Light emitting device

Abstract

The present invention provides a high-definition light emitting device which emits blue light having a good blue index. The present invention provides a light emitting device which comprises a pixel electrode A, a pixel electrode B that is arranged adjacent to the pixel electrode A, a common electrode, an EL layer A that is sandwiched between the pixel electrode A and the common electrode, an EL layer B that is sandwiched between the pixel electrode B and the common electrode, and an insulating layer that is positioned between the common electrode and the EL layer A and between the common electrode and the EL layer B. The insulating layer has an opening A that is provided so as to overlap with the pixel electrode A, and an opening B that is provided so as to overlap with the pixel electrode B; the EL layer A comprises a light emitting layer A; the light emitting layer A comprises a light emitting substance A; the light emitting substance A emits blue light; the EL layer A is in contact with the pixel electrode A; the EL layer B is in contact with the pixel electrode B; the EL layer A is in contact with the common electrode through the opening A; and the EL layer B is in contact with the common electrode through the opening B.

Description

Light-emitting device

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

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

[0003] Since such light-emitting devices are self-luminous, when used as display pixels, they offer advantages such as higher visibility and no need for backlighting compared to liquid crystal displays, making them particularly suitable for flat panel displays. Another major advantage of displays using such light-emitting devices is that they can be fabricated to be thin and lightweight. Another feature is their extremely fast response time.

[0004] Furthermore, these light-emitting devices can have a continuous light-emitting layer formed two-dimensionally, enabling them to emit light in a planar form. This is a feature that is difficult to obtain with point light sources such as incandescent lamps or LEDs, or linear light sources such as fluorescent lamps, making them highly useful as planar light sources for lighting and other applications.

[0005] Although light emitting devices using such light emitting devices are suitable for a variety of electronic devices, research and development is ongoing to find light emitting devices with even better characteristics.

[0006] In order to obtain a light-emitting device with higher resolution using an organic EL device, research has been conducted into patterning of organic layers by photolithography using photoresist, etc., instead of vapor deposition using a metal mask. By using photolithography, a high-resolution light-emitting device with an EL layer spacing of several micrometers can be obtained (see, for example, Patent Document 1).

[0007] Special table 2018-521459 publication

[0008] In high-resolution light-emitting devices with an EL layer spacing of a few micrometers, the small pixel area tends to exacerbate the effects of the structure around the pixel electrode. For example, if leakage current causes light to be emitted unintentionally through a microcavity structure with a different optical path length around the pixel electrode, the emission spectrum becomes broader and color purity deteriorates. This is particularly noticeable in blue-emitting devices with a short optical path length in the original microcavity structure, resulting in a significant decrease in the blue index.

[0009] In view of the above, an object of one embodiment of the present invention is to provide a high-definition light-emitting device that emits blue light with a favorable blue index.

[0010] Therefore, one embodiment of the present invention provides a light-emitting device comprising: a pixel electrode A; a pixel electrode B disposed adjacent to the pixel electrode A; a common electrode; an EL layer A sandwiched between the pixel electrode A and the common electrode; an EL layer B sandwiched between the pixel electrode B and the common electrode; and an insulating layer positioned between the common electrode and the EL layer A and the EL layer B, wherein the insulating layer has an opening A overlapping the pixel electrode A and an opening B overlapping the pixel electrode B, the EL layer A has a light-emitting layer A, the light-emitting layer A has a light-emitting substance A, and the light-emitting substance A emits blue light, the EL layer A is in contact with the pixel electrode A, and the EL layer B is in contact with the pixel electrode B, the EL layer A is in contact with the common electrode via the opening A, and the EL layer B is in contact with the common electrode via the opening B.

[0011] Alternatively, another aspect of the present invention is a light-emitting device having the above-described configuration, in which an end of the pixel electrode A is covered by the EL layer A, and an end of the pixel electrode B is covered by the EL layer B.

[0012] Alternatively, another embodiment of the present invention is a light-emitting device having the above structure, in which an end of the EL layer A is covered with the insulating layer, and an end of the EL layer B is covered with the insulating layer.

[0013] Alternatively, another aspect of the present invention is a liquid crystal display device comprising: a pixel electrode A; a pixel electrode B disposed adjacent to the pixel electrode A; a common electrode; an EL layer A sandwiched between the pixel electrode A and the common electrode; an EL layer B sandwiched between the pixel electrode B and the common electrode; and an insulating layer positioned between the common electrode and the EL layer A and the EL layer B, wherein the insulating layer has an opening A provided so as to overlap the pixel electrode A and an opening B provided so as to overlap the pixel electrode B, and the EL layer A comprises a first EL layer A having a light-emitting layer A; and an insulating layer between the first EL layer A and the common electrode. a first EL layer B having a light-emitting layer B and a second EL layer B located between the first EL layer B and the common electrode, the light-emitting layer A having a light-emitting substance A, the light-emitting substance A emitting blue light, the first EL layer A being in contact with the pixel electrode A, the first EL layer B being in contact with the pixel electrode B, the second EL layer A being in contact with the first EL layer A through the opening A, and the second EL layer B being in contact with the first EL layer B through the opening B.

[0014] Alternatively, another embodiment of the present invention is a light-emitting device having the above structure, wherein the second EL layer is sandwiched between the insulating layer and the common electrode in a region that does not overlap with the pixel electrode A and the pixel electrode B.

[0015] Alternatively, another aspect of the present invention is a light-emitting device having the above-described configuration, in which an end of the pixel electrode A is covered by the first EL layer A, and an end of the pixel electrode B is covered by the first EL layer B.

[0016] Alternatively, another aspect of the present invention is a light-emitting device having the above-described structure, in which an end of the first EL layer A is covered by the insulating layer, and an end of the first EL layer B is covered by the insulating layer.

[0017] Another embodiment of the present invention is a light-emitting device having any of the above structures, in which the insulating layer contains an organic compound.

[0018] Another embodiment of the present invention is a light-emitting device having the above structure, wherein the opening A and the opening B have tapered side surfaces, and the tapered angle is less than 90°.

[0019] Another aspect of the present invention is a light-emitting device having the above-described structure, wherein the distance between the opposing ends of the pixel electrode A and the pixel electrode B is 0.5 μm or more and 5 μm or less.

[0020] Alternatively, in the above-described structure, the area of ​​the overlapping portion of the pixel electrode A, the EL layer A, and the common electrode is 5 μm ２ 15 μm or more ２ The light emitting device is as follows.

[0021] Another embodiment of the present invention is a light-emitting device having the above structure, in which the EL layer A has an emission spectrum from the opening A with a half width of 20 nm or less.

[0022] Another embodiment of the present invention is a light-emitting device having the above structure, wherein the light-emitting substance A has an emission spectrum with a half-width of 30 nm or less.

[0023] Another embodiment of the present invention is an electronic device including any of the above light-emitting devices, a sensor, an operation button, and a speaker or a microphone.

[0024] In this specification, the term "light-emitting device" includes an image display device using a light-emitting device. The term "light-emitting device" may also include a module in which a connector, such as an anisotropic conductive film or a TCP (Tape Carrier Package), is attached to a light-emitting device, a module in which a printed wiring board is provided at the end of a TCP, or a module in which an IC (integrated circuit) is directly mounted on a light-emitting device using a COG (Chip On Glass) method. Furthermore, lighting fixtures and the like may have a light-emitting device.

[0025] According to one embodiment of the present invention, a high-definition light-emitting device that emits blue light with a favorable blue index can be provided.

[0026] Note that the description of this effect does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. Note that effects other than these will become apparent from the description in the specification, drawings, claims, etc., and it is possible to extract other effects from the description in the specification, drawings, claims, etc.

[0027] FIGS. 1A, 1B, and 1C are schematic diagrams of light-emitting devices. FIGS. 2A and 2B are schematic diagrams of light-emitting devices. FIGS. 3A and 3B are diagrams illustrating an active matrix light-emitting device. FIGS. 4A and 4B are diagrams illustrating an active matrix light-emitting device. FIG. 5 is a diagram illustrating an active matrix light-emitting device. FIGS. 6A and 6B are diagrams illustrating a passive matrix light-emitting device. FIGS. 7A to 7D are diagrams illustrating a configuration example of a display device. FIGS. 8A to 8F are diagrams illustrating an example of a method for manufacturing a display device. FIGS. 9A to 9F are diagrams illustrating an example of a method for manufacturing a display device. FIGS. 10A and 10B are diagrams illustrating a lighting device. FIGS. 11A, 11B1, 11B2, and 11C are diagrams illustrating electronic devices. FIGS. 12A, 12B, and 12C are diagrams illustrating electronic devices. FIG. 13 is a diagram illustrating a lighting device. FIG. 14 is a diagram illustrating a lighting device. FIG. 15 is a diagram illustrating an in-vehicle display device and a lighting device. FIGS. 16A and 16B are diagrams illustrating electronic devices. FIGS. 17A, 17B, and 17C are diagrams illustrating electronic devices. FIG. 18 is a diagram illustrating an example configuration of a display device. FIG. 19 is a diagram illustrating the current efficiency-luminance characteristics of light-emitting device 1, light-emitting device 2, and comparative light-emitting device 1. FIG. 20 is a diagram illustrating the blue index-current density characteristics of light-emitting device 1, light-emitting device 2, and comparative light-emitting device 1. FIG. 21 is a diagram illustrating the emission spectra of light-emitting device 1, light-emitting device 2, and comparative light-emitting device 1. FIG. 22 shows the results of 2D spectroradiometer measurement in an example. FIG. 23 shows the results of 2D spectroradiometer measurement in an example. FIGS. 24A and 24B are diagrams illustrating EL intensity measured in 2D spectroradiometer measurement. FIGS. 25A and 25B are diagrams illustrating EL intensity measured in 2D spectroradiometer measurement. FIG. 26A is a diagram illustrating a light-emitting device in an example, and FIG. 26B is a diagram illustrating a cross-sectional STEM image illustrating the light-emitting mechanism and a 2D spectroradiometer image in an example.

[0028] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be readily understood by those skilled in the art that various changes in form and details can be made without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the embodiments shown below.

[0029] In this specification, etc., a device fabricated using a metal mask or an FMM (fine metal mask, high-resolution metal mask) may be referred to as a device with an MM (metal mask) structure. In addition, in this specification, etc., a device fabricated without using a metal mask or an FMM may be referred to as a device with an MML (metal maskless) structure.

[0030] 1A shows a diagram of a light-emitting device in a light-emitting device of one embodiment of the present invention. The light-emitting device has an EL layer 103 between a pair of electrodes (a pixel electrode (anode) 101 and a common electrode (cathode) 102). The EL layer 103 is in contact with the pixel electrode 101 and the common electrode 102, and emits light when a voltage is applied between the pixel electrode 101 and the common electrode 102 and a current flows between them. A light-emitting device of one embodiment of the present invention includes a plurality of such light-emitting devices.

[0031] 1B, the EL layer 103 may be composed of a first EL layer 103(1) including a light-emitting layer and a second EL layer 103(2) located between the first EL layer 103(1) and the common electrode 102 and in contact with the first EL layer 103(1) and the common electrode 102. As the second EL layer 103(2), a layer closer to the cathode than the light-emitting layer (a hole-blocking layer, an electron-transporting layer, or an electron-injecting layer) can be used, but an electron-injecting layer is preferred.

[0032] The EL layer 103 in each light-emitting device (EL layer 103(1) when EL layer 103(2) is provided) is separated from the adjacent light-emitting device in at least one direction. The EL layer 103 (EL layer 103(1)) may be provided so as to cover at least a pair of sides of the pixel electrode 101 as shown in FIGS. 1A and 1B, or may be provided so that the end of the EL layer 103 (EL layer 103(1)) is located inside the end of the pixel electrode 101 as shown in FIG. 1C.

[0033] At least one pair of opposing ends of the EL layer 103 (or the EL layer 103(1) when the EL layer 103(2) is provided) is covered with an insulating layer 125 containing an organic compound. An opening 128 overlapping the pixel electrode 101 is formed in the insulating layer 125.

[0034] The common electrode 102 is in contact with the EL layer 103 in the opening 128 (in the case where the EL layer 103(2) is provided, the common electrode 102 is in contact with the EL layer 103(2)).

[0035] Note that an insulating layer 126 may be provided between the EL layer 103 (EL layer 103(1)) and the insulating layer 125. The insulating layer 126 preferably contains an inorganic compound, more preferably aluminum oxide. In addition, it is preferable that the upper portion of the EL layer 103 (EL layer 103(1)) has a two-layer structure and the side portion has a single-layer structure, with the upper surface being thicker than the side surface.

[0036] 2B , the EL layer 103 preferably has a layered structure as shown in FIG. 2B , and includes at least the light-emitting layer 113. In addition, the EL layer 103 may include a hole-injection layer 111, a hole-transport layer 112, the light-emitting layer 113, an electron-transport layer 114, an electron-injection layer 115, and the like. Furthermore, the EL layer 103 may also include a hole-blocking layer, an electron-blocking layer, an exciton-blocking layer, an intermediate layer (charge-generating layer), and the like. Note that these are merely examples, and any layer other than the light-emitting layer 113 may or may not be provided, and a layer having multiple functions may be formed instead of a layer having multiple functions.

[0037] The light-emitting layer 113 contains a light-emitting substance. In this embodiment, the light-emitting substance is preferably a substance that emits blue light (having an emission peak wavelength of 440 nm to 480 nm, preferably 455 nm to 465 nm) because this is more effective. When a blue light-emitting substance is used as the light-emitting substance, it is preferable to use a substance whose half-width of the emission spectrum is 30 nm or less.

[0038] Fig. 2A shows a light-emitting device structure having a different configuration from that shown in Fig. 1. The light-emitting device shown in Fig. 2A does not have the insulating layer 125 of the light-emitting device shown in Fig. 1, but has an insulating layer 129 that covers the edge of the pixel electrode 101, and the EL layer 103 and the pixel electrode contact each other through an opening 128 provided in the insulating layer 129. In addition, the EL layer 103 is provided continuously, and the common electrode 102 contacts the upper surface of the EL layer 103 over an area wider than that of the pixel electrode.

[0039] 2A, especially when the hole injection layer located on the pixel electrode (anode) 101 side has high conductivity, current may flow not only between the opening in the insulating film and the common electrode overlapping it, but also between the opening and the common electrode located around it unintentionally. Light excited by this current (leakage current) emits light at a position different from the expected position, and the optical path length of some of the light from inside the light-emitting device to the outside of the device may deviate from the expected wavelength range.

[0040] Furthermore, the angle of the common electrode also changes depending on the position due to the unevenness of the insulating layer 129, which also makes it easier for such light to be emitted to the outside of the light-emitting device.

[0041] For these reasons, in a light-emitting device having the configuration shown in Figure 2A, light with a wavelength longer than the intended wavelength is mixed in during emission, resulting in a broadened emission spectrum and a shift of the emission peak to the longer wavelength side, resulting in a decrease in color purity, particularly a significant decrease in the blue index.

[0042] Here, the blue index (BI) is a value obtained by further dividing the current efficiency (cd / A) by the y chromaticity, and is one of the indices that represent the luminous characteristics of blue light emission. The smaller the y chromaticity, the higher the color purity of blue light emission tends to be. Blue light emission with high color purity can express a wide range of blue even with a small luminance component, and the use of blue light emission with high color purity reduces the required luminance to express blue, thereby achieving a reduction in power consumption. Therefore, the BI, which takes into account the y chromaticity, which is one index of blue purity, is preferably used as a means of expressing the efficiency of blue light emission. It can be said that a light-emitting device with a higher BI has better efficiency as a blue light-emitting device used in a display.

[0043] 1A to 1C , in the light-emitting device of one embodiment of the present invention, the common electrode 102 overlaps with the EL layer 103 (EL layer 103(1)) through the opening 128 in the insulating layer 126. Therefore, leakage current is unlikely to flow around the periphery of the common electrode 102, and light emissions with different wavelengths are unlikely to be mixed. Therefore, light emission with good color purity can be obtained, and a light-emitting device with a good blue index can be obtained. In such a blue light-emitting device, the half-width of the emission spectrum obtained from the opening 128 can be 20 nm or less.

[0044] Furthermore, since this phenomenon occurs in the periphery of the light-emitting device (around the area where the pixel electrode, the EL layer, and the common electrode are in contact with and overlap), it becomes more pronounced in a high-definition light-emitting device. Therefore, it can be said that the configuration of one embodiment of the present invention is particularly suitable for high-definition light-emitting devices. A high-definition light-emitting device corresponds to, for example, a light-emitting device in which adjacent pixel electrodes are arranged at a very narrow interval of 0.5 μm or more and 5 μm or less, preferably 0.5 μm or more and 1 μm or less. Alternatively, a light-emitting area (area of ​​the area where the pixel electrode, the EL layer, and the common electrode are in contact with and overlap with each other (overlapping without an insulating layer sandwiched between them)) of one light-emitting device is 5 μm or less. ２ 15 μm or more ２ Less than 5 μm, preferably ２ 10 μm or more ２ The following light emitting devices are applicable.

[0045] Note that the light-emitting device of one embodiment of the present invention can also reduce leakage current (also referred to as lateral leakage current) that may occur between adjacent light-emitting devices. For example, when a hole-injection layer is shared between adjacent subpixels, lateral leakage current may occur due to the hole-injection layer. On the other hand, in the light-emitting device of one embodiment of the present invention, the EL layer 103 (EL layer 103(1)) is separated from the adjacent light-emitting device in at least one direction, so that lateral leakage current is substantially eliminated or can be made extremely small.

[0046] Furthermore, the light-emitting device of one embodiment of the present invention has a wider margin for alignment accuracy between different patternings and less variation than the light-emitting device illustrated in FIGS.

[0047] The structure of this embodiment mode can be used in appropriate combination with other structures.

[0048] Next, other examples of the structure and materials of the light-emitting device of one embodiment of the present invention will be described. As described above, the light-emitting device of one embodiment of the present invention includes the EL layer 103 composed of a plurality of layers between a pair of electrodes, that is, the pixel electrode (anode) 101 and the common electrode (cathode) 102. The EL layer 103 preferably includes the light-emitting layer 113 containing a light-emitting material and at least a first organic compound (and a second organic compound), and a hole-blocking layer containing a third organic compound.

[0049] The anode is preferably formed using a metal, alloy, conductive compound, or mixture thereof having a large work function (specifically, 4.0 eV or more). Specific examples include indium oxide-tin oxide (ITO), indium oxide-tin oxide containing silicon or silicon oxide, indium oxide-zinc oxide, and indium oxide containing tungsten oxide and zinc oxide (IWZO). These conductive metal oxide films are usually formed by sputtering, but may also be prepared by applying a sol-gel method. As an example of a preparation method, indium oxide-zinc oxide can be formed by sputtering using a target in which 1 to 20 wt % of zinc oxide is added to indium oxide. Indium oxide containing tungsten oxide and zinc oxide (IWZO) can also be formed by sputtering using a target containing 0.5 to 5 wt % tungsten oxide and 0.1 to 1 wt % zinc oxide relative to indium oxide. Other materials that can be used for the anode include, for example, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), and nitrides of metal materials (e.g., titanium nitride). Alternatively, graphene can be used for the anode. Note that using a composite material (described below) for the layer in contact with the anode in the EL layer 103 allows the electrode material to be selected regardless of the work function.

[0050] The EL layer 103 preferably has a stacked layer structure, but the stacked layer structure is not particularly limited, and various layer structures such as a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, a carrier blocking layer (hole blocking layer, electron blocking layer), an exciton blocking layer, and a charge generation layer can be applied. Note that any of the layers does not necessarily have to be provided. In this embodiment, a structure including a hole injection layer 111, a hole transport layer 112, a light-emitting layer 113, a hole blocking layer, an electron transport layer 114, and an electron injection layer 115 as shown in FIG. 2B will be specifically described below.

[0051] The hole-injection layer 111 is a layer containing a substance having acceptor properties. As the substance having acceptor properties, either an organic compound or an inorganic compound can be used.

[0052] As the substance having acceptor properties, a compound having an electron-withdrawing group (a halogen group or a cyano group) can be used, and 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F ４ -TCNQ), chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile, etc. In particular, compounds in which an electron-withdrawing group is bonded to a fused aromatic ring having a plurality of heteroatoms, such as HAT-CN, are thermally stable and preferred. Furthermore, [3]radialene derivatives having an electron-withdrawing group (especially a halogen group such as a fluoro group or a cyano group) are preferred because of their extremely high electron-accepting properties. Specific examples include α,α',α''-1,2,3-cyclopropanetriylidenetris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidenetris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], and α,α',α''-1,2,3-cyclopropanetriylidenetris[2,3,4,5,6-pentafluorobenzeneacetonitrile]. In addition to the organic compounds mentioned above, other materials that can be used as acceptors include molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, manganese oxide, and the like. Other examples include phthalocyanine (abbreviated as H ２The hole injection layer 111 can also be formed from a phthalocyanine complex compound such as copper phthalocyanine (CuPc) or copper phthalocyanine (CuPc), an aromatic amine compound such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB) or N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviation: DNTPD), or a polymer such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (PEDOT / PSS). A substance having acceptor properties can extract electrons from an adjacent hole transport layer (or hole transport material) when an electric field is applied.

[0053] Among substances having acceptor properties, organic compounds having acceptor properties are easy to use because they can be easily vapor-deposited and formed into a film.

[0054] Furthermore, a composite material in which the above-described acceptor substance is contained in a material having a hole-transporting property can also be used for the hole-injection layer 111. Note that by using a composite material in which the acceptor substance is contained in a material having a hole-transporting property, a material for forming an electrode can be selected regardless of the work function. In other words, not only a material with a high work function but also a material with a low work function can be used for the anode.

[0055] As the material having a hole transport property used for the composite material, various organic compounds such as aromatic amine compounds, carbazole derivatives, aromatic hydrocarbons, and polymer compounds (oligomers, dendrimers, polymers, etc.) can be used. −６ cm ２ A substance having a hole mobility of 1 / Vs or more is preferred. Specific examples of organic compounds that can be used as a material having a hole transport property in a composite material are listed below.

[0056] Examples of aromatic amine compounds that can be used in the composite material include N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviation: DNTPD), and 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B). Specific examples of the carbazole derivative include 3-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole, and Carbazolyl (abbreviation: PCzPCN1), 4,4'-di(N-carbazolyl)biphenyl (abbreviation: CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviation: TCPB), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene, etc. can be used.Examples of aromatic hydrocarbons include 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 2-tert-butyl-9,10-di(1-naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 2-tert-butyl-9,10-bis(4-phenylphenyl)anthracene (abbreviation: t-BuDBA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 9,10-diphenylanthracene (abbreviation: DPAnth), 2-tert-butylanthracene (abbreviation: t-BuAnth), 9,10-bis(4-methyl-1-naphthyl)anthracene (abbreviation: DMNA), 2-tert- Examples of suitable anthracene include butyl-9,10-bis[2-(1-naphthyl)phenyl]anthracene, 9,10-bis[2-(1-naphthyl)phenyl]anthracene, 2,3,6,7-tetramethyl-9,10-di(1-naphthyl)anthracene, 2,3,6,7-tetramethyl-9,10-di(2-naphthyl)anthracene, 9,9'-bianthryl, 10,10'-diphenyl-9,9'-bianthryl, 10,10'-bis(2-phenylphenyl)-9,9'-bianthryl, 10,10'-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9'-bianthryl, anthracene, tetracene, rubrene, perylene, and 2,5,8,11-tetra(tert-butyl)perylene. In addition, pentacene, coronene, and the like can also be used. The aromatic hydrocarbon having a vinyl group may also have a vinyl skeleton. Examples of the aromatic hydrocarbon having a vinyl group include 4,4′-bis(2,2-diphenylvinyl)biphenyl (abbreviation: DPVBi) and 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviation: DPVPA). Note that the organic compound of one embodiment of the present invention can also be used.

[0057] Alternatively, polymer compounds such as poly(N-vinylcarbazole) (abbreviation: PVK) or poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD) can also be used.

[0058] The hole-transporting material used in the composite material preferably has a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, or an anthracene skeleton. In particular, the organic compound may be an aromatic amine having a substituent containing a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine having a naphthalene ring, or an aromatic monoamine in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group. It is preferable that the organic compound is a substance having an N,N-bis(4-biphenyl)amino group, since this allows the fabrication of a light-emitting device with a long lifetime. Specific examples of such organic compounds include N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4′-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine), and 4,4′-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine. 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-6-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-8 ... lan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: : BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-Diphenyl-4"-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4"-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4"-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4"-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-diphenyl-4"-(5;2'-binaphthyl-2-yl)triphenylamine 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazol-9-yl)phenyl]tris(1,1'-biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazol-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenyl amine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9′-spirobi[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N-bis(4-biphenylyl)-9,9′-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(1,1′-biphenyl-4-yl)-9,9′-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(1,1′-biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(4-biphenyl)-N-(dibenzofuran-4-yl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4 -phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]spiro-9,9'-bifluoren-2-amine (abbreviation: PCBASF), N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]spiro-9,9'-bifluoren-2-amine (abbreviation: PCBASF), N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF), N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-1-amine, and the like can be mentioned.

[0059] Note that the material having hole-transporting properties used in the composite material is more preferably a substance having a relatively deep HOMO level of -5.7 eV or more and -5.4 eV or less. When the material having hole-transporting properties used in the composite material has a relatively deep HOMO level, injection of holes into the hole-transport layer 112 becomes easy, and a light-emitting device with a long lifetime can be easily obtained. Furthermore, when the material having hole-transporting properties used in the composite material is a substance having a relatively deep HOMO level, induction of holes can be appropriately suppressed, and a light-emitting device with a long lifetime can be obtained.

[0060] The refractive index of the layer can be reduced by further mixing an alkali metal or alkaline earth metal fluoride with the composite material (preferably with a fluorine atom ratio of 20% or more in the layer), which also allows a layer with a low refractive index to be formed inside the EL layer 103, thereby improving the external quantum efficiency of the light-emitting device.

[0061] By forming the hole injection layer 111, the hole injection property becomes good, and a light emitting device with a low driving voltage can be obtained.

[0062] The hole transport layer 112 is formed by containing a material having a hole transport property. −６ cm ２ It is preferable that the material has a hole mobility of 1.0 V or more.

[0063] Examples of the material having a hole transport property include 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1′-biphenyl]-4,4′-diamine (abbreviation: TPD), 4,4′-bis[N-(spiro-9,9′-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), and 4-phenyl-3′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP). 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), compounds having an aromatic amine skeleton such as 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]spiro-9,9'-bifluoren-2-amine (abbreviation: PCBASF); 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N-carbazolyl)biphenyl; carbazole (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviation: BisBPCz), 9,9'-bis(1,1'-biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviation: BismBPCz), 9-(1,1'-biphenyl-3-yl)-9'-(1,1'-biphenyl-4-yl)-9H,9'H-3,3'-bicarbazole (abbreviation: mBPCCBP), 9-(2-naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: βNCCP), 9-(3-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCmBP), 9-(4-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCBP), 9,9'-di-2-naphthyl-3,3'-9H,9'H-bicarbazole (abbreviation: :BisβNCz), 9-(2-naphthyl)-9'-[1,1':4',1"-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-5'-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':4',1"- terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, 9-phenyl-9'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviation: PCCzTp), 9,9'-bis(triphenylene-2 compounds having a carbazole skeleton such as 9-(4-biphenyl)-9'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(triphenylen-2-yl)-9'-[1,1':3',1"-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,Examples of suitable compounds include compounds having a thiophene skeleton, such as 8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III) and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), and compounds having a furan skeleton, such as 4,4′,4″-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II). Among the compounds listed above, compounds having an aromatic amine skeleton or a carbazole skeleton are preferred because they have good reliability, high hole transport properties, and contribute to reducing driving voltage. Note that the substances listed as the materials having hole transport properties used in the composite material of the hole injection layer 111 can also be suitably used as materials for forming the hole transport layer 112.

[0064] The light-emitting layer 113 preferably contains a light-emitting substance and a first organic compound. It may further contain a second organic compound. The light-emitting layer 113 may also contain other materials. It may also be a stack of two layers with different compositions. It is preferable that the first organic compound is an organic compound having an electron-transporting property, and the second organic compound is an organic compound having a hole-transporting property.

[0065] The light-emitting substance may be a fluorescent substance, a phosphorescent substance, or a substance that exhibits thermally activated delayed fluorescence (TADF).

[0066] Examples of materials that can be used as the fluorescent substance in the light-emitting layer 113 include the following: In addition, fluorescent substances other than these can also be used.

[0067] 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2,2'-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl-9-anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine )phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-( 10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis[N,N',N'-triphenyl-1,4-phenylenediamine] (abbreviation: DPABPA), N,9 -diphenyl-N-[4-(9,10-diphenyl-2-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: 2PAPPA), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), N,N,N',N',N'',N'',N''',N'''-octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), Coumarin 30, N-(9,10-diphenyl-2-anthryl)-N,9-Diphenyl-9H-carbazole-3-amine (abbreviation: 2PCAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPA BPhA), 9,10-bis(1,1'-biphenyl-2-yl)-N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracen-9-amine (abbreviation: DPhAPhA), Coumarin 545T, N,N'-diphenylquinacridone (abbreviation: DPQd), rubrene, 5,12-bis(1,1'-biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6 -methyl-4H-pyran-4-ylidene)propanedinitrile (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM2), N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine amine (abbreviation: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2,6-bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJ™), N,N'-diphenyl-N,N'-(1,6-pyren-diyl)bis[(6-phenylbenzo[b ]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10PCA2Nbf(IV)-02), and 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02). In particular, condensed aromatic diamine compounds typified by pyrene diamine compounds such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03 are preferred because they have high hole-trapping properties and excellent luminous efficiency or reliability. ,

[0068] When a phosphorescent material is used as the light-emitting material in the light-emitting layer 113, examples of materials that can be used include the following.

[0069] (Diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(III) (abbreviation: [Ir(5mdppm) ２ (dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(5mdppm) ２ (dpm)]), bis[4,6-di(naphthalen-1-yl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(dpm) ２organometallic iridium complexes having a pyrimidine skeleton, such as (acetylacetonato)bis(2,3,5-triphenylpyrazinato)iridium(III) (abbreviation: [Ir(tppr) ２ (acac)]), bis(2,3,5-triphenylpyrazinato)(dipivaloylmethanato)iridium(III) (abbreviation: [Ir(tppr) ２ (dpm)]), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq) ２ organometallic iridium complexes having a pyrazine skeleton, such as tris(1-phenylisoquinolinato-N,C(acac)]); ２’ ) Iridium(III) (abbreviation: [Ir(piq) ３ ]), bis(1-phenylisoquinolinato-N,C ２’ ) iridium(III) acetylacetonate (abbreviation: [Ir(piq) ２ (acac)]), (3,7-diethyl-4,6-nonanedionato-κO4,κO6)bis[2,4-dimethyl-6-[7-(1-methylethyl)-1-isoquinolinyl-κN]phenyl-κC]iridium(III), (3,7-diethyl-4,6-nonanedionato-κO4,κO6)bis[2,4-dimethyl-6-[5-(1-methylethyl)-2-quinolinyl-κN]phenyl-κC]iridium(III). In addition to organometallic iridium complexes having a pyridine skeleton such as [ru-κC]iridium(III), platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrinplatinum(II) (abbreviation: PtOEP), tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: [Eu(DBM) ３ (Phen)]), tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: [Eu(TTA) ３Examples of suitable iridium complexes include rare earth metal complexes such as iridium fluoride (Phen). These have emission peaks in the wavelength range of 600 nm to 700 nm. Organometallic iridium complexes having a pyrazine skeleton can emit red light with good chromaticity. Other known substances that exhibit red phosphorescence can also be used.

[0070] Tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN]phenyl-κC}iridium(III) (abbreviation: [Ir(mpptz-dmp) ３ ]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Mptz) ３ organometallic iridium complexes having a 4H-triazole skeleton, such as tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(Mptz1-mp) ３ ]), tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Prptz1-Me) ３ organometallic iridium complexes having a 1H-triazole skeleton, such as fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpmi) ３ ]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me) ３ organometallic iridium complexes having an imidazole skeleton, such as tris(2-[1-{2,6-bis(1-methylethyl)phenyl}-1H-imidazol-2-yl-κN]-4-cyanophenyl-κC) (abbreviation: CNImIr), tris[(6-tert-butyl-3-phenyl-2H-imidazo[4,5-b]pyrazin-1-yl-κC)phenyl-κC]iridium(III) (abbreviation: [Ir(cb) ３organometallic complexes having a benzimidazolidene skeleton, such as bis[2-(4',6'-difluorophenyl)pyridinato-N,C ２’ ]iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridinato-N,C ２’ ]iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinato-N,C ２’} Iridium(III) picolinate (abbreviation: [Ir(CF ３ ppy) ２ (pic)]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C ２’ ] Organometallic iridium complexes having a phenylpyridine derivative having an electron-withdrawing group as a ligand, such as iridium(III) acetylacetonate (abbreviation: FIracac), are examples of such compounds that exhibit blue phosphorescence and have an emission peak in the wavelength range of 440 nm to 520 nm.

[0071] Also, tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm) ３ ]), tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm) ３ ]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm) ２ (acac)]), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm) ２ (acac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm) ２ (acac)]), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(mpmppm) ２(acac)]), (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm) ２ organometallic iridium complexes having a pyrimidine skeleton, such as (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-Me) ２ (acac)]), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-iPr) ２ organometallic iridium complexes having a pyrazine skeleton, such as tris(2-phenylpyridinato-N,C(acac)]); ２’ ) Iridium(III) (abbreviation: [Ir(ppy) ３ ]), bis(2-phenylpyridinato-N,C ２’ ) Iridium(III) acetylacetonate (abbreviation: [Ir(ppy) ２ (acac)]), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: [Ir(bzq) ２ (acac)]), tris(benzo[h]quinolinato)iridium(III) (abbreviation: [Ir(bzq) ３ ]), tris(2-phenylquinolinato-N,C ２’ ) Iridium(III) (abbreviation: [Ir(pq) ３ ]), bis(2-phenylquinolinato-N,C ２’ ) iridium(III) acetylacetonate (abbreviation: [Ir(pq) ２ (acac)]), [2-d3-methyl-8-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(5mppy-d3) ２(mbfpypy-d3)), [2-(methyl-d3)-8-[4-(1-methylethyl-1-d)-2-pyridinyl-κN]benzofuro[2,3-b]pyridin-7-yl-κC]bis[5-(methyl-d3)-2-[5-(methyl-d3)-2-pyridinyl-κN]phenyl-κC]iridium(III) (abbreviation: Ir(5mtpy-d6) ２ (mbfpypy-iPr-d4)), [2-d3-methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy) ２ (mbfppypy-d3)), [2-(4-d3-methyl-5-phenyl-2-pyridinyl-κN2)phenyl-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) (abbreviation: [Ir(5mppy-d3)2(mdppy-d3)]), [2-methyl-(2-pyridinyl-κN)benzofuro[ [2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy)2(mbfpypy)]), [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy) ２ In addition to organometallic iridium complexes having a pyridine skeleton, such as tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: [Tb(acac) ３ These compounds mainly exhibit green phosphorescence, with an emission peak in the wavelength range of 500 nm to 600 nm. Organometallic iridium complexes having a pyrimidine skeleton are particularly preferred because they are remarkably excellent in reliability and luminous efficiency.

[0072] Examples of TADF materials that can be used include fullerene and its derivatives, acridine and its derivatives, and eosin derivatives. Other examples include metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd). Examples of metal-containing porphyrins include protoporphyrin-tin fluoride complexes (SnF) represented by the following structural formula: ２ (Proto IX)), mesoporphyrin-tin fluoride complex (SnF ２ (Meso IX)), hematoporphyrin-tin fluoride complex (SnF ２ (Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (SnF ２ (Copro III-4Me)), octaethylporphyrin-tin fluoride complex (SnF ２ (OEP)), etioporphyrin-tin fluoride complex (SnF ２ (Etio I)), octaethylporphyrin-platinum chloride complex (PtCl ２ OEP) and the like.

[0073]

[0074] Further, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9′-phenyl-9H,9′H-3,3′-bicarbazole (abbreviation: PCCzTzn), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), and Heterocyclic compounds having one or both of a π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring, such as 3-[4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviation: DMAC-DPS), and 10-phenyl-10H,10′H-spiro[acridine-9,9′-anthracene]-10′-one (abbreviation: ACRSA), can also be used. The heterocyclic compound has a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring, and therefore has high electron transport and hole transport properties, and is therefore preferred. Among the skeletons having a π-electron-deficient heteroaromatic ring, pyridine skeleton, diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), and triazine skeleton are preferred because they are stable and reliable. In particular, benzofuropyrimidine skeleton, benzothienopyrimidine skeleton, benzofuropyrazine skeleton, and benzothienopyrazine skeleton are preferred because they have high acceptor properties and good reliability. Furthermore, among the skeletons having a π-electron-rich heteroaromatic ring, acridine skeleton, phenoxazine skeleton, phenothiazine skeleton, furan skeleton, thiophene skeleton, and pyrrole skeleton are preferred because they are stable and reliable.The furan skeleton is preferably a dibenzofuran skeleton, and the thiophene skeleton is preferably a dibenzothiophene skeleton. The pyrrole skeleton is particularly preferably an indole skeleton, a carbazole skeleton, an indolocarbazole skeleton, a bicarbazole skeleton, or a 3-(9-phenyl-9H-carbazol-3-yl)-9H-carbazole skeleton. A substance in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded is particularly preferred because the electron-donating property of the π-electron-rich heteroaromatic ring and the electron-accepting property of the π-electron-deficient heteroaromatic ring are both enhanced, reducing the energy difference between the S1 level and the T1 level, thereby enabling efficient thermally activated delayed fluorescence. Instead of the π-electron-deficient heteroaromatic ring, an aromatic ring bonded to an electron-withdrawing group such as a cyano group may be used. The π-electron-rich skeleton may be, for example, an aromatic amine skeleton or a phenazine skeleton. Examples of usable π-electron-deficient skeletons include a xanthene skeleton, a thioxanthene dioxide skeleton, an oxadiazole skeleton, a triazole skeleton, an imidazole skeleton, an anthraquinone skeleton, a boron-containing skeleton such as phenylborane or boranthrene, an aromatic ring or heteroaromatic ring having a nitrile group or a cyano group such as benzonitrile or cyanobenzene, a carbonyl skeleton such as benzophenone, a phosphine oxide skeleton, a sulfone skeleton, etc. In this way, a π-electron-deficient skeleton and a π-electron-rich skeleton can be used in place of at least one of a π-electron-deficient heteroaromatic ring and a π-electron-rich heteroaromatic ring.

[0075]

[0076] Alternatively, a TADF material may be used, which is capable of extremely fast and reversible intersystem crossing and emits light according to a thermal equilibrium model between a singlet excited state and a triplet excited state. Such a TADF material has an extremely short emission lifetime (excitation lifetime) for a TADF material, and can suppress a decrease in efficiency in the high-brightness region of a light-emitting device. Specifically, a material with the molecular structure shown below may be used.

[0077]

[0078] The TADF material is a material that has a small difference between the S1 level and the T1 level and has the function of converting triplet excitation energy to singlet excitation energy by reverse intersystem crossing. Therefore, triplet excitation energy can be upconverted to singlet excitation energy (reverse intersystem crossing) with a small amount of thermal energy, and a singlet excited state can be efficiently generated. Furthermore, triplet excitation energy can be converted into luminescence.

[0079] Furthermore, an exciplex (also called an exciplex) that forms an excited state with two types of substances has an extremely small difference between the S1 level and the T1 level, and functions as a TADF material that can convert triplet excitation energy into singlet excitation energy.

[0080] The T1 level can be determined by using a phosphorescence spectrum observed at low temperatures (e.g., 77 K to 10 K). When a tangent line is drawn at the base of the fluorescence spectrum on the short wavelength side of the TADF material, and the energy of the wavelength of the extrapolated line is defined as the S1 level, and when a tangent line is drawn at the base of the phosphorescence spectrum on the short wavelength side of the TADF material, and the energy of the wavelength of the extrapolated line is defined as the T1 level, the difference between S1 and T1 is preferably 0.3 eV or less, and more preferably 0.2 eV or less.

[0081] When a TADF material is used as a light-emitting material, the S1 level of the host material is preferably higher than the S1 level of the TADF material, and the T1 level of the host material is preferably higher than the T1 level of the TADF material.

[0082] Note that in the light-emitting device of one embodiment of the present invention, significant effects can be obtained when the light-emitting substance is a substance that emits blue light. Therefore, one embodiment of the present invention is preferably applied to a light-emitting device that includes a light-emitting substance that emits blue light.

[0083] Examples of electron transport materials used as the host material include bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq ２), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq), bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO), bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ), or other metal complexes; and organic compounds having a π-electron-deficient heteroaromatic ring can be used. Examples of organic compounds having a π-electron-deficient heteroaromatic ring include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 2,2′,2″-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), etc. and organic compounds containing heteroaromatic rings, such as 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCz BPDBq), 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 2,6-bis(4-naphthalen-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 6-(1,1′-biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(1,1'-biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 7-[4-(9-phenyl-9H-carbazol-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: PC-cgDBCzQz), 11-[(3'-dibenzothiophen-4-yl)biphenyl-3-yl]phenanthroline 11-[(3'-dibenzothiophen-4-yl)biphenyl-4-yl]phenanthro[9',10':4,5]furo[2,3-b]pyrazine (abbreviation: 11mDBtBPPnfpr), 11-[(3'-dibenzothiophen-4-yl)biphenyl-4-yl]phenanthro[9',10':4,5]furo[2,3-b]pyrazine, 11-[(3'-(9H-carbazol-9-yl)biphenyl-3-yl]phenanthro[9',10':4,5]furo[2,3-b]pyrazine, 12-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)phenanthro[9',10':4,5]furo[2,3-b]pyrazine (abbreviation 9-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9pmPCBPNfpr), 9-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9PCCzNfpr), 10-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 10PCCzNf pr), 9-[3'-(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mBnfBPNfpr), 9-{3-[6-(9,9-dimethylfluoren-2-yl)dibenzothiophen-4-yl]phenyl}naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mFDBtPNfpr), 9-[3'-(6-phenyldibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr-02), 9-[3-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)phenyl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mPCCzPNfpr), 9-{3'-[2,8-diphenyldibenzothiophen-4-yl]biphenyl-3-yl}naphtho[1',2':4,5]furo[2,3-b]pyrazine, 11-{3'-[2,8-diphenyldibenzothiophen-4-yl]biphenyl-3-yl}phenanthro[9',10':4,5 ]furo[2,3-b]pyrazine and other organic compounds containing heteroaromatic rings with a diazine skeleton; 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB) and other organic compounds containing heteroaromatic rings with a pyridine skeleton; 2-[3′-(9,9-dimethyl-9H-fluoren-2-yl)-1,1′-biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 2-[(1, 1'-biphenyl)-4-yl]-4-phenyl-6-[9,9'-spirobi(9H-fluoren)-2-yl]-1,3,5-triazine (abbreviation: BP-SFTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn-02), 5 -[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-[3'-(triphenylen-2-yl)-1,1'-biphenyl-3-yl]-4,6-diphenyl'1,3,5-triazine (abbreviation: mTpBPTzn), 9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzothiophenyl]-2-phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-[1,Examples of suitable organic compounds include organic compounds containing a heteroaromatic ring having a triazine skeleton, such as [1'-biphenyl]-3-yl-4-phenyl-6-(8-[1,1':4',1''-terphenyl]-4-yl-1-dibenzofuranyl)-1,3,5-triazine (abbreviation: mBP-TPDBfTzn). Among the above, organic compounds containing a heteroaromatic ring having a diazine skeleton, organic compounds containing a heteroaromatic ring having a pyridine skeleton, and organic compounds containing a heteroaromatic ring having a triazine skeleton are preferred due to their high reliability. In particular, organic compounds containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing a heteroaromatic ring having a triazine skeleton have high electron transport properties and contribute to reduced driving voltage.

[0084] The hole transport material used as the host material can be an organic compound having an amine skeleton or a π-electron-rich heteroaromatic ring. Examples of the organic compound having an amine skeleton or a π-electron-rich heteroaromatic ring include 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1′-biphenyl]-4,4′-diamine (abbreviation: TPD), 4,4′-bis[N-(spiro-9,9′-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), and 4-phenyl-4′-(9-phenylfluoren-9-yl). Triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine aromatic amines such as 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), and N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]spiro-9,9'-bifluoren-2-amine (abbreviation: PCBASF). compounds having an amine skeleton, 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4′-di(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 3,3′-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-bis(9,9-dimethyl-9H-fluoren-2-yl)amine (abbreviation: PCBFF), N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-4-amine, N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-(9,9-dimethyl-9H-fluoren-2-yl)-9,9-dimethyl-9H-fluoren-4-amine, N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-diphenyl-9H-fluoren- N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-diphenyl-9H-fluoren-4-amine, N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi(9H-fluorene)-2-amine (abbreviation: PCBBiSF), N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi(9H-fluorene)-2-amine (abbreviation: PCBBiSF), N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-diphenyl-9H-fluoren-4-amine N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-(1,1':3',1"-terphenyl-4-yl)-9,9-dimethyl-9H-fluoren-2-amine, N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-(1,1':4',1"-terphenyl-4-yl)-9,9-dimethyl-9H-fluoren-2-amine, N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-(1,1':4',1"-terphenyl-4-yl)-9,9-dimethyl-9H-fluoren-2-amine, N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-(1,1':4',1"-terphenyl-4-yl)-9,9-dimethyl-9H-fluoren-2-amine compounds having a carbazole skeleton such as N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-(1,1':3',1''-terphenyl-4-yl)-9,9-dimethyl-9H-fluoren-4-amine and N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-(1,1':4',1''-terphenyl-4-yl)-9,9-dimethyl-9H-fluoren-4-amine; 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II);Examples of suitable compounds include compounds having a thiophene skeleton, such as 8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III) and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), and compounds having a furan skeleton, such as 4,4′,4″-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II). Among the compounds listed above, compounds having an aromatic amine skeleton or a carbazole skeleton are preferred because they have good reliability, high hole transport properties, and contribute to reducing driving voltage. In addition, the organic compounds listed as examples of the material having hole transport properties in the hole transport layer 112 can also be used as the hole transport material of the host.

[0085] By mixing an electron transport material and a hole transport material, the transport property of the light-emitting layer 113 can be easily adjusted, and the recombination region can be easily controlled. In addition, a TADF material can also be used as an electron transport material or a hole transport material.

[0086] The TADF materials that can be used as the host material can be the same as those listed above. When a TADF material is used as a host material, triplet excitation energy generated in the TADF material is converted into singlet excitation energy by reverse intersystem crossing, and the energy is further transferred to a light-emitting substance, thereby improving the luminous efficiency of the light-emitting device. In this case, the TADF material functions as an energy donor, and the light-emitting substance functions as an energy acceptor.

[0087] This is very effective when the luminescent material is a fluorescent luminescent material. Furthermore, in this case, in order to obtain high luminous efficiency, it is preferable that the S1 level of the TADF material is higher than the S1 level of the fluorescent luminescent material. Furthermore, it is preferable that the T1 level of the TADF material is higher than the S1 level of the fluorescent luminescent material. Therefore, it is preferable that the T1 level of the TADF material is higher than the T1 level of the fluorescent luminescent material.

[0088] It is also preferable to use a TADF material that emits light that overlaps with the wavelength of the lowest-energy absorption band of the fluorescent material, since this allows for smooth transfer of excitation energy from the TADF material to the fluorescent material, resulting in efficient light emission.

[0089] Furthermore, in order to efficiently generate singlet excitation energy from triplet excitation energy through reverse intersystem crossing, it is preferable that carrier recombination occurs in the TADF material. It is also preferable that the triplet excitation energy generated in the TADF material does not transfer to the triplet excitation energy of the fluorescent material. To this end, it is preferable that the fluorescent material has a protecting group around the luminophore (the skeleton responsible for light emission) possessed by the fluorescent material. The protecting group is preferably a substituent without a π bond, and is preferably a saturated hydrocarbon. Specific examples include alkyl groups having 3 to 10 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 10 carbon atoms, and trialkylsilyl groups having 3 to 10 carbon atoms. It is even more preferable that the protecting group has multiple protecting groups. Substituents without a π bond have poor carrier transport function, so the distance between the TADF material and the luminophore of the fluorescent material can be increased without significantly affecting carrier transport or carrier recombination. Here, the luminophore refers to the atomic group (skeleton) responsible for light emission in the fluorescent material. The luminophore preferably has a skeleton having a π bond, preferably contains an aromatic ring, and preferably has a fused aromatic ring or a fused heteroaromatic ring. Examples of the fused aromatic ring or the fused heteroaromatic ring include a phenanthrene skeleton, a stilbene skeleton, an acridone skeleton, a phenoxazine skeleton, and a phenothiazine skeleton. In particular, fluorescent substances having a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, a chrysene skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, or a naphthobisbenzofuran skeleton are preferred because of their high fluorescence quantum yield.

[0090] When a fluorescent light-emitting substance is used as the light-emitting substance, a material having an anthracene skeleton is suitable as the host material. Using a substance having an anthracene skeleton as the host material for a fluorescent light-emitting substance makes it possible to realize an emitting layer with both excellent luminous efficiency and durability. As a substance having an anthracene skeleton to be used as the host material, a substance having a diphenylanthracene skeleton, particularly a 9,10-diphenylanthracene skeleton, is preferred because it is chemically stable. Furthermore, a host material having a carbazole skeleton is preferred because it enhances hole injection and transport properties. However, a host material containing a benzocarbazole skeleton in which a benzene ring is further condensed to carbazole is more preferred because its HOMO is shallower by about 0.1 eV than that of carbazole, making it easier for holes to enter. In particular, a host material containing a dibenzocarbazole skeleton is preferred because its HOMO is shallower by about 0.1 eV than that of carbazole, making it easier for holes to enter, and it also has excellent hole transport properties and high heat resistance. Therefore, a more preferable host material is a substance having both a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzocarbazole skeleton or a dibenzocarbazole skeleton). Note that, in view of the hole injection / transport property, a benzofluorene skeleton or a dibenzofluorene skeleton may be used instead of the carbazole skeleton.Examples of such substances include 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA), 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 6-[3-(9,10-diphenyl-2 -anthryl)phenyl]-benzo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10-{4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4'-yl}anthracene (abbreviation: FLPPA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviation: α,βADN), 2-(10-phenylanthracen-9-yl)dibenzofuran, 2-(10-phenyl- 9-anthracenyl)-benzo[b]naphtho[2,3-d]furan (abbreviation: Bnf(II)PhA), 9-(2-naphthyl)-10-[3-(2-naphthyl)phenyl]anthracene (abbreviation: βN-mβNPAnth), 1-[4-(10-[,1,1′-biphenyl]-4-yl-9-anthracenyl)phenyl]-2-ethyl-1H-benzimidazole (abbreviation: EtBImPBPhA), 2,9-di(1-naphthyl)-10-phenylanthracene (abbreviation: 2αN-αNPhA), 9-(1-naphthyl)-10-[3-(1-naphthyl)phenyl]anthracene (abbreviation: βN-mβNPAnth),

[0033] 9-(2-naphthyl)-10-[3-(1-naphthyl)phenyl]anthracene (abbreviation: αN-mαNPAnth), 9-(1-naphthyl)-10-[4-(1-naphthyl)phenyl]anthracene (abbreviation: αN-αNPAnth), 9-(2-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: βN-βNPAnth), 2-(1-naphthyl)-9-(2-naphthyl)-10-phenylanthracene (abbreviation: 2αN-βNPh), and the like.In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA are preferable choices because they exhibit very good properties.

[0091] A phosphorescent material can be used as part of the mixed material. The phosphorescent material can be used as an energy donor that provides excitation energy to a fluorescent material when the fluorescent material is used as a light-emitting material.

[0092] The mixed materials may also form an exciplex. The exciplex is preferably selected from a combination that forms an exciplex that emits light that overlaps with the wavelength of the lowest-energy absorption band of the light-emitting material, because this allows for smooth energy transfer and efficient light emission. Furthermore, this configuration is also preferable because it reduces the driving voltage.

[0093] At least one of the materials forming the exciplex may be a phosphorescent material, which allows efficient conversion of triplet excitation energy into singlet excitation energy through reverse intersystem crossing.

[0094] As a combination of materials that efficiently form an exciplex, it is preferable that the HOMO level of the material having hole transport properties is equal to or higher than the HOMO level of the material having electron transport properties. Also, it is preferable that the LUMO level of the material having hole transport properties is equal to or higher than the LUMO level of the material having electron transport properties. Note that the LUMO level and HOMO level of the material can be derived from the electrochemical properties (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV).

[0095] The formation of exciplexes can be confirmed, for example, by comparing the emission spectra of a material having hole transport properties, a material having electron transport properties, and a mixed film obtained by mixing these materials, and observing the phenomenon in which the emission spectrum of the mixed film is shifted to longer wavelengths than the emission spectra of each material (or has a new peak on the longer wavelength side). Alternatively, the formation of exciplexes can be confirmed by comparing the transient photoluminescence (PL) of a material having hole transport properties, the transient PL of a material having electron transport properties, and a mixed film obtained by mixing these materials, and observing differences in transient response, such as the transient PL lifetime of the mixed film having a longer-lifetime component or a larger proportion of delayed components than the transient PL lifetimes of the individual materials. The above-mentioned transient PL may also be interpreted as transient electroluminescence (EL). In other words, the formation of exciplexes can also be confirmed by comparing the transient EL of a material having hole transport properties, the transient EL of a material having electron transport properties, and a mixed film obtained by mixing these materials, and observing the differences in transient response.

[0096] When a hole-blocking layer is provided, the hole-blocking layer is in contact with the light-emitting layer 113 and is formed by containing an organic compound having an electron-transporting property and capable of blocking holes. The organic compound constituting the hole-blocking layer is preferably a material having an excellent electron-transporting property, a low hole-transporting property, and a deep HOMO level. Specifically, the hole-blocking layer has a HOMO level that is 0.5 eV or more deeper than the HOMO level of the material contained in the light-emitting layer 113, and an electron mobility at a square root of an electric field strength [V / cm] of 600 is 1×10 −６ cm ２ A substance having an electron mobility of 1 / Vs or more is preferred.

[0097] In particular, 2-{3-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}dibenzo[f,h]quinoxaline (abbreviation: 2mPCCzPDBq), 2-{3-[2-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}dibenzo[f,h]quinoxaline (abbreviation: 2mPCCzPDBq-02), 2-{3-[3-(N-phenyl-9H-carbazol-2-yl)-9H-carbazol-9-yl]phenyl}dibenzo[f,h]quinoxaline (abbreviation: 2 mPCCzPDBq-03), 2-{3-[3-(N-(3,5-di-tert-butylphenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}dibenzo[f,h]quinoxaline, 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPC CzPTzn-02), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: PCCzTzn(CzT)), 9-[3-(4,6-diphenyl-pyrimidin-2-yl)phenyl]-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: 2PCCzPPm), 9- (4,6-diphenyl-pyrimidin-2-yl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: 2PCCzPm), 4-[2-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]benzofuro[3,2-d]pyrimidine (abbreviation: 4PCCzBfpm-02), 4-{3-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}benzo[h]quinazoline, 9-[3-(2,6-diphenyl-pyridin-4-yl)phenyl]-9'-phenyl-3,3'-bi-9H-carbazole is preferred because it has good heat resistance.

[0098] When other materials are used for the hole blocking layer, it is preferable to use an organic compound having a HOMO level deeper than the HOMO level of the material contained in the light-emitting layer 113 from among materials that can be used for the hole transport layer described later.

[0099] The electron transport layer 114 is an organic compound having electron transport properties, and has an electron mobility of 1×10 at a square root of an electric field strength [V / cm] of 600. −６ cm ２ A substance having an electron mobility of 1 / Vs or more is preferred. Note that other substances can be used as long as they have a higher electron transporting property than holes. Note that the organic compound is preferably an organic compound having a π-electron-deficient heteroaromatic ring. The organic compound having a π-electron-deficient heteroaromatic ring is preferably, for example, one or more of an organic compound having a heteroaromatic ring with a polyazole skeleton, an organic compound having a heteroaromatic ring with a pyridine skeleton, an organic compound having a heteroaromatic ring with a diazine skeleton, and an organic compound having a heteroaromatic ring with a triazine skeleton.

[0100] Specific examples of the organic compound having a π-electron-deficient heteroaromatic ring that can be used in the electron transport layer include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3 organic compounds having an azole skeleton, such as 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), and 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs); organic compounds containing a heteroaromatic ring having a pyridine skeleton, such as 1,3,5-tri[3-(3-pyridyl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), bathophenanthroline (abbreviation: Bphen), bathocuproine (abbreviation: BCP), and 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen); [3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3′-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3′-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4′-(9-phenyl-9H-carbazol-3-yl)-3,1′-biphenyl-1-yl]dibenzo[f,h]quinoxalineh]quinoxaline (abbreviation: 2mpPCBPDBq), 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4-(3,6-diphenyl-9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), nyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 9-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 9-[(3'-dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 9,9'-[pyrimidine-4,6-diylbis(biphenyl-3,3 4,6mCzBP2Pm), 8-(1,1'-biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 3,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzofuro[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3'-(dibenzothiophen-4-yl)(1,1'-biphenyl-3-yl)]naphtho[1',2':4,5]furo[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2'-binaphthalen)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm), 2,2'-(pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6(P-Bqn)2Py) , 2,2'-(pyridine-2,6-diyl)bis{4-[4-(2-naphthyl)phenyl]-6-phenylpyrimidine} (abbreviation: 2,6(NP-PPm)2Py), 6-(1,1'-biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 2,6-bis(4-naphthalen-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 4-[3,5-bis(9H-carbazol-9-yl)phenyl ]-2-phenyl-6-(1,1'-biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 7-[4-(9-phenyl-9H-carbazol-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: PC-cgDBCzQz), 8-(1,1':4',1"-terphenyl-3-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm), 4,8-bis[3-(dibenzofuran-4-yl)phenyl] Benzofuro[3,2-d]pyrimidine, 8-(1,1':4',1"-terphenyl-3-yl)-4-[3-(dibenzothiophen-4-yl)biphenyl-4-yl]-benzofuro[3,2-d]pyrimidine, 4,8-bis[3-(9H-carbazol-9-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 4,8mCzP2Bfpm), 8-(1,1':4',1"-terphenyl-3-yl)-4-[3-(9-phenyl-9H-carbazol-3-yl)phenyl]-benzofuro[3,2-d]pyrimidine, 8-(1,1'-biphenyl-4-yl)-4-[3-(9-phenyl-9H-carbazol-3-yl)biphenyl-3-yl]-benzofuro[3,2-d]pyrimidine, 8-(1,1'-biphenyl-4-yl)-4-{3-[2-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}benzofuro[3,2-d]pyrimidine, 8-phenyl-4-{3-[2-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}benzofuro[3,2-d]pyrimidine, 8 organic compounds having a diazine skeleton such as 1,1'-biphenyl-4-yl)-4-(3,5-di-9H-carbazol-9-yl-phenyl)benzofuro[3,2-d]pyrimidine, 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)-1,1'-biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 2-[(1,1'-biphenyl)-4-yl]-4-phenyl-6-[9,9'-spirobi(9H-fluoren)-2-yl]-1,3,5-triazine (abbreviation: BP- SFTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn-02), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine 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), 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)-1,1'-biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-{3-[3-(dibenzothiophen-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTzn), 2,4,6-tris(3′-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine (abbreviation: TmPPPyTz), 2-[3-(2,6-dimethyl-3-pyridyl)-5-(9-phenanthryl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTzn), 11-(4-[1,1′-biphenyl]-4-yl-6-phenyl-1,3,5-triazin-2-yl)-11,12-dihydro-12-phenyl- Examples of organic compounds having a triazine skeleton include indolo[2,3-a]carbazole (abbreviation: BP-Icz(II)Tzn), 2-[3′-(triphenylen-2-yl)-1,1′-biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mTpBPTzn), 9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzothiophenyl]-2-phenyl-9H-carbazole (abbreviation: PCDBfTzn), and 2-[1,1′-biphenyl]-3-yl-4-phenyl-6-(8-[1,1′:4′,1″-terphenyl]-4-yl-1-dibenzofuranyl)-1,3,5-triazine (abbreviation: mBP-TPDBfTzn). Among the above, organic compounds containing a heteroaromatic ring having a diazine skeleton, organic compounds containing a heteroaromatic ring having a pyridine skeleton, and organic compounds containing a heteroaromatic ring having a triazine skeleton are preferred because of their high reliability. In particular, organic compounds containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing a heteroaromatic ring having a triazine skeleton have high electron transport properties and contribute to reducing driving voltage.

[0101] The electron transport layer 114 having this structure may also serve as the electron injection layer 115 .

[0102] Between the electron transport layer 114 and the common electrode (cathode) 102, an electron injection layer 115 is formed using lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF ２It is preferable to provide a layer containing an alkali metal or alkaline earth metal, such as 8-hydroxyquinolinato-lithium (abbreviated as Liq), or a compound or complex thereof. A co-evaporation film of ytterbium (Yb) and lithium is also preferable. The electron injection layer 115 may be an electride, in which an alkali metal or alkaline earth metal or a compound thereof is contained in a layer made of a substance having electron transport properties. Examples of electrides include a substance in which electrons are added at a high concentration to a mixed oxide of calcium and aluminum.

[0103] Note that a layer containing a substance having an electron transport property (preferably an organic compound having a bipyridine skeleton) containing a fluoride of the alkali metal or alkaline earth metal at a concentration (50 wt % or more) that results in a microcrystalline state can also be used as the electron-injection layer 115. Since this layer has a low refractive index, it is possible to provide a light-emitting device with better external quantum efficiency.

[0104] The cathode may be made of a metal, alloy, electrically conductive compound, or mixture thereof having a small work function (specifically, 3.8 eV or less). Specific examples of such cathode materials include alkali metals such as lithium (Li) or cesium (Cs), elements belonging to Group 1 or Group 2 of the periodic table such as magnesium (Mg), calcium (Ca), and strontium (Sr), alloys containing these (MgAg, AlLi), rare earth metals such as europium (Eu) and ytterbium (Yb), and alloys containing these. However, by providing an electron injection layer between the cathode and the electron transport layer, various conductive materials such as Al, Ag, ITO, and indium oxide-tin oxide containing silicon or silicon oxide can be used as the cathode, regardless of the magnitude of the work function.

[0105] These conductive materials can be formed into films by dry methods such as vacuum deposition or sputtering, inkjet methods, spin coating methods, etc. Alternatively, they may be formed by wet methods using a sol-gel method, or by wet methods using a paste of a metal material.

[0106] The EL layer 103 may be formed by any of various methods, including dry and wet methods, such as vacuum deposition, gravure printing, offset printing, screen printing, inkjet printing, and spin coating.

[0107] Furthermore, the above-mentioned electrodes or layers may be formed using different film formation methods.

[0108] The configuration of the layer provided between the anode and cathode is not limited to the above, but a configuration in which the light-emitting region where holes and electrons recombine is provided at a location away from the anode and cathode is preferred so as to suppress quenching caused by the proximity of the light-emitting region to the metal used in the electrode or carrier injection layer.

[0109] Furthermore, the hole transport layer or electron transport layer in contact with the light-emitting layer 113, particularly the carrier transport layer close to the recombination region in the light-emitting layer 113, is preferably composed of a substance having a band gap larger than the band gap of the light-emitting material constituting the light-emitting layer or the light-emitting material contained in the light-emitting layer, in order to suppress energy transfer from excitons generated in the light-emitting layer.

[0110] Note that the structure of this embodiment mode can be used in appropriate combination with structures of other embodiments.

[0111] (Embodiment 3) In this embodiment, a light-emitting device manufactured using the light-emitting device described in Embodiments 1 and 2 will be described with reference to Figures 3A and 3B. Figure 3A is a top view showing the light-emitting device, and Figure 3B is a cross-sectional view taken along dashed lines A-B and C-D in Figure 3A. This light-emitting device includes a driver circuit section (source line driver circuit) 601, a pixel section 602, and a driver circuit section (gate line driver circuit) 603, all of which are shown by dotted lines, to control light emission from the light-emitting device. Reference numeral 604 denotes a sealing substrate, 605 denotes a sealant, and the inside surrounded by the sealant 605 forms a space 607.

[0112] The routing wiring 608 is wiring for transmitting signals input to the source line driver circuit 601 and the gate line driver circuit 603, and receives video signals, clock signals, start signals, reset signals, etc. from an FPC (flexible printed circuit) 609, which serves as an external input terminal. Although only the FPC is shown here, a printed wiring board (PWB) may be attached to this FPC. In this specification, the light-emitting device includes not only the light-emitting device itself but also a state in which an FPC or PWB is attached to it.

[0113] Next, the cross-sectional structure will be described with reference to Fig. 3B. A driver circuit portion and a pixel portion are formed on an element substrate 610, and here, a source line driver circuit 601, which is the driver circuit portion, and one pixel in a pixel portion 602 are shown.

[0114] The element substrate 610 may be made of a substrate made of glass, quartz, organic resin, metal, alloy, semiconductor, or the like, or a plastic substrate made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fluoride), polyester, acrylic resin, or the like.

[0115] The structure of a transistor used in a pixel or a driver circuit is not particularly limited. For example, an inverted staggered transistor or a staggered transistor may be used. Furthermore, a top-gate transistor or a bottom-gate transistor may be used. The semiconductor material used for the transistor is not particularly limited, and examples thereof include silicon, germanium, silicon carbide, and gallium nitride. Alternatively, an oxide semiconductor containing at least one of indium, gallium, and zinc, such as an In—Ga—Zn-based metal oxide, may be used.

[0116] The crystallinity of a semiconductor material used for a transistor is not particularly limited, and any of an amorphous semiconductor and a crystalline semiconductor (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor having a crystalline region in part) may be used. The use of a crystalline semiconductor is preferable because it can suppress deterioration of transistor characteristics.

[0117] Here, it is preferable to use an oxide semiconductor for the transistors provided in the pixel or the driver circuit, as well as for semiconductor devices such as transistors used in touch sensors, which will be described later. In particular, it is preferable to use an oxide semiconductor having a wider band gap than silicon. By using an oxide semiconductor having a wider band gap than silicon, the current in the off state of the transistor can be reduced.

[0118] The oxide semiconductor preferably contains at least indium (In) or zinc (Zn), and more preferably contains an oxide represented by In-M-Zn-based oxide (M is a metal such as Al, Ti, Ga, Ge, Y, Zr, Sn, La, Ce, or Hf).

[0119] In particular, it is preferable to use, as the semiconductor layer, an oxide semiconductor film which has a plurality of crystal parts whose c-axes are oriented perpendicular to a surface on which the semiconductor layer is formed or a top surface of the semiconductor layer and which does not have grain boundaries between adjacent crystal parts.

[0120] By using such a material for the semiconductor layer, fluctuations in electrical characteristics are suppressed, and a highly reliable transistor can be realized.

[0121] Furthermore, a transistor having the above-described semiconductor layer can retain charge stored in a capacitor through the transistor for a long period of time due to its low off-state current. By applying such a transistor to a pixel, it is possible to stop the driver circuit while maintaining the gray level of an image displayed in each display region. As a result, an electronic device with extremely low power consumption can be realized.

[0122] For example, to stabilize the characteristics of a transistor, it is preferable to provide a base film. The base film can be formed as a single layer or a stacked layer using an inorganic insulating film such as a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a silicon nitride oxide film. The base film can be formed by a sputtering method, a CVD (Chemical Vapor Deposition) method (such as a plasma CVD method, a thermal CVD method, or a MOCVD (Metal Organic CVD) method), an ALD (Atomic Layer Deposition) method, a coating method, a printing method, or the like. Note that the base film need not be provided if it is not necessary.

[0123] The FET 623 indicates one of the transistors formed in the drive circuit section 601. The drive circuit may be formed of various CMOS circuits, PMOS circuits, or NMOS circuits. Although this embodiment shows a driver-integrated type in which the drive circuit is formed on a substrate, this is not necessarily required, and the drive circuit may also be formed externally rather than on the substrate.

[0124] Furthermore, the pixel portion 602 is formed by a plurality of pixels including a switching FET 611, a current control FET 612, and a first electrode 613 electrically connected to the drain of the FET, but is not limited to this, and the pixel portion may be formed by combining three or more FETs and a capacitance element.

[0125] An insulator 614 is formed to cover an end portion of the first electrode 613. Here, the insulator 614 can be formed by using a positive photosensitive acrylic resin film.

[0126] Furthermore, in order to improve the coverage of the EL layer and the like to be formed later, a curved surface having a curvature is formed at the upper or lower end of the insulator 614. For example, when a positive photosensitive acrylic resin is used as the material of the insulator 614, it is preferable to provide a curved surface having a curvature radius (0.2 μm to 3 μm) only at the upper end of the insulator 614. Furthermore, either a negative photosensitive resin or a positive photosensitive resin can be used as the insulator 614.

[0127] An EL layer 616 and a second electrode 617 are formed on the first electrode 613. Here, the first electrode 613 functions as an anode. Materials that can be used for the anode are preferably those with a large work function. For example, a single layer film such as an ITO film, an indium tin oxide film containing silicon, an indium oxide film containing 2 to 20 wt % zinc oxide, a titanium nitride film, a chromium film, a tungsten film, a Zn film, or a Pt film can be used. Other examples include a laminated structure with a silver-based film, a laminated structure with a titanium nitride film and an aluminum-based film, and a three-layer structure with a titanium nitride film, an aluminum-based film, and a titanium nitride film. The laminated structure provides low wiring resistance, good ohmic contact, and the anode can function well.

[0128] The EL layer 616 can be formed by various methods such as evaporation using an evaporation mask, ink-jet printing, spin coating, etc. The EL layer 616 has the structure described in Embodiment Mode 1 and Embodiment Mode 2.

[0129] Furthermore, a material having a small work function (Al, Mg, Li, Ca, or an alloy or compound thereof (MgAg, MgIn, AlLi, etc.)) is preferably used as a material for the second electrode 617 formed on the EL layer 616. Note that when light generated in the EL layer 616 is transmitted through the second electrode 617, it is preferable to use a stack of a thin metal or alloy film and a transparent conductive film (ITO, indium oxide containing 2 to 20 wt % zinc oxide, indium tin oxide containing silicon, zinc oxide (ZnO), etc.) as the second electrode 617.

[0130] Note that a light-emitting device is formed with the first electrode 613, the EL layer 616, and the second electrode 617. The light-emitting device is the light-emitting device described in Embodiment 1 and Embodiment 2. Note that a pixel portion is formed with a plurality of light-emitting devices, but the light-emitting device in this embodiment may include both the light-emitting devices described in Embodiments 1 and 2 and light-emitting devices having other structures. In this case, in the light-emitting device of one embodiment of the present invention, a common hole-transport layer can be used between light-emitting devices emitting light of different wavelengths, and therefore the light-emitting device can be manufactured easily and cost-effectively.

[0131] Furthermore, by bonding the sealing substrate 604 to the element substrate 610 with a sealing material 605, a structure is formed in which a light-emitting device 618 is provided in a space 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealing material 605. The space 607 is filled with a filler, and in some cases, the space is filled with an inert gas (nitrogen, argon, etc.), or with a sealing material. A recess is formed in the sealing substrate, and by providing a desiccant therein, deterioration due to the influence of moisture can be suppressed, which is a preferable configuration.

[0132] It is preferable to use an epoxy resin or glass frit for the sealing material 605. It is also desirable that these materials are as moisture- and oxygen-impermeable as possible. In addition to a glass substrate or a quartz substrate, the sealing substrate 604 can also be made of a plastic substrate made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fluoride), polyester, acrylic resin, or the like.

[0133] Although not shown in Figures 3A and 3B, a protective film may be provided on the cathode. The protective film may be formed of an organic resin film or an inorganic insulating film. The protective film may also be formed so as to cover the exposed portion of the sealing material 605. The protective film may also be provided so as to cover the surfaces and side surfaces of the pair of substrates, the exposed side surfaces of the sealing layer, the insulating layer, etc.

[0134] The protective film can be made of a material that is impermeable to impurities such as water, and therefore can effectively prevent impurities such as water from diffusing from the outside to the inside.

[0135] The protective film may be made of an oxide, nitride, fluoride, sulfide, ternary compound, metal, polymer, or the like. For example, a material containing aluminum oxide, hafnium oxide, hafnium silicate, lanthanum oxide, silicon oxide, strontium titanate, tantalum oxide, titanium oxide, zinc oxide, niobium oxide, zirconium oxide, tin oxide, yttrium oxide, cerium oxide, scandium oxide, erbium oxide, vanadium oxide, indium oxide, or the like; a material containing aluminum nitride, hafnium nitride, silicon nitride, tantalum nitride, titanium nitride, niobium nitride, molybdenum nitride, zirconium nitride, or gallium nitride, or the like; a nitride containing titanium and aluminum, an oxide containing titanium and aluminum, an oxide containing aluminum and zinc, a sulfide containing manganese and zinc, a sulfide containing cerium and strontium, an oxide containing erbium and aluminum, or an oxide containing yttrium and zirconium, or the like.

[0136] The protective film is preferably formed using a film formation method that provides good step coverage. One such method is atomic layer deposition (ALD). It is preferable to use a material that can be formed using the ALD method for the protective film. By using the ALD method, it is possible to form a dense protective film with reduced defects such as cracks or pinholes, or with a uniform thickness. Furthermore, it is possible to reduce damage to the workpiece when forming the protective film.

[0137] For example, by forming a protective film using the ALD method, it is possible to form a uniform protective film with few defects on surfaces having complex uneven shapes, including the top, side, and back surfaces of the touch panel.

[0138] In the above manner, a light-emitting device manufactured using the light-emitting device described in Embodiments 1 and 2 can be obtained.

[0139] The light-emitting device in this embodiment uses the light-emitting devices described in Embodiments 1 and 2, and therefore, a light-emitting device with good characteristics can be obtained. Specifically, the light-emitting devices described in Embodiments 1 and 2 have good luminous efficiency, and therefore, a light-emitting device with low power consumption can be obtained. In addition, a light-emitting device with good display quality can be obtained.

[0140] 4A and 4B show an example of a light-emitting device in which color purity is improved by providing a colored layer (color filter), etc. Fig. 4A illustrates a substrate 1001, a base insulating film 1002, a gate insulating film 1003, gate electrodes 1006, 1007, and 1008, a first interlayer insulating film 1020, a second interlayer insulating film 1021, a peripheral portion 1042, a pixel portion 1040, a driver circuit portion 1041, anodes 1024R, 1024G, and 1024B of the light-emitting device, a partition wall 1025, an EL layer 1028, a common electrode (cathode) 1029 of the light-emitting device, a sealing substrate 1031, a sealant 1032, and the like.

[0141] 4A , the colored layers (red colored layer 1034R, green colored layer 1034G, and blue colored layer 1034B) are provided on a transparent base material 1033. A black matrix 1035 may also be provided. The transparent base material 1033 provided with the colored layers and black matrix is ​​aligned and fixed to the substrate 1001. The colored layers and black matrix 1035 are covered with an overcoat layer 1036.

[0142] 4B shows an example in which colored layers (a red colored layer 1034R, a green colored layer 1034G, and a blue colored layer 1034B) are formed between the gate insulating film 1003 and the first interlayer insulating film 1020. In this manner, the colored layers may be provided between the substrate 1001 and the sealing substrate 1031.

[0143] Furthermore, the light-emitting device described above has a structure (bottom emission type) in which light is extracted from the substrate 1001 on which the FET is formed, but a structure (top emission type) in which light is extracted from the sealing substrate 1031 side may also be used. A cross-sectional view of a top emission type light-emitting device is shown in FIG. 5 . In this case, a light-opaque substrate can be used as the substrate 1001. The process is performed in the same manner as for a bottom emission type light-emitting device until a connection electrode connecting the FET and the anode of the light-emitting device is formed. Thereafter, a third interlayer insulating film 1037 is formed to cover the electrode 1022. This insulating film may also serve as a planarizing film. The third interlayer insulating film 1037 can be formed using the same material as the second interlayer insulating film, as well as other known materials.

[0144] Although the anodes 1024R, 1024G, and 1024B of the light-emitting device are herein referred to as anodes, they may be cathodes. In the case of a top-emission light-emitting device such as that shown in FIG. 5, the anodes are preferably reflective electrodes. The EL layer 1028 has the same structure as that described for the EL layer 103 in the first embodiment.

[0145] In the top-emission structure shown in FIG. 5 , sealing can be performed using a sealing substrate 1031 provided with colored layers (a red colored layer 1034R, a green colored layer 1034G, and a blue colored layer 1034B). The sealing substrate 1031 may be provided with a black matrix 1035 positioned between pixels. The colored layers (the red colored layer 1034R, the green colored layer 1034G, and the blue colored layer 1034B) or the black matrix may be covered with an overcoat layer (not shown). Note that a light-transmitting substrate is used as the sealing substrate 1031.

[0146] A microcavity structure is suitable for use in top-emission light-emitting devices. A light-emitting device with a microcavity structure can be obtained by using one electrode including a reflective electrode and the other electrode as a semi-transparent / semi-reflective electrode. At least an EL layer is present between the reflective electrode and the semi-transparent / semi-reflective electrode, and at least a light-emitting layer that serves as a light-emitting region is present.

[0147] The reflectance of the reflective electrode to visible light is 40% to 100%, preferably 70% to 100%, and the resistivity is 1×10 −２ The semi-transmitting and semi-reflective electrode has a visible light reflectance of 20% to 80%, preferably 40% to 70%, and a resistivity of 1×10 −２ It is assumed that the film has a resistivity of Ωcm or less.

[0148] Light emitted from the light-emitting layer included in the EL layer is reflected by the reflective electrode and the semi-transmissive and semi-reflective electrode, causing resonance.

[0149] In the light-emitting device, the optical distance between the reflective electrode and the semi-transmitting / semi-reflective electrode can be changed by changing the thickness of the transparent conductive film or the above-mentioned composite material, carrier transport material, etc. This makes it possible to intensify light of a resonant wavelength and attenuate light of a non-resonant wavelength between the reflective electrode and the semi-transmitting / semi-reflective electrode.

[0150] Note that, since the light reflected by the reflective electrode and returned (first reflected light) significantly interferes with the light (first incident light) that directly enters the semi-transmissive / semi-reflective electrode from the light-emitting layer, it is preferable to adjust the optical distance between the reflective electrode and the light-emitting layer to (2n-1)λ / 4 (where n is a natural number of 1 or more, and λ is the wavelength of the light emission to be amplified). By adjusting the optical distance, the phases of the first reflected light and the first incident light can be matched, thereby further amplifying the light emission from the light-emitting layer.

[0151] In the above configuration, the EL layer may have a structure having multiple light-emitting layers or a structure having a single light-emitting layer. For example, it may be combined with the above-mentioned tandem light-emitting device configuration, in which multiple EL layers are provided in one light-emitting device with a charge-generating layer sandwiched therebetween, and one or more light-emitting layers are formed in each EL layer.

[0152] The microcavity structure makes it possible to increase the light emission intensity of a specific wavelength in the front direction, thereby reducing power consumption. In the case of a light-emitting device that displays images using four sub-pixels of red, yellow, green, and blue, the yellow light emission has the effect of improving brightness, and the microcavity structure that matches the wavelength of each color can be applied to all sub-pixels, resulting in a light-emitting device with good characteristics.

[0153] The light-emitting device in this embodiment uses the light-emitting devices described in Embodiments 1 and 2, and therefore, a light-emitting device with good characteristics can be obtained. Specifically, the light-emitting devices described in Embodiments 1 and 2 have good luminous efficiency, and therefore, a light-emitting device with low power consumption can be obtained. In addition, a light-emitting device with good display quality can be obtained.

[0154] Up to this point, active matrix light-emitting devices have been described. From now on, passive matrix light-emitting devices will be described. Figures 6A and 6B show a passive matrix light-emitting device manufactured by applying the present invention. Note that Figure 6A is a perspective view of the light-emitting device, and Figure 6B is a cross-sectional view of Figure 6A taken along the dashed-dotted line X-Y. In Figure 6, an EL layer 955 is provided between an electrode 952 and an electrode 956 on a substrate 951. An end of the electrode 952 is covered with an insulating layer 953. A partition layer 954 is provided on the insulating layer 953. The sidewalls of the partition layer 954 are inclined such that the distance between one sidewall and the other sidewall becomes narrower as the distance approaches the substrate surface. That is, the cross section of the partition layer 954 in the short side direction is trapezoidal, and the bottom side (the side facing the same direction as the surface of the insulating layer 953 and in contact with the insulating layer 953) is shorter than the top side (the side facing the same direction as the surface of the insulating layer 953 and not in contact with the insulating layer 953). By providing the partition layer 954 in this manner, defects in the light-emitting device due to static electricity or the like can be prevented. Furthermore, the light-emitting devices described in Embodiments 1 and 2 are used in passive matrix light-emitting devices, and light-emitting devices with good display quality or low power consumption can be obtained.

[0155] The light emitting device described above is capable of individually controlling a large number of minute light emitting devices arranged in a matrix, and is therefore suitable for use as a display device for displaying images.

[0156] This embodiment mode can be freely combined with other embodiment modes.

[0157] Embodiment 4 [Light-Emitting Device] Hereinafter, another example of a light-emitting device according to one embodiment of the present invention using the light-emitting device described in Embodiments 1 and 2 and a manufacturing method thereof will be described.

[0158] 7A is a schematic top view of a light-emitting device 450 according to one embodiment of the present invention. The light-emitting device 450 includes a plurality of red light-emitting devices 110R, a plurality of green light-emitting devices 110G, and a plurality of blue light-emitting devices 110B. In FIG. 7A, the light-emitting regions of the light-emitting devices are labeled with R, G, and B to easily distinguish the light-emitting devices from one another.

[0159] The light-emitting devices 110R, 110G, and 110B are arranged in a matrix. Fig. 7A shows a so-called stripe arrangement in which light-emitting devices of the same color are arranged in one direction. Note that the arrangement of the light-emitting devices is not limited to this, and other arrangements such as a delta arrangement or a zigzag arrangement may also be used, or a pentile arrangement may also be used.

[0160] The light emitting devices 110R, 110G, and 110B are arranged in the X direction. In the Y direction intersecting the X direction, light emitting devices of the same color are arranged.

[0161] The light emitting device 110R, the light emitting device 110G, and the light emitting device 110B are light emitting devices having the above-described configuration.

[0162] 7B is a schematic cross-sectional view corresponding to the dashed-dotted line A1-A2 in FIG. 7A, and FIG. 7C is a schematic cross-sectional view corresponding to the dashed-dotted line B1-B2.

[0163] 7B shows cross sections of the light-emitting device 110R, the light-emitting device 110G, and the light-emitting device 110B. The light-emitting device 110R has a pixel electrode (anode) 101R, a first EL layer 120R, a second EL layer 121, and a common electrode 102. The light-emitting device 110G has a pixel electrode (anode) 101G, a first EL layer 120G, a second EL layer (electron injection layer) 121, and a common electrode 102. The light-emitting device 110B has a pixel electrode (anode) 101B, a first EL layer 120B, a second EL layer 121, and a common electrode 102. The second EL layer 121 and the common electrode 102 are provided in common to the light-emitting device 110R, the light-emitting device 110G, and the light-emitting device 110B. The second EL layer 121 can also be referred to as a common layer.

[0164] The first EL layer 120R of the light-emitting device 110R contains a light-emitting organic compound that emits light having an intensity in at least a red wavelength range. The first EL layer 120G of the light-emitting device 110G contains a light-emitting organic compound that emits light having an intensity in at least a green wavelength range. The first EL layer 120B of the light-emitting device 110B contains a light-emitting organic compound that emits light having an intensity in at least a blue wavelength range. Of the light-emitting devices 110R, 110G, and 110B, at least the light-emitting device 110R is a light-emitting device according to one embodiment of the present invention.

[0165] The first EL layer 120R, the first EL layer 120G, and the first EL layer 120B each have at least a light-emitting layer and may additionally have one or more of a hole-blocking layer, an electron-injecting layer, an electron-transporting layer, a hole-transporting layer, a hole-injecting layer, an electron-blocking layer, an exciton-blocking layer, and the like. The second EL layer 121 does not have a light-emitting layer. The second EL layer 121 is preferably an electron-injecting layer. Note that when the surfaces of the first EL layer 120R, the first EL layer 120G, and the first EL layer 120B on the second electrode side also function as an electron-injecting layer, the second EL layer 121 does not need to be provided.

[0166] The pixel electrode (anode) 101R, pixel electrode (anode) 101G, and pixel electrode (anode) 101B are provided for each light-emitting device. The common electrode 102 and the second EL layer 121 are preferably provided as a continuous layer common to each light-emitting device. The hole transport layer in the first EL layer 120 is preferably discontinued between light-emitting devices emitting different colors, but has the same configuration.

[0167] A conductive film that is transparent to visible light is used for either the pixel electrode 101 or the common electrode 102, and a conductive film that is reflective is used for the other. By making the pixel electrode 101 light-transmitting and the common electrode 102 reflective, a bottom-emission display device can be obtained. Conversely, by making each pixel electrode reflective and the common electrode 102 light-transmitting, a top-emission display device can be obtained. Note that by making both each pixel electrode and the common electrode 102 light-transmitting, a dual-emission display device can also be obtained. The light-emitting device of one embodiment of the present invention is suitable for a top-emission light-emitting device.

[0168] The first EL layer 120R, the first EL layer 120G, and the first EL layer 120B are provided to cover the ends of the pixel electrode 101R, the pixel electrode 101G, and the pixel electrode 101B, respectively. An insulating layer 125 is provided to cover the ends of the first EL layer 120R, the first EL layer 120G, and the first EL layer 120B. In other words, the insulating layer 125 has openings that overlap with the pixel electrodes 101R, 101G, and 101B and the first EL layer 120R, the first EL layer 120G, and the first EL layer 120B. The ends of the openings of the insulating layer 125 are preferably tapered. The ends of the pixel electrodes 101R, 101G, and 101B do not have to be covered with the first EL layer 120R, 120G, and 120B, respectively.

[0169] The first EL layer 120R, the first EL layer 120G, and the first EL layer 120B have regions in contact with the upper surfaces of the pixel electrode 101R, the pixel electrode 101G, and the pixel electrode 101B, respectively. In addition, ends of the first EL layer 120R, the first EL layer 120G, and the first EL layer 120B are located below the insulating layer 125. The upper surfaces of the first EL layer 120R, the first EL layer 120G, and the first EL layer 120B have regions in contact with the insulating layer 125 and regions in contact with the second EL layer 121 (or the common electrode 102 in the case where the second EL layer is not provided).

[0170] FIG. 18 is a modified example of FIG. 7B . In FIG. 18 , the ends of the pixel electrodes 101R, 101G, and 101B have a tapered shape that widens toward the substrate, improving coverage of films formed thereon. The ends of the pixel electrodes 101R, 101G, and 101B are covered with the first EL layers 120R, 120G, and 120B, respectively. A mask layer 107 is formed covering the EL layers. This serves to prevent damage to the EL layers during etching by photolithography. An insulating layer 108 is provided between the light-emitting devices 110R, 110G, and 110B. The ends of the insulating layer 108 have a gently tapered shape, preventing discontinuities in the second EL layer 121 and common electrode 102 that will be formed later.

[0171] As shown in Figures 7B and 18, a gap is provided between the two EL layers of light-emitting devices of different colors. In this manner, it is preferable that the first EL layer 120R, the first EL layer 120G, and the first EL layer 120B are arranged so as not to contact each other. This effectively prevents current from flowing through the two adjacent EL layers, thereby preventing unintended light emission. This improves contrast and realizes a display device with high display quality. Furthermore, by using photolithography to fabricate the gap between the edges of the opposing EL layers of adjacent light-emitting devices (e.g., light-emitting device 110R and light-emitting device 110G), it is possible to set the gap between 2 μm or more and 5 μm or less. This can also be referred to as the gap between the light-emitting layers included in the EL layer. It is difficult to achieve a gap of less than 10 μm using a metal mask formation method.

[0172] In this way, by fabricating a light-emitting device using photolithography, the area of ​​a non-light-emitting region that may exist between two light-emitting devices can be significantly reduced, and the aperture ratio can be significantly increased. For example, in a display device according to one embodiment of the present invention, the aperture ratio can be 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, or even 90% or more, but less than 100%.

[0173] Increasing the aperture ratio of a display device can improve the reliability of the display device. More specifically, when the lifetime of a display device using an organic EL device and having an aperture ratio of 10% is taken as the reference, the lifetime of a display device having an aperture ratio of 20% (i.e., an aperture ratio twice as high as the reference) is approximately 3.25 times longer, and the lifetime of a display device having an aperture ratio of 40% (i.e., an aperture ratio four times as high as the reference) is approximately 10.6 times longer. As such, as the aperture ratio increases, the current density flowing through the organic EL device can be reduced, thereby improving the lifetime of the display device. In the display device of one embodiment of the present invention, the aperture ratio can be increased, thereby improving the display quality of the display device. Furthermore, as the aperture ratio of the display device increases, an excellent effect is achieved, such as a significant improvement in the reliability (particularly the lifetime) of the display device.

[0174] 7C shows an example in which the EL layer 120R is formed so as to be separated for each light-emitting device in the Y direction. While FIG. 7C shows a cross section of the light-emitting device 110R as an example, the light-emitting device 110G and the light-emitting device 110B may also have a similar shape. The EL layer may be continuous in the Y direction, and the EL layer 120R may be formed in a strip shape. By forming the EL layer 120R or the like in a strip shape, no space is required to separate them, and the area of ​​the non-light-emitting region between the light-emitting devices can be reduced, thereby increasing the aperture ratio.

[0175] A protective layer 131 is provided on the common electrode 102 to cover the light-emitting device 110R, the light-emitting device 110G, and the light-emitting device 110B. The protective layer 131 has a function of preventing impurities such as water from diffusing from above into each light-emitting device.

[0176] The protective layer 131 may have, for example, a single-layer structure or a stacked structure including at least an inorganic insulating film. Examples of the inorganic insulating film include oxide films or nitride films such as a silicon oxide film, a silicon oxynitride film, a silicon nitride oxide film, a silicon nitride film, an aluminum oxide film, an aluminum oxynitride film, and a hafnium oxide film. Alternatively, the protective layer 131 may be made of a semiconductor material such as indium gallium oxide or indium gallium zinc oxide.

[0177] Alternatively, the protective layer 131 may be a laminated film of an inorganic insulating film and an organic insulating film. For example, a configuration in which an organic insulating film is sandwiched between a pair of inorganic insulating films is preferable. Furthermore, it is preferable that the organic insulating film functions as a planarizing film. This allows the upper surface of the organic insulating film to be flat, thereby improving the coverage of the inorganic insulating film thereon and enhancing the barrier properties. Furthermore, since the upper surface of the protective layer 131 is flat, when a structure (e.g., a color filter, a touch sensor electrode, a lens array, etc.) is provided above the protective layer 131, the influence of uneven shapes caused by the structure below can be reduced, which is preferable.

[0178] 7A also shows a connection electrode 101C that is electrically connected to the common electrode 102. The connection electrode 101C is given a potential (e.g., an anode potential or a cathode potential) to be supplied to the common electrode 102. The connection electrode 101C is provided outside the display area where the light-emitting devices 110R and the like are arranged. In addition, in FIG. 7A, the common electrode 102 is shown by a dashed line.

[0179] The connection electrode 101C can be provided along the periphery of the display area. For example, it may be provided along one side of the periphery of the display area, or it may be provided over two or more sides of the periphery of the display area. That is, when the top surface shape of the display area is rectangular, the top surface shape of the connection electrode 101C can be strip-shaped, L-shaped, U-shaped (square bracket-shaped), square-shaped, or the like.

[0180] Fig. 7D is a schematic cross-sectional view corresponding to dashed dotted line C1-C2 in Fig. 7A. Fig. 7D shows a connection portion 130 where the connection electrode 101C and the common electrode 102 are electrically connected. In the connection portion 130, the common electrode 102 is provided in contact with the connection electrode 101C, and a protective layer 131 is provided covering the common electrode 102. In addition, an insulating layer 124 is provided covering the end of the connection electrode 101C.

[0181] [Manufacturing Method Example 1] An example of a manufacturing method of a display device according to one embodiment of the present invention will be described below with reference to the drawings. Here, the light-emitting device 450 shown in the above configuration example will be described as an example. Figures 8A to 9F are cross-sectional schematic views of each step in the manufacturing method of the display device exemplified below. Also, in Figure 8A and other figures, a cross-sectional schematic view of the connection portion 130 and its vicinity is also shown on the right side.

[0182] Thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device can be formed using a sputtering method, a chemical vapor deposition (CVD) method, a vacuum evaporation method, a pulsed laser deposition (PLD) method, an atomic layer deposition (ALD) method, etc. CVD methods include a plasma enhanced chemical vapor deposition (PECVD) method and a thermal CVD method. One type of thermal CVD method is a metal organic chemical vapor deposition (MOCVD) method.

[0183] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device can be formed by methods such as spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, knife coating, etc.

[0184] Furthermore, when processing the thin film that constitutes the display device, a photolithography method or the like can be used. Alternatively, the thin film may be processed by a nanoimprint method, a sandblasting method, a lift-off method, or the like. Furthermore, the island-shaped thin film may be directly formed by a film formation method using a shielding mask such as a metal mask.

[0185] There are two typical photolithography methods: one is to form a resist mask on the thin film to be processed, process the thin film by etching or the like, and then remove the resist mask; the other is to form a photosensitive thin film, and then process the thin film into the desired shape by exposure and development.

[0186] In photolithography, the light used for exposure may be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these. Other light sources that can be used include ultraviolet light, KrF laser light, ArF laser light, etc. Exposure may also be performed by immersion exposure technology. Extreme ultraviolet (EUV) light, X-rays, etc. may also be used as light for exposure. An electron beam may also be used instead of light for exposure. Extreme ultraviolet light, X-rays, or an electron beam are preferred because they enable extremely fine processing. When exposure is performed by scanning a beam such as an electron beam, a photomask is not required.

[0187] For etching the thin film, dry etching, wet etching, sandblasting, or the like can be used.

[0188] In this specification, etc., a device fabricated using a metal mask or an FMM (fine metal mask, high-resolution metal mask) may be referred to as a device with an MM (metal mask) structure. In addition, in this specification, etc., a device fabricated without using a metal mask or an FMM may be referred to as a device with an MML (metal maskless) structure.

[0189] [Preparation of Substrate 100] A substrate having heat resistance sufficient to withstand at least subsequent heat treatment can be used as the substrate 100. When an insulating substrate is used as the substrate 100, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, an organic resin substrate, or the like can be used. In addition, a semiconductor substrate such as a single crystal semiconductor substrate made of silicon, silicon carbide, or the like, a polycrystalline semiconductor substrate, a compound semiconductor substrate such as silicon germanium, or an SOI substrate can be used.

[0190] In particular, it is preferable to use a substrate in which a semiconductor circuit including semiconductor elements such as transistors is formed on the semiconductor substrate or insulating substrate as the substrate 100. The semiconductor circuit preferably constitutes, for example, a pixel circuit, a gate line driving circuit (gate driver), a source line driving circuit (source driver), etc. In addition to the above, an arithmetic circuit, a memory circuit, etc. may also be constituted.

[0191] [Formation of pixel electrodes 101R, 101G, 101B, and connection electrode 101C] Next, the pixel electrodes 101R, 101G, 101B, and connection electrode 101C are formed on the substrate 100. First, a conductive film that will become the pixel electrodes (anodes) is formed, a resist mask is formed by photolithography, and unnecessary portions of the conductive film are removed by etching. Then, the resist mask is removed, thereby forming the pixel electrodes 101R, 101G, and 101B.

[0192] When a conductive film reflective to visible light is used as each pixel electrode, it is preferable to use a material (e.g., silver or aluminum) with as high a reflectivity as possible across the entire wavelength range of visible light. This not only increases the light extraction efficiency of the light-emitting device but also improves color reproducibility. When a conductive film reflective to visible light is used as each pixel electrode, a so-called top-emission light-emitting device can be obtained, in which light is extracted in the direction away from the substrate. When a light-transmitting conductive film is used as each pixel electrode, a so-called bottom-emission light-emitting device can be obtained, in which light is extracted toward the substrate.

[0193] [Formation of EL Film 120Rb] Subsequently, the EL film 120Rb, which will later become the EL layer 120R, is formed on the pixel electrodes 101R, 101G, and 101B.

[0194] The EL film 120Rb has at least a light-emitting layer containing a light-emitting material and a hole-transport layer. Alternatively, the EL film 120Rb may have a laminated structure of one or more films functioning as an electron injection layer, an electron transport layer, a charge generation layer, or a hole-injection layer. The EL film 120Rb can be formed by, for example, a vapor deposition method, a sputtering method, an inkjet method, or the like. However, the method is not limited to these, and the above-described film formation methods can be used as appropriate.

[0195] For example, the EL film 120Rb is preferably a stacked film in which a hole injection layer, a hole transport layer, a light-emitting layer, and an electron transport layer are stacked in this order. In this case, a film having an electron injection layer can be used as the EL layer 121 to be formed later.

[0196] It is preferable that the EL film 120Rb is formed so as not to be provided on the connection electrode 101C. For example, when the EL film 120Rb is formed by a vapor deposition method (or a sputtering method), it is preferable that the EL film 120Rb is formed using a shielding mask or removed in a subsequent etching step so that the EL film 120Rb is not formed on the connection electrode 101C.

[0197] [Formation of Mask Film 144a] Subsequently, a mask film 144a is formed to cover the EL film 120Rb. The mask film 144a is provided in contact with the upper surface of the connection electrode 101C.

[0198] The mask film 144a can be a film that is highly resistant to the etching process of each EL film, such as the EL film 120Rb, i.e., a film with a large etching selectivity. The mask film 144a can also be a film that has a large etching selectivity with respect to a protective film, such as the protective film 146a described below. Furthermore, the mask film 144a can be a film that can be removed by wet etching, which causes little damage to each EL film.

[0199] The mask film 144a may be, for example, a metal film, an alloy film, a metal oxide film, a semiconductor film, an inorganic insulating film, etc. The mask film 144a may be formed by various film formation methods such as a sputtering method, a vapor deposition method, a CVD method, an ALD method, etc.

[0200] The mask film 144a may be made of a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, or tantalum, or an alloy material containing such a metal material. In particular, it is preferable to use a low-melting-point material such as aluminum or silver.

[0201] The mask film 144a can be made of a metal oxide such as indium gallium zinc oxide (In—Ga—Zn oxide, also referred to as IGZO). Other examples include indium oxide, indium zinc oxide (In—Zn oxide), indium tin oxide (In—Sn oxide), indium titanium oxide (In—Ti oxide), indium tin zinc oxide (In—Sn—Zn oxide), indium titanium zinc oxide (In—Ti—Zn oxide), and indium gallium tin zinc oxide (In—Ga—Sn—Zn oxide). Alternatively, indium tin oxide containing silicon can be used.

[0202] The present invention can also be applied to a case where, instead of the gallium, an element M (wherein M is one or more elements selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) is used. In particular, it is preferable that M is one or more elements selected from gallium, aluminum, and yttrium.

[0203] The mask film 144a may be made of an inorganic insulating material such as aluminum oxide, hafnium oxide, silicon oxide, etc. Among these, aluminum oxide is particularly preferable.

[0204] Furthermore, it is preferable to use a material that can be dissolved in a chemically stable solvent for the mask film 144a, at least for the film located at the top of the EL film 120Rb. In particular, a material that dissolves in water or alcohol is suitable for use as the mask film 144a. When forming the mask film 144a, it is preferable to apply the mask film 144a by a wet film formation method while the mask film 144a is dissolved in a solvent such as water or alcohol, and then perform a heat treatment to evaporate the solvent. In this case, performing the heat treatment under a reduced pressure atmosphere is preferable because it allows the solvent to be removed at a low temperature and in a short time, thereby reducing thermal damage to the EL film 120Rb.

[0205] Wet film formation methods that can be used to form the mask film 144a include spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, knife coating, etc.

[0206] The mask film 144a may be made of an organic material such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinyl pyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin.

[0207] Here, a film produced by the ALD method is particularly suitable as a mask film because it is dense and has a high function of protecting the EL layer, and an aluminum oxide film is particularly suitable.

[0208] [Formation of Protective Film 146a] Subsequently, a protective film 146a is formed on the mask film 144a (FIG. 8B).

[0209] The protective film 146a is a film that is used as a hard mask when etching the mask film 144a later. Furthermore, when processing the protective film 146a later, the mask film 144a is exposed. Therefore, a combination of films that have a large etching selectivity relative to each other is selected for the mask film 144a and the protective film 146a. Therefore, a film that can be used for the protective film 146a can be selected depending on the etching conditions for the mask film 144a and the etching conditions for the protective film 146a.

[0210] For example, when dry etching using a gas containing fluorine (also referred to as a fluorine-based gas) is used to etch the protective film 146a, silicon, silicon nitride, silicon oxide, tungsten, titanium, molybdenum, tantalum, tantalum nitride, an alloy containing molybdenum and niobium, an alloy containing molybdenum and tungsten, or the like can be used for the protective film 146a. Here, examples of films that can achieve a large etching selectivity (i.e., a slower etching rate) compared to dry etching using the fluorine-based gas include metal oxide films such as IGZO and ITO, which can be used for the mask film 144a.

[0211] However, the protective film 146a is not limited to this, and can be selected from various materials depending on the etching conditions of the mask film 144a and the etching conditions of the protective film 146a. For example, it can be selected from films that can be used for the mask film 144a.

[0212] The protective film 146a may be, for example, a nitride film, such as silicon nitride, aluminum nitride, hafnium nitride, titanium nitride, tantalum nitride, tungsten nitride, gallium nitride, or germanium nitride.

[0213] Alternatively, an oxide film can be used as the protective film 146a. Typically, an oxide film or an oxynitride film such as silicon oxide, silicon oxynitride, aluminum oxide, aluminum oxynitride, hafnium oxide, or hafnium oxynitride can be used.

[0214] Alternatively, the protective film 146a may be an organic film that can be used for the EL film 120Rb, etc. For example, the same organic film as that used for the EL film 120Rb, EL film 120Gb, or EL film 120Bb may be used for the protective film 146a. Using such an organic film is preferable because it allows the same film-forming equipment to be used for the EL film 120Rb, etc.

[0215] [Formation of Resist Mask 143a] Subsequently, resist masks 143a are formed on the protective film 146a at positions overlapping the pixel electrode 101R and the connection electrode 101C (FIG. 8C).

[0216] The resist mask 143a can be made of a resist material containing a photosensitive resin, such as a positive resist material or a negative resist material.

[0217] Here, if the resist mask 143a is formed on the mask film 144a without the protective film 146a, there is a risk that the EL film 120Rb will be dissolved by the solvent of the resist material if there are defects such as pinholes in the mask film 144a. By using the protective film 146a, it is possible to prevent such problems from occurring.

[0218] When a film that is less likely to have defects such as pinholes is used as the mask film 144a, the resist mask 143a may be formed directly on the mask film 144a without using the protective film 146a.

[0219] [Etching of Protective Film 146a] Subsequently, a portion of the protective film 146a that is not covered by the resist mask 143a is removed by etching to form a strip-shaped protective layer 147a. At the same time, the protective layer 147a is also formed on the connection electrode 101C.

[0220] When etching the protective film 146a, it is preferable to use etching conditions with a high selectivity so that the mask film 144a is not removed by the etching. The protective film 146a can be etched by wet etching or dry etching, but using dry etching can prevent the pattern of the protective film 146a from shrinking.

[0221] [Removal of Resist Mask 143a] Subsequently, the resist mask 143a is removed (FIG. 8D).

[0222] The resist mask 143a can be removed by wet etching or dry etching. In particular, the resist mask 143a is preferably removed by dry etching (also called plasma ashing) using oxygen gas as an etching gas.

[0223] At this time, the resist mask 143a is removed while the EL film 120Rb is covered with the mask film 144a, so that the influence on the EL film 120Rb is suppressed. In particular, if the EL film 120Rb comes into contact with oxygen, it may have an adverse effect on the electrical characteristics, so this is suitable for use in etching using oxygen gas, such as plasma ashing.

[0224] [Etching of Mask Film 144a] Next, using the protective layer 147a as a mask, a portion of the mask film 144a that is not covered by the protective layer 147a is removed by etching to form a strip-shaped mask layer 145a (FIG. 8E). At this time, the mask layer 145a is also formed on the connection electrode 101C.

[0225] The mask film 144a can be etched by wet etching or dry etching, but dry etching is preferable because it can prevent the pattern from shrinking.

[0226] [Etching of EL film 120Rb and protective layer 147a] Next, while the protective layer 147a is being etched, a portion of the EL film 120Rb that is not covered by the mask layer 145a is simultaneously removed by etching to form a strip-shaped EL layer 120R (FIG. 8F). At this time, the protective layer 147a on the connection electrode 101C is also removed.

[0227] Etching the EL film 120Rb and the protective layer 147a in the same process is preferable because it is possible to simplify the process and reduce the manufacturing cost of the display device.

[0228] In particular, it is preferable to use dry etching using an etching gas that does not contain oxygen as a main component for etching the EL film 120Rb. This makes it possible to suppress deterioration of the EL film 120Rb and realize a highly reliable display device. Examples of etching gases that do not contain oxygen as a main component include CF ４ , C ４ F ８ , SF ６ , CHF ３ , Cl ２ , H ２ O, BCl ３ , H ２ Alternatively, a noble gas such as He may be used. Also, a mixed gas of the above gas and a dilution gas that does not contain oxygen may be used as the etching gas.

[0229] The EL film 120Rb and the protective layer 147a may be etched separately. In this case, the EL film 120Rb may be etched first, or the protective layer 147a may be etched first.

[0230] At this point, the EL layer 120R and the connection electrode 101C are covered with the mask layer 145a.

[0231] [Formation of EL Layers 120G and 120B] By repeating the same steps, island-shaped EL layers 120G and 120B and island-shaped mask layers 145b and 145c can be formed (FIG. 9A).

[0232] [Removal of Mask Layers] Subsequently, the insulating layer 126b is formed on the mask layers 145a, 145b, and 145c. The insulating layer 126b can be formed in the same manner as the mask layers 145a, 145b, and 145c.

[0233] [Formation of Insulating Layer 125b] Then, the insulating layer 125b is formed to cover the insulating layer 126b. The insulating layer 125b may be formed using a photosensitive organic resin. Examples of the organic material include acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimideamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins. The insulating layer 125b may be formed using an organic material such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin. A photoresist may be used as the photosensitive resin. The photosensitive resin may be a positive-type material or a negative-type material.

[0234] The insulating layer 125b is preferably subjected to heat treatment after application. The heat treatment is performed at a temperature lower than the heat resistance temperature of the EL layer. The substrate temperature during the heat treatment may be 50° C. or higher and 200° C. or lower, preferably 60° C. or higher and 150° C. or lower, and more preferably 70° C. or higher and 120° C. or lower. This allows the solvent contained in the insulating layer 125b to be removed.

[0235] 7C , exposure and development are performed to form openings 128 in the regions of the insulating layer 125b that overlap with the pixel electrodes and the first EL layer, thereby forming the insulating layer 125. When a positive acrylic resin is used for the insulating layer 125b, visible light or ultraviolet light may be irradiated using a mask onto the regions where the insulating layer 125b is to be removed.

[0236] When visible light is used for exposure, the visible light preferably includes i-line (wavelength 365 nm). Visible light including g-line (wavelength 436 nm) or h-line (wavelength 405 nm) may also be used.

[0237] When an acrylic resin is used for the insulating layer 125b, an alkaline solution is preferably used as a developer, such as an aqueous solution of tetramethylammonium hydroxide (TMAH).

[0238] After that, it is preferable to expose the entire substrate to visible light or ultraviolet light and irradiate the insulating layer 125. The energy density of the exposure is 0 mJ / cm. ２ Larger than 800 mJ / cm ２ or less, 0 mJ / cm ２ Greater than 500 mJ / cm ２ By performing such exposure after development, the transparency of the insulating layer 125 can be improved in some cases. In addition, the substrate temperature required for heat treatment in a later step for transforming the end portions of the insulating layer 125 into a tapered shape can be reduced in some cases.

[0239] Next, heat treatment can be performed to transform the insulating layer 125b into an insulating layer 125 having tapered side surfaces. The heat treatment is performed at a temperature lower than the heat resistance temperature of the EL layer. The substrate temperature during the heat treatment may be 50° C. or higher and 200° C. or lower, preferably 60° C. or higher and 150° C. or lower, and more preferably 70° C. or higher and 130° C. or lower. The substrate temperature during the heat treatment in this step is preferably higher than that during the heat treatment performed after the application of the insulating layer 125. This can also improve the corrosion resistance of the insulating layer 125.

[0240] Next, the exposed mask layers 145a, 145b, and 145c are removed. The mask layers 145a, 145b, and 145c can be removed by wet etching or dry etching. At this time, it is preferable to use a method that causes as little damage as possible to the EL layers 120R, 120G, and 120B. In particular, it is preferable to use a wet etching method. For example, it is preferable to use wet etching using a tetramethylammonium hydroxide aqueous solution (TMAH), dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof.

[0241] Alternatively, the mask layers 145 a, 145 b, and 145 c may be removed by dissolving them in a solvent such as water or alcohol. Here, various alcohols such as ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin may be used as the alcohol capable of dissolving the mask layers 145 a, 145 b, and 145 c.

[0242] After removing the mask layers 145a, 145b, and 145c, it is preferable to perform drying treatment to remove water contained inside the EL layers 120R, 120G, and 120B and water adsorbed on their surfaces. For example, it is preferable to perform heat treatment in an inert gas atmosphere or a reduced-pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50°C or higher and 200°C or lower, preferably 60°C or higher and 150°C or lower, and more preferably 70°C or higher and 120°C or lower. A reduced-pressure atmosphere is preferable because it enables drying at a lower temperature.

[0243] In this manner, the EL layer 120R, the EL layer 120G, and the EL layer 120B can be separately produced.

[0244] [Formation of EL Layer 121] Subsequently, the EL layer 121 is formed to cover the EL layer 120R, the EL layer 120G, the EL layer 120B, and the insulating layer 125.

[0245] The EL layer 121 can be formed by the same method as the EL film 120Rb, etc. When the EL layer 121 is formed by evaporation, it is preferable to form the EL layer 121 using a shielding mask so that the EL layer 121 is not formed on the connection electrode 101C.

[0246] [Formation of Common Electrode 102] Subsequently, the common electrode 102 is formed to cover the EL layer 121 and the connection electrode 101C (FIG. 9F).

[0247] The common electrode 102 can be formed by a film formation method such as evaporation or sputtering. Alternatively, a film formed by evaporation and a film formed by sputtering may be stacked. In this case, the common electrode 102 is preferably formed so as to encompass the region where the electron injection layer 115 is formed. That is, the common electrode 102 can be configured so that an edge of the electron injection layer 115 overlaps with the common electrode 102. The common electrode 102 is preferably formed using a shielding mask.

[0248] The common electrode 102 is electrically connected to the connection electrode 101C outside the display area.

[0249] [Formation of Protective Layer] Next, a protective layer is formed on the common electrode 102. The inorganic insulating film used for the protective layer is preferably formed by sputtering, PECVD, or ALD. The ALD method is particularly preferred because it has excellent step coverage and is less likely to cause defects such as pinholes. The organic insulating film is preferably formed by inkjet printing, because it can form a uniform film in the desired area.

[0250] Through the above steps, a light-emitting device of one embodiment of the present invention can be manufactured.

[0251] In the above description, the common electrode 102 and the second EL layer 121 are formed to have different top surface shapes; however, they may be formed in the same region.

[0252] In this embodiment, an example in which the light-emitting device described in Embodiments 1 and 2 is used as a lighting device will be described with reference to Fig. 10. Fig. 10B is a top view of the lighting device, and Fig. 10A is a cross-sectional view taken along line e-f in Fig. 10B.

[0253] In the lighting device of this embodiment, an anode 401 is formed on a light-transmitting substrate 400 serving as a support. The anode 401 corresponds to the pixel electrode 101 in Embodiment 1. When light is extracted from the anode 401 side, the anode 401 is formed from a light-transmitting material.

[0254] A pad 412 for supplying a voltage to the cathode 404 is formed on the substrate 400 .

[0255] An EL layer 403 is formed over the anode 401. The EL layer 403 corresponds to the structure of the EL layer 103 in Embodiment Modes 1 and 2. For details of these structures, refer to the descriptions therein.

[0256] A cathode 404 is formed to cover the EL layer 403. The cathode 404 corresponds to the common electrode 102 in Embodiment 1. When light is extracted from the anode 401 side, the cathode 404 is formed of a material with high reflectivity. The cathode 404 is connected to a pad 412 to supply a voltage.

[0257] As described above, the lighting device described in this embodiment has a light-emitting device including the anode 401, the EL layer 403, and the cathode 404. Since the light-emitting device has high emission efficiency, the lighting device in this embodiment can be a lighting device with low power consumption.

[0258] The lighting device is completed by bonding and sealing the substrate 400 on which the light-emitting device having the above structure is formed and the sealing substrate 407 using sealants 405 and 406. Either the sealant 405 or 406 may be used. Also, a desiccant may be mixed into the inner sealant 406 (not shown in FIG. 10B ), which can absorb moisture and improve reliability.

[0259] Furthermore, the pad 412 and a portion of the anode 401 can be extended outside the sealing materials 405 and 406 to serve as an external input terminal. An IC chip 420 equipped with a converter or the like may also be provided thereon.

[0260] As described above, the lighting device described in this embodiment uses the light-emitting device described in Embodiments 1 and 2 as an EL element and has good luminous efficiency, so that the lighting device can have low power consumption.

[0261] This embodiment mode can be freely combined with other embodiment modes.

[0262] Embodiment 6 In this embodiment, examples of electronic devices that include the light-emitting devices described in Embodiments 1 and 2 will be described. The light-emitting devices described in Embodiments 1 and 2 are light-emitting devices with high luminous efficiency (particularly BI). As a result, the electronic devices described in this embodiment can be electronic devices with low power consumption because the light-emitting efficiency of the light-emitting devices is high.

[0263] Examples of electronic devices to which the light-emitting devices are applied include television sets (also called televisions or television receivers), computer monitors, digital cameras, digital video cameras, digital photo frames, mobile phones (also called mobile phones or mobile phone devices), portable game machines, personal digital assistants, sound reproducing devices, large game machines such as pachinko machines, etc. Specific examples of these electronic devices are shown below.

[0264] 11A illustrates an example of a television set. The television set has a display portion 7103 incorporated in a housing 7101. Here, the housing 7101 is supported by a stand 7105. Images can be displayed on the display portion 7103, and the display portion 7103 is configured such that the light-emitting devices described in Embodiments 1 and 2 are arranged in a matrix.

[0265] The television set can be operated using an operation switch provided on the housing 7101 or a separate remote control 7110. A channel or volume can be controlled using operation keys 7109 provided on the remote control 7110, and an image displayed on the display portion 7103 can be controlled. The remote control 7110 may be provided with a display portion 7107 that displays information output from the remote control 7110. Note that the light-emitting devices described in Embodiments 1 and 2 arranged in a matrix can also be applied to the display portion 7107.

[0266] The television device is configured to include a receiver, a modem, etc. The receiver can receive general television broadcasts, and by connecting to a wired or wireless communication network via the modem, it is also possible to perform one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers, etc.) information communication.

[0267] FIG. 11B1 illustrates a computer including a main body 7201, a housing 7202, a display portion 7203, a keyboard 7204, an external connection port 7205, a pointing device 7206, and the like. This computer is manufactured by using the light-emitting devices described in Embodiments 1 and 2 arranged in a matrix for the display portion 7203. The computer in FIG. 11B1 may have a configuration as shown in FIG. 11B2. The computer in FIG. 11B2 is provided with a display portion 7210 instead of the keyboard 7204 and the pointing device 7206. The display portion 7210 is a touch panel type, and input can be performed by operating an input display displayed on the display portion 7210 with a finger or a dedicated pen. The display portion 7210 can display not only an input display but also other images. The display portion 7203 may also be a touch panel. The two screens are connected by a hinge, which can prevent problems such as scratches or breakage of the screens during storage or transportation.

[0268] 11C shows an example of a mobile terminal. The mobile phone includes a display portion 7402 incorporated in a housing 7401, operation buttons 7403, an external connection port 7404, a speaker 7405, a microphone 7406, and the like. Note that the mobile phone has the display portion 7402 in which the light-emitting devices described in Embodiments 1 and 2 are arranged in a matrix.

[0269] 11C can be configured so that information can be input by touching the display portion 7402 with a finger or the like. In this case, operations such as making a call or composing an e-mail can be performed by touching the display portion 7402 with a finger or the like.

[0270] The screen of the display portion 7402 has three main modes. The first is a display mode mainly for displaying images, the second is an input mode mainly for inputting information such as characters, and the third is a display+input mode that combines the display mode and the input mode.

[0271] For example, when making a call or creating an email, the display portion 7402 may be set to a character input mode mainly for inputting characters, and characters displayed on the screen may be input. In this case, it is preferable to display a keyboard or number buttons on most of the screen of the display portion 7402.

[0272] In addition, by providing a detection device having a sensor that detects tilt, such as a gyro or an acceleration sensor, inside the mobile terminal, the orientation of the mobile terminal (portrait or landscape) can be determined and the screen display of the display portion 7402 can be automatically switched.

[0273] The screen mode can be switched by touching the display portion 7402 or by operating the operation buttons 7403 on the housing 7401. The screen mode can also be switched depending on the type of image displayed on the display portion 7402. For example, if the image signal to be displayed on the display portion is moving image data, the display mode is selected, and if it is text data, the input mode is selected.

[0274] In addition, in the input mode, a signal detected by an optical sensor in the display portion 7402 may be detected, and if there is no input by touch operation on the display portion 7402 for a certain period of time, the screen mode may be controlled to switch from the input mode to the display mode.

[0275] The display portion 7402 can also function as an image sensor. For example, personal authentication can be performed by touching the display portion 7402 with a palm or a finger to capture an image of a palm print, a fingerprint, or the like. Furthermore, by using a backlight that emits near-infrared light or a sensing light source that emits near-infrared light for the display portion, finger veins, palm veins, or the like can also be captured.

[0276] As described above, the light-emitting device having the light-emitting device described in Embodiments 1 and 2 has a very wide range of application, and the light-emitting device can be applied to electronic devices in a variety of fields. By using the light-emitting device described in Embodiments 1 and 2, electronic devices with low power consumption can be obtained.

[0277] FIG. 12A is a schematic diagram showing an example of a cleaning robot.

[0278] The cleaning robot 5100 has a display 5101 arranged on its top surface, multiple cameras 5102 arranged on its side, a brush 5103, and an operation button 5104. Although not shown, the cleaning robot 5100 is also provided with tires, a suction port, and the like on its bottom surface. The cleaning robot 5100 is also provided with various other sensors, such as an infrared sensor, an ultrasonic sensor, an acceleration sensor, a piezoelectric sensor, an optical sensor, and a gyro sensor. The cleaning robot 5100 is also provided with wireless communication means.

[0279] The cleaning robot 5100 can move by itself, detect dust 5120, and suck up the dust from a suction port provided on the bottom surface.

[0280] The cleaning robot 5100 can also analyze the image captured by the camera 5102 to determine whether there are any obstacles such as walls, furniture, or steps. If the image analysis detects an object that may become tangled in the brush 5103, such as a wire, the cleaning robot 5100 can stop the rotation of the brush 5103.

[0281] The display 5101 can display the remaining battery level, the amount of dust sucked, etc. The route traveled by the cleaning robot 5100 may be displayed on the display 5101. The display 5101 may also be a touch panel, and an operation button 5104 may be provided on the display 5101.

[0282] The cleaning robot 5100 can communicate with a portable electronic device 5140 such as a smartphone. Images captured by the camera 5102 can be displayed on the portable electronic device 5140. This allows the owner of the cleaning robot 5100 to know the state of the room even when they are away from home. In addition, the display on the display 5101 can be confirmed on the portable electronic device such as a smartphone.

[0283] The light-emitting device of one embodiment of the present invention can be used for the display 5101 .

[0284] The robot 2100 shown in FIG. 12B includes a computing device 2110, an illuminance sensor 2101, a microphone 2102, an upper camera 2103, a speaker 2104, a display 2105, a lower camera 2106, an obstacle sensor 2107, and a movement mechanism 2108.

[0285] The microphone 2102 has a function of detecting the user's voice, environmental sounds, etc. The speaker 2104 has a function of emitting sound. The robot 2100 can communicate with the user using the microphone 2102 and the speaker 2104.

[0286] The display 2105 has a function of displaying various information. The robot 2100 can display information desired by the user on the display 2105. The display 2105 may be equipped with a touch panel. The display 2105 may also be a detachable information terminal, which can be installed in a fixed position on the robot 2100 to enable charging and data transfer.

[0287] The upper camera 2103 and the lower camera 2106 have a function of capturing images of the surroundings of the robot 2100. In addition, the obstacle sensor 2107 can detect the presence or absence of an obstacle in the moving direction when the robot 2100 moves forward using the moving mechanism 2108. The robot 2100 can recognize the surrounding environment and move safely using the upper camera 2103, the lower camera 2106, and the obstacle sensor 2107. The light-emitting device of one embodiment of the present invention can be used for the display 2105.

[0288] 12C is a diagram illustrating an example of a goggle-type display. The goggle-type display includes, for example, a housing 5000, a display unit 5001, a speaker 5003, an LED lamp 5004 (including a power switch or an operation switch), a connection terminal 5006, a sensor 5007 (including a function for measuring force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared ray), a microphone 5008, a second display unit 5002, a support unit 5012, and earphones 5013.

[0289] The light-emitting device of one embodiment of the present invention can be used for the display portion 5001 and the second display portion 5002 .

[0290] 13 shows an example in which the light-emitting device described in Embodiments 1 and 2 is used in a desk lamp, which is a lighting device. The desk lamp shown in FIG.

[0291] 14 shows an example in which the light-emitting devices described in Embodiments 1 and 2 are used as an indoor lighting device 3001. Since the light-emitting devices described in Embodiments 1 and 2 have high emission efficiency, the lighting device can have low power consumption. Furthermore, since the light-emitting devices described in Embodiments 1 and 2 are thin, they can be used as a thin lighting device.

[0292] The light-emitting devices described in Embodiments 1 and 2 can also be mounted on a windshield or dashboard of an automobile. Figure 15 shows one mode in which the light-emitting devices described in Embodiments 1 and 2 are used on a windshield or dashboard of an automobile. Display regions 5200 to 5203 are displays provided using the light-emitting devices described in Embodiments 1 and 2.

[0293] The display region 5200 and the display region 5201 are display devices equipped with the light-emitting devices described in Embodiments 1 and 2, which are provided on the windshield of an automobile. The light-emitting devices described in Embodiments 1 and 2 can be formed into a so-called see-through display device, in which the opposite side can be seen through, by fabricating both the anode and the cathode using light-transmitting electrodes. A see-through display can be installed on the windshield of an automobile without obstructing the view. When a transistor or the like is provided for driving the device, a light-transmitting transistor such as an organic transistor made of an organic semiconductor material or a transistor using an oxide semiconductor is preferably used.

[0294] The display area 5202 is a display device provided on a pillar and incorporating the light-emitting device described in Embodiments 1 and 2. By displaying an image from an imaging means provided on the vehicle body in the display area 5202, the view blocked by the pillar can be complemented. Similarly, the display area 5203 provided on the dashboard can complement the view blocked by the vehicle body by displaying an image from an imaging means provided on the outside of the vehicle, thereby compensating for blind spots and improving safety. By displaying an image to complement the invisible part, safety can be confirmed more naturally and without discomfort.

[0295] The display area 5203 can also provide various other information such as navigation information, speed or RPM, and air conditioning settings. The display items or layout can be changed as needed to suit the user's preferences. This information can also be provided in the display areas 5200 to 5202. The display areas 5200 to 5203 can also be used as lighting devices.

[0296] 16A and 16B show a foldable portable information terminal 5150. The foldable portable information terminal 5150 has a housing 5151, a display area 5152, and a bending portion 5153. Fig. 16A shows the portable information terminal 5150 in an unfolded state. Fig. 16B shows the portable information terminal in a folded state. Although the portable information terminal 5150 has a large display area 5152, it is compact and highly portable when folded.

[0297] The display area 5152 can be folded in half by a bending portion 5153. The bending portion 5153 is composed of an expandable member and multiple support members, and when folding, the expandable member stretches. The bending portion 5153 is folded with a curvature radius of 2 mm or more, preferably 3 mm or more.

[0298] Note that the display region 5152 may be a touch panel (input / output device) equipped with a touch sensor (input device). The light-emitting device of one embodiment of the present invention can be used for the display region 5152.

[0299] 17A to 17C show a foldable portable information terminal 9310. Fig. 17A shows the portable information terminal 9310 in an unfolded state. Fig. 17B shows the portable information terminal 9310 in a state in the process of changing from one of the unfolded state and the folded state to the other. Fig. 17C shows the portable information terminal 9310 in a folded state. The portable information terminal 9310 has excellent portability in a folded state, and has excellent display visibility due to a seamless, wide display area in an unfolded state.

[0300] The display panel 9311 is supported by three housings 9315 connected by hinges 9313. Note that the display panel 9311 may be a touch panel (input / output device) equipped with a touch sensor (input device). Furthermore, the display panel 9311 can be reversibly transformed from an unfolded state to a folded state by bending the two housings 9315 via the hinges 9313. The light-emitting device of one embodiment of the present invention can be used for the display panel 9311.

[0301] At least a part of the configuration examples exemplified in this embodiment and the corresponding drawings can be combined as appropriate with other configuration examples or drawings.

[0302] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0303] In this example, a light-emitting device 1, a light-emitting device 2, and a comparative light-emitting device 1 according to one embodiment of the present invention will be described. The structural formulae of organic compounds used in this example are shown below.

[0304]

[0305] (Method of Fabricating Light-Emitting Device 1) First, a 400 nm silicon oxide film was formed as an insulating film on a silicon substrate by CVD, and then heated at 350°C for 1 hour in a nitrogen atmosphere. Subsequently, 50 nm titanium, 70 nm aluminum, and 6 nm titanium films were formed by sputtering, and the substrate was heated at 300°C for 1 hour to form a reflective electrode. Subsequently, a 10 nm thick indium tin oxide (ITSO) film was formed as a transparent electrode by sputtering. Subsequently, a photomask was created by photolithography, and then the ITSO was patterned by wet etching, and the titanium, aluminum, and titanium stack was patterned by dry etching to form a 3 μm wide pixel electrode 101. The transparent electrode functions as an anode, and together with the reflective electrode, it can be considered as the pixel electrode (anode) 101.

[0306] Next, O ２ Ashing process (substrate temperature 40°C, pressure 0.67 Pa, O ２ After 30 seconds (flow rate 200 sccm, ICP power 2000 W, substrate bias 50 W), the photomask was removed.

[0307] Then, 1 x 10 −４ The substrate was introduced into a vacuum deposition apparatus whose internal pressure had been reduced to about Pa, and was vacuum baked at 170° C. for 60 minutes in a heating chamber within the vacuum deposition apparatus, after which the substrate was allowed to cool for about 30 minutes.

[0308] Next, the substrate on which the pixel electrode 101 was formed was fixed to a substrate holder installed in a vacuum deposition apparatus so that the surface on which the pixel electrode 101 was formed faced downward, and a hole injection layer 111 was formed on the pixel electrode 101 by co-depositing N-(1,1′-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF) represented by the above structural formula (i) and an electron acceptor material (OCHD-003) having a molecular weight of 672 and containing fluorine to a thickness of 10 nm using a deposition method using resistance heating, in a weight ratio of 1:0.03 (= PCBBiF:OCHD-003).

[0309] Next, PCBBiF was evaporated onto the hole injection layer 111 to form a hole transport layer 112 with a thickness of 96 nm.

[0310] Next, an electron blocking layer was formed using N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP) represented by the structural formula (ii) above to a thickness of 10 nm.

[0311] Thereafter, 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth) represented by the structural formula (iii) above and 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b′]bisbenzofuran (abbreviation: 3,10PCA2Nbf(IV)-02) represented by the structural formula (ix) above were co-deposited to a thickness of 25 nm so as to give a weight ratio of 1:0.015 (=αN-βNPAnth:3,10PCA2Nbf(IV)-02), to form a light-emitting layer 113.

[0312] Thereafter, 2-{3-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}dibenzo[f,h]quinoxaline (abbreviation: 2mPCCzPDBq) represented by the above structural formula (v) was evaporated on the light-emitting layer 113 to a thickness of 20 nm to form a hole-blocking layer, and then 2,9-di(2-naphthyl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen) represented by the above structural formula (vi) was evaporated on the light-emitting layer 113 to a thickness of 15 nm to form an electron-transporting layer 114.

[0313] Subsequently, on the light-emitting device 1 on which the electron transport layer 114 had been formed, an aluminum oxide film was formed to a thickness of 30 nm by an ALD (Atomic Layer Deposition) method using trimethylaluminum (abbreviated as TMA) as a precursor and water vapor as an oxidizing agent at 80° C. Next, a tungsten (W) film was formed to a thickness of 50 nm by a sputtering method under an argon gas flow at a pressure of 2.1 Pa and a substrate temperature of 50° C.

[0314] Thereafter, a positive photoresist was applied to a film thickness of 700 nm, and exposure and development were carried out to form a photomask slightly larger than the pixel electrode 101 .

[0315] Next, the formed photomask was used as a mask, and SF was used as an etching gas. ６ The tungsten film was removed by dry etching using O ２ Ashing (substrate temperature 10°C, pressure 5.00 Pa, O ２ The photomask was removed by dry etching (flow rate: 80 sccm, ICP power: 800 W, substrate bias: 10 W, 15 seconds). Thereafter, the aluminum oxide film was removed by dry etching using the tungsten film as a mask, and the hole injection layer 111 to the electron transport layer 114 (first EL layer) were patterned by dry etching using the tungsten film and the aluminum oxide film as a mask.

[0316] Then, the tungsten film is ６The exposed top and side surfaces of the aluminum oxide and the side surfaces of the first EL layer were covered with an aluminum oxide film having a thickness of 10 nm, which was formed by an ALD method at 80° C. using trimethylaluminum (abbreviation: TMA) as a precursor and water vapor as an oxidizing agent.

[0317] Next, a photosensitive organic resin is applied to a film thickness of 400 nm, and is exposed and developed to form an insulating layer having an opening overlapping the pixel electrode 101 with an opening area of ​​7.32 μm ２ It was formed so that ２ After ashing, the substrate was baked at 100° C. under reduced pressure for 1 hour, and then the aluminum oxide film exposed from the openings was removed by wet etching using a developer for 253 seconds.

[0318] Then, 1 x 10 −４ The substrate was placed in a vacuum deposition apparatus whose internal pressure had been reduced to about 1 Pa, and vacuum baking was performed at 70°C for 90 minutes in a heating chamber within the vacuum deposition apparatus. Lithium fluoride (LiF) and ytterbium (Yb) were then co-deposited at a volume ratio of 1:1 and a thickness of 2 nm to form an electron injection layer 115. Finally, silver (Ag) and magnesium (Mg) were co-deposited at a volume ratio of 1:0.1 and a thickness of 25 nm, and a 70 nm film of indium oxide-tin oxide (ITO) was formed to form a cathode (common electrode) 102, thereby producing light-emitting device 1. Note that common electrode 102 is a semi-transmissive / semi-reflective electrode that has the function of reflecting light and the function of transmitting light, and light-emitting device 1 is a top-emission element that extracts light from common electrode 102.

[0319] (Method of manufacturing light-emitting device 2) Light-emitting device 2 was manufactured using almost the same process and layout as light-emitting device 1, but a different photosensitive organic resin was used, and after coating and forming a film, the film was baked at 90°C for 90 seconds, exposed to light, and developed to form an insulating layer having an opening that overlaps with the pixel electrode 101. This is different from light-emitting device 1 in that the film was then irradiated with light from an ultra-high pressure mercury lamp for 86 seconds and baked at 100°C for 600 seconds. This gives the inner side of the insulating layer opening a tapered shape, improving the coverage of the film that is formed subsequently.

[0320] (Method of Manufacturing Comparative Light-Emitting Device 1) Comparative light-emitting device 1 was manufactured by forming up to pixel electrodes 101 in the same manner as light-emitting device 1. −４ The substrate was heated at a substrate temperature of 250° C. for 5 minutes under a reduced pressure of about Pa, and a silicon oxide film was formed to a thickness of 150 nm by sputtering to form an inorganic insulating layer.

[0321] Thereafter, the inorganic insulating layer is dry-etched by photolithography to form an opening having an opening area of ​​7.32 μm 2 that overlaps with the pixel electrode. ２ It was formed so that ２ After ashing, the resist was removed.

[0322] Then, 1 x 10 −４ The substrate was introduced into a vacuum deposition apparatus whose internal pressure had been reduced to about Pa, and was vacuum baked at 170° C. for 60 minutes in a heating chamber within the vacuum deposition apparatus, after which the substrate was allowed to cool for about 30 minutes.

[0323] Next, the hole injection layer 111 to the electron transport layer 114 were formed in the same manner as in the light-emitting device 1. After the electron transport layer was formed, lithium fluoride (LiF) and ytterbium (Yb) were co-deposited at a volume ratio of 1:1 and a thickness of 2 nm to form the electron injection layer 115. Finally, silver (Ag) and magnesium (Mg) were co-deposited at a volume ratio of 1:0.1 and a thickness of 25 nm, and a 70 nm film of indium oxide-tin oxide (ITO) was formed to form the cathode (common electrode) 102, thereby producing the comparative light-emitting device 1. The common electrode 102 is a semi-transparent / semi-reflective electrode that has the function of reflecting and transmitting light, and the comparative light-emitting device 1 is a top-emission element that extracts light from the common electrode 102.

[0324] The stacked structures of the light-emitting device 1, the light-emitting device 2, and the comparative light-emitting device 1 are summarized in the table below.

[0325]

[0326] The light-emitting device 1, the light-emitting device 2, and the comparative light-emitting device 1 were sealed with a glass substrate in a nitrogen atmosphere glove box to prevent exposure to the atmosphere (a sealant was applied to the periphery of the elements, and UV treatment and heat treatment at 80° C. for 1 hour were performed during sealing). After this, the initial characteristics of the light-emitting device 1, the light-emitting device 2, and the comparative light-emitting device 1 were measured.

[0327] The current efficiency-luminance characteristics of light-emitting device 1, light-emitting device 2, and comparative light-emitting device 1 are shown in FIG. 19, the blue index-current density characteristics are shown in FIG. 20, and the emission spectra are shown in FIG.

[0328] Also, 1000 cd / m ２ The main characteristics around 1000 s are shown in the table below. Note that a spectroradiometer (SR-UL1R, manufactured by Topcon Corporation) was used to measure the luminance, CIE chromaticity, and emission spectrum. The measurements of each light-emitting device were carried out at room temperature (in an atmosphere maintained at 23°C).

[0329]

[0330] 19 shows that the current efficiency of light-emitting device 1 and light-emitting device 2 is lower than that of the comparative light-emitting device. However, light-emitting device 1 and light-emitting device 2 have a lower chromaticity y and emit a deeper blue light than comparative light-emitting device 1. Therefore, as shown in FIG. 20, light-emitting device 1 and light-emitting device 2 have a better blue index than comparative light-emitting device 1.

[0331] Here, the blue index (BI) is a value obtained by further dividing the current efficiency (cd / A) by the y chromaticity, and is one of the indices that represent the luminous characteristics of blue light emission. The smaller the y chromaticity, the higher the color purity of blue light emission tends to be. Blue light emission with high color purity can express a wide range of blue even with a small luminance component, and the use of blue light emission with high color purity reduces the required luminance to express blue, thereby achieving a reduction in power consumption. Therefore, the BI, which takes into account the y chromaticity, which is one index of blue purity, is preferably used as a means of expressing the efficiency of blue light emission. It can be said that a light-emitting device with a higher BI has better efficiency as a blue light-emitting device used in a display.

[0332] That is, although light-emitting device 1 and light-emitting device 2 exhibit lower current efficiency than comparative light-emitting device 1, they emit deep blue light and are therefore excellent blue light-emitting devices.

[0333] 21, the peak wavelength of the emission spectrum of Comparative Light-Emitting Device 1 is shifted to a longer wavelength, and the half-width of the peak in the spectrum is also increased. Furthermore, the table shows that the chromaticity y is twice or nearly twice that of Light-Emitting Device 1 and Light-Emitting Device 2.

[0334] As a result, it was found that Light-Emitting Device 1 and Light-Emitting Device 2 were light-emitting devices having superior characteristics as blue light-emitting devices to Comparative Light-Emitting Device 1.

[0335] This result is due to the change in emission wavelength caused by leakage current in the comparative light-emitting device 1. As shown in FIG. 2A , in the comparative light-emitting device 1, the common electrode (cathode) 102 contacts the EL layer over a larger area than the pixel electrode 101. Therefore, current flows not only between the common electrode overlapping the opening in the inorganic insulating film, but also between the common electrode located around it. Since the light excited by such leakage current emits light at a different location than expected, the optical path length of some of the light from inside the light-emitting device to the outside of the device may deviate from the expected wavelength range. Furthermore, light emitted in areas without pixel electrodes 101 does not resonate between the pixel electrode 101 and the common electrode (cathode) 102, and is therefore emitted to the outside as light with a broad spectrum. Furthermore, the angle of the common electrode changes depending on the position due to the unevenness of the inorganic insulating film, making it easier for such light to exit the light-emitting device. For these reasons, light having a longer wavelength than the expected wavelength and light having a broad spectrum width at half maximum are mixed in the light from the comparative light-emitting device 1, causing a change in the emission spectrum.

[0336] On the other hand, in light-emitting devices 1 and 2, the common electrode 102 overlaps the EL layer via an opening in the insulating layer. This makes it difficult for leakage current to flow around the common electrode 102 and prevents light emissions of different wavelengths from mixing, resulting in light emission with good color purity and a light-emitting device with a good blue index. Furthermore, as in light-emitting devices 1 and 2, the hole injection layer 111 through the electron transport layer 114 are etched, and aluminum oxide is formed to a thickness of 40 nm on the top of the EL layer and in the area not covered by the common electrode (electron injection layer), and 10 nm on the side surfaces. This also makes it difficult for leakage current to flow through the EL layer. Furthermore, since it is possible to suppress the emission of light emissions with different optical path lengths to the outside, a light-emitting device with better characteristics can be obtained.

[0337] Next, the relationship between the measurement position, the emission intensity, and the spectral shape of the light-emitting device 2 and the comparative light-emitting device 1 was investigated using a 2D spectroradiometer (SR-5100HM manufactured by Topcon Technohouse Corporation) and the results are shown.

[0338] 1A in Embodiment 1, and the structure of Comparative Light-Emitting Device 1 corresponds to the structure shown in Fig. 26A . The structure shown in Fig. 26A includes an insulating layer 127, a pixel electrode (anode) 101 on the insulating layer 127, an insulating layer 125c covering the side and part of the top surface of the pixel electrode (anode) 101, an EL layer 103 provided so as to cover the pixel electrode (anode) 101 and the insulating layer 125c, an electron injection layer 104 on the EL layer 103, and a common electrode (cathode) 102 provided on the electron injection layer 104.

[0339] The light-emitting device 2 corresponding to the structure shown in FIG. 1A differs significantly from the comparative light-emitting device 1 shown in FIG. 26A in that the insulating layer 125c covering part of the side and top surfaces of the pixel electrode (anode) 101 is not provided, and the EL layer 103 is divided.

[0340] 22 and 23 show the current density of 10 mA / cm ２22 and 23 are the results of measuring the light-emitting device 2 and the comparative light-emitting device 1, which were made to emit light at 2000 kJ / s, with a 2D spectroradiometer. The colors in the images of FIGS. 22 and 23 are related to the light emission intensity.

[0341] 22 (light-emitting device 2), a bright area 1.1 μm wide can be seen in the center of the image, and a slightly less bright area extending 1.6 μm wide outside of that, with the outside area showing almost no light emission. Since the width of the opening provided in the photosensitive organic resin of light-emitting device 2 is 1.14 μm, it can be seen that the 1.1 μm wide area in the center of the image is the area where the pixel electrode and the EL layer are in contact.

[0342] On the other hand, in Figure 23 (Comparative Light-Emitting Device 1), a bright region 1.1 μm wide can be seen in the center of the image, and a slightly less bright region extending 2.2 μm wide outside of that, and it can be seen that the light emission extends further outside that region as well. Since the design value of the width of the opening in the inorganic insulating film of Comparative Light-Emitting Device 1 is 1.14 μm, it can be seen that the 1.1 μm wide region in the center of the image is the region where the pixel electrode and the EL layer are in contact. It can be seen that Comparative Light-Emitting Device 1 emits light over a wider area than Light-Emitting Device 2.

[0343] To investigate the cause of this spread of light emission, several light-emitting devices with different concentrations of acceptor material in the hole injection layer were fabricated based on the structure of comparative light-emitting device 1, and measurements were performed in the same manner. It was found that the light-emitting device with a larger amount of acceptor material and a smaller resistance of the hole injection layer had a wider and brighter light-emitting portion that spread outside the opening. In other words, it is suggested that the spread of light emission outside the opening of comparative light-emitting device 1 is due to light emission around the opening caused by leakage current via the hole injection layer.

[0344] Next, the results of measuring the emission spectrum for each measurement point in each light-emitting device are shown in Figures 24A and 24B and Figures 25A and 25B. Figure 24 shows the emission spectrum for each measurement point in Light-emitting Device 2, and Figure 25 shows the emission spectrum for each measurement point in Comparative Light-emitting Device 1. Each measurement point corresponds to the positions circled as 1 to 5 in Figures 22 and 23.

[0345] In both Figures 24A and 25A, it can be seen that there is little difference in the spectral intensity and spectral shape at measurement points 3, 4, and 5 corresponding to the opening, and that at measurement points 2 and 1, the maximum emission intensity decreases with increasing distance from the opening.

[0346] Figures 24B and 25B show the spectra of Figures 24A and 25A normalized by the maximum emission intensity. Figure 24B shows that the emission spectrum of Light-Emitting Device 2 shows almost no change depending on the measurement position. On the other hand, Figure 25B shows that the shape of the emission spectrum of Comparative Light-Emitting Device 1 does not change significantly at measurement points 3, 4, and 5, which correspond to the aperture. However, at measurement points 2 and 1, which are outside the aperture, peaks appear around 500 nm, indicating a significant change in the spectral shape. This is because light emission occurs at a location different from the expected position due to leakage current through the hole injection layer, resulting in light emission via a cavity with a different optical path length or without passing through the cavity at all.

[0347] As described above, in the comparative light-emitting device 1, the mixed emission of light with different spectral shapes around the opening changes the shape of the emission spectrum throughout the light-emitting device, resulting in a deviation in chromaticity. The required brightness of blue light-emitting devices used in displays is closely related to chromaticity. From the above results, it was found that the mixed emission of long-wavelength light in the peripheral region of the comparative light-emitting device 1 increased the chromaticity y and significantly reduced the BI.

[0348] Here, in order to investigate the mechanism by which the chromaticity and BI of the comparative light-emitting device 1 decreased, cross-sectional scanning transmission electron microscope (STEM) observation was performed on the comparative light-emitting device 1. The cross-sectional STEM image of the comparative light-emitting device 1 and the 2D spectroradiometer measurement image are shown in FIG. 26B .

[0349] In Fig. 26B, region 150 indicates a portion of the 2D spectroradiometer measurement image, and region 152 indicates the results of the cross-sectional STEM image. That is, Fig. 26B is a diagram in which a portion of the 2D spectroradiometer measurement image and the cross-sectional STEM image are combined. Note that region 150 is a diagram in which a portion of the 2D spectroradiometer measurement image shown in Fig. 23 is extracted and enlarged to match the corresponding cross-sectional STEM image. Furthermore, the circled region of measurement point 2 located above region 150 corresponds to measurement point 2 shown in Fig. 23.

[0350] 26B , in the comparative light-emitting device 1, the current flowing through the EL layer 103 around the opening extends to the upper surface of the insulating layer 125c, as indicated by the dashed arrows. This can cause lateral leakage current through the EL layer 103, particularly through the hole injection layer formed below the EL layer 103. As a result, light emission from the EL layer 103 is observed even above the insulating layer 125c, changing the optical path length and the resonant wavelength. This suggests that the light emission from the EL layer 103 in the region overlapping with the insulating layer 125c becomes broader, resulting in the change in the spectral shape shown in FIGS. 25A and 25B .

[0351] On the other hand, it was found that such a change in spectrum does not occur in the light-emitting device of one embodiment of the present invention, and a light-emitting device with a good BI can be provided. Note that the light-emitting device of one embodiment of the present invention has a structure in which an insulating layer (also referred to as a structure or a bank) covering part of the side and top surfaces of the pixel electrode (anode) is not provided, as shown in FIG. 1A . Therefore, it was confirmed that the light-emitting device of one embodiment of the present invention has a sharper emission spectrum and a good BI than a structure in which an insulating layer covering part of the side and top surfaces of the pixel electrode (anode) is provided.

[0352] Note that these phenomena occur in the periphery of the light-emitting device (around the area where the pixel electrode, the EL layer, and the common electrode overlap), and therefore the higher the resolution of the light-emitting device, the more pronounced the phenomenon becomes. For this reason, it can be said that the structure of one embodiment of the present invention is particularly suitable for high-resolution light-emitting devices.

[0353] 100: substrate, 101B: pixel electrode, 101C: connection electrode, 101G: pixel electrode, 101R: pixel electrode, 101: pixel electrode, 102: common electrode, 103: EL layer, 103(1): first EL layer, 103(2): second EL layer, 104: electron injection layer, 107: mask layer, 108: insulating layer, 110B: light-emitting device, 110G: light-emitting device, 110R: light-emitting device, 111: hole injection layer, 112: hole transport layer, 113: light-emitting layer, 114: electron transport layer, 115: electron injection layer, 121: second EL layer, 120B: EL layer, 120Bb: EL film, 120G: EL layer, 120Gb: EL film, 120R: EL layer, 120Rb: EL film, 120: First EL layer, 121: EL layer, 124: insulating layer, 125: insulating layer, 125b: insulating layer, 125c: insulating layer, 126: insulating layer, 126b: insulating layer, 127: insulating layer, 127a: insulating layer, 128: opening, 129: insulating layer, 130: connecting portion, 131: protective layer, 143a: resist mask, 144a: mask film, 145a: mask layer, 145b: mask layer, 145c: mask layer, 146a: protective film, 146b: protective film, 146c: protective film, 147a: protective layer, 150: region, 152: region, 400: substrate, 401: anode, 403: EL layer, 404: cathode, 405: sealing material, 406: sealing material, 407: sealing substrate, 412: pad, 420: IC chip, 450: light emitting device, 601: source line driving circuit, 602: pixel portion, 603: gate line driving circuit, 604: sealing substrate, 605: sealing material, 6 07: Space, 608: Routed wiring, 610: Element substrate, 611: Switching FET, 612: Current control FET, 613: First electrode, 614: Insulator, 616: EL layer, 617: Second electrode, 618: Light-emitting device, 623: FET, 951: Substrate, 952: Electrode, 953: Insulating layer, 954: Partition layer, 955: EL layer, 956: Electrode, 1001: Substrate, 1002: Undercoat insulating film, 1003 : gate insulating film, 1006: gate electrode, 1007: gate electrode, 1008: gate electrode, 1020: first interlayer insulating film, 1021: second interlayer insulating film, 1022: electrode, 1024B: anode, 1024G: anode, 1024R: anode, 1025: partition wall, 1028: EL layer, 1029: cathode, 1031: sealing substrate, 1032: sealing material, 1033: base material, 1034B: colored layer, 1034G: colored layer,1034R: colored layer, 1035: black matrix, 1036: overcoat layer, 1037: third interlayer insulating film, 1040: pixel section, 1041: drive circuit section, 1042: peripheral section, 2001: housing, 2002: light source, 2100: robot, 2101: illuminance sensor, 2102: microphone, 2103: upper camera, 2104: speaker, 2105: display, 2106: lower camera, 2107: obstacle sensor, 2108: moving mechanism, 2110: computing device, 3001: lighting device, 5000: housing, 5001: display unit, 5002: second display unit, 5003: speaker, 5004: LED lamp, 5006: connection terminal, 5007: sensor, 5008: microphone, 5012: support unit, 5013: earphone, 5100: cleaning robot, 5101: display, 5102: camera, 5103: Brush, 5104: Operation button, 5120: Dust, 5140: Portable electronic device, 5150: Portable information terminal, 5151: Housing, 5152: Display area, 5153: Bending portion, 5200: Display area, 5201: Display area, 5202: Display area, 5203: Display area, 7101: Housing, 7103: Display unit, 7105: Stand, 7107: Display unit, 7109: Operation key, 7110: Remote control operation machine, 7201: main body, 7202: housing, 7203: display unit, 7204: keyboard, 7205: external connection port, 7206: pointing device, 7210: display unit, 7401: housing, 7402: display unit, 7403: operation buttons, 7404: external connection port, 7405: speaker, 7406: microphone, 9310: mobile information terminal, 9311: display panel, 9313: hinge, 9315: housing,

Claims

1. a first pixel electrode; a second pixel electrode disposed adjacent to the first pixel electrode; a common electrode; a first EL layer sandwiched between the first pixel electrode and the common electrode; a second EL layer sandwiched between the second pixel electrode and the common electrode; a first insulating layer positioned between the common electrode and the first EL layer, and a second insulating layer having a region in contact with the upper surface and side surfaces of the first insulating layer; the first insulating layer and the second insulating layer positioned between the common electrode and the second EL layer; the first pixel electrode is provided in contact with the upper surface of a third insulating layer; the second pixel electrode is provided in contact with the upper surface of the third insulating layer; the first insulating layer and the second insulating layer have a first opening overlapping the first pixel electrode and a second opening overlapping the second pixel electrode; the first EL layer has a first light-emitting layer; the first light-emitting layer has a first light-emitting substance; the first light-emitting substance exhibits blue light emission; the first EL layer is in contact with the first pixel electrode; the second EL layer is in contact with the second pixel electrode; the first EL layer is in contact with the common electrode through the first opening; the second EL layer is in contact with the common electrode through the second opening; the first insulating layer has a region in contact with the upper surface of the third insulating layer; the second insulating layer has a region positioned on the third insulating layer via the first insulating layer; the first EL layer has a region in contact with the upper surface of the third insulating layer; the second EL layer has a region in contact with the upper surface of the third insulating layer; the first insulating layer has a region in contact with the upper surface and side surfaces of the first EL layer; the first insulating layer has a region in contact with the upper surface and side surfaces of the second EL layer; the first EL layer has a region in contact with the upper surface and side surfaces of the first pixel electrode; the second EL layer has a region in contact with the upper surface and side surfaces of the second pixel electrode; the second insulating layer has a region positioned on the upper surface and side surfaces of the first EL layer via the first insulating layer; the second insulating layer has a region positioned on the upper surface and side surfaces of the second EL layer via the first insulating layer; the second insulating layer has a region positioned on the upper surface and side surfaces of the first pixel electrode via the first insulating layer; The second insulating layer has a region located on the upper surface and side surfaces of the second pixel electrode via the first insulating layer. A light-emitting device.

2. In claim 1, The end portion of the first pixel electrode is covered by the first EL layer, A light-emitting device in which an end portion of the second pixel electrode is covered by the second EL layer.

3. In claim 1, The end portion of the first EL layer is covered by the first insulating layer and the second insulating layer, A light-emitting device in which an end portion of the second EL layer is covered by the first insulating layer and the second insulating layer.

4. A first pixel electrode, A second pixel electrode disposed adjacent to the first pixel electrode, A common electrode, A first EL layer sandwiched between the first pixel electrode and the common electrode, A second EL layer sandwiched between the second pixel electrode and the common electrode, A first insulating layer located between the common electrode and the first EL layer, and a second insulating layer having a region in contact with the upper surface and side surfaces of the first insulating layer, The first insulating layer and the second insulating layer located between the common electrode and the second EL layer, The first pixel electrode is provided in contact with the upper surface of a third insulating layer, The second pixel electrode is provided in contact with the upper surface of the third insulating layer, The first insulating layer and the second insulating layer have a first opening overlapping the first pixel electrode and a second opening overlapping the second pixel electrode, The first EL layer has a third EL layer having a first light-emitting layer and a fourth EL layer located between the third EL layer and the common electrode, The second EL layer has a fifth EL layer having a second light-emitting layer and the fourth EL layer located between the fifth EL layer and the common electrode, The first light-emitting layer has a first light-emitting substance, The first light-emitting substance exhibits blue light emission, The third EL layer is in contact with the first pixel electrode, The fifth EL layer is in contact with the second pixel electrode, The fourth EL layer is in contact with the third EL layer through the first opening, The fourth EL layer is in contact with the fifth EL layer through the second opening, The first insulating layer has a region in contact with the upper surface of the third insulating layer, The second insulating layer has a region located on the third insulating layer via the first insulating layer. The third EL layer has a region in contact with the upper surface of the third insulating layer. The fifth EL layer has a region in contact with the upper surface of the third insulating layer. The first insulating layer has a region in contact with the upper surface and side surfaces of the third EL layer. The first insulating layer has a region in contact with the upper surface and side surfaces of the fifth EL layer. The third EL layer has a region in contact with the upper surface and side surfaces of the first pixel electrode. The fifth EL layer has a region in contact with the upper surface and side surfaces of the second pixel electrode. The second insulating layer has a region located on the upper surface and side surfaces of the third EL layer via the first insulating layer. The second insulating layer has a region located on the upper surface and side surfaces of the fifth EL layer via the first insulating layer. The second insulating layer has a region located on the upper surface and side surfaces of the first pixel electrode via the first insulating layer. The second insulating layer has a region located on the upper surface and side surfaces of the second pixel electrode via the first insulating layer. The light-emitting device.

5. In claim 4, In a region where the first pixel electrode and the second pixel electrode do not overlap, the fourth EL layer is sandwiched in contact with the second insulating layer and the common electrode. The light-emitting device.

6. In claim 4, The end portion of the first pixel electrode is covered by the third EL layer. The end portion of the second pixel electrode is covered by the fifth EL layer. The light-emitting device.

7. In claim 4, The end portion of the third EL layer is covered by the first insulating layer and the second insulating layer. The end portion of the fifth EL layer is covered by the first insulating layer and the second insulating layer. The light-emitting device.

8. In any one of claims 1 to 5, The light-emitting device in which the second insulating layer contains an organic compound.

9. In any one of claims 1 to 5, The first opening and the second opening have a tapered shape on the side surface, The taper angle is less than 90°. The light-emitting device.

10. In any one of claims 1 to 5, The distance between the opposing end portions of the first pixel electrode and the second pixel electrode is 0.5 μm or more and 5 μm or less. The light-emitting device.

11. In any one of claims 1 to 5, The area of the portion where the first pixel electrode, the first EL layer, and the common electrode are in contact and overlap is 5 μm ２ or more and 15 μm ２ or less. The light-emitting device is as described above.

12. In any one of claims 1 to 5, A light-emitting device in which a half-value width of a light emission spectrum exhibited from the first opening of the first EL layer is 20 nm or less.