Light-emitting devices, light-emitting apparatus, electronic equipment and lighting apparatus

Abstract

To provide a light-emitting device with high luminous efficiency and a low driving voltage.SOLUTION: An organic compound has an arylamine structure, and includes a deposition film whose normal light refractive index to light with a wavelength of 458 nm is 1.50 or more and 1.75 or less and whose birefringence Δn to light with a wavelength of 458 nm is 0 or more and 0.008 or less. Alternatively, the deposition film has an orientation order parameter of -0.07 or more and 0.00 or less with respect to the light with a wavelength of an absorption peak at the longest wavelength in an absorption spectrum.SELECTED DRAWING: Figure 1

Description

[Technical Field] 【0001】 One aspect of the present invention relates to organic compounds, light-emitting elements, light-emitting devices, display modules, lighting modules, display devices, light-emitting devices, electronic equipment, lighting devices, and electronic devices. However, one aspect of the present invention is not limited to the above-mentioned technical fields. The technical fields of one aspect of the invention disclosed herein relate to products, methods, or methods of manufacturing. Alternatively, one aspect of the present invention relates to processes, machines, manufacturers, or compositions of matter. More specifically, examples of the technical fields of one aspect of the present invention disclosed herein include semiconductor devices, display devices, liquid crystal display devices, light-emitting devices, lighting devices, energy storage devices, memory devices, imaging devices, methods for driving them, or methods for manufacturing them. [Background technology] 【0002】 The practical application of light-emitting devices (organic EL devices) that utilize electroluminescence (EL) using organic compounds is progressing. The basic structure of these light-emitting devices is an organic compound layer (EL layer) containing a light-emitting material sandwiched between a pair of electrodes. By applying a voltage to this device, carriers are injected, and by utilizing the recombination energy of these carriers, light emission can be obtained from the light-emitting material. 【0003】 Because these light-emitting devices are self-emissive, using them as pixels in a display offers advantages over liquid crystal displays, such as higher visibility and the elimination of the need for a backlight, making them particularly suitable for flat-panel displays. Another major advantage of displays using such light-emitting devices is that they can be manufactured to be thin and lightweight. Furthermore, they are characterized by their extremely fast response speed. 【0004】 Furthermore, since these light-emitting devices can form a continuous, planar light-emitting layer, they can produce light in a planar manner. This is a feature that is difficult to obtain with point light sources such as incandescent bulbs and LEDs (light-emitting diodes), or line light sources such as fluorescent lamps, and therefore has high value as a surface light source that can be applied to lighting and other applications. 【0005】 While displays and lighting devices using light-emitting devices are suitable for various electronic devices, research and development are underway to find light-emitting devices with even better characteristics. 【0006】 One of the problems often raised when discussing organic EL devices is their low light extraction efficiency. A configuration has been proposed to improve light extraction efficiency and enhance external quantum efficiency by forming a layer made of a low refractive index material inside the EL layer (see, for example, Patent Document 1). [Prior art documents] [Patent Documents] 【0007】 [Patent Document 1] U.S. Patent Application Publication No. 2020 / 0176692 [Overview of the project] [Problems that the invention aims to solve] 【0008】 As mentioned above, it is possible to improve the light extraction efficiency by providing a low refractive index layer inside an organic EL device, but there is usually a trade-off between high carrier transport and low refractive index. This is because carrier transport in organic compounds largely depends on the presence of unsaturated bonds, and organic compounds with many unsaturated bonds tend to have a high refractive index. 【0009】 Furthermore, in order to obtain organic compounds with a low refractive index, it is preferable to introduce substituents with low molecular refraction (e.g., saturated hydrocarbon groups, cyclic saturated hydrocarbon groups) into the molecule. However, these substituents may inhibit carrier movement and reduce carrier transportability. 【0010】 When organic EL devices are fabricated using materials with poor carrier transportability, the driving voltage of the EL device becomes high, resulting in high power consumption. Because organic EL devices are thin and lightweight, they are often used to power devices with batteries, making power consumption a very important factor. 【0011】 Therefore, one aspect of the present invention aims to provide an organic compound that has a low refractive index and can suppress an increase in driving voltage even when used in an EL device. 【0012】 Alternatively, one aspect of the present invention aims to provide an organic compound that can be used to create a light-emitting device with high luminous efficiency and low driving voltage. Alternatively, one aspect of the present invention aims to provide a light-emitting device with high luminous efficiency and low driving voltage. Alternatively, one aspect of the present invention aims to provide a light-emitting device, light-emitting apparatus, electronic device, display device, or electronic device with low power consumption. 【0013】 The present invention only needs to solve one of the above-mentioned problems. [Means for solving the problem] 【0014】 One aspect of the present invention is a light-emitting device comprising an anode, a cathode, and an EL layer located between the anode and the cathode, wherein the EL layer comprises a light-emitting layer and a hole transport region, the hole transport region being located between the anode and the light-emitting layer, and the hole transport region comprising an organic compound having an arylamine structure, the ordinary refractive index of the deposited film for light at a wavelength of 458 nm being 1.50 or more and 1.75 or less, and the birefringence Δn of the deposited film for light at a wavelength of 458 nm being 0 or more and 0.008 or less. 【0015】 Alternatively, another aspect of the present invention is a light-emitting device having an anode, a cathode, and an EL layer located between the anode and the cathode, wherein the EL layer has a light-emitting layer and a hole transport region, the hole transport region is located between the anode and the light-emitting layer, and the hole transport region has an organic compound having an arylamine structure, the ordinary refractive index of the deposited film for light at a wavelength of 458 nm is 1.50 or more and 1.75 or less, and the orientation order parameter of the deposited film with respect to the wavelength of the absorption peak located at the longest wavelength of the absorption spectrum is 0.07 or more and 0.00 or less. 【0016】 Alternatively, another aspect of the present invention is a light-emitting device in which, in the above configuration, a group containing a parabiphenyl structure is bonded to at least one of the nitrogen atoms of the amine in the arylamine structure of the organic compound. 【0017】 Alternatively, another aspect of the present invention is a light-emitting device comprising an anode, a cathode, and an EL layer located between the anode and the cathode, wherein the EL layer comprises a light-emitting layer and a hole transport region, the hole transport region located between the anode and the light-emitting layer, and the hole transport region comprises an organic compound having an arylamine structure, the refractive index of the deposited film for light at a wavelength of 458 nm being 1.50 or more and 1.75 or less, and the birefringence Δn of the deposited film for light at a wavelength of 458 nm being 0 or more and 0.04 or less, and the 1,1'-biphenyl-4-yl group being bonded to the nitrogen of the amine. 【0018】 Alternatively, another aspect of the present invention is a light-emitting device comprising an anode, a cathode, and an EL layer located between the anode and the cathode, wherein the EL layer comprises a light-emitting layer and a hole transport region, the hole transport region located between the anode and the light-emitting layer, the hole transport region having an arylamine structure, the ordinary refractive index of the deposited film for light at a wavelength of 458 nm being 1.50 or more and 1.75 or less, and the orientation order parameter of the deposited film for light at the wavelength of the absorption peak located at the longest wavelength of the absorption spectrum being -0.10 or more and 0.00 or less, and the organic compound having a 1,1'-biphenyl-4-yl group bonded to the nitrogen of the amine. 【0019】 Alternatively, another aspect of the present invention is a light-emitting device in which the organic compound has at least one C3 to C8 alkyl group and at least one C6 to C12 cycloalkyl group at at least one of the 2', 3', 4', and 5' positions of the 1,1'-biphenyl-4-yl group. 【0020】 Alternatively, in another aspect of the present invention, the organic compound is a light-emitting device having tert-butyl groups at the 3',5' positions of the 1,1'-biphenyl-4-yl group. 【0021】 Alternatively, another aspect of the present invention is a light-emitting device in which, in the above configuration, the organic compound has hydrogen bonded to the meta carbon in one or more aniline structures contained in the arylamine structure. 【0022】 Alternatively, in another aspect of the present invention, the organic compound is a light-emitting device in which one or more aniline structures contained in the arylamine structure each independently have substituents at the para position. 【0023】 Alternatively, in another aspect of the present invention, the organic compound is a light-emitting device in which one of the benzene rings in the plurality of aniline structures contained in the arylamine structure has a cyclohexyl group at the para position. 【0024】 Alternatively, in another aspect of the present invention, the organic compound is a light-emitting device in which one of the benzene rings in the plurality of aniline structures contained in the arylamine structure has a phenyl group in the ortho position. 【0025】 Alternatively, another aspect of the present invention is a light-emitting device in which the organic compound has a triarylamine structure. 【0026】 Alternatively, another aspect of the present invention is a light-emitting device in which, in the above configuration, the organic compound has a fluorenyl group bonded to the nitrogen of the amine in the arylamine structure. 【0027】 Alternatively, another aspect of the present invention is a light-emitting device in which the organic compound is a monoamine compound. 【0028】 Alternatively, in another aspect of the present invention, the hole transport region comprises a hole injection layer and a hole transport layer, the hole injection layer is located between the anode and the hole transport layer, and the organic compound is contained in the hole transport layer, thereby forming a light-emitting device. 【0029】 Alternatively, in another aspect of the present invention, the hole transport region comprises a hole injection layer and a hole transport layer, the hole injection layer is located between the anode and the hole transport layer, and the organic compound is contained in both the hole injection layer and the hole transport layer in the light-emitting device. 【0030】 Alternatively, another aspect of the present invention is a light-emitting device in which the hole injection layer contains a substance that is acceptor of the organic compound. 【0031】 Alternatively, another aspect of the present invention is a light-emitting device in which the substance exhibiting acceptability is an organic compound. 【0032】 One aspect of the present invention is an organic compound having an arylamine structure, wherein the ordinary refractive index of the deposited film for light at a wavelength of 458 nm is 1.50 or more and 1.75 or less, and the birefringence Δn of the deposited film for light at a wavelength of 458 nm is 0 or more and 0.008 or less. 【0033】 Alternatively, another aspect of the present invention is an organic compound having an arylamine structure, wherein the ordinary refractive index of the deposited film for light at a wavelength of 458 nm is 1.50 or more and 1.75 or less, and the orientation order parameter of the deposited film for light at the wavelength of the absorption peak located at the longest wavelength in the absorption spectrum is -0.07 or more and 0.00 or less. 【0034】 Alternatively, another aspect of the present invention is an organic compound in which, in the above configuration, at least one group containing a parabiphenyl structure is bonded to the nitrogen of the amine in the arylamine structure. 【0035】 Alternatively, another aspect of the present invention is an organic compound having an arylamine structure, wherein the ordinary refractive index of the deposited film for light at a wavelength of 458 nm is 1.50 or more and 1.75 or less, and the birefringence Δn of the deposited film for light at a wavelength of 458 nm is 0 or more and 0.04 or less, and the 1,1'-biphenyl-4-yl group is bonded to the nitrogen of the amine. 【0036】 Alternatively, another aspect of the present invention is an organic compound having an arylamine structure, wherein the ordinary refractive index of the deposited film for light at a wavelength of 458 nm is 1.50 or more and 1.75 or less, and the orientation order parameter of the deposited film for light at the wavelength of the absorption peak located at the longest wavelength in the absorption spectrum is -0.10 or more and 0.00 or less, and a 1,1'-biphenyl-4-yl group is bonded to the nitrogen of the amine. 【0037】 Alternatively, another aspect of the present invention is an organic compound having, in the above configuration, at least one of the 2', 3', 4', and 5' positions of the 1,1'-biphenyl-4-yl group, an alkyl group having 3 to 8 carbon atoms and a cycloalkyl group having 6 to 12 carbon atoms. 【0038】 Alternatively, another aspect of the present invention is an organic compound having a tert-butyl group at the 3',5' position of the 1,1'-biphenyl-4-yl group in the above configuration. 【0039】 Alternatively, another aspect of the present invention is an organic compound in which, in the above configuration, hydrogen is bonded to the meta carbon of a benzene ring in one or more aniline structures contained in the arylamine structure. 【0040】 Alternatively, in another aspect of the present invention, in the above configuration, the benzene rings in one or more aniline structures included in the arylamine structure are each independently organic compounds having substituents at the para position. 【0041】 Alternatively, in another aspect of the present invention, in the above configuration, one of the benzene rings in the plurality of aniline structures contained in the arylamine structure is an organic compound having a cyclohexyl group at the para position. 【0042】 Alternatively, in another aspect of the present invention, in the above configuration, one of the benzene rings in the plurality of aniline structures contained in the arylamine structure is an organic compound having a phenyl group in the ortho position. 【0043】 Alternatively, in another aspect of the present invention, the organic compound in the above configuration is an organic compound having a triarylamine structure. 【0044】 Alternatively, another aspect of the present invention is an organic compound in which a fluorenyl group is bonded to the nitrogen in the above configuration. 【0045】 Alternatively, in another aspect of the present invention, the organic compound in the above configuration is a monoamine compound. 【0046】 Alternatively, another aspect of the present invention is a hole transport layer material comprising the organic compound described in any of the above. 【0047】 Alternatively, another aspect of the present invention is a hole injection layer material comprising any of the organic compounds described above. 【0048】 Alternatively, another aspect of the present invention is a light-emitting device comprising the organic compound described in any of the above. 【0049】 Alternatively, another aspect of the present invention is an electronic device having the light-emitting device described in any of the above, and a sensor, an operating button, a speaker, or a microphone. 【0050】 Alternatively, another aspect of the present invention is a light-emitting device having the light-emitting device described in any of the above descriptions, a transistor, or a substrate. 【0051】 Alternatively, another aspect of the present invention is a lighting device having a light-emitting device as described above and a housing. 【0052】 In this specification, the term "light-emitting device" includes image display devices that use light-emitting devices. Furthermore, modules to which connectors, such as anisotropic conductive films or TCPs (Tape Carrier Packages), are attached to light-emitting devices, modules to which printed circuit boards are provided at the end of TCPs, or modules to which ICs (integrated circuits) are directly mounted using the COG (Chip On Glass) method may also be included as light-emitting devices. Additionally, lighting fixtures and the like may have light-emitting devices. [Effects of the Invention] 【0053】 In one aspect of the present invention, an organic compound can be provided that enables the fabrication of a light-emitting device with high luminous efficiency and low driving voltage. Alternatively, in one aspect of the present invention, a light-emitting device with high luminous efficiency and low driving voltage can be provided. Alternatively, in one aspect of the present invention, any of the following can be provided: a light-emitting device, a light-emitting apparatus, an electronic device, a display device, or an electronic device with low power consumption. 【0054】 Furthermore, the description of these effects does not preclude the existence of other effects. Moreover, one aspect of the present invention does not necessarily have to possess all of these effects. Other effects will naturally become apparent from the description in the specification, drawings, and claims, and it is possible to extract other effects from the description in the specification, drawings, and claims. [Brief explanation of the drawing] 【0055】 [Figure 1] Figure 1 is a graph showing the difference in driving voltage (ΔV) between a conventional light-emitting device and a light-emitting device using an organic compound with a low refractive index, with respect to the birefringence Δn of the deposited film of the organic compound. [Figure 2] Figure 2 is a graph showing the difference (ΔV) in driving voltage between a conventional light-emitting device and a light-emitting device using an organic compound with a low refractive index, with respect to the orientation order parameter S of the deposited film of the organic compound. [Figure 3] Figures 3(A), 3(B), and 3(C) are schematic diagrams of the light-emitting device. [Figure 4] Figures 4(A) and 4(B) are diagrams representing an active matrix type light-emitting device. [Figure 5] Figures 5(A) and 5(B) are diagrams representing an active matrix type light-emitting device. [Figure 6] Figure 6 is a diagram representing an active matrix type light-emitting device. [Figure 7] Figures 7(A) and 7(B) are diagrams representing passive matrix type light-emitting devices. [Figure 8] Figures 8(A) and 8(B) are diagrams representing lighting devices. [Figure 9] Figures 9(A), 9(B1), 9(B2), and 9(C) are diagrams representing electronic devices. [Figure 10] Figures 10(A), 10(B), and 10(C) are diagrams representing electronic devices. [Figure 11] Figure 11 is a diagram representing a lighting device. [Figure 12]Figure 12 is a diagram representing a lighting device. [Figure 13] Figure 13 is a diagram representing an in-vehicle display device and lighting system. [Figure 14] Figures 14(A) and 14(B) are diagrams representing electronic devices. [Figure 15] Figures 15(A), 15(B), and 15(C) are diagrams representing electronic devices. [Figure 16] Figure 16 is a graph showing the difference (ΔV) in driving voltage between light-emitting devices 1 to 7 and conventional light-emitting devices, with respect to the birefringence Δn of the deposited film of the low refractive index organic compound possessed by each light-emitting device. [Figure 17] Figure 17 is a graph showing the difference (ΔV) in driving voltage between light-emitting devices 1 to 7 and conventional light-emitting devices with respect to the orientation order parameter S of the deposited film of the low refractive index organic compound possessed by the light-emitting device. [Figure 18] Figure 18 shows the luminance-current density characteristics of light-emitting devices 1-2, 2-4, 3-3, and comparative light-emitting device 10. [Figure 19] Figure 19 shows the luminance-voltage characteristics of light-emitting devices 1-2, 2-4, 3-3, and comparative light-emitting device 10. [Figure 20] Figure 20 shows the current efficiency-luminance characteristics of light-emitting devices 1-2, 2-4, 3-3, and comparative light-emitting device 10. [Figure 21] Figure 21 shows the current density-voltage characteristics of light-emitting devices 1-2, 2-4, 3-3, and comparative light-emitting device 10. [Figure 22] Figure 22 shows the power efficiency-luminance characteristics of light-emitting devices 1-2, 2-4, 3-3, and comparative light-emitting device 10. [Figure 23] Figure 23 shows the external quantum efficiency-luminance characteristics of light-emitting devices 1-2, 2-4, 3-3, and comparative light-emitting device 10. [Figure 24]Figure 24 shows the emission spectra of light-emitting devices 1-2, 2-4, 3-3, and comparative light-emitting device 10. [Figure 25] Figure 25 is a graph showing the change in brightness with respect to the operating time of light-emitting devices 1-2, 2-4, 3-3, and comparative light-emitting device 10. [Figure 26] Figure 26 shows the absorption spectrum of the low-n HTM used. [Figure 27] Figure 27 shows the current density-voltage characteristics of a measurement element using mmtBuBioFBi with only holes as carriers. [Figure 28] Figure 28 shows the hole mobility of mmtBuBioFBi. [Figure 29] Figure 29 shows the luminance-current density characteristics of the light-emitting device 20 and the comparison light-emitting device 20. [Figure 30] Figure 30 shows the luminance-voltage characteristics of the light-emitting device 20 and the comparison light-emitting device 20. [Figure 31] Figure 31 shows the current efficiency-luminance characteristics of the light-emitting device 20 and the comparative light-emitting device 20. [Figure 32] Figure 32 shows the current density-voltage characteristics of the light-emitting device 20 and the comparison light-emitting device 20. [Figure 33] Figure 33 shows the blue index-luminance characteristics of the light-emitting device 20 and the comparison light-emitting device 20. [Figure 34] Figure 34 shows the emission spectra of the light-emitting device 20 and the comparison light-emitting device 20. [Figure 35] Figure 35 shows the normalized luminance-time variation characteristics of the light-emitting device 20 and the comparative light-emitting device 20. [Figure 36] Figure 36 shows the luminance-current density characteristics of light-emitting device 30, light-emitting device 31, and comparative light-emitting device 30 and comparative light-emitting device 31. [Figure 37]Figure 37 shows the luminance-voltage characteristics of light-emitting device 30, light-emitting device 31, and reference light-emitting device 30 and reference light-emitting device 31. [Figure 38] Figure 38 shows the current efficiency-luminance characteristics of light-emitting device 30, light-emitting device 31, and comparative light-emitting device 30 and comparative light-emitting device 31. [Figure 39] Figure 39 shows the current density-voltage characteristics of light-emitting device 30, light-emitting device 31, and comparison light-emitting device 30 and comparison light-emitting device 31. [Figure 40] Figure 40 shows the blue index-luminance characteristics of light-emitting device 30, light-emitting device 31, and reference light-emitting device 30 and reference light-emitting device 31. [Figure 41] Figure 41 shows the emission spectra of light-emitting device 30, light-emitting device 31, reference light-emitting device 30, and reference light-emitting device 31. [Figure 42] Figure 42 shows the normalized luminance-time variation characteristics of light-emitting device 30, light-emitting device 31, and comparative light-emitting device 30 and comparative light-emitting device 31. [Modes for carrying out the invention] 【0056】 The embodiments of the present invention will be described in detail below with reference to the drawings. However, it will be readily apparent to those skilled in the art that the present invention is not limited to the following description, and that its form and details can be modified in various ways without departing from the spirit and scope of the present invention. Accordingly, the present invention shall not be interpreted as being limited to the contents of the embodiments shown below. 【0057】 (Embodiment 1) When light is incident perpendicular to the optical axis of a material, light from a vibration plane perpendicular to the optical axis is called ordinary light (or ordinary rays), and light from a vibration plane parallel to the optical axis is called extraordinary light (or extraordinary rays). The refractive index of ordinary light is n. o , abnormal light refractive index n e These are the refractive indices corresponding to the ordinary and extraordinary light of the material being measured, respectively. Ordinary refractive index n o and the abnormal refractive index n eBy performing anisotropy analysis, each can be calculated. The birefringence Δn is the ordinary light refractive index n o and the extraordinary light refractive index n e The difference between them (Δn = |n o - n e |). When anisotropy occurs in the material, the refractive index n o for ordinary light and the refractive index n e for extraordinary light may be different, and the birefringence Δn represents this difference. 【0058】 The organic compound of one aspect of the present invention has an arylamine structure, and the ordinary light refractive index of the vapor-deposited film with respect to light with a wavelength of 458 nm is 1.50 or more and 1.75 or less, and the birefringence Δn of the vapor-deposited film with respect to light with a wavelength of 458 nm is 0 or more and 0.008 or less. 【0059】 Fig. 1 shows a graph representing the relationship between the birefringence Δn of the organic compound used in the hole transport region (hole injection layer, hole transport layer) and the driving voltage of the light-emitting device. 【0060】 In Fig. 1, the vertical axis represents the difference (ΔV, at 1 mA) between the driving voltage of the light-emitting device using an organic compound with a low refractive index in the hole transport region and the driving voltage of the reference light-emitting device. In the hole transport region of the reference light-emitting device, a material with a refractive index of about 1.8 to 1.9, which is usually used in light-emitting devices, is used. Note that the device structure is substantially the same except for the organic compound. Also, in Fig. 1, the horizontal axis represents the birefringence Δn of the organic compound used in the hole transport region of the above light-emitting device. In Fig. 1, except for the cross plots, the plots of the light-emitting devices using the same organic compound are represented by the same symbol. 【0061】 As described above, a light-emitting device containing an organic compound with a low refractive index may have a higher driving voltage than a light-emitting device using an organic compound showing a normal refractive index because it has a group with a small molecular refraction. In fact, in Fig. 1, many light-emitting devices also have a driving voltage higher than 0.3 V and higher than that of the reference light-emitting device that does not use a low refractive index material. 【0062】 However, as shown in Figure 1, organic EL devices using materials with a very small birefringence Δn of 0.008 or less at a wavelength of 458 nm showed significantly lower driving voltages compared to devices using materials with a large birefringence Δn. This suggests that by using organic compounds with a low refractive index of the deposited film (ordinary refractive index of the deposited film for light at a wavelength of 458 nm is between 1.50 and 1.75) and a small birefringence Δn of the deposited film (birefringence Δn of the deposited film for light at a wavelength of 458 nm is between 0 and 0.008), it is possible to fabricate light-emitting devices with a low driving voltage and a low refractive index layer within the EL layer, resulting in high external quantum efficiency. 【0063】 Furthermore, a small birefringence Δn means that there is little difference in the optical effect the material has on ordinary light and extraordinary light. Therefore, Figure 2 shows a graph illustrating the relationship between the orientation order parameter S of the organic compound and the difference in driving voltage (ΔV, at 1mA) between a light-emitting device using a conventional material and a light-emitting device using an organic compound with a small refractive index in a similar device structure. The orientation order parameter S is given by S = (k e -k o ) / (k e +2k o )(However, k o k represents the extinction coefficient for light perpendicular to the optical axis, e The orientation order parameter S is expressed as (where S represents the extinction coefficient for light parallel to the optical axis) and is used as an index to represent the orientation state of a material. The orientation order parameter S takes values ​​in the range of -0.5 to +1, with -0.5 for perfectly horizontal orientation to the substrate, +1 for perfectly perpendicular orientation to the substrate, and 0 for random orientation. 【0064】 In Figures 1 and 2, the results for light-emitting devices using the same organic compound are represented by the same symbol. From Figure 2, materials with a small birefringence Δn tended to have a small orientation order parameter S, and a correlation with ΔV was observed. Specifically, by using organic compounds in which the refractive index of the deposited film is low (the ordinary refractive index of the deposited film for light at a wavelength of 458 nm is between 1.50 and 1.75) and the orientation order parameter S of the deposited film for light at the wavelength of the absorption peak located at the longest wavelength in the absorption spectrum is between -0.07 and 0.00, it becomes possible to fabricate light-emitting devices with a low driving voltage and a layer with a low refractive index inside the EL layer, and with high external quantum efficiency. This value is close to 0, indicating that it is possible to lower the driving voltage of the light-emitting device by using materials with orientation close to random orientation. 【0065】 The organic compound used in the light-emitting device, having a vapor-deposited film with a paraphotometric refractive index of 1.50 to 1.75 for light at a wavelength of 458 nm, preferably has an amine structure because it provides good carrier transport properties. The amine structure is even more preferably an arylamine structure because it further improves carrier transport properties. Furthermore, the arylamine structure is even more preferably a triarylamine structure for the same reason. 【0066】 Furthermore, it is preferable that the nitrogen in the amine structure has one or more groups containing a biphenyl structure bonded to it. Organic compounds to which a group containing an ortho-biphenyl structure is bonded as the biphenyl structure are preferred because they have good carrier transport properties. Organic compounds to which a group having a fluorene structure is bonded as the biphenyl structure are also preferred because they have good carrier transport properties. Furthermore, organic compounds to which a group containing a para-biphenyl structure is bonded as the biphenyl structure are preferred because they have good carrier transport properties and an improved glass transition temperature (Tg). 【0067】 Furthermore, an organic compound in which a 1,1'-biphenyl-4-yl group is bonded to the nitrogen in the above amine structure is a preferred configuration because it allows for the creation of a light-emitting device with a low driving voltage if the birefringence Δn of the deposited film for light at a wavelength of 458 nm is in the range of 0.008 to 0.04, or if the orientation order parameter S of the deposited film for light at the wavelength of the absorption peak located at the longest wavelength in the absorption spectrum is in the range of -0.10 to 0.00. 【0068】 In other words, an organic compound having an arylamine structure, wherein the ordinary refractive index of the deposited film for light at a wavelength of 458 nm is 1.50 or more and 1.75 or less, and the birefringence Δn of the deposited film for light at a wavelength of 458 nm is 0 or more and 0.04 or less, and the organic compound has a 1,1'-biphenyl-4-yl group, or an organic compound having an arylamine structure, wherein the ordinary refractive index of the deposited film for light at a wavelength of 458 nm is 1.50 or more and 1.75 or less, and the orientation order parameter S of the deposited film for light at the wavelength of the absorption peak located at the longest wavelength in the absorption spectrum is -0.10 or more and 0.00 or less, and the organic compound has a 1,1'-biphenyl-4-yl group is preferred. A light-emitting device using such an organic compound can be made into a device with high external quantum efficiency, low driving voltage, and low power consumption. 【0069】 Furthermore, to achieve a low refractive index, it is preferable that the organic compound has multiple saturated hydrocarbon groups and / or cyclic saturated hydrocarbon groups bonded to it. The saturated hydrocarbon groups and cyclic saturated hydrocarbon groups are preferably groups having 1 to 12 carbon atoms, more preferably alkyl groups having 3 to 8 carbon atoms and cycloalkyl groups having 6 to 12 carbon atoms, and even more preferably tert-butyl groups and cyclohexyl groups. However, it is preferable that these groups are not bonded to the meta position of the benzene ring directly bonded to the nitrogen of the amine skeleton, as this would greatly hinder carrier transport. In other words, it is preferable that the saturated hydrocarbon groups and cyclic saturated hydrocarbon groups are not bonded to the meta position of the aniline structure. 【0070】 Furthermore, it is preferable that the 1,1'-biphenyl-4-yl group described above has at least one of its 2', 3', 4', or 5' positions bonded to an alkyl group having 3 to 8 carbon atoms and a cycloalkyl group having 6 to 12 carbon atoms, and it is particularly preferable that a tert-butyl group is bonded to the 3' and 5' positions. 【0071】 Furthermore, while all carbon atoms in the saturated hydrocarbon group and cyclic saturated hydrocarbon group are bonded using sp3 hybrid orbitals, it is preferable that the proportion of carbon atoms bonded using sp3 hybrid orbitals relative to the total number of carbon atoms in the molecule is between 23% and 55%. 【0072】 Also, 1 It is preferable that the organic compound, when measured by 1H-NMR, has an integrated signal of less than 4 ppm that exceeds the integrated signal of 4 ppm or more. 【0073】 Furthermore, it is preferable that the above organic compound has at least one group containing a fluorene structure, as this improves carrier transport properties. 【0074】 Examples of organic compounds having hole transport properties as described above include those with the following general formula (G h1 1)~(G h1 4), general formula (G h2 1)~(G h2 Examples of organic compounds having a structure like that described in 3) are listed. These organic compounds have a normal refractive index of the deposited film for light at a wavelength of 458 nm that is between 1.50 and 1.75. From these, organic compounds can be selected and used in which the birefringence Δn for light at a wavelength of 458 nm or the orientation order parameter S for light at the wavelength of the absorption peak located at the longest wavelength in the absorption spectrum is within the range described above. 【0075】 [ka] 【0076】 The above general formula (Gh1 1) In Ar 1 Ar 2 Each of these independently represents a benzene ring or a substituent consisting of two or three benzene rings bonded to each other. However, Ar 1 Ar 2 One or both of them have one or more C1- to C12 hydrocarbon groups in which carbon atoms form bonds only in sp3 hybrid orbitals, and Ar 1 and Ar 2 The total number of carbon atoms in all the hydrocarbon groups bonded to it is 8 or more, and Ar 1 and Ar 2 The total number of carbon atoms in all the hydrocarbon groups bonded to either one of the above is 6 or more. 1 or Ar 2 If multiple linear alkyl groups having 1 or 2 carbon atoms are bonded to the hydrocarbon group, these linear alkyl groups may be bonded to each other to form a ring. 【0077】 [ka] 【0078】 The above general formula (G h1 2) In this case, m and r each independently represent 1 or 2, and m+r is 2 or 3. Also, t represents an integer from 0 to 4, and is preferably 0. 5 represents any hydrocarbon group having 1 to 3 carbon atoms, and if t is an integer from 2 to 4, multiple R 5 Each of them may be the same or different, and R 5 If there are multiple bases, adjacent bases (R 5 The two groups may be bonded to each other to form a ring. Note that when m is 2, the types of substituents, the number of substituents, and the positions of the bonds on the two phenylene groups may be the same or different, and when r is 2, the types of substituents, the number of substituents, and the positions of the bonds on the two phenyl groups may be the same or different. 【0079】 [ka] 【0080】 The above general formula (G h1 2) and (G h1 In 3), n and p each independently represent 1 or 2, and n+p is 2 or 3. Also, s represents an integer from 0 to 4, and is preferably 0. 4 represents any hydrocarbon group having 1 to 3 carbon atoms, and if s is an integer from 2 to 4, then multiple R 4 Each of them may be the same or different, and R 4 If there are multiple bases, adjacent bases (R 4 The two phenylene groups may be bonded to each other to form a ring. When n is 2, the types of substituents, the number of substituents, and the positions of the bonds on the two phenylene groups may be the same or different, and when p is 2, the types of substituents, the number of substituents, and the positions of the bonds on the two phenyl groups may be the same or different. 【0081】 [ka] 【0082】 The above general formula (G h1 2)~(G h1 In 4), R 10 ~R 14 and R 20 ~R 24 Each of these independently represents a hydrocarbon group with 1 to 12 carbon atoms, in which hydrogen or carbon atoms form bonds solely through sp3 hybrid orbitals. 10 ~R 14 At least 3 of and R 20 ~R 24 It is preferable that at least 3 of them are hydrogen. As hydrocarbon groups having 1 to 12 carbon atoms in which carbon atoms form bonds only with sp3 hybrid orbitals, tert-butyl groups and cyclohexyl groups are preferred. However, R 10 ~R 14 and R 20 ~R 24 The total amount of carbon contained in is 8 or more, and R10 ~R 14 or R 20 ~R 24 The total amount of carbon in either one of the two is 6 or more. 10 ~R 14 and R 20 ~R 24 In this case, adjacent groups may be bonded to each other to form a ring. 【0083】 Also, the above general formula (G h1 1)~(G h1 In 4), each u independently represents an integer from 0 to 4, and is preferably 0. If u is an integer from 2 to 4, multiple R 3 These can be the same or different. Also, R 1 , R 2 and R 3 Each of these independently represents an alkyl group having 1 to 4 carbon atoms, R 1 and R 2 They may be joined to each other to form a ring. 【0084】 Furthermore, one of the materials having hole transport properties is the following (G h2 1)~(G h2 3) Preferably, the arylamine compound has at least one aromatic group, and the aromatic group has a first to third benzene ring and at least three alkyl groups. The first to third benzene rings are bonded in this order, and the first benzene ring is directly bonded to the nitrogen of the amine. 【0085】 Furthermore, the first benzene ring may have substituted or unsubstituted phenyl groups, and it is preferable that it has unsubstituted phenyl groups. Also, the second or third benzene ring may have alkyl-substituted phenyl groups. 【0086】 Furthermore, of the first to third benzene rings, two or more benzene rings, preferably all of them, do not have hydrogen directly bonded to the carbon atoms at positions 1 and 3. Instead, hydrogen is bonded to one of the first to third benzene rings, the alkyl-substituted phenyl group, the three alkyl groups, or the nitrogen atom of the amine. 【0087】 Furthermore, the arylamine compound preferably has a second aromatic group. The second aromatic group is preferably an unsubstituted monocycle or a substituted or unsubstituted fused ring of three or fewer rings, and more preferably a substituted or unsubstituted fused ring of three or fewer rings, wherein the fused ring has 6 to 13 carbon atoms forming the ring, and even more preferably a group having a fluorene ring. Dimethylfluorenyl is preferred as the second aromatic group. 【0088】 Furthermore, it is preferable that the above arylamine compound further has a third aromatic group. The third aromatic group is a group having one to three substituted or unsubstituted benzene rings. 【0089】 The at least three alkyl groups mentioned above, and the alkyl group substituted for the phenyl group, are preferably chain alkyl groups having 2 to 5 carbon atoms. In particular, branched chain alkyl groups having 3 to 5 carbon atoms are preferred, and t-butyl groups are even more preferred. 【0090】 [ka] 【0091】 Note that the above general formula (G h2 1) In Ar 101 represents a substituted or unsubstituted benzene ring, or a substituent consisting of two or three substituted or unsubstituted benzene rings bonded to each other. 【0092】 [ka] 【0093】 In addition, in the above general formula (G h2 2), x and y each independently represent 1 or 2, and x + y is 2 or 3. Also, R 109 represents an alkyl group having 1 to 4 carbon atoms, and w represents an integer from 0 to 4. Also, R 141 to R 145 each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and a cycloalkyl group having 5 to 12 carbon atoms. When w is 2 or more, the plurality of R 109 may be the same or different from each other. Also, when x is 2, the types, numbers, and bonding positions of the substituents of the two phenylene groups may be the same or different. Also, when y is 2, the types and numbers of the substituents of the phenyl group having two R 141 to R 145 may be the same or different. 【0094】 【Chemical formula】 【0095】 In addition, in the above general formula (G h2 3), R 101 to R 105 each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 6 to 12 carbon atoms, and a substituted or unsubstituted phenyl group. 【0096】 Also, in the above general formulas (G h2 1) to (G h2 3), R 106 , R 107 and R 108 each independently represent an alkyl group having 1 to 4 carbon atoms, and v represents an integer from 0 to 4. When v is 2 or more, the plurality of R 108 may be the same or different from each other. Also, R 111 to R 115One is a substituent represented by the above general formula (g1), and the rest each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted phenyl group. Further, in the above general formula (g1), R 121 to R 125 One is a substituent represented by the above general formula (g2), and the rest each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and a phenyl group substituted with an alkyl group having 1 to 6 carbon atoms. Further, in the above general formula (g2), R 131 to R 135 each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and a phenyl group substituted with an alkyl group having 1 to 6 carbon atoms. Note that among R 111 to R 115 , R 121 to R 125 and R 131 to R 135 , at least 3 or more are alkyl groups having 1 to 6 carbon atoms, the substituted or unsubstituted phenyl group in R 111 to R 115 is 1 or less, and the phenyl group substituted with an alkyl group having 1 to 6 carbon atoms in R 121 to R 125 and R 131 to R 135 is 1 or less. Also, among the three combinations of R 112 and R 114 , R 122 and R 124 , and R 132 and R 134 , in at least two of the three combinations, at least one R is other than hydrogen. 【0097】 Note that in this specification, when "substituted or unsubstituted" or "substituted or unsubstituted" is described, when the group to which they are attached has a substituent, as the substituent, an alkyl group having 1 to 6 carbon atoms and a cycloalkyl group having 5 to 12 carbon atoms can be used. 【0098】 As described above, the organic compound according to one aspect of the present invention has a low refractive index, yet when used in a light-emitting device, it exhibits a small increase in driving voltage. Therefore, a light-emitting device using the organic compound according to one aspect of the present invention can be made into a light-emitting device with high external quantum efficiency and low driving voltage. 【0099】 (Embodiment 2) 【0100】 Figure 3(A) shows a diagram representing a light-emitting device according to one embodiment of the present invention. The light-emitting device according to one embodiment of the present invention has a first electrode 101, a second electrode 102, and an EL layer 103, and the EL layer uses the organic compound shown in Embodiment 1. 【0101】 The EL layer 103 has an emissive layer 113, and may have one or both of a hole injection layer 111 and a hole transport layer 112. The emissive layer 113 contains an emissive material, and the light-emitting device according to one embodiment of the present invention obtains light from the emissive material. The emissive layer 113 may also contain a host material and other materials. The organic compound according to one embodiment of the present invention shown in Embodiment 1 may be contained in the emissive layer 113, in the hole transport layer 112, in the hole injection layer, or in any of these. 【0102】 In addition to these, Figure 3(A) also shows an electron transport layer 114 and an electron injection layer 115, but the configuration of the light-emitting device is not limited to these. 【0103】 Because the organic compound has good hole transport properties, it is effective to use it in the hole transport layer 112. Furthermore, the organic compound according to one embodiment of the present invention can be used as a hole injection layer 111 using a film obtained by mixing the organic compound with an acceptor material. 【0104】 Furthermore, the organic compound according to one embodiment of the present invention can also be used as a host material. Alternatively, the organic compound may be co-deposited with an electron transport material within the light-emitting layer to form an excitation complex between the electron transport material and the hole transport material. By forming an excitation complex with an appropriate emission wavelength, it is possible to achieve effective energy transfer to the light-emitting material and provide a light-emitting device with high efficiency and a good lifespan. 【0105】 Since the organic compound according to one embodiment of the present invention is an organic compound with a low refractive index, by using it inside the EL layer, a light-emitting device with good external quantum efficiency can be obtained. Furthermore, when the organic compound according to one embodiment of the present invention is used in a light-emitting device, it is possible to suppress the increase in driving voltage compared to when other low refractive index organic compounds are used. Therefore, a light-emitting device using the organic compound according to one embodiment of the present invention can be a light-emitting device with high external quantum efficiency and low driving voltage. 【0106】 Next, a detailed structure and examples of materials for the light-emitting device described above will be explained. In one embodiment of the present invention, as described above, the light-emitting device has an EL layer 103 consisting of multiple layers between a pair of electrodes, a first electrode 101 and a second electrode 102, and any portion of the EL layer 103 contains the organic compound disclosed in Embodiment 1. 【0107】 The first electrode 101 is preferably formed using a metal, alloy, conductive compound, or mixture thereof with a large work function (specifically, 4.0 eV or more). Specifically, examples include indium tin oxide (ITO), indium tin oxide containing silicon or silicon oxide, indium zinc oxide, and indium oxide (IWZO) containing tungsten oxide and zinc oxide. These conductive metal oxide films are usually deposited by sputtering, but they may also be fabricated using methods such as the sol-gel method. As an example of a fabrication method, indium zinc oxide can be formed by sputtering using a target containing 1 to 20 wt% zinc oxide relative to indium oxide. Indium oxide (IWZO) containing tungsten oxide and zinc oxide 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 include gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), or nitrides of metallic materials (e.g., titanium nitride). Graphene can also be used. Furthermore, by using the composite material described later in the layer in contact with the first electrode 101 in the EL layer 103, the electrode material can be selected regardless of the work function. 【0108】 The EL layer 103 preferably has a multilayer structure, but there are no particular limitations on the multilayer structure, and various layer structures such as hole injection layers, hole transport layers, electron transport layers, electron injection layers, carrier block layers, exciton block layers, and charge generation layers can be applied. In this embodiment, two types of configurations will be described: one having a hole injection layer 111, a hole transport layer 112, and an emissive layer 113, in addition to an electron transport layer 114 and an electron injection layer 115, as shown in Figure 3(A); and another having a hole injection layer 111, a hole transport layer 112, an emissive layer 113, in addition to an electron transport layer 114, an electron injection layer 115, and a charge generation layer 116, as shown in Figure 3(B). The materials constituting each layer are specifically described below. 【0109】 The hole injection layer 111 is a layer containing an acceptor substance. Both organic and inorganic compounds can be used as the acceptor substance. 【0110】 Examples of substances with acceptor properties include compounds having electron-withdrawing groups (halogen groups, cyano groups, etc.), such as 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviated as F4-TCNQ), chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexazatriphenylene (abbreviated as HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviated as F6-TCNNQ), and 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyrene-2-ylidene)malononitrile. In particular, compounds in which an electron-withdrawing group is bonded to a condensed aromatic ring having multiple heteroatoms, such as HAT-CN, are thermally stable and preferred. Furthermore, radialene derivatives having an electron-withdrawing group (especially halogen groups such as fluoro groups, cyano groups, etc.) are preferred because they have very high electron-accepting properties. Specific examples include α,α',α''-1,2,3-cyclopropanetriylidenates[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidenates[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], and α,α',α''-1,2,3-cyclopropanetriylidenates[2,3,4,5,6-pentafluorobenzeneacetonitrile]. In addition to the organic compounds mentioned above, other substances with acceptor properties that can be used include molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, manganese oxide, etc. Furthermore, the hole injection layer 111 can also be formed by phthalocyanine-based complex compounds such as phthalocyanine (abbreviated as H2Pc) and copper phthalocyanine (CuPc), aromatic amine compounds such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as DPAB) and N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviated as DNTPD), or polymers such as poly(3,4-ethylenedioxythiophene) / poly(styrene sulfonic acid) (PEDOT / PSS).Acceptor materials can extract electrons from adjacent hole transport layers (or hole transport materials) by applying an electric field. 【0111】 Furthermore, a composite material containing the above-mentioned acceptor substance in a hole-transporting material can also be used as the hole injection layer 111. By using a composite material containing the acceptor substance in a hole-transporting material, it is possible to select the material for forming the electrode regardless of the work function. In other words, not only materials with a large work function but also materials with a small work function can be used as the first electrode 101. 【0112】 Various organic compounds can be used as hole-transporting materials in composite materials, including aromatic amine compounds, carbazole derivatives, aromatic hydrocarbons, and polymer compounds (oligomers, dendrimers, polymers, etc.). -6 cm 2 It is preferable that the material has a hole mobility of / Vs or higher. Below, we specifically list organic compounds that can be used as hole transporting materials in composite materials. 【0113】 Aromatic amine compounds that can be used in composite materials include N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviated as DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as DPAB), N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviated as DNTPD), and 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviated as DPA3B). Specifically, carbazole derivatives include 3-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviated as PCzPCA1), 3,6-bis[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviated as PCzPCA2), and 3-[N-(1-naphthyl)-N-(9-phenylcarbazole-3-yl)amino]-9-phenylcarbazole Examples of substances that can be used include bazole (abbreviated as PCzPCN1), 4,4'-di(N-carbazolyl)biphenyl (abbreviated as CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviated as TCPB), 9-[4-(10-phenylanthracene-9-yl)phenyl]-9H-carbazole (abbreviated as CzPA), and 1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene.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 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 compound may have a vinyl skeleton. Examples of aromatic hydrocarbons having a vinyl group include 4,4'-bis(2,2-diphenylvinyl)biphenyl (abbreviated as DPVBi) and 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviated as DPVPA). An organic compound according to one embodiment of the present invention can also be used. 【0114】 Furthermore, polymer compounds such as poly(N-vinylcarbazole) (abbreviated as PVK), poly(4-vinyltriphenylamine) (abbreviated as PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviated as PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviated as Poly-TPD) can also be used. 【0115】 The hole-transporting material used in the composite material is more preferably one of the following: a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, or an anthracene skeleton. In particular, it may be an aromatic amine having substituents including 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. Furthermore, it is preferable that these hole-transporting materials are substances having an N,N-bis(4-biphenyl)amino group, as this allows for the creation of light-emitting devices with a good lifetime. Examples of materials possessing the hole transport properties described above 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), and 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine). N-8-yl-4''-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d ]Fran-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) Name: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-Diphenyl-4''-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-Diphenyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-Diphenyl-4''-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-Diphenyl-4''-(4;2'-binaphthyl-1 -yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPB) iAβNBi), 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'-(carbazole-9-yl)biphenyl-4-yl]triphenyl Luamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazole-9-yl)phenyl]tris(1,1'-biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazole-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl] -N-[4-(1-naphthyl)phenyl]-9,9'-spirobio[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N-bis(4-biphenylyl)-9,9'-spirobio[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(1,1'-biphenyl-4-yl)-9,9'-spirobio[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-fluoren)-4-amine (abbreviation: oFBiSF), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-F 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-carbazole-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (Bazole-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirobio[9H-fluorene]-2-amine (abbreviation: PCBASF), N-(1,1'-biphenyl-4-yl)-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9H-fluorene-2-amine Examples include N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobio-9H-fluoren-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobio-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobio-9H-fluoren-2-amine, and N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobio-9H-fluoren-1-amine. 【0116】 Furthermore, it is even more preferable that the hole-transporting material used in the composite material has a relatively deep HOMO level between -5.7 eV and -5.4 eV. Having a relatively deep HOMO level in the hole-transporting material used in the composite material facilitates the injection of holes into the hole transport layer 112 and makes it easier to obtain a light-emitting device with a good lifetime. 【0117】 Furthermore, the organic compound described in Embodiment 1 is also a hole-transporting material and can be suitably used as a hole injection layer material for the composite material. By using the organic compound described in Embodiment 1, a layer with a low refractive index can be formed inside the EL layer 103, thereby improving the external quantum efficiency of the light-emitting device. 【0118】 Furthermore, by mixing alkali metal or alkaline earth metal fluoride into the above composite material (preferably with an atomic ratio of fluorine atoms of 20% or more in the layer), the refractive index of the layer can be reduced. This also makes it possible to form a layer with a low refractive index inside the EL layer 103, thereby improving the external quantum efficiency of the light-emitting device. 【0119】 By forming the hole injection layer 111, the hole injection performance is improved, making it possible to obtain a light-emitting device with a low driving voltage. Furthermore, organic compounds with acceptor properties are easy to deposit and form films with, making them easy to use materials. 【0120】 The hole transport layer 112 is formed by including a material having hole transport properties. The material having hole transport properties is 1 × 10 -6 cm 2It is preferable to have a hole mobility of / Vs or higher. The organic compound described in Embodiment 1 is a hole-transporting material and can be suitably used as a material for the hole transport layer. Therefore, it is preferable that the hole transport layer 112 contains the organic compound described in Embodiment 1, and it is more preferable that the hole transport layer 112 is composed of the organic compound described in Embodiment 1. By including the organic compound described in Embodiment 1 in the hole transport layer 112, a layer with a low refractive index can be formed inside the EL layer 103, making it possible to improve the external quantum efficiency of the light-emitting device. 【0121】 When a material other than the organic compound described in Embodiment 1 is used for the hole transport layer 112, the hole transport material may be 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as NPB), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviated as TPD), 4,4'-bis[N-(spiro-9,9'-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviated as BSPB), or 4-phenyl-4'-(9-phenylamino]biphenyl. Nylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3 -yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirobio[9H-fluoren]-2-amine (abbreviation: PCBA Compounds having an aromatic amine skeleton such as SF, compounds having a carbazole skeleton such as 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), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,Examples include compounds having a thiophene skeleton such as 8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviated as DBTFLP-III) and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as DBTFLP-IV), and compounds having a furan skeleton such as 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviated as DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviated as mmDBFFLBi-II). Among the above, compounds having an aromatic amine skeleton and compounds having a carbazole skeleton are preferred because they have good reliability, high hole transportability, and contribute to reducing the driving voltage. Furthermore, the materials listed as having hole-transporting properties used in the composite material of the hole injection layer 111 can also be suitably used as materials constituting the hole transport layer 112. 【0122】 The light-emitting layer 113 contains a light-emitting substance and a host material. The light-emitting layer 113 may also contain other materials. Furthermore, it may be a laminate of two layers with different compositions. 【0123】 The luminescent material may be a fluorescent material, a phosphorescent material, a material exhibiting thermally activated delayed fluorescence (TADF), or any other luminescent material. One aspect of the present invention can be more preferably applied when the luminescent layer 113 is a layer that exhibits fluorescent emission, particularly a layer that exhibits blue fluorescent emission. 【0124】 Examples of materials that can be used as fluorescent materials in the light-emitting layer 113 include the following. Other fluorescent materials can also be used. 【0125】 5,6-Bis[4-(10-phenyl-9-antryl)phenyl]-2,2'-bipyridine (abbreviation: PAP2BPy), 5,6-Bis[4'-(10-phenyl-9-antryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2BPy), N,N'-Diphenyl-N,N'-Bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyren-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 (abbreviation: 1,6mMemFLPAPrn), N,N'-bis[4-(9H-carbazole-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazole-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-( 10-phenyl-9-anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazole-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-carbazole-3-amine (abbreviation: 2PCAPPA), 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: 2DPAB) PhA), 9,10-bis(1,1'-biphenyl-2-yl)-N-[4-(9H-carbazole-9-yl)phenyl]-N-phenylanthracene-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracene-9-amine (abbreviation: DPhAPhA), coumarin 545T, N,N'-diphenylquinacridone (abbreviation: DPQd), rubren, 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]quinoridine-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]fluorantene-3,10-di Amine (abbreviation: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinoridine-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]quinoridine-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]quinoridine-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJTM), N,N'-diphenyl-N,N'-(1,6-pyrene-diyl)bis[(6-phenylbenzo[b Examples include ]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), 3,10-bis[N-(9-phenyl-9H-carbazole-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, such as pyrenediamine compounds like 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03, are preferred because they have high hole-trapping properties and excellent luminescence efficiency and reliability. 【0126】 When a phosphorescent material is used as the light-emitting material in the light-emitting layer 113, the following are some examples of materials that can be used. 【0127】 Organometallic iridium complexes having a 4H-triazole skeleton, such as Tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: [Ir(mpptz-dmp)3]), Tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Mptz)3]), Tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(iPrptz-3b)3]), Tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) ( Abbreviation: [Ir(Mptz1-mp)3]), organometallic iridium complexes having a 1H-triazole skeleton such as tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Prptz1-Me)3]), organometallic iridium complexes having an imidazole 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]phenantridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me)3]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ Iridium(III) tetrakis(1-pyrazolyl) borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridinate-N,C 2’ Iridium(III) picolinate (abbreviation: Firpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinate-N,C 2’ Iridium(III) picolinate (abbreviation: [Ir(CF3ppy)2(pic)]), bis[2-(4',6'-difluorophenyl)pyridinate-N,C 2’Examples include organometallic iridium complexes that use phenylpyridine derivatives having electron-withdrawing groups, such as iridium(III) acetylacetonate (abbreviated as FIracac), as ligands. These compounds exhibit blue phosphorescence and have emission peaks between 440 nm and 520 nm. 【0128】 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- Organometallic iridium complexes having a pyrimidine skeleton, such as (2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(mpmppm)2(acac)]), (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2(acac)]), organometallic iridium complexes having a pyrazine skeleton, such as (acetylacetonato)bis(3,5-dimethyl-2-phenylpyradinato)iridium(III) (abbreviation: [Ir(mppr-Me)2(acac)]), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyradinato)iridium(III) (abbreviation: [Ir(mppr-iPr)2(acac)]), and tris(2-phenylpyrimidinato-N,C 2’ Iridium(III) (abbreviation: [Ir(ppy)3]), bis(2-phenylpyridinate-N,C) 2’Iridium(III) acetylacetonate (abbreviation: [Ir(ppy)2(acac)]), bis(benzo[h]quinolinate)iridium(III) acetylacetonate (abbreviation: [Ir(bzq)2(acac)]), tris(benzo[h]quinolinate)iridium(III) (abbreviation: [Ir(bzq)3]), tris(2-phenylquinolinate-N,C) 2’ Iridium(III) (abbreviation: [Ir(pq)3]), bis(2-phenylquinolinato-N,C) 2’ Examples include organometallic iridium complexes with a pyridine skeleton, such as iridium(III) acetylacetonate (abbreviated as [Ir(pq)2(acac)]), and rare earth metal complexes, such as tris(acetylacetonate)(monophenanthroline)terbium(III) (abbreviated as [Tb(acac)3(Phen)]). These compounds mainly exhibit green phosphorescence and have an emission peak between 500 nm and 600 nm. Organometallic iridium complexes with a pyrimidine skeleton are particularly preferred due to their outstanding reliability and luminescence efficiency. 【0129】 Furthermore, organometallic iridium complexes having a pyrimidine skeleton, such as (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)]), and bis[4,6-di(naphthalene-1-yl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(d1npm)2(dpm)]), Organometallic iridium complexes with a pyrazine 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)]), and (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq)2(acac)]), and tris(1-phenylisoquinolinato-N,C) 2’ Iridium(III) (abbreviation: [Ir(piq)3]), bis(1-phenylisoquinolinato-N,C) 2’ Examples include organometallic iridium complexes with a pyridine skeleton, such as iridium(III) acetylacetonate (abbreviated as [Ir(piq)2(acac)]), platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (abbreviated as PtOEP), and rare earth metal complexes such as tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviated as [Eu(DBM)3(Phen)]) and tris[1-(2-tenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviated as [Eu(TTA)3(Phen)]). These compounds exhibit red phosphorescence and have emission peaks between 600 nm and 700 nm. Furthermore, organometallic iridium complexes with a pyrazine skeleton produce a red emission with good chromaticity. 【0130】 In addition to the phosphorescent compounds described above, other known phosphorescent substances may be selected and used. 【0131】 As TADF materials, fullerenes and their derivatives, acridines and their derivatives, eosin derivatives, etc., can be used. Also, metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd) can be used. Examples of metal-containing porphyrins include protoporphyrin-tin fluoride complexes (SnF2(Proto IX)), mesoporphyrin-tin fluoride complexes (SnF2(Meso IX)), hematoporphyrin-tin fluoride complexes (SnF2(Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complexes (SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complexes (SnF2(OEP)), etioporphyrin-tin fluoride complexes (SnF2(Etio I)), and octaethylporphyrin-platinum chloride complexes (PtCl2OEP), as shown in the following structural formulas. 【0132】 [ka] 【0133】 Furthermore, the following structural formulas represent 2-(biphenyl-4-yl)-4,6-bis(12-phenylindoro[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviated as PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviated as PCCzTzn), 9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviated as PCCzPTzn), and 2-[4-(10H-phenoxazine-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviated as PX). Heterocyclic compounds having one or both of a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring can also be used, such as Z-TRZ, 3-[4-(5-phenyl-5,10-dihydrophenazine-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviated as PPZ-3TPT), 3-(9,9-dimethyl-9H-acridine-10-yl)-9H-xanthene-9-one (abbreviated as ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviated as DMAC-DPS), and 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthracene]-10'-one (abbreviated as ACRSA). The heterocyclic compound is preferred because it has both a π-electron-excess heteroaromatic ring and a π-electron-deficient heteroaromatic ring, resulting in high electron transport and hole transport properties. Among the skeletons having a π-electron-deficient heteroaromatic ring, the pyridine skeleton, diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), and triazine skeleton are preferred because they are stable and reliable. In particular, the benzoflopyrimidine skeleton, benzothienopyrimidine skeleton, benzoflopyrazine skeleton, and benzothienopyrazine skeleton are preferred because they have high acceptability and are reliable. Furthermore, among the skeletons having a π-electron-excess heteroaromatic ring, the acridine skeleton, phenoxazine skeleton, phenothiazine skeleton, furan skeleton, thiophene skeleton, and pyrrole skeleton are preferred because they are stable and reliable, and therefore it is preferable to have at least one of these skeletons.Furthermore, a dibenzofuran skeleton is preferred as the furan skeleton, and a dibenzothiophene skeleton is preferred as the thiophene skeleton. In addition, as the pyrrole skeleton, indole skeleton, carbazole skeleton, indrocarbazole skeleton, bicarbazole skeleton, and 3-(9-phenyl-9H-carbazole-3-yl)-9H-carbazole skeleton are particularly preferred. Substances in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded are particularly preferred because both the electron-donating and electron-accepting properties of the π-electron-rich heteroaromatic ring are strengthened, and the energy difference between the S1 and T1 levels is reduced, thus efficiently obtaining thermally activated delayed fluorescence. In addition, an aromatic ring to which an electron-withdrawing group such as a cyano group is bonded may be used instead of the π-electron-deficient heteroaromatic ring. Furthermore, aromatic amine skeletons, phenazine skeletons, etc., can be used as the π-electron-rich skeleton. Furthermore, as π-electron-deficient skeletons, xanthene skeletons, thioxanthene dioxide skeletons, oxadiazole skeletons, triazole skeletons, imidazole skeletons, anthraquinone skeletons, boron-containing skeletons such as phenylborane and volanthrene, aromatic rings having a nitrile group or a cyano group such as benzonitrile or cyanobenzene, heteroaromatic rings, carbonyl skeletons such as benzophenone, phosphine oxide skeletons, sulfone skeletons, etc., can be used. In this way, π-electron-deficient skeletons and π-electron-excess skeletons can be used instead of at least one of π-electron-deficient heteroaromatic rings and π-electron-excess heteroaromatic rings. 【0134】 [ka] 【0135】 TADF materials are materials that have a small difference between the S1 and T1 energy levels and possess the ability to convert energy from triplet excitation energy to singlet excitation energy through reverse intersystem crossing. Therefore, triplet excitation energy can be upconverted to singlet excitation energy with only a small amount of thermal energy (reverse intersystem crossing), and singlet excited states can be efficiently generated. Furthermore, triplet excitation energy can be converted into luminescence. 【0136】 Furthermore, an excited complex (also called an exciplex) that forms an excited state with two types of substances has an extremely small difference between the S1 and T1 levels and functions as a TADF material that can convert triplet excitation energy into singlet excitation energy. 【0137】 Furthermore, the phosphorescence spectrum observed at low temperatures (e.g., 77K to 10K) can be used as an indicator of the T1 level. For TADF materials, when a tangent is drawn at the short-wavelength tail of the fluorescence spectrum and the energy at the wavelength of the extrapolation is taken as the S1 level, and when a tangent is drawn at the short-wavelength tail of the phosphorescence spectrum and the energy at the wavelength of the extrapolation is taken as the T1 level, it is preferable that the difference between S1 and T1 is 0.3 eV or less, and more preferably 0.2 eV or less. 【0138】 Furthermore, when using TADF material as a light-emitting material, it is preferable that the S1 level of the host material is higher than the S1 level of the TADF material. Also, it is preferable that the T1 level of the host material is higher than the T1 level of the TADF material. 【0139】 Various carrier transport materials can be used as the host material for the light-emitting layer, such as electron transport materials, hole transport materials, and the TADF material mentioned above. 【0140】 Preferred materials with hole transport properties include organic compounds having an amine skeleton or a π-electron-rich heteroaromatic ring skeleton. For example, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as NPB), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviated as TPD), 4,4'-bis[N-(spiro-9,9'-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviated as BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviated as BPAFLP), 4-phenyl Lu-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBANB), 4 Aromatic amine bones such as ,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), and N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirobio[9H-fluoren]-2-amine (abbreviation: PCBASF). Compounds having a carbazole skeleton, such as 1,3-bis(N-carbazolyl)benzene (abbreviated as mCP), 4,4'-di(N-carbazolyl)biphenyl (abbreviated as CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviated as CzTP), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviated as PCCP), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviated as DBT3P-II), 2,Examples include compounds having a thiophene skeleton such as 8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviated as DBTFLP-III) and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as DBTFLP-IV), and compounds having a furan skeleton such as 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviated as DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviated as mmDBFFLBi-II). Among the above, compounds having an aromatic amine skeleton and compounds having a carbazole skeleton are preferred because they have good reliability, high hole transportability, and contribute to reducing the driving voltage. Organic compounds described in Embodiment 1 can also be used. 【0141】 Preferred materials with electron transport properties include metal complexes such as bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviated as BeBq2), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviated as BAlq), bis(8-quinolinolato)zinc(II) (abbreviated as Znq), bis[2-(2-benzoxazollyl)phenolato]zinc(II) (abbreviated as ZnPBO), and bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviated as ZnBTZ), as well as organic compounds having a π-electron-deficient heteroaromatic ring skeleton. Examples of organic compounds having a π-electron-deficient heteroaromatic ring skeleton include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated as PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviated as TAZ), and 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated as TAZ). [Diazole-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole-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-be Heterocyclic compounds having a polyazole skeleton such as nzoimidazole (abbreviation: mDBTBIm-II), 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- Heterocyclic compounds having a diazine skeleton, such as carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), and 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), and 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'-spirobio(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: m Examples include heterocyclic compounds having a triazine skeleton, such as BnfBPTzn, 2-{3-[3-(benzo"b"naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviated as mBnfBPTzn-02), and heterocyclic compounds having a pyridine skeleton, such as 3,5-bis[3-(9H-carbazole-9-yl)phenyl]pyridine (abbreviated as 35DCzPPy) and 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviated as TmPyPB). Among the above, heterocyclic compounds having a diazine skeleton, heterocyclic compounds having a triazine skeleton, and heterocyclic compounds having a pyridine skeleton are preferred due to their good reliability. In particular, heterocyclic compounds having a diazine (pyrimidine, pyrazine, etc.) skeleton have high electron transport properties and contribute to reducing the driving voltage. 【0142】 The TADF materials listed above can be used as host materials. When a TADF material is used as a host material, the triplet excitation energy generated by the TADF material is converted into singlet excitation energy through reverse intersystem crossing, and this energy is then transferred to the light-emitting material, thereby increasing the luminescence efficiency of the light-emitting device. In this case, the TADF material functions as an energy donor, and the light-emitting material functions as an energy acceptor. 【0143】 This is particularly effective when the light-emitting material is a fluorescent material. Furthermore, in order to obtain high luminescence efficiency, it is preferable that the S1 level of the TADF material is higher than that of the fluorescent material. Also, it is preferable that the T1 level of the TADF material is higher than that of the fluorescent material. Therefore, it is preferable that the T1 level of the TADF material is higher than that of the fluorescent material. 【0144】 Furthermore, it is preferable to use a TADF material that exhibits emission that overlaps with the wavelength of the lowest-energy absorption band of the fluorescent material. This is preferable because it allows for smooth transfer of excitation energy from the TADF material to the fluorescent material, resulting in efficient emission. 【0145】 Furthermore, for singlet excitation energy to be efficiently generated from triplet excitation energy by 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 achieve this, it is preferable that the fluorescent material has protecting groups around the luminescent phosphodiocyte (the skeleton that causes luminescence). Preferred protecting groups are substituents without π bonds, and saturated hydrocarbons are preferred. Specifically, 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 preferable to have multiple protecting groups. Substituents without π bonds have poor carrier transport function, and therefore can increase the distance between the TADF material and the luminescent phosphodiocyte of the fluorescent material with little effect on carrier transport and carrier recombination. Here, the luminescent phosphodiocyte refers to the atomic group (skeleton) that causes luminescence in the fluorescent material. The luminescent phosphodiosity preferably has a skeleton containing π bonds, preferably contains an aromatic ring, and preferably has a condensed aromatic ring or a condensed heteroaromatic ring. Examples of condensed aromatic rings or condensed heteroaromatic rings include phenanthrene skeletons, stilbene skeletons, acridone skeletons, phenoxazine skeletons, and phenothiazine skeletons. Fluorescent materials having naphthalene, anthracene, fluorene, chrysene, triphenylene, tetracene, pyrene, perylene, coumarin, quinacridone, or naphthobisbenzofuran skeletons are particularly preferred due to their high fluorescence quantum yield. 【0146】 When using a fluorescent material as the light-emitting material, a material having an anthracene skeleton is preferred as the host material. Using a material having an anthracene skeleton as the host material for a fluorescent material makes it possible to realize a light-emitting layer with good luminescence efficiency and durability. Among the materials having an anthracene skeleton to be used as the host material, materials having a diphenylanthracene skeleton, and especially a 9,10-diphenylanthracene skeleton, are preferred because they are chemically stable. Furthermore, while a carbazole skeleton is preferred as the host material because it improves hole injection and transport, a benzocarbazole skeleton, in which a benzene ring is further condensed into carbazole, is even more preferred because the HOMO is about 0.1 eV shallower than carbazole, making it easier for holes to enter. In particular, a dibenzocarbazole skeleton is preferred as the HOMO is about 0.1 eV shallower than 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 that simultaneously possesses a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzocarbazole skeleton, or a dibenzocarbazole skeleton). Furthermore, from the viewpoint of hole injection and transport properties, 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 (abbreviated as PCzPA), 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPN), 9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviated as CzPA), and 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole. Examples include ruvasol (abbreviated as cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]-benzo[b]naphtho[1,2-d]furan (abbreviated as 2mBnfPPA), 9-phenyl-10-{4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4'-yl}anthracene (abbreviated as FLPPA), and 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviated as αN-βNPAnth).In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA exhibit very good characteristics and are therefore preferred choices. 【0147】 The host material may be a mixture of multiple substances, and when using a mixed host material, it is preferable to mix an electron-transporting material with a hole-transporting material. By mixing an electron-transporting material with a hole-transporting material, the transport properties of the light-emitting layer 113 can be easily adjusted, and the recombination region can also be easily controlled. The weight ratio of the hole-transporting material to the electron-transporting material should be 1:19 to 19:1. 【0148】 Furthermore, phosphorescent materials can be used as part of the above-mentioned mixed materials. When a fluorescent material is used as the light-emitting material, the phosphorescent material can be used as an energy donor to supply excitation energy to the fluorescent material. 【0149】 Furthermore, these mixed materials may form an excited complex. It is preferable to select a combination that forms an excited complex that exhibits emission overlapping with the wavelength of the lowest-energy absorption band of the luminescent material, as this facilitates smooth energy transfer and efficiently obtains light emission. This configuration is also preferable because it reduces the driving voltage. 【0150】 Furthermore, at least one of the materials forming the excitation complex may be a phosphorescent material. By doing so, the triplet excitation energy can be efficiently converted to singlet excitation energy through reverse intersystem crossing. 【0151】 For efficient excitation complex formation, it is preferable that the HOMO level of the hole-transporting material is above the HOMO level of the electron-transporting material. Furthermore, it is preferable that the LUMO level of the hole-transporting material is above the LUMO level of the electron-transporting material. The LUMO and HOMO levels of the materials can be derived from the electrochemical properties (reduction potential and oxidation potential) of the materials measured by cyclic voltammetry (CV). 【0152】 The formation of excited complexes can be confirmed, for example, by comparing the emission spectra of a hole-transporting material, an electron-transporting material, and a mixed film made by mixing these materials, and observing that the emission spectrum of the mixed film shifts to a longer wavelength than the emission spectra of each individual material (or has a new peak on the longer wavelength side). Alternatively, it can be confirmed by comparing the transient photoluminescence (PL) of a hole-transporting material, the transient PL of an electron-transporting material, and the transient PL of a mixed film made by mixing these materials, and observing differences in the transient response, such as the transient PL lifetime of the mixed film having a longer lifetime component or a larger proportion of the delayed component than the transient PL lifetime of each individual material. Furthermore, the transient PL mentioned above can be replaced with transient electroluminescence (EL). That is, the formation of excited complexes can also be confirmed by comparing the transient EL of a hole-transporting material, the transient EL of an electron-transporting material, and the transient EL of a mixed film made by mixing these materials, and observing the differences in the transient response. 【0153】 The electron transport layer 114 is a layer containing an electron-transporting material. As the electron-transporting material, any of the electron-transporting materials listed above as usable in the host material can be used. 【0154】 Furthermore, the electron transport layer preferably contains an electron-transporting material and an alkali metal or alkaline earth metal in elemental form, compound, or complex form. In addition, the electron transport layer 114 has an electron mobility of 1 × 10 at an electric field strength [V / cm] square root of 600. -7 cm2 / Vs or more 5×10 -5 cm 2 It is preferable that the value is less than or equal to / Vs. By reducing the electron transport properties in the electron transport layer 114, the amount of electrons injected into the light-emitting layer can be controlled, and it is possible to prevent the light-emitting layer from becoming electron-excessive. This configuration is particularly preferable because it results in a good lifetime when the hole injection layer is formed as a composite material and the HOMO level of the material having hole transport properties in the composite material is a relatively deep HOMO level between -5.7eV and -5.4eV. In this case, it is preferable that the HOMO level of the material having electron transport properties is -6.0eV or higher. Furthermore, it is preferable that the material having electron transport properties is an organic compound having an anthracene skeleton, and more preferably an organic compound containing both an anthracene skeleton and a heterocyclic skeleton. The heterocyclic skeleton is preferably a nitrogen-containing five-membered ring skeleton or a nitrogen-containing six-membered ring skeleton. These heterocyclic skeletons are particularly preferably nitrogen-containing five-membered ring skeletons or nitrogen-containing six-membered ring skeletons that contain two heteroatoms in the ring, such as pyrazole rings, imidazole rings, oxazole rings, thiazole rings, pyrazine rings, pyrimidine rings, and pyridazine rings. Furthermore, the alkali metal or alkaline earth metal element, compound, or complex is preferably that which contains an 8-hydroxyquinolinate structure. Specifically, examples include 8-hydroxyquinolinate-lithium (abbreviated as Liq) and 8-hydroxyquinolinate-sodium (abbreviated as Naq). In particular, complexes of monovalent metal ions, especially lithium complexes, are preferred, with Liq being more preferred. When an 8-hydroxyquinolinate structure is included, its methyl-substituted derivatives (e.g., 2-methyl-substituted derivatives or 5-methyl-substituted derivatives) can also be used. Furthermore, it is preferable that within the electron transport layer, there is a concentration difference (including cases where it is zero) of alkali metals or alkaline earth metals in elemental form, compound, or complex form along the thickness direction. 【0155】 Between the electron transport layer 114 and the second electrode 102, an electron injection layer 115 may be provided, containing an alkali metal or alkaline earth metal or a compound thereof, such as lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), or 8-hydroxyquinolinatolithium (abbreviated as Liq). The electron injection layer 115 may be a layer made of an electron-transporting material containing an alkali metal or alkaline earth metal or a compound thereof, or an electride may be used. Examples of electrides include a substance obtained by adding electrons to a mixed oxide of calcium and aluminum at a high concentration. 【0156】 Furthermore, as the electron injection layer 115, it is also possible to use a layer containing an electron-transporting substance (preferably an organic compound having a bipyridine skeleton) with an alkali metal or alkaline earth metal fluoride at a concentration above that which results in a microcrystalline state (50 wt% or more). Since this layer has a low refractive index, it is possible to provide a light-emitting device with better external quantum efficiency. 【0157】 Alternatively, a charge generation layer 116 may be provided instead of the electron injection layer 115 (Figure 3(B)). The charge generation layer 116 is a layer that can inject holes into the layer in contact with the cathode side and electrons into the layer in contact with the anode side by applying a potential. The charge generation layer 116 includes at least a P-type layer 117. The P-type layer 117 is preferably formed using a composite material listed above as a material that can constitute the hole injection layer 111. The P-type layer 117 may also be formed by laminating a film containing the acceptor material and a film containing the hole transport material as materials that constitute the composite material. By applying a potential to the P-type layer 117, electrons are injected into the electron transport layer 114 and holes are injected into the second electrode 102, which is the cathode, and the light-emitting device operates. Furthermore, since the organic compound in one embodiment of the present invention is an organic compound with a low refractive index, by using it in the P-type layer 117, a light-emitting device with good external quantum efficiency can be obtained. 【0158】 Furthermore, it is preferable that the charge generation layer 116 includes, in addition to the P-type layer 117, one or both of the electron relay layer 118 and the electron injection buffer layer 119. 【0159】 The electron relay layer 118 contains at least an electron-transporting material and has the function of preventing interaction between the electron injection buffer layer 119 and the P-type layer 117, thereby smoothly transferring electrons. The LUMO level of the electron-transporting material contained in the electron relay layer 118 is preferably between the LUMO level of the acceptor material in the P-type layer 117 and the LUMO level of the material contained in the layer in contact with the charge generation layer 116 in the electron transport layer 114. The specific energy level of the LUMO level of the electron-transporting material used in the electron relay layer 118 is preferably -5.0 eV or higher, more preferably -5.0 eV or higher and -3.0 eV or lower. It is preferable to use a phthalocyanine-based material or a metal complex having a metal-oxygen bond and an aromatic ligand as the electron-transporting material used in the electron relay layer 118. 【0160】 The electron injection buffer layer 119 can use materials with high electron injection potential, such as alkali metals, alkaline earth metals, rare earth metals, and compounds thereof (alkali metal compounds (including oxides such as lithium oxide, halides, and carbonates such as lithium carbonate and cesium carbonate), alkaline earth metal compounds (including oxides, halides, and carbonates), or rare earth metal compounds (including oxides, halides, and carbonates)). 【0161】 Furthermore, if the electron injection buffer layer 119 is formed by including an electron-transporting substance and a donor substance, the donor substance can include alkali metals, alkaline earth metals, rare earth metals, and compounds thereof (alkali metal compounds (including oxides such as lithium oxide, halides, and carbonates such as lithium carbonate and cesium carbonate), alkaline earth metal compounds (including oxides, halides, and carbonates), or rare earth metal compounds (including oxides, halides, and carbonates)), as well as organic compounds such as tetratianaphthalene (abbreviated as TTN), nickerosene, and decamethylnickerosene. The electron-transporting substance can be formed using the same materials as those used to constitute the electron transport layer 114 described above. 【0162】 As the material forming the second electrode 102, metals, alloys, electrically conductive compounds, and mixtures thereof with a small work function (specifically, 3.8 eV or less) can be used. Specific examples of such cathode materials include alkali metals such as lithium (Li) and cesium (Cs), elements belonging to Group 1 or 2 of the periodic table such as magnesium (Mg), calcium (Ca), and strontium (Sr), and 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 second electrode 102 and the electron transport layer, various conductive materials such as Al, Ag, ITO, silicon, or indium oxide-tin oxide containing silicon oxide can be used as the second electrode 102, regardless of the magnitude of their work functions. These conductive materials can be formed using dry methods such as vacuum deposition and sputtering, as well as inkjet and spin coating methods. Alternatively, they may be formed using wet methods such as the sol-gel method, or using a paste made of a metal material. 【0163】 Furthermore, various methods can be used to form the EL layer 103, regardless of whether they are dry or wet methods. For example, vacuum deposition, gravure printing, offset printing, screen printing, inkjet printing, or spin coating may be used. 【0164】 Furthermore, each electrode or layer described above may be formed using different film deposition methods. 【0165】 The configuration of the layer provided between the first electrode 101 and the second electrode 102 is not limited to those described above. However, a configuration is preferred in which a light-emitting region is provided at a location away from the first electrode 101 and the second electrode 102 where holes and electrons recombine, in order to suppress quenching that occurs when the light-emitting region is in close proximity to the electrode or the metal used in the carrier injection layer. 【0166】 Furthermore, the hole transport layer and electron transport layer in contact with the light-emitting layer 113, and especially the carrier transport layer near the recombination region in the light-emitting layer 113, are preferably composed of a material whose band gap is larger than that 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. 【0167】 Next, an embodiment of a light-emitting device (also called a stacked element or tandem element) with a configuration in which multiple light-emitting units are stacked will be described with reference to Figure 3(C). This light-emitting device has multiple light-emitting units between the anode and the cathode. Each light-emitting unit has a configuration almost identical to the EL layer 103 shown in Figure 3(A). In other words, the light-emitting device shown in Figure 3(C) is a light-emitting device with multiple light-emitting units, while the light-emitting device shown in Figure 3(A) or Figure 3(B) is a light-emitting device with one light-emitting unit. 【0168】 In Figure 3(C), a first light-emitting unit 511 and a second light-emitting unit 512 are stacked between the anode 501 and the cathode 502, and a charge generation layer 513 is provided between the first light-emitting unit 511 and the second light-emitting unit 512. The anode 501 and the cathode 502 correspond to the first electrode 101 and the second electrode 102 in Figure 3(A), respectively, and the same components as described in the explanation of Figure 3(A) can be applied. Furthermore, the first light-emitting unit 511 and the second light-emitting unit 512 may have the same configuration or different configurations. 【0169】 The charge generation layer 513 has the function of injecting electrons into one light-emitting unit and holes into the other light-emitting unit when a voltage is applied to the anode 501 and cathode 502. That is, in Figure 3(C), when a voltage is applied such that the potential of the anode is higher than the potential of the cathode, the charge generation layer 513 only needs to inject electrons into the first light-emitting unit 511 and holes into the second light-emitting unit 512. 【0170】 The charge generation layer 513 is preferably formed with the same configuration as the charge generation layer 116 described in Figure 3(B). The composite material of organic compound and metal oxide has excellent carrier implantation and carrier transport properties, enabling low-voltage and low-current operation. If the anode side of the light-emitting unit is in contact with the charge generation layer 513, the charge generation layer 513 can also act as a hole injection layer for the light-emitting unit, so the light-emitting unit does not need to have a hole injection layer. 【0171】 Furthermore, when an electron injection buffer layer 119 is provided in the charge generation layer 513, the electron injection buffer layer 119 plays the role of an electron injection layer in the anode-side light-emitting unit, so it is not necessarily required to form an electron injection layer in the anode-side light-emitting unit. 【0172】 Figure 3(C) illustrates a light-emitting device having two light-emitting units, but the same principles can be applied to light-emitting devices with three or more stacked light-emitting units. As in the light-emitting device according to this embodiment, by arranging multiple light-emitting units separated between a pair of electrodes by a charge generation layer 513, high-brightness light emission can be achieved while maintaining a low current density, and a long-life element can be realized. Furthermore, a light-emitting device that can be driven at a low voltage and consumes little power can be realized. 【0173】 Furthermore, by making the light-emitting colors of each light-emitting unit different, it is possible to obtain a desired color of light emission from the entire light-emitting device. For example, in a light-emitting device having two light-emitting units, it is possible to obtain a light-emitting device that emits white light as a whole by obtaining red and green light-emitting colors from the first light-emitting unit and blue light-emitting color from the second light-emitting unit. 【0174】 Furthermore, each layer, such as the EL layer 103, the first light-emitting unit 511, the second light-emitting unit 512, and the charge generation layer, as well as the electrodes, can be formed using methods such as vapor deposition (including vacuum deposition), droplet ejection (also known as inkjet printing), coating, and gravure printing. They may also contain low-molecular-weight materials, medium-molecular-weight materials (including oligomers and dendrimers), or polymer materials. 【0175】 (Embodiment 3) This embodiment describes a light-emitting device using the light-emitting device described in Embodiment 2. 【0176】 In this embodiment, a light-emitting device fabricated using the light-emitting device described in Embodiment 2 will be explained with reference to Figure 4. Figure 4(A) is a top view showing the light-emitting device, and Figure 4(B) is a cross-sectional view obtained by cutting Figure 4(A) along A and C. This light-emitting device includes a drive circuit section (source line drive circuit) 601, a pixel section 602, and a drive circuit section (gate line drive circuit) 603, all indicated by dotted lines, to control the light emission of the light-emitting device. Furthermore, 604 is a sealing substrate, and 605 is a sealing material, with the area enclosed by the sealing material 605 being a space 607. 【0177】 The routing wiring 608 is for transmitting signals input to the source line drive circuit 601 and the gate line drive circuit 603, and receives video signals, clock signals, start signals, reset signals, etc. from the FPC (flexible printed circuit) 609, which serves as an external input terminal. Although only the FPC is shown in this illustration, a printed circuit 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 the state in which the FPC or PWB is attached to it. 【0178】 Next, the cross-sectional structure will be explained using Figure 4(B). A drive circuit section and a pixel section are formed on the element substrate 610, and here, the source line drive circuit 601, which is the drive circuit section, and one pixel in the pixel section 602 are shown. 【0179】 The element substrate 610 may be manufactured using a substrate made of glass, quartz, organic resin, metal, alloy, semiconductor, or other materials, as well as a plastic substrate made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fluoride), polyester, or acrylic resin. 【0180】 The structure of the transistors used in the pixels and driving circuits is not particularly limited. For example, they may be inverse staggered transistors or staggered transistors. They may also be top-gate or bottom-gate transistors. The semiconductor material used for the transistors is not particularly limited; for example, silicon, germanium, silicon carbide, gallium nitride, etc., can be used. Alternatively, an oxide semiconductor containing at least one of indium, gallium, and zinc, such as an In-Ga-Zn metal oxide, may be used. 【0181】 The crystallinity of the semiconductor material used in the transistor is not particularly limited; amorphous semiconductors, crystalline semiconductors (microcrystalline semiconductors, polycrystalline semiconductors, single-crystal semiconductors, or semiconductors having a crystalline region in part) may be used. Using a crystalline semiconductor is preferable because it can suppress the degradation of transistor characteristics. 【0182】 Here, it is preferable to use oxide semiconductors for semiconductor devices such as transistors used in the pixels and driving circuits described above, as well as transistors used in touch sensors and the like, which will be described later. In particular, it is preferable to use oxide semiconductors with a wider bandgap than silicon. By using oxide semiconductors with a wider bandgap than silicon, the current in the off state of the transistor can be reduced. 【0183】 The above oxide semiconductor preferably contains at least indium (In) or zinc (Zn). More preferably, it is an oxide semiconductor containing an oxide represented as an In-M-Zn oxide (where M is a metal such as Al, Ti, Ga, Ge, Y, Zr, Sn, La, Ce, or Hf). 【0184】 In particular, it is preferable to use an oxide semiconductor film as the semiconductor layer, which has multiple crystalline portions, the c-axis of which is oriented perpendicular to the surface on which the semiconductor layer is formed or to the upper surface of the semiconductor layer, and which does not have grain boundaries between adjacent crystalline portions. 【0185】 By using such materials as semiconductor layers, fluctuations in electrical properties can be suppressed, enabling the realization of highly reliable transistors. 【0186】 Furthermore, due to its low off-current, the transistor having the aforementioned semiconductor layer can retain the charge stored in the capacitor via the transistor for a long period of time. By applying such transistors to pixels, it becomes possible to maintain the gradation of the image displayed in each display area while simultaneously stopping the drive circuit. As a result, electronic devices with extremely reduced power consumption can be realized. 【0187】 It is preferable to provide an undercoat to stabilize the characteristics of the transistor. As the undercoat, an inorganic insulating film such as a silicon oxide film, silicon nitride film, silicon oxynitride film, or silicon nitride film can be used and fabricated as a single layer or in layers. The undercoat can be formed using sputtering, CVD (Chemical Vapor Deposition) (plasma CVD, thermal CVD, MOCVD (Metal Organic CVD), etc.), ALD (Atomic Layer Deposition), coating, printing, etc. Note that the undercoat may be omitted if not necessary. 【0188】 Note that FET623 is one of the transistors formed in the drive circuit section 601. The drive circuit can be formed using various CMOS, PMOS, or NMOS circuits. In this embodiment, a driver-integrated type with the drive circuit formed on the substrate is shown, but this is not necessarily required, and the drive circuit can be formed externally instead of on the substrate. 【0189】 Furthermore, although the pixel section 602 is formed by a plurality of pixels including a switching FET 611 and a current control FET 612 and a first electrode 613 electrically connected to its drain, it is not limited to this, and the pixel section may be a combination of three or more FETs and a capacitive element. 【0190】 An insulator 614 is formed to cover the end portion of the first electrode 613. Here, it can be formed by using a positive photosensitive acrylic resin film. 【0191】 Also, in order to make the coating property of the EL layer and the like to be formed later good, a curved surface having a curvature is formed at the upper end portion or the lower end portion 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 radius of curvature (0.2 μm to 3 μm) only at the upper end portion of the insulator 614. Also, as the insulator 614, either a negative photosensitive resin or a positive photosensitive resin can be used. 【0192】 An EL layer 616 and a second electrode 617 are respectively formed on the first electrode 613. Here, as the material used for the first electrode 613 that functions as an anode, it is desirable to use a material having a large work function. For example, in addition to single-layer films such as ITO films, indium tin oxide films containing silicon, indium oxide films containing 2 to 20 wt% of zinc oxide, titanium nitride films, chromium films, tungsten films, Zn films, Pt films, etc., a laminate of a titanium nitride film and a film mainly composed of aluminum, a three-layer structure of a titanium nitride film, a film mainly composed of aluminum, and a titanium nitride film can be used. Note that when a laminated structure is used, the resistance as a wiring is low, good ohmic contact can be achieved, and it can further function as an anode. 【0193】 Also, the EL layer 616 is formed by various methods such as a vapor deposition method using a vapor deposition mask, an inkjet method, and a spin coating method. The EL layer 616 includes the configuration as described in Embodiment 2. Also, as other materials constituting the EL layer 616, a low molecular compound or a high molecular compound (including oligomers and dendrimers) may be used. 【0194】 Furthermore, as the material used for the second electrode 617 formed on the EL layer 616 and functioning as a cathode, it is preferable to use a material with a small work function (Al, Mg, Li, Ca, or their alloys and compounds (MgAg, MgIn, AlLi, etc.)). When the light generated in the EL layer 616 passes through the second electrode 617, as the second electrode 617, it is good to use a laminate of a thin metal film with a reduced film thickness and a transparent conductive film (ITO, indium oxide containing 2 - 20 wt% zinc oxide, indium tin oxide containing silicon, zinc oxide (ZnO), etc.). 【0195】 Note that a light-emitting device is formed by 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 2. Although the pixel portion is formed of a plurality of light-emitting devices, in the light-emitting device of the present embodiment, both the light-emitting device described in Embodiment 2 and the light-emitting device having other configurations may be mixed. 【0196】 Furthermore, by bonding the sealing substrate 604 to the element substrate 610 with the sealing material 605, a structure is formed in which the light-emitting device 618 is provided in the space 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealing material 605. The space 607 is filled with a filling material, and in addition to the case where an inert gas (nitrogen, argon, etc.) is filled, it may also be filled with a sealing material. Forming a recess in the sealing substrate and providing a drying material therein can suppress deterioration due to the influence of moisture, which is a preferable configuration. 【0197】 Note that it is preferable to use an epoxy resin and glass frit for the sealing material 605. Also, these materials are desirably materials that do not permeate moisture and oxygen as much as possible. In addition to a glass substrate and a quartz substrate, a plastic substrate made of FRP (Fiber Reinforced Plastics), PVF (polyvinyl fluoride), polyester, acrylic resin, etc. can be used as the material for the sealing substrate 604. 【0198】 Although not shown in Figure 4, a protective film may be provided on the second electrode. The protective film may be made of an organic resin film or an inorganic insulating film. Alternatively, the protective film may be formed to cover the exposed portion of the sealing material 605. Furthermore, the protective film can be provided to cover the surface and sides of the pair of substrates, the sealing layer, the insulating layer, and other exposed sides. 【0199】 The protective film can be made of a material that is impermeable to impurities such as water. Therefore, it is possible to effectively suppress the diffusion of impurities such as water from the outside to the inside. 【0200】 Materials that constitute the protective film can include oxides, nitrides, fluorides, sulfides, ternary compounds, metals, or polymers. For example, materials 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, or indium oxide can be used. Materials containing aluminum nitride, hafnium nitride, silicon nitride, tantalum nitride, titanium nitride, niobium nitride, molybdenum nitride, zirconium nitride, or gallium nitride can be used. Nitrides containing titanium and aluminum, oxides containing titanium and aluminum, oxides containing aluminum and zinc, sulfides containing manganese and zinc, sulfides containing cerium and strontium, oxides containing erbium and aluminum, oxides containing yttrium and zirconium can be used. 【0201】 It is preferable to form the protective film using a film deposition 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 and pinholes, or a protective film with a uniform thickness. Furthermore, it is possible to reduce the damage inflicted on the processed workpiece when forming the protective film. 【0202】 For example, by using the ALD method, a uniform and defect-free protective film can be formed on surfaces with complex uneven shapes, including the top, sides, and back surfaces of touch panels. 【0203】 As described above, a light-emitting device can be obtained using the light-emitting device described in Embodiment 2. 【0204】 Since the light-emitting device in this embodiment uses the light-emitting device described in Embodiment 2, a light-emitting device with good characteristics can be obtained. Specifically, because the light-emitting device described in Embodiment 2 has good luminous efficiency, it is possible to make a light-emitting device with low power consumption. 【0205】 Figure 5 shows an example of a light-emitting device that is made full-color by forming a light-emitting device that emits white light and providing a colored layer (color filter), etc. Figure 5(A) shows a substrate 1001, a base insulating film 1002, a gate insulating film 1003, gate electrodes 1006, 1007, 1008, a first interlayer insulating film 1020, a second interlayer insulating film 1021, a peripheral portion 1042, a pixel portion 1040, a drive circuit portion 1041, first electrodes 1024W, 1024R, 1024G, 1024B of the light-emitting device, a partition wall 1025, an EL layer 1028, a second electrode 1029 of the light-emitting device, a sealing substrate 1031, a sealing material 1032, etc. 【0206】 In Figure 5(A), the colored layers (red colored layer 1034R, green colored layer 1034G, and blue colored layer 1034B) are provided on a transparent substrate 1033. A black matrix 1035 may also be provided. The transparent substrate 1033 on which the colored layers and black matrix are provided is aligned and fixed to the substrate 1001. The colored layers and black matrix 1035 are covered with an overcoat layer 1036. In Figure 5(A), there is an emissive layer that emits light to the outside without transmitting through the colored layers, and an emissive layer that emits light to the outside by transmitting through each colored layer. Light that does not transmit through the colored layers is white, and light that transmits through the colored layers is red, green, and blue, so an image can be represented with four colored pixels. 【0207】 Figure 5(B) shows an example in which colored layers (red colored layer 1034R, green colored layer 1034G, and blue colored layer 1034B) are formed between the gate insulating film 1003 and the first interlayer insulating film 1020. Thus, the colored layers may also be provided between the substrate 1001 and the encapsulating substrate 1031. 【0208】 Furthermore, although the light-emitting device described above is a bottom-emission type device that extracts light from the substrate 1001 on which the FET is formed, it may also be a top-emission type device that extracts light from the sealing substrate 1031 on which the light-emitting device is formed. A cross-sectional view of the top-emission type light-emitting device is shown in Figure 6. In this case, the substrate 1001 can be a substrate that does not transmit light. The process is the same as for the bottom-emission type light-emitting device until the connecting electrode that connects the FET and the anode of the light-emitting device is fabricated. After that, a third interlayer insulating film 1037 is formed covering the electrode 1022. This insulating film may also play a role in planarization. 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. 【0209】 The first electrodes 1024W, 1024R, 1024G, and 1024B of the light-emitting device are designated as anodes here, but they may also be cathodes. Furthermore, in the case of a top-emission type light-emitting device as shown in Figure 6, it is preferable that the first electrodes be reflective electrodes. The configuration of the EL layer 1028 is the same as that described as the EL layer 103 in Embodiment 2, and the element structure is such that white light emission can be obtained. 【0210】 In the top emission structure shown in Figure 6, sealing can be performed with a sealing substrate 1031 having colored layers (red colored layer 1034R, green colored layer 1034G, blue colored layer 1034B). A black matrix 1035 may be provided on the sealing substrate 1031 so as to be located between pixels. The colored layers (red colored layer 1034R, green colored layer 1034G, blue colored layer 1034B) and the black matrix may be covered with an overcoat layer 1036. The sealing substrate 1031 should be a translucent substrate. In addition, although an example of full-color display using four colors, red, green, blue, and white, is shown here, it is not particularly limited, and full-color display may be performed using four colors, red, yellow, green, and blue, or three colors, red, green, and blue. 【0211】 In top-emission type light-emitting devices, a microcavity structure can be suitably applied. A light-emitting device having a microcavity structure is obtained by using a reflective electrode as the first electrode and a semi-transparent / semi-reflective electrode as the second electrode. There is at least an EL layer between the reflective electrode and the semi-transparent / semi-reflective electrode, and there is at least a light-emitting layer that forms a light-emitting region. 【0212】 The reflective electrode has a visible light reflectance of 40% to 100%, preferably 70% to 100%, and its resistivity is 1 × 10⁻⁶. -2 The film thickness is assumed to be Ωcm or less. Furthermore, the semi-transparent / semi-reflective electrode has a visible light reflectance of 20% to 80%, preferably 40% to 70%, and its resistivity is 1 × 10⁻⁶. -2 Assume the membrane is less than Ωcm in diameter. 【0213】 The light emitted from the light-emitting layer contained in the EL layer is reflected and resonated by the reflective electrode and the semi-transmissive / semi-reflective electrode. 【0214】 By changing the thicknesses of the transparent conductive film, the above-mentioned composite material, the carrier transport material, etc., the optical distance between the reflective electrode and the semi-transmissive / semi-reflective electrode can be changed. Thereby, between the reflective electrode and the semi-transmissive / semi-reflective electrode, the light of the resonant wavelength can be enhanced and the light of the non-resonant wavelength can be attenuated. 【0215】 In addition, since the light (the first reflected light) reflected back by the reflective electrode causes significant interference with the light (the first incident light) directly incident from the light-emitting layer to the semi-transmissive / semi-reflective electrode, 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 to be amplified). By adjusting the optical distance, the phases of the first reflected light and the first incident light can be matched, and the light emitted from the light-emitting layer can be further amplified. 【0216】 In the above configuration, the EL layer may have a structure having a plurality of light-emitting layers or a structure having a single light-emitting layer. For example, in combination with the configuration of the above-mentioned tandem-type light-emitting device, a plurality of EL layers are provided with a charge generation layer sandwiched between them in one light-emitting device, and the configuration of forming a single or a plurality of light-emitting layers in each EL layer may be applied. 【0217】 By having a microcavity structure, it becomes possible to enhance the light-emitting intensity in the front direction of a specific wavelength, so that power consumption can be reduced. In the case of a light-emitting device that displays an image with four sub-pixels of red, yellow, green, and blue, in addition to the luminance improvement effect by yellow light emission, a microcavity structure can be applied according to the wavelength of each color in all sub-pixels, so that a light-emitting device with good characteristics can be obtained. 【0218】 Since the light-emitting device in this embodiment uses the light-emitting device described in Embodiment 2, a light-emitting device with good characteristics can be obtained. Specifically, because the light-emitting device described in Embodiment 2 has good luminous efficiency, it is possible to make a light-emitting device with low power consumption. 【0219】 Up to this point, we have described an active matrix type light-emitting device, but from here on we will describe a passive matrix type light-emitting device. Figure 7 shows a passive matrix type light-emitting device manufactured by applying the present invention. Figure 7(A) is a perspective view showing the light-emitting device, and Figure 7(B) is a cross-sectional view obtained by cutting Figure 7(A) along the X and Y lines. In Figure 7, an EL layer 955 is provided on the substrate 951 between electrodes 952 and 956. The ends of electrodes 952 are covered with an insulating layer 953. A partition layer 954 is provided on the insulating layer 953. The side walls of the partition layer 954 have a slope such that the distance between one side wall and the other side wall narrows as it approaches the substrate surface. In other words, the cross-section of the partition layer 954 in the short-side direction is trapezoidal, with the bottom side (facing the same direction as the surface direction of the insulating layer 953 and in contact with the insulating layer 953) being shorter than the top side (facing the same direction as the surface direction of the insulating layer 953 and not in contact with the insulating layer 953). By providing the partition layer 954 in this way, it is possible to prevent malfunctions of the light-emitting device caused by static electricity, etc. Furthermore, even in a passive matrix type light-emitting device, the light-emitting device described in Embodiment 2 is used, resulting in a light-emitting device with good reliability or low power consumption. 【0220】 As described above, the light-emitting device is suitable for use as a display device for representing images because it is possible to control each of the numerous minute light-emitting devices arranged in a matrix. 【0221】 Furthermore, this embodiment can be freely combined with other embodiments. 【0222】 (Embodiment 4) In this embodiment, an example of using the light-emitting device described in Embodiment 2 as an illumination device will be explained with reference to Figure 8. Figure 8(B) is a top view of the illumination device, and Figure 8(A) is a cross-sectional view of ef in Figure 8(B). 【0223】 In this embodiment, the lighting device has a first electrode 401 formed on a translucent substrate 400 which serves as a support. The first electrode 401 corresponds to the first electrode 101 in Embodiment 1. When light is extracted from the first electrode 401 side, the first electrode 401 is formed from a translucent material. 【0224】 A pad 412 for supplying voltage to the second electrode 404 is formed on the substrate 400. 【0225】 An EL layer 403 is formed on the first electrode 401. The EL layer 403 corresponds to the configuration of the EL layer 103 in Embodiment 1, or a configuration combining the light-emitting units 511, 512 and the charge-generating layer 513. Please refer to the relevant description for details on these configurations. 【0226】 A second electrode 404 is formed by covering the EL layer 403. The second electrode 404 corresponds to the second electrode 102 in Embodiment 1. When light emission is extracted from the first electrode 401 side, the second electrode 404 is formed of a material with high reflectivity. Voltage is supplied to the second electrode 404 by connecting it to the pad 412. 【0227】 As described above, the lighting device shown in this embodiment has a light-emitting device having a first electrode 401, an EL layer 403, and a second electrode 404. Since this light-emitting device is a light-emitting device with high luminous efficiency, the lighting device in this embodiment can be a lighting device with low power consumption. 【0228】 The lighting device is completed by fixing and sealing the substrate 400, on which the light-emitting device having the above configuration is formed, and the sealing substrate 407 using sealing materials 405 and 406. Either sealing material 405 or 406 may be used. In addition, a desiccant can be mixed into the inner sealing material 406 (not shown in Figure 8(B)), which allows for the adsorption of moisture and leads to improved reliability. 【0229】 Furthermore, by extending the pad 412 and a portion of the first electrode 401 outside the sealing materials 405 and 406, it can be used as an external input terminal. Alternatively, an IC chip 420 with a converter or the like may be placed on top of it. 【0230】 As described above, the lighting device described in this embodiment uses the light-emitting device described in Embodiment 2 as the EL element, and can be a light-emitting device with low power consumption. 【0231】 (Embodiment 5) This embodiment describes an example of an electronic device that includes the light-emitting device described in Embodiment 2 as part of it. The light-emitting device described in Embodiment 2 has good luminous efficiency and low power consumption. As a result, the electronic device described in this embodiment can be an electronic device having a light-emitting section with low power consumption. 【0232】 Examples of electronic devices to which the above-mentioned light-emitting devices are applied include television equipment (also called televisions or television receivers), monitors for computers, digital cameras, digital video cameras, digital photo frames, mobile phones (also called mobile phones or mobile phone devices), portable game consoles, personal digital assistants, sound playback devices, and large game machines such as pachinko machines. Specific examples of these electronic devices are shown below. 【0233】 Figure 9(A) shows an example of a television system. The television system has a display unit 7103 incorporated into a housing 7101. This figure also shows a configuration in which the housing 7101 is supported by a stand 7105. The display unit 7103 is capable of displaying images, and the display unit 7103 is constructed by arranging the light-emitting devices described in Embodiment 2 in a matrix. 【0234】 The television system can be operated using the operation switches on the housing 7101 and a separate remote control unit 7110. The operation keys 7109 on the remote control unit 7110 allow for channel and volume control, and the image displayed on the display unit 7103 can be controlled. Alternatively, the remote control unit 7110 may be configured to include a display unit 7107 that displays information output from the remote control unit 7110. 【0235】 The television system will consist of a receiver, modem, and other components. The receiver will be able to receive general television broadcasts, and by connecting to a wired or wireless communication network via the modem, it will also be possible to perform one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers, etc.) information communication. 【0236】 Figure 9(B1) shows a computer, which includes a main unit 7201, a housing 7202, a display unit 7203, a keyboard 7204, an external connection port 7205, a pointing device 7206, etc. This computer is manufactured by arranging the light-emitting devices described in Embodiment 2 in a matrix and using them for the display unit 7203. The computer in Figure 9(B1) may also take the form shown in Figure 9(B2). The computer in Figure 9(B2) has a second display unit 7210 instead of the keyboard 7204 and pointing device 7206. The second display unit 7210 is a touch panel, and input can be performed by operating the input display shown on the second display unit 7210 with a finger or a dedicated pen. In addition to the input display, the second display unit 7210 can also display other images. The display unit 7203 may also be a touch panel. Because the two screens are connected by a hinge, it is possible to prevent problems such as scratching or damaging the screens when storing or transporting the device. 【0237】 Figure 9(C) shows an example of a mobile terminal. The mobile phone includes a display unit 7402 built into the housing 7401, as well as operation buttons 7403, an external connection port 7404, a speaker 7405, a microphone 7406, and the like. The mobile phone has a display unit 7402 made by arranging the light-emitting devices described in Embodiment 2 in a matrix. 【0238】 The mobile terminal shown in Figure 9(C) can also be configured to allow information to be entered by touching the display unit 7402 with a finger or other object. In this case, operations such as making a phone call or composing an email can be performed by touching the display unit 7402 with a finger or other object. 【0239】 The display unit 7402 has three main modes. The first is a display mode that primarily displays images, the second is an input mode that primarily inputs information such as text, and the third is a display + input mode that combines the display mode and the input mode. 【0240】 For example, when making a phone call or composing an email, the display unit 7402 should be set to a text input mode, which primarily focuses on text input, and the user should perform the text input operation displayed on the screen. In this case, it is preferable to display a keyboard or number buttons on most of the screen of the display unit 7402. 【0241】 Furthermore, by providing a detection device with a tilt sensor such as a gyroscope or accelerometer inside the mobile terminal, the orientation of the mobile terminal (portrait or landscape) can be determined, and the screen display of the display unit 7402 can be automatically switched accordingly. 【0242】 Furthermore, the screen mode can be switched by touching the display unit 7402 or by operating the operation button 7403 on the housing 7401. It is also possible to switch modes depending on the type of image displayed on the display unit 7402. For example, if the image signal displayed on the display unit is video data, it can be switched to display mode; if it is text data, it can be switched to input mode. 【0243】 Furthermore, in input mode, the system may detect a signal detected by the optical sensor of the display unit 7402 and, if there is no input via touch operation on the display unit 7402 for a certain period of time, control may be made to switch the screen mode from input mode to display mode. 【0244】 The display unit 7402 can also function as an image sensor. For example, by touching the display unit 7402 with the palm or finger, palm prints, fingerprints, etc., can be captured to perform user authentication. Furthermore, by using a backlight that emits near-infrared light or a sensing light source that emits near-infrared light in the display unit, finger veins, palm veins, etc., can also be captured. 【0245】 Furthermore, the configuration shown in this embodiment can be used by appropriately combining the configurations shown in Embodiments 1 to 4. 【0246】 As described above, the application range of the light-emitting device equipped with the light-emitting device described in Embodiment 2 is extremely broad, and this light-emitting device can be applied to electronic devices in all fields. By using the light-emitting device described in Embodiment 2, it is possible to obtain electronic devices with low power consumption. 【0247】 Figure 10(A) is a schematic diagram showing an example of a cleaning robot. 【0248】 The cleaning robot 5100 has a display 5101 on its top surface, multiple cameras 5102 on its sides, a brush 5103, and control buttons 5104. Although not shown in the illustration, the cleaning robot 5100 also has wheels, a suction port, etc. on its underside. The cleaning robot 5100 is also equipped with various sensors, including an infrared sensor, an ultrasonic sensor, an accelerometer, a piezoelectric sensor, a light sensor, and a gyroscope. Furthermore, the cleaning robot 5100 is equipped with a means of wireless communication. 【0249】 The cleaning robot 5100 is self-propelled, can detect dirt 5120, and can suck up the dirt through a suction port located on its underside. 【0250】 Furthermore, the cleaning robot 5100 can analyze images captured by the camera 5102 to determine the presence or absence of obstacles such as walls, furniture, or steps. If the image analysis detects objects that could become entangled in the brush 5103, such as wiring, it can stop the brush 5103 from rotating. 【0251】 The display 5101 can display information such as the remaining battery level and the amount of dirt collected. The path taken by the cleaning robot 5100 may also be displayed on the display 5101. Alternatively, the display 5101 may be a touch panel, and operation buttons 5104 may be provided on the display 5101. 【0252】 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. Therefore, the owner of the cleaning robot 5100 can check the status of the room even when they are away from home. In addition, the display on the display 5101 can be checked on a portable electronic device such as a smartphone. 【0253】 A light-emitting device according to one aspect of the present invention can be used in a display 5101. 【0254】 The robot 2100 shown in Figure 10(B) includes a computing unit 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. 【0255】 The microphone 2102 has the function of detecting the user's voice and ambient sounds. The speaker 2104 has the function of emitting sound. The robot 2100 can communicate with the user using the microphone 2102 and speaker 2104. 【0256】 The display 2105 has the function of displaying various types of information. The robot 2100 can display the 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, and by installing it in a fixed position on the robot 2100, charging and data transfer can be made possible. 【0257】 The upper camera 2103 and the lower camera 2106 have the function of imaging the area around the robot 2100. In addition, the obstacle sensor 2107 can detect the presence or absence of obstacles in the direction of travel when the robot 2100 moves forward using the movement mechanism 2108. The robot 2100 can recognize its surrounding environment and move safely using the upper camera 2103, the lower camera 2106 and the obstacle sensor 2107. The light-emitting device according to one aspect of the present invention can be used in the display 2105. 【0258】 Figure 10(C) shows 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, a connection terminal 5006, a sensor 5007 (including functions for measuring force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation), a microphone 5008, a display unit 5002, a support unit 5012, an earphone 5013, etc. 【0259】 A light-emitting device according to one aspect of the present invention can be used in the display unit 5001 and the display unit 5002. 【0260】 Figure 11 shows an example of using the light-emitting device described in Embodiment 2 in a desk lamp, which is a lighting device. The desk lamp shown in Figure 11 has a housing 2001 and a light source 2002, and the lighting device described in Embodiment 3 may be used as the light source 2002. 【0261】 Figure 12 shows an example of using the light-emitting device described in Embodiment 2 as an indoor lighting device 3001. Since the light-emitting device described in Embodiment 2 is a light-emitting device with high luminous efficiency, it can be used as a lighting device with low power consumption. Furthermore, since the light-emitting device described in Embodiment 2 can be made to cover a large area, it can be used as a large-area lighting device. In addition, since the light-emitting device described in Embodiment 2 is thin, it can be used as a thin lighting device. 【0262】 The light-emitting device described in Embodiment 2 can also be mounted on the windshield, dashboard, etc., of an automobile. Figure 13 shows one embodiment in which the light-emitting device described in Embodiment 2 is used on the windshield, dashboard, etc., of an automobile. Display areas 5200 to 5203 are displays provided using the light-emitting device described in Embodiment 2. 【0263】 Display area 5200 and display area 5201 are display devices equipped with the light-emitting device described in Embodiment 2, which is installed on the windshield of an automobile. The light-emitting device described in Embodiment 2 can be made into a so-called see-through display device, where the opposite side is visible, by making the first electrode and the second electrode from translucent electrodes. If the display is in a see-through state, it can be installed on the windshield of an automobile without obstructing the view. When providing transistors for driving, it is preferable to use translucent transistors such as organic transistors made of organic semiconductor materials or transistors made of oxide semiconductors. 【0264】 The display area 5202 is a display device equipped with the light-emitting device described in Embodiment 2, which is provided on the pillar. By displaying images from an imaging means provided on the vehicle body on the display area 5202, the field of view obstructed by the pillar can be compensated for. Similarly, the display area 5203 provided on the dashboard can compensate for the field of view obstructed by the vehicle body by displaying images from an imaging means provided on the outside of the vehicle, thereby compensating for blind spots and enhancing safety. By displaying images in a way that compensates for the parts that are not visible, safety checks can be performed more naturally and without discomfort. 【0265】 Display area 5203 can also provide various other information, such as navigation information, speed, rotational speed, and air conditioning settings. The display items and layout can be changed as needed to suit the user's preferences. This information can also be provided in display areas 5200 to 5202. Furthermore, display areas 5200 to 5203 can also be used as lighting devices. 【0266】 Figures 14(A) and (B) also show a foldable portable information terminal 5150. The foldable portable information terminal 5150 has a housing 5151, a display area 5152, and a bending section 5153. Figure 14(A) shows the portable information terminal 5150 in its unfolded state. Figure 14(B) shows the portable information terminal in its folded state. Despite having a large display area 5152, the portable information terminal 5150 is compact and highly portable when folded. 【0267】 The display area 5152 can be folded in half by the bending portion 5153. The bending portion 5153 is composed of an expandable member and a plurality of support members. When folded, the expandable member extends, and the bending portion 5153 folds to have a radius of curvature of 2 mm or more, preferably 3 mm or more. 【0268】 The display area 5152 may also be a touch panel (input / output device) equipped with a touch sensor (input device). A light-emitting device according to one aspect of the present invention can be used in the display area 5152. 【0269】 Figures 15(A) to 15(C) also show the foldable portable information terminal 9310. Figure 15(A) shows the portable information terminal 9310 in its unfolded state. Figure 15(B) shows the portable information terminal 9310 in an intermediate state, either unfolded or folded. Figure 15(C) shows the portable information terminal 9310 in its folded state. The portable information terminal 9310 offers excellent portability in its folded state and excellent readability of the display due to its seamless, wide display area in its unfolded state. 【0270】 The display panel 9311 is supported by three housings 9315 connected by a hinge 9313. The display panel 9311 may also 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 hinge 9313. A light-emitting device according to one aspect of the present invention can be used in the display panel 9311. [Examples] 【0271】 This example presents the results of a detailed investigation into the driving voltage of a light-emitting device using a low refractive index organic compound and a light-emitting device using a comparative material. The structural formulas of the main organic compounds used in this example are shown below. 【0272】 [ka] 【0273】 [ka] 【0274】 (Method for fabricating light-emitting devices 1 to 7) First, a film of indium tin oxide (ITSO) containing silicon oxide was deposited on a glass substrate by sputtering to form the first electrode 101. The film thickness was 55 nm, and the electrode area was 2 mm × 2 mm. 【0275】 Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water, baked at 200°C for 1 hour, and then subjected to UV ozone treatment for 370 seconds. 【0276】 Then, 10 -4 The substrate was introduced into a vacuum deposition apparatus where the internal pressure was reduced to approximately Pa. After vacuum firing at 170°C for 30 minutes in the heating chamber of the vacuum deposition apparatus, the substrate was allowed to cool for about 30 minutes. 【0277】 Next, the substrate on which the first electrode 101 is formed is fixed to a substrate holder provided in a vacuum deposition apparatus so that the surface on which the first electrode 101 is formed faces downwards. Then, a hole injection layer 111 is formed on the first electrode 101 by co-depositing a low refractive index organic compound (low-n HTM) and an electron acceptor material (OCHD-001) at a weight ratio of 1:0.1 (=low-n HTM:OCHD-001) to a thickness of 10 nm using a deposition method with resistance heating. 【0278】 Furthermore, the low-n HTM used in the above light-emitting device 1-1 is N-3',5'-diter-butyl-1,1'-biphenyl-4-yl-N-1,1'-biphenyl-2-yl-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: mmtBuBioFBi), represented by the above structural formula (i); in light-emitting devices 2-1 to 2-3 it is N,N-bis(4-cyclohexylphenyl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: dchPAF), represented by the above structural formula (ii); and in light-emitting devices 3-1 and 3 -2 uses N-[(3',5'-ditterbutyl)-1,1'-biphenyl-4-yl]-N-(4-cyclohexylphenyl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: mmtBuBichPAF), represented by the above structural formula (iii), while light-emitting device 4 uses N-(3,5-ditterbutylphenyl)-N-(3',5',-ditterbutyl-1,1'-biphenyl-4-yl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: mmtBuBim), represented by the above structural formula (iv). In light-emitting devices 5-1 to 5-3, mtBuPAF is used, and N-(1,1'-biphenyl-2-yl)-N-(3,3'',5',5''-tetra-tert-butyl-1,1':3',1''-terphenyl-5-yl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: mmtBumTPoFBi-02), represented by the above structural formula (v), is used, and in light-emitting devices 6-1 to 6-3, N-(4-cyclohexylphenyl)-N-(3,3'',5',5''-tetra- -tert-butyl-1,1':3',1''-terphenyl-5-yl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as mmtBumTPChPAF-02) was used in light-emitting devices 7-1 to 7-4, while N-(3,3'',5,5''-tetra-t-butyl-1,1':3',1''-terphenyl-5'-yl)-N-(4-cyclohexylphenyl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as mmtBumTPchPAF), represented by the above structural formula (vii), was used in each of them. 【0279】 Note that if there are multiple light-emitting devices using the same low-n HTM, such as light-emitting device 2-1 to light-emitting device 2-3, they may be collectively referred to as light-emitting device 2. 【0280】 Next, on the hole injection layer 111, mmtBuBioFBi is injected into light-emitting device 1-1, dchPAF into light-emitting devices 2-1 to 2-3, mmtBuBichPAF into light-emitting devices 3-1 and 3-2, mmtBuBimmtBuPAF into light-emitting device 4, mmtBumTPoFBi-02 into light-emitting devices 5-1 to 5-3, and mmtBumTPChPAF-0 into light-emitting devices 6-1 to 6-3. In step 2, mmtBumTPchPAF was deposited to a thickness of 30 nm in light-emitting devices 7-1 to 7-4, and then N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviated as DBfBB1TP), represented by the above structural formula (viii), was deposited to a thickness of 15 nm in light-emitting devices 1-1 and 2-1, and to a thickness of 10 nm in the other light-emitting devices to form a hole transport layer 112. 【0281】 Next, 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviated as αN-βNPAnth), represented by the above structural formula (ix), and 3,10-bis[N-(9-phenyl-9H-carbazole-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviated as 3,10PCA2Nbf(IV)-02), represented by the above structural formula (x), were co-deposited in a weight ratio of 1:0.015 (=αN-βNPAnth:3,10PCA2Nbf(IV)-02) to form a light-emitting layer 113 with a film thickness of 25 nm. 【0282】 Subsequently, an electron transport layer 114 was formed on the light-emitting layer 113 by co-depositing 2-{4-[9,10-di(naphthalene-2-yl)-2-anthryl]phenyl}-1-phenyl-1H-benzimidazole (abbreviated as ZADN), represented by the above structural formula (xi), and 8-quinolinolato-lithium (abbreviated as Liq), represented by the above structural formula (xii), in a weight ratio of 1:1 (=ZADN:Liq) and with a film thickness of 25 nm. 【0283】 After forming the electron transport layer 114, an electron injection layer 115 was formed by depositing Liq to a thickness of 1 nm, and then a second electrode 102 was formed by depositing aluminum to a thickness of 200 nm to fabricate a light-emitting device. 【0284】 (Method for fabricating comparative light-emitting device 1) Comparative light-emitting device 1 was fabricated in the same manner as light-emitting device 1-1, except that mmtBuBioFBi in light-emitting device 1-1 was replaced with N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF), represented by the above structural formula (xiii). 【0285】 The element structures of the above-mentioned light-emitting device and comparative light-emitting device 1 are summarized in the table below. 【0286】 [Table 1] 【0287】 Of the above-mentioned light-emitting devices, light-emitting devices 1 to 3 are the light-emitting devices of the embodiment. 【0288】 Furthermore, the low-n HTM used in the hole injection layer and hole transport layer, and the ordinary refractive index n of the PCBBiF reference at a wavelength of 458 nm o The birefringence Δn and orientation order parameter S are shown in the table below. 【0289】 [Table 2] 【0290】 The above-mentioned light-emitting device and comparative light-emitting device were sealed with a glass substrate in a glove box under a nitrogen atmosphere to prevent exposure to the atmosphere (sealant was applied around the element, UV treatment was performed during sealing, and heat treatment was performed at 80°C for 1 hour). 【0291】 Figure 16 shows a graph plotting the difference in driving voltage (ΔV) between a comparative light-emitting device and each light-emitting device when driven at 1mA, with the y-axis representing the difference in driving voltage and the x-axis representing the birefringence Δn of the low-n HTM used at 458nm light. The plots indicated by crosses show the results for light-emitting devices that have a similar structure to light-emitting devices 1 to 7, but are fabricated using different low-n HTMs, although details are omitted. 【0292】 Figure 16 shows that light-emitting devices 1 and 2, which use low-n HTM with a birefringence Δn between 0 and 0.008, clearly have a smaller ΔV and operate at a lower voltage compared to other light-emitting devices. 【0293】 Similarly, Figure 17 shows a graph plotting the difference in driving voltage (ΔV) between a comparison light-emitting device and each light-emitting device when driven at 1 mA, with the y-axis representing the orientation order parameter S of the deposited low-n HTM used (the orientation order parameter for light at the wavelength corresponding to the longest wavelength absorption peak in the absorption spectrum of the low-n HTM), with the x-axis representing the orientation order parameter S. Similar to Figure 16, the plots shown as crosses represent the results for light-emitting devices that have the same structure as light-emitting devices 1 to 7 but are fabricated using different low-n HTMs. The absorption spectra of the deposited films of each low-n HTM are shown in Figure 26. 【0294】 Figure 17 shows that light-emitting devices 1 and 2, which use low-n HTM with an orientation order parameter S of the deposited film for light at the wavelength of the absorption peak located at the longest wavelength in the absorption spectrum in the range of -0.070 to 0.00, clearly have a smaller ΔV and are light-emitting devices with lower driving voltages compared to other light-emitting devices. 【0295】 Furthermore, despite having a relatively high birefringence Δn of 0.036 and a relatively low orientation order parameter S of -0.095, the light-emitting device 3 exhibits a smaller ΔV compared to other light-emitting devices using low-n HTM. The low-n HTM used in this light-emitting device, like the low-n HTM used in light-emitting device 1, has a para-biphenyl structure, particularly a 1,1'-biphenyl-4-yl group directly bonded to the nitrogen of the amine, which enables it to be driven at a low driving voltage. 【0296】 Furthermore, in order to have a low refractive index, low-n HTM has multiple alkyl groups having 3 to 8 carbon atoms and cycloalkyl groups having 6 to 12 carbon atoms. When these groups are bonded to the 1,1'-biphenyl-4-yl group, it is preferable that they be bonded to any of the 2', 3', 4', or 5' positions, particularly the 3' and 5' positions, as this does not hinder the carrier transport performance of low-n HTM and leads to a reduction in the driving voltage. 【0297】 On the other hand, even if the 1,1'-biphenyl-4-yl group is directly bonded to nitrogen, as in the low-n HTM of light-emitting device 4, if the C3 to C8 alkyl group and C6 to C12 cycloalkyl group are bonded to the meta position of the benzene ring closest to the nitrogen in other aryl groups bonded to the same nitrogen, the carrier transport performance is reduced, causing the driving voltage to increase. 【0298】 As described above, it was found that by using low-n HTMs with a certain range of birefringence Δn or orientation order parameter S, it is possible to obtain light-emitting devices with a low driving voltage. Furthermore, it was found that by using low-n HTMs with a specific structure, it is possible to obtain light-emitting devices with a low driving voltage over a wider range of birefringence Δn or orientation order parameter S than the above range. [Examples] 【0299】 This embodiment describes in detail a light-emitting device using an organic compound according to one aspect of the present invention. The structural formulas of representative organic compounds used in this embodiment are shown below. 【0300】 [ka] 【0301】 (Methods for fabricating light-emitting devices 1-2, 2-4, and 3-3) First, a film of indium tin oxide (ITSO) containing silicon oxide was deposited on a glass substrate by sputtering to form the first electrode 101. The film thickness was 55 nm, and the electrode area was 2 mm × 2 mm. 【0302】 Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water, baked at 200°C for 1 hour, and then subjected to UV ozone treatment for 370 seconds. 【0303】 Then, 10 -4 The substrate was introduced into a vacuum deposition apparatus where the internal pressure was reduced to approximately Pa. After vacuum firing at 170°C for 30 minutes in the heating chamber of the vacuum deposition apparatus, the substrate was allowed to cool for about 30 minutes. 【0304】 Next, the substrate on which the first electrode 101 is formed is fixed to a substrate holder provided in a vacuum deposition apparatus so that the surface on which the first electrode 101 is formed faces downwards. Then, a hole injection layer 111 is formed on the first electrode 101 by co-depositing a low refractive index organic compound (low-n HTM) and an electron acceptor material (OCHD-001) at a weight ratio of 1:0.1 (=low-n HTM:OCHD-001) to a thickness of 10 nm using a deposition method with resistance heating. 【0305】 For light-emitting devices 1-2, the low-n HTM used was N-3',5'-ditter-butyl-1,1'-biphenyl-4-yl-N-1,1'-biphenyl-2-yl-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as mmtBuBioFBi), represented by structural formula (i) above. For light-emitting devices 2-4, the N,N-bis(4-cyclohexylphenyl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as dchPAF), represented by structural formula (ii) above. For light-emitting devices 3-3, the N-[(3',5'-ditter-butyl)-1,1'-biphenyl-4-yl]-N-(4-cyclohexylphenyl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as mmtBuBichPAF), represented by structural formula (iii) above, was used. 【0306】 Next, mmtBuBioFBi was deposited on the hole injection layer 111 to a thickness of 30 nm for light-emitting devices 1-2, dchPAF for light-emitting devices 2-4, and mmtBuBichPAF for light-emitting devices 3-3. Then, N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviated as DBfBB1TP), represented by the above structural formula (viii), was deposited to a thickness of 15 nm to form the hole transport layer 112. 【0307】 Next, 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviated as αN-βNPAnth), represented by the above structural formula (ix), and 3,10-bis[N-(9-phenyl-9H-carbazole-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviated as 3,10PCA2Nbf(IV)-02), represented by the above structural formula (x), were co-deposited in a weight ratio of 1:0.015 (=αN-βNPAnth:3,10PCA2Nbf(IV)-02) to form a light-emitting layer 113 with a film thickness of 25 nm. 【0308】 Subsequently, an electron transport layer 114 was formed on the light-emitting layer 113 by co-depositing 2-{4-[9,10-di(naphthalene-2-yl)-2-anthryl]phenyl}-1-phenyl-1H-benzimidazole (abbreviated as ZADN), represented by the above structural formula (xi), and 8-quinolinolato-lithium (abbreviated as Liq), represented by the above structural formula (xii), in a weight ratio of 1:1 (=ZADN:Liq) and with a film thickness of 25 nm. 【0309】 After forming the electron transport layer 114, an electron injection layer 115 was formed by depositing Liq to a thickness of 1 nm, and then a second electrode 102 was formed by depositing aluminum to a thickness of 200 nm to fabricate a light-emitting device. 【0310】 (Method for fabricating the comparative light-emitting device 10) Comparative light-emitting device 10 was fabricated in the same manner as light-emitting devices 1-2, except that mmtBuBioFBi in light-emitting devices 1-2 was replaced with N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as PCBBiF), represented by the above structural formula (xiii). 【0311】 The element structures of the above-mentioned light-emitting device and the comparative light-emitting device are summarized in the table below. 【0312】 [Table 3] 【0313】 [Table 4] 【0314】 Furthermore, the ordinary refractive index n of the low-n HTM vapor-deposited film used in the hole injection layer and hole transport layer, and the comparative material PCBBiF vapor-deposited film o The birefringence Δn and orientation order parameter S are shown in the table below. 【0315】 [Table 5] 【0316】 The above-mentioned light-emitting device and comparative light-emitting device 10 were sealed with a glass substrate in a glove box under a nitrogen atmosphere to prevent exposure to the atmosphere (sealing material was applied around the element, UV treatment was performed during sealing, and heat treatment was performed at 80°C for 1 hour). After this, the initial characteristics of these light-emitting devices were measured. No special measures were taken to improve the removal efficiency of the glass substrate on which the light-emitting devices were fabricated. 【0317】 Figure 18 shows the luminance-current density characteristics, Figure 19 the luminance-voltage characteristics, Figure 20 the current efficiency-luminance characteristics, Figure 21 the current density-voltage characteristics, Figure 22 the power efficiency-luminance characteristics, Figure 23 the external quantum efficiency-luminance characteristics, and Figure 24 the emission spectra of each light-emitting device at 1000 cd / m². 2 Table 6 shows the main characteristics of the vicinity. A spectroradiometer (Topcon UR-UL1R) was used to measure luminance, CIE chromaticity, and emission spectrum at room temperature. The external quantum efficiency was calculated using the measured luminance and emission spectrum, assuming a Lambertsian light distribution pattern. 【0318】 [Table 6] 【0319】 As can be seen from Figures 18 to 24, the light-emitting device according to one embodiment of the present invention exhibits a driving voltage equivalent to that of the comparative light-emitting device 10, but by using a low refractive index organic compound in the hole injection layer and hole transport layer, it is a light-emitting device with significantly improved external quantum efficiency and good luminous efficiency. Therefore, the light-emitting device according to one embodiment of the present invention is a light-emitting device with low power consumption. 【0320】 Furthermore, the current density of the light-emitting devices 1-2, 2-4, 3-3, and comparative light-emitting device 10 is 50 mA / cm². 2 Figure 25 shows a graph representing the change in brightness with respect to operating time. As shown in Figure 25, it was also found that light-emitting devices 1-2, 2-4, and 3-3, which are light-emitting devices according to one aspect of the present invention, are light-emitting devices with a good lifespan. [Examples] 【0321】 <<Synthesis Example 1>> This synthesis example describes the synthesis method of N-(3',5'-ditterybutyl-1,1'-biphenyl-4-yl)-N-(1,1'-biphenyl-2-yl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as mmtBuBioFBi), an organic compound according to one embodiment of the present invention used in the examples. The structure of mmtBuBioFBi is shown below. 【0322】 [ka] 【0323】 2.22 g (7.4 mmol) of 4-chloro-3',5'-di-tert-butyl-1,1'-biphenyl, 2.94 g (8.1 mmol) of 2-(2-biphenylyl)amino-9,9-dimethylfluorene, 2.34 g (24.4 mmol) of sodium tert-butoxide (abbreviated as tBuONa), and 37 mL of xylene were placed in a three-necked flask. After degassing under reduced pressure, the flask was purged with nitrogen. 107.6 mg (0.31 mmol) of di-t-butyl (1-methyl-2,2-diphenylcyclopropyl)phosphine (abbreviated as cBRIDP®) and 28.1 mg (0.077 mmol) of allyl palladium chloride dimer (abbreviated as [PdCl(allyl)]2) were added to this mixture. The mixture was heated at 100°C for approximately 4 hours. Subsequently, the flask temperature was returned to approximately 70°C, and approximately 4 mL of water was added to precipitate the solid. The precipitated solid was filtered off. The filtrate was concentrated, and the resulting solution was purified by silica gel column chromatography. The obtained solution was concentrated, ethanol was added, and the concentration process was repeated three times to obtain an ethanol suspension for recrystallization. After cooling to approximately -10°C, the precipitate was filtered, and the resulting solid was dried under reduced pressure at approximately 130°C to obtain 2.07 g of the target white solid in a yield of 45%. The synthesis scheme for this synthesis example is shown below. 【0324】 [ka] 【0325】 Furthermore, nuclear magnetic resonance spectroscopy of the white solid obtained in this synthesis example ( 1 The results of the analysis by 1H-NMR are shown below. From this, it was found that mmtBuBioFBi was successfully synthesized in this synthesis example. 【0326】 1H-NMR(CDCl3,500MHz):δ=1.29(s,6H),1.38(s,18H),6.76(dd,J1=8.0Hz,J2=2.0Hz,1H),6.87(d ,J=2.5Hz,1H),7.00-7.08(m,5H),7.18-7.23(m,3H),7.27-7.43(m,12H),7.55(d,J=7.5Hz,1H). 【0327】 Next, 2.0 g of the obtained solid was purified by sublimation using the train sublimation method. Sublimation purification was performed by heating at 225°C under conditions of a pressure of 3.77 Pa and an argon flow rate of 15.0 mL / min. After sublimation purification, 1.9 g of white solid was obtained with a recovery rate of 95%. 【0328】 Furthermore, the refractive index of mmtBuBioFBi was measured using a spectroscopic ellipsometer (M-2000U, manufactured by J.A. Woolam Japan). For the measurement, a film was used in which each layer of material was deposited on a quartz substrate by vacuum deposition, with a thickness of approximately 50 nm. 【0329】 As a result, mmtBuBioFBi was found to have a paraphotonic refractive index in the range of 1.50 to 1.75 throughout the entire blue emission region (455 nm to 465 nm), and also in the range of 1.45 to 1.70 at 633 nm, indicating that it is a material with a low refractive index. 【0330】 Next, the hole mobility of mmtBuBioFBi was calculated. The hole mobility was calculated using two methods: a simulation method based on the electrical characteristics of a measurement element that uses only holes as carriers, and a measurement method using impedance spectroscopy (IS method). 【0331】 In the IS method, a small sinusoidal voltage signal (V=V0[exp(jωt)]) is applied to an EL element, and the impedance of the EL element (Z=V / I) is determined from the phase difference between the current amplitude of the response current signal (I=I0exp[j(ωt+φ)]) and the input signal. By varying the voltage from high frequency to low frequency and applying it to the element, various components with different relaxation times that contribute to the impedance can be separated and measured. 【0332】 Here, the admittance Y (=1 / Z), which is the reciprocal of impedance, can be expressed in terms of conductance G and susceptance B as shown in equation (1) below. 【0333】 【number】 【0334】 Furthermore, equations (2) and (3) below can be calculated using the single-charge injection model. Here, g (equation (4)) is the differential conductance. In the equations, C is capacitance, θ is ωt (travel angle), and ω is angular frequency. t is travel time, and d is film thickness. The current equation, Poisson's equation, and the current continuity equation are used in the analysis, and the existence of diffusion current and trap levels is ignored. 【0335】 【number】 【0336】 The -ΔB method is a method for calculating mobility from the frequency characteristics of capacitance. The ωΔG method is another method for calculating mobility from the frequency characteristics of conductance. 【0337】 In practice, first, a measurement element is fabricated for the material whose carrier mobility is to be determined. In this embodiment, the measurement element is designed so that only holes flow as carriers. This specification describes a method for calculating mobility from the frequency characteristics of capacitance (-ΔB method). 【0338】 The table below shows the element structure of the measurement element. In the table, APC is an alloy film of silver (Ag), palladium (Pd), and copper (Cu); ITSO is indium tin oxide containing silicon oxide; OCHD-001 is an electron acceptor material; MoOx is molybdenum oxide; and Al is aluminum. The mobility of the material used in the second layer, which is formed with a film thickness of 500 nm, can be calculated. 【0339】 [Table 7] 【0340】 Figure 27 shows the current density-voltage characteristics of the measuring element. 【0341】 Impedance measurements were performed under the conditions of applying a DC voltage in the range of 5.0V to 9.0V while simultaneously applying an AC voltage of 70mV and a frequency of 1Hz to 3MHz. The capacitance was then calculated from the admittance (equation (1) above), which is the reciprocal of the impedance obtained. 【0342】 The frequency characteristics of capacitance C are obtained because the space charge due to carriers injected by a minute voltage signal cannot fully follow the minute AC voltage, resulting in a phase difference in the current. Here, the travel time of carriers in the film is defined as the time T for the injected carriers to reach the counter electrode, and is expressed by the following equation (5), where L is the film thickness. 【0343】 【number】 【0344】 The negative susceptance change (-ΔB) corresponds to the value obtained by multiplying the capacitance change (-ΔC) by the angular frequency ω (-ωΔC). Its lowest frequency peak frequency is f'. max (=ω max From equation (3), it can be derived that the following relationship (6) exists between (2π) and the travel time T. 【0345】 【number】 【0346】 The lowest frequency peak frequency f' is obtained from the frequency characteristics of -ΔB calculated from the above measurements (i.e., when the DC voltage is 7.0V). maxFrom this, the travel time T can be determined (see equation (6) above), and from equation (5) above, in this case, the hole mobility at a voltage of 7.0V can be determined. By performing similar measurements in the range of DC voltage from 5.0V to 9.0V, the hole mobility at each voltage (electric field strength) can be calculated, and thus the electric field strength dependence of the mobility can also be measured. 【0347】 Figure 28 shows the electric field strength dependence of the hole mobility of mmtBuBioFBi obtained by the calculation method described above. The hole mobility calculated by simulation is shown as a dotted line. The horizontal axis in Figure 28 represents the square root of the electric field strength converted from voltage. 【0348】 The simulation was performed using the Drift-Diffusion module of Setfos (Cybernet Systems). The simulation parameters were set as follows: a work function of 5.36 eV for the anode (ITSO), a work function of 4.2 eV for the cathode (Al), and the HOMO level of mmtBuBioFBi to -5.42 eV. The charge density in the second layer was set to 1.0 × 10⁻⁶. 18 cm -3 That's what I decided. 【0349】 The work function of the electrodes was measured in air using photoelectron spectroscopy (RIKEN Instruments, AC-2). 【0350】 The HOMO levels of organic compounds were measured by cyclic voltammetry (CV). An electrochemical analyzer (B.A.S. Corporation, model ALS Model 600A or 600C) was used for the measurements. Solutions of each compound dissolved in N,N-dimethylformamide (DMF) were measured. During the measurement, the oxidation peak potential and reduction peak potential were obtained by varying the potential of the working electrode relative to the reference electrode within an appropriate range. Furthermore, since the redox potential of the reference electrode was estimated to be -4.94 eV, the HOMO levels of each organic compound were calculated from this value and the obtained peak potentials. 【0351】 Thus, mmtBuBioFBi is 1 × 10 -3cm 2 It was found to be an organic compound with good properties, possessing a hole mobility of 1 / Vs or higher. [Examples] 【0352】 ≪Synthesis Example 2≫ This synthesis example describes the synthesis method for N,N-bis(4-cyclohexylphenyl)-9,9,-dimethyl-9H-fluoren-2-amine (abbreviated as dchPAF), an organic compound according to one embodiment of the present invention used in the examples. The structure of dchPAF is shown below. 【0353】 [ka] 【0354】 <Step 1: Synthesis of N,N-bis(4-cyclohexylphenyl)-9,9,-dimethyl-9H-fluoren-2-amine (abbreviation: dchPAF)> 10.6 g (51 mmol) of 9,9-dimethyl-9H-fluoren-2-amine, 18.2 g (76 mmol) of 4-cyclohexyl-1-bromobenzene, 21.9 g (228 mmol) of sodium tert-butoxide, and 255 mL of xylene were placed in a three-necked flask. After degassing under reduced pressure, the flask was purged with nitrogen. This mixture was heated and stirred to approximately 50°C. Then, 370 mg (1.0 mmol) of allyl palladium chloride dimer(II) (abbreviation: [(Allyl)PdCl]2) and 1660 mg (4.0 mmol) of di-tert-butyl (1-methyl-2,2-diphenylcyclopropyl)phosphine (abbreviation: cBRIDP®) were added, and this mixture was heated at 120°C for approximately 5 hours. After that, the flask temperature was reduced to approximately 60°C, and approximately 4 mL of water was added to precipitate a solid. The precipitated solid was filtered off. The filtrate was concentrated, and the resulting solution was purified by silica gel column chromatography. The resulting solution was concentrated to obtain a concentrated toluene solution. This toluene solution was added dropwise to ethanol and reprecipitation occurred. The precipitate was filtered at approximately 10°C, and the resulting solid was dried under reduced pressure at approximately 80°C to obtain 10.1 g of the target white solid in a yield of 40%. The synthesis scheme for Step 1 is shown below. 【0355】 [ka] 【0356】 Furthermore, nuclear magnetic resonance spectroscopy of the white solid obtained in step 1 above ( 1 The results of the analysis by 1H-NMR are shown below. This confirms that dchPAF was successfully synthesized in this synthesis example. 【0357】 1H-NMR.δ(CDCl3):7.60(d,1H,J=7.5Hz),7.53(d,1H,J=8.0Hz),7.37(d,2H,J=7 .5Hz),7.29(td,1H,J=7.5Hz,1.0Hz),7.23(td,1H,J=7.5Hz,1.0Hz),7.19(d,1H ,J=1.5Hz),7.06(m,8H),6.97(dd,1H,J=8.0Hz,1.5Hz),2.41-2.51(brm,2H),1. 79-1.95(m,8H),1.70-1.77(m,2H),1.33-1.45(brm,14H),1.19-1.30(brm,2H). 【0358】 Next, 5.6 g of the obtained solid was purified by sublimation using the train sublimation method. Sublimation purification was performed by heating at 215°C under conditions of a pressure of 3.0 Pa and an argon flow rate of 12.0 mL / min. After sublimation purification, 5.2 g of a slightly yellowish-white solid was obtained with a recovery rate of 94%. 【0359】 Furthermore, the refractive index of dchPAF was measured using a spectroscopic ellipsometer (M-2000U, manufactured by J.A. Woolam Japan). For the measurement, a film was used in which each layer of material was deposited on a quartz substrate by vacuum deposition, with a thickness of approximately 50 nm. 【0360】 As a result, it was found that dchPAF has a paraphotonic refractive index in the range of 1.50 to 1.75 throughout the entire blue emission region (455 nm to 465 nm), and also has a paraphotonic refractive index in the range of 1.45 to 1.70 at 633 nm, indicating that it is a material with a low refractive index. [Examples] 【0361】 ≪Synthesis Example 3≫ This synthesis example describes the synthesis method of N-[(3',5'-ditterybutyl)-1,1'-biphenyl-4-yl]-N-(4-cyclohexylphenyl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as mmtBuBichPAF), an organic compound according to one embodiment of the present invention used in the examples. The structure of mmtBuBichPAF is shown below. 【0362】 [ka] 【0363】 <Step 1: Synthesis of 3',5'-Ditter-butyl-4-chloro-1,1'-biphenyl> 13.5 g (50 mmol) of 3,5-diter-butyl-1-bromobenzene, 8.2 g (52.5 mmol) of 4-chlorophenylboronic acid, 21.8 g (158 mmol) of potassium carbonate, 125 mL of toluene, 31 mL of ethanol, and 40 mL of water were placed in a three-necked flask. After degassing under reduced pressure, the flask was purged with nitrogen. 225 mg (1.0 mmol) of palladium acetate and 680 mg (2.0 mmol) of tris(2-methylphenyl)phosphine (abbreviation: P(o-Tol)3) were added to this mixture, and the mixture was heated under reflux at 80°C for approximately 3 hours. After returning to room temperature, the organic and aqueous layers were separated. Magnesium sulfate was added to the solution to dry it, and the solution was concentrated. The resulting solution was purified by silica gel column chromatography. The resulting solution was concentrated and allowed to dry. Hexane was then added and recrystallized. The mixed solution, which precipitated as a white solid, was cooled on ice and then filtered. The obtained solid was vacuum-dried at approximately 60°C to obtain 9.5 g of the target white solid in a yield of 63%. The synthesis scheme for Step 1 is shown in the following equation. 【0364】 [ka] 【0365】 <Step 2: Synthesis of N-(4-cyclohexylphenyl)-N-(9,9-dimethyl-9H-fluoren-2yl)amine> 10.5 g (50 mmol) of 9,9-dimethyl-9H-fluoren-2-amine, 12.0 g (50 mmol) of 4-cyclohexyl-1-bromobenzene, 14.4 g (150 mmol) of sodium tert-butoxide, and 250 mL of xylene were placed in a three-necked flask. After degassing under reduced pressure, the flask was purged with nitrogen. This mixture was heated and stirred to approximately 50°C. Then, 183 mg (0.50 mmol) of allyl palladium chloride dimer(II) (abbreviation: [(Allyl)PdCl]2) and 821 mg (2.0 mmol) of di-tert-butyl (1-methyl-2,2-diphenylcyclopropyl)phosphine (abbreviation: cBRIDP®) were added, and this mixture was heated at 90°C for approximately 6 hours. After that, the temperature of the flask was lowered to approximately 60°C, approximately 4 mL of water was added, and the precipitated solid was filtered off. The filtrate was concentrated, and the resulting solution was purified by silica gel column chromatography. The obtained solution was concentrated to obtain a concentrated toluene solution. This toluene solution was dried under vacuum at approximately 60°C to obtain 17.3 g of the target product, a brownish oily substance, in a yield of 92%. The synthesis scheme for Step 2 is shown in the following equation. 【0366】 [ka] 【0367】 <Step 3: Synthesis of N-[(3',5'-Ditter-butyl)-1,1'-Biphenyl-4-yl]-N-(4-Cyclohexylphenyl)-9,9-Dimethyl-9H-Fluorene-2-amine (abbreviation: mmtBuBichPAF)> 3.2 g (10.6 mmol) of 3',5'-diter-butyl-4-chloro-1,1'-biphenyl obtained in Step 1, 3.9 g (10.6 mmol) of N-(4-cyclohexylphenyl)-N-(9,9-dimethyl-9H-fluoren-2yl)amine obtained in Step 2, 3.1 g (31.8 mmol) of sodium tert-butoxide, and 53 mL of xylene were placed in a three-necked flask. After degassing under reduced pressure, the flask was purged with nitrogen. This mixture was heated and stirred to approximately 50°C. Here, 39 mg (0.11 mmol) of allyl palladium chloride dimer(II) (abbreviated as [(Allyl)PdCl]2) and 150 mg (0.42 mmol) of di-tert-butyl (1-methyl-2,2-diphenylcyclopropyl)phosphine (abbreviated as cBRIDP®) were added, and this mixture was heated at 120°C for about 3 hours. After that, the temperature of the flask was returned to about 60°C, and about 1 mL of water was added to precipitate the solid. The precipitated solid was filtered off. The filtrate was concentrated, and the resulting solution was purified by silica gel column chromatography. The resulting solution was concentrated to obtain a concentrated toluene solution. Ethanol was added to this toluene solution, and it was concentrated under reduced pressure to obtain an ethanol suspension. The precipitated solid at about 20°C was filtered, and the obtained solid was dried under reduced pressure at about 80°C to obtain 5.8 g of the target white solid in a yield of 87%. The synthesis scheme for Step 3 is shown in the following formula. 【0368】 [ka] 【0369】 Furthermore, nuclear magnetic resonance spectroscopy of the white solid obtained in step 3 above ( 1 The results of the analysis by 1H-NMR are shown below. This shows that N-[(3',5'-ditter-butyl)-1,1'-biphenyl-4-yl]-N-(4-cyclohexylphenyl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: mmtBuBichPAF) was successfully synthesized in this synthesis example. 【0370】 1H-NMR.δ(CDCl3):7.63(d,1H,J=7.5Hz),7.57(d,1H,J=8.0Hz),7.44-7.49(m,2H) ,7.37-7.42(m,4H),7.31(td,1H,J=7.5Hz,2.0Hz),7.23-7.27(m,2H),7.15-7.19( m,2H),7.08-7.14(m,4H),7.05(dd,1H,J=8.0Hz,2.0Hz),2.43-2.53(brm,1H),1. 81-1.96(m,4H),1.75(d,1H,J=12.5Hz),1.32-1.48(m,28H),1.20-1.31(brm,1H). 【0371】 Next, 3.5 g of the obtained solid was purified by sublimation using the train sublimation method. Sublimation purification was performed by heating at 255°C under conditions of a pressure of 3.0 Pa and an argon flow rate of 11.8 mL / min. After sublimation purification, 3.1 g of a slightly yellowish-white solid was obtained with a recovery rate of 89%. 【0372】 Furthermore, the refractive index of mmtBuBichPAF was measured using a spectroscopic ellipsometer (M-2000U, manufactured by J.A. Woolam Japan). For the measurement, a film was used in which each layer of material was deposited on a quartz substrate by vacuum deposition, with a thickness of approximately 50 nm. 【0373】 As a result, mmtBuBichPAF was found to have a paraphotonic refractive index in the range of 1.50 to 1.75 throughout the entire blue emission region (455 nm to 465 nm), and also in the range of 1.45 to 1.70 at 633 nm, indicating that it is a material with a low refractive index. [Examples] 【0374】 This embodiment describes in detail a light-emitting device using an organic compound according to one aspect of the present invention. The structural formulas of representative organic compounds used in this embodiment are shown below. 【0375】 [ka] 【0376】 (Method for fabricating the light-emitting device 20) First, a 100 nm thin film of silver (Ag) was deposited on a glass substrate to form a reflective electrode. Then, a film of indium tin oxide (ITSO) containing silicon dioxide was deposited by sputtering to form the first electrode 101. The film thickness was 10 nm, and the electrode area was 2 mm × 2 mm. 【0377】 Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water, baked at 200°C for 1 hour, and then subjected to UV ozone treatment for 370 seconds. 【0378】 Then, 10 -4 The substrate was introduced into a vacuum deposition apparatus where the internal pressure was reduced to approximately Pa. After vacuum firing at 170°C for 30 minutes in the heating chamber of the vacuum deposition apparatus, the substrate was allowed to cool for about 30 minutes. 【0379】 Next, the substrate on which the first electrode 101 is formed is fixed to a substrate holder provided in a vacuum deposition apparatus so that the surface on which the first electrode 101 is formed faces downwards. Then, a hole injection layer 111 is formed on the first electrode 101 by co-depositing a low refractive index organic compound (low-n HTM) and an electron acceptor material (OCHD-001) at a weight ratio of 1:0.1 (=low-n HTM:OCHD-001) to a thickness of 10 nm using a deposition method with resistance heating. 【0380】 The low-n HTM used was N-3',5'-ditterybutyl-1,1'-biphenyl-4-yl-N-1,1'-biphenyl-2-yl-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: mmtBuBioFBi), represented by the above structural formula (i). 【0381】 Next, mmtBuBioFBi was deposited on the hole injection layer 111 to a thickness of 120 nm to form a hole transport layer 112. Then, 10 nm of N-[4-(9Hcarbazole-9-yl)phenyl]-N-[4-(4-dibenzofuranyl)phenyl]-[1,1':4',1''-terphenyl]-4-amine (abbreviated as YGTPDBfB), represented by the above structural formula (xiv), was deposited to form an electron blocking layer. 【0382】 Next, 2-(10-phenyl-9-anthracenyl)-benzo[b]naphtho[2,3-d]furan (abbreviated as Bnf(II)PhA), represented by the above structural formula (xv), and 3,10-bis[N-(9-phenyl-9H-carbazole-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviated as 3,10PCA2Nbf(IV)-02), represented by the above structural formula (x), were co-deposited in a weight ratio of 1:0.015 (=Bnf(II)PhA:3,10PCA2Nbf(IV)-02) to a film thickness of 25 nm to form an emissive layer 113. 【0383】 Subsequently, a hole-blocking layer was formed on the light-emitting layer 113 by depositing 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)-1,1'-biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviated as mFBPTzn), represented by the above structural formula (xvi), to a thickness of 10 nm. 【0384】 An electron transport layer 114 was formed on the hole block layer by co-depositing 2-[3-(2,6-dimethyl-3-pyridinyl)-5-(9-phenantrenyl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviated as mPn-mDMePyPTzn), represented by the above structural formula (xvii), and 8-quinolinolato-lithium (abbreviated as Liq), represented by the above structural formula (xii), in a weight ratio of 1:1 (=mPn-mDMePyPTzn:Liq) and with a film thickness of 25 nm. 【0385】 After forming the electron transport layer 114, lithium fluoride (LiF) was deposited at a depth of 1 nm to form the electron injection layer 115. Subsequently, silver (Ag) and magnesium (Mg) were co-deposited at a volume ratio of 10:1 (=Ag:Mg) at a depth of 15 nm to form the second electrode 102 and create the light-emitting device 20. The second electrode 102 is translucent, and the light-emitting device 20 is a top-emission type light-emitting device that extracts light from the second electrode side. Furthermore, a 70 nm film of 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), represented by the above structural formula (xviii), was deposited on the second electrode 102 to improve the extraction efficiency. 【0386】 (Method for fabricating the comparative light-emitting device 20) Comparative light-emitting device 20 was fabricated in the same manner as light-emitting device 20, except that mmtBuBioFBi in light-emitting device 20 was replaced with N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as PCBBiF), represented by the above structural formula (xiii). 【0387】 The element structures of the above-mentioned light-emitting device 20 and comparative light-emitting device 20 are summarized in the table below. 【0388】 [Table 8] 【0389】 [Table 9] 【0390】 Furthermore, the ordinary refractive index n of the low-n HTM vapor-deposited film used in the hole injection layer and hole transport layer, and the comparative material PCBBiF vapor-deposited film o The birefringence Δn and orientation order parameter S are shown in the table below. 【0391】 [Table 10] 【0392】 The above-mentioned light-emitting device and comparative light-emitting device were sealed with a glass substrate in a glove box under a nitrogen atmosphere to prevent exposure to the atmosphere (sealing material was applied around the element, UV treatment was performed during sealing, and heat treatment was performed at 80°C for 1 hour). After this, the initial characteristics of these light-emitting devices were measured. 【0393】 Figure 29 shows the luminance-current density characteristics of the light-emitting device 20 and the comparative light-emitting device 20, Figure 30 shows the luminance-voltage characteristics, Figure 31 shows the current efficiency-luminance characteristics, Figure 32 shows the current density-voltage characteristics, Figure 33 shows the blue index-luminance characteristics, and Figure 34 shows the emission spectra of each light-emitting device at 1000 cd / m². 2 Table 11 shows the main characteristics in the vicinity. A spectroradiometer (Topcon UR-UL1R) was used to measure luminance, CIE chromaticity, and emission spectrum at room temperature. The Blue Index (BI) is the value obtained by dividing the current efficiency (cd / A) by the y-chromaticity, and is one of the indicators that represent the emission characteristics of blue light. Blue light tends to have higher color purity as the y-chromaticity decreases. High-color-purity blue light can express a wide range of blue colors even with a small luminance component, and by using high-color-purity blue light, the required luminance to express blue decreases, resulting in a reduction in power consumption. Therefore, BI, which takes into account y-chromaticity, one of the indicators of blue purity, is suitably used as a means of representing the efficiency of blue light, and it can be said that light-emitting devices with a high BI are more efficient as blue light-emitting devices used in displays. 【0394】 [Table 11] 【0395】 As can be seen from Figures 29 to 34, the light-emitting device 20 according to one embodiment of the present invention exhibits a driving voltage equivalent to that of the comparative light-emitting device 20, but by using a low refractive index organic compound in the hole injection layer and hole transport layer, it is a light-emitting device with significantly improved blue index, luminous efficiency and chromaticity. Therefore, the light-emitting device according to one embodiment of the present invention is a light-emitting device with low power consumption. 【0396】 Furthermore, the current density of the light-emitting device 20 and the comparative light-emitting device 20 is 50 mA / cm². 2 Figure 35 shows a graph representing the change in brightness with respect to operating time. As shown in Figure 35, it was also found that the light-emitting device 20, which is a light-emitting device according to one aspect of the present invention, has a better lifespan compared to the comparative light-emitting device 20. [Examples] 【0397】 This example describes in detail a light-emitting device and a comparative light-emitting device using an organic compound according to one embodiment of the present invention. The structural formulas of representative organic compounds used in this example are shown below. 【0398】 [ka] 【0399】 (Method for fabricating the light-emitting device 30) First, a 100 nm thin film of silver (Ag) was deposited on a glass substrate to form a reflective electrode. Then, a film of indium tin oxide (ITSO) containing silicon dioxide was deposited by sputtering to form the first electrode 101. The film thickness was 10 nm, and the electrode area was 2 mm × 2 mm. 【0400】 Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water, baked at 200°C for 1 hour, and then subjected to UV ozone treatment for 370 seconds. 【0401】 Then, 10 -4The substrate was introduced into a vacuum deposition apparatus where the internal pressure was reduced to approximately Pa. After vacuum firing at 170°C for 30 minutes in the heating chamber of the vacuum deposition apparatus, the substrate was allowed to cool for about 30 minutes. 【0402】 Next, the substrate on which the first electrode 101 is formed is fixed to a substrate holder provided in a vacuum deposition apparatus so that the surface on which the first electrode 101 is formed faces downwards. Then, a hole injection layer 111 is formed on the first electrode 101 by co-depositing a low refractive index organic compound (low-n HTM) and an electron acceptor material (OCHD-001) at a weight ratio of 1:0.1 (=low-n HTM:OCHD-001) to a thickness of 10 nm using a deposition method with resistance heating. 【0403】 The low-n HTM used was N-3',5'-ditterybutyl-1,1'-biphenyl-4-yl-N-1,1'-biphenyl-2-yl-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: mmtBuBioFBi), represented by the above structural formula (i). 【0404】 Next, mmtBuBioFBi was deposited on the hole injection layer 111 to a thickness of 125 nm to form a hole transport layer 112, and N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviated as DBfBB1TP), represented by the above structural formula (viii), was deposited to a thickness of 10 nm to form an electron blocking layer. 【0405】 Next, 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviated as αN-βNPAnth), represented by the above structural formula (ix), and 3,10-bis[N-(9-phenyl-9H-carbazole-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviated as 3,10PCA2Nbf(IV)-02), represented by the above structural formula (x), were co-deposited in a weight ratio of 1:0.015 (=αN-βNPAnth:3,10PCA2Nbf(IV)-02) to a film thickness of 20 nm to form the light-emitting layer 113. 【0406】 Subsequently, a hole blocking layer was formed on the light-emitting layer 113 by depositing 6-(1,1'-biphenyl-3-yl)-4-[3,5-bis(9H-carbazole-9-yl)phenyl]-2-phenylpyrimidine (abbreviated as 6mBP-4Cz2PPm), represented by the above structural formula (xix), to a thickness of 10 nm. Then, an electron transport layer 114 was formed by co-depositing 2-[3-(2,6-dimethyl-3-pyridinyl)-5-(9-phenantrenyl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviated as mPn-mDMePyPTzn), represented by the above structural formula (xvii), and 8-quinolinolato-lithium (abbreviated as Liq), represented by the above structural formula (xii), in a weight ratio of 1:1 (=mPn-mDMePyPTzn:Liq) to a film thickness of 20 nm. 【0407】 After forming the electron transport layer 114, lithium fluoride (LiF) was deposited at a depth of 1 nm to form the electron injection layer 115. Silver (Ag) and magnesium (Mg) were co-deposited at a volume ratio of 10:1 (=Ag:Mg) at a depth of 15 nm to form the second electrode 102 and create the light-emitting device 30. The second electrode 102 is translucent, and the light-emitting device 30 is a top-emission type light-emitting device that extracts light from the second electrode side. Furthermore, a 70 nm film of 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), represented by the above structural formula (xviii), was deposited on the second electrode 102 to improve the extraction efficiency. 【0408】 (Method for fabricating the light-emitting device 31) Light-emitting device 31 was fabricated in the same manner as light-emitting device 30, except that mPn-mDMePyPTzn in light-emitting device 30 was replaced with 2-{(3',5'-di-tert-butyl)-1,1'-biphenyl-3-yl}-4,6-diphenyl-1,3,5-triazine (abbreviated as mmtBumBPTzn) represented by the above structural formula (xx), and Liq was replaced with 6-methyl-8-quinolinolato-lithium (abbreviated as Li-6mq) represented by the above structural formula (xxi). 【0409】 (Method for fabricating the comparative light-emitting device 30) Comparative light-emitting device 30 was fabricated in the same manner as light-emitting device 31, except that mmtBuBioFBi in light-emitting device 31 was replaced with N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as PCBBiF), represented by the above structural formula (xiii), and the thickness of the hole transport layer was set to 115 nm. 【0410】 (Method for fabricating the comparative light-emitting device 31) Comparative light-emitting device 31 was fabricated in the same manner as light-emitting device 30, except that mmtBuBioFBi was replaced with PCBBiF and the thickness of the hole transport layer was set to 115 nm. 【0411】 The element structures of the above-mentioned light-emitting device and the comparative light-emitting device are summarized in the table below. 【0412】 [Table 12] 【0413】 [Table 13] 【0414】 Furthermore, the ordinary refractive index n of the low-n HTM vapor-deposited film used in the hole injection layer and hole transport layer, and the comparative material PCBBiF vapor-deposited film o The birefringence Δn and orientation order parameter S are shown in the table below. 【0415】 [Table 14] 【0416】 The above-mentioned light-emitting devices and comparative light-emitting devices were sealed with glass substrates in a glove box under a nitrogen atmosphere to prevent exposure to the atmosphere (sealant was applied around the elements, UV treatment was performed during sealing, and heat treatment was performed at 80°C for 1 hour). After this, the initial characteristics of these light-emitting devices were measured. No special measures were taken to improve the removal efficiency of the glass substrates on which the light-emitting devices were fabricated. 【0417】 Figure 36 shows the luminance-current density characteristics of light-emitting device 30, light-emitting device 31, and comparative light-emitting device 30 and comparative light-emitting device 31; Figure 37 shows the luminance-voltage characteristics; Figure 38 shows the current efficiency-luminance characteristics; Figure 39 shows the current density-voltage characteristics; Figure 40 shows the blue index-luminance characteristics; and Figure 41 shows the emission spectra of each light-emitting device at 1000 cd / m². 2 Table 15 shows the main characteristics of the vicinity. Luminance, CIE chromaticity, and emission spectrum were measured using a spectroradiometer (Topcon UR-UL1R) at room temperature. 【0418】 [Table 15] 【0419】 Figures 36 to 41 show that the light-emitting device according to one embodiment of the present invention is a light-emitting device with good luminous efficiency, exhibiting a significantly improved blue index compared to the comparative light-emitting device, due to the use of low refractive index organic compounds in the hole injection layer and hole transport layer. Therefore, the light-emitting device according to one embodiment of the present invention can be said to be a light-emitting device with low power consumption. Note that mmtBumBPTzn and Li-6mq, used in the electron transport layer of light-emitting device 31 and comparative light-emitting device 30, are materials with lower refractive indices compared to PCBBiF and Liq, used in light-emitting device 30 and comparative light-emitting device 31. 【0420】 Furthermore, the current density of the light-emitting device 30, light-emitting device 31, comparison light-emitting device 30, and comparison light-emitting device 31 is 50 mA / cm². 2Figure 42 shows a graph representing the change in brightness with respect to operating time. As shown in Figure 42, it was also found that the light-emitting devices 30 and 31, which are light-emitting devices according to one aspect of the present invention, are light-emitting devices with a good lifespan. 【0421】 <Reference example> ≪Reference synthesis example 1≫ This example describes the synthesis method of N-(3,5-ditterbutylphenyl)-N-(3',5',-ditterbutyl-1,1'-biphenyl-4-yl)-9,9,-dimethyl-9H-fluoren-2-amine (abbreviated as mmtBuBimmtBuPAF), which was used as a low refractive index organic compound in Example 1. The structure of mmtBuBimmtBuPAF is shown below. 【0422】 [ka] 【0423】 <Step 1: Synthesis of 3',5'-Ditter-butyl-4-chloro-1,1'-biphenyl> The synthesis was carried out in the same manner as in step 1 of synthesis example 3 in Example 3. 【0424】 <Step 2: Synthesis of N-(3',5'-ditter-butyl-1,1'-biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)amine> 2.8 g (13.5 mmol) of 9,9-dimethyl-9H-fluoren-2-amine, 6.1 g (20.3 mmol) of 3',5'-diter-butyl-4-chloro-1,1'-biphenyl obtained in Step 1, 5.8 g (60.8 mmol) of sodium tert-butoxide, and 70 mL of xylene were placed in a three-necked flask. After degassing under reduced pressure, the flask was purged with nitrogen. This mixture was heated and stirred to approximately 50°C. Then, 100 mg (0.27 mmol) of allyl palladium chloride dimer(II) (abbreviation: [(Allyl)PdCl]2) and 381 mg (1.08 mmol) of di-tert-butyl (1-methyl-2,2-diphenylcyclopropyl)phosphine (abbreviation: cBRIDP®) were added, and the mixture was heated at 120°C for approximately 3 hours. Subsequently, the flask temperature was returned to approximately 60°C, approximately 1 mL of water was added, and the precipitated solid was filtered off. The filtrate was concentrated, and the resulting solution was purified by silica gel column chromatography. The obtained solution was concentrated to obtain a concentrated toluene solution. Ethanol was added to this toluene solution, and it was concentrated under reduced pressure to obtain an ethanol suspension. The precipitate was filtered at approximately 20°C, and the resulting solid was dried under reduced pressure at approximately 80°C to obtain 2.9 g of N-(3',5'-ditterybutyl-1,1'-biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)amine as a brownish oily substance in 46% yield. The synthesis scheme for Step 2 is shown in the following formula. 【0425】 [ka] 【0426】 <Step 3: Synthesis of N-(3,5-diter-butylphenyl)-N-(3',5'-diter-butyl-1,1'-biphenyl-4-yl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: mmtBuBimmtBuPAF)> In a three-necked flask, 2.7 g (5.7 mmol) of N-(3',5'-ditterbutyl-1,1'-biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)amine, 1.5 g (5.7 mmol) of 3,5-ditterbutyl-1-bromobenzene, 1.6 g (17.0 mmol) of sodium tert-butoxide, and 30 mL of xylene were placed. The mixture was degassed under reduced pressure, and then the flask was purged with nitrogen. The mixture was heated and stirred to approximately 50°C. Here, 21 mg (0.057 mmol) of allyl palladium chloride dimer(II) (abbreviated as [(Allyl)PdCl]2) and 73 mg (0.208 mmol) of di-tert-butyl (1-methyl-2,2-diphenylcyclopropyl)phosphine (abbreviated as cBRIDP®) were added, and the mixture was heated at 120°C for approximately 7 hours. After that, the flask temperature was reduced to approximately 60°C, approximately 1 mL of water was added, and the precipitated solid was filtered off. The filtrate was concentrated, and the resulting solution was purified by silica gel column chromatography. The resulting solution was concentrated to obtain a concentrated toluene solution. Ethanol was added to this toluene solution, and the mixture was concentrated under reduced pressure to obtain an ethanol suspension. The precipitate was filtered at approximately 20°C, and the resulting solid was dried under reduced pressure at approximately 80°C to obtain 3.6 g of the target white solid in a yield of 95%. The synthesis scheme for Step 3 is shown in the following equation. 【0427】 [ka] 【0428】 Furthermore, nuclear magnetic resonance spectroscopy of the white solid obtained in step 3 ( 1 The results of the analysis by 1H-NMR are shown below. This shows that N-(3,5-ditterbutylphenyl)-N-(3',5'-ditterbutyl-1,1'-biphenyl-4-yl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: mmtBuBimmtBuPAF) was synthesized in this synthesis example. 【0429】 1H-NMR.δ(CDCl3):7.64(d,1H,J=7.5Hz),7.57(d,1H,J=8.0Hz),7.48(d,2H,J=8.0Hz),7.43(m,2H),7.39(m,2H) ,7.31(td,1H,J=6.0Hz,1.5Hz),7.15-7.25(m,4H),6.97-7.02(m,4H),1.42(s,6H),1.38(s,18H),1.25(s,18H). 【0430】 Next, 3.2 g of the obtained solid was purified by sublimation using the train sublimation method. Sublimation purification was performed by heating at 210°C under conditions of a pressure of 3.0 Pa and an argon flow rate of 19.3 mL / min. After sublimation purification, 3.0 g of a slightly yellowish-white solid was obtained with a recovery rate of 94%. 【0431】 Furthermore, the refractive index of mmtBuBimmtBuPAF was measured using a spectroscopic ellipsometer (M-2000U, manufactured by J.A. Woolam Japan). For the measurement, a film was used in which each layer of material was deposited on a quartz substrate by vacuum deposition, with a thickness of approximately 50 nm. 【0432】 As a result, mmtBuBimmtBuPAF was found to have a paraphotonic refractive index in the range of 1.50 to 1.75 throughout the entire blue emission region (455 nm to 465 nm), and also in the range of 1.45 to 1.70 at 633 nm, indicating that it is a material with a low refractive index. 【0433】 ≪Reference synthesis example 2≫ This example describes the synthesis method of N-(3,3'',5,5''-tetra-t-butyl-1,1':3',1''-terphenyl-5'-yl)-N-(4-cyclohexylphenyl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as mmtBumTPchPAF), which was used as a low refractive index organic compound in Example 1. The structure of mmtBumTPchPAF is shown below. 【0434】 [ka] 【0435】 <Step 1: Synthesis of 3,3'',5,5''-tetra-t-butyl-5'-chloro-1,1':3',1''-terphenyl> In a three-necked flask, 1.66 g (6.14 mmol) of 1,3-dibromo-5-chlorobenzene, 4.27 g (13.5 mmol) of 2-(3,5-di-t-butylphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, 187 mg (0.614 mmol) of tris(2-methylphenyl)phosphine (abbreviation: P(o-tolyl)3), 13.5 mL of 2M potassium carbonate aqueous solution, 20 mL of toluene, and 10 mL of ethanol were added. The mixture was stirred under reduced pressure to degass it, and then purged with nitrogen. 27.5 mg (0.122 mmol) of palladium(II) acetate was added to this mixture, and the mixture was stirred under a nitrogen stream at 80°C for approximately 4 hours. After stirring, water was added to the mixture to separate it into an organic layer and an aqueous layer. The aqueous layer was extracted with toluene. The obtained extract and the organic layer were combined, washed with water and saturated brine, and then dried over magnesium sulfate. This mixture was filtered by natural filtration, and the filtrate was concentrated to obtain a yellow oily substance. This oily substance was purified by silica gel column chromatography. The resulting fraction was concentrated to obtain the target product, a white solid, in a yield of 2.98 g and 99%. The synthesis scheme for Step 1 is shown in the following equation. 【0436】 [ka] 【0437】 Furthermore, nuclear magnetic resonance spectroscopy of the white solid obtained in step 1 above ( 1 The results of the analysis by 1H-NMR are shown below. This shows that the organic compound, 3,3'',5,5''-tetra-t-butyl-5'-chloro-1,1':3',1''-terphenyl, was synthesized in Step 1. 【0438】 1 H-NMR (300MHz, CDCl3): δ=7.63-7.64(m,1H),7.52-7.47(m,4H),7.44-7.40(m,4H),1.38(s,36H). 【0439】 <Step 2: Synthesis of N-(4-cyclohexylphenyl)-N-(9,9-dimethyl-9H-fluoren-2yl)amine> The synthesis was carried out in the same manner as in step 2 of synthesis example 3 of Example 3. 【0440】 <Step 3: Synthesis of N-(3,3'',5,5''-tetra-t-butyl-1,1':3',1''-terphenyl-5'-yl)-N-(4-cyclohexylphenyl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: mmtBumTPchPAF)> 2.69 g (7.32 mmol) of N-(4-cyclohexylphenyl)-N-(9,9-dimethyl-9H-fluoren-2yl)amine obtained in Step 2, 2.98 g (6.09 mmol) of 3,3'', 5,5''-tetra-t-butyl-5'-chloro-1,1':3',1''-terphenyl obtained in Step 1, 0.103 g (0.292 mmol) of di-tert-butyl(1-methyl-2,2-diphenylcyclopropyl)phosphine (abbreviation: cBRIDP®), 1.76 g (18.3 mmol) of sodium-tert-butoxide, and 30 mL of xylene were added to a three-necked flask. The mixture was then stirred under reduced pressure to degass it, followed by nitrogen purging. 26.7 mg (0.0730 mmol) of allyl palladium chloride dimer(II) (abbreviation: [(Allyl)PdCl]2) was added to this mixture and stirred at 120°C for approximately 10 hours under a nitrogen stream. After stirring, water was added to the mixture and separated into an organic layer and an aqueous layer. The obtained aqueous layer was extracted with toluene. The obtained extract and the organic layer were combined, washed with water and saturated brine, and dried over magnesium sulfate. This mixture was filtered by natural filtration, and the filtrate was concentrated to obtain a black oily substance. This oily substance was purified by silica gel column chromatography. The obtained fraction was concentrated to obtain a pale yellow oily substance. This oily substance was purified by high-performance liquid column chromatography (eluent: chloroform). The obtained fraction was concentrated to obtain a white solid. Ethanol was added to this solid and sonication was irradiated, and the solid was collected by suction filtration to obtain the target white solid in a yield of 3.36 g and 67%. The synthesis scheme for Step 3 is shown in the following equation. 【0441】 [ka] 【0442】 The obtained white solid (3.36 g) was purified by sublimation using the train sublimation method. Sublimation purification was performed by heating the white solid at 240°C under conditions of a pressure of 5.0 Pa and an argon flow rate of 10 mL / min. After sublimation purification, a colorless, transparent, glassy solid was obtained in yield of 1.75 g and with a recovery rate of 52%. 【0443】 Furthermore, nuclear magnetic resonance spectroscopy of the white solid obtained in step 3 above ( 1 The results of the analysis by 1H-NMR are shown below. This shows that the organic compound N-(3,3'',5,5''-tetra-t-butyl-1,1':3',1''-terphenyl-5'-yl)-N-(4-cyclohexylphenyl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: mmtBumTPchPAF) was synthesized in this synthesis example. 【0444】 1 H-NMR (300MHz, CDCl3): δ=7.63(d,J=6.6Hz,1H),7.58(d,J=8.1Hz,1H),7.4 2-7.37(m,4H),7.36-7.09(m,14H),2.55-2.39(m,1H),1.98-1.20(m,51H). 【0445】 Furthermore, the refractive index of mmtBumTPchPAF was measured using a spectroscopic ellipsometer (M-2000U, manufactured by J.A. Woolam Japan). For the measurement, a film was used in which each layer of material was deposited on a quartz substrate by vacuum deposition, with a thickness of approximately 50 nm. 【0446】 As a result, mmtBumTPchPAF was found to have a paraphotonic refractive index in the range of 1.50 to 1.75 throughout the entire blue emission region (455 nm to 465 nm), and also in the range of 1.45 to 1.70 at 633 nm, indicating that it is a material with a low refractive index. 【0447】 ≪Reference synthesis example 3≫ This example describes the synthesis method of N-(1,1'-biphenyl-2-yl)-N-(3,3'',5',5''-tetra-tert-butyl-1,1':3',1''-terphenyl-5-yl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as mmtBumTPoFBi-02), which was used as a low refractive index organic compound in Example 1. The structure of mmtBumTPoFBi-02 is shown below. 【0448】 [ka] 【0449】 <Step 1: Synthesis of 3-bromo-3',5,5'-tri-tert-butylbiphenyl> 37.2 g (128 mmol) of 1,3-dibromo-5-tert-butylbenzene, 20.0 g (85 mmol) of 3,5-di-tert-butylphenylboronic acid, 35.0 g (255 mmol) of potassium carbonate, 570 mL of toluene, 170 mL of ethanol, and 130 mL of tap water were placed in a three-necked flask. After degassing under reduced pressure, the flask was purged with nitrogen, and 382 mg (1.7 mmol) of palladium acetate and 901 mg (3.4 mmol) of triphenylphosphine were added. The mixture was heated at 40°C for approximately 5 hours. After returning to room temperature, the organic layer and aqueous layer were separated. Magnesium sulfate was added to the organic layer to remove water and concentrate the solution. The resulting solution was purified by silica gel column chromatography to obtain 21.5 g of the target product, a colorless oil, in a yield of 63%. The synthesis scheme for Step 1 is shown in the following equation. 【0450】 [ka] 【0451】 <Step 2: Synthesis of 2-(3',5,5'-tri-tert-butyl[1,1'-biphenyl]-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane> In a three-necked flask, 15.0 g (38 mmol) of 3-bromo-3',5,5'-tert-butylbiphenyl obtained in Step 1, 10.5 g (41 mmol) of 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi-1,3,2-dioxaborolane, 11.0 g (113 mmol) of potassium acetate, and 125 mL of N,N-dimethylformamide were placed. After degassing under reduced pressure, the flask was purged with nitrogen, and 1.5 g (1.9 mmol) of [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (abbreviation: Pd(dppf)Cl2) was added. The mixture was heated at 100°C for approximately 3 hours. After returning to room temperature, the organic and aqueous layers were separated and extracted with ethyl acetate. Magnesium sulfate was added to this extract to remove water and concentrate it. The toluene solution of the obtained mixture was purified by silica gel column chromatography, and the resulting solution was concentrated to obtain a concentrated toluene solution. Ethanol was added to this toluene solution, and it was concentrated under reduced pressure to obtain an ethanol suspension. The precipitate was filtered at approximately 20°C, and the resulting solid was dried under reduced pressure at approximately 80°C to obtain 13.6 g of the target white solid in a yield of 81%. The synthesis scheme for Step 2 is shown in the following equation. 【0452】 [ka] 【0453】 <Step 3: Synthesis of 3-bromo-3'',5,5',5''-tetra-tert-butyl-1,1':3',1''-terphenyl> 5.0 g (11.1 mmol) of 2-(3',5,5'-tri-tert-butyl[1,1'-biphenyl]-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, 4.8 g (16.7 mmol) of 1,3-dibromo-5-tert-butylbenzene, 4.6 g (33.3 mmol) of potassium carbonate, 56 mL of toluene, 22 mL of ethanol, and 17 mL of tap water were placed in a three-necked flask. After degassing under reduced pressure, the flask was purged with nitrogen, and 50 mg (0.22 mmol) of palladium acetate and 116 mg (0.44 mmol) of triphenylphosphine were added. The mixture was heated at 80°C for approximately 10 hours. After returning to room temperature, the organic and aqueous layers were separated. Magnesium sulfate was added to the solution to remove water and concentrate it. The resulting hexane solution was purified by silica gel column chromatography to obtain 3.0 g of the target product as a white solid in 51.0% yield. Furthermore, the synthesis scheme for 3-bromo-3'',5,5',5''-tetra-tert-butyl-1,1':3',1''-terphenyl in Step 3 is shown in the following formula. 【0454】 [ka] 【0455】 <Step 4: Synthesis of mmtBumTPoFBi-02> In a three-necked flask, 5.8 g (10.9 mmol) of 3-bromo-3'', 5,5',5''-tetra-tert-butyl-1,1':3',1''-terphenyl obtained in step 3, 3.9 g (10.9 mmol) of N-(1,1'-biphenyl-4-yl)-N-phenyl-9,9-dimethyl-9H-fluoren-2-amine, 3.1 g (32.7 mmol) of sodium-tert-butoxide, and 55 mL of toluene were placed. After degassing under reduced pressure, the flask was purged with nitrogen, and 64 mg (0.11 mmol) of bis(dibenzylideneacetone)palladium(0) and 132 mg (0.65 mmol) of tri-tert-butylphosphine were added. The mixture was heated at 80°C for approximately 2 hours. After that, the flask temperature was reduced to approximately 60°C, approximately 1 mL of water was added, the precipitated solid was filtered off, and washed with toluene. The filtrate was concentrated, and the resulting toluene solution was purified by silica gel column chromatography. The obtained solution was concentrated to obtain a concentrated toluene solution. Ethanol was added to this toluene solution, and it was concentrated under reduced pressure to obtain an ethanol suspension. The precipitate was filtered at approximately 20°C, and the resulting solid was dried under reduced pressure at approximately 80°C to obtain 8.1 g of the target white solid in a yield of 91%. The synthesis scheme of mmtBumTPoFBi-02 is shown in the following formula. 【0456】 [ka] 【0457】 Furthermore, nuclear magnetic resonance spectroscopy of the white powder obtained above ( 1 The results of the analysis by 1H-NMR are shown below. From this, it was found that N-(1,1'-biphenyl-2-yl)-N-(3,3'',5',5''-tetra-tert-butyl-1,1':3',1''-terphenyl-5-yl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: mmtBumTPoFBi-02) was synthesized in this synthesis example. 【0458】 1H-NMR.δ(CDCl3):7.56(d,1H,J=7.4Hz),7.50(dd,1H,J=1.7Hz),7.33-7.46(m,11H),7.27-7.29(m,2H),7.22(dd,1H,J=2.3Hz),7 .15(d,1H,J=6.9Hz),6.98-7.07(m,7H),6.93(s,1H),6.84(d,1H,J=6.3Hz),1.38(s,9H),1.37(s,18H),1.31(s,6H),1.20(s,9H). 【0459】 Furthermore, the refractive index of mmtBumTPoFBi-02 was measured using a spectroscopic ellipsometer (M-2000U, manufactured by J.A. Woolam Japan). For the measurement, a film was used in which each layer of material was deposited on a quartz substrate by vacuum deposition, with a thickness of approximately 50 nm. 【0460】 As a result, mmtBumTPoFBi-02 was found to be a material with a low refractive index, with a paraphoton refractive index of 1.69 to 1.70 across the entire blue emission region (455 nm to 465 nm), ranging from 1.50 to 1.75, and a paraphoton refractive index of 1.64 at 633 nm, also ranging from 1.45 to 1.70. 【0461】 ≪Reference synthesis example 4≫ This example describes the synthesis method of N-(4-cyclohexylphenyl)-N-(3,3'',5',5''-tetra-tert-butyl-1,1':3',1''-terphenyl-5-yl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as mmtBumTPchPAF-02), which was used as a low refractive index organic compound in Example 1. The structure of mmtBumTPchPAF-02 is shown below. 【0462】 [ka] 【0463】 <Step 1: Synthesis of 3-bromo-3',5,5'-tri-tert-butylbiphenyl> The synthesis was performed in the same manner as in Step 1 of Reference Synthesis Example 3. 【0464】 <Step 2: Synthesis of 2-(3',5,5'-tri-tert-butyl[1,1'-biphenyl]-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane> The synthesis was performed in the same manner as in step 2 of reference synthesis example 3. 【0465】 <Step 3: Synthesis of 3-bromo-3'',5,5',5''-tetra-tert-butyl-1,1':3',1''-terphenyl> The synthesis was performed in the same manner as in step 3 of Reference Synthesis Example 3. 【0466】 <Step 4: Synthesis of mmtBumTPchPAF-02> In a three-necked flask, 3.0 g (5.6 mmol) of 3-bromo-3'', 5,5',5''-tetra-tert-butyl-1,1':3',1''-terphenyl obtained in step 3, 2.1 g (5.6 mmol) of N-(4-cyclohexylphenyl)-N-(9,9-dimethyl-9H-fluoren-2yl)amine, 1.6 g (16.9 mmol) of sodium-tert-butoxide, and 28 mL of toluene were placed. After degassing under reduced pressure, the flask was purged with nitrogen, and 65 mg (0.11 mmol) of bis(dibenzylideneacetone)palladium(O) (abbreviated as Pd(dba)2) and 139 mg (0.34 mmol) of 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (abbreviated as S-Phos) were added. The mixture was heated at 80°C for approximately 2 hours. Subsequently, the flask temperature was returned to approximately 60°C, approximately 1 mL of water was added, the precipitated solid was filtered off, and washed with toluene. The filtrate was concentrated, and the resulting toluene solution was purified by silica gel column chromatography. The resulting solution was concentrated to obtain a concentrated toluene solution. Ethanol was added to this toluene solution, and it was concentrated under reduced pressure to obtain an ethanol suspension. The precipitate was filtered at approximately 20°C, and the resulting solid was dried under reduced pressure at approximately 80°C to obtain 3.7 g of the target white solid in 80% yield. The synthesis scheme of mmtBumTPchPAF-02 is shown in the following equation. 【0467】 [ka] 【0468】 Furthermore, nuclear magnetic resonance spectroscopy of the white solid obtained from the above ( 1 The results of the analysis by 1H-NMR are shown below. From this, it was found that N-(4-cyclohexylphenyl)-N-(3,3'',5',5''-tetra-tert-butyl-1,1':3',1''-terphenyl-5-yl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: mmtBumTPchPAF-02) was synthesized in this synthesis example. 【0469】 1 H-NMR.δ(CDCl3):7.62(d,1H,J=7.5Hz),7.56(d,1H,J=8.0Hz),7.50(dd,1H,J=1.7Hz),7.4 6-7.47(m,2H),7.43(dd,1H,J=1.7Hz),7.37-7.39(m,3H),7.29-7.32(m,2H),7.23-7.25(m ,2H),7.20(dd,1H,J=1.7Hz),7.09-7.14(m,5H),7.05(dd,1H,J=2.3Hz),2.46(brm,1H),1. 83-1.88(m,4H),1.73-1.75(brm,1H),1.42(s,6H),1.38(s,9H),1.36(s,18H),1.29(s,9H) 【0470】 Next, 3.5 g of the obtained white solid was purified by sublimation using the train sublimation method under conditions of a pressure of 4.0 Pa, an argon flow rate of 15.0 mL / min, and a temperature of 265 °C. After sublimation purification, 3.1 g of a slightly yellowish-white solid was obtained with a recovery rate of 89%. 【0471】 Furthermore, the refractive index of mmtBumTPchPAF-02 was measured using a spectroscopic ellipsometer (M-2000U, manufactured by J.A. Woolam Japan). For the measurement, a film was used in which each layer of material was deposited on a quartz substrate by vacuum deposition, with a thickness of approximately 50 nm. 【0472】 As a result, mmtBumTPchPAF-02 was found to be a material with a low refractive index, with a paraphoton refractive index of 1.67 to 1.68 across the entire blue emission region (455 nm to 465 nm), ranging from 1.50 to 1.75, and a paraphoton refractive index of 1.62 at 633 nm, also ranging from 1.45 to 1.70. [Explanation of Symbols] 【0473】 101 Anode 102 Cathode 103 EL layer 111 Hole injection layer 112 Hole transport layer 113 Emitting layer 114 Electron transport layer 115 Electron injection layer 116 Charge generation layer 117 P type layer 118 Electron relay layer 119 Electron injection buffer layer 400 circuit boards 401 Anode 403 EL layer 404 Cathode 405 sealant 406 Sealant 407 Sealing substrate 412 pads 420 IC chips 601 Drive circuit section (source line drive circuit) 602 pixel section 603 Drive circuit section (gate wire drive circuit) 604 Sealing substrate 605 Sealant 607 Space 608 Wiring 609 FPC (Flexible Printed Circuit) 610 element substrate 611 Switching FET 612 Current-Controlled FET 613 Anode 614 Insulators 616 EL layer 617 Cathode 618 Light-emitting devices 951 circuit board 952 Electrode 953 Insulating layer 954 Partition layer 955 EL layer 956 Electrode 1001 circuit board 1002 Underlying insulating film 1003 Gate Insulator 10:06 Guard Station 1007 🙏 1008 Gate 1020 First interlayer insulating film 1021 Second interlayer insulating film 1022 Electrode 1024W anode 1024R Anode 1024G anode 1024B Anode 1025 Bulkhead 1028 EL layer 1029 Cathode 1031 Sealing substrate 1032 Sealant 1033 Transparent base material 1034R Red colored layer 1034G Green colored layer 1034B Blue colored layer 1035 Black Matrix 1036 Overcoat layer 1037 Third interlayer insulating film 1040 pixel section 1041 Drive circuit section 1042 Peripheral area 2001 cabinet 2002 light source 2100 Robots 2110 Arithmetic equipment 2101 Illuminance Sensor 2102 Microphone 2103 Top camera 2104 Speaker 2105 Display 2106 Lower Camera 2107 Obstacle Sensor 2108 Moving mechanism 3001 Lighting device 5000 cabinets 5001 Display section 5002 Display section 5003 Speaker 5004 LED Lamp 5005 Operation Keys 5006 Connection terminal 5007 Sensor 5008 Microphone 5012 Support part 5013 Earphones 5100 Cleaning Robot 5101 Display 5102 Camera 5103 Brush 5104 Operation Buttons 5150 Mobile Information Terminal 5151 enclosure 5152 Display area 5153 Bent section 5120 Garbage 5200 display area 5201 Display area 5202 Display area 5203 Display area 7101 enclosure 7103 Display section 7105 Stand 7107 Display section 7109 Operation Keys 7110 Remote Control Unit 7201 Main Unit 7202 enclosure 7203 Display section 7204 Keyboard 7205 External connection port 7206 Pointing device 7210 Display section 7401 enclosure 7402 Display section 7403 Operation Buttons 7404 External connection port 7405 Speaker 7406 Microphone 7400 mobile phones 9310 Mobile Information Terminal 9311 Display Panel 9313 Hinge 9315 enclosure

Claims

[Claim 1] Anode and, Cathode and, Between the anode and the cathode, there is a light-emitting layer and a hole transport region, The hole transport region is located between the anode and the light-emitting layer. A light-emitting device comprising an organic compound having an arylamine structure in the hole transport region, wherein the ordinary refractive index of the deposited film for light at a wavelength of 458 nm is 1.50 or more and 1.75 or less, and the birefringence Δn of the deposited film for light at a wavelength of 458 nm is 0 or more and 0.008 or less. [Claim 2] In claim 1, A light-emitting device wherein at least one nitrogen atom of the amine in the arylamine structure of the organic compound is bonded to a group containing a parabiphenyl structure. [Claim 3] In claim 1 or claim 2, A light-emitting device in which the organic compound is an organic compound in which a hydrogen atom is bonded to the meta carbon in one or more aniline structures contained in the arylamine structure. [Claim 4] In any one of claims 1 to 3, A light-emitting device in which the organic compound is an organic compound in which one or more benzene rings in the arylamine structure contained in the arylamine structure each independently have substituents at the para position. [Claim 5] In claim 4, A light-emitting device in which the organic compound is an organic compound in which one of the benzene rings in the multiple aniline structures contained in the arylamine structure has a cyclohexyl group at the para position. [Claim 6] In claim 4, A light-emitting device in which the organic compound is an organic compound in which one of the benzene rings in the multiple aniline structures contained in the arylamine structure has a phenyl group in the ortho position. [Claim 7] In any one of claims 1 to 6, A light-emitting device in which the aforementioned organic compound is an organic compound having a triarylamine structure. [Claim 8] In any one of claims 1 to 7, A light-emitting device in which the organic compound is an organic compound in which a fluorenyl group is bonded to the nitrogen of the amine in the arylamine structure. [Claim 9] In any one of claims 1 to 8, A light-emitting device in which the aforementioned organic compound is a monoamine compound. [Claim 10] In any one of claims 1 to 9, The hole transport region comprises a hole injection layer and a hole transport layer, The hole injection layer is located between the anode and the hole transport layer. A light-emitting device in which the aforementioned organic compound is contained in the hole transport layer. [Claim 11] In any one of claims 1 to 9, The hole transport region comprises a hole injection layer and a hole transport layer, The hole injection layer is located between the anode and the hole transport layer. A light-emitting device in which the organic compound is contained in both the hole injection layer and the hole transport layer. [Claim 12] In claim 11, The hole injection layer contains a substance that exhibits acceptability to the organic compound in the light-emitting device. [Claim 13] In claim 12, A light-emitting device in which the substance exhibiting the aforementioned acceptability is an organic compound. [Claim 14] A light-emitting device according to any one of claims 1 to 13, An electronic device having at least one of a sensor, an operating button, a speaker, and a microphone. [Claim 15] A light-emitting device according to any one of claims 1 to 13, A light-emitting device having at least one of a transistor and a substrate. [Claim 16] A lighting device comprising a light-emitting device according to any one of claims 1 to 13, and a housing.

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