side through the EL layers (103B, 103G, and 103R) and the light-receiving layer 103PS to the cathode side. The electron injection layer 109 may have a laminated structure formed of partially or entirely different materials.

[0314] 6A , an insulating layer 107 may be formed on the side surfaces (or edges) of the hole injection / transport layers (104B, 104G, 104R), the light-emitting layers (105B, 105G, 105R), and the electron transport layers (108B, 108G, 108R) of the EL layers (103B, 103G, 103R), and on the side surfaces (or edges) of the first transport layer 104PS, the active layer 105PS, and the second transport layer 108PS of the light-receiving layer 103PS. The insulating layer 107 is formed in contact with the side surfaces (or edges) of the EL layers (103B, 103G, 103R) and the light-receiving layer 103PS. This prevents oxygen, moisture, or their constituent elements from penetrating into the EL layers (103B, 103G, 103R) and the light-receiving layer 103PS from their side surfaces. The insulating layer 107 can be formed using, for example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, or silicon nitride oxide. The insulating layer 107 may also be formed by stacking the above-mentioned materials. The insulating layer 107 can be formed by sputtering, CVD, MBE, PLD, ALD, or other methods, but ALD is preferred due to its excellent coverage. The insulating layer 107 has a structure that continuously covers part of the EL layers (103B, 103G, and 103R) of adjacent light-emitting devices or part of the side surfaces (or ends) of the light-receiving layer 103PS of the light-receiving device. For example, in FIG. 6A , part of the EL layer 103G of the light-emitting device 550B and part of the side surfaces of the EL layer 103G of the light-emitting device 550G are covered by the insulating layer 107. In addition, it is preferable that a partition wall 528 made of an insulating material be formed in the region covered with the insulating layer 107 as shown in FIG. 6A.

[0315] An electron injection layer 109 is formed on the electron transport layers (108B, 108G, 108R) that are part of the EL layers (103B, 103G, 103R), the second transport layer 108PS that is part of the light-receiving layer 103PS, and the insulating layer 107. The electron injection layer 109 may have a stacked structure of two or more layers (for example, a stack of layers with different electrical resistances).

[0316] The electrode 552 is formed on the electron injection layer 109. The electrodes (551B, 551G, 551R) and the electrode 552 overlap each other in some areas. The light-emitting layer 105B is located between the electrode 551B and the electrode 552, the light-emitting layer 105G is located between the electrode 551G and the electrode 552, the light-emitting layer 105R is located between the electrode 551R and the electrode 552, and the light-receiving layer 103PS is located between the electrode 551PS and the electrode 552.

[0317] 6A (103B, 103G, 103R) have the same configuration as the EL layer 103 described in Embodiment 2. The light-receiving layer 103PS has the same configuration as the light-receiving layer 203 described in Embodiment 1. For example, the light-emitting layer 105B can emit blue light, the light-emitting layer 105G can emit green light, and the light-emitting layer 105R can emit red light.

[0318] A partition wall 528 is provided in a region surrounded by the electron injection layer 109 and the insulating layers (107B, 107G, 107R, 107PS). As shown in Fig. 6A , the electrodes (551B, 551G, 551R, 551PS) of each light-emitting device, parts of the EL layers (103B, 103G, 103R), and parts of the light-receiving layer 103PS are in contact with the partition wall 528 at their sides (or ends) via the insulating layer 107.

[0319] In each EL layer and light-receiving layer, the hole injection layer included in the hole transport region located between the anode and the light-emitting layer and between the anode and the active layer often has high conductivity, and therefore, if it is formed as a layer common to adjacent devices, it may cause crosstalk. Therefore, by providing a partition wall 528 made of an insulating material between each EL layer and light-receiving layer as shown in this configuration example, it is possible to suppress the occurrence of crosstalk between adjacent devices.

[0320] Furthermore, in the manufacturing method described in this embodiment, the side surfaces (or edges) of the EL layer and the light-receiving layer are exposed during the patterning process. Therefore, the EL layer and the light-receiving layer are likely to deteriorate due to the intrusion of oxygen, water, and the like from the side surfaces (or edges) of the EL layer and the light-receiving layer. Therefore, by providing the partition 528, it is possible to suppress the deterioration of the EL layer and the light-receiving layer during the manufacturing process.

[0321] Furthermore, providing the partition 528 can also flatten recesses formed between adjacent devices. Flattening the recesses can prevent disconnection of the electrodes 552 formed on each EL layer and light-receiving layer. Examples of insulating materials used to form the partition 528 include organic materials such as acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimideamide resin, silicone resin, siloxane resin, benzocyclobutene-based resin, phenolic resin, and precursors of these resins. Organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, and alcohol-soluble polyamide resin may also be used. Photosensitive resins such as photoresists can also be used. The photosensitive resin can be a positive-type material or a negative-type material.

[0322] By using a photosensitive resin, the partition wall 528 can be formed only by exposure and development processes. Alternatively, the partition wall 528 may be formed using a negative photosensitive resin (e.g., a resist material). When an insulating layer containing an organic material is used for the partition wall 528, it is preferable to use a material that absorbs visible light. Using a material that absorbs visible light for the partition wall 528 allows the partition wall 528 to absorb light emitted from the EL layer, thereby suppressing light (stray light) that may leak into the adjacent EL layer and light-receiving layer. Therefore, a display panel with high display quality can be provided.

[0323] The difference in height between the upper surface of the partition wall 528 and the upper surface of any one of the EL layer 103B, the EL layer 103G, the EL layer 103R, and the light-receiving layer 103PS is, for example, preferably 0.5 times or less, more preferably 0.3 times or less, the thickness of the partition wall 528. For example, the partition wall 528 may be provided so that the upper surface of any one of the EL layer 103B, the EL layer 103G, the EL layer 103R, and the light-receiving layer 103PS is higher than the upper surface of the partition wall 528. For example, the partition wall 528 may be provided so that the upper surface of the partition wall 528 is higher than the upper surfaces of the EL layer 103B, the EL layer 103G, the EL layer 103R, and the light-receiving layer 103PS.

[0324] In a high-resolution light-receiving and light-emitting device (display panel) having a resolution of more than 1000 ppi, if electrical conduction is found between the EL layer 103B, the EL layer 103G, the EL layer 103R, and the light-receiving layer 103PS, crosstalk occurs, narrowing the color gamut that can be displayed by the light-receiving and light-emitting device. By providing the partition 528 in a high-resolution display panel having a resolution of more than 1000 ppi, preferably a high-resolution display panel having a resolution of more than 2000 ppi, and more preferably an ultra-high-resolution display panel having a resolution of more than 5000 ppi, a display panel that can display vivid colors can be provided.

[0325] 6B and 6C are schematic top views of the light emitting and receiving device 700 corresponding to the dashed line Ya-Yb in the cross-sectional view of FIG. 6A. That is, the light emitting devices 550B, 550G, and 550R are arranged in a matrix. FIG. 6B shows a so-called stripe arrangement in which light emitting devices of the same color are arranged in the Y direction. FIG. 6C shows a configuration in which light emitting devices of the same color are arranged in the Y direction, but with a pattern formed for each pixel. The arrangement of the light emitting devices is not limited to this, and other arrangements such as a delta arrangement or a zigzag arrangement may also be used. Alternatively, a pentile arrangement or a diamond arrangement may also be used.

[0326] In addition, since pattern formation is performed by photolithography in the separation process of each EL layer (103B, 103G, 103R) and the light-receiving layer 103PS, a high-resolution light-receiving and light-emitting device (display panel) can be manufactured. Furthermore, the ends (side surfaces) of each layer of the EL layer processed by pattern formation by photolithography have a shape that is approximately the same surface (or located on approximately the same plane). Furthermore, the side surfaces (end surfaces) of each layer of the light-receiving layer processed by pattern formation by photolithography have a shape that is approximately the same surface (or located on approximately the same plane). Furthermore, in this case, the width (SE) of the gap 580 between each EL layer and the light-receiving layer is preferably 5 μm or less, and more preferably 1 μm or less.

[0327] In the EL layer, the hole injection layer included in the hole transport region located between the anode and the light-emitting layer often has high conductivity, and therefore, if it is formed as a layer common to adjacent light-emitting devices, it may cause crosstalk. Therefore, by separating the EL layer by pattern formation using photolithography as shown in this configuration example, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0328] 6B and 6C. Fig. 6D shows a connection portion 130 where the connection electrode 551C and the electrode 552 are electrically connected. In the connection portion 130, the electrode 552 is provided in contact with the connection electrode 551C. A partition wall 528 is provided to cover the end of the connection electrode 551C.

[0329] 7A, an electrode 551B, an electrode 551G, an electrode 551R, and an electrode 551PS are formed. For example, a conductive film is formed on the functional layer 520 formed on the first substrate 510, and processed into a predetermined shape by photolithography.

[0330] The conductive film can be formed by sputtering, chemical vapor deposition (CVD), molecular beam epitaxy (MBE), vacuum evaporation, pulsed laser deposition (PLD), atomic layer deposition (ALD), or the like. CVD methods include plasma enhanced chemical vapor deposition (PECVD) and thermal CVD. One type of thermal CVD method is metal organic chemical vapor deposition (MOCVD).

[0331] In addition to the photolithography method described above, the conductive film may be processed by a nanoimprint method, a sandblasting method, a lift-off method, etc. Alternatively, an island-shaped thin film may be directly formed by a film formation method using a shielding mask such as a metal mask.

[0332] There are two typical photolithography methods. One is a method in which a resist mask is formed on a thin film to be processed, the thin film is processed by etching or the like, and the resist mask is then removed. The other is a method in which a photosensitive thin film is formed, and then the thin film is processed into a desired shape by exposure and development. Note that the former method includes heat treatment steps such as pre-applied bake (PAB) after resist application and post-exposure bake (PEB) after exposure. In one embodiment of the present invention, lithography is used not only for processing a conductive film but also for processing a thin film (a film made of an organic compound or a film partially containing an organic compound) used to form an EL layer.

[0333] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these. Other light sources that can be used include ultraviolet light, KrF laser light, ArF laser light, etc. Exposure can also be performed by immersion exposure technology. Extreme ultraviolet (EUV) light or X-rays can also be used as the light used for exposure. An electron beam can also be used instead of light used for exposure. Extreme ultraviolet light, X-rays, or an electron beam are preferred because they enable extremely fine processing. When exposure is performed by scanning a beam such as an electron beam, a photomask is not required.

[0334] For etching the thin film using a resist mask, dry etching, wet etching, sandblasting, or the like can be used.

[0335] Next, as shown in FIG. 7B , a hole injection / transport layer 104B, a light-emitting layer 105B, and an electron transport layer 108B are formed on the electrode 551B, the electrode 551G, the electrode 551R, and the electrode 551PS. The hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B can be formed by, for example, vacuum evaporation. Furthermore, a sacrificial layer 110B is formed on the electron transport layer 108B. The materials described in Embodiment 2 can be used to form the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B.

[0336] The sacrificial layer 110B is preferably a film that is highly resistant to the etching processes of the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B, i.e., a film with a large etching selectivity. The sacrificial layer 110B preferably has a stacked structure of a first sacrificial layer and a second sacrificial layer that have different etching selectivity. The sacrificial layer 110B can be a film that can be removed by wet etching, which causes minimal damage to the EL layer 103B. Oxalic acid or the like can be used as an etching material for wet etching.

[0337] The sacrificial layer 110B may be, for example, a metal film, an alloy film, a metal oxide film, a semiconductor film, an inorganic insulating film, etc. The sacrificial layer 110B may be formed by various film formation methods such as a sputtering method, a vapor deposition method, a CVD method, an ALD method, etc.

[0338] The sacrificial layer 110B may be made of a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, or tantalum, or an alloy material containing such a metal material. In particular, it is preferable to use a low-melting-point material such as aluminum or silver.

[0339] The sacrificial layer 110B may be made of a metal oxide such as indium gallium zinc oxide (In-Ga-Zn oxide, also referred to as IGZO). Other examples include indium oxide, indium zinc oxide (In-Zn oxide), indium tin oxide (In-Sn oxide), indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), and indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide). Alternatively, silicon-containing indium tin oxide may be used.

[0340] The present invention can also be applied to a case where, instead of the gallium, an element M (wherein M is one or more elements selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) is used. In particular, it is preferable that M is one or more elements selected from gallium, aluminum, and yttrium.

[0341] The sacrificial layer 110B may be made of an inorganic insulating material such as aluminum oxide, hafnium oxide, or silicon oxide.

[0342] Furthermore, it is preferable to use a material for the sacrificial layer 110B that is soluble in a chemically stable solvent, at least for the uppermost electron transport layer 108B. In particular, a material that dissolves in water or alcohol is suitable for use in the sacrificial layer 110B. When forming the sacrificial layer 110B, it is preferable to apply the sacrificial layer 110B dissolved in a solvent such as water or alcohol using a wet film formation method, and then perform a heat treatment to evaporate the solvent. In this case, performing the heat treatment under a reduced pressure atmosphere is preferable because it allows the solvent to be removed at a low temperature and in a short time, thereby reducing thermal damage to the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B.

[0343] When the sacrificial layer 110B has a laminated structure, a layer made of the above-mentioned material can be used as a first sacrificial layer, and a second sacrificial layer can be formed thereon to form a laminated structure.

[0344] In this case, the second sacrificial layer is a film used as a hard mask when etching the first sacrificial layer. Furthermore, the first sacrificial layer is exposed when the second sacrificial layer is processed. Therefore, a combination of films with a high etching selectivity is selected for the first sacrificial layer and the second sacrificial layer. Therefore, a film that can be used for the second sacrificial layer can be selected depending on the etching conditions for the first sacrificial layer and the second sacrificial layer.

[0345] For example, when dry etching using a gas containing fluorine (also called a fluorine-based gas) is used to etch the second sacrificial layer, silicon, silicon nitride, silicon oxide, tungsten, titanium, molybdenum, tantalum, tantalum nitride, an alloy containing molybdenum and niobium, an alloy containing molybdenum and tungsten, etc. can be used for the second sacrificial layer. Here, metal oxide films such as IGZO and ITO can be used as films that can have a large etching selectivity (i.e., can slow the etching rate) compared to dry etching using the fluorine-based gas, and these can be used for the first sacrificial layer.

[0346] However, the second sacrificial layer is not limited to this, and can be selected from various materials depending on the etching conditions of the first sacrificial layer and the second sacrificial layer, for example, from among the films that can be used for the first sacrificial layer.

[0347] The second sacrificial layer may be, for example, a nitride film, such as silicon nitride, aluminum nitride, hafnium nitride, titanium nitride, tantalum nitride, tungsten nitride, gallium nitride, or germanium nitride.

[0348] Alternatively, an oxide film can be used as the second sacrificial layer. Typically, an oxide film or an oxynitride film such as silicon oxide, silicon oxynitride, aluminum oxide, aluminum oxynitride, hafnium oxide, or hafnium oxynitride can be used.

[0349] Next, as shown in FIG. 7C , resist is applied to the sacrificial layer 110B, and the resist is formed into a desired shape (resist mask: REG) using photolithography. When performing this method, heat treatment processes such as pre-applied bake (PAB) after resist application and post-exposure bake (PEB) after exposure are also performed. For example, the PAB temperature is approximately 100° C., and the PEB temperature is approximately 120° C. Therefore, the light-emitting device must be able to withstand these processing temperatures.

[0350] Next, using the obtained resist mask REG, a portion of the sacrificial layer 110B that is not covered by the resist mask REG is removed by etching. After the resist mask REG is removed, a portion of the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B that is not covered by the sacrificial layer 110B is removed by etching, and the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B are processed into a shape that has a side surface on the electrode 551B (or has an exposed side surface) or into a strip-like shape extending in a direction intersecting with the plane of the page. Dry etching is preferred for this etching. When the sacrificial layer 110B has a laminated structure of the first and second sacrificial layers, a portion of the second sacrificial layer may be etched using the resist mask REG, and then the resist mask REG may be removed. Then, a portion of the first sacrificial layer may be etched using the second sacrificial layer as a mask, thereby processing the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B into the predetermined shapes. These etching processes result in the shape shown in FIG. 8A .

[0351] 8B , a hole injection / transport layer 104G, a light-emitting layer 105G, and an electron transport layer 108G are formed on the sacrificial layer 110B, the electrode 551G, the electrode 551R, and the electrode 551PS. The materials used to form the hole injection / transport layer 104G, the light-emitting layer 105G, and the electron transport layer 108G can be the same as those described in Embodiment 2. The hole injection / transport layer 104G, the light-emitting layer 105G, and the electron transport layer 108G can be formed by vacuum evaporation, for example.

[0352] 8C , a sacrificial layer 110G is formed on the electron transport layer 108G, a resist is applied to the sacrificial layer 110G, and the resist is formed into a desired shape (resist mask: REG) using photolithography. The portion of the sacrificial layer 110G that is not covered by the resulting resist mask REG is then removed by etching. After the resist mask REG is removed, the portions of the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108G that are not covered by the sacrificial layer 110G are then removed by etching. This allows the hole injection / transport layer 104G, the light-emitting layer 105G, and the electron transport layer 108G to be shaped so that they have sides (or have exposed sides) on the electrode 551G or strip-like shapes extending in a direction intersecting the plane of the page. Dry etching is preferred for this etching. Furthermore, the sacrificial layer 110G can be made of the same material as the sacrificial layer 110B. When the sacrificial layer 110G has a laminated structure of the first and second sacrificial layers, a portion of the second sacrificial layer may be etched using a resist mask REG, and then the resist mask REG may be removed. Then, a portion of the first sacrificial layer may be etched using the second sacrificial layer as a mask, thereby processing the hole injection / transport layer 104G, the light-emitting layer 105G, and the electron transport layer 108G into the predetermined shapes. These etching processes result in the shape shown in FIG. 9A .

[0353] 9B , a hole injection / transport layer 104R, a light-emitting layer 105R, and an electron transport layer 108R are formed on the sacrificial layer 110B, the sacrificial layer 110G, the electrode 551R, and the electrode 551PS. The materials used to form the hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R can be the same as those described in Embodiment 2. The hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R can be formed by vacuum deposition, for example.

[0354] 9C , a sacrificial layer 110R is formed on the electron transport layer 108R, a resist is applied to the sacrificial layer 110R, and the resist is formed into a desired shape (resist mask: REG) using photolithography. The portion of the sacrificial layer 110R that is not covered by the resulting resist mask REG is then removed by etching. After the resist mask REG is removed, the portions of the hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R that are not covered by the sacrificial layer are then removed by etching. This allows the hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R to be shaped so that they have sides (or have exposed sides) on the electrode 551R or strip-like shapes extending in a direction intersecting the plane of the page. Dry etching is preferred for this etching. The sacrificial layer 110R can be made of the same material as the sacrificial layer 110B. When the sacrificial layer 110R has a laminated structure of the first and second sacrificial layers, the second sacrificial layer may be partially etched using a resist mask REG, and then the resist mask REG may be removed. Then, the first sacrificial layer may be partially etched using the second sacrificial layer as a mask, thereby processing the hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R into the predetermined shapes. These etching processes result in the shape shown in FIG. 10A .

[0355] 10B , a first transport layer 104PS, an active layer 105PS, and a second transport layer 108PS are formed on the sacrificial layers 110B, 110G, and 110R, and the electrode 551PS. The materials used to form the first transport layer 104PS, the active layer 105PS, and the second transport layer 108PS can be the same as those described in Embodiment 1. The first transport layer 104PS, the active layer 105PS, and the second transport layer 108PS can be formed by vacuum deposition, for example.

[0356] 10C , a sacrificial layer 110PS is formed on the second transport layer 108PS, a resist is applied to the sacrificial layer 110PS, and the resist is formed into a desired shape (resist mask: REG) using photolithography. The portion of the sacrificial layer 110PS that is not covered by the resulting resist mask REG is removed by etching. After the resist mask REG is removed, the portions of the first transport layer 104PS, the active layer 105PS, and the second transport layer 108PS that are not covered by the sacrificial layer are removed by etching. This allows the first transport layer 104PS, the active layer 105PS, and the second transport layer 108PS to be shaped so that they have sides (or have exposed sides) on the electrode 551PS or strip-like shapes extending in a direction intersecting the plane of the page. Dry etching is preferred for this etching. Furthermore, the sacrificial layer 110PS can be made of the same material as the sacrificial layer 110B. When the sacrificial layer 110PS has a laminated structure of the first and second sacrificial layers, a portion of the second sacrificial layer may be etched using a resist mask REG, and then the resist mask REG may be removed. Then, a portion of the first sacrificial layer may be etched using the second sacrificial layer as a mask, and the first transport layer 104PS, the active layer 105PS, and the second transport layer 108PS may be processed into the predetermined shapes. These etching processes result in the shape shown in FIG. 10D.

[0357] Next, as shown in FIG. 11A, an insulating layer 107 is formed on the sacrificial layers 110B, 110G, 110R, and 110PS.

[0358] The insulating layer 107 can be formed by, for example, ALD. In this case, as shown in FIG. 11A , the insulating layer 107 is formed in contact with the side surfaces (ends) of the hole injection / transport layers (104B, 104G, 104R), light-emitting layers (105B, 105G, 105R), and electron transport layers (108B, 108G, 108R) of the light-emitting devices, as well as the first transport layer 104PS, active layer 105PS, and second transport layer 108PS of the light-receiving device. This prevents oxygen, moisture, or their constituent elements from penetrating into the interior from the side surfaces. Examples of materials that can be used for the insulating layer 107 include aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, and silicon nitride oxide.

[0359] 11B , after removing the sacrificial layers (110B, 110G, 110R, and 110PS), an electron injection layer 109 is formed on the insulating layer 107, the electron transport layers (108B, 108G, and 108R), and the second transport layer 108PS. Note that the insulating layer 107 is formed by removing a part of the insulating layer 107 simultaneously with removing the sacrificial layers (110B, 110G, 110R, and 110PS). The electron injection layer 109 can be formed using the materials described in Embodiment 2. Note that the electron injection layer 109 is formed by, for example, vacuum evaporation. The electron injection layer 109 has a structure in which it contacts, via the insulating layer 107, the hole injection / transport layers (104B, 104G, 104R), the light-emitting layers (105B, 105G, 105R), and the electron transport layers (108B, 108G, 108R) of the light-emitting devices, as well as the first transport layer 104PS, the active layer 105PS, and the second transport layer 108PS of the light-receiving device on their respective side surfaces (ends).

[0360] 11C , an electrode 552 is formed. The electrode 552 is formed by, for example, vacuum deposition. The electrode 552 is formed on the electron injection layer 109. The electrode 552 is structured to be in contact with the hole injection / transport layers (104B, 104G, 104R), light-emitting layers (105B, 105G, 105R), and electron transport layers (108B, 108G, 108R) of the light-emitting devices, and with the side surfaces (ends) of the first transport layer 104PS, active layer 105PS, and second transport layer 108PS of the light-receiving device, via the electron injection layer 109 and the insulating layer 107. This makes it possible to prevent electrical short-circuiting between the hole injection / transport layers (104B, 104G, 104R), light-emitting layers (105B, 105G, 105R), and electron transport layers (108B, 108G, 108R) of each light-emitting device, and between the first transport layer 104PS, active layer 105PS, and second transport layer 108PS of the light-receiving device and the electrode 552.

[0361] Through the above steps, EL layers 103B, 103G, 103R, and light-receiving layer 103PS in light-emitting devices 550B, 550G, and 550R, and light-receiving device 550PS can be separated and processed, respectively.

[0362] In addition, since pattern formation is performed by photolithography in the separation processing of these EL layers (103B, 103G, 103R) and the light receiving layer 103PS, a high-definition light receiving and emitting device (display panel) can be manufactured. Furthermore, the ends (side surfaces) of each layer of the EL layer processed by pattern formation by photolithography have a shape that has approximately the same surface (or is located on approximately the same plane). Furthermore, the side surfaces (end surfaces) of each layer of the light receiving layer processed by pattern formation by photolithography have a shape that has approximately the same surface (or is located on approximately the same plane).

[0363] Furthermore, the hole injection / transport layers (104B, 104G, 104R) in these EL layers and the first transport layer 104PS in the light-receiving layer often have high electrical conductivity, which may cause crosstalk if they are formed as layers common to adjacent light-emitting devices. Therefore, by separating each layer through pattern formation by photolithography as shown in this configuration example, it is possible to suppress the occurrence of crosstalk between adjacent devices.

[0364] In addition, the hole injection / transport layers (104B, 104G, 104R), light-emitting layers (105B, 105G, 105R), and electron transport layers (108B, 108G, 108R) included in each EL layer (103B, 103G, 103R) of each light-emitting device in this configuration, and the first transport layer 104PS, active layer 105PS, and second transport layer 108PS included in the light-receiving layer 103PS of the light-receiving device are patterned by photolithography during separation processing, so that the edges (side surfaces) of each processed layer have substantially the same surface (or are located on substantially the same plane). Furthermore, the edges (side surfaces) of each layer of the light-receiving layer processed by patterning by photolithography have substantially the same surface (or are located on substantially the same plane).

[0365] Furthermore, the hole injection / transport layers (104B, 104G, 104R), light-emitting layers (105B, 105G, 105R), and electron transport layers (108B, 108G, 108R) included in each EL layer (103B, 103G, 103R) of each light-emitting device, and the first transport layer 104PS, active layer 105PS, and second transport layer 108PS included in the absorption layer 103PS of the light-receiving device are patterned by photolithography during separation processing, so that each processed end (side) has a gap 580 between adjacent light-emitting devices. Note that in Figure 11C, when the distance between the EL layers or absorption layers of adjacent devices is represented by SE, the smaller the distance SE, the higher the aperture ratio and the higher the definition. On the other hand, the larger the distance SE, the more tolerant the influence of manufacturing process variations between adjacent light-emitting devices can be, and therefore the manufacturing yield can be increased. Because the light-emitting devices and light-receiving devices manufactured according to this specification are suitable for miniaturization processes, the distance SE between the EL layers or light-receiving layers of adjacent devices can be set to 0.5 μm or more and 5 μm or less, preferably 1 μm or more and 3 μm or less, more preferably 1 μm or more and 2.5 μm or less, and even more preferably 1 μm or more and 2 μm or less. Typically, the distance SE is preferably 1 μm or more and 2 μm or less (e.g., 1.5 μm or thereabouts).

[0366] In this specification and the like, a device fabricated using a metal mask or an FMM (fine metal mask, high-resolution metal mask) may be referred to as a device with an MM (metal mask) structure. In addition, in this specification and the like, a device fabricated without using a metal mask or an FMM may be referred to as a device with an MML (metal maskless) structure. Because an MML structure light-emitting and receiving device is fabricated without using a metal mask, it has a higher degree of design freedom in terms of pixel arrangement, pixel shape, and the like than an FMM structure light-emitting and receiving device or an MM structure.

[0367] The island-shaped EL layer in the MML-structure light-emitting / receiving device is not formed by a metal mask pattern, but is formed by processing the EL layer after it has been formed. This makes it possible to realize a light-emitting / receiving device with higher resolution or a higher aperture ratio than ever before. Furthermore, since the EL layer can be made separately for each color, a light-emitting / receiving device with extremely vivid, high-contrast, and high display quality can be realized. Furthermore, providing a sacrificial layer on the EL layer reduces damage to the EL layer during the manufacturing process, thereby improving the reliability of the light-emitting device.

[0368] In the light-emitting devices 550B, 550G, and 550R shown in Figures 6A and 11C, the width of the EL layers (103B, 103G, and 103R) is approximately equal to the width of the electrodes (551B, 551G, and 551R), and in the light-receiving device 550PS, the width of the light-receiving layer 103PS is approximately equal to the width of the electrode 551PS, but one embodiment of the present invention is not limited to this.

[0369] In light-emitting devices 550B, 550G, and 550R, the width of the EL layers (103B, 103G, and 103R) may be smaller than the width of the electrodes (551B, 551G, and 551R). In light-receiving device 550PS, the width of light-receiving layer 103PS may be smaller than the width of electrode 551PS. Figure 11D shows an example in which the width of the EL layers (103B and 103G) in light-emitting device 550B and light-emitting device 550G is smaller than the width of the electrodes (551B and 551G).

[0370] In light-emitting devices 550B, 550G, and 550R, the width of the EL layers (103B, 103G, and 103R) may be larger than the width of the electrodes (551B, 551G, and 551R). In light-receiving device 550PS, the width of light-receiving layer 103PS may be larger than the width of electrode 551PS. Figure 11E shows an example in which the width of EL layer 103R is larger than the width of electrode 551R in light-emitting device 550R.

[0371] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0372] 12 to 14. The light-emitting and receiving device 720 shown in FIGS. 12 to 14 is a light-emitting and receiving device having a light-receiving device and a light-emitting device as described in Embodiments 1 and 2. However, the light-emitting and receiving device 720 described in this embodiment can be applied to a display portion of an electronic device or the like, and therefore can also be called a display panel or a display device. The light-emitting and receiving device 720 has a configuration in which a light-emitting device is used as a light source and light from the light-emitting device is received by a light-receiving device.

[0373] The light emitting and receiving device of the present embodiment can be a high-resolution or large-sized light emitting and receiving device, and can therefore be used in electronic devices with 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 in display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, smartphones, wristwatch-type terminals, tablet terminals, personal digital assistants, and sound reproduction devices.

[0374] FIG. 12A shows a top view of the light emitting and receiving device 720. In FIG.

[0375] 12A , the light emitting and receiving device 720 has a configuration in which a substrate 710 and a substrate 711 are bonded together. The light emitting and receiving device 720 also has a display region 701, a circuit 704, wiring 706, and the like. The display region 701 has a plurality of pixels, and a pixel 703(i, j) shown in FIG. 12A has a pixel 703(i+1, j) adjacent to the pixel 703(i, j) as shown in FIG. 12B .

[0376] 12A , an example of the light-emitting and receiving device 720 is shown in which an IC (integrated circuit) 712 is provided on a substrate 710 by a chip-on-glass (COG) method, a chip-on-film (COF) method, or the like. Note that an IC having a scanning line driver circuit or a signal line driver circuit, for example, can be used as the IC 712. In FIG. 12A , an IC having a signal line driver circuit is used as the IC 712, and a scanning line driver circuit is used as the circuit 704.

[0377] The wiring 706 has a function of supplying signals and power to the display region 701 and the circuit 704. The signals and power are input to the wiring 706 from the outside through a flexible printed circuit (FPC) 713 or are input to the wiring 706 from an IC 712. Note that the light-emitting and receiving device 720 may not include an IC. Alternatively, the IC may be mounted on the FPC by a COF method or the like.

[0378] FIG. 12B shows pixel 703(i,j) and pixel 703(i+1,j) in the display region 701. That is, pixel 703(i,j) can be configured to have multiple types of subpixels having light-emitting devices that emit different colors. Alternatively, in addition to the above, pixel 703(i,j) can be configured to include multiple subpixels having light-emitting devices that emit the same color. For example, a pixel can be configured to have three types of subpixels. Examples of the three subpixels include subpixels of three colors: red (R), green (G), and blue (B), or subpixels of three colors: yellow (Y), cyan (C), and magenta (M). Alternatively, a pixel can be configured to have four types of subpixels. Examples of the four subpixels include subpixels of four colors: R, G, B, and white (W), or subpixels of four colors: R, G, B, and Y. Specifically, the pixel 703(i,j) can be configured with a sub-pixel 702B(i,j) that displays blue, a sub-pixel 702G(i,j) that displays green, and a sub-pixel 702R(i,j) that displays red.

[0379] Furthermore, the subpixel may have a configuration including not only a light-emitting device but also a light-receiving device. When the subpixel has a light-receiving device, the light-emitting and receiving device 720 is also referred to as a light-emitting and receiving device.

[0380] 12C to 12F show examples of various layouts including a subpixel 702PS(i,j) having a light receiving device. The pixel arrangement shown in Fig. 12C is a stripe arrangement, while the pixel arrangement shown in Fig. 12D is a matrix arrangement. The pixel arrangement shown in Fig. 12E has a configuration in which three subpixels (subpixel R, subpixel G, and subpixel PS) are vertically arranged next to one subpixel (subpixel B).

[0381] 12F , a subpixel 702IR(i,j) that emits infrared light may be added to the above set to form pixel 703(i,j). The pixel arrangement shown in FIG. 12F has a configuration in which three vertically elongated subpixels G, B, and R are arranged horizontally, and below them, a subpixel PS and a horizontally elongated subpixel IR are arranged horizontally. Specifically, a subpixel 702IR(i,j) that emits light containing light having a wavelength of 650 nm or more and 1000 nm or less may be used for pixel 703(i,j). Although the wavelength of light detected by the subpixel 702PS(i,j) is not particularly limited, it is preferable that the light receiving device of the subpixel 702PS(i,j) is sensitive to light emitted by the light emitting device of the subpixel 702R(i,j), the subpixel 702G(i,j), the subpixel 702G(i,j), or the subpixel 702IR(i,j). For example, it is preferable to detect one or more of light in wavelength ranges such as blue, purple, blue-purple, green, yellow-green, yellow, orange, and red, and light in the infrared wavelength range.

[0382] 12A to 12F, various arrangements of the sub-pixels can be applied, such as a stripe arrangement, an S-stripe arrangement, a matrix arrangement, a delta arrangement, a Bayer arrangement, and a pentile arrangement.

[0383] Examples of the top surface shape of the sub-pixel include a triangle, a quadrangle (including a rectangle and a square), a polygon such as a pentagon, a polygon with rounded corners, an ellipse, a circle, etc. The top surface shape of the sub-pixel here corresponds to the top surface shape of the light-emitting region of the light-emitting device.

[0384] Furthermore, when a pixel has not only a light-emitting device but also a light-receiving device, the pixel has a light-receiving function, so that it is possible to detect contact or proximity of an object while displaying an image. For example, instead of displaying an image using all of the sub-pixels of the light-emitting device, some of the sub-pixels can emit light as a light source and the remaining sub-pixels can display an image.

[0385] It is preferable that the light-receiving area of ​​the subpixel 702PS(i,j) be smaller than the light-emitting area of ​​the other subpixels. The smaller the light-receiving area, the narrower the imaging range, which makes it possible to suppress blurring in the imaging result and improve resolution. Therefore, by using the subpixel 702PS(i,j), high-definition or high-resolution imaging can be performed. For example, the subpixel 702PS(i,j) can be used to capture images for personal authentication using fingerprints, palm prints, irises, pulse shapes (including vein shapes and arterial shapes), faces, etc.

[0386] The subpixel 702PS(i,j) can be used as a touch sensor (also called a direct touch sensor) or a near-touch sensor (also called a hover sensor, hover touch sensor, non-contact sensor, or touchless sensor). For example, the subpixel 702PS(i,j) preferably detects infrared light. This enables touch detection even in dark places.

[0387] Here, a touch sensor or near-touch sensor can detect the proximity or contact of an object (such as a finger, hand, or pen). A touch sensor can detect an object by direct contact between the light-emitting and receiving device and the object. A near-touch sensor can detect an object even if the object does not come into contact with the light-emitting and receiving device. For example, a configuration in which the light-emitting and receiving device can detect an object when the distance between the light-emitting and receiving device and the object is between 0.1 mm and 300 mm, preferably between 3 mm and 50 mm, is preferable. This configuration enables operation without the object directly touching the light-emitting and receiving device, in other words, non-contact (touchless) operation of the light-emitting and receiving device. This configuration reduces the risk of the light-emitting and receiving device becoming dirty or scratched, or enables operation of the light-emitting and receiving device without the object directly touching dirt (e.g., dust, bacteria, or viruses) attached to the light-emitting and receiving device.

[0388] In order to capture high-resolution images, it is preferable that the sub-pixels 702PS(i,j) are provided in all pixels of the light-emitting and receiving device. On the other hand, when used in a touch sensor or near-touch sensor, the sub-pixels 702PS(i,j) do not require high accuracy compared to when capturing images of fingerprints, etc., so they may be provided in only some of the pixels of the light-emitting and receiving device. By making the number of sub-pixels 702PS(i,j) in the light-emitting and receiving device smaller than the number of sub-pixels 702R(i,j), etc., the detection speed can be increased.

[0389] Next, an example of a pixel circuit of a subpixel having a light-emitting device will be described with reference to FIG. 13A. The pixel circuit 530 shown in FIG. 13A includes a light-emitting device (EL) 550, a transistor M15, a transistor M16, a transistor M17, and a capacitor C3. A light-emitting diode can be used as the light-emitting device 550. In particular, it is preferable to use the light-emitting device described in Embodiment 2 as the light-emitting device 550.

[0390] 13A , the gate of the transistor M15 is electrically connected to a wiring VG, one of the source or drain is electrically connected to a wiring VS, and the other of the source or drain is electrically connected to one electrode of the capacitor C3 and the gate of the transistor M16. One of the source or drain of the transistor M16 is electrically connected to a wiring V4, and the other is electrically connected to the anode of the light-emitting device 550 and one of the source or drain of the transistor M17. The gate of the transistor M17 is electrically connected to a wiring MS, and the other of the source or drain is electrically connected to a wiring OUT2. The cathode of the light-emitting device 550 is electrically connected to a wiring V5.

[0391] A constant potential is supplied to the wiring V4 and the wiring V5. The anode side of the light-emitting device 550 can be set to a high potential, and the cathode side can be set to a lower potential than the anode side. The transistor M15 is controlled by a signal supplied to the wiring VG and functions as a selection transistor for controlling the selection state of the pixel circuit 530. The transistor M16 also functions as a drive transistor that controls the current flowing through the light-emitting device 550 depending on the potential supplied to its gate. When the transistor M15 is in a conductive state, the potential supplied to the wiring VS is supplied to the gate of the transistor M16, and the light emission brightness of the light-emitting device 550 can be controlled depending on the potential. The transistor M17 is controlled by a signal supplied to the wiring MS and has the function of outputting the potential between the transistor M16 and the light-emitting device 550 to the outside via the wiring OUT2.

[0392] Note that it is preferable to use transistors using a metal oxide (oxide semiconductor) in a semiconductor layer in which a channel is formed for the transistors M15, M16, and M17 included in the pixel circuit 530 of FIG. 13A and the transistors M11, M12, M13, and M14 included in the pixel circuit 531 of FIG. 13B.

[0393] A transistor using a metal oxide, which has a wider band gap and a lower carrier density than silicon, can achieve an extremely small off-state current. Therefore, the small off-state current allows charge stored in a capacitor connected in series with the transistor to be held for a long period of time. Therefore, it is preferable to use a transistor including an oxide semiconductor for the transistor M11, the transistor M12, and the transistor M15, which are connected in series with the capacitor C2 or the capacitor C3. Furthermore, by using a transistor including an oxide semiconductor for other transistors as well, manufacturing costs can be reduced.

[0394] Alternatively, the transistors M11 to M17 may be transistors in which silicon is used as a semiconductor in which a channel is formed. In particular, using silicon with high crystallinity, such as single crystal silicon or polycrystalline silicon, is preferable because high field-effect mobility can be achieved and higher-speed operation is possible.

[0395] Alternatively, a structure may be used in which at least one of the transistors M11 to M17 includes an oxide semiconductor and the remaining transistors include silicon.

[0396] Next, an example of a pixel circuit of a sub-pixel having a light receiving device will be described with reference to Fig. 13B. The pixel circuit 531 shown in Fig. 13B includes a light receiving device (PD) 560, transistors M11, M12, M13, and M14, and a capacitance element C2. In this example, a photodiode is used as the light receiving device (PD) 560.

[0397] 13B , the anode of the light-receiving device (PD) 560 is electrically connected to the wiring V1, and the cathode is electrically connected to one of the source and drain of the transistor M11. The gate of the transistor M11 is electrically connected to the wiring TX, and the other of the source and drain is electrically connected to one electrode of the capacitor C2, one of the source and drain of the transistor M12, and the gate of the transistor M13. The gate of the transistor M12 is electrically connected to the wiring RES, and the other of the source and drain is electrically connected to the wiring V2. The source and drain of the transistor M13 is electrically connected to the wiring V3, and the other of the source and drain is electrically connected to one of the source and drain of the transistor M14. The gate of the transistor M14 is electrically connected to the wiring SE1, and the other of the source and drain is electrically connected to the wiring OUT1.

[0398] A constant potential is supplied to the wiring V1, the wiring V2, and the wiring V3. When the light-receiving device (PD) 560 is driven with a reverse bias, a potential higher than the potential of the wiring V1 is supplied to the wiring V2. The transistor M12 is controlled by a signal supplied to the wiring RES and has a function of resetting the potential of a node connected to the gate of the transistor M13 to the potential supplied to the wiring V2. The transistor M11 is controlled by a signal supplied to the wiring TX and has a function of controlling the timing at which the potential of the node changes depending on the current flowing through the light-receiving device (PD) 560. The transistor M13 functions as an amplifying transistor that outputs according to the potential of the node. The transistor M14 is controlled by a signal supplied to the wiring SE1 and functions as a selection transistor for reading out an output according to the potential of the node to an external circuit connected to the wiring OUT1.

[0399] Note that although the transistors are shown as n-channel transistors in FIGS. 13A and 13B, p-channel transistors can also be used.

[0400] The transistors included in the pixel circuit 530 and the transistors included in the pixel circuit 531 are preferably formed side by side on the same substrate. In particular, it is preferable that the transistors included in the pixel circuit 530 and the transistors included in the pixel circuit 531 are mixed and periodically arranged in one region.

[0401] It is also preferable to provide one or more layers having one or both of a transistor and a capacitor element at a position overlapping the light receiving device (PD) 560 or the light emitting device (EL) 550. This can reduce the effective area occupied by each pixel circuit, thereby realizing a high-definition light receiving section or display section.

[0402] 13C shows an example of a specific structure of a transistor that can be applied to the pixel circuits described with reference to Fig. 13A and Fig. 13B. Note that a bottom-gate transistor, a top-gate transistor, or the like can be used as the transistor as appropriate.

[0403] 13C includes a semiconductor film 508, a conductive film 504, an insulating film 506, a conductive film 512A, and a conductive film 512B. The transistor is formed over, for example, an insulating film 501C. The transistor also includes an insulating film 516 (insulating films 516A and 516B) and an insulating film 518.

[0404] The semiconductor film 508 has a region 508A electrically connected to the conductive film 512A and a region 508B electrically connected to the conductive film 512B. The semiconductor film 508 has a region 508C between the region 508A and the region 508B.

[0405] The conductive film 504 has a region overlapping with the region 508C, and functions as a gate electrode.

[0406] The insulating film 506 has a region sandwiched between the semiconductor film 508 and the conductive film 504. The insulating film 506 functions as a first gate insulating film.

[0407] The conductive film 512A has a function as either a source electrode or a drain electrode, and the conductive film 512B has the other function as either a source electrode or a drain electrode.

[0408] The conductive film 524 can also be used for a transistor. The conductive film 524 has a region where the semiconductor film 508 is sandwiched between the conductive film 524 and the conductive film 504. The conductive film 524 functions as a second gate electrode. The insulating film 501D is sandwiched between the semiconductor film 508 and the conductive film 524 and functions as a second gate insulating film.

[0409] The insulating film 516 functions as, for example, a protective film that covers the semiconductor film 508. Specific examples of the insulating film 516 that can be used include a silicon oxide film, a silicon oxynitride film, a silicon nitride oxide film, a silicon nitride film, an aluminum oxide film, a hafnium oxide film, an yttrium oxide film, a zirconium oxide film, a gallium oxide film, a tantalum oxide film, a magnesium oxide film, a lanthanum oxide film, a cerium oxide film, and a neodymium oxide film.

[0410] The insulating film 518 is preferably formed using a material that has a function of suppressing diffusion of, for example, oxygen, hydrogen, water, an alkali metal, an alkaline earth metal, or the like. Specifically, for example, silicon nitride, silicon oxynitride, aluminum nitride, aluminum oxynitride, or the like can be used for the insulating film 518. Furthermore, the number of nitrogen atoms contained in silicon oxynitride and aluminum oxynitride is preferably larger than the number of oxygen atoms contained therein.

[0411] Note that a semiconductor film to be used for a transistor in a pixel circuit can be formed in the same process as a semiconductor film to be used for a transistor in a driver circuit. For example, a semiconductor film having the same composition as that of a semiconductor film to be used for a transistor in a pixel circuit can be used for the driver circuit.

[0412] Furthermore, a semiconductor containing an element of Group 14 can be used for the semiconductor film 508. Specifically, a semiconductor containing silicon can be used for the semiconductor film 508.

[0413] Furthermore, hydrogenated amorphous silicon can be used for the semiconductor film 508. Alternatively, microcrystalline silicon or the like can be used for the semiconductor film 508. This makes it possible to provide a device with less display unevenness compared to devices (including light-emitting devices, display panels, display devices, and light-receiving and light-emitting devices) that use polysilicon for the semiconductor film 508. Alternatively, it is easy to increase the size of the device.

[0414] Furthermore, polysilicon can be used for the semiconductor film 508. This allows the field-effect mobility of the transistor to be higher than that of a transistor using hydrogenated amorphous silicon for the semiconductor film 508, for example. Alternatively, the driving capability can be improved compared to that of a transistor using hydrogenated amorphous silicon for the semiconductor film 508, for example. Alternatively, the aperture ratio of a pixel can be improved compared to that of a transistor using hydrogenated amorphous silicon for the semiconductor film 508, for example.

[0415] Alternatively, the reliability of the transistor can be improved compared to a transistor using hydrogenated amorphous silicon for the semiconductor film 508, for example.

[0416] Alternatively, the temperature required to manufacture the transistor can be lower than that of a transistor using single crystal silicon, for example.

[0417] Alternatively, a semiconductor film used for a transistor in a driver circuit can be formed in the same process as a semiconductor film used for a transistor in a pixel circuit. Alternatively, the driver circuit can be formed over the same substrate as the substrate on which the pixel circuit is formed. Alternatively, the number of components constituting an electronic device can be reduced.

[0418] Furthermore, single crystal silicon can be used for the semiconductor film 508. This allows for higher definition than, for example, a light-emitting device (or a display panel) using hydrogenated amorphous silicon for the semiconductor film 508. Alternatively, for example, a light-emitting device with less display unevenness than, for example, a light-emitting device using polysilicon for the semiconductor film 508 can be provided. Alternatively, for example, smart glasses or a head-mounted display can be provided.

[0419] Furthermore, metal oxide can be used for the semiconductor film 508. This allows the pixel circuit to retain an image signal for a longer period of time compared to a pixel circuit that uses a transistor with amorphous silicon as the semiconductor film. Specifically, the selection signal can be supplied at a frequency of less than 30 Hz, preferably less than 1 Hz, and more preferably less than once per minute while suppressing the occurrence of flicker. As a result, fatigue accumulated in the user of the electronic device can be reduced. Furthermore, power consumption associated with driving can be reduced.

[0420] An oxide semiconductor can be used for the semiconductor film 508. Specifically, an oxide semiconductor containing indium, an oxide semiconductor containing indium, gallium, and zinc, or an oxide semiconductor containing indium, gallium, zinc, and tin can be used for the semiconductor film 508.

[0421] Note that by using an oxide semiconductor for the semiconductor film, a transistor having a smaller leakage current in an off state than a transistor using amorphous silicon for the semiconductor film can be obtained. Therefore, it is preferable to use a transistor using an oxide semiconductor for the semiconductor film as a switch or the like. Note that a circuit using a transistor using an oxide semiconductor for the semiconductor film as a switch can hold the potential of a floating node for a longer time than a circuit using a transistor using amorphous silicon for the semiconductor film as a switch.

[0422] When an oxide semiconductor is used for the semiconductor film, the light-emitting and receiving device 720 has a structure in which the oxide semiconductor is used for the semiconductor film and a light-emitting device with an MML (metal maskless) structure. This structure can significantly reduce leakage current that can flow through a transistor and leakage current that can flow between adjacent light-emitting devices (also referred to as lateral leakage current or side leakage current). Furthermore, with this structure, when an image is displayed on a display device, a viewer can observe one or more of image clarity, image sharpness, high saturation, and a high contrast ratio. Note that a structure in which leakage current that can flow through a transistor and lateral leakage current between light-emitting devices are extremely low can provide a display (also referred to as true black display) with extremely low light leakage (so-called white floating) that can occur during black display.

[0423] In particular, among light-emitting devices with an MML structure, by applying the SBS structure described above, the layers provided between the light-emitting devices (for example, organic layers used in common between the light-emitting devices, also called common layers) are configured to be separated, thereby making it possible to achieve a display with no side leakage or extremely little side leakage.

[0424] Next, a cross-sectional view of the light emitting and receiving device will be shown in Fig. 14. Fig. 14 shows a cross-sectional view of the light emitting and receiving device shown in Fig. 12A.

[0425] The cross-sectional view of FIG. 14 shows a cross-sectional view of a part of the region including the FPC 713 and the wiring 706, and a part of the display region 701 including the pixel 703(i, j).

[0426] 14 , the light emitting and receiving device 700 has a functional layer 520 between a first substrate 510 and a second substrate 770. The functional layer 520 includes the transistors (M11, M12, M13, M14, M15, M16, M17) and capacitance elements (C2, C3) described in FIG. 13 , as well as wiring (VS, VG, V1, V2, V3, V4, V5) that electrically connect these elements. Note that in FIG. 14 , the functional layer 520 includes a pixel circuit 530X(i, j), a pixel circuit 530S(i, j), and a drive circuit GD, but is not limited to this.

[0427] Furthermore, the pixel circuits formed in the functional layer 520 (for example, the pixel circuits 530X(i,j) and 530S(i,j) shown in FIG. 14 ) are electrically connected to the light-emitting devices and light-receiving devices formed on the functional layer 520 (for example, the light-emitting devices 550X(i,j) and 550S(i,j) shown in FIG. 14 ). Specifically, the light-emitting devices 550X(i,j) are electrically connected to the pixel circuits 530X(i,j) via wiring 591X, and the light-receiving devices 550S(i,j) are electrically connected to the pixel circuits 530S(i,j) via wiring 591S. Furthermore, an insulating layer 705 is provided on the functional layer 520, the light-emitting devices, and the light-receiving devices, and the insulating layer 705 functions to bond the second substrate 770 and the functional layer 520 together.

[0428] Note that a substrate provided with touch sensors arranged in a matrix can be used as the second substrate 770. For example, a substrate provided with a capacitive touch sensor or an optical touch sensor can be used as the second substrate 770. In this way, the light-emitting and receiving device of one embodiment of the present invention can be used as a touch panel.

[0429] Note that the structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0430] 15A to 17B , the electronic devices according to one embodiment of the present invention can be partially equipped with a light-emitting and receiving device according to one embodiment of the present invention.

[0431] 15A to 17B are diagrams illustrating the structure of an electronic device of one embodiment of the present invention. FIG. 15A is a block diagram of the electronic device, and FIGS. 15B to 15E are perspective views illustrating the structure of the electronic device. FIGS. 16A to 16E are perspective views illustrating the structure of the electronic device. FIGS. 17A and 17B are perspective views illustrating the structure of the electronic device.

[0432] An electronic device 5200B described in this embodiment includes an arithmetic device 5210 and an input / output device 5220 (see FIG. 15A).

[0433] The arithmetic unit 5210 has a function of receiving operation information and a function of supplying image information based on the operation information.

[0434] The input / output device 5220 has a display unit 5230, an input unit 5240, a detection unit 5250, a communication unit 5290, a function to supply operation information, and a function to be supplied with image information. The input / output device 5220 also has a function to supply detection information, a function to supply communication information, and a function to be supplied with communication information.

[0435] The input unit 5240 has a function of supplying operation information. For example, the input unit 5240 supplies operation information based on an operation by the user of the electronic device 5200B.

[0436] Specifically, the input unit 5240 can use a keyboard, hardware buttons, a pointing device, a touch sensor, an illuminance sensor, an imaging device, a voice input device, an eye-gaze input device, an attitude detection device, or the like.

[0437] The display portion 5230 has a function of displaying a display panel and displaying image information. For example, the display panel described in Embodiment 3 can be used as the display portion 5230.

[0438] The detection unit 5250 has a function of supplying detection information, for example, a function of detecting the surrounding environment in which the electronic device is used and supplying the detected information.

[0439] Specifically, an illuminance sensor, an imaging device, a posture detection device, a pressure sensor, a human sensor, or the like can be used for the detection unit 5250 .

[0440] The communication unit 5290 has a function of receiving and supplying communication information. For example, it has a function of connecting to other electronic devices or communication networks by wireless communication or wired communication. Specifically, it has functions such as wireless local area communication, telephone communication, and short-range wireless communication.

[0441] FIG. 15B shows an electronic device having an outer shape that conforms to a cylindrical pillar or the like. An example of such an electronic device is a digital signage device. The display panel of one embodiment of the present invention can be applied to the display portion 5230. Note that the display panel may have a function of changing the display method depending on the illuminance of the usage environment. Furthermore, the display panel has a function of detecting the presence of a person and changing the display content. This allows the display panel to be installed on a pillar of a building, for example. Alternatively, advertisements or notices can be displayed. Alternatively, the display panel can be used for digital signage or the like.

[0442] 15C shows an electronic device having a function of generating image information based on the trajectory of a pointer used by a user. Examples include an electronic whiteboard, an electronic bulletin board, and an electronic signboard. Specifically, a display panel with a diagonal length of 20 inches or more, preferably 40 inches or more, and more preferably 55 inches or more can be used. Alternatively, multiple display panels can be arranged to form a single display area. Alternatively, multiple display panels can be arranged to form a multi-screen.

[0443] FIG. 15D shows an electronic device that can receive information from another device and display it on the display unit 5230. An example of such an electronic device is a wearable electronic device. Specifically, it can display several options, or the user can select several options and send a reply to the sender of the information. Alternatively, it can have a function to change the display method depending on the illuminance of the usage environment. This can reduce the power consumption of the wearable electronic device, for example. Alternatively, it can display an image on the wearable electronic device so that it can be used effectively even in environments with strong external light, such as outdoors on a sunny day.

[0444] <<Configuration Example 4 of Electronic Device>> Fig. 15E shows an electronic device having a display unit 5230 with a curved surface that gently curves along the side of the housing. An example is a mobile phone. The display unit 5230 includes a display panel, which has a function of displaying information on, for example, the front, side, top, and back of the mobile phone. This allows information to be displayed not only on the front, but also on the side, top, and back of the mobile phone.

[0445] <<Configuration Example 5 of Electronic Device>> Fig. 16A shows an electronic device that can receive information from the Internet and display it on the display unit 5230. An example of such an electronic device is a smartphone. For example, a created message can be checked on the display unit 5230. Alternatively, the created message can be transmitted to another device. Alternatively, the smartphone may have a function to change the display method depending on the illuminance of the usage environment. This can reduce the power consumption of the smartphone. Alternatively, for example, an image can be displayed on the smartphone so that the smartphone can be used suitably even in an environment with strong external light, such as outdoors on a sunny day.

[0446] FIG. 16B shows an electronic device that can use a remote controller as the input unit 5240. An example is a television system. Alternatively, for example, information can be received from a broadcasting station or the Internet and displayed on the display unit 5230. Alternatively, a user can be photographed using the detection unit 5250. An image of the user can be transmitted. Alternatively, the user's viewing history can be acquired and provided to a cloud service. Alternatively, recommendation information can be acquired from a cloud service and displayed on the display unit 5230. Alternatively, a program or video can be displayed based on the recommendation information. Alternatively, for example, the device has a function to change the display method depending on the illuminance of the usage environment. This allows images to be displayed on the television system so that it can be used appropriately even when strong external light shines indoors on a sunny day.

[0447] 16C shows an electronic device that can receive learning materials from the Internet and display them on the display unit 5230. An example is a tablet computer. Alternatively, a report can be input using the input unit 5240 and sent to the Internet. Alternatively, the results of corrections or evaluations of the report can be obtained from a cloud service and displayed on the display unit 5230. Alternatively, suitable learning materials can be selected and displayed based on the evaluations.

[0448] For example, an image signal can be received from another electronic device and displayed on the display unit 5230. Alternatively, the display unit 5230 can be used as a sub-display by being placed on a stand or the like. This allows images to be displayed on the tablet computer so that the tablet computer can be used suitably even in an environment with strong external light, such as outdoors on a sunny day.

[0449] FIG. 16D shows an electronic device having multiple display units 5230. An example is a digital camera. For example, an image can be captured by the detection unit 5250 and displayed on the display unit 5230. Alternatively, the captured image can be displayed on the detection unit. Alternatively, the captured image can be decorated using the input unit 5240. Alternatively, a message can be attached to the captured image. Alternatively, the captured image can be sent to the Internet. Alternatively, the electronic device has a function to change the capture conditions depending on the illuminance of the usage environment. This allows the subject to be displayed on the digital camera so that it can be viewed appropriately even in an environment with strong external light, such as outdoors on a sunny day.

[0450] 16E shows an electronic device that can control another electronic device using the electronic device of this embodiment as a master, with the other electronic device used as a slave. One example is a portable personal computer. For example, part of the image information can be displayed on the display unit 5230, and another part of the image information can be displayed on the display unit of the other electronic device. Alternatively, an image signal can be supplied. Alternatively, information to be written can be obtained from the input unit of the other electronic device using the communication unit 5290. This allows, for example, a portable personal computer to utilize a large display area.

[0451] FIG. 17A shows an electronic device having a detection unit 5250 that detects acceleration or orientation. An example is a goggle-type electronic device. Alternatively, the detection unit 5250 can provide information related to the user's position or the direction the user is facing. Alternatively, the electronic device can generate image information for the right eye and image information for the left eye based on the user's position or the direction the user is facing. Alternatively, the display unit 5230 has a display area for the right eye and a display area for the left eye. This allows, for example, an immersive virtual reality space image to be displayed on the goggle-type electronic device.

[0452] 17B shows an electronic device having a detection unit 5250 that detects an imaging device, acceleration, or orientation. An example is a glasses-type electronic device. Alternatively, the detection unit 5250 can provide information related to the user's position or the direction the user is facing. Alternatively, the electronic device can generate image information based on the user's position or the direction the user is facing. This allows, for example, information to be attached to a real landscape and displayed. Alternatively, an image of an augmented reality space can be displayed on the glasses-type electronic device.

[0453] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0454] In this example, light-receiving devices according to one embodiment of the present invention (Device 1 and Device 2) described in the embodiment and comparative devices (Comparative Device 3 and Comparative Device 4) were fabricated, and the characteristics thereof were evaluated. The results are described.

[0455] The structural formulae of the organic compounds used in Device 1, Device 2, Comparative Device 3, and Comparative Device 4 are shown below.

[0456]

[0457] (Method for manufacturing light-receiving device 1) As shown in FIG. 18 , the light-receiving device 1 has a structure in which a hole injection layer 911, a hole transport layer 912, an active 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 903 is stacked on the electron injection layer 915.

[0458] First, a reflective film was formed on a glass substrate 900. Specifically, a reflective film was formed to a thickness of 100 nm by sputtering using an alloy (abbreviated as APC) containing silver (Ag), palladium (Pd), and copper (Cu) as a target. After that, indium oxide-tin oxide (abbreviated as ITSO) containing silicon or silicon oxide was formed by sputtering to form a first electrode 901. The film thickness was 100 nm, and the electrode area was 4 mm. ２ (2 mm x 2 mm).

[0459] Next, as a pretreatment for forming a light-emitting device on the substrate, the surface of the substrate was washed with water and baked at 200° C. for 1 hour. −４ The substrate was introduced into a vacuum deposition apparatus whose internal pressure had been reduced to about Pa, and vacuum baking was performed at 180°C for 60 minutes in a heating chamber of the vacuum deposition apparatus. Thereafter, the substrate was allowed to cool naturally to 30°C or below.

[0460] 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,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf) and an electron acceptor material (OCHD-003) having a molecular weight of 672 and containing fluorine were co-deposited to a thickness of 10 nm on the first electrode 901 by an evaporation method using resistance heating so that the weight ratio of BBABnf:OCHD-003 was 1:0.1, thereby forming a hole-injection layer 911.

[0461] Next, BBABnf was evaporated on the hole injection layer 911 to a thickness of 40 nm to form a hole transport layer 912 .

[0462] Next, on the hole-transporting layer 912, Rubrene (5,6,11,12-tetraphenyltetracene) and 4,4′,4″-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: m-MTDATA) were co-evaporated to a thickness of 60 nm so that the weight ratio of Rubrene:m-MTDATA was 0.9:0.1, thereby forming an active layer 913.

[0463] Next, 2-[3′-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II) was evaporated onto the active layer 913 to a thickness of 10 nm, and then 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen) was evaporated onto the active layer 913 to a thickness of 10 nm, thereby forming an electron transport layer 914.

[0464] 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 .

[0465] Next, Ag and Mg were co-deposited on the electron injection layer 915 to a thickness of 10 nm so that the volume ratio of Ag:Mg was 1:0.1, and then ITSO was deposited by sputtering to a thickness of 40 nm to form a second electrode 903, thereby producing the light-receiving device 1. The second electrode 903 is a semi-transmissive / semi-reflective electrode that has the function of reflecting light and the function of transmitting light.

[0466] Next, the methods for fabricating Device 2, Comparative Device 3, and Comparative Device 4 will be described.

[0467] (Method of Fabricating Device 2) Device 2 differs from Device 1 in that 4,4′-bis(N-{4-[N′-(3-methylphenyl)-N′-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD) was used in place of m-MTDATA used in the active layer 913 of Device 1. That is, Device 2 was fabricated in the same manner as Device 1, except that the active layer 913 was formed on the hole transport layer 912 by co-depositing Rubrene and DNTPD to a thickness of 60 nm in a weight ratio of Rubrene:DNTPD = 0.9:0.1.

[0468] (Method of Fabricating Comparative Device 3) Comparative Device 3 differs from Device 1 in that N-(1,1′-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF) was used instead of m-MTDATA used in Device 1 for the active layer 913. That is, Comparative Device 3 was fabricated in the same manner as Device 1, except that the active layer 913 was formed on the hole transport layer 912 by co-depositing Rubrene and PCBBiF to a thickness of 60 nm in a weight ratio of Rubrene:PCBBiF = 0.9:0.1.

[0469] (Method of Fabricating Comparative Device 4) Comparative Device 4 differs from Device 1 in that BBABnf was used instead of m-MTDATA used in Device 1 for the active layer 913. That is, Comparative Device 4 was fabricated in the same manner as Device 1, except that the active layer 913 was formed on the hole transport layer 912 by co-depositing Rubrene and BBABnf to a thickness of 60 nm in a weight ratio of Rubrene:BBABnf = 0.9:0.1.

[0470] The device structures of Device 1, Device 2, Comparative Device 3, and Comparative Device 4 are summarized in the table below.

[0471]

[0472] 19 shows the absorption spectra of Rubrene, m-MTDATA, and DNTPD, which are materials used in the active layer 913 of Device 1 and Device 2. FIG. 20 shows the absorption spectra of PCBBiF and BBABnf, which are materials used in the active layer 913 of Comparative Device 3 and Comparative Device 4.

[0473] 19 and 20, Rubrene had an absorption peak at 530 nm. That is, it was found that at least one of the multiple peaks in the absorption spectrum of Rubrene had a wavelength of 400 nm or more and 700 nm or less. Furthermore, m-MTDATA, DNTPD, PCBBiF, and BBABnf had maximum absorption peaks at 351 nm, 334 nm, 354 nm, and 342 nm, respectively. That is, it was found that the maximum peak wavelengths in the absorption spectra of m-MTDATA, DNTPD, PCBBiF, and BBABnf were 400 nm or less.

[0474] The HOMO and LUMO levels of Rubrene, m-MTDATA, DNTPD, PCBBiF, and BBABnf are shown in the table below and in FIG. 21 . The HOMO and LUMO levels were measured by cyclic voltammetry (CV) measurements. An electrochemical analyzer (manufactured by BAS Inc., model number: ALS Model 600A or 600C) was used for the measurements. In FIG. 21 , the bottom side of the rectangle listing the substance name represents the HOMO level of the substance, and the top side represents the LUMO level of the substance.

[0475]

[0476] From the above table and Figure 21, it was found that the absorption spectra and HOMO levels of m-MTDATA, DNTPD, and PCBBiF are higher than the HOMO level of rubrene, and the HOMO level of BBABnf is lower than the HOMO level of rubrene. It was also found that the difference between the HOMO level of rubrene and the HOMO level of m-MTDATA was 0.47 eV, the difference between the HOMO level of rubrene and the HOMO level of DNTPD was 0.29 eV, and the difference between the HOMO level of rubrene and the HOMO level of PCBBiF was 0.09 eV. It was also found that the LUMO level of rubrene was -3.5 eV or more and -2.5 eV or less.

[0477] The absorption spectra, HOMO levels, and LUMO levels of Rubrene, m-MTDATA, DNTPD, PCBBiF, and BBABnf described above indicate that Rubrene has the potential to function as the first organic compound described in embodiment 1, and m-MTDATA, DNTPD, PCBBiF, and BBABnf have the potential to function as the second organic compound described in embodiment 1.

[0478] Subsequently, various measurements were carried out on Device 1, Device 2, Comparative Device 3, and Comparative Device 4.

[0479] 22 and 23 show the current-voltage characteristics of Device 1, Device 2, Comparative Device 3, and Comparative Device 4. The measurements were performed using monochromatic light with a wavelength λ of 500 nm at an irradiance of 12.5 μW / cm ２ 22 and 23, the horizontal axis represents voltage and the vertical axis represents current I.

[0480] 22, it was confirmed that the current of Device 1 and Device 2 was amplified by light irradiation. Furthermore, when Device 1 and Device 2 were compared, it was found that Device 1 had higher light sensitivity. It was also confirmed that Device 1 and Device 2 had low dark current.

[0481] <Spectral Sensitivity> Fig. 24 shows the wavelength dependence of the external quantum efficiency (EQE) of Device 1, Device 2, Comparative Device 3, and Comparative Device 4. The EQE was measured at an irradiance of 12.5 µW / cm ２ 24, the horizontal axis represents wavelength λ and the vertical axis represents EQE.

[0482] 24, it was confirmed that the light receiving sensitivity to visible light of Device 1 and Device 2 was higher than that of Comparative Device 3 and Comparative Device 4. Furthermore, when Device 1 and Device 2 were compared, it was found that Device 1 had higher light receiving sensitivity.

[0483] As described above, Device 1 and Device 2 had higher light-receiving sensitivity than Comparative Device 1 and Comparative Device 2. This suggests that the light-receiving sensitivity of Device 1 and Device 2 was enhanced by Rubrene functioning as the first organic compound described in Embodiment 1 and m-MTDATA and DNTPD functioning as the second organic compound described in Embodiment 1. It was also confirmed that, in order to operate the light-receiving device of one embodiment of the present invention, the difference between the HOMO level of the first organic compound and the HOMO level of the second organic compound is preferably 0.2 eV or more.

[0484] Furthermore, as described above, when Device 1 using m-MTDATA is compared with Device 2 using DNTPD, it is found that Device 1 has higher light-receiving sensitivity. This indicates that, in order to operate the light-receiving device of one embodiment of the present invention, it is more preferable that the difference between the HOMO level of the first organic compound and the HOMO level of the second organic compound be 0.4 eV or more.

[0485] 100: light-emitting device, 101: first electrode, 102: second electrode, 103: EL layer, 103a: EL layer, 103b: EL layer, 103c: EL layer, 103B: EL layer, 103G: EL layer, 103R: EL layer, 103PS: light-receiving layer, 104B: hole injection / transport layer, 104G: hole injection / transport layer, 104R: hole injection / transport layer, 104PS: first transport layer, 105B: light-emitting layer, 105G: light-emitting layer, 105R: light-emitting layer, 105PS: active layer, 106: charge generation layer, 106a: charge generation layer, 106b: charge generation layer, 107: insulating layer, 108B: electron transport layer, 108G: electron transport layer, 108R: electron transport layer, 108PS: second transport layer, 109: electron injection layer, 110B: sacrificial layer, 110G: sacrificial layer, 110R: sacrificial layer, 110PS: sacrificial layer, 111: hole injection layer, 111a: hole injection layer, 111b: hole injection layer, 112: hole transport layer, 112a: hole transport layer, 112b: hole transport layer, 113: light emitting layer, 113a: light emitting layer, 113b: light emitting layer, 113c: light emitting layer, 114: electron transport layer, 114a: electron transport layer, 114b: electron transport layer, 115: electron injection layer, 115a: electron injection layer, 115b: electron injection layer, 130: contact connection portion, 131: connection portion, 200: light-receiving device, 201: first electrode, 202: second electrode, 203: light-receiving layer, 211: first carrier injection layer, 212: first carrier transport layer, 212_1: hole transport material, 213: active layer, 213_1: first organic compound, 213_2: second organic compound, 214: second carrier transport layer, 214_1: electron transport material, 215: second carrier injection layer, 501C: insulating film, 501D: insulating film, 504: conductive film, 506: insulating film, 508: semiconductor film, 508A: region, 508B: region, 508C: region, 510: first Substrate, 512A: conductive film, 512B: conductive film, 516: insulating film, 516A: insulating film, 516B: insulating film, 518: insulating film, 520: functional layer, 524: conductive film, 528: partition wall, 530: pixel circuit, 530S: pixel circuit, 530X: pixel circuit, 531: pixel circuit, 550: light-emitting device, 550B: light-emitting device, 550G: light-emitting device, 550R: light-emitting device, 550X: light-emitting device, 550S: light-receiving device, 550PS: light-receiving device, 551B: electrode, 551C: connection electrode, 551G: electrode, 551R: electrode, 551PS: electrode, 552: electrode,580: gap, 591S: wiring, 591X: wiring, 700: light emitting / receiving device, 701: display area, 702B: subpixel, 702G: subpixel, 702R: subpixel, 702PS: subpixel, 703: pixel, 704: circuit, 705: insulating layer, 706: wiring, 710: substrate, 711: substrate, 712: IC, 713: FPC, 720: light emitting / receiving device, 800: substrate, 801a: electrode, 801b: electrode, 802: electrode, 803a: EL layer, 803b: light receiving layer, 805 a: light-emitting device, 805b: light-receiving device, 810: light-emitting and receiving device, 810A: light-emitting and receiving device, 810B: light-emitting and receiving device, 900: glass substrate, 901: first electrode, 903: second electrode, 911: hole injection layer, 912: hole transport layer, 913: active layer, 914: electron transport layer, 915: electron injection layer, 5200B: electronic device, 5210: arithmetic unit, 5220: input / output device, 5230: display unit, 5240: input unit, 5250: detection unit, 5290: communication unit,

Claims

1. A light-receiving device having a light-receiving layer between a pair of electrodes, wherein the light-receiving layer has an active layer, the active layer has a first organic compound and a second organic compound, in the active layer, the first organic compound and the second organic compound are mixed, the absorption spectrum of the first organic compound has one or more peaks, at least one peak wavelength of the peaks is 400 nm or more and 700 nm or less, and the HOMO level of the second organic compound is higher than the HOMO level of the first organic compound.

2. The light-receiving device according to claim 1, wherein the difference between the HOMO level of the first organic compound and the HOMO level of the second organic compound is 0.2 eV or more and 1.5 eV or less.

3. The light-receiving device according to claim 1, wherein the difference between the HOMO level of the first organic compound and the HOMO level of the second organic compound is 0.4 eV or more and 1.5 eV or less.

4. The light-receiving device according to any one of claims 1 to 3, wherein the LUMO level of the first organic compound is -3.5 eV or more and -2.5 eV or less.

5. The light-receiving device according to any one of claims 1 to 4, wherein the maximum peak wavelength of the absorption spectrum of the second organic compound is 400 nm or less.

6. The light-receiving device according to any one of claims 1 to 5, wherein the first organic compound is a polyacene derivative.

7. The light-receiving device according to any one of claims 1 to 6, The second organic compound has a hole mobility of 10 －６ cm ２ / Vs or more, and is a light-receiving device.

8. The light-receiving device according to any one of claims 1 to 7, wherein the second organic compound is a compound having a π-electron-excessive heteroaromatic ring or an aromatic amine.

9. A light-emitting and receiving device having the light-receiving device according to any one of claims 1 to 8 and a light-emitting device.

10. An electronic device having the light-emitting and receiving device according to claim 9 and a detection unit, an input unit, or a communication unit.