Light-receiving device and light-emitting and light-receiving apparatus

Abstract

A light-receiving device is provided that suppresses the rise in driving voltage. The light-receiving device is provided as follows: a light-emitting device comprising a light-receiving layer between a pair of electrodes, wherein the light-receiving layer includes an active layer, a buffer layer, and an electron transport layer, the buffer layer being located between the active layer and the electron transport layer and in contact with the active layer, the buffer layer comprising an organic compound having electron-withdrawing groups; or a light-emitting device comprising a light-receiving layer between a pair of electrodes, wherein the light-receiving layer includes an active layer, a buffer layer, and an electron transport layer, the buffer layer being located between the active layer and the electron transport layer and in contact with the active layer, the buffer layer comprising a heteroaromatic compound having electron-withdrawing groups.

Description

[Technical Field]

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

[0002] Note that one embodiment of the present invention is not limited to the above-described technical field. The technical field of one embodiment of the invention disclosed in this specification relates to an object, method, or manufacturing method. Furthermore, one embodiment of the present invention relates to a process, machine, manufacture, or composition of matter. Thus, more specifically, examples of the technical field of one embodiment of the present invention disclosed in this specification include semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, methods for driving these devices, or methods for manufacturing these devices. [Previous Technology]

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

[0004] [Patent Document 1] No. WO2020 / 152556 [Summary of the Invention]

[0005] One objective of one embodiment of the present invention is to provide a light-receiving device that suppresses the increase in driving voltage. Another objective of one embodiment of the present invention is to provide a light-emitting device that suppresses the increase in power consumption. Another objective of one embodiment of the present invention is to provide an electronic device that suppresses the increase in power consumption. Furthermore, another objective of one embodiment of the present invention is to provide a novel light-receiving device, a novel light-emitting device, or a novel electronic device.

[0006] Note that the description of these objectives does not preclude the existence of other objectives. One embodiment of the present invention does not need to achieve all of the above objectives. Objectives other than those described above are obvious from the description in the specification, drawings, claims, etc., and objectives other than those described above can be extracted from the description in the specification, drawings, claims, etc.

[0007] One embodiment of the present invention is a light-receiving device, which includes a light-receiving layer between a pair of electrodes. The light-receiving layer includes an active layer, a buffer layer and an electron transport layer. The buffer layer is located between the active layer and the electron transport layer and is in contact with the active layer. The buffer layer contains an organic compound having electron-withdrawing groups.

[0008] In addition, one embodiment of the present invention is a light-receiving device, which includes a light-receiving layer between a pair of electrodes. The light-receiving layer includes an active layer, a buffer layer and an electron transport layer. The buffer layer is located between the active layer and the electron transport layer and is in contact with the active layer. The buffer layer contains a heteroaromatic compound having electron-withdrawing groups.

[0009] In addition, one embodiment of the present invention is a light-receiving device, which includes a light-receiving layer between a pair of electrodes. The light-receiving layer includes an active layer, a buffer layer and an electron transport layer. The buffer layer is located between the active layer and the electron transport layer and is in contact with the active layer. The buffer layer contains a heteroaromatic compound having multiple cyano groups.

[0010] In addition, in the above structures, one embodiment of the present invention is a light-receiving device, wherein the heteroaromatic compound has a fused heteroaromatic ring.

[0011] In the above structures, preferably, the electron transport layer contains a first organic compound, which is a π-electron-deficient heteroaromatic compound.

[0012] Furthermore, in the above structures, preferably, the electron transport layer comprises a first organic compound, which is any one of the following: a metal complex comprising a quinoline skeleton, a metal complex comprising a benzoquinoline skeleton, a metal complex comprising a acetazole skeleton, a metal complex comprising a thiazole skeleton, an acediazole derivative, a triazole derivative, an imidazole derivative, an acetazole derivative, a thiazole derivative, a phenoline derivative, a quinoline derivative comprising a quinoline ligand, a benzoquinoline derivative, a quinoline derivative, a dibenzoquinoline derivative, a pyridine derivative, a bipyridine derivative, and a pyrimidine derivative.

[0013] In the above structures, preferably, the electron transport layer contains a first organic compound, which is a compound having a triazine ring.

[0014] In the above structures, preferably, the electron transport layer contains a first organic compound, which is an organic compound represented by the general formula (Ge-1).

[0015] [Chemical Formula 1]

[0016] In the above formula (Ge-1), Ar1 to Ar3 independently represent hydrogen, an aryl group with 6 or more but less than 30 substituted or unsubstituted carbon atoms, or a heteroaryl group with 2 to 30 substituted or unsubstituted carbon atoms, respectively. X1 and X2 independently represent carbon or nitrogen. When one or both of X1 and X2 are carbon, carbon is bonded to hydrogen, an aryl group with 6 or more but less than 30 substituted or unsubstituted carbon atoms, a heteroaryl group with 2 to 30 substituted or unsubstituted carbon atoms, an alkyl group with 1 to 20 substituted or unsubstituted carbon atoms, or a cycloalkyl group with 1 to 20 substituted or unsubstituted carbon atoms.

[0017] In the above structures, preferably, the electron transport layer contains a first organic compound, which is an organic compound represented by the general formula (Ge-2).

[0018] [Chemical Formula 2]

[0019] In the above formula (Ge-2), Ar1 to Ar3 independently represent aryl groups with 6 or more but less than 30 substituted or unsubstituted carbon atoms, or heteroaryl groups with 2 to 30 substituted or unsubstituted carbon atoms, and X2 represents carbon or nitrogen. When X2 is carbon, the carbon is bonded to hydrogen, aryl groups with 6 or more but less than 30 substituted or unsubstituted carbon atoms, heteroaryl groups with 2 to 30 substituted or unsubstituted carbon atoms, alkyl groups with 1 to 20 substituted or unsubstituted carbon atoms, or cycloalkyl groups with 1 to 20 substituted or unsubstituted carbon atoms.

[0020] In the above structures, preferably, the electron transport layer contains a first organic compound, which is an organic compound represented by the general formula (Ge-3).

[0021] [Chemical Formula 3]

[0022] In the above formula (Ge-3), Ar1 to Ar3 independently represent aryl groups with 6 or more but less than 30 substituted or unsubstituted carbon atoms, or heteroaryl groups with 2 to 30 substituted or unsubstituted carbon atoms.

[0023] Furthermore, in the above structures, one embodiment of the present invention is a light-receiving device, wherein preferably, the electron transport layer comprises a first organic compound, and the first organic compound is an organic compound represented by the general formula (Ge-4).

[0024] [Chemical Formula 4]

[0025] In the above formula (Ge-4), Ar3 represents an aryl group with 6 or more but less than 30 substituted or unsubstituted carbon atoms, or a heteroaryl group with 2 to 30 substituted or unsubstituted carbon atoms, and R1 to R10 represent hydrogen, an alkyl group with 1 to 20 substituted or unsubstituted carbon atoms, a cycloalkyl group with 3 to 20 substituted or unsubstituted carbon atoms, an aryl group with 6 or more but less than 30 substituted or unsubstituted carbon atoms, or a heteroaryl group with 2 to 30 substituted or unsubstituted carbon atoms, respectively.

[0026] In addition, one embodiment of the present invention is a light-receiving device, which includes a light-receiving layer between a pair of electrodes. The light-receiving layer includes an active layer, a buffer layer and an electron transport layer. The buffer layer is located between the active layer and the electron transport layer and is in contact with the active layer. The active layer contains a first organic compound, the buffer layer contains a second organic compound, and the electron transport layer contains a third organic compound. The LUMO energy level of the second organic compound is higher than that of the first organic compound and lower than that of the third organic compound.

[0027] In addition, in the above structure, one embodiment of the present invention is a light-receiving device, wherein the difference between the LUMO energy level of the second organic compound and the LUMO energy level of the first organic compound is less than 0.5 eV.

[0028] In addition, in the above structure, one embodiment of the present invention is a light-receiving device, wherein the difference between the LUMO energy level of the second organic compound and the LUMO energy level of the third organic compound is less than 1.0 eV.

[0029] In addition, in the above structure, one embodiment of the present invention is a light-receiving device, wherein the LUMO energy level of the second organic compound is above -4.5 eV and below -3.0 eV.

[0030] Furthermore, one embodiment of the present invention is a light-receiving device including a light-receiving device and a light-emitting device having the above-described structures.

[0031] Furthermore, one embodiment of the present invention is an electronic device that includes a light-receiving device having the above-described structures, as well as a detection unit, an input unit, or a communication unit.

[0032] In the diagrams of this specification, the components are shown as independent blocks according to their functions. However, in reality, it is difficult to completely divide the components according to their functions, and a component may involve multiple functions.

[0033] According to one embodiment of the present invention, a light-receiving device that suppresses the increase in driving voltage can be provided. Furthermore, according to one embodiment of the present invention, a light-emitting device that suppresses the increase in power consumption can be provided. Furthermore, according to one embodiment of the present invention, an electronic device that suppresses the increase in power consumption can be provided. Additionally, according to one embodiment of the present invention, a novel light-receiving device, a novel light-emitting device, or a novel electronic device can be provided.

[0034] Note that the description of these effects does not preclude the existence of other effects. One embodiment of the present invention does not require all of the above-described effects. Effects other than those described above are obvious from the description in the specification, drawings, claims, etc., and effects other than those described above can be extracted from the description in the specification, drawings, claims, etc.

Implementation Method

[0037] The embodiments are described in detail using drawings. Note that the present invention is not limited to the following description, and those skilled in the art will readily understand that its methods and details can be varied in many ways without departing from the spirit and scope of the invention. Therefore, the present invention should not be construed as being limited only to the contents described in the embodiments shown below. In the structure of the invention described below, the same symbols are used across different drawings to represent the same parts or parts having the same function, and repeated descriptions are omitted.

[0038] Embodiment 1 In this embodiment, a light-receiving device according to one embodiment of the present invention will be described.

[0039] The light-receiving device of one embodiment of the present invention has the function of detecting light (hereinafter also referred to as light-receiving function).

[0040] Figures 1A to 1D are cross-sectional schematic diagrams of a light-receiving device 200 according to an embodiment of the present invention.

[0041] <<Basic Structure of the Light-Receiving Device>> The basic structure of the light-receiving device will be explained. Figure 1A shows a light-receiving device 200 including a light-receiving layer 203 between a pair of electrodes. Specifically, the light-receiving device 200 has a structure in which the light-receiving layer 203 is sandwiched between a first electrode 201 and a second electrode 202. The light-receiving layer 203 includes at least an active layer, a buffer layer, and a carrier transport layer. The buffer layer is located between the active layer and the carrier transport layer and is in contact with the active layer.

[0042] Furthermore, FIG. 1B shows an example of the stacked structure of the light-receiving layer 203 of the light-receiving device 200 as an embodiment of the present invention. The light-receiving layer 203 has a structure in which a first carrier transport layer 212, an active layer 213, a buffer layer 220, and a second carrier transport layer 214 are sequentially stacked on the first electrode 201. In other words, the buffer layer 220 is located between the active layer 213 and the second carrier transport layer 214, and is in contact with the active layer 213.

[0043] Furthermore, FIG1C shows another example of the stacked structure of the light-receiving layer 203 of the light-receiving device 200 as an embodiment of the present invention. The light-receiving layer 203 has a structure in which a first carrier injection layer 211, a first carrier transport layer 212, an active layer 213, a buffer layer 220, a second carrier transport layer 214, and a second carrier injection layer 215 are sequentially stacked on the first electrode 201. In other words, the buffer layer 220 is located between the active layer 213 and the second carrier transport layer 214, and is in contact with the active layer 213.

[0044] By providing a buffer layer 220 in the light-receiving device 200 of one embodiment of the present invention, the increase in the driving voltage of the light-receiving device 200 can be suppressed.

[0045] <<Specific Structure of the Light Receiving Device>> Next, the specific structure of the light receiving device 200, which is an embodiment of the present invention, will be described. Here, FIG1C will be used for description.

[0046] <First Electrode and Second Electrode> The first electrode 201 and the second electrode 202 can be formed using the materials that can be used for the first electrode 101 and the second electrode 102 of the light-emitting device as described in Embodiment 2.

[0047] For example, when the first electrode 201 is a reflective electrode and the second electrode 202 is a semi-transmissive-semi-reflective electrode, an optical microcavity resonator (microcavity) structure can be obtained. Thus, light of a specific wavelength to be detected is amplified, and a highly sensitive light-receiving device can be obtained.

[0048] <First Carrier Injection Layer> The first carrier injection layer 211 is a layer that injects holes from the light-receiving layer 203 into the first electrode 201, and contains a material with high hole injection capability. Examples of materials with high hole injection capability include aromatic amine compounds and composite materials containing hole transport materials and acceptor materials (electron acceptor materials). In this specification, the first carrier injection layer is sometimes referred to as a hole injection layer.

[0049] Furthermore, the first carrier injection layer 211 can be formed using the material of the hole injection layer 111 that can be used in a light-emitting device, as described in Embodiment 2.

[0050] <First Carrier Transport Layer> The first carrier transport layer 212 is a layer that transports holes generated by light incident on the active layer 213 to the first electrode 201, and includes a hole-transporting material. Preferably, the hole-transporting material is a material with a hole mobility of 10⁻⁶ cm² / Vs or higher. Furthermore, any material other than those described above can be used, as long as its hole transport capability is higher than its electron transport capability.

[0051] As a hole transport material, π-electron-rich heteroaromatic compounds or aromatic amines (compounds containing an aromatic amine skeleton) can be used.

[0052] In addition, carbazole derivatives, thiophene derivatives or furan derivatives can be used as hole transport materials.

[0053] In addition, the hole-transporting material is an aromatic monoamine compound or a heteroaromatic monoamine compound, and contains at least one skeleton selected from benzidine, carbazolylamine, dibenzofuranylamine, dibenzothiophenylamine, fumoniamine and spirofumoniamine.

[0054] In addition, the hole-transporting material is an aromatic amine compound or a heteroaromatic amine compound, and contains two or more skeletons selected from benzidine, carbazolylamine, dibenzofuranylamine, dibenzothiophenylamine, fumoniamine and spirofumoniamine.

[0055] Furthermore, when the hole-transporting material is an aromatic amine compound or a heteroaromatic amine compound and contains two or more skeletons selected from benzidine, carbazole amine, dibenzofuranylamine, dibenzothiophenylamine, geniylamine, and spirogeniylamine, a nitrogen atom is sometimes contained in two or more skeletons. For example, in an aromatic amine compound, when the geniyl group and the biphenyl group are bonded to a nitrogen atom, the compound can be considered an aromatic monoamine compound containing both a geniylamine skeleton and a benzidine skeleton.

[0056] Furthermore, the frameworks of benzidine, carbazolylamine, dibenzofuranylamine, dibenzothiophenylamine, spironylamine, and spironylamine mentioned above as hole transport materials may also have substituents. For example, aryl groups with 6 or more but less than 30 carbon atoms, alkyl groups with 1 to 20 carbon atoms (substituted or unsubstituted), cycloalkyl groups with 1 to 20 carbon atoms (substituted or unsubstituted), or heteroaryl groups with 4 or more but less than 30 carbon atoms (substituted or unsubstituted) can be mentioned as substituents.

[0057] Furthermore, the hole-transporting material is preferably a monoamine compound containing a triarylamine skeleton (the aryl group in the triarylamine compound includes heteroaryl groups). For example, the hole-transporting material is an organic compound represented by the following general formula (Gh-1).

[0058] [Chemical Formula 5]

[0059] In the above general formula (Gh-1), Ar11 to Ar13 independently represent hydrogen, aryl group with 6 or more but less than 30 substituted or unsubstituted carbon atoms, or heteroaryl group with 4 or more but less than 30 substituted or unsubstituted carbon atoms.

[0060] Alternatively, the hole-transporting material is an organic compound represented by the following general formula (Gh-2).

[0061] [Chemical Formula 6]

[0062] In the above general formula (Gh-2), Ar12 and Ar13 independently represent hydrogen, aryl group with 6 or more but less than 30 substituted or unsubstituted carbon atoms, or heteroaryl group with 4 or more but less than 30 substituted or unsubstituted carbon atoms, respectively. R511 to R520 independently represent hydrogen, aryl group with 6 or more but less than 30 substituted or unsubstituted carbon atoms, alkyl group with 1 to 20 substituted or unsubstituted carbon atoms, cycloalkyl group with 1 to 20 substituted or unsubstituted carbon atoms, or heteroaryl group with 4 or more but less than 30 substituted or unsubstituted carbon atoms, respectively. R519 and R520 may also be bonded to each other to form a ring.

[0063] Alternatively, the hole-transporting material is an organic compound represented by the following general formula (Gh-3).

[0064] [Chemical Formula 7]

[0065] In the above general formula (Gh-3), Ar12 and Ar13 independently represent aryl groups with 6 or more but less than 30 substituted or unsubstituted carbon atoms, or heteroaryl groups with 4 or more but less than 30 substituted or unsubstituted carbon atoms, respectively. R521 to R536 independently represent hydrogen, aryl groups with 6 or more but less than 30 substituted or unsubstituted carbon atoms, alkyl groups with 1 to 20 substituted or unsubstituted carbon atoms, cycloalkyl groups with 1 to 20 substituted or unsubstituted carbon atoms, or heteroaryl groups with 4 or more but less than 30 substituted or unsubstituted carbon atoms, respectively.

[0066] Alternatively, the hole-transporting material is an organic compound represented by the following general formula (Gh-4).

[0067] [Chemical Formula 8]

[0068] In the above general formula (Gh-4), Ar13 represents an aryl group with 6 or more but less than 30 substituted or unsubstituted carbon atoms, or a heteroaryl group with 4 or more but less than 30 substituted or unsubstituted carbon atoms. R511 to R520 and R540 to R549 independently represent hydrogen, an aryl group with 6 or more but less than 30 substituted or unsubstituted carbon atoms, an alkyl group with 1 to 20 substituted or unsubstituted carbon atoms, a cycloalkyl group with 1 to 20 substituted or unsubstituted carbon atoms, or a heteroaryl group with 4 or more but less than 30 substituted or unsubstituted carbon atoms. R519 and R520 may also be bonded to each other to form a ring, and R548 and R549 may also be bonded to each other to form a ring.

[0069] Furthermore, the hole-transporting material is an organic compound represented by the following general formula (Gh-5).

[0070] [Chemical Formula 9]

[0071] In the above general formula (Gh-5), Ar13 represents an aryl group with 6 or more but less than 30 substituted or unsubstituted carbon atoms, or a heteroaryl group with 4 or more but less than 30 substituted or unsubstituted carbon atoms. R511 to R520 and R550 to R559 independently represent hydrogen, an aryl group with 6 or more but less than 30 substituted or unsubstituted carbon atoms, an alkyl group with 1 to 20 substituted or unsubstituted carbon atoms, a cycloalkyl group with 1 to 20 substituted or unsubstituted carbon atoms, or a heteroaryl group with 4 or more but less than 30 substituted or unsubstituted carbon atoms. R519 and R520 may also be bonded to each other to form a ring.

[0072] Alternatively, the hole-transporting material is an organic compound represented by the following general formula (Gh-6).

[0073] [Chemical Formula 10]

[0074] In the above general formula (Gh-6), R560 to R574 independently represent hydrogen, aryl group with 6 or more but less than 30 substituted or unsubstituted carbon atoms, alkyl group with 1 to 20 substituted or unsubstituted carbon atoms, cycloalkyl group with 1 to 20 substituted or unsubstituted carbon atoms, or heteroaryl group with 4 or more but less than 30 substituted or unsubstituted carbon atoms.

[0075] R511 to R520 in the above general formula (Gh-2), R521 to R536 in the above general formula (Gh-3), R511 to R520 and R540 to R549 in the above general formula (Gh-4), R511 to R520 and R550 to R559 in the above general formula (Gh-5), and R560 to R574 in the above general formula (Gh-6) not only represent the above substituents, but also independently represent halogens, substituted or unsubstituted alkyl halides having 1 to 13 carbon atoms, cyano groups, or substituted or unsubstituted alkoxy groups having 1 to 13 carbon atoms.

[0076] Specifically, R511 to R520 in the above general formula (Gh-2), R521 to R536 in the above general formula (Gh-3), R511 to R520 and R540 to R549 in the above general formula (Gh-4), R511 to R520 and R550 to R559 in the above general formula (Gh-5), and R560 to R574 in the above general formula (Gh-6) are preferably substituents represented by the following formulas (R-1) to (R-38) and formulas (R-41) to (R-117). In the formulas, * represents a bond.

[0077] Furthermore, specifically, Ar11 to Ar13 in the above general formula (Gh-1), Ar12 and Ar13 in the above general formulas (Gh-2) and (Gh-3), and Ar13 in the above general formulas (Gh-4) and (Gh-5) are preferably substituents represented by the following formulas (R-41) to (R-117). In the formulas, * represents a bond.

[0078] [Chemical Formula 11]

[0079] [Chemical Formula 12]

[0080] [Chemical Formula 13]

[0081] [Chemical Formula 14]

[0082] [Chemical Formula 15]

[0083] Next, specific examples of organic compounds (hole-transporting materials) represented by the above general formulas (Gh-1) to (Gh-6) are shown below.

[0084] [Chemical Formula 16]

[0085] [Chemical Formula 17]

[0086] [Chemical Formula 18]

[0087] [Chemical Formula 19]

[0088] [Chemical Formula 20]

[0089] [Chemical Formula 21]

[0090] [Chemical Formula 22]

[0091] [Chemical Formula 23]

[0092] [Chemical Formula 24]

[0093] [Chemical Formula 25]

[0094] The organic compounds represented by the above structural formulas (201) to (302) are examples of organic compounds (hole transport materials) represented by the above general formulas (Gh-1) to (Gh-6), and specific examples are not limited thereto.

[0095] In addition, the first carrier transport layer 212 may also be formed using the material of the hole transport layer 112 that can be used in a light-emitting device, as described in Embodiment 2.

[0096] Furthermore, the first carrier transport layer 212 may have a single-layer structure or a stacked structure consisting of two or more layers made of the aforementioned materials.

[0097] In the light-receiving device shown in this embodiment, the first carrier transport layer 212 and the active layer 213 can use the same organic compound. By using the same organic compound for the first carrier transport layer 212 and the active layer 213, carriers can be efficiently transported from the first carrier transport layer 212 to the active layer 213, which is preferred.

[0098] <Active Layer> The active layer 213 is a layer that generates carriers based on incident light and contains a semiconductor. Examples of such semiconductors include inorganic semiconductors such as silicon and organic semiconductors containing organic compounds. In this embodiment, an example of using an organic semiconductor as the semiconductor contained in the active layer is shown. Because an organic semiconductor can be used, the light-emitting layer and the active layer can be formed using the same method (e.g., vacuum evaporation), and the manufacturing equipment can be shared, which is preferable.

[0099] In addition, the active layer 213 contains at least p-type semiconductor material and n-type semiconductor material.

[0100] As p-type semiconductor materials, examples of electronic donor organic semiconductor materials include Copper(II) phthalocyanine (CuPc), Tetraphenyldibenzoperiflanthene (DBP), Zinc phthalocyanine (ZnPc), Tin phthalocyanine (SnPc), and Quinacridone.

[0101] Furthermore, examples of p-type semiconductor materials include carbazole derivatives, thiophene derivatives, furan derivatives, and compounds containing an aromatic amine skeleton. Moreover, examples of p-type semiconductor materials include naphthalene derivatives, anthracene derivatives, pyrene derivatives, triphenylene derivatives, benzo[a]furan derivatives, benzo[a]thiophene derivatives, indole derivatives, dibenzo[a]furan derivatives, dibenzo[a]thiophene derivatives, indole-carbazole derivatives, violet derivatives, phthalocyanine derivatives, naphthylphthalocyanine derivatives, quinacridone derivatives, polyphenylene oxide derivatives, poly[a]benzylene derivatives, poly[a]benzylene derivatives, poly[a]benzylene derivatives, poly[a]benzylene derivatives, poly[a]benzylene derivatives, poly[a]benzylene derivatives, poly[a]benzylene derivatives, or poly[a]thiophene derivatives.

[0102] Furthermore, the p-type semiconductor material is preferably an organic compound represented by the following general formula (Ga-1).

[0103] [Chemical Formula 26]

[0104] In the above general formula (Ga-1), R21 to R30 independently represent hydrogen (including deuterium), substituted or unsubstituted alkyl groups having 1 to 13 carbon atoms, cycloalkyl groups having 3 to 13 carbon atoms, halogens, substituted or unsubstituted alkyl halides having 1 to 13 carbon atoms, cyano groups, substituted or unsubstituted alkoxy groups having 1 to 13 carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups having 2 to 30 carbon atoms, or substituted or unsubstituted vinyl groups, and m represents an integer from 1 to 5. When two of adjacent R21 to R24 or two of adjacent R25 to R28 are substituted or unsubstituted vinyl groups, they may also bond to each other to form a fused ring.

[0105] In the above general formula (Ga-1), R21 to R30 are preferably substituents represented by the following formulas (Ra-1) to (Ra-77). In the formula, * represents a bond.

[0106] [Chemical Formula 27]

[0107] [Chemical Formula 28]

[0108] [Chemical Formula 29]

[0109] Next, specific examples of p-type semiconductor materials represented by the above general formula (Ga-1) are shown below.

[0110] Chemical Formula 30]

[0111] [Chemical Formula 31]

[0112] The organic compounds represented by the above structural formulas (101) to (116) are examples of organic compounds represented by the above general formula (Ga-1), but specific examples of p-type semiconductor materials are not limited thereto. In the above general formula (Ga-1), as an example of a structure in which R27 and R28 are both vinyl groups and are bonded to each other to form a fused ring, the above structural formula (110) can be cited.

[0113] As n-type semiconductor materials, examples include fullerenes (e.g., C60, C70, etc.) and fullerene derivatives, which are electron-acceptor organic semiconductor materials. Fullerenes have a soccer ball shape, which is energy stable. Fullerenes have deep (low) HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital) energy levels. Because fullerenes have a deep LUMO energy level, their electron acceptor behavior is extremely high. Generally, when π-electron conjugation (resonance) expands in a plane, as in benzene, electron donor behavior becomes high. On the other hand, fullerenes have a spherical shape, and although π-electron conjugation expands, their electron acceptor behavior becomes high. With high electron acceptor behavior, charge separation is induced quickly and efficiently, which is beneficial for light-receiving devices. Both C60 and C70 have broad absorption bands in the visible light region. In particular, C70 has a larger π-electron conjugation system compared to C60, and also has a broader absorption band in the long wavelength region, so it is superior. In addition, fullerene derivatives include methyl [6,6]-phenyl-C71-butyrate (abbreviated as PC71BM), methyl [6,6]-phenyl-C61-butyrate (abbreviated as PC61BM), 1',1'',4',4''-tetrahydro-di[1,4]methanenaphthaleno[1,2:2',3',56,60:2'',3''][5,6]fullerene-C60 (abbreviated as ICBA), etc.

[0114] As n-type semiconductor materials, examples include metal complexes with a quinoline skeleton, metal complexes with a benzoquinoline skeleton, metal complexes with a benzoxazole skeleton, metal complexes with a thiazole skeleton, benzodiazepine derivatives, triazole derivatives, imidazole derivatives, benzoxazole derivatives, thiazole derivatives, phenoline derivatives, quinoline derivatives, benzoquinoline derivatives, quinoline derivatives, dibenzoquinoline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, naphthalene derivatives, anthracene derivatives, coumarin derivatives, rhodamine derivatives, triazine derivatives, quinone derivatives, etc.

[0115] Furthermore, the n-type semiconductor material is preferably an organic compound represented by any one of the following general formulas (Gb-1) to (Gb-3).

[0116] [Chemical Formula 32]

[0117] In the above general formulas (Gb-1) to (Gb-3), X30 to X45 independently represent oxygen or sulfur, n10 and n11 independently represent integers from 0 to 4, n20 to n26 independently represent integers from 0 to 3, at least one of n24 to n26 represents an integer from 1 to 3, and R100 to R117 independently represent hydrogen (including deuterium), cyano, substituted or unsubstituted alkyl groups having 1 to 13 carbon atoms, or alkyl groups having 3 to 13 carbon atoms. The terms R300 to R317 independently represent hydrogen (including deuterium), cyano, fluorine, chlorine, alkyl halide with 1 to 13 carbon atoms or halogen, substituted or unsubstituted alkyl halide with 1 to 13 carbon atoms or halogen.

[0118] In the above general formulas (Gb-1) to (Gb-3), R100 to R117 are preferably substituents represented by the following formulas (Rb-1) to (Rb-79) and (R-41) to (R-117). In the formulas, * represents a bond.

[0119] Furthermore, in the above general formulas (Gb-1) to (Gb-3), R300 to R317 are preferably substituents represented by the following formulas (Rb-1) to (Rb-4), (Rb-7) and (R-33) to (R-72). In the formulas, * represents a bond.

[0120] [Chemical Formula 33]

[0121] [Chemical Formula 34]

[0122] [Chemical Formula 35]

[0123] [Chemical Formula 36]

[0124] [Chemical Formula 37]

[0125] [Chemical Formula 38]

[0126] [Chemical Formula 39]

[0127] [Chemical Formula 40]

[0128] [Chemical Formula 41]

[0129] [Chemical Formula 42]

[0130] [Chemical Formula 43]

[0131] [Chemical Formula 44]

[0132] [Chemical Formula 45]

[0133] Next, specific examples of n-type semiconductor materials represented by the above general formula (Gb-1) are shown below.

[0134] [Chemical Formula 46]

[0135] The organic compounds represented by the above structural formulas (300) to (312) are an example of organic compounds (n-type semiconductor materials) represented by the above general formulas (Gb-1) to (Gb-3), but the specific examples are not limited thereto.

[0137] [Chemical Formula 47]

[0138] In the above general formula (Gc-1), R40 and R41 independently represent hydrogen, a chain alkyl group having 1 to 13 substituted or unsubstituted carbon atoms, a branched alkyl group having 3 to 13 carbon atoms, an aryl group having 6 to 13 substituted or unsubstituted carbon atoms, or an aromatic alkyl group having 6 to 13 substituted or unsubstituted carbon atoms, and R42 to R49 independently represent hydrogen, an alkyl group having 1 to 13 substituted or unsubstituted carbon atoms, a haloalkyl group having 1 to 13 substituted or unsubstituted carbon atoms, a cycloalkyl group having 3 to 13 substituted or unsubstituted carbon atoms, or a halogen.

[0139] In the above general formula (Gc-1), R40 and R41 preferably represent, independently, a chain alkyl group having 2 to 12 carbon atoms. Furthermore, they are more preferably branched alkyl groups. This improves solubility.

[0140] Next, specific examples of n-type semiconductor materials represented by the above general formula (Gc-1) are shown below.

[0141] [Chemical Formula 48]

[0142] The organic compound represented by the above structural formulas (400) to (403) is an example of an organic compound (n-type semiconductor material) represented by the above general formula (Gc-1), and the specific examples are not limited thereto.

[0143] In addition, the active layer 213 is preferably a laminated film containing a first layer of p-type semiconductor material and a second layer of n-type semiconductor material.

[0144] Furthermore, in the light-receiving devices of the above structures, the active layer 213 is preferably a mixed film containing p-type semiconductor material and n-type semiconductor material.

[0145] Furthermore, the HOMO energy level of the electron donor organic semiconductor material is preferably shallower (higher) than that of the electron acceptor organic semiconductor material. The LUMO energy level of the electron donor organic semiconductor material is preferably shallower (higher) than that of the electron acceptor organic semiconductor material.

[0146] In addition, spherical fullerenes can be used as electron acceptor organic semiconductor materials, and organic semiconductor materials with similar shapes to planar materials can be used as electron donor organic semiconductor materials. Molecules with similar shapes tend to aggregate easily. When the same type of molecule aggregates, the carrier transport can be improved because the energy levels of the molecular orbitals are similar.

[0147] <Buffer Layer> The buffer layer 220 is a layer that receives electrons from the active layer 213 and provides electrons to the second carrier transport layer 214. By providing the buffer layer 220 in the photodetector 200, the rise in the driving voltage of the photodetector 200 can be suppressed.

[0148] An organic compound having electron-withdrawing groups can be used in the buffer layer 220. The organic compound having electron-withdrawing groups has acceptor properties. Therefore, by using an organic compound having electron-withdrawing groups in the buffer layer 220, electrons can be readily accepted from the active layer 213 and readily provided to the second carrier transport layer 214, thereby suppressing the rise in the driving voltage of the photodetector 200.

[0149] Examples of electron-withdrawing groups include halogen groups (fluorine, chloro, iodo, etc.), cyano groups, isocyanate groups, nitro groups, halogenated alkyl groups, halogenated cycloalkyl groups, carbonyl groups, carboxyl groups, or acetyl groups. In particular, when an organic compound having a cyano group is used in the buffer layer 220, it is more effective in suppressing the rise in the driving voltage of the light-receiving device 200, and therefore is preferred.

[0150] As an organic compound having an electron-withdrawing group, a heteroaromatic compound having an electron-withdrawing group can be used. Specific examples of heteroaromatic compounds having electron-withdrawing groups include 2-cyanopyridine, 3-cyanopyridine, 4-cyanopyridine, pyrazino[2,3-f][1,10]phenoline-2,3-dicarboxynitrile (abbreviated as PPDN), 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabibenzene (abbreviated as HAT-CN), 2,3-bis(4-fluorophenyl)pyridino[2,3-b]pyrazine (abbreviated as F2PYPR), and 2,3,8,9,14,15-hexafluorodiquinoline[2,3-a:2',3'-c]phenazine (abbreviated as HATNA-F6), etc.

[0151] Note that among the above-mentioned heteroaromatic compounds with electron-withdrawing groups, heteroaromatic compounds with multiple cyano bonds, such as PPDN and HAT-CN, have higher acceptor properties and are therefore particularly preferred.

[0152] In addition, among the above-mentioned heteroaromatic compounds with electron-withdrawing groups, the film quality of heteroaromatic compounds with fused heteroaromatic rings such as PPDN, HAT-CN, F2PYPR, and HATNA-F6 is very stable to heat, so it is particularly good.

[0153] As other specific examples of organic compounds having electron-withdrawing groups, benzonitrile, 7,7,8,8-tetracyanoquinone dimethyl ether (TCNQ), 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinone dimethyl ether (F4-TCNQ), 3,6-difluoro-2,5,7,7,8,8-hexacyano-p-quinone dimethyl ether, chloroquinone, 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinone dimethyl ether (F6-TCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyrene-2-yl)malonitrile, perfluoropentabenzene, hexafluorophthaloyl bronze (F16CuPc), 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 diimidide (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 anhydride (abbreviation: NTCDA), etc. In addition, [3] axonylene derivatives with electron-withdrawing groups are preferred due to their high acceptor activity. Specifically, the following can be used: α,α',α''-1,2,3-cyclopropanetrimethylenetri[4-cyano-2,3,5,6-tetrafluorophenylacetonitrile], α,α',α''-1,2,3-cyclopropanetrimethylenetri[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)phenylacetonitrile], α,α',α''-1,2,3-cyclopropanetrimethylenetri[2,3,4,5,6-pentafluorophenylacetonitrile], etc.

[0154] In addition, an organic compound having a LUMO energy level that is higher than that of the n-type semiconductor material in the active layer 213 and lower than that of the electron transport material in the second carrier transport layer 214 can be used in the buffer layer 220. By using such an organic compound in the buffer layer 220, the carrier injection barrier from the active layer 213 to the second carrier transport layer 214 can be reduced, and the rise in the driving voltage of the photodetector 200 can be suppressed.

[0155] Figure 1D shows the relationship between the LUMO energy levels of the above-mentioned organic compounds. As shown in Figure 1D, the LUMO energy level of the organic compound 220_1 in the buffer layer 220 is higher than that of the n-type semiconductor material 213_n in the active layer 213 and lower than that of the electron transport material 214_1 in the second carrier transport layer 214. By using this organic compound 220_1 in the buffer layer 220, the carrier injection barrier from the active layer 213 to the second carrier transport layer 214 can be reduced, and the rise in the driving voltage of the photodetector 200 can be suppressed.

[0156] Furthermore, the difference between the LUMO energy level of the organic compound in the buffer layer 220 and the LUMO energy level of the n-type semiconductor material in the active layer 213 is preferably less than 0.5 eV. The buffer layer 220 can easily accept electrons from the active layer 213, thereby preventing the recombination of holes and electrons in the active layer 213.

[0157] Furthermore, the difference between the LUMO energy level of the organic compound in the buffer layer 220 and the LUMO energy level of the electron transport material in the second carrier transport layer 214 is preferably less than 1.0 eV. The buffer layer 220 can easily provide electrons to the second carrier transport layer 214.

[0158] Specifically, the LUMO energy level of the organic compound in the buffer layer 220 is preferably above -4.5 eV and below -3.0 eV.

[0159] Specific examples of organic compounds that can be used for buffer layer 220 with a LUMO energy level of -4.5 eV or higher and -3.0 eV or lower include PPDN, HAT-CN, diquinoline[2,3-a:2',3'-c]phenazine (abbreviated as HATNA), HATNA-F6, etc. Note that organic compounds that can be used for buffer layer 220 with a LUMO energy level of -4.5 eV or higher and -3.0 eV or lower are not limited to these.

[0160] Note that the organic compounds that can be used in the buffer layer 220 are not limited to organic compounds with a LUMO energy level of -4.5 eV or higher and -3.0 eV or lower. Preferably, an organic compound with an appropriate LUMO energy level is used in the buffer layer 220 according to the LUMO energy level of the n-type semiconductor material used in the active layer 213 and the LUMO energy level of the electron transport material used in the second carrier transport layer 214.

[0161] Furthermore, it is preferable to use an organic compound having electron-withdrawing groups and a LUMO energy level that is higher than that of the n-type semiconductor material in the active layer 213 and lower than that of the electron transport material in the second carrier transport layer 214 for the buffer layer 220. Furthermore, it is preferable to use an organic compound having electron-withdrawing groups and a LUMO energy level difference of 0.5 eV or less with the n-type semiconductor material in the active layer 213 for the buffer layer 220. Furthermore, it is preferable to use an organic compound having electron-withdrawing groups and a LUMO energy level difference of 1.0 eV or less with the electron transport material in the second carrier transport layer 214 for the buffer layer 220. Furthermore, it is preferable to use an organic compound having electron-withdrawing groups and a LUMO energy level of -4.5 eV or higher and -3.0 eV or lower for the buffer layer 220. By using such an organic compound in the buffer layer 220, the effect of suppressing the rise in the driving voltage of the photodetector 200 can be further improved.

[0162] Specific examples of organic compounds having electron-withdrawing groups and a LUMO energy level of -4.5 eV or higher and -3.0 eV or lower include the aforementioned PPDN, HAT-CN, HATNA-F6, etc. Note that organic compounds having electron-withdrawing groups and a LUMO energy level of -4.5 eV or higher and -3.0 eV or lower that can be used in buffer layer 220 are not limited to these.

[0163] <Second Carrier Transport Layer> The second carrier transport layer 214 is a layer that transports electrons provided by the buffer layer 220 to the second electrode 202, and contains an electron transport material. The electron transport material is preferably a material with an electron mobility of 1×10⁻⁶ cm² / Vs or higher. Furthermore, any material other than the one described above can be used as long as its electron transport capability is higher than its hole transport capability. In this specification, the second carrier transport layer is sometimes referred to as an electron transport layer.

[0164] As an electron transport material, π-deficient heteroaromatic compounds can be used.

[0165] In addition, as electron transport materials, metal complexes containing a quinoline skeleton, metal complexes containing a benzoquinoline skeleton, metal complexes containing a chloroazole skeleton, metal complexes containing a thiazole skeleton, metal complexes containing a diazole derivative, triazole derivative, imidazole derivative, chloroazole derivative, thiazole derivative, phenoline derivative, quinoline derivatives containing a quinoline ligand, benzoquinoline derivatives, quinoline derivatives, dibenzoquinoline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other nitrogen-containing heteroaromatic compounds, etc., are π-electron-deficient heteroaromatic compounds.

[0166] Alternatively, the electron transport material is a compound containing a triazine ring.

[0167] Alternatively, the electron transport material is an organic compound represented by the following general formula (Ge-1).

[0168] [Chemical Formula 49]

[0169] In the above general formula (Ge-1), Ar1 to Ar3 independently represent hydrogen, an aryl group with 6 or more but less than 30 substituted or unsubstituted carbon atoms, or a heteroaryl group with 2 to 30 substituted or unsubstituted carbon atoms, respectively. X1 and X2 independently represent carbon or nitrogen. When one or both of X1 and X2 are carbon, carbon is bonded to hydrogen, an aryl group with 6 or more but less than 30 substituted or unsubstituted carbon atoms, a heteroaryl group with 2 to 30 substituted or unsubstituted carbon atoms, an alkyl group with 1 to 20 substituted or unsubstituted carbon atoms, or a cycloalkyl group with 1 to 20 substituted or unsubstituted carbon atoms.

[0170] Alternatively, the electron transport material is an organic compound represented by the following general formula (Ge-2).

[0171] [Chemical Formula 50]

[0172] In the above general formula (Ge-2), Ar1 to Ar3 independently represent hydrogen, an aryl group with 6 or more but less than 30 substituted or unsubstituted carbon atoms, or a heteroaryl group with 2 to 30 substituted or unsubstituted carbon atoms, respectively. X2 represents carbon or nitrogen. When X2 is carbon, carbon is bonded to hydrogen, an aryl group with 6 or more but less than 30 substituted or unsubstituted carbon atoms, a heteroaryl group with 2 to 30 substituted or unsubstituted carbon atoms, an alkyl group with 1 to 20 substituted or unsubstituted carbon atoms, or a cycloalkyl group with 1 to 20 substituted or unsubstituted carbon atoms.

[0173] Alternatively, the electron transport material is an organic compound represented by the following general formula (Ge-3).

[0174] [Chemical Formula 51]

[0175] In the above general formula (Ge-3), Ar1 to Ar3 independently represent hydrogen, an aryl group with 6 or more but less than 30 substituted or unsubstituted carbon atoms, or a heteroaryl group with 2 to 30 substituted or unsubstituted carbon atoms.

[0176] Alternatively, the electron transport material is an organic compound represented by the following general formula (Ge-4).

[0177] [Chemical Formula 52]

[0178] In the above general formula (Ge-4), Ar3 represents hydrogen, an aryl group having 6 or more but less than 30 substituted or unsubstituted carbon atoms, or a heteroaryl group having 2 to 30 substituted or unsubstituted carbon atoms, and R1 to R10 represent hydrogen, an alkyl group having 1 to 20 substituted or unsubstituted carbon atoms, a cycloalkyl group having 3 to 20 substituted or unsubstituted carbon atoms, an aryl group having 6 or more but less than 30 substituted or unsubstituted carbon atoms, or a heteroaryl group having 2 to 30 substituted or unsubstituted carbon atoms, respectively.

[0179] R1 to R10 in the above general formula (Ge-4) not only represent the above substituents, but also represent halogens, substituted or unsubstituted alkyl halides with 1 to 13 carbon atoms, cyano groups, substituted or unsubstituted alkoxy groups with 1 to 13 carbon atoms.

[0180] R1 to R10 in the above general formula (Ge-4) are preferably substituents represented by formulas (R-1) to (R-38), substituents represented by formulas (R-41) to (R-116) and substituents represented by formulas (R-118) to (R-131).

[0181] Furthermore, Ar1 to Ar3 in the above general formulas (Ge-1) to (Ge-3) and Ar3 in the above general formula (Ge-4) are preferably substituents represented by formulas (R-41) to (R-116) and substituents represented by formulas (R-118) to (R-131).

[0182] [Chemical Formula 53]

[0183] [Chemical Formula 54]

[0184] [Chemical Formula 55]

[0185] [Chemical Formula 56]

[0186] [Chemical Formula 57]

[0187] [Chemical Formula 58]

[0188] Next, specific examples of electron transport materials having the above-described structures are shown below.

[0189] [Chemical Formula 59]

[0190] [Chemical Formula 60]

[0191] The organic compounds represented by the above structural formulas (500) to (524) are examples of organic compounds represented by the above general formulas (Ge-1) to (Ge-4), but specific examples of electron transport materials are not limited thereto.

[0192] In addition, organic compounds represented by the following structural formulas (600) to (622) can be used as electron transport materials.

[0193] [Chemical Formula 61]

[0194] [Chemical Formula 62]

[0195] In addition, the second carrier transport layer 214 may also be formed using the material of the electron transport layer 114 that can be used in a light-emitting device, as described in Embodiment 2.

[0196] Furthermore, the second carrier transport layer 214 may have a single-layer structure or a stacked structure consisting of two or more layers made of the aforementioned material.

[0197] <Second Carrier Injection Layer> The second carrier injection layer 215 is a layer used to improve the efficiency of electron injection from the light-receiving layer 203 to the second electrode 202, and contains a material with high electron injection performance. Alkali metals, alkaline earth metals, or compounds containing the above substances can be used as the material with high electron injection performance. Composite materials containing both electron transport materials and donor materials (electron donor materials) can also be used as the material with high electron injection performance. In this specification, the second carrier injection layer is sometimes referred to as the electron injection layer.

[0198] The second carrier injection layer 215 can be formed using the material that can be used for the electron injection layer 115 of the light-emitting device, which will be described in Embodiment 2.

[0199] Furthermore, by providing a charge generation layer between two light-receiving layers 203, a structure in which multiple light-receiving layers are stacked between a pair of electrodes can be obtained (also known as a series structure). Furthermore, by providing a charge generation layer between different light-receiving layers, a stacked structure with three or more light-receiving layers can be obtained. The charge generation layer can be formed using the material of the charge generation layer 106 for use in a light-emitting device, as described in Embodiment 2.

[0200] The materials used in each layer (first carrier injection layer 211, first carrier transport layer 212, active layer 213, second carrier transport layer 214, second carrier injection layer 215) constituting the light-receiving layer 203 of the light-receiving device shown in this embodiment are not limited to the materials shown in this embodiment. Other materials may be used in combination as long as they meet the functions of each layer.

[0201] In this specification, the terms "layer" and "film" may be interchanged.

[0202] A light-receiving device according to one embodiment of the present invention has the function of detecting visible light. Furthermore, the light-receiving device according to one embodiment of the present invention is sensitive to visible light. Furthermore, the light-receiving device according to one embodiment of the present invention preferably has the function of detecting both visible light and infrared light. Furthermore, the light-receiving device according to one embodiment of the present invention preferably has sensitivity to both visible light and infrared light.

[0203] Note that in this specification, the wavelength region of blue (B) refers to 400 nm or more and less than 490 nm, and blue (B) light has at least one emission spectral peak in this wavelength region. Furthermore, the wavelength region of green (G) refers to 490 nm or more and less than 580 nm, and green (G) light has at least one emission spectral peak in this wavelength region. Furthermore, the wavelength region of red (R) refers to 580 nm or more and less than 750 nm, and red (R) light has at least one emission spectral peak in this wavelength region. Furthermore, in this specification, the wavelength region of visible light refers to 400 nm or more and less than 750 nm, and visible light has at least one emission spectral peak in this wavelength region. Furthermore, the wavelength region of infrared (IR) refers to 700 nm or more and less than 900 nm, and infrared (IR) light has at least one emission spectral peak in this wavelength region.

[0204] The light-receiving device of one embodiment of the present invention described above can be applied to 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. Furthermore, in other words, in a light-emitting device including an organic EL device and a light-receiving device, the light-receiving device of one embodiment of the present invention can be used as the light-receiving device. As an example, FIG2A is a schematic cross-sectional view of a light-emitting device 810 in which a light-emitting device 805a and a light-receiving device 805b are formed on the same substrate.

[0205] Because the light-emitting device 810 includes a light-emitting device 805a and a light-receiving device 805b, it not only has the function of displaying images, but also has one or both of the functions of shooting and sensing.

[0206] The light-emitting device 805a has the function of emitting light (hereinafter also referred to as light-emitting function). The light-emitting device 805a includes an electrode 801a, an EL layer 803a, and an electrode 802. The EL layer 803a sandwiched between the electrode 801a and the electrode 802 includes at least a light-emitting layer. The light-emitting layer contains a light-emitting material. By applying a voltage between the electrode 801a and the electrode 802, light is emitted from the EL layer 803a. In addition to the light-emitting layer, the EL layer 803a may also include various layers such as a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a carrier (hole or electron) barrier layer, and a charge generation layer. As the light-emitting device 805a, the structure of the light-emitting device, which is the organic EL device described in Embodiment 2, can be applied.

[0207] The light-receiving device 805b has the function of detecting light (hereinafter also referred to as the light-receiving function). The light-receiving device 805b includes 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 includes at least an active layer. The light-receiving device 805b is used as a photoelectric conversion device, and can generate charge by light incident on the light-receiving layer 803b, thereby extracting it as current. At this time, a voltage can also be applied between the electrode 801b and the electrode 802. The amount of charge generated depends on the amount of light incident on the light-receiving layer 803b. The structure of the light-receiving device 200 described above can be used as the light-receiving device 805b.

[0208] The light-receiving device 805b is easy to make thin, lightweight and large-area, and its shape and design are highly flexible, so it can be applied to a wide variety of display devices. In addition, the EL layer 803a included in the light-emitting device 805a and the light-receiving layer 803b included in the light-receiving device 805b can be formed using the same method (e.g., vacuum evaporation), and can share the same manufacturing equipment, which is therefore preferable.

[0209] Electrodes 801a and 801b are disposed on the same surface. Figure 2A shows the structure of electrodes 801a and 801b disposed on substrate 800. Note that electrodes 801a and 801b can be formed, for example, by processing a conductive film formed on substrate 800 into an island shape. That is, electrodes 801a and 801b can be formed by the same process.

[0210] The substrate 800 can be a substrate with heat resistance capable of withstanding the formation of the light-emitting device 805a and the light-receiving device 805b. When using an insulating substrate as the substrate 800, glass substrates, quartz substrates, sapphire substrates, ceramic substrates, organic resin substrates, etc., can be used. In addition, single-crystal semiconductor substrates or polycrystalline semiconductor substrates made of materials such as silicon or silicon carbide, compound semiconductor substrates made of materials such as silicon and germanium, SOI substrates, etc., can also be used.

[0211] In particular, the substrate 800 is preferably a substrate on which a semiconductor circuit including semiconductor elements such as transistors is formed on the aforementioned insulating substrate or semiconductor substrate. This semiconductor circuit is preferably, for example, a pixel circuit, a gate line drive circuit (gate driver), a source line drive circuit (source driver), etc. Furthermore, in addition to the above, it can also be configured as an arithmetic circuit, a memory circuit, etc.

[0212] Furthermore, electrode 802 is an electrode composed of a layer commonly used in light-emitting device 805a and light-receiving device 805b. The electrodes on the light-emitting or light-incident side of electrodes 801a, 801b, and 802 use conductive films that transmit visible and infrared light. The electrodes on the side that do not emit or receive light preferably use conductive films that reflect visible and infrared light.

[0213] In one embodiment of the present invention, the electrode 802 of the light-receiving device is used as an electrode of each of the light-emitting device 805a and the light-receiving device 805b.

[0214] Figure 2B shows the case where the potential of electrode 801a of the light-emitting device 805a is higher than that of electrode 802. In this case, electrode 801a is used as the anode of the light-emitting device 805a, and electrode 802 is used as the cathode. Furthermore, the potential of electrode 801b of the light-receiving device 805b is lower than that of electrode 802. Note that in Figure 2B, to easily understand the direction of current flow, the circuit symbol of the light-emitting diode is shown on the left side of the light-emitting device 805a, and the circuit symbol of the photodiode is shown on the right side of the light-receiving device 805b. Furthermore, the direction of carrier (electron and hole) flow is schematically indicated by arrows in each device.

[0215] In the structure shown in FIG2B, when electrode 801a is supplied with a first potential through the first wiring, electrode 802 is supplied with a second potential through the second wiring, and electrode 801b is supplied with a third potential through the third wiring, the magnitude relationship of each potential satisfies the condition that the first potential > the second potential > the third potential.

[0216] Figure 2C shows the case where the potential of electrode 801a of the light-emitting device 805a is lower than that of electrode 802. In this case, electrode 801a is used as the cathode of the light-emitting device 805a, and electrode 802 is used as the anode. Furthermore, the potential of electrode 801b of the light-receiving device 805b is lower than that of electrode 802 and higher than that of electrode 801a. Note that in Figure 2C, to easily understand the direction of current flow, the circuit symbol of the light-emitting diode is shown on the left side of the light-emitting device 805a, and the circuit symbol of the photodiode is shown on the right side of the light-receiving device 805b. Furthermore, the direction of carrier (electron and hole) flow is schematically indicated by arrows in each device.

[0217] In the structure shown in FIG2C, when electrode 801a is supplied with a first potential through the first wiring, electrode 802 is supplied with a second potential through the second wiring, and electrode 801b is supplied with a third potential through the third wiring, the magnitude relationship of each potential satisfies the condition that the second potential > the third potential > the first potential.

[0218] FIG3A shows a modified example of a light-emitting device 810A, which is a light-emitting device 810. The difference between light-emitting device 810A and light-emitting device 810 is that light-emitting device 810A includes a common layer 806 and a common layer 807. In light-emitting device 805a, common layers 806 and 807 are used as part of EL layer 803a. Furthermore, in light-receiving device 805b, common layers 806 and 807 are used as part of light-receiving layer 803b. Furthermore, common layer 806 includes, for example, a hole injection layer and a hole transport layer. Furthermore, common layer 807 includes, for example, an electron transport layer and an electron injection layer.

[0219] By adopting a structure with a common layer 806 and a common layer 807, a light-receiving device can be built in without significantly increasing the number of separate coatings, thereby enabling the light-receiving device 810A to be manufactured with high productivity.

[0220] Figure 3B shows a modified example of the light-receiving device 810B. The difference between the light-receiving device 810B and the light-receiving device 810 is that in the light-receiving device 810B, the EL layer 803a includes layers 806a and 807a, and the light-receiving layer 803b includes layers 806b and 807b. Layers 806a and 806b are made of different materials, for example, including a hole injection layer and a hole transport layer. Alternatively, layers 806a and 806b may be made of a common material. Similarly, layers 807a and 807b are made of different materials, for example, including an electron transport layer and an electron injection layer. Alternatively, layers 807a and 807b may be made of a common material.

[0221] By selecting the most suitable material for constituting the light-emitting device 805a and using it in layers 806a and 807a, and by selecting the most suitable material for constituting the light-receiving device 805b and using it in layers 806b and 807b, the performance of the light-emitting device 805a and the light-receiving device 805b can be improved in the light-emitting device 810B.

[0222] Note that the resolution of the light-receiving device 805b can be 100 ppi or higher, preferably 200 ppi or higher, more preferably 300 ppi or higher, further preferably 400 ppi or higher, and even more preferably 500 ppi or higher, but can be 2000 ppi or lower, 1000 ppi or lower, or 600 ppi or lower. In particular, by configuring the light-receiving device 805b with a resolution of 200 ppi or higher and 600 ppi or lower, preferably 300 ppi or higher and 600 ppi or lower, it can be appropriately used for fingerprint imaging. When using the light-receiving device 810 for fingerprint recognition, by improving the resolution of the light-receiving device 805b, for example, the fingerprint's feature points (minutia) can be extracted with high precision, thereby improving the accuracy of fingerprint recognition. Furthermore, a resolution of 500 ppi or higher can meet the specifications of the National Institute of Standards and Technology (NIST), etc., and is therefore preferred. Note that with a resolution of 500ppi for the light-receiving device, the size of each pixel is 50.8μm, indicating that this resolution is sufficient to capture the spacing of fingerprint ridges (typically above 300μm and below 500μm).

[0223] The structure shown in this embodiment can be used in appropriate combination with the structures shown in other embodiments.

[0224] Embodiment 2 In this embodiment, other structures of the light-emitting device shown in Embodiment 1 will be described with reference to FIGS. 4A to 4E.

[0225] <<Basic Structure of Light-Emitting Devices>> The basic structure of a light-emitting device will be described. Figure 4A shows a light-emitting device with an EL layer having a light-emitting layer between a pair of electrodes. Specifically, an EL layer 103 is included between the first electrode 101 and the second electrode 102.

[0226] Figure 4B shows a light-emitting device with a stacked structure (series structure) including multiple (two layers in Figure 4B) EL layers (103a, 103b) between a pair of electrodes and a charge generation layer 106 between the EL layers. The light-emitting device with the series structure can realize a light-emitting device that can be driven by low voltage and has low power consumption.

[0227] The charge generation layer 106 has the following function: when a potential difference is generated between the first electrode 101 and the second electrode 102, it injects electrons into one EL layer (103a or 103b) and injects holes into the other EL layer (103b or 103a). Thus, in FIG4B, when a voltage is applied in such a way that the potential of the first electrode 101 is higher than that of the second electrode 102, the charge generation layer 106 injects electrons into the EL layer 103a and injects holes into the EL layer 103b.

[0228] Furthermore, from the viewpoint of light extraction efficiency, the charge generation layer 106 is preferably transparent to visible light (specifically, the visible light transmittance of the charge generation layer 106 is 40% or more). In addition, it functions even if the conductivity of the charge generation layer 106 is lower than that of the first electrode 101 and the second electrode 102.

[0229] FIG4C shows the stacked structure of the EL layer 103 of a light-emitting device according to an embodiment of the present invention. Note that in this case, the first electrode 101 is used as the anode and the second electrode 102 is used as the 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 on the first electrode 101. Note that the light-emitting layer 113 may also be stacked with multiple light-emitting layers of different emitting colors. For example, a light-emitting layer containing a light-emitting material emitting red light, a light-emitting layer containing a light-emitting material emitting green light, and a light-emitting layer containing a light-emitting material emitting blue light may be stacked with or without separation from layers containing carrier transport materials. Alternatively, a light-emitting layer containing a light-emitting material emitting yellow light and a light-emitting layer containing a light-emitting material emitting blue light may be combined. Note that the stacked structure of the light-emitting layer 113 is not limited to the above structure. For example, the light-emitting layer 113 may also be stacked with multiple light-emitting layers of the same emitting color. For example, a first luminescent layer containing a blue light-emitting material and a second luminescent layer containing a blue light-emitting material can be stacked with or without separation between layers containing carrier transport materials. When multiple luminescent layers of the same color are stacked, reliability can sometimes be improved compared to a single layer. Furthermore, in the series structure shown in FIG4B, which includes multiple EL layers, each EL layer is stacked sequentially from the anode side as described above. Additionally, when the first electrode 101 is the cathode and the second electrode 102 is the anode, the stacking order of the EL layers 103 is reversed. Specifically, on the first electrode 101 of the cathode, 111 is the electron injection layer, 112 is the electron transport layer, 113 is the luminescent layer, 114 is the hole transport layer, and 115 is the hole injection layer.

[0230] The luminescent layer 113 in the EL layers (103, 103a, and 103b) can be appropriately combined with luminescent materials and multiple materials to obtain fluorescence or phosphorescence that exhibits the desired emission color. Furthermore, the luminescent layer 113 may also have a stacked structure with different emission colors. In this case, different materials can be used as one or two of the luminescent materials and other materials used in each of the stacked luminescent layers. Alternatively, a structure can be adopted in which different emission colors are obtained from multiple EL layers (103a and 103b) as shown in FIG. 4B. In this case, different materials can be used as one or two of the luminescent materials and other materials used in each luminescent layer.

[0231] Furthermore, in a light-emitting device according to one embodiment of the present invention, for example, by making the first electrode 101 shown in FIG4C a reflective electrode, making the second electrode 102 a semi-transmissive-semi-reflective electrode and adopting an optical microcavity resonator (microcavity) structure, the light obtained from the light-emitting layer 113 in the EL layer 103 can resonate between the electrodes, thereby enhancing the light obtained through the second electrode 102.

[0232] When the first electrode 101 of the light-emitting device is a reflective electrode composed of a stacked structure of a reflective conductive material and a light-transmitting conductive material (transparent conductive film), optical adjustment can be performed by controlling the thickness of the transparent conductive film. Specifically, it is preferable to adjust it in such a way that when the wavelength of the light obtained from the light-emitting layer 113 is λ, the optical distance (product of thickness and refractive index) between the first electrode 101 and the second electrode 102 is mλ / 2 (note that m is a natural number) or a value close to it.

[0233] 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 can be 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 can be obtained, both to be (2m'+1)λ / 4 (note that m' is a natural number) or a value close to that. Note that the "light-emitting region" described here refers to the recombination region of holes and electrons in the light-emitting layer 113.

[0234] By performing the above optical adjustments, the spectrum of the specific monochromatic light that can be obtained from the light-emitting layer 113 can be narrowed, thereby obtaining light emission with good color purity.

[0235] Furthermore, in the above-described case, strictly speaking, the optical distance between the first electrode 101 and the second electrode 102 can be considered as the total thickness from the reflective region in the first electrode 101 to the reflective region in the second electrode 102. However, since it is difficult to accurately determine the positions of the reflective regions in the first electrode 101 and the second electrode 102, the above-described effect can be sufficiently obtained by assuming any position in the first electrode 101 and the second electrode 102 as a reflective region. Furthermore, strictly speaking, the optical distance between the first electrode 101 and the light-emitting layer from which the desired light is obtained can be considered as the optical distance between the reflective region in the first electrode 101 and the light-emitting region in the light-emitting layer from which the desired light is obtained. However, since it is difficult to accurately determine the positions of the reflective region in the first electrode 101 and the light-emitting region in the light-emitting layer from which the desired light is obtained, the above-described effect can be sufficiently obtained by assuming any position in the first electrode 101 as a reflective region and any position in the light-emitting layer from which the desired light is obtained as a light-emitting region.

[0236] The light-emitting device shown in Figure 4D is a series-connected light-emitting device with a microcavity structure, so different wavelengths of light (monochromatic light) can be extracted from each EL layer (103a, 103b). Therefore, it is not necessary to separately coat the layers (e.g., R, G, B) to obtain different emission colors. This allows for easy achievement of high resolution. Furthermore, it can be combined with color layers (color filters). Moreover, the emission intensity in the front direction at a specific wavelength can be enhanced, thereby achieving low power consumption.

[0237] The light-emitting device shown in Figure 4E is an example of the series-connected structure of the light-emitting device shown in Figure 4B. As shown in the figure, it has a structure in which three EL layers (103a, 103b, 103c) are stacked with charge-generating layers (106a, 106b) sandwiched between them. The three EL layers (103a, 103b, 103c) each include a light-emitting layer (113a, 113b, 113c), and the light-emitting colors of each light-emitting layer can be freely combined. For example, light-emitting layers 113a and 113c can be blue, and light-emitting layer 113b can be red, green, or yellow. Furthermore, for example, light-emitting layers 113a and 113c can be red, and light-emitting layer 113b can be blue, green, or yellow.

[0238] Furthermore, in the light-emitting device of one embodiment of the present invention described above, at least one of the first electrode 101 and the second electrode 102 is a light-transmitting electrode (transparent electrode, semi-transmissive-semi-reflective electrode, etc.). When the light-transmitting electrode is a transparent electrode, the visible light transmittance of the transparent electrode is 40% or more. Furthermore, when the electrode is a semi-transmissive-semi-reflective electrode, the visible light reflectance of the semi-transmissive-semi-reflective electrode is 20% or more and 80% or less, preferably 40% or more and 70% or less. Furthermore, the resistivity of these electrodes is preferably 1 × 10⁻² Ωcm or less.

[0239] Furthermore, in the light-emitting device of one embodiment of the present invention described above, when one of the first electrode 101 and the second electrode 102 is a reflective electrode (reflective electrode), the visible light reflectance of the reflective electrode is 40% or more and 100% or less, preferably 70% or more and 100% or less. Furthermore, the resistivity of the electrode is preferably 1 × 10⁻² Ωcm or less.

[0240] <<Specific Structure of the Light-Emitting Device>> Next, the specific structure of a light-emitting device according to one embodiment of the present invention will be described. Referring here to FIG. 4D, which has a series structure, the description will be made accordingly. Note that the light-emitting devices with a single structure shown in FIGS. 4A and 4C also have the same EL layer structure. Furthermore, in the case where the light-emitting device shown in FIG. 4D has a microcavity structure, a reflective electrode is formed as the first electrode 101, and a semi-transmissive-semi-reflective electrode is formed as the second electrode 102. Thus, the electrodes can be formed in a single layer or in a stack using a desired electrode material alone or using multiple electrode materials. Furthermore, the second electrode 102 is formed after the EL layer 103b is formed, using the same material as described above.

[0241] <First Electrode and Second Electrode> The materials used to form the first electrode 101 and the second electrode 102 can be appropriately combined as long as they can satisfy the functions of the two electrodes. For example, metals, alloys, conductive compounds, and mixtures thereof can be appropriately used. Specifically, examples include In-Sn oxide (also known as ITO), In-Si-Sn oxide (also known as ITSO), In-Zn oxide, and In-W-Zn oxide. In addition to the above, metals such as aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), and neodymium (Nd), as well as alloys appropriately combined therein, can also be used. In addition to the above, elements belonging to Group 1 or Group 2 of the periodic table (e.g., rare earth metals such as lithium (Li), cesium (Cs), calcium (Ca), strontium (Sr)), europium (Eu), ytterbium (Yb), alloys of them appropriately combined, and graphene, etc., can be used.

[0242] In the light-emitting device shown in FIG4D, when the first electrode 101 is the anode, the hole injection layer 111a and the hole transport layer 112a of the EL layer 103a are sequentially deposited on the first electrode 101 by vacuum evaporation. 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 sequentially deposited on the charge generation layer 106 in the same manner as described above.

[0243] <Hole Injection Layer> The hole injection layer (111, 111a, 111b) is a layer in which holes are injected from the first electrode 101 of the anode or the charge generation layer (106, 106a, 106b) into the EL layer (103, 103a, 103b), and contains organic acceptor materials and materials with high hole injection properties.

[0244] Organic acceptor materials can generate holes in organic compounds by charge separation between them and other organic compounds whose LUMO energy level is close to the HOMO energy level. Therefore, compounds with electron-withdrawing groups (halogen or cyano groups), such as quinone dimethane derivatives, tetrachlorobenzoquinone derivatives, and hexaazatribenzene derivatives, can be used as organic acceptor materials. For example, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinone dimethyl ether (abbreviated as F4-TCNQ), 3,6-difluoro-2,5,7,7,8,8-hexacyano-p-quinone dimethyl ether, chloroquinone, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatribenzene (abbreviated as HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinone dimethyl ether (abbreviated as F6-TCNNQ), and 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyrene-2-ylidene)malonitrile can be used. In organic acceptor materials, compounds such as HAT-CN with electron-withdrawing groups bonded to fused aromatic rings with multiple heteroatoms have high acceptor properties and thermal stability, making them particularly superior. In addition, [3] axylene derivatives with electron-withdrawing groups (especially halogen groups such as fluorine groups or cyano groups) have very high electron acceptor properties and are therefore superior. Specifically, the following can be used: α,α',α''-1,2,3-cyclopropanetrimethylenetri[4-cyano-2,3,5,6-tetrafluorophenylacetonitrile], α,α',α''-1,2,3-cyclopropanetrimethylenetri[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)phenylacetonitrile], α,α',α''-1,2,3-cyclopropanetrimethylenetri[2,3,4,5,6-pentafluorophenylacetonitrile], etc.

[0245] As a material with high hole injection capability, oxides of metals belonging to Groups 4 to 8 of the periodic table (such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, manganese oxide, and other transition metal oxides) can be used. Specifically, examples include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among these, molybdenum oxide is particularly preferred because it is stable in the atmosphere, has low hygroscopicity, and is easy to handle. In addition to the above, phthalocyanine compounds such as phthalocyanine (abbreviated as H2Pc) and phthalocyanine bronze (CuPc) can be used.

[0246] In addition to the materials mentioned above, aromatic amine compounds of low molecular weight compounds such as 4,4',4''-tris(N,N-diphenylamino)triphenylamine (abbreviated as TDATA), 4,4',4''-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviated as MTDATA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as DPAB), N-N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl) 4,4'-diamine (abbreviated as DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviated as DPA3B), 3-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviated as PCzPCA1), 3,6-bis[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviated as PCzPCA2), 3-[N-(1-naphthyl)-N-(9-phenylcarbazole-3-yl)amino]-9-phenylcarbazole (abbreviated as PCzPCN1), etc.

[0247] In addition, polymeric compounds (oligomers, dendritic polymers, or polymers, etc.) can be used, such as poly(N-vinylcarbazole) (abbreviated as PVK), poly(4-vinyltriphenylamine) (abbreviated as PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviated as PTPDMA), poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviated as Poly-TPD), etc. Alternatively, polymeric compounds containing acids can be used, such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (abbreviated as PEDOT / PSS), polyaniline / poly(styrenesulfonic acid) (PAni / PSS), etc.

[0248] As a material with high hole injection capability, a hybrid material comprising a hole transport material and the aforementioned organic acceptor material (electron acceptor material) may also be used. In this case, electrons are extracted from the hole transport material by the organic acceptor material to generate a hole in the hole injection layer 111, and the hole is injected into the light-emitting layer 113 via the hole transport layer 112. Furthermore, the hole injection layer 111 may be a single layer composed of a hybrid material comprising a hole transport material and an organic acceptor material (electron acceptor material), or it may be a stack of layers formed using a hole transport material and an organic acceptor material (electron acceptor material) respectively.

[0249] As a hole transport material, it is preferable to use a material with a hole mobility of 1×10⁻⁶ cm² / Vs or higher when the square root of the electric field strength [V / cm] is 600. In addition, any material other than the above-mentioned material may be used as long as its hole transport is higher than its electron transport.

[0250] As a hole transport material, it is preferable to use a compound with a π-electron-rich heteroaromatic ring (e.g., carbazole derivatives, furan derivatives, thiophene derivatives, etc.) or an aromatic amine (an organic compound containing an aromatic amine skeleton) or other materials with high hole transport properties.

[0251] As the above-mentioned carbazole derivatives (organic compounds having a carbazole ring), examples include bicarbazole derivatives (e.g., 3,3'-bicarbazole derivatives) and aromatic amines having a carbazole group.

[0252] Specifically, examples of the above-mentioned bicarbazole derivatives (e.g., 3,3'-bicarbazole derivatives) include 3,3'-bis(9-phenyl-9H-carbazole) (abbreviated as PCCP), 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviated as BisBPCz), 9,9'-bis(1,1'-biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviated as BisBPCz), 9-(1,1'-biphenyl-3-yl)-9'-(1,1'-biphenyl-4-yl)-9H,9'H-3,3'-bicarbazole (abbreviated as mBPCCBP), and 9-(2-naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviated as βNCCP), etc.

[0253] In addition, as the above-mentioned aromatic amines having a carbazole group, examples specifically include 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCBA1BP), N-(4-biphenyl)-N-(9,9-dimethyl-9H-enazol-2-yl)-9-phenyl-9H-carbazole-3-amine (abbreviated as: PCBiF), N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-enazol-2-amine (abbreviated as: PCBBiF), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCBi1BP), 4-(1-naphthalene) 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCCNBB), 4-phenyldiphenyl-(9-phenyl-9H-carbazole-3-yl)amine (abbreviation: PCA1BP), N,N'-bis(9-phenylcarbazole-3-yl)-N,N'-diphenylphenyl-1,3-diamine (abbreviation: PCA2B), N,N',N''-triphenyl-N,N',N''-tri(9-phenylcarbazole-3-yl)phenyl-1,3,5-triamine (abbreviation: PCA3B), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl- 9H-carbazole-3-yl)phenyl]furan-2-amine (abbreviated as: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]spiro-9,9'-difuran-2-amine (abbreviated as: PCBASF), 3-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviated as: PCzPCA1), 3,6-bis[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviated as: PCzPCA2), 3-[N-(1-naphthyl)-N-(9-phenylcarbazole-3-yl)amino]-9-phenylcarbazole (abbreviated as: PCzPCN1), 3-[N-(4-diphenylaminophenyl)-N-phenylamino]-N-phenylamino 3,6-Bis[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (PCzDPA2), 3,6-Bis[N-(4-diphenylaminophenyl)-N-(1-naphthyl)amino]-9-phenylcarbazole (PCzTPN2), 2-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]spiro-9,9'-diphenylcarbazole (PCASF), N-[4-(9H-carbazole-9-yl)phenyl]-N-(4-phenyl)phenylaniline (YGA1BP), N,N'-bis[4-(carbazole-9-yl)phenyl]-N,N'-diphenyl-9,9-dimethylcarbazole-2,7-Diamine (abbreviated as YGA2F), 4,4',4''-tris(carbazole-9-yl)triphenylamine (abbreviated as TCTA), etc.

[0254] Note that, in addition to the above, other examples of carbazole derivatives include 3-[4-(9-phenanthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPPn), 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPN), 1,3-bis(N-carbazolyl)benzene (abbreviated as mCP), 4,4'-bis(N-carbazolyl)biphenyl (abbreviated as CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviated as CzTP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviated as TCPB), and 9-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole (abbreviated as CzPA), etc.

[0255] Specifically, examples of the above-mentioned furan derivatives (organic compounds having a furan ring) include 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzofuran) (abbreviated as: DBF3P-II) and 4-{3-[3-(9-phenyl-9H-en-9-yl)phenyl]phenyl}dibenzofuran (abbreviated as: mmDBFFLBi-II).

[0256] Specifically, examples of the above-mentioned thiophene derivatives (organic compounds having a thiophene ring) include 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzothiophene) (abbreviated as: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-en-9-yl)phenyl]dibenzothiophene (abbreviated as: DBTFLP-III), and 4-[4-(9-phenyl-9H-en-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as: DBTFLP-IV), etc., which have a thiophene ring.

[0257] Specifically, examples of the aforementioned aromatic amines include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as: NPB or α-NPD), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviated as: TPD), 4,4'-bis[N-(spiro-9,9'-dien-2-yl)-N-phenylamino]biphenyl (abbreviated as: BSPB), 4-phenyl-4'-(9-phenylenen-9-yl)triphenylamine (abbreviated as: BPAFLP), 4-phenyl-3'-(9-phenylenen-9-yl)triphenylamine (abbreviated as: mBPAFLP), N-(4-biphenyl)-N-{4-[(9- N,N,N',N'-tetra(4-biphenyl)-1,1-biphenyl-4,4'-diamine (abbreviation: FBiFLP), N,N-bis(9,9-dimethyl-9H-bifen-2-yl)-9,9'-spirodi[9H-bifen]-4-amine (abbreviation: SF4FAF), N-(9,9-dimethyl-9H-bifen-2-yl)-N-{9,9-dimethyl-2-[N'-phenyl-N'-(9,9-dimethyl-9H-bifen-2-yl)amino]-9H-bifen-7-yl}phenylamine (abbreviation: DFLADFL), N-(9,9-dimethyl-9H-bifen-2-yl)amino]-9H-bifen-7-yl}phenylamine (abbreviation: DFLADFL), N-(9,9-dimethyl-9H-bifen-2-yl)amino]-9H-bifen-7-yl}phenylamine (abbreviation: DFLADFL), N-(9,9-dimethyl-9H-bifen-2-yl)amino]-9H-bifen-7-yl}phenylamine 2-Diphenylamino-9H-en-7-yl)diphenylamine (abbreviation: DPNF), 2-[N-(4-diphenylaminophenyl)-N-phenylamino]spiro-9,9'-dienylamine (abbreviation: DPASF), 2,7-bis[N-(4-diphenylaminophenyl)-N-phenylamino]spiro-9,9'-dienylamine (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-MTDA) TA), N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviated: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated: DPAB), DNTPD, 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviated: DPA3B), N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviated: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviated: BBABnf), 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine2-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-(dibenzothiophene-4- [4-(2-naphthyl)phenyl]-N-phenyl-4-benzidine (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'-binathyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binathyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4''-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-) 03), 4,4'-diphenyl-4''-(6;2'-binathyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binathyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binathyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-diphenyl-4''-(5;2'-binathyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4- (3-Biphenyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenyl)-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'-(carbazole-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazole-9-yl)phenyl]tri(1,1'-Biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazole-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), bis-biphenyl-4'-(carbazole-9-yl)biphenylamine (abbreviation: YGBBi1BP), N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi[ 9H-biphenyl]-2-amine (abbreviated as: PCBNBSF), N,N-bis([1,1'-biphenyl]-4-yl)-9,9'-spirobis[9H-biphenyl]-2-amine (abbreviated as: BBASF), N,N-bis([1,1'-biphenyl]-4-yl)-9,9'-spirobis[9H-biphenyl]-4-amine (abbreviated as: BBASF(4)), N-(1,1'-biphenyl-2-yl)-N-(9,9-dimethyl-9H-biphenyl-2-yl)-9,9'-spirobis[ 9H-[fon]-4-amine (abbreviation: oFBiSF), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fon-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-phenylfon-9-yl)phenyl]triphenylamine (abbreviation: BPAFLB) i) N,N-bis(9,9-dimethyl-9H-fumon-2-yl)-9,9'-spirobis-9H-fumon-4-amine, N,N-bis(9,9-dimethyl-9H-fumon-2-yl)-9,9'-spirobis-9H-fumon-3-amine, N,N-bis(9,9-dimethyl-9H-fumon-2-yl)-9,9'-spirobis-9H-fumon-2-amine, N,N-bis(9,9-dimethyl-9H-fumon-2-yl)-9,9'-spirobis-9H-fumon-1-amine, etc.

[0258] In addition, as hole-transporting materials, polymeric compounds (oligomers, dendritic polymers, polymers, etc.) can be used, such as poly(N-vinylcarbazole) (PVK), poly(4-vinyltriphenylamine) (PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (PTPDMA), poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (Poly-TPD), etc. Alternatively, polymeric compounds containing acids can be used, such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (PEDOT / PSS), polyaniline / poly(styrenesulfonic acid) (PAni / PSS), etc.

[0259] Note that the hole transport material is not limited to the above-mentioned materials, and one or more combinations of known materials can be used as the hole transport material.

[0260] Note that the hole injection layers (111, 111a, 111b) can be formed using various known film formation methods, such as vacuum evaporation.

[0261] <Hole Transport Layer> The hole transport layers (112, 112a, 112b) are layers that transport holes injected from the first electrode 101 through the hole injection layers (111, 111a, 111b) to the light-emitting layers (113, 113a, 113b, 113c). Furthermore, the hole transport layers (112, 112a, 112b) are layers containing a hole-transporting material. Therefore, as the hole transport layers (112, 112a, 112b), a hole-transporting material suitable for use in the hole injection layers (111, 111a, 111b) can be used.

[0262] Note that in the light-emitting device according to one embodiment of the present invention, the same organic compound as that used in the hole transport layers (112, 112a, 112b) can be used in the light-emitting layers (113, 113a, 113b, 113c). When the same organic compound is used in both the hole transport layers (112, 112a, 112b) and the light-emitting layers (113, 113a, 113b, 113c), holes can be efficiently transported from the hole transport layers (112, 112a, 112b) to the light-emitting layers (113, 113a, 113b, 113c), which is therefore preferable.

[0263] <Emitting Layer> The emitting layers (113, 113a, 113b, 113c) are layers containing luminescent materials. Materials exhibiting luminescent colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, and red can be appropriately used as luminescent materials for the emitting layers (113, 113a, 113b, 113c). Furthermore, when multiple emitting layers are included, by using different luminescent materials in each emitting layer, a structure exhibiting different luminescent colors can be achieved (for example, white light can be obtained by combining luminescent colors that are complementary colors). Moreover, a stacked structure in which one emitting layer contains different luminescent materials can also be used.

[0264] In addition, the luminescent layers (113, 113a, 113b, 113c) may contain one or more organic compounds (host materials, etc.) in addition to the luminescent material (guest material).

[0265] Note that when multiple host materials are used in the light-emitting layers (113, 113a, 113b, 113c), the newly added second host material is preferably a material with a band gap larger than that of the conventional guest material and the first 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. By employing the above structure, an excited-state complex can be formed from two host materials. Note that for efficient formation of the excited-state complex, it is particularly preferable to combine a compound that readily accepts holes (a hole-transporting material) and a compound that readily accepts electrons (an electron-transporting material). Furthermore, by employing the above structure, high efficiency, low voltage, and long lifetime can be achieved simultaneously.

[0266] Note that, as the organic compounds used as the host materials (including the first host material and the second host material), as long as they meet the conditions for host materials used in the light-emitting layer, organic compounds such as hole-transporting materials that can be used in the hole-transporting layers (112, 112a, 112b) and electron-transporting materials that can be used in the electron-transporting layers (114, 114a, 114b) described later can be used. Exciplexes formed from multiple organic compounds (the first host material and the second host material) can also be used. Furthermore, exciplexes formed from multiple organic compounds in the excited state have the function of converting triple excitation energy into single excitation energy because the difference between the S1 and T1 energy levels is extremely small. As a combination of multiple organic compounds forming exciplexes, it is preferable, for example, that one has a π-electron-deficient heteroaryl ring and the other has a π-electron-rich heteroaryl ring. Furthermore, as one of the combinations forming exciplexes, phosphorescent materials such as iridium, rhodium, platinum-based organometallic complexes or metal complexes can also be used.

[0267] There are no particular restrictions on the luminescent material that can be used in the luminescent layer (113, 113a, 113b, 113c). A luminescent material that converts single excitation energy into light in the visible light region or a luminescent material that converts triple excitation energy into light in the visible light region can be used.

[0268] <<Luminescent Materials that Convert Single Excitation Energy into Light Emission>> Examples of luminescent materials that convert single excitation energy into light emission for use in luminescent layers (113, 113a, 113b, 113c) include fluorescent materials. Examples include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fenestration derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoline derivatives, quinoline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives. Pyrene derivatives, in particular, have a high luminescence quantum yield and are therefore preferred. Specific examples of pyrene derivatives include N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-en-9-yl)phenyl]pyrene-1,6-diamine (abbreviated as: 1,6mMemFLPAPrn), (N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-en-9-yl)phenyl]pyrene-1,6-diamine (abbreviated as: 1,6FLPAPrn), N,N'-bis(dibenzofuran-2-yl)-N,N'-diphenylpyrene-1,6-diamine (abbreviated as: 1,6FrAPrn), and N,N'-bis(dibenzothiophene-2-yl)-N,N '-Diphenylpyrene-1,6-diamine (abbreviated as: 1,6ThAPrn), N,N'-(pyrene-1,6-diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-6-amine] (abbreviated as: 1,6BnfAPrn), N,N'-(pyrene-1,6-diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviated as: 1,6BnfAPrn-02), N,N'-(pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviated as: 1,6BnfAPrn-03), etc.

[0269] In addition, 5,6-bis[4-(10-phenyl-9-anthrayl)phenyl]-2,2'-bipyridine (abbreviated as: PAP2BPy), 5,6-bis[4'-(10-phenyl-9-anthrayl)biphenyl-4-yl]-2,2'-bipyridine (abbreviated as: PAPP2BPy), and N,N'-bis[4-(9H-carbazole-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine can be used. (Abbreviation: YGA2S), 4-(9H-carbazole-9-yl)-4'-(10-phenyl-9-anthrayl)triphenylamine (Abbreviation: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-diphenyl-2-anthrayl)triphenylamine (Abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole-3-amine (Abbreviation: PCAPA), 4- (10-Phenylacetyl)-4'-(9-Phenylacetyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBAPA), 4-[4-(10-Phenylacetyl)phenyl]-4'-(9-Phenylacetyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBAPA), perylene, 2,5,8,11-tetra-tertiary butylperylene (abbreviation: TBP), N,N''-(2-tertiary butylanthracene-9,10-diyldi) N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthrayl)phenyl]-9H-carbazole-3-amine (2PCAPPA), N-[4-(9,10-diphenyl-2-anthrayl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (2DPAPPA), etc.

[0270] In addition, N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthrayl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthrayl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthrayl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), and 9,10-bis(1,1'-biphenyl-2-yl)-N-[4-(9H-carbazole-9-yl)phenyl]-N-phenylanthracene-2-amine (abbreviation: 2YG) can also be used. ABPhA), N,N,9-triphenylanthracene-9-amine (abbreviated as: DPhAPhA), coumarin 545T, N,N'-diphenylquinacridone (abbreviated as: DPQd), fluorene, 5,12-bis(1,1'-biphenyl-4-yl)-6,11-diphenyltetraphenyl (abbreviated as: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]vinyl}-6-methyl-4H-pyran-4-ylidene)malonitrile (abbreviated as: DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinazin-9-yl)vinyl]-4H-pyran-4-ylidene}malonitrile (abbreviated as: DCM2), N,N,N ',N'-Tetra(4-methylphenyl)tetraphenyl-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetra(4-methylphenyl)acenaphthene[1,2-a]propadiene-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]quinazine-9-yl)vinyl]-4H-pyran-4-ylidene}malonium (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]] Quinazine-9-yl)vinyl]-4H-pyran-4-ylidene}malonium (abbreviation: DCJTB), 2-(2,6-bis{2-[4-(dimethylamino)phenyl]vinyl}-4H-pyran-4-ylidene)malonium (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinazine-9-yl)vinyl]-4H-pyran-4-ylidene}malonium (abbreviation: BisDCJTM), 1,6BnfAPrn-03, 3,10-bis[N-(9-phenyl-9H-carbazole-2-yl)-N-phenylamino]naphtho[2,3-b;[6,7-b']bisbenzofuran (abbreviated as: 3,10PCA2Nbf(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-anilino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviated as: 3,10FrA2Nbf(IV)-02), etc. In particular, pyrene diamine compounds such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03 can be used.

[0271] <<Light-emitting material that converts triple excitation energy into light emission>> Next, as a light-emitting material that can be used in the light-emitting layer (113, 113a, 113b, 113c) to convert triple excitation energy into light emission, examples include phosphorescent materials (phosphorescent materials) and thermally activated delayed fluorescence (TADF) materials that exhibit thermally activated delayed fluorescence.

[0272] A phosphorescent material is a compound that emits phosphorescence but not fluorescence at any temperature within a temperature range above low temperature (e.g., 77 K) and below room temperature (i.e., above 77 K and below 313 K). Preferably, the phosphorescent material contains a metallic element with strong spin-orbit interactions, such as organometallic complexes, metal complexes (platinum complexes), rare-earth metal complexes, etc. Specifically, it is preferred to contain a transition metal element, especially platinum group elements (ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), or platinum (Pt)), and particularly preferably iridium. Iridium is preferred because it increases the probability of a direct transition between the singlet ground state and the triplet excited state.

[0273] <<Phosphorescent substances (450nm or more and 570nm or less: blue or green)>> As phosphorescent substances that exhibit blue or green color and whose emission spectrum peak wavelength is 450nm or more and 570nm or less, the following substances can be cited.

[0274] For example, examples include tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviated as: [Ir(mpptz-dmp)3]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazole)iridium(III) (abbreviated as: [Ir(Mptz)3]), and tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazole]iridium(III) (abbreviated as: [Ir(iPrptz-3b)3] Organometallic complexes with a 4H-triazole ring, such as tri[3-(5-biphenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazole]iridium(III) (abbreviated as [Ir(iPr5btz)3]); and organometallic complexes with a 1H-triazole ring, such as tri[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazole]iridium(III) (abbreviated as [Ir(Mptz1-mp)3]) and tri(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazole)iridium(III) (abbreviated as [Ir(Prptz1-Me)3]). Organometallic complexes with rings; organometallic complexes with imidazole rings such as fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazolium]iridium(III) (abbreviated as [Ir(iPrpmi)3]) and tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviated as [Ir(dmpimpt-Me)3]); and bis[2-(4',6'-difluorophenyl)pyridinium-N,C2']iridium(III)tetra(1-pyrazolyl)boronic acid. Organometallic complexes with phenylpyridine derivatives having electron-withdrawing groups as ligands, such as salts (abbreviated as Fir6), bis[2-(4',6'-difluorophenyl)pyridin-N,C2']iridium(III)pyridinecarboxylate (abbreviated as Firpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridin-N,C2'}iridium(III)pyridinecarboxylate (abbreviated as [Ir(CF3ppy)2(pic)]), and bis[2-(4',6'-difluorophenyl)pyridin-N,C2']iridium(III)acetoacetone (abbreviated as Fir(acac)).

[0275] <<Phosphorescent substances (495nm or higher and 590nm or lower: green or yellow)>> As phosphorescent substances that exhibit green or yellow color and whose emission spectrum peak wavelength is 495nm or higher and 590nm or lower, the following substances can be cited.

[0276] For example, tris(4-methyl-6-phenylpyrimidine)iridium(III) can be cited. (Abbreviation: [Ir(mppm)3]), Tris(4-tert-butyl-6-phenylpyrimidine)iridium(III) (Abbreviation: [Ir(tBuppm)3]), (acetylacetone)bis(6-methyl-4-phenylpyrimidine)iridium(III) (Abbreviation: [Ir(mppm)2(acac)]), (acetylacetone)bis(6-tert-butyl-4-phenylpyrimidine)iridium(III) (Abbreviation: [Ir(tBuppm)2(acac)]), (acetylacetone)bis[6-(2-norborneol)-4-phenylpyrimidine]iridium(III) (Abbreviation: [Ir(nbppm)2(acac)]), (acetylacetone)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidine]iridium(III) (Abbreviation: [Ir(mpmppm)2(acac)]) Organometallic iridium complexes with pyrimidine rings, such as (acetyl acetone)bis{4,6-dimethyl-2-[6-(2,6-dimethylphenyl)-4-pyrimidinyl-κN3]phenyl-κC}iridium(III) (abbreviated as [Ir(dmppm-dmp)2(acac)]) and (acetyl acetone)bis(4,6-diphenylpyrimidine)iridium(III) (abbreviated as [Ir(dppm)2(acac)]); organometallic iridium complexes with pyrazine rings, such as (acetyl acetone)bis(3,5-dimethyl-2-phenylpyrazine)iridium(III) (abbreviated as [Ir(mppr-Me)2(acac)]) and (acetyl acetone)bis(5-isopropyl-3-methyl-2-phenylpyrazine)iridium(III) (abbreviated as [Ir(mppr-iPr)2(acac)]);Tris(2-phenylpyridinium-N,C2')iridium(III) (abbreviated as [Ir(ppy)3]), bis(2-phenylpyridinium-N,C2')iridium(III)acetone (abbreviated as [Ir(ppy)2(acac)]), bis(benzo[h]quinoline)iridium(III)acetone (abbreviated as [Ir(bzq)2(acac)]), tris(benzo[h]quinoline)iridium(III) (Abbreviation: [Ir(bzq)3]), Tris(2-phenylquinoline-N,C2')iridium(III) (Abbreviation: [Ir(pq)3]), Bis(2-phenylquinoline-N,C2')iridium(III)acetone (Abbreviation: [Ir(pq)2(acac)]), Bis[2-(2-pyridyl-κN)phenyl-κC][2-(4-phenyl-2-pyridyl-κN)phenyl-κC]iridium(III) (Abbreviation: [Ir(ppy)2) (4dppy)]), bis[2-(2-pyridyl-κN)phenyl-κC][2-(4-methyl-5-phenyl-2-pyridyl-κN)phenyl-κC], [2-d3-methyl-8-(2-pyridyl-κN)benzofuran[2,3-b]pyridyl-κC]bis[2-(5-d3-methyl-2-pyridyl-κN2)phenyl-κC]iridium(III) (abbreviation: Ir(5mppy-d3)2(mbfpypy-d3) [2-(methyl-d3)-8-[4-(1-methylethyl-1-d)-2-pyridyl-κN]benzofurano[2,3-b]pyridin-7-yl-κC]bis[5-(methyl-d3)-2-[5-(methyl-d3)-2-pyridyl-κN]phenyl-κC]iridium(III) (abbreviated as: Ir(5mtpy-d6)2(mbfpypy-iPr-d4)), [2-d3-methyl-(2-pyridyl-κN) Organometallic iridium complexes with pyridine rings, such as benzofuran[2,3-b]pyridine-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviated as: Ir(ppy)2(mbfpypy-d3)) and [2-(4-methyl-5-phenyl-2-pyridyl-κN)phenyl-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviated as: Ir(ppy)2(mdppy)).Organometallic complexes such as bis(2,4-diphenyl-1,3-acetazol-N,C2')iridium(III)acetoacetone (abbreviated as [Ir(dpo)2(acac)]), bis{2-[4'-(perfluorophenyl)phenyl]pyridine-N,C2'}iridium(III)acetoacetone (abbreviated as [Ir(p-PF-ph)2(acac)]), and bis(2-phenylbenzothiazole-N,C2')iridium(III)acetoacetone (abbreviated as [Ir(bt)2(acac)]), and rare earth metal complexes such as tri(acetoacetone-(monoporphyrin)thiazolinium(III) (abbreviated as [Tb(acac)3(Phen)]).

[0277] <<Phosphorescent substances (570nm or higher and 750nm or lower: yellow or red)>> As phosphorescent substances that exhibit yellow or red color and whose emission spectrum peak wavelength is 570nm or higher and 750nm or lower, the following substances can be cited.

[0278] For example, organometallic complexes with pyrimidine rings such as (diisobutylmethane)bis[4,6-bis(3-methylphenyl)pyrimidinium]iridium(III) (abbreviated as: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinium](dineopentylmethane)iridium(III) (abbreviated as: [Ir(5mdppm)2(dpm)]), and (dineopentylmethane)bis[4,6-bis(naphthyl-1-yl)pyrimidinium]iridium(III) (abbreviated as: [Ir(d1npm)2(dpm)]) can be cited; bis(2,3,5-triphenylpyrazine) Iridium (III) (abbreviated as: [Ir(tppr)2(acac)]), bis(2,3,5-triphenylpyrazine)(dineoptidomylmethane)Iridium (III) (abbreviated as: [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-heptanedione-κ2O,O')Iridium (III) (abbreviated as: [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-heptadecyl-κ2O,O')iridium(III) (abbreviated as: [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-heptadecyl-κ2O,O')iridium(III) (abbreviated as: [Ir(dmdppr-dmp)2(dpm)]), (acetylacetone) Organometallic complexes with pyrazine rings, such as bis[2-methyl-3-phenylquinoxalinato]-N,C2']iridium(III) (abbreviated as [Ir(mpq)2(acac)]), (acetylacetone)bis(2,3-diphenylquinoxalinato)-N,C2']iridium(III) (abbreviated as [Ir(dpq)2(acac)]), and (acetylacetone)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviated as [Ir(Fdpq)2(acac)]).Tris(1-phenylisoquinoline-N,C2')iridium(III) (abbreviated as [Ir(piq)3]), bis(1-phenylisoquinoline-N,C2')iridium(III)acetone (abbreviated as [Ir(piq)2(acac)]), bis[4,6-dimethyl-2-(2-quinoline-κN)phenyl-κC] Organometallic complexes with pyridine rings, such as (2,4-pentanedione-κ2O,O')iridium(III) (abbreviated as [Ir(dmpqn)2(acac)]); platinum complexes, such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-violet platinum(II) (abbreviated as [PtOEP]); rare earth metal complexes, such as tris(1,3-diphenyl-1,3-propanedione) europium(III) (abbreviated as [Eu(DBM)3(Phen)]) and tris[1-(2-thiophenecarboxyl)-3,3,3-trifluoroacetone] (abbreviated as [Eu(TTA)3(Phen)]).

[0279] <<TADF Materials>> Furthermore, the following materials can be used as TADF materials. TADF materials refer to materials where the difference between the S1 and T1 energy levels is small (preferably 0.2 eV or less) and can efficiently emit light (fluorescence) from the singlet excited state by up-converting the triplet excited state to a singlet excited state using minimal thermal energy (inverse intersystem crossing). The conditions for efficiently obtaining thermally activated delayed fluorescence are as follows: the energy difference between the triplet and singlet excited states is 0 eV or more and 0.2 eV or less, preferably 0 eV or more and 0.1 eV or less. The delayed fluorescence emitted by TADF materials refers to luminescence with the same spectrum as ordinary fluorescence but with a very long lifetime. Its lifetime is 1 × 10⁻⁶ seconds or more, preferably 1 × 10⁻³ seconds or more.

[0280] Examples of TADF materials include fullerenes and their derivatives, acridine derivatives such as proflavin, and eosin. In addition, examples include metallic violets containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd). Examples of metallic violet compounds include, for example, protoviolet-tin fluoride complex (SnF2(Proto IX)), mesoviolet-tin fluoride complex (SnF2(Meso IX)), hematoviolet-tin fluoride complex (SnF2(Hemato IX)), tetramethyl copropisyl tin fluoride complex (SnF2(Copro III-4Me)), octaethylviolet-tin fluoride complex (SnF2(OEP)), protoviolet-tin fluoride complex (SnF2(Etio I)), and octaethylviolet-platinum chloride complex (PtCl2OEP).

[0281] [Chemical Formula 63]

[0282] In addition to the above, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazole-11-yl)-1,3,5-triazine (abbreviated as: PIC-TRZ), 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviated as: PCCzPTzn), 2-[ [4-(10H-phenanthroline-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4-(5-phenyl-5,10-dihydrophenanthroline-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-oxanthracene-9-one (abbreviation: ACRXTN) ), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl] ion (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthracene]-10'-one (abbreviation: ACRSA), 4-(9'-phenyl-3,3'-bi-9H-carbazole-9-yl)benzofuran[3,2-d]pyrimidine (abbreviation: 4PCCzBfpm), 4-[4-(9'-phenyl Heteroaromatic compounds, including π-electron-rich and π-electron-deficient heteroaromatic compounds, are classified as follows: [4PCCzPBfpm]-[3,3'-bi-9H-carbazole-9-yl)phenyl]benzofuran[3,2-d]pyrimidine (abbreviated as mPCCzPTzn-02), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviated as mPCCzPTzn-02).

[0283] Furthermore, in substances where π-electron-rich heteroaromatic compounds and π-electron-deficient heteroaromatic compounds are directly bonded, the π-electron-rich heteroaromatic compounds exhibit strong donor properties and the π-electron-deficient heteroaromatic compounds exhibit strong acceptor properties, resulting in a smaller energy difference between the singlet and triplet excited states, making them particularly preferable. Additionally, as a TADF material, a TADF material in thermal equilibrium between the singlet and triplet excited states (TADF100) can also be used. This type of TADF material has a short luminescence lifetime (excitation lifetime), which can suppress efficiency reduction in the high-brightness region of the light-emitting element.

[0284] [Chemical Formula 64]

[0285] In addition to the above, nanostructures of transition metal compounds with a perovskite structure can be cited as materials capable of converting triple excitation energy into luminescence. Metal halide perovskite nanostructures are particularly preferred. Nanoparticles and nanorods are preferred as such nanostructures.

[0286] In the light-emitting layers (113, 113a, 113b, 113c), as an organic compound (host material, etc.) that combines the above-mentioned light-emitting material (guest material), one or more substances whose band gap is larger than that of the light-emitting material (guest material) can be used.

[0287] <<Fluorescent Host Material>> When the luminescent material used in the luminescent layers (113, 113a, 113b, 113c) is a fluorescent material, the organic compound (host material) used in combination with the luminescent material is preferably an organic compound with a high energy level of its singlet excited state and a low energy level of its triplet excited state, or an organic compound with a high fluorescence quantum yield. Therefore, any organic compound that meets the above conditions can be used, such as the hole transport material (described above) or the electron transport material (described later) shown in this embodiment.

[0288] Although some of the content is repeated with the specific examples above, from the viewpoint of being a better combination with luminescent substances (fluorescent substances), fused polycyclic aromatic compounds such as anthracene derivatives, fused tetrabenzene derivatives, phenanthrene derivatives, pyrene derivatives, chrysene derivatives, and dibenzo[g,p]chrysene derivatives can be cited as organic compounds (main materials).

[0289] Specific examples of organic compounds (host materials) preferably used in combination with fluorescent substances include 9-phenyl-3-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole (abbreviated as PCzPA), 3,6-diphenyl-9-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole (abbreviated as DPCzPA), 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPN), 9,10-diphenylanthracene (abbreviated as DPAN), N,N-diphenyl-9-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole-3-amine (abbreviated as CzA1PA), 4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole-3-amine (abbreviated as CzA1PA), and 4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole-3-amine. Anthrayl)triphenylamine (DPhPA), YGAPA, PCAPA, N,9-diphenyl-N-{4-[4-(10-phenyl-9-anthrayl)phenyl]phenyl}-9H-carbazole-3-amine (PCAPBA), N-(9,10-diphenyl-2-anthrayl)-N,9-diphenyl-9H-carbazole-3-amine (2PCAPA), 6,12-dimethoxy-5,11-diphenylamine, N,N,N',N',N'',N'',N'',N''',N'''-octaphenyldibenzo[g,p]phenyl-2,7,10,15-tetraamine (DBC1), 9-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole (Cz) PA), 7-[4-(10-phenyl-9-anthrayl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthrayl)phenyl]-benzo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10-{4-(9-phenyl-9H-en-9-yl)biphenyl-4'-yl}anthracene (abbreviation: FLPPA), 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 9,10-bis(2-naphthyl)anthracene (abbreviation: DNA), 2-tert-butyl-9,10-bis(2-naphthyl)anthracene (abbreviation: t-BuDNA), 9-(1-naphthyl)-10-( 2-Naphthyl)anthracene (abbreviation: α,β-ADN), 2-(10-phenylanthracene-9-yl)dibenzofuran, 2-(10-phenyl-9-anthrayl)-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-anthrayl)phenyl]-2-ethyl-1H-benzimidazole (abbreviation: EtBImPBPhA), 9,9'-bianthracene (abbreviation: BANT), 9,9'-(stilbene-3,3'-diyl)diphenanthrene (DPNS), 9,9'-(stilbene-4,4'-diyl)diphenanthrene (DPNS2), 1,3,5-tris(1-pyrene)benzene (TPB3), 5,12-diphenyltetraphenyl, 5,12-bis(biphenyl-2-yl)tetraphenyl, etc.

[0290] <<Phosphorescent Host Material>> When the luminescent material used for the luminescent layers (113, 113a, 113b, 113c) is a phosphorescent material, the organic compound (host material) used in combination with the luminescent material should be an organic compound whose triple excitation energy (the energy difference between the ground state and the triple excited state) is greater than the triple excitation energy of the luminescent material. Note that when multiple organic compounds (e.g., a first host material and a second host material (or auxiliary material)) are used in combination with the luminescent material to form an excited-state complex, it is preferable to use these multiple organic compounds mixed with the phosphorescent material.

[0291] By employing such a structure, luminescence via ExTET (Exciplex-Triplet Energy Transfer), which utilizes energy transfer from excited-state complexes to luminescent materials, can be obtained efficiently. As a combination of multiple organic compounds, it is preferable to use a combination that readily forms excited-state complexes, and particularly preferably a combination of compounds that readily accept holes (hole-transporting materials) and compounds that readily accept electrons (electron-transporting materials).

[0292] Although some content repeats the specific examples above, from the viewpoint of a preferred combination with luminescent substances (phosphorescent substances), examples of organic compounds (main materials, auxiliary materials) 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), acediazole derivatives (organic compounds having an acediazole ring), triazole derivatives (organic compounds having a triazole ring), and benzo[…]. Imidazole derivatives (organic compounds with a benzimidazole ring), quinoline derivatives (organic compounds with a quinoline ring), dibenzoquinoline derivatives (organic compounds with a dibenzoquinoline ring), pyrimidine derivatives (organic compounds with a pyrimidine ring), triazine derivatives (organic compounds with a triazine ring), pyridine derivatives (organic compounds with a pyridine ring), bipyridine derivatives (organic compounds with a bipyridine ring), phenoline derivatives (organic compounds with a phenoline ring), furandiazine derivatives (organic compounds with a furandiazine ring), zinc or aluminum metal complexes, etc.

[0293] Note that among the above-mentioned organic compounds, specific examples of aromatic amines and carbazole derivatives that are organic compounds with high hole transport properties can be given as materials that are the same as the specific examples of hole transport materials mentioned above, and these materials are preferably used as host materials.

[0294] In addition, as specific examples of dibenzothiophene derivatives and dibenzofuran derivatives of organic compounds with high hole transport properties among the above-mentioned organic compounds, 4-{3-[3-(9-phenyl-9H-en-9-yl)phenyl]phenyl}dibenzofuran (abbreviated as: mmDBFFLBi-II), 4,4',4''-(benzyl-1,3,5-triyl)tris(dibenzofuran) (abbreviated as: DBF3P-II), DBT 3P-II, 2,8-diphenyl-4-[4-(9-phenyl-9H-en-9-yl)phenyl]dibenzothiophene (abbreviated as DBTFLP-III), 4-[4-(9-phenyl-9H-en-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as DBTFLP-IV), 4-[3-(triphenyl-2-yl)phenyl]dibenzothiophene (abbreviated as mDBTPTp-II), etc., are preferred as host materials.

[0295] In addition, preferred host materials include bis[2-(2-benzothiazolyl)phenol]zinc(II) (abbreviated as ZnPBO) and bis[2-(2-benzothiazolyl)phenol]zinc(II) (abbreviated as ZnBTZ), which are metal complexes with benzothiazolyl ligands and thiazolyl ligands.

[0296] Furthermore, among the aforementioned organic compounds, specific examples of acediazole derivatives, triazole derivatives, benzimidazole derivatives, quinoline derivatives, dibenzoquinoline derivatives, quinazoline derivatives, and phenazolin derivatives, which are organic compounds with high electron transport properties, include 2-(4-biphenyl)-5-(4-tertiary butylphenyl)-1,3,4-acediazole (abbreviated as PBD), 1,3-bis[5-(p-tertiary butylphenyl)-1,3,4-acediazole-2-yl]benzene (abbreviated as OXD-7), 9-[4-(5-phenyl-1,3,4-acediazole-2-yl)phenyl]-9H-carbazole (abbreviated as CO11), 3-(4-biphenyl)-4-phenyl-5-( 4-Tributylphenyl)-1,2,4-triazole (abbreviated as TAZ), 2,2',2''-(1,3,5-phenyltriyl)tris(1-phenyl-1H-benzimidazole) (abbreviated as TPBI), 2-[3-(dibenzothiophene-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviated as mDBTBIm-II), 4,4'-bis(5-methylbenzoxazo-2-yl)stilbene (abbreviated as BzOs) and other organic compounds containing heteroaromatic rings with polyazole rings, ruberin (abbreviated as Bphen), copper bath (abbreviated as BCP), 2,9-bis(naphthyl-2-yl)-4,7-diphenyl-1,10-phenoline (abbreviated as NBphen), 2,2- Organic compounds containing heteroaromatic rings with pyridine rings, such as (1,3-phenylene)bis[9-phenyl-1,10-phenanthroline] (abbreviated as mPPhen2P), 2-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoline (abbreviated as 2mDBTPDBq-II), 2-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoline (abbreviated as 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoline (abbreviated as 2mCzBPDBq), and 2-[4-(3,6-diphenyl-9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoline Quinoline (abbreviated as: 2CzPDBq-III), 7-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoline (abbreviated as: 7mDBTPDBq-II), 6-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoline (abbreviated as: 6mDBTPDBq-II), 2-{4-[9,10-bis(2-naphthyl)-2-anthrayl]phenyl}-1-phenyl-1H-benzimidazole (abbreviated as: ZADN), 2-[4'-(9-phenyl-9H-carbazol-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoline (abbreviated as: 2mpPCBPDBq), etc., are preferred as host materials.

[0297] Among the above-mentioned organic compounds, specific examples of pyridine derivatives, diazine derivatives (including pyrimidine derivatives, pyrazine derivatives, and triazine derivatives), triazine derivatives, and furan diazine derivatives that are organic compounds with high electron transport properties include 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviated as: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothiophene)phenyl]pyrimidine (abbreviated as: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazole-9-yl)phenyl]pyrimidine (abbreviated as: 4,6mCzP2Pm), and 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-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-carbazole-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tris[3-(3-pyridine)phenyl]benzene (abbreviation: TmPyPB), 9,9'-[pyrimidin-4,6-diylbis(biphenyl-3,3'-diyl)]bis(9H-carbazole) (abbreviation: 4,6mCzBP2Pm), 2-[3'-(9,9-dimethyl-9H-en-2-yl)] -1,1'-biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 8-(1,1'-biphenyl-4-yl)-4-[3-(dibenzothiophene-4-yl)phenyl]-[1]benzofurano[3,2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 9-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furano[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 9-[(3'-dibenzothiophene-4-yl)biphenyl-4-yl]naphtho[1',2':4,5]furano[2,3-b]pyrazine (abbreviation: 9pmDBtBPNf) pr), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indo[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-[3'-(biphenyl-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'-spirodi(9H-furan)-2-yl]-1,3,5-triazine (abbreviation: BP-SFTzn), 2,6-bis(4-naphth-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzothiophene]-2-phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-[1,1'-biphenyl]-3-yl-4-phenyl-6-(8-[1,1':4',1''-triphenyl]-4-yl-1-dibenzofuranyl)-1,3,5-triazine (abbreviation: mBP-TPDBfTzn) Organic compounds containing heteroaromatic rings with diazine rings, such as 6-(1,1'-biphenyl-3-yl)-4-[3,5-bis(9H-carbazole-9-yl)phenyl]-2-phenylpyrimidine (abbreviated as: 6mBP-4Cz2PPm) and 4-[3,5-bis(9H-carbazole-9-yl)phenyl]-2-phenyl-6-(1,1'-biphenyl-4-yl)pyrimidine (abbreviated as: 6BP-4Cz2PPm), are preferred as host materials.

[0298] Among the above-mentioned organic compounds, specific examples of metal complexes that are organic compounds with high electron transport properties include: tris(8-hydroxyquinoline)aluminum(III) (abbreviated as Alq), tris(4-methyl-8-hydroxyquinoline)aluminum(III) (abbreviated as Almq3), bis(10-hydroxybenzo[h]quinoline)beryllium(II) (abbreviated as BeBq2), bis(2-methyl-8-hydroxyquinoline)(4-phenylphenol)aluminum(III) (abbreviated as BAlq), and bis(8-hydroxyquinoline)zinc(II) (abbreviated as Znq); metal complexes having quinoline rings or benzoquinoline rings, etc., and these materials are preferably used as host materials.

[0299] In addition, as preferred host materials, poly(2,5-pyridinediyl) (abbreviated as PPy), poly[(9,9-dihexylenyl-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviated as PF-Py), poly[(9,9-dioctylenyl-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviated as PF-BPy) and other polymeric compounds can also be used.

[0300] Furthermore, bipolar organic compounds with high hole transport and high electron transport include 9-phenyl-9'-(4-phenyl-2-quinazolinyl)-3,3'-bi-9H-carbazole (abbreviated as: PCCzQz), 2-[4'-(9-phenyl-9H-carbazolinyl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoline (abbreviated as: 2mpPCBPDBq), and 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indendrone. [2,1-b]carbazole (abbreviated as mINc(II)PTzn), 11-(4-[1,1'-biphenyl]-4-yl-6-phenyl-1,3,5-triazin-2-yl)-11,12-dihydro-12-phenyl-indole[2,3-a]carbazole (abbreviated as BP-Icz(II)Tzn), 7-[4-(9-phenyl-9H-carbazole-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviated as PC-cgDBCzQz) and other organic compounds with diazine rings can also be used as host materials.

[0301] <Electron Transport Layer> The electron transport layer (114, 114a, 114b) is a layer that transports electrons injected from the second electrode 102 or the charge generation layer (106, 106a, 106b) through the electron injection layer (115, 115a, 115b) described later to the light-emitting layer (113, 113a, 113b, 113c). As the electron transport material for the electron transport layer (114, 114a, 114b), it is preferably a material having an electron mobility of 1×10⁻⁶ cm² / Vs or higher when the square root of the electric field strength [V / cm] is 600. Furthermore, any material other than the one described above can be used as long as its electron transportability is higher than its hole transportability. Moreover, even a single layer of the electron transport layer (114, 114a, 114b) is effective, but a stacked structure of two or more layers can also be used. Note that because the above-mentioned hybrid material is heat-resistant, photolithography can be performed on the electron transport layer using the hybrid material to suppress the negative impact of thermal processing on device characteristics.

[0302] <<Electron Transport Material>> As an electron transport material that can be used in electron transport layers (114, 114a, 114b), an organic compound with high electron transport properties can be used, for example, a heteroaromatic compound. Note that a heteroaromatic compound refers to a cyclic compound containing at least two different elements in its ring. Note that the ring structure includes three-membered rings, four-membered rings, five-membered rings, six-membered rings, etc., and is particularly preferably a five-membered or six-membered ring. The heteroaromatic compound containing elements other than carbon is preferably one or more of nitrogen, oxygen, and sulfur. It is particularly preferred to use a nitrogen-containing heteroaromatic compound (nitrogen-containing heteroaromatic compound), and it is even more preferred to use a nitrogen-containing heteroaromatic compound or a π-electron-deficient heteroaromatic compound containing the nitrogen-containing heteroaromatic compound, etc., as a material with high electron transport properties (electron transport material).

[0303] A heteroaromatic compound is an organic compound having at least one heteroaromatic ring.

[0304] Note that the heteroaromatic ring has any one of the following: a pyridine ring, a diazine ring, a triazine ring, a polyazole ring, a methazole ring, and a thiazole ring. Furthermore, heteroaromatic rings having a diazine ring include those having a pyrimidine ring, a pyrazine ring, or a diazine ring. Additionally, heteroaromatic rings having a polyazole ring include those having an imidazole ring, a triazole ring, or a diazole ring.

[0305] Heteroaromatic rings include fused heteroaromatic rings with fused ring structures. Note that examples of fused heteroaromatic rings include quinoline rings, benzoquinoline rings, quinoline rings, dibenzoquinoline rings, quinazoline rings, benzoquinazoline rings, dibenzoquinazoline rings, phenoline rings, furan diazine rings, benzimidazole rings, etc.

[0306] Note that, as a heteroaromatic compound, for example, among heteroaromatic compounds that contain one or more of nitrogen, oxygen and sulfur in addition to carbon, examples of heteroaromatic compounds having a five-membered ring structure include heteroaromatic compounds having an imidazole ring, heteroaromatic compounds having a triazole ring, heteroaromatic compounds having an acetazole ring, heteroaromatic compounds having an acediazole ring, heteroaromatic compounds having a thiazole ring, and heteroaromatic compounds having a benzimidazole ring.

[0307] For example, among heteroaromatic compounds that contain 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 with heteroaromatic rings such as pyridine rings, diazine rings (including pyrimidine rings, pyrazine rings, pyrazine rings, etc.), triazine rings, and polyazole rings. Note that examples of heteroaromatic compounds having a bipyridine structure and heteroaromatic compounds having a terpyridine structure are also included, and these are examples of heteroaromatic compounds with pyridine rings.

[0308] Furthermore, examples of heteroaromatic compounds having a fused ring structure in which a portion of the above-mentioned six-membered ring structure are heteroaromatic compounds having fused heteroaromatic rings such as quinoline ring, benzoquinoline ring, quinoline ring, dibenzoquinoline ring, phenoline ring, furan diazine ring (including structures in which the furan ring of the furan diazine ring is fused with an aromatic ring), and benzimidazole ring.

[0309] Specific examples of heteroaromatic compounds having the above-mentioned five-membered ring structure (polyazole ring (including imidazole ring, triazole ring, acediazole ring), acediazole ring, thiazole ring, benzimidazole ring, etc.) include 2-(4-biphenyl)-5-(4-triterpenoidylphenyl)-1,3,4-acediazole (abbreviated as: PBD), 1,3-bis[5-(p-triterpenoidylphenyl)-1,3,4-acediazole-2-yl]benzene (abbreviated as: OXD-7), 9-[4-(5-phenyl-1,3,4-acediazole-2-yl)phenyl]-9H-carbazole (abbreviated as: CO11), 3-(4-biphenyl)-4-phenyl 5-(4-tertiary butylphenyl)-1,2,4-triazole (abbreviated as TAZ), 3-(4-tertiary butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenyl)-1,2,4-triazole (abbreviated as p-EtTAZ), 2,2',2''-(1,3,5-benzyltriyl)tris(1-phenyl-1H-benzimidazole) (abbreviated as TPBI), 2-[3-(dibenzothiophene-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviated as mDBTBIm-II), 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviated as BzOs), etc.

[0310] Specific examples of heteroaromatic compounds having the above-mentioned six-membered ring structure (including heteroaromatic rings having pyridine rings, diazine rings, triazine rings, etc.) include 3,5-bis[3-(9H-carbazo-9-yl)phenyl]pyridine (abbreviated as: 35DCzPPy), 1,3,5-tris[3-(3-pyridyl)phenyl]benzene (abbreviated as: TmPyPB), and other heteroaromatic compounds containing heteroaromatic rings having pyridine rings; 2-{4-[3-(N-phenyl-9H-carbazo-3-yl)-9H-carbazo-9-yl]phenyl}-4,6-diphenyl 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (mPCCzPTzn-02), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indo[2,1-b]carbazole (mINc(II)PTzn), 2-[3'-(biphenyl-2-yl)-1,1'-biphenyl-3-yl] ... 2-[(1,1'-biphenyl)-4-yl]-4-phenyl-6-[9,9'-spirobi(9H-furan)-2-yl]-1,3,5-triazine (abbreviation: mTpBPTzn), 2-[(1,1'-biphenyl)-4-yl]-4-phenyl-6-[9,9'-spirobi(9H-furan)-2-yl]-1,3,5-triazine (abbreviation: BP-SFTzn), 2,6-bis(4-naphthyl-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzothiophene]-2 1-Phenylacetic-9H-carbazole (abbreviated as PCDBfTzn), 2-[1,1'-biphenyl]-3-yl-4-phenyl-6-(8-[1,1':4',1''-triphenyl]-4-yl-1-dibenzofuranyl)-1,3,5-triazine (abbreviated as mBP-TPDBfTzn), 2-{3-[3-(dibenzothiophene-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviated as mDBtBPTzn), mFBPTzn and other heteroaromatic compounds containing heteroaromatic rings with triazine rings;4,6-Bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-Bis[3-(4-dibenzothiophene)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-Bis[3-(9H-carbazole-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 4,6mCzBP2Pm, 6-(1,1'-biphenyl-3-yl)-4-[3,5-bis(9H-carbazole-9-yl)phenyl]pyrimidine 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(1,1'-biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(1,1'-biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-8-(naphthyl)-[1]benzofurano[3,2-d]pyrimidine (abbreviation: 8βN-4mDBtPBfpm), 8BP -4mDBtPBfpm, 9mDBtBPNfpr, 9pmDBtBPNfpr, 3,8-bis[3-(dibenzothiophene-4-yl)phenyl]benzofurano[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-bis[3-(dibenzothiophene-4-yl)phenyl]-[1]benzofurano[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3'-(dibenzothiophene) -4-yl)(1,1'-biphenyl-3-yl)]naphtho[1',2':4,5]furano[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2'-binaphthyl)-6-yl]-4-[3-(dibenzothiophene-4-yl)phenyl]-[1]benzofurano[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm), and other heteroaromatic compounds containing a diazine (pyrimidine) ring, etc. Note that aromatic compounds containing the above heteroaromatic rings include heteroaromatic compounds with fused heteroaromatic rings.

[0311] In addition, examples include 2,2'-(pyridin-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviated as: 2,6(P-Bqn)2Py), 2,2'-(2,2'-bipyridin-6,6'-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviated as: 6,6'(P-Bqn)2BPy), 2,2'-(pyridin-2,6-diyl)bis{4-[4-(2-naphthyl)phenyl]-6-phenylpyrimidine} (abbreviated as: 2,6(NP-PPm)2Py), and 6-(1,1'-biphenyl-3-yl)-4-[3,5-bis(9H-carbazole-9-yl)phenyl] Heteroaromatic compounds containing a diazine (pyrimidine) ring, such as 2-phenylpyrimidine (abbreviated as 6mBP-4Cz2PPm); heteroaromatic compounds containing a triazine ring, such as 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine (abbreviated as TmPPPyTz), 2,4,6-tris(2-pyridyl)-1,3,5-triazine (abbreviated as 2Py3Tz), and 2-[3-(2,6-dimethyl-3-pyridyl)-5-(9-phenanthyl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviated as mPn-mDMePyPTzn).

[0312] Specific examples of heteroaromatic compounds (heteroaromatic compounds with fused ring structures) having a portion of the above-mentioned six-membered ring structure include ruberin (abbreviated as Bphen), copper oxychloride (abbreviated as BCP), 2,9-bis(naphthyl-2-yl)-4,7-diphenyl-1,10-phenerin (abbreviated as NBphen), 2,2-(1,3-phenylene)bis[9-phenyl-1,10-phenerin] (abbreviated as mPPhen2P), 2,2'-(pyridin-2,6-diyl)bis(4-phenylbenzo[h]quinazolin) (abbreviated as 2,6(P-Bqn)2Py), 2-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinazolin (abbreviated as 2mDBTPDBq-II), 2-[3' ... [Benzothiophene-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoline (abbreviation: 2mCzBPDBq), 2-[4-(3,6-diphenyl-9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoline (abbreviation: 2mCzBPDBq) These are heteroaromatic compounds with quinoline rings, such as 2CzPDBq-III, 7-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoline (abbreviated as 7mDBTPDBq-II), 6-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoline (abbreviated as 6mDBTPDBq-II), and 2mpPCBPDBq.

[0313] In addition to the heteroaromatic compounds mentioned above, the electron transport layers (114, 114a, 114b) can also use the following metal complexes. Examples of such metal complexes include tris(8-hydroxyquinoline)aluminum(III) (abbreviated as Alq3), Almq3, lithium(I) (abbreviated as Liq), BeBq2, bis(2-methyl-8-hydroxyquinoline)(4-phenylphenol)aluminum(III) (abbreviated as BAlq), bis(8-hydroxyquinoline)zinc(II) (abbreviated as Znq) and other metal complexes having quinoline rings or benzoquinoline rings, bis[2-(2-benzo ...

[0314] In addition, as electron transport materials, polymers such as poly(2,5-pyridinediyl) (abbreviated as PPy), poly[(9,9-dihexylfuran-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviated as PF-Py), and poly[(9,9-dioctylfuran-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviated as PF-BPy) can also be used.

[0315] In addition, the electron transport layers (114, 114a, 114b) can be a single layer or a stack of two or more layers containing the above-mentioned substances.

[0316] <Electron Injection Layer> The electron injection layer (115, 115a, 115b) is a layer containing a material with high electron injection capability. Furthermore, the electron injection layer (115, 115a, 115b) is a layer used to improve the efficiency of electron injection from the second electrode 102, and preferably uses a material whose work function value for the material used in the second electrode 102 is small (less than 0.5 eV) compared to the LUMO energy level value of the material used in the electron injection layer (115, 115a, 115b). Therefore, lithium, cesium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), lithium 8-(hydroxyoxoline) (Liq), lithium 2-(2-pyridyl)phenol (LiPP), lithium 2-(2-pyridyl)-3-hydroxypyridinolato (LiPPy), lithium 4-phenyl-2-(2-pyridyl)phenol (LiPPP), lithium oxide (LiOx), cesium carbonate, and other alkali metals, alkaline earth metals, or compounds thereof can be used as the electron injection layer 115. Furthermore, rare earth metal compounds such as erbium fluoride (ErF3) and ytterbium (Yb) can also be used. Note that the electron injection layers (115, 115a, 115b) can be formed by mixing or stacking multiple of the above materials. Additionally, electron compounds can be used in the electron injection layers (115, 115a, 115b). Examples of electronic compounds include mixed oxides of calcium and aluminum that add electrons at high concentrations. Additionally, substances constituting the electron transport layers (114, 114a, 114b) as described above can also be used.

[0317] Alternatively, a mixed material consisting of a mixed organic compound and an electron donor (donor) can be used in the electron injection layer (115, 115a, 115b). This mixed material exhibits excellent electron injection and electron transport properties because electrons are generated in the organic compound through the electron donor. In this case, the organic compound is preferably a material with excellent performance in transporting the generated electrons. Specifically, for example, electron transport materials (metal complexes and heteroaromatic compounds, etc.) used in the electron transport layers (114, 114a, 114b) as described above can be used. As the electron donor, any substance exhibiting electron donor properties in the organic compound is acceptable. Specifically, alkali metals, alkaline earth metals, and rare earth metals are preferred, such as lithium, cesium, magnesium, calcium, erbium, and ytterbium. Furthermore, alkali metal oxides and alkaline earth metal oxides are preferred, such as lithium oxide, calcium oxide, and barium oxide. Additionally, Lewisite such as magnesium oxide can also be used. Alternatively, organic compounds such as tetrathiofulvalene (TTF) can be used. Multiple of these materials can also be stacked.

[0318] In addition, a hybrid material consisting of a mixture of organic compounds and metals can also be used for the electron injection layer (115, 115a, 115b). Note that the organic compounds used here are preferably those with a LUMO energy level of -3.6 eV or higher and -2.3 eV or lower. Furthermore, materials with non-shared electron pairs are preferred.

[0319] Therefore, as the organic compound used in the above-mentioned mixed material, a mixed material formed by mixing the above-mentioned heteroaromatic compounds that can be used in the electron transport layer with a metal can also be used. The heteroaromatic compounds are preferably heteroaromatic compounds having a five-membered ring structure (imidazolium ring, triazole ring, oxazole ring, oxadiazole ring, thiazole ring, benzimidazole ring, etc.), heteroaromatic compounds having a six-membered ring structure (pyridine ring, diazine ring (including pyrimidine ring, pyrazine ring, pyrazine ring, etc.), triazine ring, bipyridine ring, terpyridine ring, etc.), or heteroaromatic compounds having a partially fused ring structure with a six-membered ring structure (quinoline ring, benzoquinoline ring, quinoline ring, dibenzoquinoline ring, benziline ring, etc.), etc., and other materials having non-shared electron pairs. Specific materials have been described above, so their description is omitted here.

[0320] As the metal used in the above-mentioned mixed material, it is preferable to use a transition metal belonging to Group 5, Group 7, Group 9 or Group 11 of the periodic table, or a material belonging to Group 13, for example, Ag, Cu, Al or In. In addition, at this time, a single-occupied molecular orbital (SOMO) is formed between the organic compound and the transition metal.

[0321] Furthermore, for example, when amplifying the light received from the light-emitting layer 113b, it is preferable to form the light so that the optical distance between the second electrode 102 and the light-emitting layer 113b is less than 1 / 4 of the wavelength λ of the light emitted by the light-emitting layer 113b. In this case, the optical distance can be adjusted by changing the thickness of the electron transport layer 114b or the electron injection layer 115b.

[0322] Furthermore, as shown in FIG4D, by providing a charge generation layer 106 between two EL layers (103a, 103b), a structure in which multiple EL layers are stacked between a pair of electrodes can be formed (also known as a series structure).

[0323] <Charge Generation Layer> The charge generation layer 106 functions as follows: when a voltage is applied between the first electrode 101 (anode) and the second electrode 102 (cathode), electrons are injected into the EL layer 103a and holes are injected into the EL layer 103b. The charge generation layer 106 can have a structure that adds an electron acceptor (acceptor) to the hole transport material, or it can have a structure that adds an electron donor (donor) to the electron transport material. Alternatively, both of these structures can be stacked. Note that by using the above-described materials to form the charge generation layer 106, the rise in driving voltage caused by stacking the EL layers can be suppressed.

[0324] When the charge generation layer 106 has a structure that adds an electron acceptor to the hole transport material of the organic compound, the material shown in this embodiment can be used as the hole transport material. Furthermore, examples of electron acceptors include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinone dimethane (abbreviated as F4-TCNQ) and chloroquinone. Additionally, oxides of metals belonging to Groups 4 to 8 of the periodic table can be used. Specifically, examples include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide.

[0325] When the charge generation layer 106 has a structure that adds an electron donor to the electron transport material, the material shown in this embodiment can be used as the electron transport material. Furthermore, alkali metals, alkaline earth metals, rare earth metals, or metals belonging to Groups 2 and 13 of the periodic table, and their oxides or carbonates, can be used as electron donors. Specifically, lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium oxide, cesium carbonate, etc., are preferred. In addition, organic compounds such as tetrathianaphthacene can also be used as electron donors.

[0326] Although Figure 4D shows a structure with two stacked EL layers 103, it can be made into a stacked structure with more than three layers by setting a charge generation layer between different EL layers.

[0327] <Substrate> The light-emitting device shown in this embodiment can be formed on various substrates. Note that there is no specific limitation on the type of substrate. Examples of such substrates include semiconductor substrates (e.g., single-crystal substrates or silicon substrates), SOI substrates, glass substrates, quartz substrates, plastic substrates, metal substrates, stainless steel substrates, substrates containing stainless steel foil, tungsten substrates, substrates containing tungsten foil, flexible substrates, laminated films, and paper or substrate films containing fibrous materials.

[0328] Examples of glass substrates include barium borosilicate glass, aluminum borosilicate glass, and soda-lime glass. Examples of flexible substrates, laminating films, and substrate films include plastics such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyether ether (PES), synthetic resins such as acrylic resins, polypropylene, polyester, polyvinyl fluoride, polyvinyl chloride, polyamide, polyimide, aromatic polyamide, epoxy resin, inorganic vapor-deposited films, and paper.

[0329] Furthermore, when manufacturing the light-emitting device shown in this embodiment, vapor phase methods such as vapor deposition or liquid phase methods such as spin coating or inkjet printing can be used. When using vapor deposition, physical vapor deposition (PVD) methods such as sputtering, ion plating, ion beam vapor deposition, molecular beam vapor deposition, and vacuum vapor deposition or chemical vapor deposition (CVD) methods can be used. In particular, layers with various functions (hole injection layer 111, hole transport layer 112, light-emitting layer 113, electron transport layer 114, electron injection layer 115) included in the EL layer of the light-emitting device can be formed using methods such as vapor deposition (vacuum vapor deposition), coating methods (dip coating, dye coating, rod coating, spin coating, spray coating, etc.), and printing methods (inkjet printing, screen printing, lithography, flexographic printing, photogravure printing, micro-contact printing, etc.).

[0330] Note that when using the film-forming methods described above, such as coating and printing, high molecular weight compounds (oligomers, dendritic polymers, polymers, etc.), medium molecular weight compounds (compounds between low and high molecular weight: molecular weight 400 or higher and 4000 or lower), and inorganic compounds (quantum dot materials, etc.) can be used. Note that as quantum dot materials, colloidal quantum dot materials, alloy-type quantum dot materials, core-shell quantum dot materials, and core-type quantum dot materials can be used.

[0331] The materials of each layer (hole injection layer 111, hole transport layer 112, light emission layer 113, electron transport layer 114, electron injection layer 115) constituting the EL layer 103 of the light-emitting device shown in this embodiment are not limited to the materials shown in this embodiment. Any materials that can satisfy the function of each layer can be used in combination.

[0332] Note that in this specification, the terms "layer" and "film" may be interchanged.

[0333] The structure shown in this embodiment can be used in appropriate combination with the structures shown in other embodiments.

[0334] Embodiment 3 In this embodiment, a specific structural example and manufacturing method of a light-receiving device as an embodiment of the present invention will be described.

[0335] <Structural Example of Light Receiving Device 700> The light receiving device 700 shown in FIG5A includes light-emitting device 550B, light-emitting device 550G, light-emitting device 550R, and light-receiving device 550PS. Furthermore, the light-emitting device 550B, light-emitting device 550G, light-emitting device 550R, and light-receiving device 550PS are formed on a functional layer 520 disposed on a first substrate 510. The functional layer 520 includes not only driving circuits such as GD and SD composed of multiple transistors, but also wiring that electrically connects them. As an example, these driving circuits are electrically connected to the light-emitting device 550B, light-emitting device 550G, light-emitting device 550R, and light-receiving device 550PS respectively, and can drive these devices. Furthermore, the light receiving device 700 includes an insulating layer 705 on the functional layer 520 and each device (light-emitting device and light-receiving device), which has the function of bonding the second substrate 770 and the functional layer 520.

[0336] Note that the light-emitting device 550B, light-emitting device 550G, light-emitting device 550R, and light-receiving device 550PS have the device structures shown in Embodiments 1 and 2. That is, each light-emitting device has any structure shown in Figures 4A to 4E, and the light-receiving device has the structure shown in Figure 1C. Furthermore, in the light-receiving device shown in Figure 3A, a portion of the EL layer of the light-emitting device (hole injection layer, hole transport layer, and electron transport layer) and a portion of the light-receiving layer of the light-receiving device (first carrier transport layer and second carrier transport layer) are formed simultaneously using the same material in the manufacturing process. However, in this embodiment, it is described that each device (multiple light-emitting devices and light-receiving devices) except for the light-emitting device and the light-receiving device can be formed separately.

[0337] In this specification, the structure in which light-emitting layers of light-emitting devices (e.g., blue (B), green (G), and red (R)) and light-receiving layers of light-receiving devices are formed or coated with different colors is sometimes referred to as an SBS (Side By Side) structure. Furthermore, although light-emitting devices 550B, 550G, 550R, and 550PS are arranged sequentially in the light-receiving device 700 shown in FIG. 5A, one embodiment of the present invention is not limited to this structure. For example, in the light-receiving device 700, the above-mentioned devices may also be arranged in the order of light-emitting device 550R, light-emitting device 550G, light-emitting device 550B, and light-receiving device 550PS.

[0338] In FIG. 5A, the light-emitting device 550B includes electrodes 551B and 552, and an EL layer 103B. Furthermore, the light-emitting device 550G includes electrodes 551G, 552, and an EL layer 103G. Furthermore, the light-emitting device 550R includes electrodes 551R, 552, and an EL layer 103R. Furthermore, the light-receiving device 550PS includes electrodes 551PS, 552, and a light-receiving layer 103PS. The specific structure of each layer of the light-receiving device is as shown in Embodiment 1. Furthermore, the specific structure of each layer of the light-emitting device is as shown in Embodiment 2. Furthermore, the EL layers 103B, 103G, and 103R have a stacked structure composed of multiple layers with different functions, including light-emitting layers (105B, 105G, 105R). Furthermore, the light-receiving layer 103PS has a stacked structure composed of multiple layers with different functions, including an active layer 105PS. Figure 5A illustrates the following cases: EL layer 103B includes a hole injection / transport layer 104B, a light-emitting layer 105B, an electron transport layer 108B, and an electron injection layer 109; EL layer 103G includes a hole injection / transport layer 104G, a light-emitting layer 105G, an electron transport layer 108G, and an electron injection layer 109; EL layer 103R includes a hole injection / transport layer 104R, a light-emitting layer 105R, an electron transport layer 108R, and an electron injection layer 109; and light-receiving layer 103PS includes a first transport layer 104PS, an active layer 105PS, a buffer layer 220, a second transport layer 108PS, and an electron injection layer 109. However, the present invention is not limited thereto. Furthermore, the hole injection / transport layers (104B, 104G, 104R) show layers having the functions of the hole injection layer and hole transport layer shown in Embodiment 2, and may also have a stacked structure.

[0339] Furthermore, the electron transport layers (108B, 108G, 108R) and the second transport layer 108PS may also have the function of suppressing holes from the anode side to the cathode side via the EL layers (103B, 103G, 103R) and the light-receiving layer 103PS. In addition, the electron injection layer 109 may also have a stacked structure in which some or all of its components are made of different materials.

[0340] Furthermore, as shown in FIG5A, insulating layers (107B, 107G, 107R, 107PS) are formed on the sides (or ends) of the hole injection / transport layers (104B, 104G, 104R), light-emitting layers (105B, 105G, 105R), and electron transport layers (108B, 108G, 108R) in the EL layers (103B, 103G, 103R), and on the sides (or ends) of the first transport layer 104PS, active layer 105PS, and second transport layer 108PS in the light-receiving layer 103PS. The insulating layers (107B, 107G, 107R, 107PS) are in contact with the sides (or ends) 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 interior from the sides of the EL layer (103B, 103G, 103R) and the light-receiving layer 103PS. Furthermore, the insulating layers (107B, 107G, 107R, 107PS) can be, for example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, or silicon oxynitride. Additionally, the insulating layers (107B, 107G, 107R, 107PS) can also be formed by laminating the aforementioned materials. Furthermore, the insulating layers (107B, 107G, 107R, 107PS) can be formed using sputtering, CVD, MBE, PLD, ALD, etc., with ALD, which offers good coverage, being preferred. Furthermore, insulating layers (107B, 107G, 107R, 107PS) continuously cover a portion of the EL layer (103B, 103G, 103R) of adjacent light-emitting devices or a portion of the light-receiving layer 103PS of a light-receiving device. For example, in FIG5A, a portion of the EL layer 103B of light-emitting device 550B and a portion of the EL layer 103G of light-emitting device 550G are covered by insulating layers (107G, 107R). Furthermore, it is preferable to form a partition wall 528 made of insulating material, as shown in FIG5A, in the area covered by the insulating layers (107G, 107R).

[0341] Furthermore, an electron injection layer 109 is formed on the electron transport layer (108B, 108G, 108R) which is part of the EL layer (103B, 103G, 103R), the second transport layer 108PS which is part of the light-receiving layer 103PS, and the insulating layer (107B, 107G, 107R, 107PS). In addition, the electron injection layer 109 may also have a stacked structure of two or more layers (e.g., layers with different stacking resistances).

[0342] Furthermore, electrode 552 is formed on electron injection layer 109. Additionally, electrodes (551B, 551G, 551R) and electrode 552 have overlapping regions. Furthermore, a light-emitting layer 105B is present between electrode 551B and electrode 552, a light-emitting layer 105G is present between electrode 551G and electrode 552, a light-emitting layer 105R is present between electrode 551R and electrode 552, and a light-receiving layer 103PS is present between electrode 551PS and electrode 552.

[0343] Furthermore, the EL layers (103B, 103G, 103R) shown in FIG5A have the same structure as the EL layer 103 described in Embodiment 2. Furthermore, the light-receiving layer 103PS has the same structure as the light-receiving layer 203 described in Embodiment 1. Furthermore, 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.

[0344] A partition wall 528 is provided in the area surrounded by the electron injection layer 109 and the insulating layers (107B, 107G, 107R, 107PS). As shown in FIG5A, a portion of the electrodes (551B, 551G, 551R, 551PS), the EL layer (103B, 103G, 103R), and a portion of the light-receiving layer 103PS of each light-emitting device are in contact with the side (or end) of the partition wall 528 through the insulating layers (107B, 107G, 107R, 107PS).

[0345] In each EL layer and light-receiving layer, especially in the hole transport region located between the anode and the light-emitting layer and between the anode and the active layer, the hole injection layer often has high conductivity. Therefore, if it is formed as a layer shared by adjacent devices, this can sometimes lead to crosstalk. Thus, as in this structural example, by providing a partition wall 528 made of insulating material between each EL layer and the light-receiving layer, crosstalk between adjacent devices can be suppressed.

[0346] In the manufacturing method shown in this embodiment, the sides (or ends) of the EL layer and the light-receiving layer are exposed during the patterning process. Therefore, oxygen, moisture, or their constituent elements can enter from the sides (or ends) of the EL layer and the light-receiving layer, making it easy for the EL layer and the light-receiving layer to deteriorate. Therefore, by providing the partition wall 528, the deterioration of the EL layer and the light-receiving layer during the manufacturing process can be suppressed.

[0347] By providing the partition wall 528, the recesses formed between adjacent devices can be planarized. Furthermore, by planarizing the recesses, the disconnection of the electrodes 552 formed on each EL layer and the light-receiving layer can be suppressed. Additionally, as the insulating material used to form the partition wall 528, organic materials such as acrylic resin, polyimide resin, epoxy resin, imide resin, polyimide resin, polyimide-polyamide resin, silicone resin, silicone resin, benzocyclobutene resin, phenolic resin, and precursors of these resins can be used. Furthermore, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerol, pullulan, water-soluble cellulose, or polyimide resins soluble in alcohols can also be used. Furthermore, photosensitive resins such as photoresists can be used. Note that the photosensitive resin can be a positive or negative material.

[0348] By using a photosensitive resin, the separator 528 can be manufactured using only an exposure and development process. Alternatively, a negative photosensitive resin (such as a photoresist material) can be used to form the separator 528. Furthermore, when using an insulating layer containing organic materials as the separator 528, it is preferable to use a material that absorbs visible light. By using a material that absorbs visible light in the separator 528, light emitted from the EL layer can be absorbed by the separator 528, thereby suppressing light (stray light) that may leak into adjacent EL layers and light-receiving layers. Therefore, a display panel with high display quality can be provided.

[0349] Furthermore, the difference between the height of the top surface of the partition wall 528 and the height of the top surface of any one of the EL layers 103B, EL layers 103G, EL layers 103R, and light-receiving layer 103PS is preferably 0.5 times or less, and more preferably 0.3 times or less, the thickness of the partition wall 528. Alternatively, for example, the partition wall 528 may be provided such that the top surface of any one of the EL layers 103B, EL layers 103G, EL layers 103R, and light-receiving layer 103PS is higher than the top surface of the partition wall 528. Alternatively, for example, the partition wall 528 may be provided such that the top surface of the partition wall 528 is higher than the top surfaces of the EL layers 103B, EL layers 103G, EL layers 103R, and light-receiving layer 103PS.

[0350] In a high-definition light-emitting device (display panel) with a resolution exceeding 1000 ppi, crosstalk occurs when electrical conduction occurs between the EL layer 103B, EL layer 103G, EL layer 103R, and light-receiving layer 103PS, thus narrowing the color gamut that the light-emitting device can display. By providing partition walls 528 in a high-definition display panel with a resolution exceeding 1000 ppi, preferably a high-definition display panel with a resolution exceeding 2000 ppi, and more preferably an ultra-high-definition display panel with a resolution exceeding 5000 ppi, a display panel capable of displaying vibrant colors can be provided.

[0351] Figures 5B and 5C are top views of the light-emitting device 700 along the dashed lines Ya-Yb in the cross-sectional view corresponding to that in Figure 5A. That is, light-emitting devices 550B, 550G, and 550R are arranged in a matrix. Note that Figure 5B shows a so-called strip arrangement of light-emitting devices of the same color in the Y direction. Furthermore, Figure 5C shows a structure in which light-emitting devices of the same color are arranged in the Y direction, forming a pattern per pixel. Note that the arrangement of the light-emitting devices is not limited to this; arrangements such as Delta arrangement, zigzag arrangement, Pentile arrangement, and Diamond arrangement can be used.

[0352] Note that since patterning is performed using photolithography in the separation processing of each EL layer (EL layer 103B, EL layer 103G, and EL layer 103R) and the light-receiving layer 103PS, a high-definition light-receiving device (display panel) can be manufactured. Furthermore, the ends (sides) of the EL layers processed using photolithography have a shape including approximately the same surface (or, located on approximately the same plane). Similarly, the sides (ends) of each layer of the light-receiving layer processed using photolithography have a shape including approximately the same surface (or, located on approximately the same plane). In this case, the width (SE) of the gap 580 provided between each EL layer and the light-receiving layer is preferably 5 μm or less, more preferably 1 μm or less.

[0353] In the EL layer, especially the hole injection layer located in the hole transport region between the anode and the light-emitting layer, the conductivity is often high. Therefore, if it is formed as a layer shared by adjacent light-emitting devices, this can sometimes lead to crosstalk. Therefore, as in this example structure, crosstalk between adjacent light-emitting devices can be suppressed by performing patterning using photolithography to separate the EL layer.

[0354] FIG5D is a cross-sectional schematic diagram corresponding to the dashed line C1-C2 in FIG5B and FIG5C. FIG5D shows the connection portion 130 for electrically connecting electrode 551C and electrode 552. In the connection portion 130, electrode 552 is provided on the connecting electrode 551C in a manner that contacts it. In addition, a partition wall 528 is provided to cover the end of the connecting electrode 551C.

[0355] <Example of manufacturing method of light-emitting device> As shown in FIG6A, electrodes 551B, 551G, 551R and 551PS are formed. For example, a conductive film is formed on the functional layer 520 formed on the first substrate 510, and the conductive film is processed into a specified shape by photolithography.

[0356] Note that conductive films can be formed using methods such as sputtering, chemical vapor deposition (CVD), molecular beam epitaxy (MBE), vacuum evaporation, pulsed laser deposition (PLD), and atomic layer deposition (ALD). Examples of CVD methods include plasma-enhanced chemical vapor deposition (PECVD) and thermal CVD. Furthermore, metal-organic chemical vapor deposition (MOCVD) is one example of a thermal CVD method.

[0357] In addition, when processing conductive films, besides the photolithography method mentioned above, nanoimprinting, sandblasting, and peeling methods can also be used to process the films. Furthermore, island-shaped films can also be formed directly using shadow masking methods such as metal masks.

[0358] There are typically two methods for photolithography. One method involves forming a photoresist mask on the film to be processed, processing the film by etching or the like, and then removing the photoresist mask. The other method involves forming a photosensitive film, then exposing and developing it to process the film into the desired shape. Note that when using the former method, there are heat treatment processes such as pre-applied bake (PAB) and post-exposure bake (PEB). In one embodiment of the present invention, photolithography is used not only in the processing of conductive films but also in the processing of films used to form EL layers (films formed of organic compounds or films in which a portion of the film contains organic compounds).

[0359] In photolithography, the light used for exposure can be, for example, i-rays (wavelength 365 nm), g-rays (wavelength 436 nm), h-rays (wavelength 405 nm), or a mixture of these rays. Additionally, ultraviolet light, KrF lasers, or ArF lasers can also be used. Furthermore, immersion exposure techniques can be employed. Additionally, extreme ultraviolet (EUV) light or X-rays can be used as the light for exposure. Furthermore, an electron beam can be used instead of the light used for exposure. When using extreme ultraviolet light, X-rays, or an electron beam, extremely fine processing can be performed, making it preferable. Note that when exposure is performed by scanning with a beam such as an electron beam, a photomask is not required.

[0360] As a thin film etching using a photoresist mask, dry etching, wet etching, sandblasting, etc. can be used.

[0361] Next, as shown in FIG6B, a hole injection / transport layer 104B, a light-emitting layer 105B, and an electron transport layer 108B are formed on electrodes 551B, 551G, 551R, and 551PS. For example, the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B can be formed using a vacuum evaporation method. Furthermore, a sacrificial layer 110B is formed on the electron transport layer 108B. When forming the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B, the materials shown in Embodiment 2 can be used.

[0362] The sacrificial layer 110B is preferably a film with high resistance to etching of the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B, that is, a film with a relatively large etching selectivity. Furthermore, the sacrificial layer 110B is preferably a stacked structure of a first sacrificial layer and a second sacrificial layer with different etching selectivities. Additionally, the sacrificial layer 110B can be a film that can be removed by a wet etching method that causes minimal damage to the EL layer 103B. Oxalic acid or the like can be used as the etching material for wet etching.

[0363] As the sacrificial layer 110B, an inorganic film such as a metal film, alloy film, metal oxide film, semiconductor film, or inorganic insulating film can be used. In addition, the sacrificial layer 110B can be formed by various film formation methods such as sputtering, vapor deposition, CVD, and ALD.

[0364] As the sacrificial layer 110B, for example, metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloy materials containing such metallic materials, can be used. In particular, low-melting-point materials such as aluminum or silver are preferred.

[0365] Furthermore, indium gallium zinc oxide (In-Ga-Zn oxide, also known as IGZO) or other metal oxides can be used as the sacrificial layer 110B. Other suitable oxides 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 or similar materials can be used.

[0366] Note that element M (selected from one or more of aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) may be used instead of gallium. In particular, M is preferably selected from one or more of gallium, aluminum, and yttrium.

[0367] In addition, inorganic insulating materials such as alumina, hafnium oxide, and silicon oxide can be used as the sacrificial layer 110B.

[0368] As the sacrificial layer 110B, it is preferable to use a material that is soluble in a solvent, that is, a solvent that exhibits chemical stability at least to the uppermost electron transport layer 108B. In particular, a material soluble in water or alcohol can be appropriately used as the sacrificial layer 110B. When depositing the sacrificial layer 110B, it is preferable to apply the material by a wet deposition method in a state dissolved in a solvent such as water or alcohol, and then perform a heat treatment to evaporate the solvent. At this time, by performing heat treatment under a reduced pressure atmosphere, the solvent can be removed at a low temperature and in a short time, so thermal damage to the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B can be reduced, which is therefore preferable.

[0369] Note that when forming the sacrificial layer 110B with a stacked structure, the layer formed by the above-mentioned material can be used as the first sacrificial layer, and a second sacrificial layer can be formed on it to form a stacked structure.

[0370] At this time, 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 during the processing of the second sacrificial layer. Therefore, a combination of films with a relatively large etching selectivity is selected as the first and second sacrificial layers. Thus, a film suitable for the second sacrificial layer can be selected based on the etching conditions of the first and second sacrificial layers.

[0371] For example, when dry etching using a fluorine-containing gas (also known as a fluorine-based gas) is used as the second sacrificial layer, silicon, silicon nitride, silicon oxide, tungsten, titanium, molybdenum, tantalum, tantalum nitride, alloys containing molybdenum and niobium, or alloys containing molybdenum and tungsten can be used as the second sacrificial layer. Here, as films with a relatively large etching selectivity (i.e., a slower etching rate) for the aforementioned dry etching using fluorine-based gases, metal oxide films such as IGZO and ITO can be used as the first sacrificial layer.

[0372] Furthermore, not limited thereto, the second sacrificial layer may be selected from various materials depending on the etching conditions of the first sacrificial layer and the etching conditions of the second sacrificial layer. For example, it may also be selected from films that can be used for the first sacrificial layer described above.

[0373] Furthermore, a nitride film can be used as the second sacrificial layer, for example. Specifically, silicon nitride, aluminum nitride, hafnium nitride, titanium nitride, tantalum nitride, tungsten nitride, gallium nitride, germanium nitride, and other nitrides can be used.

[0374] In addition, an oxide film can be used as the second sacrificial layer. Typically, oxide films or oxynitride films such as silicon oxide, silicon oxynitride, aluminum oxide, aluminum oxynitride, hafnium oxide, and hafnium oxynitride can be used.

[0375] Next, as shown in FIG6C, a photoresist is coated on the sacrificial layer 110B, and the photoresist is shaped into the desired shape (photoresist mask: REG) using photolithography. Furthermore, this method involves heat treatment processes such as pre-applied bake (PAB) and post-exposure bake (PEB). For example, the PAB temperature is approximately 100°C, and the PEB temperature is approximately 120°C. Therefore, the light-emitting device needs to be able to withstand these processing temperatures.

[0376] Next, a portion of the sacrificial layer 110B not covered by the photoresist mask REG is removed by etching using the obtained photoresist mask REG, and the photoresist mask REG is removed. Then, the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B not covered by the sacrificial layer 110B are removed by etching. The hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B are processed into a shape having sides (or exposed sides) on the electrode 551B or a strip shape extending in a direction intersecting the page. As an etching method, dry etching is preferred. When the sacrificial layer 110B has the aforementioned stacked structure of the first sacrificial layer and the second sacrificial layer, the photoresist mask REG can be removed after etching a portion of the second sacrificial layer using the photoresist mask REG, and the second sacrificial layer can be used as a mask to etch a portion of the first sacrificial layer to process the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B into a predetermined shape. By performing these etching processes, the shape of FIG7A is obtained.

[0377] Next, as shown in FIG7B, a hole injection / transport layer 104G, a light-emitting layer 105G, and an electron transport layer 108G are formed on the sacrificial layer 110B, electrode 551G, electrode 551R, and electrode 551PS. When forming the hole injection / transport layer 104G, the light-emitting layer 105G, and the electron transport layer 108G, the materials shown in Embodiment 2 can be used. Alternatively, for example, the hole injection / transport layer 104G, the light-emitting layer 105G, and the electron transport layer 108G can be formed using a vacuum evaporation method.

[0378] Next, as shown in FIG7C, a sacrificial layer 110G is formed on the electron transport layer 108G, and then a photoresist is coated on the sacrificial layer 110G. The photoresist is then formed into a desired shape (photoresist mask: REG) using photolithography. Next, a portion of the sacrificial layer 110G not covered by the obtained photoresist mask REG is removed by etching, and the photoresist mask REG is removed. Then, a portion of the hole injection / transport layer 104G, the light-emitting layer 105G, and the electron transport layer 108G not covered by the sacrificial layer 110G is removed by etching. The hole injection / transport layer 104G, the light-emitting layer 105G, and the electron transport layer 108G are processed into a shape having a side (or exposed side) on the electrode 551G or a strip shape extending in a direction intersecting the page. As an etching method, dry etching is preferred. As the sacrificial layer 110G, the same material as the sacrificial layer 110B can be used. When the sacrificial layer 110G has the aforementioned stacked structure of the first and second sacrificial layers, it is also possible to etch a portion of the second sacrificial layer using a photoresist mask REG, remove the photoresist mask REG, and then use the second sacrificial layer as a mask to etch a portion of the first sacrificial layer, thereby processing the hole injection / transport layer 104G, the light-emitting layer 105G, and the electron transport layer 108G into a predetermined shape. By performing these etching processes, the shape shown in FIG8A is obtained.

[0379] Next, as shown in FIG8B, 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. When forming the hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R, the materials shown in Embodiment 2 can be used. Alternatively, for example, the hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R can be formed using a vacuum evaporation method.

[0380] Next, as shown in FIG8C, a sacrificial layer 110R is formed on the electron transport layer 108R, and then a photoresist is coated on the sacrificial layer 110R. The photoresist is then formed into a desired shape (photoresist mask: REG) using photolithography. Next, a portion of the sacrificial layer 110R not covered by the obtained photoresist mask REG is removed by etching, and the photoresist mask REG is removed. Then, a portion of the hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R not covered by the sacrificial layer 110R is removed by etching. The hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R are processed into a shape having a side (or exposed side) on the electrode 551R or a strip shape extending in a direction intersecting the page. As an etching method, dry etching is preferred. As the sacrificial layer 110R, the same material as the sacrificial layer 110B can be used. When the sacrificial layer 110R has the aforementioned stacked structure of the first and second sacrificial layers, it is also possible to etch a portion of the second sacrificial layer using a photoresist mask REG, remove the photoresist mask REG, and then use the second sacrificial layer as a mask to etch a portion of the first sacrificial layer, thereby processing the hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R into a predetermined shape. By performing these etching processes, the shape shown in FIG. 9A is obtained.

[0381] Next, as shown in FIG9B, a first transport layer 104PS, an active layer 105PS, a buffer layer 220, and a second transport layer 108PS are formed on the sacrificial layers 110B, 110G, 110R, and electrode 551PS. When forming the first transport layer 104PS, the active layer 105PS, the buffer layer 220, and the second transport layer 108PS, the materials shown in Embodiments 1 and 2 can be used. For example, the first transport layer 104PS, the active layer 105PS, the buffer layer 220, and the second transport layer 108PS can be formed using a vacuum evaporation method.

[0382] Next, as shown in FIG9C, a sacrificial layer 110PS is formed on the second transport layer 108PS, and then a photoresist is coated on the sacrificial layer 110PS. The photoresist is then formed into a desired shape (photoresist mask: REG) using photolithography. Next, a portion of the sacrificial layer 110PS not covered by the obtained photoresist mask REG is removed by etching, and the photoresist mask REG is removed. Then, a portion of the first transport layer 104PS, the active layer 105PS, and the second transport layer 108PS not covered by the sacrificial layer 110PS is removed by etching, and the first transport layer 104PS, the active layer 105PS, and the second transport layer 108PS are processed into a shape having a side (or exposed side) on the electrode 551PS or a strip shape extending in a direction intersecting the page. As an etching method, dry etching is preferred. As the sacrificial layer 110PS, the same material as the sacrificial layer 110B can be used. When the sacrificial layer 110PS has the aforementioned stacked structure of the first and second sacrificial layers, it is also possible to etch a portion of the second sacrificial layer using a photoresist mask REG, remove the photoresist mask REG, and then use the second sacrificial layer as a mask to etch a portion of the first sacrificial layer, thereby processing the first transport layer 104PS, the active layer 105PS, and the second transport layer 108PS into a predetermined shape. By performing these etching processes, the shape shown in FIG9D is obtained.

[0383] Next, as shown in FIG10A, an insulating layer 107 is formed on the sacrificial layer 110B, sacrificial layer 110G, sacrificial layer 110R and sacrificial layer 110PS.

[0384] Furthermore, the insulating layer 107 can be formed, for example, using the ALD method. In this case, as shown in FIG10A, the insulating layer 107 is in contact with each side (each end) of the hole injection / transport layer (104B, 104G, 104R), the light-emitting layer (105B, 105G, 105R), the electron transport layer (108B, 108G, 108R), the first transport layer 104PS, the active layer 105PS, the buffer layer 220, and the second transport layer 108PS of each light-emitting device. This suppresses the entry of oxygen, moisture, or their constituent elements into the interior from each side. For example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, or silicon oxynitride can be used as the material for the insulating layer 107.

[0385] Next, as shown in FIG10B, after removing the sacrificial layers (110B, 110G, 110R, 110PS), a portion of the insulating layer 107 is removed, and then an electron injection layer 109 is formed on the formed insulating layers (107B, 107G, 107R, 107PS), electron transport layers (108B, 108G, 108R), and the second transport layer 108PS. When forming the electron injection layer 109, the material shown in Embodiment 2 can be used. For example, the electron injection layer 109 is formed using a vacuum evaporation method. Furthermore, the electron injection layer 109 is in contact with each side (end) of the hole injection / transport layer (104B, 104G, 104R), light-emitting layer (105B, 105G, 105R), electron transport layer (108B, 108G, 108R), first transport layer 104PS, active layer 105PS, buffer layer 220, and second transport layer 108PS of each light-emitting device, separated by an insulating layer (107B, 107G, 107R, 107PS).

[0386] Next, as shown in FIG10C, electrode 552 is formed. For example, electrode 552 is formed using vacuum evaporation. In addition, electrode 552 is formed on electron injection layer 109. Furthermore, electrode 552 is in contact with each side (each end) of hole injection / transport layer (104B, 104G, 104R), light-emitting layer (105B, 105G, 105R), and electron transport layer (108B, 108G, 108R) of each light-emitting device, first transport layer 104PS, active layer 105PS, buffer layer 220, and second transport layer 108PS of light-receiving device, through electron injection layer 109 and insulating layer (107B, 107G, 107R, 107PS). This prevents short circuits between the hole injection / transport layers (104B, 104G, 104R), light-emitting layers (105B, 105G, 105R), electron transport layers (108B, 108G, 108R), the first transport layer 104PS, the active layer 105PS, the buffer layer 220, and the second transport layer 108PS of each light-emitting device and the electrode 552.

[0387] Through the above process, the EL layers 103B, EL layers 103G, EL layers 103R and light-receiving layers 103PS in the light-emitting device 550B, light-emitting device 550G, light-emitting device 550R and light-receiving device 550PS can be separated and processed.

[0388] Note that since photolithography is used to form patterns in the separation process of these EL layers (EL layer 103B, EL layer 103G, EL layer 103R) and the light-receiving layer 103PS, a high-definition light-receiving device (display panel) can be manufactured. Furthermore, the ends (sides) of each EL layer processed by photolithography have a shape including a substantially identical surface (or, located on a substantially identical plane). Similarly, the sides (ends) of each light-receiving layer processed by photolithography have a shape including a substantially identical surface (or, located on a substantially identical plane).

[0389] 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 conductivity, which can sometimes lead to crosstalk if they are formed as layers shared between adjacent devices. Therefore, as in this example structure, crosstalk between adjacent devices can be suppressed by performing patterning using photolithography to separate the EL layers.

[0390] Furthermore, because a pattern is formed using photolithography during the separation and processing of the hole injection / transport layers (104B, 104G, 104R), light-emitting layers (105B, 105G, 105R), electron transport layers (108B, 108G, 108R) included in each EL layer (EL layer 103B, EL layer 103G, EL layer 103R) in each light-emitting device of this structure, and the first transport layer 104PS, active layer 105PS, buffer layer 220, and second transport layer 108PS included in the light-receiving layer 103PS in the light-receiving device, the ends (sides) of the processed EL layers have a shape including approximately the same surface (or, located on approximately the same plane). Furthermore, the sides (ends) of each layer of the light-receiving layer processed by pattern formation using photolithography have a shape including approximately the same surface (or, located on approximately the same plane).

[0391] Furthermore, because photolithography is used to form patterns during the separation and processing of the hole injection / transport layers (104B, 104G, 104R), light-emitting layers (105B, 105G, 105R), and electron transport layers (108B, 108G, 108R) included in each EL layer (EL layer 103B, EL layer 103G, EL layer 103R) in each light-emitting device, and the first transport layer 104PS, active layer 105PS, buffer layer 220, and second transport layer 108PS included in the light-receiving layer 103PS in the light-receiving device, each processed end (side) has a gap 580 between adjacent devices. In FIG10C, when the gap 580 is denoted as the distance SE between the EL layers or light-receiving layers of adjacent devices, a smaller distance SE can improve the aperture ratio and clarity. On the other hand, since a larger distance SE can tolerate the effects of process inhomogeneities between adjacent devices, the manufacturing yield can be improved. Since the light-emitting and light-receiving devices manufactured according to this specification are suitable for miniaturization processes, the distance SE between the EL layer or light-receiving layer of adjacent devices can be 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. Note that the distance SE is typically preferably 1 μm or more and 2 μm or less (e.g., 1.5 μm or nearby).

[0392] In this specification, devices manufactured using a metal mask or FMM (Fine Metal Mask) are sometimes referred to as MM (Metal Mask) structure devices. Furthermore, devices manufactured without a metal mask or FMM are sometimes referred to as MML (Metal Mask Less) structure devices. Because MML structure light-receiving devices are not manufactured using a metal mask, their pixel configuration and pixel shape design flexibility is greater than that of FMM or MM structure light-receiving devices.

[0393] The island-shaped EL layer in the MML structure light-emitting device is formed without using a patterned metal mask, but rather by processing the EL layer after it has been formed. Therefore, compared with conventional light-emitting devices, a light-emitting device with high definition or high aperture ratio can be achieved. Furthermore, because EL layers of each color can be formed separately, a light-emitting device with extremely vivid colors, extremely high contrast, and extremely high display quality can be achieved. In addition, by providing a sacrificial layer on the EL layer, damage to the EL layer during the manufacturing process can be reduced, thereby improving the reliability of the light-emitting device.

[0394] When the EL layer is processed into an island shape, a structure can be considered where the processing is performed directly above the light-emitting layer using photolithography. However, with this structure, the light-emitting layer may be damaged (due to processing defects, etc.), significantly reducing reliability. Therefore, when manufacturing a light-receiving device according to one embodiment of the present invention, it is preferable to use a method in which a sacrificial layer, etc., is formed on a second carrier transport layer or a second carrier injection layer located above the light-emitting layer, and the light-emitting layer is processed into an island shape. By employing this method, a display panel with high reliability can be provided.

[0395] Furthermore, in the light-emitting devices 550B, 550G, and 550R shown in FIG5A and FIG10C, the width of the EL layer (103B, 103G, 103R) is approximately equal to the width of the electrode (551B, 551G, 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. However, one embodiment of the present invention is not limited to this.

[0396] In light-emitting devices 550B, 550G, and 550R, the width of the EL layers (103B, 103G, 103R) may be smaller than the width of the electrodes (551B, 551G, 551R). Furthermore, in light-receiving device 550PS, the width of the light-receiving layer 103PS may be smaller than the width of the electrode 551PS. Figure 10D shows an example where the width of the EL layers (103B, 103G) in light-emitting devices 550B and 550G is smaller than the width of the electrodes (551B, 551G).

[0397] In light-emitting devices 550B, 550G, and 550R, the width of the EL layer (103B, 103G, 103R) may be greater than the width of the electrodes (551B, 551G, 551R). Furthermore, in light-receiving device 550PS, the width of the light-receiving layer 103PS may be greater than the width of the electrode 551PS. Figure 10E shows an example where the width of the EL layer 103R in light-emitting device 550R is greater than the width of the electrode 551R.

[0398] The structure shown in this embodiment can be used in appropriate combination with the structures shown in other embodiments.

[0399] Embodiment 4 In this embodiment, the light-receiving device 720 will be described with reference to FIGS. 11A to 13. Note that the light-receiving device 720 shown in FIGS. 11A to 13 is a light-receiving device that includes the light-receiving device and the light-emitting device shown in Embodiments 1 and 2. However, the light-receiving device 720 described in this embodiment can be applied to the display section of an electronic device or the like, and can therefore also be referred to as a display panel or display device. Furthermore, the light-receiving device 720 uses the light-emitting device as a light source and uses the light-receiving device to receive light from the light-emitting device.

[0400] Furthermore, the light-receiving device in this embodiment can be a high-resolution or large-sized light-receiving device. Therefore, the light-receiving device in this embodiment can be used as a display unit for devices such as: electronic devices with large screens, such as televisions, desktop or laptop computers, monitors for computers, digital signage, large game consoles such as pinball machines, etc.; digital cameras; digital video cameras; digital photo frames; mobile phones; portable game consoles; smartphones; watch-type terminals; tablet terminals; portable information terminals; audio playback devices, etc.

[0401] Figure 11A is a top view of the light-emitting device 720.

[0402] In FIG11A, the light-receiving device 720 has a structure for attaching the substrate 710 and the substrate 711. Furthermore, the light-receiving device 720 includes a display area 701, circuitry 704, and wiring 706, etc. Additionally, the display area 701 includes a plurality of pixels, and the pixel 703(i,j) shown in FIG11A includes the pixel 703(i+1,j) adjacent to pixel 703(i,j) shown in FIG11B.

[0403] Furthermore, as shown in FIG11A, the light-emitting device 720 mounts an IC (integrated circuit) 712 on a substrate 710 using a COG (Chip on Glass) or COF (Chip on Film) method. For example, an IC including a scan line drive circuit or a signal line drive circuit can be used as the IC712. FIG11A shows a structure in which an IC including a signal line drive circuit is used as the IC712 and a scan line drive circuit is used as the circuit 704.

[0404] Wiring 706 has the function of supplying signals and power to the display area 701 and circuit 704. These signals and power are input to wiring 706 from the outside via FPC (Flexible Printed Circuit) 713 or from IC 712. Alternatively, IC may not be provided in the light-receiving device 720. Furthermore, IC may also be mounted on the FPC via COF or similar methods.

[0405] Figure 11B shows pixels 703(i,j) and 703(i+1,j) of display area 701. That is, pixel 703(i,j) can include multiple sub-pixels, each including a light-emitting device that emits light of a different color. Furthermore, pixel 703(i,j) can also include multiple sub-pixels, each including a light-emitting device that emits light of the same color. For example, a pixel can include three types of sub-pixels. Examples of these three types of sub-pixels include sub-pixels of red (R), green (G), and blue (B), and sub-pixels of yellow (Y), cyan (C), and magenta (M). Alternatively, a pixel can include four types of sub-pixels. Examples of these four types of sub-pixels include sub-pixels of R, G, B, and white (W), and sub-pixels of R, G, B, and Y. Specifically, pixel 703(i,j) can be constructed using a blue pixel 702B(i,j), a green pixel 702G(i,j), and a red pixel 702R(i,j).

[0406] In addition, besides the sub-pixels that include the light-emitting device, the light-receiving device 720 also has sub-pixels that include the light-receiving device.

[0407] Figures 11C to 11E show examples of various layouts when pixel 703(i,j) includes sub-pixels 702PS(i,j) with light-receiving devices. The pixel arrangement shown in Figure 11C is a stripe arrangement, and the pixel arrangement shown in Figure 11D is a matrix arrangement. Furthermore, the pixel shown in Figure 11E has a structure in which three sub-pixels (sub-pixels R, G, and PS) are arranged vertically adjacent to a sub-pixel (sub-pixel B).

[0408] Furthermore, as shown in FIG11F, pixel 703(i,j) can also be constructed by adding an infrared-emitting sub-pixel 702IR(i,j) to the above-mentioned group. In the pixel shown in FIG11F, the three vertically longer sub-pixels G, B, and R are arranged horizontally, and the sub-pixel PS and the horizontally longer sub-pixel IR are arranged horizontally below them. Specifically, the sub-pixel 702IR(i,j) that emits light including light with wavelengths of 650nm or more and 1000nm or less can also be used for pixel 703(i,j). Furthermore, there is no particular limitation on the wavelength of light detected by sub-pixel 702PS(i,j), but the light-receiving device of sub-pixel 702PS(i,j) is preferably sensitive to the light emitted by the light-emitting device of sub-pixel 702R(i,j), sub-pixel 702G(i,j), sub-pixel 702B(i,j), or sub-pixel 702IR(i,j). For example, it is preferable to detect one or more of the following wavelength regions: blue, purple, blue-violet, green, yellow-green, yellow, orange, red, and light in the infrared wavelength region.

[0409] The arrangement of subpixels is not limited to the structures shown in Figures 11B to 11F, but various arrangement methods can be adopted. Examples of subpixel arrangements include stripe arrangement, S-stripe arrangement, matrix arrangement, Delta arrangement, Bayer arrangement, Pentile arrangement, etc.

[0410] Furthermore, examples of the top surface shape of a sub-pixel include triangles, quadrilaterals (including rectangles and squares), pentagons, and other polygonal shapes with rounded corners, as well as ellipses or circles. Here, the top surface shape of the sub-pixel corresponds to the top surface shape of the light-emitting area of ​​the light-emitting device.

[0411] In a pixel structure that includes a light-emitting device and a light-receiving device, the pixel has a light-receiving function, so it is possible to detect the contact or proximity of an object while displaying an image. For example, not only can all sub-pixels included in the light-emitting device display images, but some sub-pixels can also emit light as a light source and cause other sub-pixels to display images.

[0412] Furthermore, the light-receiving area of ​​sub-pixel 702PS(i,j) is preferably smaller than the light-emitting area of ​​other sub-pixels. The smaller the light-receiving area, the narrower the imaging range, which can suppress blurring of the imaging result and improve the resolution. Therefore, by using sub-pixel 702PS(i,j), high-definition or high-resolution imaging can be performed. For example, sub-pixel 702PS(i,j) can be used for personal identification using fingerprints, palm prints, irises, vein shapes (including vein shapes and artery shapes), or faces.

[0413] Furthermore, sub-pixels 702PS(i,j) can be used in touch sensors (also known as direct touch sensors) or air touch sensors (also known as hover sensors, hover touch sensors, non-contact sensors, contactless sensors, etc.). For example, sub-pixels 702PS(i,j) are preferably used to detect infrared light. Thus, touch can be detected even in the dark.

[0414] Here, a touch sensor or an air touch sensor can detect the approach or contact of an object (fingers, hands, or pens, etc.). A touch sensor can detect an object by having the light-emitting device in direct contact with it. Furthermore, an air touch sensor can detect an object even if it is not in contact with the light-emitting device. For example, preferably, the light-emitting device can detect the object within a distance of 0.1 mm to 300 mm, more preferably 3 mm to 50 mm, between the light-emitting device and the object. By adopting this structure, operation can be performed without the object directly contacting the light-emitting device; in other words, the light-emitting device can be operated in a non-contact (contactless) manner. By adopting the above structure, the risk of the light-emitting device becoming dirty or damaged, or the object operating the light-emitting device without directly contacting stains (e.g., garbage, bacteria, or viruses) attached to it, can be reduced.

[0415] For high-definition imaging, sub-pixels 702PS(i,j) are preferably placed in all the pixels included in the light-emitting device. On the other hand, sub-pixels 702PS(i,j) used for touch sensors or air touch sensors do not require high detection accuracy compared to those used for fingerprint scanning, so sub-pixels 702PS(i,j) can be placed in only a portion of the pixels included in the light-emitting device. By making the number of sub-pixels 702PS(i,j) included in the light-emitting device less than the number of sub-pixels 702R(i,j), the detection speed can be improved.

[0416] Next, an example of a pixel circuit including a sub-pixel with a light-emitting device will be described with reference to FIG12A. The pixel circuit 530 shown in FIG12A includes a light-emitting device (EL) 550, transistors M15, M16, and M17, and a capacitor C3. As the light-emitting device 550, a light-emitting diode can be used. In particular, as the light-emitting device 550, the light-emitting device described in Embodiments 1 and 2 is preferred.

[0417] In Figure 12A, the gate of transistor M15 is electrically connected to wiring VG, one of its source and drain is electrically connected to wiring VS, and the other of its source and drain is electrically connected to one electrode of capacitor C3 and the gate of transistor M16. One of the source and drain of transistor M16 is electrically connected to wiring V4, and the other of its source and drain is electrically connected to the anode of light-emitting device 550 and one of the source and drain of transistor M17. The gate of transistor M17 is electrically connected to wiring MS, and the other of its source and drain is electrically connected to wiring OUT2. The cathode of light-emitting device 550 is electrically connected to wiring V5.

[0418] Wiring V4 and wiring V5 are each supplied with a constant potential. The anode side and cathode side of the light-emitting device 550 can be set to a high potential and a potential lower than that of the anode side, respectively. Transistor M15 is supplied with a signal controlled by wiring VG and is used as a selection transistor to control the selection state of the pixel circuit 530. In addition, transistor M16 is used as a drive transistor to control the current flowing through the light-emitting device 550 according to the potential supplied to the gate. When transistor M15 is in the on state, the potential supplied to wiring VS is supplied to the gate of transistor M16, and the brightness of the light-emitting device 550 can be controlled according to this potential. Transistor M17 is supplied with a signal controlled by wiring MS and has the function of outputting the potential between transistor M16 and the light-emitting device 550 to the outside through wiring OUT2.

[0419] The transistors M15, M16 and M17 included in the pixel circuit 530 of FIG12A, and the transistors M11, M12, M13 and M14 included in the pixel circuit 531 of FIG12B are preferably transistors using a semiconductor layer comprising a metal oxide (oxide semiconductor) to form their channels.

[0420] Using metal oxide transistors with a wider band gap and lower carrier density than silicon allows for extremely small off-state currents. Consequently, because of their small off-state current, the charge stored in the capacitor connected in series with the transistor can be maintained for a long period. Therefore, in particular, transistors M11, M12, and M15 connected in series with capacitor C2 or capacitor C3 are preferably transistors containing oxide semiconductors. Furthermore, by using transistors that similarly utilize oxide semiconductors in other transistors, manufacturing costs can be reduced.

[0421] Furthermore, transistors M11 to M17 may also be transistors whose semiconductor forming their channels comprises silicon. In particular, it is preferable to use highly crystalline silicon such as monocrystalline silicon or polycrystalline silicon, as this can achieve high field-efficiency mobility and higher operating speed.

[0422] In addition, one or more of transistors M11 to M17 may be transistors containing oxide semiconductors, and the other transistors may be transistors containing silicon.

[0423] Next, an example of a sub-pixel having a light-receiving device will be described with reference to FIG12B. The pixel circuit 531 shown in FIG12B includes a light-receiving device (PD) 560, transistors M11, M12, M13, M14, and capacitor C2. Here, an example using a photodiode as the light-receiving device (PD) 560 is shown.

[0424] In Figure 12B, the anode of the photodetector (PD) 560 is electrically connected to wiring V1, and the cathode is electrically connected to one of the source and drain electrodes of transistor M11. The gate of transistor M11 is electrically connected to wiring TX, and the other of its source and drain electrodes is electrically connected to one electrode of capacitor C2, one of the source and drain electrodes of transistor M12, and the gate of transistor M13. The gate of transistor M12 is electrically connected to wiring RES, and the other of its source and drain electrodes is electrically connected to wiring V2. One of the source and drain electrodes of transistor M13 is electrically connected to wiring V3, and the other of its source and drain electrodes is electrically connected to one of the source and drain electrodes of transistor M14. The gate of transistor M14 is electrically connected to wiring SE, and the other of its source and drain electrodes is electrically connected to wiring OUT1.

[0425] Wiring V1, wiring V2, and wiring V3 are each supplied with a constant potential. When the photodetector (PD) 560 is driven with a reverse bias, a potential higher than that of wiring V1 is supplied to wiring V2. Transistor M12 is controlled by a signal supplied to wiring RES and has the function of resetting the potential of the node connected to the gate of transistor M13 to the potential supplied to wiring V2. Transistor M11 is controlled by a signal supplied to wiring TX and has the function of controlling the timing of the potential changes of the above-mentioned nodes according to the current flowing through the photodetector (PD) 560. Transistor M13 is used as an amplifying transistor for outputting the potential of the above-mentioned nodes. Transistor M14 is controlled by a signal supplied to wiring SE and is used as a selection transistor, which is used to read the output based on the potential of the above-mentioned nodes using an external circuit connected to wiring OUT1.

[0426] In Figures 12A and 12B, an n-channel transistor is used as the transistor, but a p-channel transistor can also be used.

[0427] The transistors included in pixel circuit 530 and pixel circuit 531 are preferably arranged on the same substrate. More preferably, the transistors included in pixel circuit 530 and pixel circuit 531 are mixed and formed in one region and arranged periodically.

[0428] Furthermore, it is preferable to provide one or more layers, including one or both of transistors and capacitors, at a position overlapping with the light-receiving device (PD) 560 or the light-emitting device (EL) 550. This reduces the effective area occupied by each pixel circuit, thereby enabling a high-definition light-receiving or display section.

[0429] Next, FIG12C shows an example of a specific structure of a transistor that can be applied to the pixel circuit described with reference to FIG12A and FIG12B. Note that, as a transistor, a bottom-gate transistor or a top-gate transistor, etc., can be appropriately used.

[0430] The transistor shown in FIG12C 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, for example, on the insulating film 501C. In addition, the transistor includes an insulating film 516 (insulating film 516A and insulating film 516B) and an insulating film 518.

[0431] The semiconductor film 508 includes 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 includes a region 508C between the regions 508A and 508B.

[0432] The conductive film 504 includes a region that overlaps with the region 508C, and the conductive film 504 has the function of a gate electrode.

[0433] The insulating film 506 includes a region sandwiched between the semiconductor film 508 and the conductive film 504. The insulating film 506 functions as a first gate insulating film.

[0434] The conductive film 512A has one of the functions of a source electrode and a drain electrode, and the conductive film 512B has the other of the functions of a source electrode and a drain electrode.

[0435] Furthermore, the conductive film 524 can be used for a transistor. The conductive film 524 includes a region in which a semiconductor film 508 is sandwiched between it and the conductive film 504. The conductive film 524 functions as a second gate electrode. An insulating film 501D is sandwiched between the semiconductor film 508 and the conductive film 524 and functions as a second gate insulating film.

[0436] The insulating film 516 is used, for example, as a protective film covering the semiconductor film 508. Specifically, for example, a film containing silicon oxide film, silicon oxynitride film, silicon oxynitride film, silicon nitride film, aluminum oxide film, hafnium oxide film, yttrium oxide film, zirconium oxide film, gallium oxide film, tantalum oxide film, magnesium oxide film, lanthanum oxide film, cerium oxide film, or neodymium oxide film can be used for the insulating film 516.

[0437] For example, it is preferable to use a material capable of suppressing the diffusion of oxygen, hydrogen, water, alkali metals, alkaline earth metals, etc., in the insulating film 518. Specifically, as the insulating film 518, silicon nitride, silicon oxynitride, aluminum nitride, aluminum oxynitride, etc., can be used, for example. Furthermore, as for silicon oxynitride and aluminum oxynitride, it is preferable that the number of nitrogen atoms is greater.

[0438] In the process of forming a semiconductor film for a transistor used in a pixel circuit, a semiconductor film for a transistor used in a driving circuit can be formed. For example, a semiconductor film having the same composition as the semiconductor film in the transistor of the pixel circuit can be used in a driving circuit.

[0439] In addition, semiconductors containing Group 14 elements can be used in semiconductor film 508. Specifically, semiconductors containing silicon can be used in semiconductor film 508.

[0440] Furthermore, hydrogenated amorphous silicon can be used in the semiconductor film 508. Alternatively, microcrystalline silicon or the like can be used in the semiconductor film 508. Thus, for example, a light-emitting device with less display non-uniformity can be provided compared to devices (including light-emitting devices, display panels, display devices, and light-receiving devices) that use polycrystalline silicon in the semiconductor film 508. Alternatively, it is easier to scale up the device.

[0441] Furthermore, polycrystalline silicon can be used in the semiconductor film 508. This allows, for example, a higher field-effect mobility than that achieved with a transistor using hydrogenated amorphous silicon in the semiconductor film 508. Alternatively, for example, a higher driving capability than that achieved with a transistor using hydrogenated amorphous silicon in the semiconductor film 508 can be achieved. Alternatively, for example, a higher pixel aperture ratio than that achieved with a transistor using hydrogenated amorphous silicon in the semiconductor film 508 can be achieved.

[0442] Alternatively, for example, higher reliability can be achieved than that of transistors using hydrogenated amorphous silicon in semiconductor film 508.

[0443] Alternatively, for example, the temperature required to manufacture the transistor can be lower than that required for a transistor using single-crystal silicon.

[0444] Alternatively, the semiconductor film for the transistor used in the driving circuit and the semiconductor film for the transistor used in the pixel circuit can be formed using the same process. Alternatively, the driving circuit can be formed on the same substrate as the substrate on which the pixel circuit is formed. Alternatively, the number of components constituting the electronic device can be reduced.

[0445] Furthermore, monocrystalline silicon can be used in the semiconductor film 508. This, for example, allows for higher resolution than that achieved with hydrogenated amorphous silicon in the semiconductor film 508. Alternatively, for example, it allows for a light-emitting device with less display inhomogeneity compared to a light-emitting device using polycrystalline silicon in the semiconductor film 508. Alternatively, for example, it allows for the provision of smart glasses or head-mounted displays.

[0446] Furthermore, metal oxides can be used in the semiconductor film 508. Therefore, compared to pixel circuits using transistors with amorphous silicon in the semiconductor film, the time during which the pixel circuit can maintain the image signal can be extended. Specifically, flickering can be suppressed, and a selection signal can be supplied at a frequency of less than 30 Hz, preferably less than 1 Hz, and more preferably less than 1 time / min. As a result, user fatigue of the electronic device can be reduced. Furthermore, power consumption for driving can be reduced.

[0447] In addition, oxide semiconductors can be used in semiconductor film 508. Specifically, oxide semiconductors containing indium, oxide semiconductors containing indium, gallium and zinc, or oxide semiconductors containing indium, gallium, zinc and tin can be used in semiconductor film 508.

[0448] By using oxide semiconductors in the semiconductor film, a transistor with a smaller leakage current in the off state can be obtained compared to a transistor using amorphous silicon in the semiconductor film. Therefore, it is preferable to use a transistor using oxide semiconductors in the semiconductor film as a switch, etc. Note that a circuit using an oxide semiconductor transistor in the semiconductor film as a switch can maintain the potential of the floating node for a longer period of time compared to a circuit using an amorphous silicon transistor in the semiconductor film as a switch.

[0449] When using oxide semiconductors as semiconductor films, the light-emitting device 720 has a structure in which oxide semiconductors are used as semiconductor films and includes a light-emitting device with an MML (non-fine metal mask) structure. By adopting this structure, the leakage current flowing through the transistors and the leakage current flowing between adjacent light-emitting devices (also called lateral leakage current, side leakage current, etc.) can be extremely low. Furthermore, by adopting the above structure, when an image is displayed on the display device, the viewer can observe one or more of the following: image sharpness, image sharpness, high color saturation, and high contrast. In addition, by adopting a structure with extremely low leakage current flowing through the transistors and extremely low lateral leakage current between light-emitting devices, a display with minimal light leakage (so-called whitening) that can occur when displaying black (also called pure black display) can be achieved.

[0450] In particular, when the above-described SBS structure is used in a light-emitting device with an MML structure, the layers disposed between the light-emitting devices (e.g., organic layers commonly used between the light-emitting devices, also known as shared layers) are separated, thereby enabling a display with no or very little side leakage.

[0451] Next, a cross-sectional view of the light-receiving device is shown. FIG13 is a cross-sectional view of the light-receiving device shown in FIG11A.

[0452] Figure 13 is a cross-sectional view of a portion of the area including FPC713 and wiring 706, and a portion of the display area 701 including pixels 703(i,j).

[0453] In FIG13, the light-emitting device 700 includes a functional layer 520 between the first substrate 510 and the second substrate 770. In addition to the transistors (M11, M12, M13, M14, M15, M16, M17) and capacitors (C2, C3) illustrated in FIGS. 12A to 12C, the functional layer 520 also includes wiring (VS, VG, V1, V2, V3, V4, V5) that electrically connects them. FIG13 shows the structure of the functional layer 520 including pixel circuits 530X(i,j), pixel circuits 530S(i,j), and driving circuit GD, but is not limited to this structure.

[0454] Pixel circuits formed in the functional layer 520 (e.g., pixel circuits 530X(i,j) and 530S(i,j) shown in FIG. 13) are electrically connected to light-emitting devices and light-receiving devices formed on the functional layer 520 (e.g., light-emitting devices 550X(i,j) and 550S(i,j) shown in FIG. 13). Specifically, the light-emitting device 550X(i,j) is electrically connected to the pixel circuit 530X(i,j) via wiring 591X, and the light-receiving device 550S(i,j) is electrically connected to the pixel circuit 530S(i,j) via wiring 591S. Furthermore, an insulating layer 705 is provided on the functional layer 520, the light-emitting devices, and the light-receiving devices, and the insulating layer 705 has the function of bonding the second substrate 770 to the functional layer 520.

[0455] Note that the second substrate 770 can be a substrate having touch sensors in a matrix configuration. For example, a substrate including an electrostatic capacitive touch sensor or an optical touch sensor can be used as the second substrate 770. Thus, the light-emitting device of one embodiment of the present invention can be used as a touch panel.

[0456] The structure shown in this embodiment can be used in appropriate combination with the structures shown in other embodiments.

[0457] Embodiment 5 In this embodiment, the structure of an electronic device according to an embodiment of the present invention will be described with reference to FIGS. 14A to 16B. Furthermore, a portion of the electronic device shown in this embodiment may include a light-receiving device as an embodiment of the present invention.

[0458] Figures 14A to 16B are diagrams illustrating the structure of an electronic device according to one embodiment of the present invention. Figure 14A is a block diagram of the electronic device, and Figures 14B to 14E are perspective views illustrating the structure of the electronic device. Figures 15A to 15E are perspective views illustrating the structure of the electronic device. Figures 16A and 16B are perspective views illustrating the structure of the electronic device.

[0459] The electronic device 5200B described in this embodiment includes an arithmetic unit 5210 and an input / output unit 5220 (see FIG14A).

[0460] The computing device 5210 has the function of being supplied with operation data and the function of supplying image data according to the operation data.

[0461] The input / output device 5220 includes a display unit 5230, an input unit 5240, a detection unit 5250, and a communication unit 5290, and has the functions of supplying operation data and receiving image data. In addition, the input / output device 5220 has the functions of supplying detection data, supplying communication data, and receiving communication data.

[0462] The input unit 5240 has the function of supplying operation data. For example, the input unit 5240 supplies operation data according to the operation of the user of the electronic device 5200B.

[0463] Specifically, keyboards, hardware buttons, pointing devices, touch sensors, illuminance sensors, camera devices, audio input devices, gaze input devices, posture detection devices, etc., can be used in the input unit 5240.

[0464] The display unit 5230 includes a display panel and has the function of displaying image data. For example, the display panel described in Embodiment 3 can be used in the display unit 5230.

[0465] The testing unit 5250 has the function of supplying testing data. For example, it has the function of supplying testing data by testing the environment surrounding the electronic device.

[0466] Specifically, illuminance sensors, camera devices, posture detection devices, pressure sensors, human body sensors, etc., can be used in the detection unit 5250.

[0467] The communications unit 5290 has the function of supplying communications data and the function of supplying communications data. For example, it has the function of connecting with other electronic devices or communications networks via wireless or wired communications. Specifically, it has the functions of wireless local area network communications, telephone communications, and short-range wireless communications.

[0468] Figure 14B shows an electronic device having an outline along a cylindrical column or the like. As an example, a digital signage unit could be used. The display panel of one embodiment of the present invention can be used in the display unit 5230. Note that it may also have a function to change the display method according to the illumination of the usage environment. Furthermore, it may have a function to sense the presence of a human body and change the displayed content. Therefore, it can be installed, for example, on a column of a building. Alternatively, it can display advertisements or guides, etc. Alternatively, it can be used for digital signage units, etc.

[0469] Figure 14C illustrates an electronic device with the function of generating image data based on the trajectory of an indicator used by the user. Examples include electronic blackboards, electronic message boards, and digital signage. 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 display panel.

[0470] Figure 14D illustrates an electronic device that can receive data from other devices and display it on the display unit 5230. Wearable electronic devices can be cited as an example. Specifically, several options can be displayed, or the user can select several options and reply to the sender of the data. Alternatively, for example, it has a function to change the display method according to the illumination of the usage environment. This, for example, can reduce the power consumption of the wearable electronic device. Or, for example, it can display images on the wearable electronic device in a way that allows for suitable use even in environments with strong external light, such as outdoors on a sunny day.

[0471] FIG14E shows an electronic device including a display section 5230 having a curved surface that gently curves along the side of the casing. As an example, a mobile phone can be cited. Furthermore, the display section 5230 includes a display panel, which, for example, has the function of displaying on its front, side, top, and back. Thus, for example, data can be displayed not only on the front of the mobile phone, but also on the side, top, and back of the mobile phone.

[0472] Figure 15A shows an electronic device that can receive data from the Internet and display it on the display unit 5230. A smartphone can be cited as an example. For instance, a notification can be viewed on the display unit 5230. Alternatively, the notification can be sent to another device. Or, for example, it has a function to change the display method according to the ambient light level. This reduces the power consumption of the smartphone. Or, for example, it can display images on the smartphone in a way that allows for suitable use even in environments with strong external light, such as outdoors on a sunny day.

[0473] Figure 15B shows an electronic device that can use a remote control as an input unit 5240. As an example, a television system can be cited. Alternatively, data can be received from a radio station or the Internet and displayed on the display unit 5230. Furthermore, the detection unit 5250 can capture images of the user. Furthermore, the user's image can be transmitted. Furthermore, the user's viewing history can be obtained and provided to a cloud service. Furthermore, recommendation information can be obtained from the cloud service and displayed on the display unit 5230. Furthermore, programs or moving images can be displayed based on the recommendation information. Furthermore, for example, it has a function to change the display method according to the ambient light level. Thus, images can be displayed on the television system in a way that allows for suitable use even in environments with strong outdoor light entering the room on sunny days.

[0474] Figure 15C shows an electronic device that can receive teaching materials from the Internet and display them on the display unit 5230. A tablet computer or similar device can be used as an example. Alternatively, a report can be entered using the input unit 5240 and sent to the Internet. Furthermore, the grading results or evaluations of the report can be obtained from a cloud service and displayed on the display unit 5230. Additionally, appropriate teaching materials can be selected based on the evaluations and displayed on the display unit 5230.

[0475] For example, image signals can be received from other electronic devices and displayed on the display unit 5230. Furthermore, the display unit 5230 can be rested on a stand or the like and used as a secondary display. Thus, for example, images can be displayed on the tablet computer in a way that allows for suitable use even in bright outdoor environments such as on a sunny day.

[0476] Figure 15D shows an electronic device including multiple display units 5230. As an example, a digital camera can be cited. For example, an image captured using the detection unit 5250 can be displayed on the display unit 5230. Furthermore, the captured image can be displayed on the detection unit. Furthermore, the captured image can be modified using the input unit 5240. Furthermore, text can be added to the captured image. Furthermore, it can be sent to the Internet. Furthermore, it has a function to change shooting conditions according to the ambient light level. Thus, for example, the subject can be displayed on the digital camera in a way that allows for suitable viewing even in bright outdoor environments such as on a sunny day.

[0477] Figure 15E illustrates an electronic device that can control other electronic devices by using other electronic devices as slaves and using the electronic device of this embodiment as a master. As an example, a portable personal computer can be cited. For instance, a portion of the image data can be displayed on the display unit 5230, and another portion of the image data can be displayed on the display unit of another electronic device. Furthermore, an image signal can be supplied. Additionally, data written from the input unit of another electronic device can be obtained using the communication unit 5290. Thus, for example, a portable personal computer can be used to utilize a larger display area.

[0478] Figure 16A shows an electronic device including a detection unit 5250 that detects acceleration or orientation. An example could be a goggle-type electronic device. Alternatively, the detection unit 5250 can provide data on the user's position or the direction the user is facing. Furthermore, the electronic device can generate image data for the right eye and image data for the left eye based on the user's position or the direction the user is facing. Additionally, the display unit 5230 includes a display area for the right eye and a display area for the left eye. Thus, for example, a realistic virtual reality space image can be displayed on the goggle-type electronic device.

[0479] Figure 16B shows an electronic device including a camera and a detection unit 5250 for detecting acceleration or orientation. An example could be an eyeglass-type electronic device. Alternatively, the detection unit 5250 can provide data on the user's position or the direction the user is facing. Furthermore, the electronic device can generate image data based on the user's position or the direction the user is facing. Thus, for example, data can be added to and displayed on a real-world landscape. Furthermore, images of augmented reality can be displayed on an eyeglass-type electronic device.

[0480] This embodiment can be appropriately combined with other embodiments shown in this specification. Examples

[0481] In this embodiment, a light-receiving device (device 1 to device 8) according to one embodiment of the present invention described in the embodiments is manufactured and the results of evaluating its characteristics are explained.

[0482] The following shows the structural formulas of the organic compounds used in devices 1 to 8.

[0483] [Chemical Formula 65]

[0484] (Manufacturing method of device 1) As shown in FIG17, device 1 has the following structure: a hole injection layer 911, a hole transport layer 912, an active layer 913, a buffer layer 920, 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.

[0485] First, a reflective film is formed on a glass substrate 900. Specifically, an alloy containing silver (Ag), palladium (Pd), and copper (Cu) (abbreviated as APC) is used as the target material, and a reflective film with a thickness of 100 nm is formed by sputtering. Then, indium tin oxide (ITSO) containing silicon or silicon oxide is deposited by sputtering, thereby forming a first electrode 901. The first electrode 901 has a thickness of 100 nm and an electrode area of ​​4 mm² (2 mm × 2 mm).

[0486] Next, as a pretreatment for forming the light-receiving device on the substrate, the substrate surface is washed with water and baked at 200°C for 1 hour. Then, the substrate is placed in a vacuum evaporation apparatus whose internal pressure is reduced to about 10⁻⁴ Pa, and vacuum baked at 180°C for 60 minutes in the heating chamber of the vacuum evaporation apparatus. Then, it is allowed to cool to below 30°C.

[0487] Next, the substrate on which the first electrode 901 is formed is fixed on a substrate support provided in a vacuum evaporation apparatus with the surface on which the first electrode 901 is formed facing downward. On the first electrode 901, N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviated as: BBABnf) and an electron acceptor material (OCHD-003) with a molecular weight of 672 containing fluorine are co-deposited by resistance heating evaporation method. This forms a hole injection layer 911.

[0488] Next, BBABnf is deposited on the hole injection layer 911 with a thickness of 40 nm to form the hole transport layer 912.

[0489] Next, Rubrene is deposited on the hole transport layer 912 with a thickness of 42 nm, and then N,N'-bis(2-ethylhexyl)-3,4,9,10-perylenetetracarboxylic acid diimide (abbreviated as EtHex-PTCDI) is deposited on the hole transport layer 912 with a thickness of 18 nm, thereby forming the active layer 913.

[0490] Next, pyrazine[2,3-f][1,10]phenanthroline-2,3-dicarboxynitrile (PPDN) is deposited on the active layer 913 with a thickness of 15 nm to form the buffer layer 920.

[0491] Next, 2-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoline (abbreviation: 2mDBTBPDBq-II) is deposited on the buffer layer 920 with a thickness of 10 nm, and then 2,9-bis(naphthyl-2-yl)-4,7-diphenyl-1,10-phenoline (abbreviation: NBPhen) is deposited with a thickness of 10 nm, thereby forming the electron transport layer 914.

[0492] Next, lithium fluoride (LiF) is deposited on the electron transport layer 914 with a thickness of 1 nm to form an electron injection layer 915.

[0493] Next, Ag and Mg are co-deposited on the electron injection layer 915 in a volume ratio of Ag:Mg = 1:0.1 and a thickness of 10 nm to form a second electrode 903, thereby manufacturing device 1. Note that the second electrode 903 is a semi-transmissive-semi-reflective electrode that has the function of reflecting light and transmitting light.

[0494] Next, the manufacturing methods of devices 2 to 8 will be described.

[0495] (Manufacturing method of device 2) The difference between device 2 and device 1 lies in the thickness of the electron transport layer 914. That is, in the manufacturing of device 2, except for the following points, it is the same as device 1: 2mD BTB PDBq-II is deposited on the buffer layer 920 with a thickness of 10nm, and then NBPhen is deposited with a thickness of 20nm, thereby forming the electron transport layer 914.

[0496] (Manufacturing method of device 3) The difference between device 3 and device 1 lies in the thickness of each layer constituting the active layer 913. That is, in the manufacturing of device 3, except for the following points, it is the same as device 1: Rubrene is deposited on the hole transport layer 912 with a thickness of 30 nm, and then EtHex-PTCDI is deposited with a thickness of 30 nm, thereby forming the active layer 913.

[0497] (Manufacturing method of device 4) The difference between device 4 and device 3 lies in the thickness of the electron transport layer 914. That is, in the manufacturing of device 4, except for the following points, it is the same as device 3: 2mD BTB PDBq-II is deposited on the buffer layer 920 with a thickness of 10nm, and then NBPhen is deposited with a thickness of 20nm, thereby forming the electron transport layer 914.

[0498] (Manufacturing method of device 5) The difference between device 5 and device 1 is that the active layer 913 is a hybrid layer. That is, in the manufacturing of device 5, except for the following point, it is the same as device 1: Rubrene and EtHex-PTCDI are co-deposited on the hole transport layer 912 in a Rubrene:EtHex-PTCDI ratio of 0.7:0.3 (weight ratio) and a thickness of 60 nm, thereby forming the active layer 913.

[0499] (Manufacturing method of device 6) The difference between device 6 and device 5 lies in the thickness of the electron transport layer 914. That is, in the manufacturing of device 6, except for the following points, it is the same as device 5: 2mD BTB PDBq-II is deposited on the buffer layer 920 with a thickness of 10nm, and then NBPhen is deposited with a thickness of 20nm, thereby forming the electron transport layer 914.

[0500] (Manufacturing method of device 7) The difference between device 7 and device 5 lies in the mixing ratio of the active layer 913. That is, in the manufacturing of device 7, except for the following point, it is the same as device 5: Rubrene and EtHex-PTCDI are co-deposited on the hole transport layer 912 in a Rubrene:EtHex-PTCDI ratio of 0.5:0.5 (weight ratio) and a thickness of 60 nm, thereby forming the active layer 913.

[0501] (Manufacturing method of device 8) The difference between device 8 and device 7 lies in the thickness of the electron transport layer 914. That is, in the manufacturing of device 8, except for the following points, it is the same as device 7: 2mD BTB PDBq-II is deposited on the buffer layer 920 with a thickness of 10nm, and then NBPhen is deposited with a thickness of 20nm, thereby forming the electron transport layer 914.

[0502] The following shows the component structure of the above-mentioned devices 1 to 8.

[0503] [Table 1]

[0504] In addition, the LUMO energy levels of the materials used in the active layer, buffer layer, and electron transport layer of the above-mentioned devices 1 to 8 are shown below. The LUMO energy levels were investigated by cyclic voltammetry (CV) measurement. In the measurement, an electrochemical analyzer (manufactured by BAS Inc., model: ALS type 600A or 600C) was used.

[0505] [Table 2]

[0506] Next, various measurements are performed on devices 1 to 8 manufactured by the above manufacturing method.

[0507] <Spectroscopic Sensitivity> Figure 18 shows the wavelength dependence of the external quantum efficiency (EQE) of devices 1 and 2, Figure 21 shows the wavelength dependence of the EQE of devices 3 and 4, Figure 24 shows the wavelength dependence of the EQE of devices 5 and 6, and Figure 27 shows the wavelength dependence of the EQE of devices 7 and 8. EQE measurements were performed under a radiation irradiance of 12.5 μW / cm² with varying voltage and wavelength. In Figures 18, 21, 24, and 27, the horizontal axis represents wavelength λ, and the vertical axis represents EQE. As shown in Figures 18, 21, 24, and 27, devices 1 to 8 can be confirmed to have high photosensitive sensitivity to visible light.

[0508] <Current Density-Voltage Characteristics> Figures 19 and 20 show the current density-voltage characteristics of devices 1 and 2, Figures 22 and 23 show the current density-voltage characteristics of devices 3 and 4, Figures 25 and 26 show the current density-voltage characteristics of devices 5 and 6, and Figures 28 and 29 show the current density-voltage characteristics of devices 7 and 8. Measurements were performed under conditions of monochromatic light (referred to as Photo) with a wavelength λ of 550 nm irradiance at 12.5 μW / cm² and in darkness (referred to as Dark). In Figures 19, 20, 22, 23, 25, 26, 28, and 29, the horizontal axis represents voltage V, and the vertical axis represents current density.

[0509] As shown in Figures 19, 20, 22, 23, 25, 26, 28, and 29, it can be confirmed that the current is amplified due to light irradiation in devices 1 to 8. Furthermore, it can be confirmed that the current amplification during light irradiation is caused by low voltage, and the current saturation characteristic is very high. Additionally, it can be confirmed that the dark current in devices 1 to 8 is low. [Simplified Explanation of the Diagram]

[0036] [Figures 1A] to [Figures 1D] are diagrams illustrating a light-receiving device according to one embodiment of the present invention; [Figures 2A] to [Figures 2C] are diagrams illustrating a light-emitting device according to one embodiment of the present invention; [Figures 3A] and [Figures 3B] are diagrams illustrating a light-emitting device according to one embodiment of the present invention; [Figures 4A] to [Figures 4E] are diagrams illustrating the structure of a light-emitting device according to an embodiment; [Figures 5A] to [Figures 5D] are diagrams illustrating a light-emitting device according to an embodiment; [Figures 6A] to [Figures 6C] are diagrams illustrating a method of manufacturing a light-emitting device according to an embodiment; [Figures 7A] to [Figures 7C] are diagrams illustrating a method of manufacturing a light-emitting device according to an embodiment; [Figures 8A] to [Figures 8C] are diagrams illustrating a method of manufacturing a light-emitting device according to an embodiment; [Figures 9A] to [Figures 9D] are diagrams illustrating a method of manufacturing a light-emitting device according to an embodiment; [Figures 10A] to [Figures 10E] are diagrams illustrating a method of manufacturing a light-emitting device according to an embodiment; [Figs. 11A] to [Figs. 11F] are diagrams illustrating the apparatus and pixel layout according to the embodiment; [Figs. 12A] to [Figs. 12C] are diagrams illustrating the pixel circuit according to the embodiment; [Fig. 13] is a diagram illustrating the light-receiving device according to the embodiment; [Figs. 14A] to [Figs. 14E] are diagrams illustrating the electronic device according to the embodiment; [Figs. 15A] to [Figs. 15E] are diagrams illustrating the electronic device according to the embodiment; [Figs. 16A] and [Figs. 16B] are diagrams illustrating the electronic device according to the embodiment; [Fig. 17] is a diagram illustrating the structure of devices 1 to 8; [Fig. 18] is a diagram illustrating the spectral sensitivity of devices 1 and 2; [Fig. 19] is a diagram illustrating the voltage-current density characteristics of devices 1 and 2 under illumination; [Fig. 20] is a diagram illustrating the voltage-current density characteristics of devices 1 and 2 in the dark; [Fig. 21] is a diagram illustrating the spectral sensitivity of devices 3 and 4. [Figure 22] is a graph illustrating the voltage-current density characteristics of devices 3 and 4 under illumination; [Figure 23] is a graph illustrating the voltage-current density characteristics of devices 3 and 4 in the dark; [Figure 24] is a graph illustrating the spectroscopic sensitivity of devices 5 and 6; [Figure 25] is a graph illustrating the voltage-current density characteristics of devices 5 and 6 under illumination; [Figure 26] is a graph illustrating the voltage-current density characteristics of devices 5 and 6 in the dark; [Figure 27] is a graph illustrating the spectroscopic sensitivity of devices 7 and 8; [Figure 28] is a graph illustrating the voltage-current density characteristics of devices 7 and 8 under illumination; [Figure 29] is a graph illustrating the voltage-current density characteristics of devices 7 and 8 in the dark.

Claims

1. A light-receiving device, comprising: A light-receiving layer between a pair of electrodes, wherein the light-receiving layer includes an active layer, a buffer layer and an electron transport layer, the buffer layer is located between the active layer and the electron transport layer and is in contact with the active layer, the active layer contains a first organic compound, the buffer layer contains a second organic compound, the electron transport layer contains a third organic compound, and the LUMO energy level of the second organic compound is higher than that of the first organic compound and lower than that of the third organic compound.

2. The light-receiving device of claim 1, wherein the difference between the LUMO energy level of the second organic compound and the LUMO energy level of the first organic compound is less than 0.5 eV.

3. The light-receiving device of claim 1, wherein the difference between the LUMO energy level of the second organic compound and the LUMO energy level of the third organic compound is less than 1.0 eV.

4. The light-receiving device of claim 1, wherein the LUMO energy level of the second organic compound is above -4.5 eV and below -3.0 eV.

5. A light-receiving device, comprising: Such as the light-receiving device in request item 1; And light-emitting devices.

6. The light-receiving device of claim 1, wherein the second organic compound is a heteroaromatic compound having an electron-withdrawing group.

7. The light-receiving device of claim 1, wherein the second organic compound has a plurality of cyano groups.

8. The light-receiving device of claim 6, wherein the heteroaromatic compound has a fused heteroaromatic ring.

9. The light-receiving device as claimed in claim 1, wherein the third organic compound is a π-electron-deficient heteroaromatic compound.

10. The light-receiving device of claim 1, wherein the third organic compound is one of a metal complex comprising a quinoline skeleton, a metal complex comprising a benzoquinoline skeleton, a metal complex comprising a acetazole skeleton, a metal complex comprising a thiazole skeleton, an acediazole derivative, a triazole derivative, an imidazole derivative, an acetazole derivative, a thiazole derivative, a phenoline derivative, a quinoline derivative comprising a quinoline ligand, a benzoquinoline derivative, a quinoline derivative, a dibenzoquinoline derivative, a pyridine derivative, a bipyridine derivative, and a pyrimidine derivative.

11. The light-receiving device of claim 1, wherein the third organic compound is a compound having a triazine ring.

12. The light-receiving device of claim 1, wherein the third organic compound is an organic compound represented by general formula (Ge-1): , where Ar1 to Ar3 independently represent one of hydrogen, an aryl group having 6 or more but less than 30 substituted or unsubstituted carbon atoms, and a heteroaryl group having 2 to 30 substituted or unsubstituted carbon atoms, and X1 and X2 independently represent one of carbon and nitrogen, wherein if one or both of X1 and X2 are carbon, the carbon is bonded to one of hydrogen, an aryl group having 6 or more but less than 30 substituted or unsubstituted carbon atoms, a heteroaryl group having 2 to 30 substituted or unsubstituted carbon atoms, an alkyl group having 1 to 20 substituted or unsubstituted carbon atoms, and a cycloalkyl group having 1 to 20 substituted or unsubstituted carbon atoms.

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