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

Abstract

This provides a novel organometallic complex. [Solution] An organometallic complex represented by general formula (G1) comprises iridium, a first ligand, and a second ligand, wherein the first and second ligands are cyclometalated ligands, the first ligand has a quinoline ring coordinating to iridium, the second ligand has a pyrimidine ring coordinating to iridium, at least one of the first and second ligands has a substituted or unsubstituted aryl group as a substituent, and the first ligand is present in twice the proportion of the second ligand. JPEG2026108694000022.jpg58167

Description

Technical Field

[0001] One aspect of the present invention relates to an organometallic complex. In particular, it relates to an organometallic complex capable of converting energy in the triplet excited state into light emission. It also relates to a light-emitting device, a light-emitting apparatus, an electronic device, and a lighting device using the organometallic complex. Note that one aspect of the present invention is not limited to the above technical field. The technical field of one aspect of the invention disclosed in this specification and the like relates to an article, a method, or a manufacturing method. Or, one aspect of the present invention relates to a process, a machine, a manufacture, or a composition of matter. Therefore, more specifically, as the technical field of one aspect of the present invention disclosed in this specification, in addition to the above, semiconductor devices, display devices, liquid crystal display devices, power storage devices, storage devices, their driving methods, or their manufacturing methods can be cited as an example.

Background Art

[0002] In recent years, research and development of light-emitting elements (organic EL elements) using electroluminescence (EL) using organic compounds have been actively carried out.The basic configuration of these light-emitting elements is one in which an organic compound layer (EL layer) containing a light-emitting substance is sandwiched between a pair of electrodes.By applying a voltage to this element, light emission from the light-emitting substance can be obtained.

[0003] Since organic EL elements are self-emitting, they have advantages such as higher pixel visibility compared to liquid crystal displays and no need for a backlight, and are considered suitable as flat panel display elements. In addition, organic EL elements can obtain planar light emission.This is a characteristic that is difficult to obtain with point light sources typified by incandescent bulbs and LEDs, or line light sources typified by fluorescent lamps, and thus has high utility value for lighting and the like.

[0004] In an organic EL device, electrons are injected from the cathode and holes are injected from the anode into the EL layer, respectively. When they recombine, a light-emitting organic compound is excited to a state where light emission can be obtained. As types of excited states, there are singlet excited states (S * ), and triplet excited states (T * ). Light emission from a singlet excited state is called fluorescence, and light emission from a triplet excited state is called phosphorescence. Also, the statistical generation ratio of these in a light-emitting device is considered to be S * :T * = 1:3.

[0005] Among the above light-emitting substances, a compound capable of converting the energy in a singlet excited state into light emission is called a fluorescent compound (fluorescent material), and a compound capable of converting the energy in a triplet excited state into light emission is called a phosphorescent compound (phosphorescent material).

[0006] Therefore, based on the above generation ratio, the theoretical limit of the internal quantum efficiency (the ratio of photons generated with respect to the injected carriers) in a light-emitting device using each of the above light-emitting substances is 25% when using a fluorescent material and 75% when using a phosphorescent material.

[0007] That is, compared with a light-emitting device using a fluorescent material, a light-emitting device using a phosphorescent material can obtain higher efficiency. Therefore, in recent years, the development of various types of phosphorescent materials has been actively carried out. In particular, due to the high phosphorescence quantum yield, organometallic complexes having iridium or the like as a central metal have attracted attention (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] As reported in Patent Document 1 above, progress is being made in developing phosphorescent materials that exhibit excellent properties, but there is a need for the development of new materials that exhibit even better properties.

[0010] Therefore, one aspect of the present invention provides a novel organometallic complex. Another aspect of the present invention provides a novel organometallic complex that can be used in a light-emitting device. Another aspect of the present invention provides a novel organometallic complex that can be used in the EL layer of a light-emitting device. Another aspect of the present invention provides a novel light-emitting device. Another aspect of the present invention provides a novel light-emitting device, a novel electronic device, or a novel lighting device. The description of these problems does not preclude the existence of other problems. One aspect of the present invention does not necessarily have to solve all of these problems. Other problems will naturally become clear from the description in the specification, drawings, claims, etc., and it is possible to extract other problems from the description in the specification, drawings, claims, etc. [Means for solving the problem]

[0011] One aspect of the present invention is an organometallic complex comprising iridium, a first ligand, and a second ligand, wherein the first ligand and the second ligand are cyclometalated ligands, the first ligand has a quinoline ring coordinating to iridium, the second ligand has a pyrimidine ring coordinating to iridium, at least one of the first ligand and the second ligand has a substituted or unsubstituted aryl group as a substituent, and the first ligand is present in a ratio twice that of the second ligand.

[0012] Another aspect of the present invention is an organometallic complex having a structure represented by the following general formula (G1).

[0013] [ka]

[0014] Note that in the general formula (G1), R 1 ~R16 independently represents any one of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, and a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms.

[0015] Also, one aspect of the present invention is an organometallic complex represented by the following general formula (G2).

[0016] [Chemical formula]

[0017] In the general formula (G2), R 1 ~R 15 , R 17 ~R 21 independently represents any one of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, and a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms.

[0018] An organometallic complex according to one embodiment of the present invention, shown in general formulas (G1) and (G2), has as ligands two phenylquinoline compounds, which mainly contain the highest occupied molecular orbital (HOMO), and one phenylpyrimidine compound, which mainly contains the lowest unoccupied molecular orbital (LUMO). By spatially separating the HOMO and LUMO in this way, holes are injected into the phenylquinoline ligand, which has high resistance to holes, and electrons are injected into the phenylpyrimidine ligand, which has high resistance to electrons, thus obtaining an organometallic complex with high resistance to both holes and electrons. This also means that holes and electrons remain separated even in the excited state, contributing to stabilization in the excited state. Furthermore, because the hole and electron injection properties of the organometallic complex are improved, the balance between hole and electron transport is improved, and the performance of the device, such as luminescence efficiency and lifetime, is improved. A key feature here is that either the first ligand or the second ligand has at least one aryl group. This improves the thermophysical properties and the chemical and electrical stability of the organometallic complex. In particular, it is preferable for the quinoline ring or pyrimidine ring to have an aryl group because it improves the electrochemical stability of the heterocycle. Furthermore, it is especially preferable for the pyrimidine ring to have an aryl group because it further stabilizes the LUMO and facilitates the separation of the HOMO-LUMO. Thus, by using an organometallic complex according to one aspect of the present invention, the lifespan of the light-emitting device can be extended.

[0019] In addition, for each of the organometallic complexes described above, the full width at half maximum of the emission spectrum is preferably 70 nm or more and 120 nm or less, more preferably 80 nm or more and 120 nm or less, and even more preferably 90 nm or more and 120 nm or less.

[0020] By using organometallic complexes with a broad half-width of emission spectra in light-emitting devices, the color rendering of the device's emission can be improved, resulting in emission that is closer to natural light.

[0021] A broad full width at half maximum (FWHM) of the emission spectrum is due to a large structural change in the transition state of the luminescent material. Therefore, a broad FWHM of the emission spectrum of a luminescent material tends to reduce the luminescence efficiency of the light-emitting device. However, the organometallic complexes with the above configurations can suppress the decrease in luminescence efficiency of the light-emitting device, even though they undergo large structural changes in the transition state. Accordingly, by using organometallic complexes with the above configurations in a light-emitting device, it is possible to obtain a light-emitting device with a broad FWHM of the emission spectrum and high luminescence efficiency.

[0022] Furthermore, in the organometallic complexes of each of the above configurations, it is more preferable that the peak wavelength of the emission spectrum is between 590 nm and 620 nm.

[0023] By using such luminescent organometallic complexes in light-emitting devices, it is possible to obtain light-emitting devices that emit warm-colored light that is closer to natural light such as sunset, incandescent light bulbs, and candlelight, without mixing them with other light colors.

[0024] Furthermore, one aspect of the present invention is an organometallic complex represented by the following structural formula (100).

[0025] [ka]

[0026] Furthermore, an organometallic complex according to one aspect of the present invention can emit phosphorescence, that is, it can obtain light emission from a triplet excited state and exhibit light emission. Therefore, applying it to a light-emitting device makes it possible to increase efficiency and is extremely effective. Accordingly, light-emitting devices using organometallic complexes of the above configurations are included in one aspect of the present invention.

[0027] Furthermore, one aspect of the present invention is a light-emitting device having an EL layer between a pair of electrodes, wherein the EL layer has an organometallic complex having the above-described configuration.

[0028] Furthermore, one aspect of the present invention is a light-emitting device having an EL layer between a pair of electrodes, wherein the EL layer has a light-emitting layer, and the light-emitting layer has an organometallic complex having the above-described configuration.

[0029] In addition, for each of the above configurations of light-emitting devices, the full width at half maximum of the electroluminescence spectrum is preferably 70 nm or more and 120 nm or less, more preferably 80 nm or more and 120 nm or less, and even more preferably 90 nm or more and 120 nm or less.

[0030] By creating a light-emitting device with a wide half-width of the electroluminescence spectrum, the color rendering of the emission can be improved, resulting in emission that is closer to natural light.

[0031] In light-emitting devices, a wide full width at half maximum (FWHM) of the electroluminescence spectrum tends to reduce luminous efficiency. However, by using the above-described configurations for the light-emitting device, it is possible to create a light-emitting device with a wide FWHM of the electroluminescence spectrum and high luminous efficiency.

[0032] Furthermore, in the light-emitting devices of each of the above configurations, it is preferable that the peak wavelength of the electroluminescence spectrum is between 590 nm and 620 nm.

[0033] This makes it possible to create a light-emitting device that emits warm-colored light that is closer to natural light such as sunset, incandescent light bulbs, and candlelight.

[0034] Furthermore, one aspect of the present invention is a light-emitting device having the light-emitting devices of the above configurations and at least one of a transistor or a substrate.

[0035] Furthermore, one aspect of the present invention is an electronic device having the above-described light-emitting device and at least one of a microphone, a camera, an operation button, an external connection part, or a speaker.

[0036] Furthermore, one aspect of the present invention is a lighting device having the light-emitting devices and housings described above.

[0037] Furthermore, one aspect of the present invention includes not only light-emitting devices having light-emitting devices but also lighting devices having light-emitting devices. Accordingly, in this specification, a light-emitting device refers to an image display device or a light source (including a lighting device). In addition, modules to which connectors, such as FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) are attached, modules to which a printed circuit board is provided at the end of the TCP, or modules to which an IC (Integrated Circuit) is directly mounted on the light-emitting device using the COG (Chip On Glass) method are all included as light-emitting devices. [Effects of the Invention]

[0038] One aspect of the present invention can provide a novel organometallic complex. Another aspect of the present invention can provide a novel organometallic complex that can be used in a light-emitting device. Another aspect of the present invention can provide a novel organometallic complex that can be used in the EL layer of a light-emitting device. Furthermore, a novel light-emitting device using the new organometallic complex can be provided. Furthermore, a novel light-emitting device, a novel electronic device, or a novel lighting device can be provided. The description of these effects does not preclude the existence of other effects. Furthermore, one aspect of the present invention does not necessarily have to have all of these effects. Furthermore, other effects will naturally become clear from the description in the specification, drawings, claims, etc., and it is possible to extract other effects from the description in the specification, drawings, claims, etc. [Brief explanation of the drawing]

[0039] [Figure 1] Figures 1A through 1C are schematic diagrams of the light-emitting device. [Figure 2] Figures 2A and 2B are conceptual diagrams of an active matrix type light-emitting device. [Figure 3] Figures 3A and 3B are conceptual diagrams of an active matrix type light-emitting device. [Figure 4]Figure 4 is a conceptual diagram of an active matrix type light-emitting device. [Figure 5] Figures 5A and 5B are conceptual diagrams of a passive matrix type light-emitting device. [Figure 6] Figures 6A and 6B illustrate the configuration of a light-emitting device according to an embodiment. [Figure 7] Figures 7A and 7B illustrate the manufacturing method of a light-emitting device according to an embodiment. [Figure 8] Figures 8A to 8C illustrate a method for manufacturing a light-emitting device according to an embodiment. [Figure 9] Figures 9A to 9C illustrate a method for manufacturing a light-emitting device according to an embodiment. [Figure 10] Figures 10A and 10B illustrate the manufacturing method of a light-emitting device according to an embodiment. [Figure 11] Figures 11A and 11B illustrate a light-emitting device according to an embodiment. [Figure 12] Figures 12A and 12B are diagrams representing lighting devices. [Figure 13] Figures 13A to 13D are diagrams representing electronic devices. [Figure 14] Figures 14A, 14B, and 14C are diagrams representing electronic devices. [Figure 15] Figure 15 is a diagram representing a lighting device. [Figure 16] Figure 16 is a diagram representing a lighting device. [Figure 17] Figure 17 is a diagram representing an in-vehicle display device and lighting system. [Figure 18] Figures 18A and 18B are diagrams representing electronic devices. [Figure 19] Figures 19A, 19B, and 19C are diagrams representing electronic devices. [Figure 20] Figure 20 is the 1H NMR chart for [Ir(pqn)2(dppm)]. [Figure 21] Figure 21 shows the absorption and emission spectra of [Ir(pqn)2(dppm)] in a dichloromethane solution. [Figure 22] Figure 22 is a diagram showing the structure of the light-emitting device 1. [Figure 23] Figure 23 shows the luminance-current density characteristics of the light-emitting device 1. [Figure 24] Figure 24 shows the current efficiency-luminance characteristics of the light-emitting device 1. [Figure 25] Figure 25 shows the luminance-voltage characteristics of the light-emitting device 1. [Figure 26] Figure 26 shows the current-voltage characteristics of the light-emitting device 1. [Figure 27] Figure 27 shows the emission spectrum of the light-emitting device 1. [Figure 28] Figure 28 shows the reliability of the light-emitting device 1. [Modes for carrying out the invention]

[0040] The embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the following description, and 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.

[0041] It should be noted that the terms "film" and "layer" can be interchanged depending on the context or situation. For example, the term "conductive layer" can sometimes be changed to "conductive film." Or, for example, the term "insulating film" can sometimes be changed to "insulating layer."

[0042] (Embodiment 1) This embodiment describes an organometallic complex, which is one aspect of the present invention.

[0043] One aspect of the present invention is an organometallic complex comprising iridium, a first ligand, and a second ligand, wherein the first and second ligands are cyclometalated ligands, the first ligand has a quinoline ring coordinating to iridium, the second aromatic ring has a pyrimidine ring coordinating to iridium, at least one of the first and second ligands has a substituted or unsubstituted aryl group as a substituent, and the first ligand is present in twice the proportion of the second ligand.

[0044] Another aspect of the present invention is an organometallic complex having a structure represented by the following general formula (G1).

[0045] [ka]

[0046] Note that in the general formula (G1), R 1 ~R 16 Each of these independently represents one of the following: hydrogen, a substituted or unsubstituted C1-C6 alkyl group, a substituted or unsubstituted C6-C13 aryl group, and a substituted or unsubstituted C3-C12 heteroaryl group.

[0047] Furthermore, it is preferable that only one aryl group exists for each organometallic complex, which is one embodiment of the present invention. That is, in general formula (G1), R 1 ~R 15 Preferably, one of these represents a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, and the other represents one of hydrogen, a halogen group, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms. This leads to improved sublimation properties of the organometallic complex and contributes to extending the lifespan of the light-emitting device.

[0048] Another aspect of the present invention is an organometallic complex having a structure represented by the following general formula (G2).

[0049] [ka]

[0050] Note that in the general formula (G2), R 1 ~R 15 , R 17 ~R 21 Each of these independently represents one of the following: hydrogen, a substituted or unsubstituted C1-C6 alkyl group, a substituted or unsubstituted C6-C13 aryl group, and a substituted or unsubstituted C3-C12 heteroaryl group.

[0051] Furthermore, R in the above general formula (G1) 1 ~R 16 and R in the above general formula (G2) 1 ~R 15 , R 17 ~R 21 Specific examples of C1-C6 alkyl groups in this context include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, sec-pentyl group, tert-pentyl group, neopentyl group, hexyl group, isohexyl group, sec-hexyl group, tert-hexyl group, neohexyl group, 3-methylpentyl group, 2-methylpentyl group, 2-ethylbutyl group, 1,2-dimethylbutyl group, 2,3-dimethylbutyl group, trifluoromethyl group, and the like.

[0052] Furthermore, R in the above general formula (G1) 1 ~R 16 and R in the above general formula (G2) 1 ~R 15 , R 17 ~R 21Specific examples of aryl groups having 6 to 13 carbon atoms include phenyl groups, tolyl groups (o-tolyl, m-tolyl, p-tolyl), naphthyl groups (1-naphthyl, 2-naphthyl), biphenyl groups (biphenyl-2-yl, biphenyl-3-yl, biphenyl-4-yl), xylyl groups, pentarenyl groups, indenyl groups, fluorenyl groups, phenanthryl groups, and indenyl groups. It should be noted that the above substituents may bond to each other to form a ring. An example of this is when the carbon atom at position 9 of a fluorenyl group has two phenyl groups as substituents, and these phenyl groups bond to each other to form a spirofluorene skeleton.

[0053] Furthermore, R in the above general formula (G1) 1 ~R 16 and R in the above general formula (G2) 1 ~R 15 , R 17 ~R 21 Specific examples of heteroaryl groups having 3 to 12 carbon atoms include imidazolyl, pyrazolyl, pyridyl, pyridazyl, triazyl, benzimidazolyl, quinolyl, carbazolyl, dibenzofuranyl, and dibenzothiophenyl groups.

[0054] In organometallic complexes having the structures represented by the above general formulas (G1) and (G2), if any of the substituted or unsubstituted C1-C6 alkyl groups, substituted or unsubstituted C6-C13 aryl groups, and substituted or unsubstituted C3-C12 heteroaryl groups are substituents, examples of substituents include C1-C6 alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, and hexyl groups; C5-C7 cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, 1-norbornyl, and 2-norbornyl groups; and C6-C12 aryl groups such as phenyl and biphenyl groups. Furthermore, the substituents may be bonded together to form a ring. An example of this is, for example, R in the above general formula (G1). 1~R 16 Or R in the above general formula (G2) 1 ~R 15 , R 17 ~R 21 One example is when one of the groups is a fluorenyl group, which is an aryl group having 13 carbon atoms, and the carbon atom at position 9 of the fluorenyl group has two phenyl groups as substituents, and these phenyl groups bond to each other to form a spirofluorene skeleton.

[0055] An organometallic complex according to one embodiment of the present invention, shown in general formulas (G1) and (G2), has as a ligand two phenylquinoline compounds, which mainly contain the highest occupied molecular orbital (HOMO), and one phenylpyrimidine compound, which mainly contains the lowest unoccupied molecular orbital (LUMO). By spatially separating the HOMO and LUMO in this way, holes are injected into the phenylquinoline ligand, which has high resistance to holes, and electrons are injected into the phenylpyrimidine ligand, which has high resistance to electrons, thus obtaining an organometallic complex with high resistance to both holes and electrons. This also means that holes and electrons remain separated even in the excited state, contributing to stabilization in the excited state. Furthermore, because the hole and electron injection properties of the organometallic complex are improved, the balance between hole and electron transport is improved, and the performance of the device, such as luminescence efficiency and lifetime, is improved. A key feature here is that either the first ligand or the second ligand has at least one aryl group. This improves the thermophysical properties and chemical and electrical stability of the organometallic complex. In particular, it is preferable for the quinoline ring or pyrimidine ring to have an aryl group because it improves the electrochemical stability of the heterocycle. Furthermore, it is especially preferable for the pyrimidine ring to have an aryl group because it further stabilizes the LUMO and facilitates the separation of the HOMO-LUMO. Thus, by using an organometallic complex according to one aspect of the present invention, the lifespan of the light-emitting device can be extended.

[0056] Furthermore, in organometallic complexes having the structures represented by the above general formulas (G1) and (G2), the full width at half maximum (FWHM) of the emission spectrum is preferably 70 nm or more, more preferably 80 nm or more, and even more preferably 90 nm or more. By using organometallic complexes having a wide FWHM of 70 nm or more, more preferably 80 nm or more, and even more preferably 90 nm or more in a light-emitting device, the color rendering of the light-emitting device's emission can be improved, and emission closer to natural light can be obtained. In addition, it is preferable that the FWHM of the emission spectrum is 120 nm or less. This makes it possible to obtain emission with suppressed blue light, as will be described later. Therefore, in organometallic complexes having the structures represented by the above general formulas (G1) and (G2), the FWHM of the emission spectrum is preferably 70 nm or more and 120 nm or less, more preferably 80 nm or more and 120 nm or less, and even more preferably 90 nm or more and 120 nm or less.

[0057] A broad full width at half maximum (FWHM) of the emission spectrum is due to a large structural change in the transition state of the light-emitting material. Therefore, a broad FWHM of the emission spectrum of a light-emitting material tends to reduce the luminescence efficiency of the light-emitting device. However, organometallic complexes having the structures represented by the above general formulas (G1) and (G2) can suppress the decrease in luminescence efficiency of the light-emitting device despite large structural changes in the transition state. Accordingly, by using organometallic complexes having the structures represented by the above general formulas (G1) and (G2) in a light-emitting device, it is possible to obtain a light-emitting device with a broad FWHM of the emission spectrum and high luminescence efficiency.

[0058] Furthermore, in organometallic complexes having the structures represented by the above general formulas (G1) and (G2), it is more preferable that the peak wavelength of the emission spectrum is 590 nm or more and 620 nm or less. By using such an organometallic complex in a light-emitting device, it is possible to obtain a light-emitting device that exhibits warm-colored emission closer to natural light such as sunset, incandescent light bulbs, and candlelight, even without mixing it with other emission colors (even if it is emission by the organometallic complex alone). In this case, in order to get closer to natural light, it is preferable that the full width at half maximum of the emission spectrum be wide, specifically that the full width at half maximum is 70 nm or more, more preferably 80 nm or more, and even more preferably 90 nm or more.

[0059] Furthermore, the warm-colored light emitted by sunsets, incandescent light bulbs, and candle flames stimulates the parasympathetic nervous system and induces a relaxing effect. Therefore, by using an organometallic complex according to one aspect of the present invention, which has a peak wavelength of 590 nm to 620 nm and a full width at half maximum of 70 nm or more, more preferably 80 nm or more, and even more preferably 90 nm or more, in a light-emitting device, a light-emitting device that induces a relaxing effect on the user can be created.

[0060] Furthermore, in the organometallic complex, which is one embodiment of the present invention as shown in general formula (G1) and general formula (G2), it is more preferable that the emission contains almost no blue light. Specifically, it is more preferable that in the emission spectrum, the emission intensity of the visible light component below 495 nm is 1 / 100 or less of the emission intensity at the peak wavelength.

[0061] Blue light refers to high-energy blue light (wavelength 360-495nm) within the visible light spectrum. Because blue light is not absorbed by the retina or lens and reaches the retina, it can cause damage to the retina and optic nerve. There is also the problem of disruption of the circadian rhythm due to exposure to blue light at night. The danger of blue light lies in the fact that the human eye has low visual sensitivity to light in this wavelength range. Therefore, even when exposed to strong blue light, people are often unaware of it, and damage tends to accumulate.

[0062] Therefore, by using an organometallic complex according to one aspect of the present invention, which contains almost no blue light in its emission, in a light-emitting device, it is possible to create a light-emitting device that can suppress eye strain in the user and improve the quality of sleep. From this viewpoint, in order to suppress the blue light component, the full width at half maximum of the emission spectrum of the organometallic complex according to one aspect of the present invention is preferably 120 nm or less.

[0063] As described above, by using an organometallic complex according to one aspect of the present invention, a novel light-emitting device can be obtained. This is a light-emitting device for light therapy that exhibits relaxation effects and improves sleep quality. Specifically, one aspect of the present invention is a light-emitting device for phototherapy in which the peak wavelength of the emission spectrum is 590 nm to 620 nm, the full width at half maximum of the emission spectrum is 70 nm to 120 nm, more preferably 80 nm to 120 nm, and even more preferably 90 nm to 120 nm, and the emission intensity of the visible light component below 495 nm is 1 / 100 or less of the emission intensity at the peak wavelength of the emission spectrum. In this case, it is preferable that the light-emitting device for phototherapy exhibits a warm-colored emission color (e.g., orange) that is closer to natural light such as sunset, incandescent light bulbs, and candlelight. Specifically, it is preferable that the CIE chromaticity x of the light-emitting device for phototherapy is 0.58 to 0.63, and the CIE chromaticity y is 0.37 to 0.42.

[0064] Since the organometallic complex according to one aspect of the present invention alone can provide the spectral characteristics necessary for the above-mentioned phototherapy light-emitting device, the organometallic complex according to one aspect of the present invention is suitable for said phototherapy light-emitting device.

[0065] Next, a specific structural formula of an organometallic complex, which is one aspect of the present invention as described above, is shown below. However, the present invention is not limited to these.

[0066] [ka]

[0067] [ka]

[0068] Furthermore, the organometallic complex represented by the above structural formula is a novel substance capable of phosphorescence emission. While geometric isomers and stereoisomers may exist for these substances depending on the type of ligand, all of these isomers are included in the organometallic complex according to one aspect of the present invention.

[0069] Next, an example of a method for synthesizing an organometallic complex represented by the following general formula (G1), which is one aspect of the present invention, will be described.

[0070] [ka]

[0071] ≪Synthesis method for organometallic complexes represented by general formula (G1)≫ As shown in the synthesis scheme (a) below, an organometallic complex, which is one embodiment of the present invention and is represented by the general formula (G1), is obtained by reacting a dinuclear complex (P) having a halogen-bridged structure with a pyrimidine compound represented by the general formula (G0) in an inert gas atmosphere.

[0072] [ka]

[0073] In the above synthesis scheme (a), X represents a halogen atom, and R 1 ~R 16 Each of these independently represents one of the following: hydrogen, a substituted or unsubstituted C1-C6 alkyl group, a substituted or unsubstituted C6-C13 aryl group, and a substituted or unsubstituted C3-C12 heteroaryl group.

[0074] Furthermore, geometric isomers, optical isomers, and other isomers may be obtained by irradiating the organometallic complex (G1) obtained in the above synthesis scheme (a) with light or heat and reacting it; these are also organometallic complexes represented by the general formula (G1). Alternatively, a binuclear complex (P) having a halogen-bridged structure may be reacted with a dechlorinating agent such as silver trifluoromethanesulfonate to precipitate silver chloride, and then the supernatant may be reacted with a pyrimidine compound represented by the general formula (G0) in an inert gas atmosphere.

[0075] Furthermore, in the present invention, in order to obtain an orthometallic complex having a pyrimidine compound as a ligand, the R of the pyrimidine compound 16 It is preferable to introduce substituents, especially R 16 Preferably, one of the following is used: a substituted or unsubstituted C1-C6 alkyl group, a substituted or unsubstituted C6-C13 aryl group, or a substituted or unsubstituted C3-C12 heteroaryl group. This allows R 16 Compared to the case where hydrogen is used, this method suppresses the decomposition of the halogen-bridged binuclear metal complex during the reaction shown in synthesis scheme (a), resulting in a dramatically higher yield.

[0076] The above describes one example of a method for synthesizing organometallic complexes, which is one aspect of the present invention. However, the present invention is not limited thereto, and the complexes may be synthesized by any other method.

[0077] Furthermore, the organometallic complex described above, which is one aspect of the present invention, is capable of phosphorescence and can therefore be used as a light-emitting material and a light-emitting substance for light-emitting devices.

[0078] Furthermore, by using an organometallic complex according to one aspect of the present invention, it is possible to realize a light-emitting device, light-emitting apparatus, electronic device, or lighting apparatus with high luminous efficiency, low driving voltage, and long lifespan.

[0079] In this embodiment, one aspect of the present invention has been described. Furthermore, in other embodiments, another aspect of the present invention will be described. However, the aspects of the present invention are not limited to these. In other words, since various aspects of the invention are described in this embodiment and other embodiments, the aspects of the present invention are not limited to a specific aspect. For example, an example of application to a light-emitting device was shown as one aspect of the present invention, but the aspects of the present invention are not limited to this. Also, depending on the situation, one aspect of the present invention may be applied to something other than a light-emitting device.

[0080] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments.

[0081] (Embodiment 2) This embodiment describes a light-emitting device using an organometallic complex as described in Embodiment 1.

[0082] In one embodiment of the present invention, the full width at half maximum (FWHM) of the electroluminescence spectrum is preferably 70 nm or more, more preferably 80 nm or more, and even more preferably 90 nm or more. This enhances the color rendering of the light emitted by the light-emitting device, making it possible to obtain light emission that is closer to natural light. Furthermore, it is preferable that the FWHM of the emission spectrum is 120 nm or less. This makes it possible to obtain light emission that suppresses blue light, as will be described later. Accordingly, in organometallic complexes having the structures represented by the above general formulas (G1) and (G2), the FWHM of the emission spectrum is preferably 70 nm or more and 120 nm or less, more preferably 80 nm or more and 120 nm or less, and even more preferably 90 nm or more and 120 nm or less.

[0083] In light-emitting devices, a wide full width at half maximum (FWHM) of the electroluminescence spectrum tends to reduce luminescence efficiency. However, by using the organometallic complex described in Embodiment 1, it is possible to create a light-emitting device with high luminescence efficiency while maintaining a wide FWHM of the electroluminescence spectrum.

[0084] Furthermore, in a light-emitting device according to one embodiment of the present invention, it is more preferable that the peak wavelength of the electroluminescence spectrum is between 590 nm and 620 nm. This makes it possible to create a light-emitting device that emits warm-colored light that is closer to natural light such as sunset, incandescent light bulbs, and candlelight.

[0085] Furthermore, it is more preferable that the light emitted by the light-emitting device according to one embodiment of the present invention contains almost no blue light. Specifically, it is more preferable that, in the electroluminescence spectrum of the light-emitting device according to one embodiment of the present invention, the emission intensity of the visible light component below 495 nm is 1 / 100 or less of the emission intensity at the peak wavelength.

[0086] One embodiment of the present invention is a light-emitting device for light therapy that exhibits a relaxing effect and improves sleep quality. Specifically, one embodiment of the present invention is a light-emitting device for phototherapy in which the peak wavelength of the emission spectrum is 590 nm or more and 620 nm or less, the full width at half maximum of the emission spectrum is 70 nm or more and 120 nm or less, more preferably 80 nm or more and 120 nm or less, and even more preferably 90 nm or more and 120 nm or less, and the emission intensity of the visible light component below 495 nm is 1 / 100 or less of the emission intensity at the peak wavelength of the emission spectrum. In this case, it is preferable that the light-emitting device for phototherapy exhibits a warm-colored emission color (e.g., orange) that is closer to natural light such as sunset, incandescent light bulb, and candlelight. Specifically, it is preferable that the CIE chromaticity x of the light-emitting device for phototherapy is 0.58 or more and 0.63 or less, and the CIE chromaticity y is preferable to be 0.37 or more and 0.42 or less.

[0087] Figure 1A 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. The EL layer 103 has the organometallic complex shown in Embodiment 1.

[0088] The EL layer 103 has a light-emitting layer 113, and the light-emitting layer 113 contains a light-emitting material. The organometallic complex described in Embodiment 1 is preferably used as the light-emitting material. The light-emitting layer 113 may also contain other materials.

[0089] In Figure 1A, the EL layer 103 is shown to include a hole injection layer 111, a hole transport layer 112, an electron transport layer 114, and an electron injection layer 115, in addition to the light-emitting layer 113. However, the configuration of the light-emitting device is not limited to these. It is not necessary to form any of these layers, and it may also have layers with other functions.

[0090] Next, a detailed description of the structure and materials of the light-emitting device described above will be given. 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 organometallic complex disclosed in Embodiment 1.

[0091] 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 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.

[0092] 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 layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer, carrier block layer, exciton block layer, and charge generation layer 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, a light-emitting layer 113, an electron transport layer 114, and an electron injection layer 115, as shown in Figure 1A, and another having a hole injection layer 111, a hole transport layer 112, a light-emitting layer 113, an electron transport layer 114, and a charge generation layer 116, as shown in Figure 1B. The materials constituting each layer are specifically described below.

[0093] The hole injection layer 111 is a layer containing an acceptor substance. Both organic and inorganic compounds can be used as the acceptor substance.

[0094] 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 oxides of transition metals such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide.In addition, 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). Accepting substances can extract electrons from adjacent hole transport layers (or hole transport materials) by applying an electric field.

[0095] 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.

[0096] 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.

[0097] 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 Lubazole (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-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviated as CzPA), 1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene, etc. can be used.Examples of aromatic hydrocarbons include 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 2-tert-butyl-9,10-di(1-naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 2-tert-butyl-9,10-bis(4-phenylphenyl)anthracene (abbreviation: t-BuDBA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 9,10-diphenylanthracene (abbreviation: DPAnth), 2-tert-butylanthracene (abbreviation: t-BuAnth), 9,10-bis(4-methyl-1-naphthyl)anthracene (abbreviation: DMNA), 2-tert- Examples 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. They 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).

[0098] 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.

[0099] 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 the second organic compound is a substance having an N,N-bis(4-biphenyl)amino group, as this allows for the creation of light-emitting devices with a good lifetime. Specifically, the second organic compounds mentioned 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 -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] 4-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 :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: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenyl Nylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazole-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazole-9-yl)phenyl]tris(1,1'-biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazole-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyl Triphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi(9H-fluorene)-2-amine (abbreviation: PCBNBSF), N,N-bis([1,1'-biphenyl]-4-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis([1,1'-biphenyl]-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(1,1'-biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi(9H-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) Riphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-phenyl-4'-(9-phenyl-9H-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), 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)-N-[4-(9-phenyl-9H-carbazole-3- [9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF), 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, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,Examples include 9'-spirobio-9H-fluoren-1-amine.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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. Examples of materials having the above hole transport properties include 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), and 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviated as BP). AFLP), 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: PC Aromatic compounds such as BANB, 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]fluoren-2-amine (abbreviated as PCBAF), and N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirobio[9H-fluoren]-2-amine (abbreviated as PCBASF). Compounds having an amine skeleton, 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. 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.

[0104] 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. Additionally, the organometallic complex described in Embodiment 1 can be used for the light-emitting layer 113.

[0105] The luminescent material can be a fluorescent material, a phosphorescent material, a material that exhibits thermally activated delayed fluorescence (TADF), or any other luminescent material.

[0106] Examples of materials that can be used as fluorescent luminescent substances in the light-emitting layer 113 include 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), and 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-butyl)perylene (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: 2DPABPhA), 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-diphenyltetra Sen (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-diphen Nyl-N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluorantene-3,10-diamine (abbreviation: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]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'-(pyran-4-ylidene) Examples include len-1,6-diyl)bis[(6,N-diphenylbenzo[b]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 exhibit high hole-trapping properties and excellent luminescence efficiency and reliability. Other fluorescent materials can also be used.

[0107] In the light-emitting layer 113, when a phosphorescent material is used as the light-emitting substance, possible materials include, for example, tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazole-3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: [Ir(mpptz-dmp)3]), tris(5-methyl-3,4-diphenyl-4H-1, Organometallic iridium complexes having a 4H-triazole skeleton, such as 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]), and tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1 Organometallic iridium complexes having a 1H-triazole skeleton, such as H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(Mptz1-mp)3]), tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Prptz1-Me)3]), and fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl Organometallic iridium complexes with an imidazole skeleton, such as nyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpmi)3]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridineto]iridium(III) (abbreviation: [Ir(dmpimpt-Me)3]), and bis[2-(4',6'-difluorophenyl)pyridinate-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 2Examples include organometallic iridium complexes that use phenylpyridine derivatives having electron-withdrawing groups, such as iridium(III) acetylacetonate (abbreviated as FIr(acac)), as ligands. These compounds exhibit blue phosphorescence and have emission spectral peaks between 440 nm and 520 nm.

[0108] 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 emission spectral peaks between 500 nm and 600 nm. Organometallic iridium complexes with a pyrimidine skeleton are particularly preferred due to their outstanding reliability and luminescence efficiency.

[0109] 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 spectral peaks between 600 nm and 700 nm. Furthermore, organometallic iridium complexes with a pyrazine skeleton produce a red emission with good chromaticity.

[0110] In addition to the phosphorescent compounds described above, other known phosphorescent substances may be selected and used.

[0111] 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.

[0112] [ka]

[0113] 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 (abbreviation: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9'-phenyl-9H,9'H-3,3'-bicarbazol (abbreviation: PCCzTzn), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2-[4-(10H-phenoxazine-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn) 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 PXZ-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.

[0114] [ka]

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] As materials having hole transport properties, organic compounds having an amine skeleton or a π-electron-rich heteroaromatic ring skeleton are preferred. 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 or a carbazole skeleton are preferred because they have good reliability, high hole transportability, and contribute to reducing the driving voltage.

[0121] 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), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (abbreviated as OXD-7), and 9-[4-(5-phenyl-1, Heterocyclic compounds having a polyazole skeleton, such as 3,4-oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), and 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), and 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quino Quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothienyl) Examples include heterocyclic compounds having a diazine skeleton, such as phenyl]pyrimidine (abbreviated as 4,6mDBTP2Pm-II) and 2,8-bis[3-(dibenzothiophen-4-yl)phenyl]-benzo[h]quinazoline (abbreviated as 4,8mDBtP2Bqn), 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 or heterocyclic compounds having a pyridine skeleton are preferred due to their good reliability.In particular, heterocyclic compounds with a diazine (pyrimidine, pyrazine, etc.) skeleton exhibit high electron transport properties and contribute to reducing the driving voltage.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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 phosphoform (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 phosphoform of the fluorescent material with little effect on carrier transport and carrier recombination. Here, the luminescent phosphoform 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.

[0126] 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 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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).

[0132] 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.

[0133] 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.

[0134] Furthermore, the electron transport layer 114 has an electron mobility of 1 × 10⁻¹⁴ at an electric field strength [V / cm] square root of 600. -7 cm 2 / Vs or more 5×10 -5 cm 2It 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, preventing the light-emitting layer from becoming electron-excessive. Furthermore, it is preferable that the electron transport layer 114 contains an electron-transporting material and an alkali metal or alkaline earth metal element, compound, or complex. These configurations are particularly preferable because they result in a good lifetime when the hole injection layer is formed as a composite material and the HOMO level of the hole-transporting material 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 electron-transporting material is -6.0eV or higher. Furthermore, it is preferable that the electron-transporting material 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.

[0135] 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 an electron transport layer containing an alkali metal or alkaline earth metal or a compound thereof, or an electride. Examples of electrides include a substance obtained by adding electrons to a mixed oxide of calcium and aluminum at a high concentration.

[0136] 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.

[0137] Alternatively, a charge generation layer 116 may be provided instead of the electron injection layer 115 (Figure 1B). 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.

[0138] 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.

[0139] 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.

[0140] 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 or cesium carbonate), alkaline earth metal compounds (including oxides, halides, and carbonates), or rare earth metal compounds (including oxides, halides, and carbonates)).

[0141] 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.

[0142] 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 deposited using dry methods such as vacuum deposition or sputtering, inkjet methods, or spin coating methods. Alternatively, the material may be formed using a wet process with a sol-gel method, or it may be formed using a wet process with a paste of a metallic material.

[0143] 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.

[0144] Furthermore, each electrode or layer described above may be formed using different film deposition methods.

[0145] 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.

[0146] Furthermore, the hole transport layer or 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, is preferably made 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.

[0147] 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 1C. This light-emitting device has multiple light-emitting units between the anode and the cathode. Each light-emitting unit has a configuration substantially similar to the EL layer 103 shown in Figure 1A. In other words, the light-emitting device shown in Figure 1C is a light-emitting device having multiple light-emitting units, while the light-emitting device shown in Figure 1A or Figure 1B is a light-emitting device having one light-emitting unit. Note that the organometallic complex described in Embodiment 1 only needs to be included in at least one of the multiple light-emitting units.

[0148] In Figure 1C, 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 1A, respectively, and the same components described in the explanation of Figure 1A 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.

[0149] 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 1C, 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.

[0150] The charge generation layer 513 is preferably formed with the same configuration as the charge generation layer 116 described in Figure 1B. 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.

[0151] 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.

[0152] Figure 1C 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, it is possible to achieve high-brightness light emission while maintaining a low current density, and to realize a device with a long lifespan. Furthermore, it is possible to realize a light-emitting device that can be driven at a low voltage and consumes low power.

[0153] 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.

[0154] Furthermore, each layer or electrode, such as the EL layer 103, the first light-emitting unit 511, the second light-emitting unit 512, and the charge generation layer, can be formed using methods such as vapor deposition (including vacuum deposition), droplet ejection (also known as inkjet printing), coating, or gravure printing. They may also contain low-molecular-weight materials, medium-molecular-weight materials (including oligomers and dendrimers), or polymer materials.

[0155] (Embodiment 3) This embodiment describes a light-emitting device using the light-emitting device described in Embodiment 2.

[0156] In this embodiment, a light-emitting device fabricated using the light-emitting device described in Embodiment 2 will be explained with reference to Figure 2. Figure 2A is a top view showing the light-emitting device, and Figure 2B is a cross-sectional view obtained by cutting Figure 2A along AB and CD. 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.

[0157] 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 609 is shown here, a printed circuit board (PWB) may be attached to this FPC 609. 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.

[0158] Next, the cross-sectional structure will be explained using Figure 2B. 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.

[0159] 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.

[0160] The structure of the transistor used in the pixel or driving circuit is not particularly limited. For example, it may be an inverse staggered transistor or a staggered transistor. It may also be a top-gate or bottom-gate transistor. The semiconductor material used for the transistor 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.

[0161] 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.

[0162] Here, it is preferable to use oxide semiconductors for semiconductor devices such as transistors used in the pixels or 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.

[0163] 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).

[0164] 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.

[0165] By using such materials as semiconductor layers, fluctuations in electrical properties can be suppressed, enabling the realization of highly reliable transistors.

[0166] 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.

[0167] 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.

[0168] 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.

[0169] 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.

[0170] Furthermore, an insulator 614 is formed to cover the end of the first electrode 613. This can be formed by using a positive-type photosensitive acrylic resin film.

[0171] Furthermore, in order to ensure good coverage of the EL layer and the like that will be formed later, a curved surface with curvature is formed at the upper or lower end of the insulator 614. For example, when a positive-type photosensitive acrylic resin is used as the material for the insulator 614, it is preferable to have a curved surface with a radius of curvature (0.2 μm to 3 μm) only at the upper end of the insulator 614. In addition, either a negative-type photosensitive resin or a positive-type photosensitive resin can be used as the insulator 614.

[0172] An EL layer 616 and a second electrode 617 are formed on the first electrode 613, respectively. Here, it is desirable to use a material with a large work function for the first electrode 613 which functions as an anode. For example, in addition to single-layer films such as ITO film, silicon-containing indium tin oxide film, indium oxide film containing 2-20 wt% zinc oxide, titanium nitride film, chromium film, tungsten film, Zn film, and Pt film, a laminate of titanium nitride film and a film mainly composed of aluminum, or a three-layer structure of titanium nitride film, a film mainly composed of aluminum, and titanium nitride film can be used. Furthermore, a laminated structure has low resistance as wiring, good ohmic contact can be obtained, and it can function as an anode.

[0173] Furthermore, the EL layer 616 is formed by various methods such as vapor deposition using a vapor deposition mask, inkjet printing, and spin coating. The EL layer 616 includes the configuration described in Embodiment 2. Other materials constituting the EL layer 616 may be low molecular weight compounds or high molecular weight compounds (including oligomers and dendrimers).

[0174] Furthermore, it is preferable to use a material with a small work function (such as Al, Mg, Li, Ca, or alloys or compounds thereof (MgAg, MgIn, AlLi, etc.)) for the second electrode 617, which is formed on the EL layer 616 and functions as a cathode. When light generated in the EL layer 616 is transmitted through the second electrode 617, it is preferable to use a laminate of a thin metal film and a transparent conductive film (such as ITO, indium oxide containing 2-20 wt% zinc oxide, indium tin oxide containing silicon, zinc oxide (ZnO), etc.) as the second electrode 617.

[0175] The first electrode 613, the EL layer 616, and the second electrode 617 form a light-emitting device. This light-emitting device is the light-emitting device described in Embodiment 2. Although the pixel portion is made up of multiple light-emitting devices, the light-emitting device in this embodiment may contain a mixture of the light-emitting device described in Embodiment 2 and light-emitting devices having other configurations.

[0176] Furthermore, by bonding the sealing substrate 604 to the element substrate 610 with the sealing material 605, 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 filler material, which may be an inert gas (nitrogen, argon, etc.) or a sealing material. A recess is formed in the sealing substrate, and a desiccant is placed therein to suppress deterioration due to the effects of moisture, which is a preferred configuration.

[0177] Furthermore, it is preferable to use epoxy resin or glass frit for the sealing material 605. It is also desirable that these materials are as impermeable to moisture and oxygen as possible. In addition to glass substrates and quartz substrates, plastic substrates made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fluoride), polyester, or acrylic resin can be used as the material for the sealing substrate 604.

[0178] Although not shown in Figure 2, a protective film may be provided on the second electrode. The protective film may be formed 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.

[0179] 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.

[0180] 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.

[0181] 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 or 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.

[0182] For example, by forming a protective film 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 of a touch panel.

[0183] As described above, a light-emitting device can be obtained using the light-emitting device described in Embodiment 2.

[0184] 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.

[0185] Figure 3 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 3A shows the substrate 1001, the underlayer insulating film 1002, the gate insulating film 1003, the gate electrodes 1006, 1007, 1008, the first interlayer insulating film 1020, the second interlayer insulating film 1021, the peripheral part 1042, the pixel part 1040, the drive circuit part 1041, the first electrodes 1024W, 1024R, 1024G, 1024B of the light-emitting device, the partition wall 1025, the EL layer 1028, the second electrode 1029 of the light-emitting device, the sealing substrate 1031, the sealing material 1032, etc.

[0186] In Figure 3A, 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 3A, there is an emissive layer that emits light to the outside without passing through the colored layers, and an emissive layer that emits light to the outside by passing through each colored layer. Light that does not pass through the colored layers is white, and light that passes through the colored layers is red, green, and blue, so an image can be represented with four colored pixels.

[0187] Figure 3B 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.

[0188] 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. A cross-sectional view of the top-emission type light-emitting device is shown in Figure 4. 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 electrode 1022 connecting 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 planarization role. 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.

[0189] 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 4, 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.

[0190] In the top emission structure shown in Figure 4, 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.

[0191] 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.

[0192] 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.

[0193] The light emitted from the light-emitting layer contained in the EL layer is reflected by the reflective electrode and the semi-transparent / semi-reflective electrode, causing resonance.

[0194] This light-emitting device allows for changing the optical distance between the reflective electrode and the semi-transparent / semi-reflective electrode by varying the thickness of the transparent conductive film, the aforementioned composite material, and the carrier transport material. This makes it possible to enhance light of resonant wavelengths and attenuate light of non-resonant wavelengths between the reflective electrode and the semi-transparent / semi-reflective electrode.

[0195] Furthermore, since the light reflected back by the reflective electrode (first reflected light) interferes significantly with the light that directly enters the semi-transparent / semi-reflective electrode from the light-emitting layer (first incident light), 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 greater than or equal to 1, and λ is the wavelength of the light emission to be amplified). By adjusting this optical distance, the phases of the first reflected light and the first incident light can be aligned, and the light emission from the light-emitting layer can be further amplified.

[0196] In the above configuration, the EL layer may have a structure with multiple light-emitting layers or a structure with a single light-emitting layer. For example, it may be applied to a configuration in which multiple EL layers are provided in a single light-emitting device with a charge generation layer in between, and one or more light-emitting layers are formed in each EL layer, in combination with the tandem light-emitting device configuration described above.

[0197] By incorporating a microcavity structure, it becomes possible to enhance the emission intensity in the front direction at specific wavelengths, thereby reducing power consumption. Furthermore, in the case of a light-emitting device that displays images using four sub-pixels of red, yellow, green, and blue, in addition to the brightness enhancement effect of yellow emission, a microcavity structure tailored to the wavelength of each color can be applied to all sub-pixels, resulting in a light-emitting device with excellent characteristics.

[0198] 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.

[0199] 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 5 shows a passive matrix type light-emitting device manufactured by applying the present invention. Figure 5A is a perspective view of the light-emitting device, and Figure 5B is a cross-sectional view of Figure 5A cut along the X and Y lines. In Figure 5, 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 they get closer to 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.

[0200] 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.

[0201] Furthermore, this embodiment can be freely combined with other embodiments.

[0202] (Embodiment 4) This embodiment describes an example of the configuration of a light-emitting device (also called a display panel) and an example of a manufacturing method, which are aspects of the present invention. The EL layer 103 of the light-emitting device included in the light-emitting device (also called a display panel) shown in this embodiment can be made using the material shown in Embodiment 1.

[0203] <Example of configuration of light-emitting device 700 1> The light-emitting device 700 shown in Figure 6A includes light-emitting devices 550B, 550G, 550R, and a partition wall 528. The light-emitting devices 550B, 550G, 550R, and the partition wall 528 are formed on a functional layer 520 provided on a first substrate 510. The functional layer 520 includes gate line drive circuits and source line drive circuits composed of multiple transistors, as well as wiring to electrically connect them. These drive circuits are electrically connected to the light-emitting devices 550B, 550G, and 550R, respectively, and can drive them. Furthermore, the light-emitting device 700 includes an insulating layer 705 on the functional layer 520 and each light-emitting device, and the insulating layer 705 has the function of bonding the functional layer 520 to the second substrate 770.

[0204] Furthermore, the light-emitting devices 550B, 550G, and 550R have the device structure shown in Embodiment 2. In particular, the case in which the EL layer 103 in the structure shown in Figure 1A differs for each light-emitting device is shown.

[0205] The light-emitting device 550B includes an electrode 551B, an electrode 552, an EL layer 103B, and a block layer 107. The specific configuration of each layer is as shown in Embodiment 2. The EL layer 103B has a laminated structure consisting of multiple layers with different functions, including the light-emitting layer. In Figure 6A, only the hole injection / transport layer 104B is shown among the layers included in the EL layer 103B, which includes the light-emitting layer, but the present invention is not limited to this. The hole injection / transport layer 104B refers to a layer having the functions of a hole injection layer and a hole transport layer as shown in Embodiment 2, and may have a laminated structure. In this specification, the hole injection / transport layer can be interpreted in this way in any light-emitting device. The EL layer 103B may also have an electron injection / transport layer. Similarly, the electron injection / transport layer is a layer having the functions of an electron injection layer and an electron transport layer, and may have a laminated structure.

[0206] Furthermore, the block layer 107 is formed to cover the EL layer 103B formed on the electrode 551B. As shown in Figure 6A, the EL layer 103B has sides (or edges). Therefore, the block layer 107 is formed in contact with the sides (or edges) of the EL layer 103B. This makes it possible to suppress the intrusion of oxygen, moisture, or their constituent elements into the interior from the sides of the EL layer 103B. The hole transport material shown in Embodiment 2 can be used for the block layer 107.

[0207] Furthermore, electrode 552 is formed on block layer 107. Electrode 551B and electrode 552 have overlapping regions. Additionally, EL layer 103B is located between electrode 551B and electrode 552. Therefore, a portion of block layer 107 is positioned between electrode 552 and the side (or end) of EL layer 103B. This prevents electrical short circuits between EL layer 103B and electrode 552, more specifically, between the hole injection / transport layer 104B of EL layer 103B and electrode 552.

[0208] The EL layer 103B shown in Figure 6A has the same configuration as the EL layer 103 described in Embodiment 2. Furthermore, the EL layer 103B can emit, for example, blue light.

[0209] The light-emitting device 550G includes an electrode 551G, an electrode 552, an EL layer 103G, and a block layer 107. The specific configuration of each layer is as shown in Embodiment 3. The EL layer 103G has a laminated structure consisting of multiple layers with different functions, including the light-emitting layer. In Figure 6A, only the hole injection / transport layer 104G is shown among the layers included in the EL layer 103G, which includes the light-emitting layer, but the present invention is not limited to this. The hole injection / transport layer 104G represents a layer having the functions of a hole injection layer and a hole transport layer as shown in Embodiment 2, and may have a laminated structure.

[0210] Furthermore, the block layer 107 is formed to cover the EL layer 103G formed on the electrode 551G. As shown in Figure 6A, the EL layer 103G has sides (or edges). Therefore, the block layer 107 is formed in contact with the sides (or edges) of the EL layer 103G. This makes it possible to suppress the intrusion of oxygen, moisture, or their constituent elements into the interior from the sides of the EL layer 103G. The hole transport material shown in Embodiment 2 can be used for the block layer 107.

[0211] Furthermore, electrode 552 is formed on block layer 107. Electrode 551G and electrode 552 have overlapping regions. Additionally, an EL layer 103G is present between electrode 551G and electrode 552. Therefore, a portion of block layer 107 is positioned between electrode 552 and the side surface of EL layer 103G. This prevents electrical short circuits between EL layer 103G and electrode 552, more specifically, between the hole injection / transport layer 104G of EL layer 103G and electrode 552.

[0212] The EL layer 103G shown in Figure 6A has the same configuration as the EL layer described in Embodiment 2. Furthermore, the EL layer 103G can emit, for example, green light.

[0213] The light-emitting device 550R includes an electrode 551R, an electrode 552, an EL layer 103R, and a block layer 107. The specific configuration of each layer is as shown in Embodiment 2. The EL layer 103R has a laminated structure consisting of multiple layers with different functions, including the light-emitting layer. In Figure 6A, only the hole injection / transport layer 104R is shown among the layers included in the EL layer 103R, which includes the light-emitting layer, but the present invention is not limited to this. The hole injection / transport layer 104R refers to a layer having the functions of a hole injection layer and a hole transport layer as shown in Embodiment 2, and may have a laminated structure.

[0214] Furthermore, the block layer 107 is formed covering the EL layer 103R formed on the electrode 551R. As shown in Figure 6A, the EL layer 103R has sides (or edges). Therefore, the block layer 107 is formed in contact with the sides (or edges) of the EL layer 103R. This makes it possible to suppress the intrusion of oxygen, moisture, or their constituent elements into the interior from the sides of the EL layer 103R. The hole transport material shown in Embodiment 2 can be used for the block layer 107.

[0215] Furthermore, electrode 552 is formed on block layer 107. Electrode 551R and electrode 552 have overlapping regions. Additionally, an EL layer 103R is present between electrode 551R and electrode 552. Therefore, a portion of block layer 107 is positioned between electrode 552 and the side surface of EL layer 103R. This prevents electrical short circuits between EL layer 103R and electrode 552, more specifically, between the hole injection / transport layer 104R of EL layer 103R and electrode 552.

[0216] The EL layer 103R shown in Figure 6A has the same configuration as the EL layer 103 described in Embodiment 2. Furthermore, the EL layer 103R can emit, for example, red light.

[0217] A gap 580 is provided between each of the EL layers 103B, 103G, and 103R. In each EL layer, the hole injection layer, particularly the hole transport region located between the anode and the light-emitting layer, often has high conductivity. Therefore, if it is formed as a layer common to adjacent light-emitting devices, it may cause crosstalk. Accordingly, by providing a gap 580 between each EL layer as shown in this example configuration, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0218] In a high-resolution light-emitting device (display panel) with a resolution exceeding 1000 ppi, if electrical conductivity is detected between the EL layer 103B, EL layer 103G, and EL layer 103R, a crosstalk phenomenon occurs, narrowing the color gamut that the light-emitting device can display. By providing a gap 580 in a high-resolution display panel exceeding 1000 ppi, preferably a high-resolution display panel exceeding 2000 ppi, and more preferably an ultra-high-resolution display panel exceeding 5000 ppi, a display panel capable of displaying vivid colors can be provided.

[0219] As shown in Figure 6B, the partition wall 528 has openings 528B, 528G, and 528R. As shown in Figure 6A, opening 528B overlaps with electrode 551B, opening 528G overlaps with electrode 551G, and opening 528R overlaps with electrode 551R.

[0220] Furthermore, since the separation process of these EL layers (EL layer 103B, EL layer 103G, and EL layer 103R) is performed using photolithography to form patterns, a high-definition light-emitting device (display panel) can be manufactured. In addition, the edges (sides) of the EL layers processed by the photolithography pattern formation have a shape that is substantially the same surface (or substantially located on the same plane). At this time, the gap 580 provided between each EL layer is preferably 5 μm or less, and more preferably 1 μm or less.

[0221] In EL layers, the hole injection layer, particularly the hole transport region located between the anode and the light-emitting layer, often has high conductivity. Therefore, if it is formed as a common layer for adjacent light-emitting devices, it can cause crosstalk. Consequently, by separating the EL layer using photolithography, as shown in this example configuration, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0222] In this specification, devices fabricated using a metal mask or an FMM (Fine Metal Mask, a high-resolution metal mask) may be referred to as MM (Metal Mask) structured devices. Furthermore, in this specification, devices fabricated without using a metal mask or an FMM may be referred to as MML (Metal Maskless) structured devices.

[0223] In this specification, a structure in which different light-emitting layers are created or painted for each color of light-emitting device (here, blue (B), green (G), and red (R)) may be referred to as an SBS (Side By Side) structure. Also, in this specification, a light-emitting device capable of emitting white light may be referred to as a white light-emitting device. A white light-emitting device can be combined with a colored layer (for example, a color filter) to become a full-color display light-emitting device.

[0224] Furthermore, light-emitting devices can be broadly classified into single-structure and tandem-structure devices. In a single-structure device, it is preferable that there is one EL layer between a pair of electrodes, and that this EL layer includes one or more light-emitting layers. To obtain white light emission, it is sufficient to select light-emitting layers such that the light emitted from each of the two or more layers is complementary in color. For example, by making the light-emitting color of the first light-emitting layer and the light-emitting color of the second light-emitting layer complementary, a configuration that emits white light as a whole can be obtained. The same applies to light-emitting devices having three or more light-emitting layers.

[0225] A tandem device preferably has two or more light-emitting units (EL layers) between a pair of electrodes, and each light-emitting unit (EL layer) preferably includes one or more light-emitting layers. To obtain white light emission, the light from the light-emitting layers of the multiple light-emitting units (EL layers) should be combined to produce white light emission. The configuration for obtaining white light emission is the same as for a single-structure device. In a tandem device, it is preferable to provide an intermediate layer, such as a charge-generating layer, between the multiple light-emitting units (EL layers).

[0226] Furthermore, when comparing the aforementioned white light-emitting devices (single or tandem structure) with SBS structure light-emitting devices, SBS structure light-emitting devices can consume less power than white light-emitting devices. If you want to keep power consumption low, it is preferable to use SBS structure light-emitting devices. On the other hand, white light-emitting devices are preferable because their manufacturing process is simpler than that of SBS structure light-emitting devices, which can lead to lower manufacturing costs or higher manufacturing yields.

[0227] <Example 1 of a manufacturing method for a light-emitting device> As shown in Figure 7A, electrodes 551B, 551G, and 551R are formed. For example, a conductive film is formed on a functional layer 520 formed on the first substrate 510, and then processed into a predetermined shape using photolithography.

[0228] Conductive films can be formed using methods such as sputtering, chemical vapor deposition (CVD), vacuum deposition, pulsed laser deposition (PLD), and atomic layer deposition (ALD). CVD methods include plasma-enhanced CVD (PECVD) and thermal CVD. One type of thermal CVD is metal-organic CVD (MOCVD).

[0229] In addition to the photolithography method described above, for the processing of the conductive film, the thin film may be processed by a nanoimprint method, a sandblasting method, a lift-off method, or the like. Also, an island-shaped thin film may be directly formed by a film formation method using a shielding mask such as a metal mask.

[0230] Typically, there are two representative photolithography methods. One is a method in which a resist mask is formed on the thin film to be processed, the thin film is processed by etching or the like, and then the resist mask is removed. The other is a method in which a photosensitive thin film is formed and then exposed and developed to process the thin film into a desired shape.

[0231] In the photolithography method, for the light used in exposure, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or light obtained by mixing these can be used. In addition, ultraviolet light, KrF laser light, ArF laser light, or the like can also be used. Also, exposure may be performed by a liquid immersion exposure technique. Further, as the light used in exposure, extreme ultraviolet (EUV) light or X-rays may be used. Instead of the light used in exposure, an electron beam can also be used. It is preferable to use extreme ultraviolet light, X-rays, or an electron beam because extremely fine processing becomes possible. When exposure is performed by scanning a beam such as an electron beam, a photomask is not required.

[0232] For the etching of the thin film using a resist mask, a dry etching method, a wet etching method, a sandblasting method, or the like can be used.

[0233] Next, as shown in FIG. 7B, a partition wall 528 is formed between the electrode 551B, the electrode 551G, and the electrode 551R. For example, an insulating film covering the electrode 551B, the electrode 551G, and the electrode 551R is formed, openings are formed using photolithography, and it can be formed by exposing a part of the electrode 551B, the electrode 551G, and the electrode 551R. Note that examples of the material that can be used for the partition wall 528 include an inorganic material, an organic material, or a composite material of an inorganic material and an organic material. Specifically, an inorganic oxide film, an inorganic nitride film, an inorganic oxynitride film, or the like, or a laminated material in which a plurality selected from these are laminated, more specifically, a silicon oxide film, a film containing acrylic, a film containing polyimide, or the like, or a laminated material in which a plurality selected from these are laminated can be used.

[0234] Next, as shown in FIG. 8A, an EL layer 103B is formed on the electrode 551B, the electrode 551G, the electrode 551R, and the partition wall 528. In this configuration example, only the hole injection / transport layer 104B included in the EL layer 103B is illustrated. For example, using a vacuum evaporation method, an EL layer 103B is formed on the electrode 551B, the electrode 551G, the electrode 551R, and the partition wall 528 so as to cover them.

[0235] Next, as shown in FIG. 8B, the EL layer 103B on the electrode 551B is processed into a predetermined shape. For example, a resist is formed using photolithography, and the EL layer 103G on the electrode 551G and the EL layer 103R on the electrode 551R are removed by etching to be processed into a shape having a side surface (or a side surface is exposed), or a strip-shaped shape extending in a direction intersecting the plane of the paper. Specifically, dry etching is performed using the resist REG formed on the EL layer 103B overlapping the electrode 551B. (See FIG. 8B). Note that the partition wall 528 can be used as an etching stopper. In this embodiment, when forming a pattern of each EL layer by photolithography, a known method may be applied. That is, a known resist material suitable for an organic material may be used, and specifically, an aqueous resist material can be mentioned.

[0236] Next, as shown in Figure 8C, with the resist REG formed, an EL layer 103G (including a hole injection / transport layer 104G) is formed on the resist REG, electrode 551G, electrode 551R, and partition wall 528. For example, the EL layer 103G is formed on the electrode 551G, electrode 551R, and partition wall 528 using a vacuum deposition method, so as to cover them.

[0237] Next, as shown in Figure 9A, the EL layer 103G on electrode 551G is processed into a predetermined shape. For example, a resist is formed on the EL layer 103G on electrode 551G using photolithography, and the EL layer 103G on electrode 551B and the EL layer 103G on electrode 551R are removed by etching to process the material into a shape with sides (or with exposed sides), or a strip shape extending in a direction intersecting the paper plane. Specifically, dry etching is performed using the resist REG formed on the EL layer 103G overlapping electrode 551G. The partition wall 528 can be used as an etching stopper.

[0238] Next, as shown in Figure 9B, with the resist REG formed on electrodes 551B and 551G, an EL layer 103R (including a hole injection / transport layer 104R) is formed on the resist REG, electrode 551R, and partition wall 528. For example, the EL layer 103R is formed on electrode 551R, resist REG, and partition wall 528 using a vacuum deposition method, so as to cover them.

[0239] Next, as shown in Figure 9C, the EL layer 103R on electrode 551R is processed into a predetermined shape. For example, a resist is formed on the EL layer 103R on electrode 551R using photolithography, and the EL layer 103R on electrode 551B and the EL layer 103R on electrode 551G are removed to process the resist into a shape with sides (or exposed sides), or a strip shape extending in a direction intersecting the paper plane. Specifically, dry etching is performed using the resist REG formed on the EL layer 103R overlapping electrode 551R. The partition wall 528 can be used as an etching stopper.

[0240] Next, as shown in Figure 10A, a block layer 107 is formed on the EL layers (103B, 103G, 103R) and the partition wall 528. For example, a vacuum deposition method is used to form the block layer 107 on the EL layers (103B, 103G, 103R) and the partition wall 528 so as to cover them. In this case, the block layer 107 is formed in contact with the side surfaces of each EL layer (103B, 103G, 103R), as shown in Figure 10A. This suppresses the intrusion of oxygen or moisture, or their constituent elements, into the interior from the side surfaces of each EL layer (103B, 103G, 103R). The hole transport material described in Embodiment 2 can be used as the material for the block layer 107.

[0241] Next, as shown in Figure 10B, an electrode 552 is formed on the block layer 107. The electrode 552 is formed, for example, by vacuum deposition. The electrode 552 is formed on the block layer 107. The block layer 107 has a structure in which a part of it is located between the electrode 552 and the side surfaces of each EL layer (103B, 103G, 103R). This prevents electrical short circuits between each EL layer (103B, 103G, 103R) and the electrode 552, or more specifically, between the hole injection / transport layers (104B, 104G, 104R) of each EL layer (103B, 103G, 103R) and the electrode 552.

[0242] Through the above process, the EL layers 103B, 103G, and 103R of the light-emitting devices 550B, 550G, and 550R can be separated.

[0243] Furthermore, since the separation process of these EL layers (EL layer 103B, EL layer 103G, and EL layer 103R) is performed using photolithography to form patterns, a high-definition light-emitting device (display panel) can be manufactured. In addition, the edges (sides) of the EL layers processed by photolithography have a shape that is substantially the same surface (or is located substantially on the same plane).

[0244] In EL layers, the hole injection layer, particularly the hole transport region located between the anode and the light-emitting layer, often has high conductivity. Therefore, if it is formed as a common layer for adjacent light-emitting devices, it can cause crosstalk. Consequently, by separating the EL layer using photolithography, as shown in this example configuration, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0245] <Example 2 of the configuration of the light-emitting device 700> The light-emitting device 700 shown in Figure 11A includes light-emitting devices 550B, 550G, 550R, and a partition wall 528. The light-emitting devices 550B, 550G, 550R, and the partition wall 528 are formed on a functional layer 520 provided on a first substrate 510. The functional layer 520 includes drive circuits such as a gate line drive circuit and a source line drive circuit composed of multiple transistors, as well as wiring to electrically connect them. These drive circuits are electrically connected to the light-emitting devices 550B, 550G, and 550R, respectively, and can drive them.

[0246] Furthermore, the light-emitting devices 550B, 550G, and 550R have the device structure shown in Embodiment 2. In particular, the case in which each light-emitting device has in common an EL layer 103 having the structure shown in Figure 1B, a so-called tandem structure.

[0247] The light-emitting device 550B has an electrode 551B, an electrode 552, EL layers (103P, 103Q), a charge generation layer 106B, and a block layer 107, and has the laminated structure shown in Figure 11A. The specific configuration of each layer is as shown in Embodiment 2. Also, electrodes 551B and 552 overlap. Furthermore, EL layers 103P and 103Q are laminated with the charge generation layer 106B in between, and EL layers 103P, 103Q, and 106B are located between electrodes 551B and 552. Note that EL layers 103P and 103Q have a laminated structure consisting of multiple layers with different functions, including a light-emitting layer, similar to EL layer 103 described in Embodiment 2. Furthermore, EL layer 103P can emit, for example, blue light, and EL layer 103Q can emit, for example, yellow light.

[0248] In Figure 11A, only the hole injection / transport layer 104P is shown among the layers contained in EL layer 103P, and only the hole injection / transport layer 104Q is shown among the layers contained in EL layer 103Q. Therefore, in the following explanation, when it is possible to explain including the layers contained in each EL layer, the EL layer (EL layer 103P, EL layer 103Q) will be used for convenience.

[0249] Furthermore, the block layer 107 is formed to cover the EL layer 103P, EL layer 103Q, and charge generation layer 106B, which are formed on the electrode 551B. As shown in Figure 11A, the EL layer 103P, EL layer 103Q, and charge generation layer 106B have sides (or edges). Therefore, the block layer 107 is formed in contact with the sides (or edges) of each of the EL layer 103P, EL layer 103Q, and charge generation layer 106B. This makes it possible to suppress the intrusion of oxygen or moisture, or their constituent elements, into the interior from the sides of each of the EL layer 103P, EL layer 103Q, and charge generation layer 106B. The hole transport material shown in Embodiment 2 can be used for the block layer 107.

[0250] Furthermore, electrode 552 is formed on block layer 107. Note that electrode 551B and electrode 552 overlap. Also, EL layer 103P, EL layer 103Q, and charge generation layer 106B are located between electrode 551B and electrode 552. Therefore, the structure has such that a part of block layer 107 is located between electrode 552 and the side surface (or end) of EL layer 103P, between electrode 552 and the side surface of EL layer 103Q, and between electrode 552 and the side surface of charge generation layer 106B. This prevents electrical short circuits between the EL layer 103P and the electrode 552, more specifically between the hole injection / transport layer 104P of the EL layer 103P and the electrode 552, between the EL layer 103Q and the electrode 552, more specifically between the hole injection / transport layer 104Q of the EL layer 103Q and the electrode 552, or between the charge generation layer 106B and the electrode 552.

[0251] The light-emitting device 550G has an electrode 551G, an electrode 552, EL layers (103P, 103Q), a charge generation layer 106G, and a block layer 107, and has the stacked structure shown in Figure 11A. The specific configuration of each layer is as shown in Embodiment 2. Also, electrodes 551G and 552 overlap. Furthermore, EL layers 103P and 103Q are stacked with the charge generation layer 106G in between, and EL layers 103P, 103Q, and 106G are located between electrodes 551G and 552.

[0252] Furthermore, the block layer 107 is formed to cover the EL layer 103P, EL layer 103Q, and charge generation layer 106G formed on the electrode 551G. As shown in Figure 11A, the EL layer 103P, EL layer 103Q, and charge generation layer 106G have sides (or edges). Therefore, the block layer 107 is formed in contact with the sides (or edges) of each of the EL layer 103P, EL layer 103Q, and charge generation layer 106G. This makes it possible to suppress the intrusion of oxygen or moisture, or their constituent elements, into the interior from the sides of each of the EL layer 103P, EL layer 103Q, and charge generation layer 106G. The hole transport material shown in Embodiment 2 can be used for the block layer 107.

[0253] Further, the electrode 552 is formed on the block layer 107. The electrode 551G and the electrode 552 overlap. Between the electrode 551G and the electrode 552, there are an EL layer 103P, an EL layer 103Q, and a charge generation layer 106G. Therefore, a part of the block layer 107 has a structure located between the electrode 552 and the side surface (or end portion) of the EL layer 103P, between the electrode 552 and the side surface of the EL layer 103Q, and between the electrode 552 and the side surface of the charge generation layer 106G. Thereby, it is possible to prevent the EL layer 103P and the electrode 552, more specifically, the hole injection / transport layer 104P included in the EL layer 103P and the electrode 552, the EL layer 103Q and the electrode 552, more specifically, the hole injection / transport layer 104Q included in the EL layer 103Q and the electrode 552, or the charge generation layer 106G and the electrode 552 from being electrically short-circuited.

[0254] The light-emitting device 550R includes an electrode 551R, an electrode 552, EL layers (103P, 103Q), a charge generation layer 106R, and a block layer 107, and has a stacked structure shown in FIG. 11A. The specific configuration of each layer is as shown in Embodiment 2. The electrode 551R and the electrode 552 overlap. The EL layer 103P and the EL layer 103Q are stacked with the charge generation layer 106R interposed therebetween, and between the electrode 551R and the electrode 552, there are an EL layer 103P, an EL layer 103Q, and a charge generation layer 106R.

[0255] Further, the block layer 107 is formed to cover the EL layer 103P, the EL layer 103Q, and the charge generation layer 106R formed on the electrode 551R. As shown in FIG. 11A, the EL layer 103P, the EL layer 103Q, and the charge generation layer 106R have side surfaces (or end portions). Therefore, the block layer 107 is formed in contact with the side surfaces (or end portions) of the EL layer 103P, the EL layer 103Q, and the charge generation layer 106R, respectively. Thereby, it is possible to suppress the intrusion of oxygen or moisture from the side surfaces of the EL layer 103P, the EL layer 103Q, and the charge generation layer 106R into the interior, or the intrusion of these constituent elements. For the block layer 107, the hole-transporting material shown in Embodiment 2 can be used.

[0256] Furthermore, electrode 552 is formed on block layer 107. Note that electrode 551R and electrode 552 overlap. Also, (103P, 103Q) are located between electrode 551R and electrode 552. Note that a part of block layer 107 has a structure in which it is located between electrode 552 and the side surface (or end) of EL layer (103P, 103Q), and between electrode 552 and the side surface of charge generation layer 106R. This prevents electrical short circuits between EL layer 103P and electrode 552, more specifically between the hole injection / transport layer 104P of EL layer 103P and electrode 552, EL layer 103Q and electrode 552, more specifically between the hole injection / transport layer 104Q of EL layer 103Q and electrode 552, or between charge generation layer 106R and electrode 552.

[0257] Furthermore, when separating and processing the EL layers (103P, 103Q) and charge generation layer 106R of each light-emitting device, pattern formation is performed using photolithography, resulting in the edges (sides) of the processed EL layers having approximately the same surface (or being located on approximately the same plane).

[0258] Each light-emitting device has an EL layer (103P, 103Q) and a charge generation layer 106R, each with a gap 580 between them and adjacent light-emitting devices. The hole injection layer and charge generation layer 106R included in the hole transport region of the EL layer (103P, 103Q) often have high conductivity, and if they are formed as layers common to adjacent light-emitting devices, they may cause crosstalk. Therefore, by providing a gap 580 as shown in this example configuration, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0259] In a high-resolution light-emitting device (display panel) with a resolution exceeding 1000 ppi, if electrical conductivity is detected between the EL layer 103B, EL layer 103G, and EL layer 103R, a crosstalk phenomenon occurs, narrowing the color gamut that the light-emitting device can display. By providing a gap 580 in a high-resolution display panel exceeding 1000 ppi, preferably a high-resolution display panel exceeding 2000 ppi, and more preferably an ultra-high-resolution display panel exceeding 5000 ppi, a display panel capable of displaying vivid colors can be provided.

[0260] In this configuration example, the light-emitting devices 550B, 550G, and 550R all emit white light. Therefore, the second substrate 770 has a colored layer CFB, a colored layer CFG, and a colored layer CFR. These colored layers may be partially overlapped, as shown in Figure 11A. By partially overlapping them, the overlapped portion can function as a light-shielding film. In this configuration example, for example, the colored layer CFB uses a material that preferentially transmits blue light (B), the colored layer CFG uses a material that preferentially transmits green light (G), and the colored layer CFR uses a material that preferentially transmits red light (R).

[0261] Figure 11B shows the configuration of light-emitting device 550B when light-emitting devices 550B, 550G, and 550R are light-emitting devices that emit white light. EL layers 103P and 103Q are laminated on electrode 551B with a charge generation layer 106B in between. EL layer 103P has a light-emitting layer 113B that emits blue light EL(1), and EL layer 103Q has a light-emitting layer 113G that emits green light EL(2) and a light-emitting layer 113R that emits red light EL(3).

[0262] Alternatively, a color conversion layer can be used instead of the colored layer described above. For example, nanoparticles, quantum dots, etc., can be used as the color conversion layer.

[0263] For example, instead of the colored layer CFG, a color conversion layer that converts blue light to green light can be used. This allows the blue light emitted by the light-emitting device 550G to be converted to green light. Alternatively, instead of the colored layer CFR, a color conversion layer that converts blue light to red light can be used. This allows the blue light emitted by the light-emitting device 550R to be converted to red light.

[0264] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments.

[0265] (Embodiment 5) In this embodiment, an example of using the light-emitting device described in Embodiment 2 as a lighting device will be explained with reference to Figure 12. By using the light-emitting device described in Embodiment 2 as a lighting device, it is possible to create a lighting device that has a high relaxation effect, a lighting device that can suppress eye strain in the user and improve the quality of sleep, or a lighting device for phototherapy. Figure 12B is a top view of the lighting device, and Figure 12A is a cross-sectional view of ef in Figure 12B.

[0266] 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 2. When light is extracted from the first electrode 401 side, the first electrode 401 is formed from a translucent material.

[0267] A pad 412 for supplying voltage to the second electrode 404 is formed on the substrate 400.

[0268] 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 2, or to a configuration combining the first light-emitting unit 511, the second light-emitting unit 512, and the charge generation layer 513. Please refer to the relevant description for details on these configurations.

[0269] A second electrode 404 is formed by covering the EL layer 403. The second electrode 404 corresponds to the second electrode 102 in Embodiment 2. 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.

[0270] 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.

[0271] 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 12B), which allows for the adsorption of moisture and leads to improved reliability.

[0272] 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.

[0273] 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 lighting device with low power consumption.

[0274] (Embodiment 6) 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.

[0275] 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.

[0276] Figure 13A 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 configured by arranging the light-emitting devices described in Embodiment 2 in a matrix.

[0277] 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.

[0278] 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.

[0279] Figure 13B 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 13B may also have the form shown in Figure 13C. The computer in Figure 13C 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.

[0280] Figure 13D 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.

[0281] The mobile terminal shown in Figure 13D can also be configured to allow information input 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.

[0282] 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.

[0283] 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.

[0284] 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.

[0285] 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.

[0286] 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.

[0287] 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.

[0288] Figure 14A is a schematic diagram showing an example of a cleaning robot.

[0289] 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.

[0290] 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.

[0291] 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.

[0292] 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.

[0293] 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 5101 can be viewed on the portable electronic device 5140, such as a smartphone.

[0294] A light-emitting device according to one aspect of the present invention can be used in a display 5101.

[0295] The robot 2100 shown in Figure 14B 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.

[0296] 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.

[0297] 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.

[0298] 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.

[0299] Figure 14C 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.

[0300] 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.

[0301] Figure 15 shows an example in which the light-emitting device described in Embodiment 2 is used in a desk lamp, which is a lighting device. The desk lamp shown in Figure 15 has a housing 2001 and a light source 2002, and the lighting device described in Embodiment 4 may be used as the light source 2002.

[0302] Figure 16 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.

[0303] The light-emitting device described in Embodiment 2 can also be mounted on the windshield or dashboard of an automobile. Figure 17 shows one embodiment in which the light-emitting device described in Embodiment 2 is used on the windshield or dashboard of an automobile. Display areas 5200 to 5203 are display areas provided using the light-emitting device described in Embodiment 2.

[0304] 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 using oxide semiconductors.

[0305] 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.

[0306] Display area 5203 can also provide various information such as navigation information, speed, RPM, mileage, fuel level, gear status, 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.

[0307] Figures 18A and 18B 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 18A shows the portable information terminal 5150 in its unfolded state. Figure 18B 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.

[0308] 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.

[0309] 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.

[0310] Figures 19A to 19C also show a foldable portable information terminal 9310. Figure 19A shows the portable information terminal 9310 in its unfolded state. Figure 19B shows the portable information terminal 9310 in an intermediate state, either unfolded or folded. Figure 19C 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.

[0311] 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.

[0312] Furthermore, the configuration shown in this embodiment can be used by appropriately combining the configurations shown in Embodiments 1 to 5.

[0313] Furthermore, a compound according to one embodiment of the present invention can be used in photoelectric conversion elements such as organic thin-film solar cells (OPVs) and organic photodiodes (OPDs). More specifically, because it has carrier transport properties, it can be used in carrier transport layers and carrier implantation layers. In addition, by using a mixed film with a donor substance, it can be used as a charge generation layer. Furthermore, because it is photoexcitable, it can be used as a power generation layer and an active layer.

[0314] 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. [Examples]

[0315] <<Synthesis Example 1>> In this example, one embodiment of the organometallic complex of the present invention, shown as structural formula (100) in Embodiment 1, is bis[2-(2-quinolinyl-κN)phenyl-κC][2-(6-phenyl-4-pyrimidinyl-κN 3 This document describes the synthesis method of phenyl-κC]iridium(III) (abbreviation: [Ir(pqn)2(dppm)]). The structure of [Ir(pqn)2(dppm)] is shown below.

[0316] [ka]

[0317] <Step 1: Synthesis of 2-phenylquinoline (abbreviation: Hpqn)> 7.8 g (38 mmol) of 2-bromoquinoline, 5.5 g (45 mmol) of phenylboronic acid, 113 mL of 2 M potassium carbonate aqueous solution, and 125 mL of 1,2-dimethoxyethane (DME) were placed in a 300 mL three-necked flask, and the flask was purged with nitrogen. 1.2 g (1.0 mmol) of tetrakis(triphenylphosphine)palladium was added to this mixture, and the mixture was heated under reflux at 90°C for 3.5 hours. Water was added to the resulting reaction solution, and it was extracted with ethyl acetate. The resulting extract was washed with saturated brine, and anhydrous magnesium sulfate was added to the organic layer and dried. The resulting mixture was filtered by gravity to obtain a filtrate. This filtrate was concentrated to obtain a solid. This solid was dissolved in toluene and filtered by suction through a layer of Celite / alumina / Celite in that order. The filtrate was concentrated to obtain a solid. This solid was produced by silica gel column chromatography. Toluene was used as the developing solvent. The resulting fraction was concentrated to obtain 7.3 g of a white solid in 95% yield. The synthesis scheme for Step 1 is shown in equation (a-1) below.

[0318] [ka]

[0319] <Step 2: Synthesis of di-μ-chlorotetrakis[2-(2-quinolinyl-κN)phenyl-κC]diiridium(III) (abbreviation: [Ir(pqn)2Cl]2])> 3 g (15 mmol) of Hpqn obtained by the synthesis method in Step 1 above, 1.97 g (6.6 mmol) of IrCl3·H2O, 81 mL of 2-ethoxyethanol, and 27 mL of water were placed in a three-necked flask and the flask was purged with argon. The reaction was carried out by irradiating this mixture with microwaves at 400 W and 100 °C for 1 hour and heating. After the predetermined time, the obtained mixture was filtered by suction, and the solid was washed with water and ethanol. The obtained filtrate was concentrated and washed with water and then ethanol to obtain a solid. The solids obtained by the two suction filters were combined and washed with toluene to obtain 2.2 g of orange solid in a yield of 53%. The synthesis scheme for Step 2 is shown in formula (a-2) below.

[0320] [ka]

[0321] <Step 3: Bis[2-(2-quinolinyl-κN)phenyl-κC][2-(6-phenyl-4-pyrimidinyl-κN 3 Synthesis of phenyl-κC]iridium(III) (abbreviation: [Ir(pqn)2(dppm)]) 22.2 g (1.73 mmol) of [Ir(pqn)2Cl] obtained in step 2 above, along with 200 mL of dichloromethane, were placed in a three-necked flask. A mixed solution of 0.89 g (3.5 mmol) of silver trifluoromethanesulfonate (abbreviated as AgOTf) and 15 mL of methanol was added dropwise, and the mixture was stirred at room temperature for 16 hours. After the specified time, the resulting mixture was filtered through Celite, and the filtrate was concentrated to obtain 2.32 g of a deep red solid. The obtained solid, along with 1.2 g (5.19 mmol) of 2,6-diphenylpyrimidine (abbreviated as Hdppm) and 130 mL of ethanol, were placed in a three-necked flask and heated under reflux for 25 hours. The resulting mixture was concentrated, 3 mL of ethanol was added, and the mixture was filtered by suction. The obtained solid was purified by silica gel column chromatography. Dichloromethane was used as the developing solvent. Further purification of 0.79 g of the obtained solid was performed by high-performance liquid chromatography. Chloroform was used as the mobile phase solvent. The obtained solid was washed with hexane to obtain 0.680 g of red solid in a yield of 24%. 0.59 g of the obtained red solid was purified twice by sublimation using the train sublimation method. The sublimation purification conditions were a pressure of 1.5–1.7 × 10⁻⁶. -3 The solid was heated at Pa with an argon flow rate of 0 mL / min at 285-295°C. After sublimation purification, the target red solid was obtained in a yield of 24%. The synthesis scheme for step 3 is shown in formula (a-3) below.

[0322] [ka]

[0323] The protons of the red solid obtained in step 3 above ( 1H) was measured by nuclear magnetic resonance (NMR). The obtained values ​​are shown below. 1 The 1H-NMR chart is shown in Figure 20. From this, it can be seen that in this synthesis example, [Ir(pqn)2(dppm)], which is one embodiment of the organometallic complex of the present invention represented by the above-mentioned structural formula (100), was obtained.

[0324] 1 H-NMR.δ(CD2Cl2):6.44(d,1H),6.55(t,2H),6.72-6.77(m,4H),6.83(t,1H),6.94-6.99(m,2H),7.04(t,1H),7.25-7.31(m,2H),7.48-7.49(m ,3H),7.66(d,1H),7.33-7.78(m,3H),7.92(d,1H),7.96(d,1H),8.05- 8.10(m,4H),8.13(d,1H),8.20(d,1H),8.25-8.29(m,2H),8.34(s,1H).

[0325] Next, the ultraviolet-visible absorption spectrum (hereinafter simply referred to as "absorption spectrum") and emission spectrum of a dichloromethane solution of [Ir(pqn)2(dppm)] were measured. A UV-Vis spectrophotometer (V550, JASCO Corporation) was used to measure the absorption spectrum. The dichloromethane solution (0.0123 mmol / L) was placed in a quartz cell and measured at room temperature. The absorption spectrum was obtained by subtracting the absorption spectrum obtained by placing only dichloromethane in a quartz cell from the absorption spectrum obtained by placing the dichloromethane solution (0.0123 mmol / L) in a quartz cell. An absolute PL quantum yield analyzer (C11347-01, Hamamatsu Photonics Ltd.) was used to measure the emission spectrum. In a glove box (Bright Co., Ltd. LABstarM13 (1250 / 780)), a dichloromethane deoxygenated solution (0.0123 mmol / L) was placed in a quartz cell under a nitrogen atmosphere, sealed tightly, and measured at room temperature.

[0326] The measurement results of the absorption and emission spectra are shown in Figure 21. The horizontal axis represents wavelength, and the vertical axis represents absorption intensity and emission intensity.

[0327] As shown in Figure 21, [Ir(pqn)2(dppm)] has an emission peak at 606 nm, and a reddish-orange emission was observed from the dichloromethane solution. The full width at half maximum of the emission spectrum of [Ir(pqn)2(dppm)] was 104 nm. [Examples]

[0328] In this embodiment, as a light-emitting device according to one aspect of the present invention, we will describe the element structure and characteristics of a light-emitting device 1 that uses [Ir(pqn)2(dppm)] as the light-emitting layer, as described in Example 1. The specific configuration of the light-emitting device 1 used in this embodiment is shown in Table 1. The chemical formulas of the materials used in this embodiment are shown below.

[0329] [Table 1]

[0330] [ka]

[0331] <Fabrication of Light-Emitting Device 1> As shown in Figure 22, the light-emitting device 1 in this embodiment has a structure in which a hole injection layer 911, a hole transport layer 912, a light-emitting layer 913, an electron transport layer 914, and an electron injection layer 915 are sequentially stacked on a first electrode 901 formed on a substrate 900, and a second electrode 903 is stacked on the electron injection layer 915.

[0332] First, a first electrode 901 was formed on the substrate 900. The electrode area was 4 mm². 2 The dimensions were set to (2mm x 2mm). A glass substrate was used for substrate 900. The first electrode 901 was formed by sputtering indium tin oxide (ITSO) containing silicon oxide to a thickness of 70 nm.

[0333] Here, as a pretreatment, the surface of the substrate was washed with water, baked at 200°C for 1 hour, and then subjected to UV ozone treatment for 370 seconds. After that, 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 60 minutes in the heating chamber of the vacuum deposition apparatus, the substrate was allowed to cool for about 30 minutes.

[0334] Next, a hole injection layer 911 was formed on the first electrode 901. The hole injection layer 911 was deposited in a vacuum deposition apparatus. -4 After reducing the pressure to Pa, 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviated as DBT3P-II) and molybdenum oxide (abbreviated as MoOx) were co-deposited at a density of 70 nm, with a mass ratio of DBT3P-II:molybdenum oxide = 2:1.

[0335] Next, a hole transport layer 912 was formed on the hole injection layer 911. The hole transport layer 912 was formed by depositing 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviated as BPAFLP) at a 20 nm deposition rate.

[0336] Next, a light-emitting layer 913 was formed on the hole transport layer 912.

[0337] The light-emitting layer 913 was formed by co-depositing 2-[3-(3'-dibenzothiophen-4-yl)biphenyl]dibenzo[f,h]quinoxaline (abbreviated as 2mDBTBPDBq-II), 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), and [Ir(pqn)2(dppm)] at a density of 40 nm such that 2mDBTBPDBq-II:PCBBiF:[Ir(pqn)2(dppm)] = 0.8:0.2:0.1.

[0338] Next, an electron transport layer 914 was formed on the light-emitting layer 913. The electron transport layer 914 was formed by depositing 2mDBTBPDBq-II at a depth of 30 nm, followed by depositing 2,9-di(2-naphthyl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen) at a depth of 15 nm.

[0339] Next, an electron injection layer 915 was formed on the electron transport layer 914. The electron injection layer 915 was formed by depositing lithium fluoride (LiF) to a thickness of 1 nm.

[0340] Next, a second electrode 903 was formed on the electron injection layer 915. The second electrode 903 was formed by vapor deposition of aluminum to a thickness of 200 nm. In this embodiment, the second electrode 903 functions as a cathode.

[0341] Through the above steps, a light-emitting device 1 was formed on a substrate 900, comprising an EL layer sandwiched between a pair of electrodes. The hole injection layer 911, hole transport layer 912, light-emitting layer 913, electron transport layer 914, and electron injection layer 915 described in the above steps are functional layers constituting the EL layer in one embodiment of the present invention. Furthermore, in the deposition steps of the above-described manufacturing method, a deposition method using resistance heating was used for all steps.

[0342] The fabricated light-emitting device 1 was sealed in a glove box under a nitrogen atmosphere to prevent exposure to the air (sealant was applied around the element, UV treatment was performed during sealing, and heat treatment was performed at 80°C for 1 hour).

[0343] <<Operating characteristics of light-emitting device 1>> Next, the operating characteristics of the light-emitting device 1 were measured. The measurements were performed at room temperature (in an atmosphere maintained at 25°C). Figure 23 shows the luminance-current density characteristics of the light-emitting device 1, Figure 24 shows the current efficiency-luminance characteristics, Figure 25 shows the luminance-voltage characteristics, and Figure 26 shows the current-voltage characteristics. Furthermore, the luminance of the light-emitting device 1 at 1000 cd / m² was also measured. 2 The main initial characteristics in the vicinity are shown in Table 2 below.

[0344] [Table 2]

[0345] Additionally, 2.5 mA / cm² is supplied to the light-emitting device 1. 2 Figure 27 shows the emission spectrum when a current is passed through at the specified current density. As shown in Figure 27, the emission spectrum of light-emitting device 1 has a peak at 603 nm, suggesting that the emission of light-emitting device 1 originates from the organometallic complex [Ir(pqn)2(dppm)] used in its EL layer. The full width at half maximum of the emission spectrum of light-emitting device 1 was 100 nm.

[0346] While a wide full width at half maximum (FWHM) of the electroluminescence spectrum is desirable for high color rendering, this wide FWHM is due to a large structural change in the transition state of the luminescent material used, which leads to a decrease in luminescence efficiency. However, it has been shown that a highly efficient luminescent device can be obtained by using an organometallic complex, one aspect of the present invention. The organometallic complex, one aspect of the present invention, is a suitable material for warm-colored luminescent devices with high efficiency and a wide FWHM of the electroluminescence spectrum.

[0347] Next, a reliability test was performed on the light-emitting device 1. The results of the reliability test are shown in Figure 28. In Figure 28, the vertical axis represents the normalized brightness (%) with the initial brightness set to 100%, and the horizontal axis represents the device's operating time (h). The reliability test was a constant current drive test at 2mA.

[0348] As shown in Figure 28, the reliability test results indicate that the light-emitting device 1 using an organometallic complex, which is one embodiment of the present invention, exhibits high reliability. In this embodiment of the organometallic complex, the HOMO and LUMO are spatially separated by their distribution on different ligands, resulting in an organometallic complex with a shallow HOMO and a deep LUMO overall. In other words, in the organometallic complex used as the light-emitting material in the light-emitting device 1, holes are distributed to the ligand with high resistance to holes (the second ligand where the HOMO is easily distributed) and electrons are distributed to the ligand with high resistance to electrons (the first ligand where the LUMO is easily distributed), both during carrier transport and in the excited state. Therefore, it is believed that stability during carrier transport and in the excited state is increased, making it possible to fabricate a long-lived light-emitting device.

[0349] Furthermore, this separation of HOMO and LUMO allows the organometallic complex itself to transport both carriers. In one embodiment of the present invention, the organometallic complex contains two phenylquinoline compounds, which mainly contain HOMOs, and one phenylpyrimidine compound, which mainly contains LUMOs, as ligands. This improves the hole and electron injection properties of the organometallic complex, as well as the balance between hole and electron transport properties, and the light-emitting region does not narrow easily, thus improving the reliability of the device. This is also considered to be one of the reasons why the lifespan of the light-emitting device has been extended by using the organometallic complex in one embodiment of the present invention. [Explanation of symbols]

[0350] 101: First electrode, 102: Second electrode, 103: EL layer, 103B: EL layer, 103G: EL layer, 103R: EL layer, 103P: EL layer, 103Q: EL layer, 104B: Hole injection / transport layer, 104G: Hole injection / transport layer, 104R: Hole injection / transport layer, 104P: Hole injection / transport layer, 104Q: Hole injection / transport layer, 106B: Charge generation layer, 106G: Charge generation layer, 106R: Charge generation layer, 107: Blocking layer, 111: Hole injection layer, 112: Hole transport layer, 113: Light-emitting layer, 113B: Light-emitting layer, 113G: Light-emitting layer, 113R: Light-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: substrate, 401: first electrode, 403: EL layer, 404: second electrode, 405: sealant, 406: sealant, 407: encapsulation substrate, 412: pad, 420: IC chip, 501: anode, 502: cathode, 510: substrate, 511: first light-emitting unit, 512: second light-emitting unit, 513: charge generation layer, 520: functional layer, 528: partition, 528B: opening, 528G: opening, 528R: opening, 550B: light-emitting device 550G: Light-emitting device, 550R: Light-emitting device, 551B: Electrode, 551G: Electrode, 551R: Electrode, 552: Electrode, 580: Gap, 601: Drive circuit section (source line drive circuit), 602: Pixel section, 603: Drive circuit section (gate line drive circuit), 604: Encapsulation substrate, 605: Sealing material, 607: Space, 608: Wiring, 609: FPC (Flexible Printed Circuit), 610: Element substrate, 611: Switching FET, 612: Current control FET, 613: First electrode, 614: Insulator, 616: EL layer, 617: Second electrode, 618: Light-emitting device Vice, 700: Light-emitting device, 705: Insulating layer, 770: Substrate, 900: Substrate, 901: First electrode, 903: Second electrode, 911: Hole injection layer, 912: Hole transport layer, 913: Light-emitting layer, 914: Electron transport layer, 915: Electron injection layer, 951: Substrate, 952: Electrode, 953: Insulating layer, 954: Partition layer, 955: EL layer, 956: Electrode, 1001: Substrate, 1002: Underlying insulating film, 1003: Gate insulating film, 1006: Gate electrode, 1007: Gate electrode, 1008: Gate electrode, 1020: First interlayer insulating film, 1021: Second interlayer insulating film, 1022: Electrode,1024W: First electrode, 1024R: First electrode, 1024G: First electrode, 1024B: First electrode, 1025: Partition wall, 1028: EL layer, 1029: Second electrode, 1031: Encapsulation substrate, 1032: Sealing material, 1033: Transparent substrate, 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: Driving circuit Part, 1042: Peripheral part, 2001: Housing, 2002: Light source, 2100: Robot, 2110: Processing unit, 2101: Illuminance sensor, 2102: Microphone, 2103: Upper camera, 2104: Speaker, 2105: Display, 2106: Lower camera, 2107: Obstacle sensor, 2108: Moving mechanism, 3001: Lighting device, 5000: Housing, 5001: Display unit, 5002: Display unit, 5003: Speaker, 5004: LED lamp, 5006: Connection terminal, 500 7: Sensor, 5008: Microphone, 5012: Support part, 5013: Earphone, 5100: Cleaning robot, 5101: Display, 5102: Camera, 5103: Brush, 5104: Operation button, 5150: Portable information terminal, 5151: Housing, 5152: Display area, 5153: Bending part, 5120: Dust, 5200: Display area, 5201: Display area, 5202: Display area, 5203: Display area, 7101: Housing, 7103: Display unit, 7105: Stand, 71 07: Display unit, 7109: Operation keys, 7110: Remote control unit, 7201: Main unit, 7202: Enclosure, 7203: Display unit, 7204: Keyboard, 7205: External connection port, 7206: Pointing device, 7210: Second display unit, 7401: Enclosure, 7402: Display unit, 7403: Operation buttons, 7404: External connection port, 7405: Speaker, 7406: Microphone, 9310: Portable information terminal, 9311: Display panel, 9313: Hinge, 9315: Enclosure,

Claims

1. A light-emitting layer is provided between a pair of electrodes. The light-emitting layer is a light-emitting device having an organometallic complex represented by general formula (G1). 【Chemistry 1】 (In general formula (G1), R １ ~R １６ Each of these independently represents one of the following: hydrogen, a substituted or unsubstituted C1-C6 alkyl group, a substituted or unsubstituted C6-C13 aryl group, or a substituted or unsubstituted C3-C12 heteroaryl group.

2. A light-emitting layer is provided between a pair of electrodes. The light-emitting layer is a light-emitting device having an organometallic complex represented by general formula (G2). 【Chemistry 2】 (In general formula (G2), R １ ~R １５ , R １７ ~R ２１ Each of these independently represents one of the following: hydrogen, a substituted or unsubstituted C1-C6 alkyl group, a substituted or unsubstituted C6-C13 aryl group, or a substituted or unsubstituted C3-C12 heteroaryl group.

3. In claim 1 or claim 2, A light-emitting device in which the full width at half maximum of the emission spectrum of the organometallic complex is 70 nm or more and 120 nm or less.

4. In any one of claims 1 to 3, A light-emitting device in which the peak wavelength of the emission spectrum of the organometallic complex is between 590 nm and 620 nm.

5. In any one of claims 1 to 4, A light-emitting device wherein, in the emission spectrum of the organometallic complex, the emission intensity of the visible light component below 495 nm is 1 / 100 or less of the emission intensity at the peak wavelength.

6. In any one of claims 1 to 5, A light-emitting device whose field emission spectrum has a full width at half maximum of 70 nm or more and 120 nm or less.

7. In any one of claims 1 to 6, A light-emitting device whose field emission spectrum peak wavelength is between 590 nm and 620 nm.

8. In any one of claims 1 to 7, A light-emitting device in which, in the electroluminescence spectrum, the emission intensity of the visible light component below 495 nm is 1 / 100 or less of the emission intensity at the peak wavelength.

9. In any one of claims 1 to 8, A light-emitting device having a CIE chromaticity x of 0.58 to 0.63 and a CIE chromaticity y of 0.37 to 0.

42.

10. In any one of claims 1 to 9, The light-emitting layer is a light-emitting device having a TADF material.

11. In any one of claims 1 to 9, The light-emitting layer is a light-emitting device having two types of materials in a combination that forms an excitation complex.

12. A light-emitting device according to any one of claims 1 to 11, A transistor and at least one substrate, A light-emitting device having the following features.

13. The light-emitting device according to claim 12, At least one of the following: microphone, camera, control buttons, external connection port, and speaker, A powerful electronic device.

14. A lighting device comprising a light-emitting device according to any one of claims 1 to 11, and a housing.

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