Organometallic complex and light-emitting device

Abstract

To provide a novel organometallic complex.SOLUTION: The present invention provides an organometallic complex represented by General Formula (G1). (In the organometallic complex represented by General Formula (G1), R1, R13, and R14 each independently represent an alkyl group having 1 to 6 carbon atoms and including deuterium, R2 to R12 each independently represent an alkyl group having 1 to 6 carbon atoms and including deuterium, or hydrogen (including deuterium), R15 to R21 each independently represent hydrogen (including deuterium), and n represents 1 or 2).SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] BACKGROUND ART Organic EL devices (organic EL elements), which are represented by light-emitting devices, light-receiving devices, and light-emitting and receiving devices that utilize electroluminescence (EL) using organic compounds, are being put into practical use.

[0003] For example, the basic structure of a light-emitting device is a pair of electrodes sandwiching an organic compound layer (EL layer) containing a light-emitting material. By applying a voltage to this device, carriers are injected, and the recombination energy of the carriers is utilized to emit light from the light-emitting material.

[0004] The basic structure of a light-receiving device is a pair of electrodes sandwiching an organic compound layer (active layer) containing a photoelectric conversion material. This device absorbs light energy and generates carriers, which can then obtain electrons from the photoelectric conversion material.

[0005] For example, a functional panel is known in which pixels provided in a display area include a light-emitting element (light-emitting device) and a photoelectric conversion element (light-receiving device) (Patent Document 1).

[0006] Thus, displays or lighting devices using organic EL devices are suitable for use in a variety of electronic devices, but research and development is ongoing to develop organic EL devices with better efficiency and life span.

[0007] Although the performance of organic EL devices has improved dramatically, they are still insufficient to meet the high demands for efficiency, durability, and other properties. In particular, to solve problems specific to organic EL devices, such as burn-in, it is desirable to minimize the decrease in efficiency due to degradation.

[0008] Degradation is largely dependent on the light-emitting material and the materials around it, so there has been active development of organic compound materials, including organometallic complexes, that have good properties. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] WO2020 / 152556 [Non-patent literature]

[0010] [Non-Patent Document 1] P. Liehm and five others, Applied Physics Letters, 101, 253304 (2012) Summary of the Invention [Problem to be solved by the invention]

[0011] An object of one embodiment of the present invention is to provide an organometallic complex with high planarity. Another object of one embodiment of the present invention is to provide an organometallic complex that is easily oriented parallel to a substrate. Another object of one embodiment of the present invention is to provide an organometallic complex that is easy to synthesize. Another object of one embodiment of the present invention is to provide a novel organometallic complex. Another object of one embodiment of the present invention is to provide a light-emitting device with high emission efficiency. Another object of one embodiment of the present invention is to provide a novel light-emitting device. Another object of one embodiment of the present invention is to provide a light-emitting device, electronic device, or lighting device with low power consumption.

[0012] Note that the description of these problems does not preclude the existence of other problems. Note that one embodiment of the present invention does not necessarily solve all of these problems. Note that problems other than these will become apparent from the description of the specification, drawings, claims, etc., and it is possible to extract other problems from the description of the specification, drawings, claims, etc. [Means for solving the problem]

[0013] One embodiment of the present invention is an organometallic complex represented by General Formula (G1).

[0014] [ka]

[0015] In the organometallic complex represented by general formula (G1), R 1 , R 13 and R 14 each independently represents a deuterium-containing alkyl group having 1 to 6 carbon atoms; R 2 ~R 12 each independently represents a deuterium-containing alkyl group having 1 to 6 carbon atoms or hydrogen (including deuterium), and R 15 ~R 21 each independently represents hydrogen (including deuterium), and n represents 1 or 2.

[0016] Another embodiment of the present invention is an organometallic complex represented by General Formula (G2).

[0017] [ka]

[0018] In the organometallic complex represented by general formula (G2), R 2 ~R 12 each independently represents a deuterium-containing alkyl group having 1 to 6 carbon atoms or hydrogen (including deuterium), and R 15 ~R 21 each independently represents hydrogen (including deuterium), and n represents 1 or 2.

[0019] In the organometallic complexes having the above structures, n is more preferably 2.

[0020] In the organometallic complexes having the above structures, when the transition dipole moment relating to light emission is defined as vector B, it is more preferable that vector B is 0.5 debye or more.

[0021] An organometallic complex having each of the above structures is provided, in which a vector A is defined connecting the two atoms that are farthest apart in the lowest excited triplet state of the organometallic complex, a plane that includes vector A and that, when the group of atoms that constitute the organometallic complex is projected perpendicularly onto the plane, encloses the projected group of atoms of the organometallic complex and has the largest area, a plane B is defined that is perpendicular to plane A and includes vector A, a transition dipole moment related to the emission of the organometallic complex is defined as vector B, and the angle between vector B' obtained by projecting vector B onto plane B and vector A is 25° or less (however, the direction of vector A is determined so that the angle between vector A and vector B is 90° or less).

[0022] Another embodiment of the present invention is an organometallic complex represented by structural formula (100) or structural formula (101).

[0023] [ka]

[0024] Another embodiment of the present invention is a light-emitting device using any of the organometallic complexes having any of the above structures.

[0025] Another embodiment of the present invention is a light-emitting device including an organometallic complex as a light-emitting material in an light-emitting layer, wherein the organometallic complex has a first ligand and a second ligand, the first ligand having a benzene ring and a pyridine ring, the second ligand having a benzofuro[2,3-b]pyridine ring, and the molecular orientation parameter a of light emitted from the light-emitting device being 0.28 or less.

[0026] Another embodiment of the present invention is a light-emitting device including an organometallic complex having any of the above structures as a light-emitting material in an emission layer, wherein the molecular orientation parameter a of light emitted from the light-emitting device is 0.28 or less. [Effects of the Invention]

[0027] According to one embodiment of the present invention, an organometallic complex with high planarity can be provided. Alternatively, according to one embodiment of the present invention, an organometallic complex that is easily oriented parallel to a substrate can be provided. Alternatively, according to one embodiment of the present invention, an organometallic complex that is easy to synthesize can be provided. Alternatively, according to one embodiment of the present invention, a novel organometallic complex can be provided. Alternatively, according to one embodiment of the present invention, a light-emitting device with high emission efficiency can be provided. Alternatively, according to one embodiment of the present invention, a novel light-emitting device can be provided. Alternatively, according to one embodiment of the present invention, a light-emitting device, electronic device, or lighting device with low power consumption can be provided.

[0028] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. Note that effects other than these will become apparent from the description in the specification, drawings, claims, etc., and it is possible to extract other effects from the description in the specification, drawings, claims, etc. [Brief explanation of the drawings]

[0029] [Figure 1] 1(A) and 1(B) are diagrams illustrating the configuration of a light-emitting device according to an embodiment. [Figure 2] 2(A) to 2(D) are schematic diagrams illustrating the orientation state of molecules. [Figure 3] FIG. 3 is a diagram showing the relationship between the observation direction of the detector in measuring the spatial distribution of the emission intensity and each vector component of the transition dipole moment on the substrate. [Figure 4] 4A to 4F are diagrams illustrating the configuration of a light-emitting device according to an embodiment. [Figure 5] 5(A) and 5(B) are a top view and a cross-sectional view of the light-emitting device. [Figure 6] 6(A) to 6(D) are diagrams showing a light-emitting device. [Figure 7] 7A to 7E are cross-sectional views showing an example of a method for manufacturing a light-emitting device. [Figure 8] 8A and 8B are cross-sectional views showing an example of a method for manufacturing a light-emitting device. [Figure 9] 9A to 9D are cross-sectional views showing an example of a method for manufacturing a light-emitting device. [Figure 10] 10A to 10C are cross-sectional views showing an example of a method for manufacturing a light-emitting device. [Figure 11] 11A to 11C are cross-sectional views showing an example of a method for manufacturing a light-emitting device. [Figure 12] 12A to 12C are cross-sectional views showing an example of a method for manufacturing a light-emitting device. [Figure 13] 13A to 13G are top views showing examples of pixel configurations. [Figure 14] 14A to 14I are top views showing examples of pixel configurations. [Figure 15] 15(A) and 15(B) are perspective views showing configuration examples of a display module. [Figure 16] 16(A) and 16(B) are cross-sectional views showing examples of the configuration of a light-emitting device. [Figure 17] FIG. 17 is a perspective view showing an example of the configuration of a light emitting device. [Figure 18] Fig. 18A is a cross-sectional view showing a structural example of a light-emitting device, Fig. 18B and Fig. 18C are cross-sectional views showing structural examples of a transistor. [Figure 19] FIG. 19 is a cross-sectional view showing an example of the configuration of a light emitting device. [Figure 20] 20A to 20C are cross-sectional views and top views showing structural examples of a light-emitting device. [Figure 21] 21A to 21D are cross-sectional views showing examples of the configuration of a light-emitting device. [Figure 22] 22A to 22C are cross-sectional views and top views showing structural examples of a light-emitting device. [Figure 23] 23A to 23D are diagrams showing examples of electronic devices. [Figure 24] 24(A) to 24(F) are diagrams showing examples of electronic devices. [Figure 25] 25(A) to 25(G) are diagrams showing examples of electronic devices. [Figure 26] Figure 26 is the 1H-NMR spectrum of Ir(5mppy-d3)2(mbfpy5m4ppy-d6) (structural formula (100)). [Figure 27] FIG. 27 shows the absorption spectrum and emission spectrum of Ir(5mppy-d3)2(mbfpy5m4ppy-d6) (structural formula (100)) in dichloromethane solution. [Figure 28]Figure 28 is the 1H-NMR spectrum of Ir(dmppy-d6)2(mbfpy5m4ppy-d6) (structural formula (101)). [Figure 29] FIG. 29 shows the absorption spectrum and emission spectrum of Ir(dmppy-d6)2(mbfpy5m4ppy-d6) (structural formula (101)) in dichloromethane solution. [Figure 30] FIG. 30(A) is a schematic diagram of the device structure of a light-emitting device, and FIG. 30(B) is a schematic diagram of the device structure of a light-emitting device for orientation measurement. [Figure 31] FIG. 31 is a graph showing the luminance-current density characteristics of the light-emitting device 1 and the comparative light-emitting device 2. As shown in FIG. [Figure 32] FIG. 32 is a graph showing the luminance-voltage characteristics of the light-emitting device 1 and the comparative light-emitting device 2. As shown in FIG. [Figure 33] FIG. 33 is a graph showing the current efficiency-current density characteristics of the light-emitting device 1 and the comparative light-emitting device 2. As shown in FIG. [Figure 34] FIG. 34 is a graph showing the current-voltage characteristics of the light-emitting device 1 and the comparative light-emitting device 2. As shown in FIG. [Figure 35] FIG. 35 is a graph showing the external quantum efficiency-current density characteristics of the light-emitting device 1 and the comparative light-emitting device 2. As shown in FIG. [Figure 36] FIG. 36 shows the electroluminescence spectra of Light-Emitting Device 1 and Comparative Light-Emitting Device 2. As shown in FIG. [Figure 37] FIG. 37 is a graph showing the change in luminance with respect to the driving time when a current is applied to the light-emitting device 1 and the comparative light-emitting device 2 and the devices are driven at a constant current. [Figure 38] FIG. 38 is a graph showing the luminance-current density characteristics of the light-emitting device 3 and the comparative light-emitting device 4. As shown in FIG. [Figure 39] FIG. 39 is a graph showing the luminance-voltage characteristics of the light-emitting device 3 and the comparative light-emitting device 4. As shown in FIG. [Figure 40] FIG. 40 is a graph showing the current efficiency-current density characteristics of the light-emitting device 3 and the comparative light-emitting device 4. As shown in FIG. [Figure 41]FIG. 41 is a graph showing the current-voltage characteristics of the light-emitting device 3 and the comparative light-emitting device 4. As shown in FIG. [Figure 42] FIG. 42 is a graph showing the external quantum efficiency-current density characteristics of the light-emitting device 3 and the comparative light-emitting device 4. As shown in FIG. [Figure 43] FIG. 43 shows the electroluminescence spectra of Light-Emitting Device 3 and Comparative Light-Emitting Device 4. As shown in FIG. [Figure 44] FIG. 44 is a graph showing the change in luminance with respect to the driving time when a current is applied to the light-emitting device 3 and the comparative light-emitting device 4 and the devices are driven at a constant current. [Figure 45] FIG. 45 is a diagram showing the luminance-current density characteristics of the light-emitting device 5a and the light-emitting device 5b. [Figure 46] FIG. 46 is a diagram showing the luminance-voltage characteristics of the light-emitting device 5a and the light-emitting device 5b. [Figure 47] FIG. 47 is a diagram showing the current efficiency-current density characteristics of the light-emitting device 5a and the light-emitting device 5b. [Figure 48] FIG. 48 is a diagram showing the current-voltage characteristics of the light-emitting device 5a and the light-emitting device 5b. [Figure 49] FIG. 49 is a graph showing the external quantum efficiency-current density characteristics of the light-emitting device 5a and the light-emitting device 5b. [Figure 50] FIG. 50 shows the electroluminescence spectra of the light-emitting device 5a and the light-emitting device 5b. [Figure 51] FIG. 51 is a diagram showing the luminance-current density characteristics of the light-emitting device 6a and the light-emitting device 6b. [Figure 52] FIG. 52 is a diagram showing the luminance-voltage characteristics of the light-emitting device 6a and the light-emitting device 6b. [Figure 53] FIG. 53 is a diagram showing the current efficiency-current density characteristics of the light-emitting device 6a and the light-emitting device 6b. [Figure 54] FIG. 54 is a diagram showing the current-voltage characteristics of the light-emitting device 6a and the light-emitting device 6b. [Figure 55]FIG. 55 is a graph showing the external quantum efficiency-current density characteristics of the light-emitting device 6a and the light-emitting device 6b. [Figure 56] FIG. 56 is a diagram showing the electroluminescence spectra of the light-emitting device 6a and the light-emitting device 6b. [Figure 57] FIG. 57 is a graph showing the luminance-current density characteristics of the comparative light-emitting device 7a and the comparative light-emitting device 7b. [Figure 58] FIG. 58 is a diagram showing the luminance-voltage characteristics of the comparative light-emitting device 7a and the comparative light-emitting device 7b. [Figure 59] FIG. 59 is a graph showing the current efficiency-current density characteristics of the comparative light-emitting device 7a and the comparative light-emitting device 7b. [Figure 60] FIG. 60 is a diagram showing the current-voltage characteristics of the comparative light-emitting device 7a and the comparative light-emitting device 7b. [Figure 61] FIG. 61 is a graph showing the external quantum efficiency-current density characteristics of the comparative light-emitting device 7a and the comparative light-emitting device 7b. [Figure 62] FIG. 62 shows the electroluminescence spectra of the comparative light-emitting device 7a and the comparative light-emitting device 7b. [Figure 63] FIG. 63 is a diagram showing a method for measuring the molecular orientation parameter a. [Figure 64] FIG. 64 is a graph showing the area intensity at an angle (θ) of the light-emitting device 5a versus the angle (θ) of the detector on the substrate. [Figure 65] FIG. 65 is a graph showing the area intensity at an angle (θ) of the light-emitting device 6a versus the angle (θ) of the detector on the substrate. [Figure 66] FIG. 66 is a graph showing the area intensity at an angle (θ) of the comparative light-emitting device 7a and the angle (θ) of the detector on the substrate. [Figure 67] FIG. 67 is a diagram showing the angles formed with each vector in Ir(5mppy-d3)2(mbfpy5m4ppy-d6) (structural formula (100)). DETAILED DESCRIPTION OF THE INVENTION

[0030] (Embodiment 1) In this embodiment, an organometallic complex which is one embodiment of the present invention and a light-emitting device using the organometallic complex will be described.

[0031] [Example of light-emitting device configuration] First, a structure of a light-emitting device of one embodiment of the present invention will be described with reference to FIGS.

[0032] 1A is a schematic cross-sectional view of a light-emitting device 10 of one embodiment of the present invention. The light-emitting device 10 is provided over a substrate 90 and includes a pair of electrodes (a first electrode 101 and a second electrode 102) and an organic compound layer 103 provided between the pair of electrodes. The organic compound layer 103 includes at least a light-emitting layer 113.

[0033] The organic compound layer 103 shown in FIG. 1A includes functional layers such as 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. The structure of the organic compound layer 103 is not limited to that shown in FIG. 1A and may include at least one selected from the hole-injection layer 111, the hole-transport layer 112, the electron-transport layer 114, and the electron-injection layer 115 in addition to the light-emitting layer 113. Alternatively, the organic compound layer 103 may include a functional layer having a function of reducing a hole or electron injection barrier, improving hole or electron transportability, inhibiting hole or electron transportability, or suppressing quenching caused by an electrode in addition to the light-emitting layer 113. Each functional layer may be a single layer or a stack of multiple layers.

[0034] In the present embodiment, the first electrode 101 of the pair of electrodes is described as an anode and the second electrode 102 as a cathode, but the configuration of the light-emitting device 10 is not limited to this. That is, the first electrode 101 may be the cathode and the second electrode 102 may be the anode, and the layers between the electrodes may be stacked in the reverse order. That is, the stacking order may be, from the anode side, the hole injection layer 111, the hole transport layer 112, the light-emitting layer 113, the electron transport layer 114, and the electron injection layer 115.

[0035] Fig. 1(B) is a cross-sectional view showing an example of the light-emitting layer 113 shown in Fig. 1(A). The light-emitting layer 113 shown in Fig. 1(B) includes a host material 118 (organic compounds 118_1 and 118_2) and a light-emitting material 119.

[0036] A light-emitting organometallic complex may be used as the light-emitting material 119, and a substance that can emit phosphorescence (hereinafter also referred to as a phosphorescent compound) is preferably used as the light-emitting material 119. In the following description, a structure in which an organometallic complex is used as the light-emitting material 119 will be described.

[0037] The light extraction efficiency (χ) is a factor that significantly affects the external quantum efficiency of a light-emitting device. The light extraction efficiency (χ) is related to the structure and layer stack of the light-emitting device, but it is generally said to be 20% to 30% for organic EL devices on a glass substrate. However, this assumes that the light emitted from the light-emitting layer is isotropic; if the light emitted from the light-emitting layer is anisotropic, this value will change. Here, the light emitted from the light-emitting material 119 occurs in a direction perpendicular to the transition dipole moment associated with the light emission (see Figure 2(A)). Therefore, by using a light-emitting material whose transition dipole moment associated with the light emission tends to be oriented parallel to the substrate, anisotropy can be generated in the light emitted from the light-emitting layer, thereby improving the light extraction efficiency (χ) of the light-emitting device.

[0038] Therefore, the inventors developed a highly planar light-emitting material 119 to obtain a light-emitting material in which the transition dipole moment involved in light emission in the light-emitting layer is likely to be oriented parallel to the substrate. When the planarity of the light-emitting material 119 is low, the transition dipole moment involved in light emission of the light-emitting material 119 is less likely to be aligned in the light-emitting layer, as shown in FIG. 2(B), and the light emitted from the light-emitting layer is likely to be isotropic. On the other hand, when the planarity of the light-emitting material 119 is high, the transition dipole moment involved in light emission in the light-emitting layer is more likely to be aligned in the light-emitting layer, as shown in FIG. 2(C), and anisotropy can be generated in the light emitted from the light-emitting layer. Furthermore, when the transition dipole moment involved in light emission of the light-emitting material 119 is oriented parallel to the substrate, as shown in FIG. 2(D), the light emission perpendicular to the substrate increases, thereby improving the light extraction efficiency (χ) of the light-emitting device 10.

[0039] [Molecular design] In the present invention, an organometallic complex having iridium (Ir) as a central metal is used as the light-emitting material 119. The organometallic complex of one embodiment of the present invention includes iridium as a central metal, a first ligand, and a second ligand. The first ligand and the second ligand are each cyclometallated ligands. The first ligand includes a benzene ring and a pyridine ring that are coordinated to the iridium. The second ligand includes a benzofuro[2,3-b]pyridine ring and a pyridine ring that are coordinated to the iridium. In the organometallic complex of one embodiment of the present invention, either the first ligand or the second ligand is present in a ratio twice that of the other of the first ligand and the second ligand.

[0040] In the organometallic complex of one embodiment of the present invention, the carbon atom at position 1 of the benzene ring of the first ligand is coordinated to the central metal, and the carbon atom at position 2 is bonded to the carbon atom at position 2 of the pyridine ring. More preferably, the nitrogen atom at position 1 of the pyridine ring is coordinated to the central metal, and an alkyl group having a deuterium atom is bonded to the carbon atom at position 5 of the pyridine ring.

[0041] In addition, in the benzofuro[2,3-b]pyridine ring of the second ligand of the organometallic complex of one embodiment of the present invention, it is more preferable that the carbon at position 2 has an alkyl group having a deuterium, the carbon at position 7 is coordinated to the central metal, and the carbon at position 8 is bonded to the carbon at position 2 of the pyridine ring.It is more preferable that the nitrogen at position 1 is coordinated to the central metal, the carbon at position 4 is bonded to a phenyl group, and the carbon at position 5 is bonded to an alkyl group having a deuterium.

[0042] In the organometallic complex of one embodiment of the present invention, as described above, a phenyl group is bonded to the carbon atom at the 4-position of the pyridine ring of the second ligand, and the second ligand is elongated, thereby improving the planarity of the metal complex. Therefore, by using such an organometallic complex as the light-emitting material 119, the transition dipole moment involved in the light emission of the light-emitting material 119 is easily oriented, which can cause anisotropy in the light emission from the light-emitting layer.

[0043] Furthermore, when the organometallic complex of one embodiment of the present invention contains twice as many first ligands as the second ligands, the planarity of the organometallic complex is improved, and thus, when the organometallic complex is used as the light-emitting material 119, the vector connecting the two most distant atoms of the light-emitting material 119 is likely to be oriented parallel to the substrate in the light-emitting layer 113. The transition dipole moment involved in light emission of the organometallic complex is likely to be parallel to the vector. Therefore, when such an organometallic complex is used as the light-emitting material 119, the transition dipole moment of the light-emitting material 119 is likely to be oriented parallel to the substrate, and the light extraction efficiency (χ) of the light-emitting device can be improved.

[0044] On the other hand, in the organometallic complex of one embodiment of the present invention, when the ratio of the second ligands to the first ligands is twice as large as that of the first ligands, the number of second ligands involved in light emission increases, and the load of each second ligand decreases, thereby improving stability. Use of such an organometallic complex as the light-emitting material 119 can improve the reliability of the light-emitting device 10.

[0045] As described above, in the organometallic complex of one embodiment of the present invention, a deuterium-containing alkyl group is bonded to the 5-position carbon of the pyridine ring of the first ligand, the 2-position carbon of the benzofuro[2,3-b]pyridine ring of the second ligand, and the 5-position carbon of the pyridine ring of the second ligand. Because the deuterium-containing alkyl group is an electron-donating group, its introduction into the pyridine ring can increase the electron density of the pyridine ring. This increases the HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital) levels of the organometallic complex. Using such an organometallic complex with a high HOMO level as the light-emitting material 119 for the light-emitting layer can reduce the hole injection barrier in the light-emitting layer 113, facilitating the entry of holes into the light-emitting layer 113, thereby reducing the driving voltage of the light-emitting device 10. Therefore, the load applied to the light emitting device 10 during driving can be reduced, and the reliability of the light emitting device can be improved.

[0046] Furthermore, the introduction of an alkyl group having deuterium into the organometallic complex enables the control of the emission characteristics of the organometallic complex. In the organometallic complex of one embodiment of the present invention, the alkyl group having deuterium is bonded to the carbon at the 5-position of the pyridine ring of the second ligand, which can prevent the expansion of the π-conjugated system between the pyridine ring and the phenyl group, thereby enabling the emission color of the organometallic complex to have a shorter wavelength.

[0047] In the organometallic complex of one embodiment of the present invention, a deuterium-containing alkyl group is preferably bonded to the carbon of each pyridine ring. The bond dissociation energy of the carbon-deuterium bond is greater than the bond dissociation energy of the carbon-proton bond, making the bond more stable and less likely to break. Therefore, by introducing an alkyl group having deuterium into a ligand, the ligand can be made more stable than when an alkyl group not having deuterium is introduced. Note that in this specification and the like, hydrogen includes protons and deuterium. Deuterium refers to a stable isotope of hydrogen with a mass number of 2. Proton refers to a stable isotope of hydrogen with a mass number of 1.

[0048] In the organometallic complex of one embodiment of the present invention, if the number of carbon atoms in the alkyl group bonded to the carbon of the pyridine ring is too large, the sublimability may decrease. Therefore, in order to prevent a decrease in the sublimability of the organometallic complex, the number of carbon atoms in the alkyl group having deuterium introduced into the pyridine ring is preferably 1 to 6, as described above.

[0049] In the organometallic complex of one embodiment of the present invention, each pyridine ring has an alkyl group having deuterium, which can suppress intermolecular interactions. For example, in the light-emitting layer 113 shown in FIG. 1B, by using an organometallic complex having the above structure as the light-emitting material 119, interaction between the light-emitting material 119 and the host material 118 (either or both of the organic compound 118_1 and the organic compound 118_2) can be prevented, thereby improving the emission efficiency of the light-emitting device 10.

[0050] <Examples of organometallic complexes> Hereinafter, an organometallic complex according to one embodiment of the present invention will be described using a general formula.

[0051] One embodiment of the present invention is an organometallic complex represented by the general formula (Ga).

[0052] [ka]

[0053] In the organometallic complex represented by the general formula (Ga), R 1 ~R 21 each independently represents a deuterium-containing alkyl group having 1 to 6 carbon atoms or hydrogen (including deuterium); and n represents 1 or 2.

[0054] In general formula (Ga), the ligand shown on the left side is the first ligand described above, and the ligand shown on the right side is the second ligand described above. 1 ~R 4 is the pyridine ring of the first ligand, and R 5 ~R 8 is the benzene ring of the first ligand, and R 9 ~R 13 is the benzofuro[2,3-b]pyridine ring of the second ligand, and R 14 ~R 16 The pyridine ring having R 17 ~R 21 is a phenyl group bonded to the carbon atom at the 4-position of the pyridine ring of the second ligand. As described above, as in the organometallic complex of general formula (Ga), a structure in which a phenyl group is bonded to the carbon atom at the 4-position of the pyridine ring of the second ligand is formed, and the second ligand is extended, thereby enhancing the planarity of the metal complex. Therefore, by using such an organometallic complex as the light-emitting material 119, the transition dipole moment involved in the light emission of the light-emitting material 119 is more likely to be oriented, thereby producing anisotropy in the light emission from the light-emitting layer.

[0055] One embodiment of the present invention is an organometallic complex represented by General Formula (Gb).

[0056] [ka]

[0057] In the organometallic complex represented by the general formula (Gb), R 1 , R 13 and R 14 each independently represents a deuterium-containing alkyl group having 1 to 6 carbon atoms; R 2 ~R 12 and R 15 ~R 21 each independently represents a deuterium-containing alkyl group having 1 to 6 carbon atoms or hydrogen (including deuterium); and n represents 1 or 2.

[0058] General formula (Gb) is R in general formula (Ga). 1 , R 13 and R 14 is a general formula in which R is limited to an alkyl group having 1 to 6 carbon atoms and having a deuterium. 1 is an alkyl group having a deuterium bonded to the carbon atom at the 5-position of the pyridine ring of the first ligand, and R 13 is an alkyl group having a deuterium bonded to the carbon atom at the 2-position of the benzofuro[2,3-b]pyridine ring of the second ligand, and R 14 is a deuterium-containing alkyl group bonded to the 5-position carbon of the pyridine ring of the second ligand. As described above, introducing a deuterium-containing alkyl group into an organometallic complex in this manner can increase the HOMO level and LUMO level of the organometallic complex. Using such an organometallic complex with a high HOMO level as the light-emitting material 119 of the light-emitting layer can reduce the hole injection barrier in the light-emitting layer 113, making it easier for holes to enter the light-emitting layer 113, thereby reducing the driving voltage of the light-emitting device 10. This reduces the load applied to the light-emitting device 10 during operation and improves the reliability of the light-emitting device. Furthermore, as described above, introducing a deuterium-containing alkyl group into an organometallic complex can adjust the light-emitting properties of the organometallic complex. Furthermore, as described above, introducing a deuterium-containing alkyl group into an organometallic complex can suppress intermolecular interactions, and using such an organometallic complex can improve the luminous efficiency of the light-emitting device.

[0059] One embodiment of the present invention is an organometallic complex represented by General Formula (G1).

[0060] [ka]

[0061] In the organometallic complex represented by general formula (G1), R 1 , R 13 and R 14 each independently represents a deuterium-containing alkyl group having 1 to 6 carbon atoms; R 2 ~R 12 each independently represents a deuterium-containing alkyl group having 1 to 6 carbon atoms or hydrogen (including deuterium), and R 15 ~R 21 each independently represents hydrogen (including deuterium), and n represents 1 or 2.

[0062] General formula (G1) is a general formula (Gb) in which R of the pyridine ring of the second ligand is 15 and R 16 and R of the phenyl group bonded to the carbon atom at the 4th position of the pyridine ring. 17 ~R 21 is a general formula limited to hydrogen (including deuterium). 15 ~R 21 By limiting the number of atoms to hydrogen (including deuterium), the stability of the organometallic complex in the excited state can be further improved. Therefore, using such an organometallic complex as the light-emitting material 119 can improve the reliability of the light-emitting device 10, which is more preferable.

[0063] Another embodiment of the present invention is an organometallic complex represented by General Formula (G2).

[0064] [ka]

[0065] In the organometallic complex represented by general formula (G2), R 2 ~R12 each independently represents a deuterium-containing alkyl group having 1 to 6 carbon atoms or hydrogen (including deuterium), and R 15 ~R 21 each independently represents hydrogen (including deuterium), and n represents 1 or 2.

[0066] General formula (G2) is the same as R in general formula (G1). 1 , R 13 and R 14 The general formula is limited to the methyl-d3 group (-CD3). Introducing a group in which all hydrogen atoms are deuterated, such as the methyl-d3 group, is preferable because it can further increase the stability of the organometallic complex. Furthermore, the methyl-d3 group is more preferable because it allows for the synthesis of organometallic complexes more inexpensively than alkyl groups with two or more carbon atoms containing deuterium.

[0067] Furthermore, in the organometallic complexes represented by the general formulae (G1) and (G2), when n is 2 (i.e., when the first ligands are present twice as frequently as the second ligands), the planarity of the organometallic complex is increased as described above, and therefore, by using the organometallic complex as the light-emitting material 119, the vector connecting the two most distant atoms of the light-emitting material 119 is likely to be oriented parallel to the substrate in the light-emitting layer 113. Furthermore, the transition dipole moment involved in the light emission of the organometallic complex is likely to be parallel to this vector, and therefore, by using such an organometallic complex as the light-emitting material 119, the transition dipole moment of the light-emitting material 119 is likely to be oriented parallel to the substrate, thereby improving the light extraction efficiency (χ) of the light-emitting device 10.

[0068] Next, specific examples of substituents that can be applied to the organometallic complexes represented by the above general formula will be described. Note that in the specific examples of substituents described below, unless otherwise specified, some or all of the hydrogen atoms may be deuterium atoms. Furthermore, the substituents that can be applied to the above general formula are not limited to the specific examples described below.

[0069] <Alkyl group having 1 to 6 carbon atoms and deuterium> The deuterium-containing alkyl group having 1 to 6 carbon atoms refers to a monovalent group formed by removing one hydrogen atom from an alkane having 1 to 6 carbon atoms, and at least one of the remaining hydrogen atoms is a deuterium atom. Specific examples of the deuterium-containing alkyl group having 1 to 6 carbon atoms include methyl-d3 group (-CD3), ethyl-d5 group, propyl-d7 group, isopropyl-1-d group, isopropyl-d7 group, butyl-d9 group, isobutyl-1,1-d2 group, isobutyl-d9 group, sec-butyl-d9 group, tert-butyl-d9 group, pentyl-d 11 Group, isopentyl-d 11 Group, hexyl-d 13 Examples of such groups include the methyl-d group, neopentyl-1,1-d group, and isohexyl-d group. In particular, groups in which all hydrogen atoms are deuterated, such as the methyl-d group, are preferred because they can further enhance the stability of organometallic complexes. Furthermore, the methyl-d group is preferred because it allows organometallic complexes to be synthesized more inexpensively than alkyl groups having two or more carbon atoms and deuterium.

[0070] <<Example>> Next, specific examples of the organometallic complex of one embodiment of the present invention represented by the above general formula are shown below. Note that the organometallic complex of one embodiment of the present invention is not limited to the examples shown below.

[0071] [ka]

[0072] [ka]

[0073] [ka]

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[0075] <Method for synthesizing organometallic complexes> Next, a method for synthesizing an organometallic complex represented by the following general formula (G1) will be described. Various reactions can be applied to synthesize the organometallic complex. For example, the organometallic complex represented by the general formula (G1) can be synthesized by the following simple synthesis scheme.

[0076] [ka]

[0077] In the organometallic complex represented by general formula (G1), R 1 , R 13 and R 14 each independently represents a deuterium-containing alkyl group having 1 to 6 carbon atoms; R 2 ~R 12 each independently represents a deuterium-containing alkyl group having 1 to 6 carbon atoms or hydrogen (including deuterium), and R 15 ~R 21 each independently represents hydrogen (including deuterium), and n represents 1 or 2.

[0078] <<Method for synthesizing compound (a1)>> First, an example of a method for synthesizing compound (a1), which functions as a ligand in an organometallic complex represented by general formula (G1), will be described. Note that compound (a1) represents the same groups as those described above for general formula (G1), and therefore the description thereof will be omitted here.

[0079] [ka]

[0080] Various reactions can be used to synthesize compound (a1). For example, as shown in the following synthesis scheme (A-1), boron compound (a1-1) is coupled with halogen compound (a1-2) to synthesize halogen compound (a1-3), and then, as shown in scheme (A-2), halogen compound (a1-3) is coupled with boron compound (a1-4) to synthesize the target compound (a1). These reactions can be performed using a metal catalyst in the presence of a base, such as the Suzuki-Miyaura reaction. In schemes (A-1) and (A-2), deuteration can also be achieved by stirring the organic compound in a deuterated solvent in the presence of a base.

[0081] [ka]

[0082] In the above synthesis scheme (A-1) and synthesis scheme (A-2), R 9 ~R 21 represents the same group as the group described in the explanation of general formula (G1) above, and therefore will not be described here. Y represents a boronate ester such as boronic acid or pinacol boron. X represents either chlorine, bromine, iodine, or a sulfonyloxy group, and using one with a larger atomic number is preferred because it increases reactivity. Alternatively, X may be a boronate ester such as boronic acid or pinacol boron, and Y may be a halogen or sulfonyloxy group, and these may be reacted.

[0083] In the above synthesis schemes (A-1) and (A-2), when the Suzuki-Miyaura reaction is performed using a palladium catalyst, palladium compounds such as tetrakis(triphenylphosphine)palladium(0), palladium(II) acetate, and tris(dibenzylideneacetone)dipalladium(0) and ligands such as 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl can be used. Inorganic bases such as potassium carbonate, sodium carbonate, and tripotassium phosphate can also be used. Solvents such as toluene, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, and water can also be used. However, the reagents that can be used in this reaction are not limited to these.

[0084] In the above synthesis schemes (A-1) and (A-2), R 13 and R 14 Each of R independently represents a deuterium-containing alkyl group having 1 to 6 carbon atoms. Therefore, the synthesis schemes (A-1) and (A-2) are synthesis methods in which a reaction is carried out using a raw material that has been deuterated in advance, but the synthesis method is not limited thereto. For example, in the synthesis schemes (A-1) and (A-2), R 13 and R 14 may be an alkyl group not having a deuterium atom. In this case, after the reactions shown in the synthesis schemes (A-1) and (A-2), R 13 and R 14 R 13 and R 14 When deuterium is added by HD exchange reaction, inorganic bases such as sodium tert-butoxide, sodium ethoxide, sodium carbonate, etc. can be used. In addition, deuterated solvents such as dimethyl sulfoxide-d6, deuterated ethanol, heavy water, etc. can be used. However, the reagents that can be used in this reaction are not limited to these.

[0085] In addition, after the above synthesis scheme (A-1) and synthesis scheme (A-2), R 9 ~R20 When deuteration is performed by the HD exchange reaction, the target product can be obtained by reacting in a heavy solvent using a transition metal as a catalyst. Reaction conditions include a hydrogen atmosphere, high temperature, and high pressure, and can be appropriately selected. Examples of transition metals that can be used include platinum group carbon catalysts (Pd / C, Pt / C, Rh / C, Ru / C), chloroplatinic acid, and platinum dioxide. While deuterium oxide is preferred as the heavy solvent, other heavy solvents that can be used include deuterated benzene, deuterated acetone, and deuterated ethanol. The reagents that can be used in this reaction are not limited to these.

[0086] <<Method for synthesizing organometallic complex represented by general formula (G1)>> The following synthesis scheme (A-3) shows a synthesis method for an organometallic complex represented by general formula (G1) when n is 2, and synthesis scheme (A-4) shows a synthesis method for an organometallic complex represented by general formula (G1) when n is 1. As shown in synthesis scheme (A-3), a dinuclear complex (a2) having a halogen-bridged structure is reacted with compound (a1) in an inert gas atmosphere to obtain an organometallic complex represented by general formula (G1) (when n is 2). Also, as shown in synthesis scheme (A-4), a dinuclear complex (a3) having a halogen-bridged structure is reacted with compound (a4) in an inert gas atmosphere to obtain an organometallic complex represented by general formula (G1) (when n is 1).

[0087] [ka]

[0088] [ka]

[0089] In the synthetic scheme (A-3) and the synthetic scheme (A-4), R 1 ~R 21represents the same group as the group described in the above general formula (G1), and therefore will not be described here. X represents a halogen atom.

[0090] Note that the organometallic complex obtained by the reaction shown in Synthesis Scheme (A-3) or (A-4) may be further irradiated with light or heat to cause a reaction, thereby producing isomers such as geometric isomers and optical isomers. These isomers are also organometallic complexes represented by General Formula (G1), which is one embodiment of the present invention.

[0091] Alternatively, the organometallic complex represented by general formula (G1) (where n is 2) may be obtained by reacting a dinuclear complex (a2) having a halogen-bridged structure with a dechlorinating agent such as silver trifluoromethanesulfonate to precipitate silver chloride, and then reacting the supernatant with compound (a1) in an inert gas atmosphere. Alternatively, the organometallic complex represented by general formula (G1) (where n is 1) may be obtained by reacting a dinuclear complex (a3) having a halogen-bridged structure with a dechlorinating agent such as silver trifluoromethanesulfonate to precipitate silver chloride, and then reacting the supernatant with compound (a4) in an inert gas atmosphere.

[0092] Although an example of a method for synthesizing an organometallic complex, which is a compound of one embodiment of the present invention, has been described above, the present invention is not limited thereto, and any other synthesis method may be used for synthesis.

[0093] [Molecular Orientation Parameter] Here, we will explain the molecular orientation parameter. The molecular orientation parameter a is a value that estimates the molecular orientation from the light-emitting state of the light-emitting device. The radiation angle dependence (spatial light-emitting pattern) of the light-emitting device's light-emitting intensity reflects the spatial distribution of the transition dipole of the light-emitting material. The orientation state of the light-emitting device can be investigated by analyzing this spatial distribution. This method observes and analyzes the light-emitting device's light emission itself, so as long as the light-emitting material 119 is emitting light, it is possible to investigate the orientation state of the light-emitting material 119 in relation to the light-emitting surface and the transition dipole moment, even if the light-emitting material 119 is dispersed in a host material in the light-emitting layer 113 and its concentration is low.

[0094] When the organometallic complex of one embodiment of the present invention is used as the light-emitting material 119 of the light-emitting device 10, it is particularly preferable to use an organometallic complex having a molecular orientation parameter a of 0.30 or less, preferably 0.28 or less, of light emitted from the light-emitting device 10. Such an organometallic complex has favorable orientation properties, and therefore can increase the light extraction efficiency of the light-emitting device 10, thereby enabling the light-emitting device to have favorable luminous efficiency.

[0095] <Calculation method of molecular orientation parameter a> The following describes a method for calculating the molecular orientation parameter a of light emitted from the light-emitting device 10. By comparing the angular dependence of the measured light-emitting device's light-emitting intensity with the calculated value of the angular dependence of the light-emitting intensity calculated using a device simulator assuming a parameter a (see formula (1) below) that represents the orientation of the light-emitting material 119, it is possible to estimate a reasonable value for the molecular orientation parameter a for the measured light-emitting device and investigate the orientation state of the light-emitting material in the light-emitting device (see non-patent document 1).

[0096] The inventors also focused on the shape of the emission spectrum obtained from the device simulator, and compared the measured and calculated values for the emission spectrum shape and the change in the shape of the emission spectrum depending on the angle, and performed a match. Furthermore, the emission intensity used in the measurements and calculations is the area intensity of the emission spectrum, rather than the emission intensity of a specific wavelength. These newly applied techniques by the inventors enable highly accurate estimation of the parameter a, unlike Non-Patent Document 1.

[0097] Figure 3 shows the relationship between the observation direction of the detector in measuring the spatial distribution of luminescence intensity and each vector component of the transition dipole moment on the substrate. Because the transition dipole moment is a vector, it can be combined and decomposed, and the average transition dipole moment in the luminescent material 119 in the luminescent layer 113 can be decomposed into the mutually orthogonal components in the x-axis direction (TEh component), y-axis direction (TMh component), and z-axis direction (TMv component).

[0098] As mentioned above, it is known that light emitted from the light-emitting material 119 is emitted in a direction perpendicular to the transition dipole moment (any direction within a perpendicular plane). Of the components divided in the above three directions, the TEh component and the TMh component (x-axis direction and y-axis direction) have transition dipole moments parallel to the substrate, so their emission direction is perpendicular to the substrate and they can be said to be components that exhibit light emission that is easy to extract. On the other hand, the TMv component (z-axis direction) has a transition dipole moment perpendicular to the substrate, so its emission direction is parallel to the substrate and they are components that exhibit light emission that is difficult to extract.

[0099] In Figure 3, the figures emerging from the center of the arrows representing the vectors of each component are schematic diagrams showing the emission intensity entering the detector in the direction when the detector direction is changed from directly in front of the substrate (θ = 0 degrees) to almost parallel to the substrate (θ = 90 degrees), and the linear distance from the center is proportional to the intensity.

[0100] For the TEh component, the detector is located in the direction in which the light is emitted, so even if the angle θ of the detector relative to the substrate is changed, the intensity of the detected light (that is, the linear distance from the center of the arrow in the figure) remains constant, and the figure emanating from the center of the arrow in the figure shows a fan shape. On the other hand, the figures emanating from the center of the arrow in the figure for the TMh and TMv components are distorted, indicating that the intensity of the detected light changes significantly depending on the angle θ of the detector relative to the substrate. As shown in the figure, the TMh component has a strong intensity when observed in an area where θ is small, and the TMv component has a strong intensity when observed in an area where θ is large. At this time, the emission intensity measured by the detector (emission intensity for wavelength λ at a certain angle θ: I λ (θ, λ) can be expressed as equation (1).

[0101]

number

[0102] In the formula I TMv , I TMh , I TEh represents the spatial intensity distribution of light emitted from the transition dipole in the configuration shown in Figure 3, where a represents the proportion of transition dipole moments (TMv components) aligned perpendicular to the substrate. On the other hand, 1-a represents the proportion of transition dipole moments (TMh components, TEh components) aligned parallel to the substrate. In other words, a can be considered a parameter that represents the orientation of the transition dipole of the luminescent molecule.

[0103] In the formula, if the transition dipole moment is aligned only in a direction completely parallel to the substrate, there will be no TMv component, so a = 0. On the other hand, if the transition dipole moment is aligned only in a direction perpendicular to the substrate, a = 1. Furthermore, if the transition dipole moment is aligned randomly, the transition dipole moment is considered to be isotropic with a 1:1:1 ratio relative to the x-axis, y-axis, and z-axis. Therefore, the ratio of the component perpendicular to the substrate (TMv component) to the components parallel to the substrate (TMh component and TEh component) is 1:2, so a = 1 / 3 (approximately 0.33).

[0104] Here, as mentioned above, I TEh The intensity of is constant regardless of the angle, but I TMv , I TMh As mentioned above, the magnitude of a changes depending on the angle (θ) of the substrate relative to the measuring instrument. Therefore, by measuring the emission intensity while changing θ, the value of a can be obtained from the change in intensity relative to θ.

[0105] In addition, the intensity does not change depending on the angle. TEh However, the amplitude direction of the electric field of the emitted light is the same as the direction of the transition dipole moment, so I TEh is S wave, I TMv , I TMh Since is a P wave, it is possible to measure it by removing the TEh component by inserting a linear polarizer in the direction perpendicular to the substrate surface.

[0106] Furthermore, comparing the TMv and TMh components, the TMh component emits light primarily perpendicular to the substrate, while the TMv component emits light primarily parallel to the substrate. However, in light-emitting devices that utilize solid-state light emission, much of the TMv component's light undergoes total internal reflection and cannot be extracted. On the other hand, the TMh component's light is more easily extracted than the TMv component. Furthermore, in light-emitting devices with optically optimized film thicknesses, the TMh component's light emission, which is primarily perpendicular to the substrate, is enhanced by interference, resulting in a higher luminescence intensity for the TMh component (thus maximizing the luminescence efficiency). In other words, unless the molecular orientation parameter a is extremely close to 1, a significant difference in the luminescence intensities of the TMv and TMh components occurs in light-emitting devices with optically optimized film thicknesses. In other words, in light-emitting devices with maximized luminescence efficiency, most of the observed light is from the Th component. In this way, when the difference in emission intensity between the TMv and TMH components is large, it is difficult to experimentally extract the contribution of the component with the smaller intensity (the TMv component in this case) from the angular distribution of emission intensity.

[0107] Therefore, we prepare a light-emitting device for orientation measurement with an adjusted film thickness to minimize the front-facing luminescence intensity by utilizing the interference effect (i.e., minimize the luminescence of the TMH component by utilizing optical interference). This allows for easier determination of the value of a. Specifically, we fabricate a light-emitting device with reduced front-facing luminance by setting the distance between the luminescent region and the cathode to half nλ (nλ / 2), and then use this device for measurements. Film thickness adjustment is typically achieved by thickening the electron transport layer to which an alkali metal is added. However, due to limitations in the film's conductivity, this can easily lead to increased drive voltage and disruption of the carrier balance. Therefore, for this film thickness adjustment, it is preferable to use a composite material in which a hole-transporting material and a material exhibiting acceptor properties are added to the hole-transporting material.

[0108] The composite material can be the same as the composite material preferably used for the hole injection layer described later in Embodiment 2. In the alignment measurement device, it is preferable to use molybdenum oxide as the acceptor material in order to suppress an increase in driving voltage.

[0109] [Computational chemistry] Next, a method for investigating, using computational chemistry, conditions for aligning the transition dipole moment involved in light emission of an organometallic complex of one embodiment of the present invention parallel to the substrate will be described.

[0110] In the calculation, first, vector A is defined as connecting the two atoms that are farthest apart in the lowest triplet excited state of the organometallic complex. Then, plane A is defined as a plane that contains vector A and that, when the group of atoms that make up the organometallic complex is projected perpendicularly onto the plane, results in the largest area of the quadrangle that encloses the projected group of atoms of the organometallic complex. Plane B is defined as a plane that is perpendicular to plane A and contains vector A. Vector B is defined as the transition dipole moment involved in the emission of the organometallic complex. The vector obtained by projecting vector B onto plane B is defined as vector B'. (However, the direction of vector A is determined so that the angle it forms with vector B is 90° or less.)

[0111] In organometallic complexes, a large vector B is considered to be advantageous for improving the luminescence quantum yield. That is, a larger vector B, specifically, a vector B of 0.5 debye or more as defined above, is more preferable because it can improve the luminescence quantum yield.

[0112] Furthermore, it is believed that a small angle (φ) between vector A and vector B' is advantageous for molecular orientation. In other words, when an organometallic complex having a smaller angle (φ) between vector A and vector B', specifically an angle of 25° or less between vector B' and vector A as defined above, is used as light-emitting material 119, the organometallic complex is more likely to be oriented parallel to the substrate, which is more preferable.

[0113] Furthermore, it is more preferable that vector B is large and the angle (φ) between vector A and vector B' is small. Therefore, when the dot product of vector A and vector B is calculated using the magnitude of vector A, the magnitude of vector B, and φ, as (magnitude of vector A (nm)) × (magnitude of vector B (debye)) × cosφ, organometallic complexes with a larger dot product are more preferable because they have a higher luminescence quantum yield and are more likely to be oriented parallel to the substrate. Using an organometallic complex with a dot product of 1.00 or more increases the light extraction efficiency of light-emitting device 10, making it possible to achieve a light-emitting device with good luminous efficiency.

[0114] Detailed calculation methods for vector A, vector B, θ, inner product, etc. will be explained in detail in the sixth embodiment.

[0115] Note that the compound described in this embodiment can be used in appropriate combination with any of the structures described in other embodiments.

[0116] (Embodiment 2) In this embodiment, a structure of a light-emitting device of one embodiment of the present invention will be described with reference to FIGS.

[0117] [Basic structure of light-emitting devices] The basic structure of a light-emitting device will be described. Figure 4(A) shows a light-emitting device having a structure (single structure) in which an organic compound layer including a light-emitting layer is disposed between a pair of electrodes. Specifically, the light-emitting device has a structure in which an organic compound layer 103 is sandwiched between a first electrode 101 and a second electrode 102.

[0118] 4B shows a light-emitting device with a stacked structure (tandem structure) having multiple (two in FIG. 4B) organic compound layers (103a, 103b) between a pair of electrodes and a charge generation layer 106 between the organic compound layers. A light-emitting device with a tandem structure can realize a highly efficient light-emitting device without changing the amount of current.

[0119] The charge generation layer 106 has a function of injecting electrons into one organic compound layer (103a or 103b) and injecting holes into the other organic compound layer (103b or 103a) when a potential difference is generated between the first electrode 101 and the second electrode 102. Therefore, in FIG. 4B, when a voltage is applied to the first electrode 101 so that the potential thereof is higher than that of the second electrode 102, electrons are injected from the charge generation layer 106 into the organic compound layer 103a and holes are injected into the organic compound layer 103b.

[0120] From the viewpoint of light extraction efficiency, the charge generation layer 106 is preferably transparent to visible light (specifically, the visible light transmittance of the charge generation layer 106 is 40% or more). The charge generation layer 106 functions even if it has lower conductivity than the first electrode 101 and the second electrode 102.

[0121] FIG. 4C shows a stacked structure of the organic compound layer 103 of the light-emitting device according to one embodiment of the present invention. In this case, the first electrode 101 functions as an anode, and the second electrode 102 functions as a cathode. The organic compound layer 103 has a structure in which a hole injection layer 111, a hole transport layer 112, a light-emitting layer 113, an electron transport layer 114, and an electron injection layer 115 are sequentially stacked over the first electrode 101. The light-emitting layer 113 may have a stacked structure of a plurality of light-emitting layers emitting different light colors. For example, a light-emitting layer containing a red light-emitting material, a light-emitting layer containing a green light-emitting material, and a light-emitting layer containing a blue light-emitting material may be stacked, or a layer containing a carrier-transporting material may be interposed between the light-emitting layers. Alternatively, a light-emitting layer containing a yellow light-emitting material and a light-emitting layer containing a blue light-emitting material may be combined. However, the stacked structure of the light-emitting layer 113 is not limited to the above. For example, the light-emitting layer 113 may have a structure in which multiple light-emitting layers emitting the same light-emitting color are stacked. For example, a first light-emitting layer containing a blue light-emitting material and a second light-emitting layer containing a blue light-emitting material may be stacked, or a layer containing a carrier-transporting material may be interposed between the layers. A structure in which multiple light-emitting layers emitting the same light-emitting color are stacked may have higher reliability than a single-layer structure. Even in a tandem structure such as that shown in FIG. 4B, in which multiple organic compound layers are included, each organic compound layer is stacked in order from the anode side as described above. Furthermore, when the first electrode 101 is a cathode and the second electrode 102 is an anode, the stacking order of the organic compound layers 103 is reversed. Specifically, the structure is such that 111 on the first electrode 101, which is a cathode, is an electron injection layer, 112 is an electron transport layer, 113 is a light-emitting layer, 114 is a hole transport layer, and 115 is a hole injection layer.

[0122] The light-emitting layers 113 included in the organic compound layers (103, 103a, 103b) each contain a light-emitting material and a combination of multiple substances, and can be configured to emit fluorescent or phosphorescent light of a desired emission color. The light-emitting layer 113 may also have a stacked structure that emits different light colors. In this case, different materials may be used as the light-emitting material and other substances for each stacked light-emitting layer. Alternatively, a structure in which different light-emitting colors are emitted from the multiple organic compound layers (103a, 103b) shown in Figure 4(B) may also be used. In this case, different materials may be used as the light-emitting material and other substances for each light-emitting layer.

[0123] In addition, in a light-emitting device according to one embodiment of the present invention, for example, the first electrode 101 shown in FIG. 4C may be a reflective electrode, the second electrode 102 may be a semi-transmissive and semi-reflective electrode, and a micro-optical resonator (microcavity) structure may be formed. This allows light emitted from the light-emitting layer 113 included in the organic compound layer 103 to resonate between the two electrodes, thereby enhancing the intensity of light emitted from the second electrode 102. This makes it easy to achieve high definition. Furthermore, the intensity of light emitted from a specific wavelength in the front direction can be enhanced, thereby reducing power consumption.

[0124] When the first electrode 101 of the light-emitting device is a reflective electrode having a laminated structure of a reflective conductive material and a light-transmitting conductive material (transparent conductive film), optical adjustment can be performed by controlling the film thickness of the transparent conductive film. Specifically, it is preferable to adjust the optical distance (product of film thickness and refractive index) between the first electrode 101 and the second electrode 102 to mλ / 2 (where m is an integer of 1 or greater) or in the vicinity thereof, for the wavelength λ of light obtained from the light-emitting layer 113.

[0125] Furthermore, in order to amplify the desired light (wavelength: λ) obtained from the light-emitting layer 113, it is preferable to adjust the optical distance from the first electrode 101 to the region (light-emitting region) in the light-emitting layer 113 where the desired light is obtained and the optical distance from the second electrode 102 to the region (light-emitting region) in the light-emitting layer 113 where the desired light is obtained to be (2m'+1)λ / 4 (where m' is an integer of 1 or greater) or close to that. Note that the light-emitting region here refers to the recombination region of holes and electrons in the light-emitting layer 113.

[0126] By performing such optical adjustment, the spectrum of the specific monochromatic light obtained from the light-emitting layer 113 can be narrowed, and light emission with good color purity can be obtained.

[0127] In the above case, the optical distance between the first electrode 101 and the second electrode 102 can be strictly defined as the total thickness from the reflective region of the first electrode 101 to the reflective region of the second electrode 102. However, since it is difficult to precisely determine the reflective regions of the first electrode 101 and the second electrode 102, the above-mentioned effect can be sufficiently achieved by assuming any position of the first electrode 101 and the second electrode 102 as the reflective region. Furthermore, the optical distance between the first electrode 101 and the light-emitting layer from which desired light is obtained can be strictly defined as the optical distance between the reflective region of the first electrode 101 and the light-emitting region of the light-emitting layer from which desired light is obtained. However, since it is difficult to precisely determine the reflective region of the first electrode 101 and the light-emitting region of the light-emitting layer from which desired light is obtained, the above-mentioned effect can be sufficiently achieved by assuming any position of the first electrode 101 as the reflective region and any position of the light-emitting layer from which desired light is obtained as the light-emitting region.

[0128] 4(D) shows a modified example of the stacked layer structure shown in FIG. 4(C). In this case, too, the first electrode 101 functions as an anode, and the second electrode 102 functions as a cathode. This modified example shows a case where a hole blocking layer and an electron blocking layer are provided. That is, the organic compound layer 103 has a structure in which a hole injection layer 111, a hole transport layer 112, an electron blocking layer 116, a light-emitting layer 113, a hole blocking layer 117, an electron transport layer 114, and an electron injection layer 115 are sequentially stacked on the first electrode 101.

[0129] The electron blocking layer 116 is provided, for example, for the purpose of preventing electrons from passing through from the light-emitting layer 113 to the first electrode 101 side. The hole blocking layer 117 is provided, for example, for the purpose of preventing holes from passing through from the light-emitting layer 113 to the second electrode 102 side. The electron blocking layer 116 can also be considered as part of the hole transport layer 112. The hole blocking layer 117 can also be considered as part of the electron transport layer 114.

[0130] The light-emitting device shown in Figure 4(E) has a tandem structure. The tandem structure allows the device to emit light with high brightness. Furthermore, the tandem structure can reduce the current required to obtain the same brightness compared to a single structure, thereby improving reliability. Furthermore, power consumption can be reduced.

[0131] The light-emitting device shown in FIG. 4(F) is an example of the tandem-structure light-emitting device shown in FIG. 4(B). As shown in the figure, the light-emitting device has a structure in which three organic compound layers (103a, 103b, 103c) are stacked with charge generation layers (106a, 106b) sandwiched between them. Each of the three organic compound layers (103a, 103b, 103c) has a light-emitting layer (113a, 113b, 113c), and the light-emitting colors of the light-emitting layers can be freely combined. For example, the light-emitting layer 113a can be blue, the light-emitting layer 113b can be red, green, or yellow, and the light-emitting layer 113c can be blue. Alternatively, the light-emitting layer 113a can be red, the light-emitting layer 113b can be blue, green, or yellow, and the light-emitting layer 113c can be red.

[0132] In the light-emitting device according to one embodiment of the present invention, at least one of the first electrode 101 and the second electrode 102 is a light-transmitting electrode (such as a transparent electrode or a semi-transmitting / semi-reflective electrode). When the light-transmitting electrode is a transparent electrode, the visible light transmittance of the transparent electrode is 40% or more. In addition, when the semi-transmitting / semi-reflective electrode is used, the visible light reflectance of the semi-transmitting / semi-reflective electrode is 20% or more and 80% or less, preferably 40% or more and 70% or less. Furthermore, these electrodes have a resistivity of 1×10 -2 It is preferable to set it to Ωcm or less.

[0133] In the above-described light-emitting device according to one embodiment of the present invention, when one of the first electrode 101 and the second electrode 102 is a reflective electrode (a reflective electrode), the reflectivity of the reflective electrode for visible light is set to 40% to 100%, preferably 70% to 100%. -2 It is preferable to set it to Ωcm or less.

[0134] [Specific structure of light-emitting device] Next, a specific structure of a light-emitting device according to one embodiment of the present invention will be described. Here, a description will be given using FIG. 4E, which has a tandem structure. The single-structure light-emitting devices shown in FIGS. 4A and 4C also have the same organic compound layer structure. When the light-emitting device shown in FIG. 4E has a microcavity structure, the first electrode 101 is formed as a reflective electrode, and the second electrode 102 is formed as a semi-transmissive and semi-reflective electrode. Therefore, a single or multiple desired electrode materials can be used to form a single layer or a stacked layer. The second electrode 102 is formed by selecting an appropriate material after the organic compound layer 103b is formed.

[0135] [Light-emitting device materials] <First electrode and second electrode> The materials forming the first electrode 101 and the second electrode 102 can be any combination of the following materials, as long as they fulfill the functions of both electrodes described above. For example, metals, alloys, electrically conductive compounds, and mixtures thereof can be used. Specific examples include In-Sn oxide (also referred to as ITO), In-Si-Sn oxide (also referred to as ITSO), In-Zn oxide, and In-W-Zn oxide. Other metals that can be used include aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), and neodymium (Nd), as well as alloys containing any combination of these metals. Other examples that can be used include elements belonging to Group 1 or 2 of the periodic table (e.g., lithium (Li), cesium (Cs), calcium (Ca), and strontium (Sr)), rare earth metals such as europium (Eu) and ytterbium (Yb), and alloys containing appropriate combinations of these elements, as well as graphene.

[0136] 4(E), when the first electrode 101 is an anode, the hole injection layer 111a and the hole transport layer 112a of the organic compound layer 103a are sequentially laminated by vacuum evaporation on the first electrode 101. After the organic compound layer 103a and the charge generation layer 106 are formed, the hole injection layer 111b and the hole transport layer 112b of the organic compound layer 103b are similarly sequentially laminated on the charge generation layer 106.

[0137] Furthermore, in each light-emitting device shown in Figure 4, the first electrode 101 is a reflective electrode, the second electrode 102 is a semi-transparent and semi-reflective electrode, and a micro-optical resonator (microcavity) structure is formed, whereby the light emitted from the light-emitting layer 113 contained in the organic compound layer 103 is resonated between the two electrodes, thereby enhancing the light emitted from the second electrode 102.

[0138] When the first electrode 101 of the light-emitting device is a reflective electrode having a laminated structure of a reflective conductive material and a light-transmitting conductive material (transparent conductive film), optical adjustment can be performed by controlling the film thickness of the transparent conductive film. Specifically, it is preferable to adjust the optical distance (product of film thickness and refractive index) between the first electrode 101 and the second electrode 102 to mλ / 2 (where m is an integer of 1 or greater) or in the vicinity thereof, for the wavelength λ of light obtained from the light-emitting layer 113.

[0139] Furthermore, in order to amplify the desired light (wavelength: λ) obtained from the light-emitting layer 113, it is preferable to adjust the optical distance from the first electrode 101 to the region (light-emitting region) in the light-emitting layer 113 where the desired light is obtained and the optical distance from the second electrode 102 to the region (light-emitting region) in the light-emitting layer 113 where the desired light is obtained to be (2m'+1)λ / 4 (where m' is an integer of 1 or greater) or close to that. Note that the light-emitting region here refers to the recombination region of holes and electrons in the light-emitting layer 113.

[0140] By performing such optical adjustment, the spectrum of the specific monochromatic light obtained from the light-emitting layer 113 can be narrowed, and light emission with good color purity can be obtained.

[0141] In the above case, the optical distance between the first electrode 101 and the second electrode 102 can be strictly defined as the total thickness from the reflective region of the first electrode 101 to the reflective region of the second electrode 102. However, since it is difficult to precisely determine the reflective regions of the first electrode 101 and the second electrode 102, the above-mentioned effect can be sufficiently achieved by assuming any position of the first electrode 101 and the second electrode 102 as the reflective region. Furthermore, the optical distance between the first electrode 101 and the light-emitting layer from which desired light is obtained can be strictly defined as the optical distance between the reflective region of the first electrode 101 and the light-emitting region of the light-emitting layer from which desired light is obtained. However, since it is difficult to precisely determine the reflective region of the first electrode 101 and the light-emitting region of the light-emitting layer from which desired light is obtained, the above-mentioned effect can be sufficiently achieved by assuming any position of the first electrode 101 as the reflective region and any position of the light-emitting layer from which desired light is obtained as the light-emitting region.

[0142] In the light-emitting device according to one embodiment of the present invention, at least one of the first electrode 101 and the second electrode 102 is a light-transmitting electrode (such as a transparent electrode or a semi-transmitting / semi-reflective electrode). When the light-transmitting electrode is a transparent electrode, the visible light transmittance of the transparent electrode is 40% or more. In addition, when the semi-transmitting / semi-reflective electrode is used, the visible light reflectance of the semi-transmitting / semi-reflective electrode is 20% or more and 80% or less, preferably 40% or more and 70% or less. Furthermore, these electrodes have a resistivity of 1×10 -2 It is preferable to set it to Ωcm or less.

[0143] In the above-described light-emitting device according to one embodiment of the present invention, when one of the first electrode 101 and the second electrode 102 is a reflective electrode (a reflective electrode), the reflectivity of the reflective electrode for visible light is set to 40% to 100%, preferably 70% to 100%. -2 It is preferable to set it to Ωcm or less.

[0144] <Hole injection layer> The hole injection layers (111, 111a, 111b) are layers that inject holes from the first electrode 101, which is an anode, and the charge generation layers (106, 106a, 106b) into the organic compound layers (103, 103a, 103b), and are layers that contain an organic acceptor material and a material with high hole injection properties.

[0145] An organic acceptor material is a material that can generate holes in an organic compound by causing charge separation between the organic acceptor material and another organic compound whose LUMO level and HOMO level are close to each other. Therefore, compounds having an electron-withdrawing group (a halogen group or a cyano group), such as quinodimethane derivatives, chloranil derivatives, and hexaazatriphenylene derivatives, can be used as the organic acceptor material. For example, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), 3,6-difluoro-2,5,7,7,8,8-hexacyanoquinodimethane, chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile, and the like can be used. Among organic acceptor materials, compounds such as HAT-CN, in which an electron-withdrawing group is bonded to a fused aromatic ring containing multiple heteroatoms, are particularly suitable because of their high acceptability and thermal stability. Radialene derivatives with electron-withdrawing groups (especially halogen groups such as fluoro groups or cyano groups) are also preferred because of their extremely high electron-accepting properties. Specific examples include α,α',α''-1,2,3-cyclopropanetriylidenetris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidenetris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], and α,α',α''-1,2,3-cyclopropanetriylidenetris[2,3,4,5,6-pentafluorobenzeneacetonitrile].

[0146] As a material with high hole injection properties, an oxide of a metal belonging to Groups 4 to 8 of the periodic table (e.g., transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide) can be used. Specific examples include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among these, molybdenum oxide is preferred because it is stable in air, has low hygroscopicity, and is easy to handle. In addition, diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviation: HATNA), 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2',3'-c]phenazine (abbreviation: HATNA-F6), perylene tetracarboxylic acid derivatives such as 3,4,9,10-perylene tetracarboxylic diimide (abbreviation: PTCDI), and 3,4,9,10-perylene tetracarboxylic-bis-benzimidazole (abbreviation: PTCBI), (C 60 -Ih)[5,6]fullerene (abbreviation: C 60 ), (C70-D5h)[5,6]fullerene (abbreviation: C 70Organic compounds such as copper phthalocyanine (abbreviated as CuPc), zinc phthalocyanine (abbreviated as ZnPc), cobalt phthalocyanine (abbreviated as CoPc), iron phthalocyanine (abbreviated as FePc), tin phthalocyanine (abbreviated as SnPc), tin oxide phthalocyanine (abbreviated as SnOPc), titanium oxide phthalocyanine (abbreviated as TiOPc), and vanadium oxide phthalocyanine (abbreviated as VOPc) can be used. Phthalocyanine-based metal complexes such as CuPc or ZnPc, or 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2',3'-c]phenazine are particularly preferred. Among these, CuPc and ZnPc are preferred due to their low cost and excellent properties. Furthermore, ZnPc has a small diffusion coefficient for silicon, which reduces the risk of metal diffusion into the semiconductor affecting its characteristics, making it particularly suitable for use in display devices that use silicon semiconductors.

[0147] In addition to the above materials, we also have low molecular weight compounds such as 4,4',4''-tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4',4''-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: MTDATA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), N,N'-bis[4-bis(3-methylphenyl)aminophenyl]-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: DNTPD), and 1,3,5-tris[N Aromatic amine compounds such as -(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), 3-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), and 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1) can be used.

[0148] In addition, polymeric compounds (oligomers, dendrimers, polymers, etc.) such as poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD) can be used. Alternatively, polymeric compounds with added acids, such as poly(3,4-ethylenedioxythiophene) / polystyrene sulfonic acid (abbreviation: PEDOT / PSS) and polyaniline / polystyrene sulfonic acid (PAni / PSS), can also be used.

[0149] Furthermore, a mixed material containing a hole transport material and the above-mentioned organic acceptor material (electron accepting material) can also be used as the material with high hole injection properties. In this case, electrons are extracted from the hole transport material by the organic acceptor material, generating holes in the hole injection layer 111, and the holes are injected into the light-emitting layer 113 via the hole transport layer 112. Note that the hole injection layer 111 may be formed as a single layer made of a mixed material containing the hole transport material and the organic acceptor material (electron accepting material), or may be formed by laminating the hole transport material and the organic acceptor material (electron accepting material) as separate layers.

[0150] As for hole transporting materials, the hole mobility at a square root of the electric field strength [V / cm] of 600 is 1×10 -6 cm 2 A substance having a hole mobility of 1 / Vs or more is preferred. Note that other substances can be used as long as they have a higher hole transporting property than an electron transporting property.

[0151] In addition, the hole transporting material is preferably a compound having a π-electron-rich heteroaromatic ring (for example, a carbazole derivative, a furan derivative, or a thiophene derivative), or an aromatic amine (an organic compound having an aromatic amine skeleton).

[0152] Examples of carbazole derivatives (organic compounds having a carbazole ring) include bicarbazole derivatives (for example, 3,3'-bicarbazole derivatives) and aromatic amines having a carbazolyl group.

[0153] Specific examples of bicarbazole derivatives (for example, 3,3'-bicarbazole derivatives) include 9,9'-diphenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCP), 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviation: BisBPCz), 9,9'-bis(biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviation: BismBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H-3,3'-bicarbazole (abbreviation: mBPCCBP), and 9-(2-naphthyl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: βNCCP).

[0154] Specific examples of aromatic amines having a carbazolyl group include 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), N-(biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazol-3-amine (abbreviation: PCBiF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PC BBiF), N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]bis(9,9-dimethyl-9H-fluoren-2-yl)amine (abbreviation: PCBFF), N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-4-amine, N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-(9,9-dimethyl-9H-fluoren-2-yl)-9,9-dimethyl-9H-fluorene-4- Amine, N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-diphenyl-9H-fluoren-2-amine, N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-diphenyl-9H-fluoren-4-amine, N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi(9H-fluorene)- 2-amine, N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi(9H-fluoren)-4-amine, N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-(1,1':3',1''-terphenyl-4-yl)-9,9-dimethyl-9H-fluoren-2-amine, N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-(1,1':4',1''-terphenyl-4-yl)-9,9-Dimethyl-9H-fluoren-2-amine, N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-(1,1':3',1''-terphenyl-4-yl)-9,9-dimethyl-9H-fluoren-4-amine, N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-(1,1':4',1''-terphenyl-4-yl)-9,9-dimethyl-9H-fluoren-4-amine, 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine N,N'-bis(9-phenylcarbazol-3-yl)-N,N'-diphenylbenzene-1,3-diamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), 4-phenyldiphenyl-(9-phenyl-9H-carbazol-3-yl)amine (abbreviation: PCA1BP), N,N'-bis(9-phenylcarbazol-3-yl)-N,N'-diphenylbenzene-1,3-diamine (abbreviation: PCA2B), N,N',N''-triphenyl-N,N',N''-tris(9-phenylcarbazol-3-yl)benzene-1,3,5-triamine (abbreviation: PCA3B), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), 3-[N-(9-phenyl) 3-[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), 3-[N-(1-naphthyl)-N-(9-phenylcarbazole-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1), 3-[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA1), 3,6-bis[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA2), 3,6-bis[N-(4-diphenylaminophenyl)-N-(1-naphthyl)amino]-9-phenylcarbazole (abbreviation: PCzTPN2), N-(9,9-spirobi[9H-fluoren]-2-yl)-N,9-diphenylcarbazol-3-amine (abbreviation: PCASF), N-(4-biphenyl)-4-(carbazol-9-yl)phenylaniline (abbreviated as YGA1BP), N,N'-bis[4-(carbazol-9-yl)phenyl]-N,N'-diphenyl-9,9-dimethylfluorene-2,7-diamine (abbreviated as YGA2F), 4,4',4''-tris(carbazol-9-yl)triphenylamine (abbreviated as TCTA), etc.

[0155] In addition to the above, examples of carbazole derivatives include 9-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]phenanthrene (abbreviation: PCPPn), 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 1,3,5-tris[4-(N-carbazolyl)phenyl] [4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 9-[3-(triphenylsilyl)phenyl]-3,9'-bi-9H-carbazole (abbreviation: PSiCzCz), 9'-phenyl-9'H-9,3':6',9''-tercarbazole (abbreviation: PSiCzGI), 3,9-bis(9-phenyl-9H-carbazol-3-yl)-9H-carbazole (abbreviation: PCCzPC), 9-(biphenyl-4-yl)-9'-phenyl-3,3'-bi-9H-carbazole carbazole (abbreviation: PCCzBP), 9-(3-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCmBP), 9-(4-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCBP), 9,9'-di-2-naphthyl-3,3'-9H,9'H-bicarbazole (abbreviation: BisβNCz), 9-(2-naphthyl)-9'-[1,1':4',1"-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1" -terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-5'-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':4',1"-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-(triphenylen-2-yl)-3,3'-9H,Examples include 9'H-bicarbazole, 9-phenyl-9'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviation: PCCzTp), 9,9'-bis(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(4-biphenyl)-9'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, and 9-(triphenylen-2-yl)-9'-[1,1':3',1"-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole.

[0156] Specific examples of furan derivatives (organic compounds having a furan ring) include 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II).

[0157] Specific examples of thiophene derivatives (organic compounds having a thiophene ring) include organic compounds having a thiophene ring, such as 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV).

[0158] Specific examples of aromatic amines include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB or α-NPD), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviation: TPD), N,N'-bis(9,9'-spirobi[9H-fluoren]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP ... N-(9,9-dimethyl-2-diphenylamino-9H-fluoren-7-yl)diphenylamine (abbreviation: DPNF), ...spirobi[9H-fluoren]-2-yl)phenylamine (abbreviation: mBPAFLP), N-(9,9-dimethyl-9H-fluoren-2-yl)-N-{9,9-dimethyl-2-[N'-phenyl-N'-(9,9-dimethyl-9H-fluoren-2-yl)amino]-9H-fluoren-7-yl}phenylamine (abbreviation: DFLADFL), N-(9,9-dimethyl-2-diphenylamino-9H-fluoren-7-yl)diphenylamine (abbreviation: DPNF), N-(9,9-spirobi[9H-fluoren]-2-yl) -N,N'N'-triphenyl-1,4-phenylenediamine (abbreviation: DPASF), N,N'-diphenyl-N,N'-bis(4-diphenylaminophenyl)spirobi[9H-fluorene]-2,7-diamine (abbreviation: DPA2SF), 4,4',4''-tris[N-(1-naphthyl)-N-phenylamino]triphenylamine (abbreviation: 1'-TNATA), 4,4',4''-tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4',4''-tris[N-(3-methylphenyl)-N-phenylamine] amino]triphenylamine (abbreviation: m-MTDATA), N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), DNTPD, 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-Bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4''-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2- d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4', 4''-Diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4''-( 7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-Diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl] 4'-[4'-(3-phenyl-9H-carbazol-9-yl)biphenyl-4-yl]-4''-phenyltriphenylamine (abbreviated as TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviated as αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviated as αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviated as YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazol-9-yl)furan N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N- Bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), N,N-bis(9,9-dimethyl-9H-fluorene-2- N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-1-amine, and the like are mentioned.

[0159] Other examples of hole-transporting materials that can be used include polymeric compounds (oligomers, dendrimers, polymers, etc.) such as poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD). Alternatively, polymeric compounds with added acids, such as poly(3,4-ethylenedioxythiophene) / polystyrenesulfonic acid (abbreviation: PEDOT / PSS) and polyaniline / polystyrenesulfonic acid (PAni / PSS), can also be used.

[0160] However, the hole transport material is not limited to the above, and one or more of various known materials can be used as the hole transport material. When the above hole transport material is used in the light-emitting layer, a compound in which some or all of the hydrogen atoms are deuterated can also be used. In this case, the energy transfer efficiency in the light-emitting layer can be improved and deterioration of the compound can be suppressed, thereby improving the reliability of the light-emitting device.

[0161] The hole injection layers (111, 111a, 111b) can be formed using various known film formation methods, for example, vacuum deposition.

[0162] <Hole transport layer> The hole transport layers (112, 112a, 112b) are layers that transport holes injected from the first electrode 101 by the hole injection layers (111, 111a, 111b) to the light-emitting layers (113, 113a, 113b). The hole transport layers (112, 112a, 112b) are layers that contain a hole transport material. Therefore, the hole transport layers (112, 112a, 112b) can use the same hole transport material that can be used for the hole injection layers (111, 111a, 111b).

[0163] In the light-emitting device of one embodiment of the present invention, the light-emitting layers (113, 113a, 113b) can be formed using the same organic compound as that used in the hole-transport layers (112, 112a, 112b). It is more preferable to use the same organic compound in the hole-transport layers (112, 112a, 112b) and the light-emitting layers (113, 113a, 113b) because holes can be efficiently transported from the hole-transport layers (112, 112a, 112b) to the light-emitting layers (113, 113a, 113b).

[0164] Electron blocking layer The electron blocking layer 116 is provided for the purpose of preventing electrons from passing through from the light-emitting layer 113 to the first electrode 101. A material having excellent hole-transporting properties, poor electron-transporting properties, and a high LUMO level is suitable for the electron blocking layer 116. Among the substances listed above that can be used as the material for the hole-transporting layer 112, it is preferable to form the layer using a material having a LUMO level higher than the LUMO level of the material (at least the host material) constituting the light-emitting layer, preferably 0.30 eV or more higher. Note that the electron blocking layer can also be regarded as part of the hole-transporting layer 112 because it transports holes.

[0165] <Light-emitting layer> The light-emitting layers (113, 113a, and 113b) have the structure described in Embodiment 1 and are layers containing light-emitting materials. Light-emitting materials that can be used for the light-emitting layers (113, 113a, and 113b) include substances that emit light of colors such as blue, purple, blue-purple, green, yellow-green, yellow, orange, and red. When multiple light-emitting layers are provided, different light-emitting materials can be used for each layer to emit different light colors (for example, white light emission can be achieved by combining complementary light-emitting colors). When multiple light-emitting layers are provided, each light-emitting layer can emit the same color. A stacked structure of multiple light-emitting layers emitting the same light color can sometimes be more reliable than a single-layer structure. Furthermore, a stacked structure in which each light-emitting layer contains different light-emitting materials may be used.

[0166] <Materials capable of converting singlet excitation energy into luminescence> Materials that can be used in the light-emitting layers (113, 113a, 113b) and have the function of converting singlet excitation energy into light emission include the following fluorescent substances (fluorescent substances). Examples include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives. Pyrene derivatives are particularly preferred because of their high light emission quantum yield. Specific examples of pyrene derivatives include N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-bis(dibenzofuran-2-yl)-N,N'-diphenylpyrene-1,6-diamine (abbreviation: 1,6FrAPrn), N,N'-bis(dibenzothiophen-2-yl)-N, N'-diphenylpyrene-1,6-diamine (abbreviation: 1,6ThAPrn), N,N'-(pyrene-1,6-diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-6-amine] (abbreviation: 1,6BnfAPrn), N,N'-(pyrene-1,6-diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-02), N,N'-(pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), and the like.

[0167] In addition, 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2,2'-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl-9-anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2BPy), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenyl-4,4'-stilbenediamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)phenyl N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), 4-(10-phenyl-9-anthryl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), 4-(10-phenyl-9-anthryl)-4'- (9-Phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), 4-[4-(10-phenyl-9-anthryl)phenyl]-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPBA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenyl) N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: 2PCAPPA), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), and the like can be used.

[0168] In addition, N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis(biphenyl-2-yl)-N-[ 4-(9H-carbazol-9-yl)phenyl]-N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracen-9-amine (abbreviation: DPhAPhA), Coumarin 545T, N,N'-diphenylquinacridone (abbreviation: DPQd), rubrene, 5,12-bis(biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyran-4-ylidene)propanedinit (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM2), N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhA FD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB),6-Bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJTM), 1,6BnfAPrn-0 3, N,N'-diphenyl-N,N'-bis(9-phenyl-9H-carbazol-2-yl)naphtho[2,3-b;6,7-b']bisbenzofuran-3,10-diamine (abbreviated as 3,10PCA2Nbf(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviated as 3,10FrA2Nbf(IV)-02), etc. In particular, pyrenediamine compounds such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03 can be used.

[0169] <Materials capable of converting triplet excitation energy into luminescence> Next, examples of materials that can be used for the light-emitting layer 113 and have a function of converting triplet excitation energy into light emission include substances that emit phosphorescence (phosphorescent light-emitting substances).

[0170] A phosphorescent material is a compound that exhibits phosphorescence but does not exhibit fluorescence at a temperature range from low temperatures (e.g., 77 K) to room temperature (i.e., 77 K to 313 K). The phosphorescent material preferably contains a metal element with a large spin-orbit interaction, such as an organometallic complex, a metal complex (platinum complex), or a rare-earth metal complex. Specifically, a transition metal element is preferred, and a platinum group element (ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), or platinum (Pt)) is particularly preferred. Among these, iridium is preferred because it can increase the transition probability associated with the direct transition between the singlet ground state and the triplet excited state.

[0171] Phosphorescent materials (450 nm to 570 nm: blue or green) Examples of phosphorescent materials that exhibit blue or green light and have an emission spectrum with a peak wavelength of 450 nm or more and 570 nm or less include the following materials.

[0172] For example, tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: [Ir(mpptz-dmp)3]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Mptz)3]), tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato]iridium(III) Organic iridium complexes containing a 4H-triazole ring, such as tris[3-(5-biphenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(iPr5btz)3]), tris[3-(5-biphenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(iPr5btz)3]), tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(Mptz1-mp)3]), tris(1-methyl Organic iridium complexes containing a 1H-triazole ring, such as fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpim)3]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III), and tris[1-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) ) (abbreviation: [Ir(dmpimpt-Me)3]), organic iridium complexes containing an imidazole ring, such as bis[2-(4',6'-difluorophenyl)pyridinato-N,C2']iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridinato-N,C2']iridium(III) picolinate (abbreviation: FIrpic), and bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinato-N,C2']iridium(III) picolinate (abbreviation: FIrpic). 2’}iridium(III) picolinate (abbreviation: [Ir(CF3ppy)2(pic)]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’Examples include organic iridium complexes with phenylpyridine derivatives having electron-withdrawing groups as ligands, such as iridium(III) acetylacetonate (abbreviated as FIr(acac)), and organic platinum complexes such as (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-(4-tert-butyl-2-pyridinyl-κN)carbazole-2,1-diyl-κC1)platinum(II) (abbreviated as PtON-TBBI).

[0173] Phosphorescent materials (495 nm to 590 nm: green or yellow) Examples of phosphorescent materials that exhibit green or yellow color and have an emission spectrum with a peak wavelength of 495 nm or more and 590 nm or less include the following materials.

[0174] For example, tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)3]), tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)3]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)2(acac)]), (acetylacetonato)bis(6-tert- (butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)2(acac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm)2(acac)]), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(mpmp organoiridinium(III) containing a pyrimidine ring, such as (acetylacetonato)bis{4,6-dimethyl-2-[6-(2,6-dimethylphenyl)-4-pyrimidinyl-κN3]phenyl-κC}iridium(III) (abbreviation: [Ir(dmppm-dmp)2(acac)]), (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2(acac)]). iridium complexes, organic iridium complexes with a pyrazine ring such as (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-Me)2(acac)]) and (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-iPr)2(acac)]), tris(2-phenylpyridinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(ppy)3]), bis(2-phenylpyridinato-N,C 2’) Iridium(III) acetylacetonate (abbreviation: [Ir(ppy)2(acac)]), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: [Ir(bzq)2(acac)]), tris(benzo[h]quinolinato)iridium(III) (abbreviation: [Ir(bzq)3]), tris(2-phenylquinolinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(pq)3]), bis(2-phenylquinolinato-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: [Ir(pq)2(acac)]), bis[2-(2-pyridinyl-κN)phenyl-κC][2-(4-phenyl-2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy)2(4dppy)]), bis[2-(2-pyridinyl-κN)phenyl-κC][2-(4-methyl-5-phenyl-2-pyridinyl -κN)phenyl-κC], [2-d3-methyl-8-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) (abbreviation: Ir(5mppy-d3)2(mbfpypy-d3)), {2-(methyl-d3)-8-[4-(1-methylethyl-1-d)-2-pyridinyl-κN]benzo furo[2,3-b]pyridin-7-yl-κC}bis{5-(methyl-d3)-2-[5-(methyl-d3)-2-pyridinyl-κN]phenyl-κC}iridium(III) (abbreviated as Ir(5mtpy-d6)2(mbfpypy-iPr-d4)), [2-d3-methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC] Organic iridium complexes containing a pyridine ring, such as [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy)2(mbfpypy-d3)), [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy)2(mdppy)), and bis(2,4-diphenyl-1,3-oxazolato-N,C 2’) Iridium(III) acetylacetonate (abbreviation: [Ir(dpo)2(acac)]), bis{2-[4'-(perfluorophenyl)phenyl]pyridinato-N,C 2’}Iridium(III) acetylacetonate (abbreviation: [Ir(p-PF-ph)2(acac)]), bis(2-phenylbenzothiazolato-N,C 2’ ) iridium(III) acetylacetonate (abbreviated as [Ir(bt)2(acac)]), as well as rare earth metal complexes such as tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviated as [Tb(acac)3(Phen)]).

[0175] Phosphorescent materials (570 nm to 750 nm: yellow or red) Examples of phosphorescent materials that exhibit yellow or red color and have an emission spectrum with a peak wavelength of 570 nm or more and 750 nm or less include the following materials.

[0176] For example, pyrimidinato]iridium(III) 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 (dipivaloylmethanato)bis[4,6-di(naphthalen-1-yl)pyrimidinato]iridium(III) (abbreviation: [Ir(d1npm)2(dpm)]). Organometallic complexes containing an imidine ring, (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 bis{4,6-dimethyl-2-[3-(3,5-dimethylphenyl)-5-phenyl-2-pyrazinyl-κN]phenyl-κC}(2,6-dimethyl-3,5-heptanedionato-κN). 2O,O')iridium(III) (abbreviation: [Ir(dmdppr-P)2(dibm)]), bis{4,6-dimethyl-2-[5-(4-cyano-2,6-dimethylphenyl)-3-(3,5-dimethylphenyl)-2-pyrazinyl-κN]phenyl-κC}(2,2,6,6-tetramethyl-3,5-heptanedionato-κ) 2 O,O')iridium(III) (abbreviation: [Ir(dmdppr-dmCP)2(dpm)]), bis{2-[5-(2,6-dimethylphenyl)-3-(3,5-dimethylphenyl)-2-pyrazinyl-κN]-4,6-dimethylphenyl-κC}(2,2',6,6'-tetramethyl-3,5-heptanedionato-κO,O')iridium(III) (abbreviation: [Ir(dmdppr-dmp)2(dpm)]), (acetylacetonato)bis(2-methyl-3-phenylquinoxalinato-N,C 2 ) Iridium(III) (abbreviation: [Ir(mpq)2(acac)]), (acetylacetonato)bis(2,3-diphenylquinoxalinato-N,C 2’ )iridium(III) (abbreviation: [Ir(dpq)2(acac)]), organometallic complexes with a pyrazine ring such as (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq)2(acac)]), tris(1-phenylisoquinolinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(piq)3]), bis(1-phenylisoquinolinato-N,C 2’ ) iridium(III) acetylacetonate (abbreviation: [Ir(piq)2(acac)]), and bis[4,6-dimethyl-2-(2-quinolinyl-κN)phenyl-κC](2,4-pentanedionato-κ 2Examples of such complexes include organometallic complexes with a pyridine ring, such as (O,O')iridium(III) (abbreviation: [Ir(dmpqn)2(acac)]), platinum complexes, such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrinplatinum(II) (abbreviation: [PtOEP]), and rare earth metal complexes, such as tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: [Eu(DBM)3(Phen)]), and tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: [Eu(TTA)3(Phen)]).

[0177] 《TADF material》 The following materials can be used as TADF materials. TADF materials are materials that have a small difference between the S1 level and the T1 level (preferably 0.20 eV or less), can upconvert a triplet excited state to a singlet excited state with a small amount of thermal energy (reverse intersystem crossing), and efficiently emit light (fluorescence) from the singlet excited state. Conditions for efficiently obtaining thermally activated delayed fluorescence include an energy difference between the triplet excited energy level and the singlet excited energy level of 0.00 eV or more and 0.20 eV or less, preferably 0.00 eV or more and 0.10 eV or less. Delayed fluorescence in TADF materials refers to light emission that has a spectrum similar to that of normal fluorescence but has a significantly long lifetime. Its lifetime is 1×10 -6 seconds or 1×10 -3 More than a second.

[0178] The TADF material can also be used as an electron transporting material, a hole transporting material, or a host material.

[0179] Examples of TADF materials include fullerene and its derivatives, acridine derivatives such as proflavine, eosin, etc. Also included are metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd). Examples of metal-containing porphyrins include protoporphyrin-tin fluoride complex (abbreviation: SnF2(Proto IX)), mesoporphyrin-tin fluoride complex (abbreviation: SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (abbreviation: SnF2(Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (abbreviation: SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complex (abbreviation: SnF2(OEP)), etioporphyrin-tin fluoride complex (abbreviation: SnF2(Etio I)), and octaethylporphyrin-platinum chloride complex (abbreviation: PtCl2OEP).

[0180] [ka]

[0181] Other examples include 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2-[4-(10H-phenoxy) 3-[4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN), bis[4-(9, 9-Dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthracen]-10'-one (abbreviation: ACRSA), 4-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)benzofuro[3,2-d]pyrimidine (abbreviation: 4PCCzBfpm), 4-[4-(9'-phenyl-3,3'- Heteroaromatic compounds having a π-electron rich heteroaromatic compound and a π-electron deficient heteroaromatic compound, such as 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), may also be used.

[0182] In addition, a substance in which a π-electron-rich heteroaromatic compound and a π-electron-deficient heteroaromatic compound are directly bonded is particularly preferable because the donor property of the π-electron-rich heteroaromatic compound and the acceptor property of the π-electron-deficient heteroaromatic compound are both strong, thereby reducing the energy difference between the singlet excited state and the triplet excited state. Furthermore, a TADF material (TADF100) in which the singlet excited state and the triplet excited state are in thermal equilibrium may also be used as the TADF material. Such TADF materials have a short emission lifetime (excitation lifetime), which can suppress efficiency decline in light-emitting devices in the high-brightness range.

[0183] [ka]

[0184] In addition to the above, examples of materials capable of converting triplet excitation energy into luminescence include nanostructures of transition metal compounds having a perovskite structure. Nanostructures of metal halide perovskites are particularly preferred. Nanoparticles and nanorods are preferred as such nanostructures.

[0185] In the light-emitting layers (113, 113a, 113b, 113c), one or more substances having an energy gap larger than the energy gap of the light-emitting material (guest material) may be selected and used as the organic compound (host material, etc.) used in combination with the above-mentioned light-emitting material (guest material).

[0186] <Fluorescent host material> When the light-emitting material used in the light-emitting layer (113, 113a, 113b, 113c) is a fluorescent light-emitting substance, it is preferable to use, as the organic compound (host material) to be combined, an organic compound having a high energy level in a singlet excited state and a low energy level in a triplet excited state, or an organic compound with a high fluorescence quantum yield. Therefore, as long as an organic compound satisfies these conditions, a hole-transporting material (described above) or an electron-transporting material (described below) shown in this embodiment can be used. Note that when the hole-transporting material is used in the light-emitting layer, a compound in which some or all of the hydrogen atoms are deuterated can also be used. In this case, the energy transfer efficiency in the light-emitting layer can be improved and deterioration of the compound can be suppressed, thereby improving the reliability of the light-emitting device.

[0187] Although some of the examples overlap with those described above, examples of the organic compound (host material) that can be preferably combined with the light-emitting material (fluorescent material) include condensed polycyclic aromatic compounds such as anthracene derivatives, tetracene derivatives, phenanthrene derivatives, pyrene derivatives, chrysene derivatives, and dibenzo[g,p]chrysene derivatives.

[0188] Specific examples of organic compounds (host materials) that are preferably used in combination with fluorescent materials include 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA), 3,6-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: DPCzPA), 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 9,10-diphenylanthracene (abbreviation: DPAnth), N,N ... N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviated as CzA1PA), 4-(10-phenyl-9-anthryl)triphenylamine (abbreviated as DPhPA), YGAPA, PCAPA, N,9-diphenyl-N-{4-[4-(10-phenyl-9-anthryl)phenyl]phenyl}-9H-carbazol-3-amine (abbreviated as PCAPBA), N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazol-3-amine (abbreviated as 2PCAPA) , 6,12-dimethoxy-5,11-diphenylchrysene, N,N,N',N',N'',N'',N''',N'''-octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl] Benzo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10-[4'-(9-phenyl-9H-fluoren-9-yl)biphenyl-4-yl]anthracene (abbreviation: FLPPA), 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviation: α,β-ADN), 2-(10-phenylanthracen-9-yl)dibenzofuran, 2-(10-phenyl-9-anthracenyl)benzo[b]naphtho[2,3-d]furan (abbreviated as Bnf(II)PhA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviated as αN-βNPAnth), 2,9-di(1-naphthyl)-10-phenylanthracene (abbreviated as 2αN-αNPhA), 9-(1-naphthyl)-10-[3-(1-naphthyl)phenyl]anthracene (abbreviation: αN-mαNPAnth), 9-(2-naphthyl)-10-[3-(1-naphthyl)phenyl]anthracene (abbreviation: βN-mαNPAnth), 9-(1-naphthyl)-10-[4-(1-naphthyl)phenyl]anthracene (abbreviation: αN-αNPAnth), 9-(2-naphthyl)-10-[4-(2-naphthyl)phenyl] Anthracene (abbreviation: βN-βNPAnth), 2-(1-naphthyl)-9-(2-naphthyl)-10-phenylanthracene (abbreviation: 2αN-βNPhA), 9-(2-naphthyl)-10-[3-(2-naphthyl)phenyl]anthracene (abbreviation: βN-mβNPAnth), 1-{4-[10-(biphenyl-4-yl)-9-anthracenyl]phenyl}-2-ethyl-1H-benzimidazole (abbreviation: EtB ImPBPhA), 9,9'-bianthryl (abbreviated as BANT), 9,9'-(stilbene-3,3'-diyl)diphenanthrene (abbreviated as DPNS), 9,9'-(stilbene-4,4'-diyl)diphenanthrene (abbreviated as DPNS2), 1,3,5-tri(1-pyrenyl)benzene (abbreviated as TPB3), 5,12-diphenyltetracene, 5,12-bis(biphenyl-2-yl)tetracene, etc.

[0189] <Phosphorescent host material> Furthermore, when the light-emitting material used in the light-emitting layers (113, 113a, 113b, 113c) is a phosphorescent material, an organic compound having a triplet excitation energy greater than the triplet excitation energy (energy difference between the ground state and the triplet excited state) of the light-emitting material can be selected as the organic compound (host material) to be combined. Note that when multiple organic compounds (for example, a first host material and a second host material (or assist material)) are used in combination with the light-emitting material to form an exciplex, it is preferable to use these multiple organic compounds in combination with the phosphorescent material.

[0190] With this configuration, it is possible to efficiently obtain light emission using ExTET (Exciplex-Triplet Energy Transfer), which is an energy transfer from an exciplex to a light-emitting material. As a combination of multiple organic compounds, it is preferable to use one that easily forms an exciplex, and it is particularly preferable to combine a compound that easily accepts holes (hole transport material) with a compound that easily accepts electrons (electron transport material).

[0191] Although some of the examples overlap with those described above, examples of the organic compound (host material, assist material) that can be preferably combined with the light-emitting material (phosphorescent light-emitting substance) include aromatic amines (organic compounds having an aromatic amine skeleton), carbazole derivatives (organic compounds having a carbazole ring), dibenzothiophene derivatives (organic compounds having a dibenzothiophene ring), dibenzofuran derivatives (organic compounds having a dibenzofuran ring), oxadiazole derivatives (organic compounds having an oxadiazole ring), triazole derivatives (organic compounds having a triazole ring), benzimidazole derivatives (benzo Examples of suitable organic compounds include organic compounds having an imidazole ring, quinoxaline derivatives (organic compounds having a quinoxaline ring), dibenzoquinoxaline derivatives (organic compounds having a dibenzoquinoxaline ring), pyrimidine derivatives (organic compounds having a pyrimidine ring), triazine derivatives (organic compounds having a triazine ring), pyridine derivatives (organic compounds having a pyridine ring), bipyridine derivatives (organic compounds having a bipyridine ring), phenanthroline derivatives (organic compounds having a phenanthroline ring), furodiazin derivatives (organic compounds having a furodiazin ring), zinc- and aluminum-based metal complexes, and the like.

[0192] Among the organic compounds, specific examples of the aromatic amine and carbazole derivative, which are organic compounds with high hole-transport properties, include the same as the specific examples of the hole-transport material described above, and any of these is preferable as the host material.

[0193] Specific examples of the dibenzothiophene derivatives and dibenzofuran derivatives, which are organic compounds with high hole transport properties among the above organic compounds, include 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II), DBT3P-II, 2,8-dipheny Examples of suitable host materials include 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), and 4-[3-(triphenylen-2-yl)phenyl]dibenzothiophene (abbreviation: mDBTPTp-II).

[0194] Other preferred host materials include metal complexes having oxazole- or thiazole-based ligands, such as bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO) and bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ).

[0195] Specific examples of the organic compounds having high electron transport properties, such as oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, quinazoline derivatives, and phenanthroline derivatives, among the above organic compounds, include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II) and organic compounds containing heteroaromatic rings with an azole ring, such as 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs), and compounds containing heteroaromatic rings with a phenanthroline ring, such as bathophenanthroline (abbreviation: Bphen), bathocuproine (abbreviation: BCP), 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), and 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P). Organic compounds, 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4-(3,6-diphenyl-9H-carbazol-9-yl)phenyl]dibenzo[f,and organic compounds containing a heteroaromatic ring having a dibenzoquinoxaline ring, such as 2-{4-[9,10-di(2-naphthyl)-2-anthryl]phenyl}-1-phenyl-1H-benzimidazole (abbreviation: ZADN), and 2-[4'-(9-phenyl-9H-carbazol-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), all of which are preferable as host materials. ,

[0196] Specific examples of the pyridine derivatives, diazine derivatives (including pyrimidine derivatives, pyrazine derivatives, and pyridazine derivatives), triazine derivatives, and furodiazine derivatives, which are organic compounds with high electron transport properties among the above organic compounds, include 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(dibenzothiophen-4-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), and 4,6-bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II). Pyrimidine (abbreviation: 4,6mCzP2Pm), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1 ,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), 9,9'-[pyrimidine-4,6-diylbis(biphenyl-3,3'-diyl)]bis(9H-carbazole) (abbreviation: 4,6mCzBP2Pm), 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 8-(biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2- d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 9-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 9-[3'-(dibenzothiophen-4-yl)biphenyl-4-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9pmDBtBPNfpr), 11-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]phenanthro[9',10':4,5]furo[2,3-b]pyrazine (abbreviation: 11mDBtBPPnfpr), 11-[3'-(dibenzothiophen-4-yl)biphenyl-4-yl]phenanthro[9',10':4,5]furo[2,3-b]pyrazine, 11-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]phenanthro[9',10':4,5]furo[2,3-b]pyrazine, 12-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)phenanthro[9',10':4,5]furo[2,3-b]pyrazine (abbreviation: 12PCCzPnfpr), 9-[3'-(9 -phenyl-9H-carbazol-3-yl)biphenyl-4-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviated as 9pmPCBPNfpr), 9-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviated as 9PCCzNfpr), 10-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviated as 10PCCzNfpr), 9-[3'-(6-phenylbenzo[b]naphtho [1,2-d]furan-8-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mBnfBPNfpr), 9-{3-[6-(9,9-dimethylfluoren-2-yl)dibenzothiophen-4-yl]phenyl}naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mFDBtPNfpr), 9-[3'-(6-phenyldibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr-02), 9-[3-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)phenyl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mPCCzPNfpr), 9-[3'-(2,8-diphenyldibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine, 11-[3'-(2,8-diphenyldibenzothiophen-4-yl)biphenyl-3-yl]phenanthro[9',10':4,5]furo[2,3-b]pyrazine, 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-[3'-(triphenylen-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mTpBPTzn), 2-(biphenyl-4-yl)-4-phenyl-6-(9, 9'-Spirobi[9H-fluoren]-2-yl)-1,3,5-triazine (abbreviation: BP-SFTzn), 2,6-bis(4-naphthalen-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]-9-furan Examples of suitable host materials include organic compounds containing heteroaromatic rings with diazine rings, such as phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-(biphenyl-3-yl)-4-phenyl-6-{8-[(1,1':4',1''-terphenyl)-4-yl]-1-dibenzofuranyl}-1,3,5-triazine (abbreviation: mBP-TPDBfTzn), 6-(biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), and 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm).

[0197] Furthermore, among the above organic compounds, specific examples of metal complexes, which are organic compounds with high electron-transporting properties, include zinc- or aluminum-based metal complexes such as tris(8-quinolinolato)aluminum(III) (abbreviation: Alq), tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), and bis(8-quinolinolato)zinc(II) (abbreviation: Znq), as well as metal complexes having a quinoline ring or a benzoquinoline ring, all of which are preferable as the host material.

[0198] Other preferred host materials include polymer compounds such as poly(2,5-pyridinediyl) (abbreviation: PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviation: PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviation: PF-BPy).

[0199] Furthermore, we have developed bipolar organic compounds with high hole-transporting and electron-transporting properties, such as 9-phenyl-9'-(4-phenyl-2-quinazolinyl)-3,3'-bi-9H-carbazole (abbreviation: PCCzQz), 2-[4'-(9-phenyl-9H-carbazol-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H, 7H-Indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazin-2-yl]-11,12-dihydro-12-(biphenyl-3-yl)indolo[2,3-a]carbazole (abbreviation: BP-mBPIcz(II)Tzn), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazin-2-yl]-11,12-dihydro-12-phenyl-indolo[2,3-a]carbazole (abbreviation: BP-Icz(II)Tzn), 7-[4-(9-phenyl-9H-carbazol-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: PC-cgDBCzQz), 3-{3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]phenyl}-9-phenyl-9H-carbazole (abbreviation: mPCPDBfTzn), 9,9'-[6-(biphenyl-4-yl)-2-phenyl-1,3,5-triazine-4,3''-diyl]bis(9H Organic compounds having a diazine ring or a triazine ring, such as 3-phenyl-9-[4-phenyl-6-(9-phenyl-3-dibenzofuranyl)-1,3,5-triazin-2-yl]-9H-carbazole (abbreviation: PDBf-PCzTzn), and 9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzothienyl]-2-phenyl-9H-carbazole (abbreviation: PCzDBtTzn), can also be used as the host material.

[0200] <Hole Blocking Layer> The hole-blocking layer 117 is provided for the purpose of preventing holes from passing through from the light-emitting layer 113 to the second electrode 102. A material having excellent electron-transporting properties, poor hole-transporting properties, and a low HOMO level is suitable for the hole-blocking layer 117. Among the materials that can be used as the material for the electron-transporting layer 114 described later, a material having a HOMO level lower than the HOMO level of the material (at least the host material) constituting the light-emitting layer, preferably lower by 0.30 eV or more, is preferably used for the hole-blocking layer 117. Note that the hole-blocking layer can also be regarded as part of the electron-transporting layer 114 because it transports electrons.

[0201] <Electron transport layer> The electron transport layers (114, 114a, 114b) are layers that transport electrons injected from the second electrode 102 and the charge generation layers (106, 106a, 106b) by the electron injection layers (115, 115a, 115b) described later to the light-emitting layers (113, 113a, 113b). Note that the heat resistance of the light-emitting device according to one embodiment of the present invention can be improved by the electron transport layer having a stacked structure. In addition, the material used for the electron transport layers (114, 114a, 114b) is a material having an electron mobility of 1×10 or more at a square root of an electric field strength [V / cm] of 600. -6 cm 2 A substance having an electron mobility of 1 / Vs or higher is preferred. Note that other substances can be used as long as they have a higher electron transporting property than hole transporting property. The electron transport layer (114, 114a, 114b) functions as a single layer, but may also have a stacked structure of two or more layers. Note that the above mixed materials have heat resistance, so that by performing a photolithography process on the electron transport layer using such a mixed material, the influence of a thermal process on the device characteristics can be suppressed.

[0202] 《Electron transport material》 The electron transport material that can be used for the electron transport layer (114, 114a, 114b) can be an organic compound with high electron transport properties, such as a heteroaromatic compound. A heteroaromatic compound is a cyclic compound containing at least two different elements in the ring. The ring structure can be a three-, four-, five-, or six-membered ring, with a five- or six-membered ring being particularly preferred. The element contained in the heteroaromatic compound is preferably one or more of nitrogen, oxygen, or sulfur in addition to carbon. Nitrogen-containing heteroaromatic compounds (nitrogen-containing heteroaromatic compounds) are particularly preferred, and electron transport materials such as nitrogen-containing heteroaromatic compounds or compounds containing the same and having a π-electron-deficient heteroaromatic ring are preferred.

[0203] The electron transport material may be a material different from the material used in the light-emitting layer. Not all of the excitons generated by carrier recombination in the light-emitting layer can contribute to light emission, and they may diffuse to layers adjacent to or located nearby the light-emitting layer. To avoid this phenomenon, it is preferable that the energy level (lowest singlet excitation level or lowest triplet excitation level) of the material used in the layer adjacent to or located nearby the light-emitting layer is higher than that of the material used in the light-emitting layer. Therefore, by using a material different from the material used in the light-emitting layer as the electron transport material, a highly efficient device can be obtained.

[0204] A heteroaromatic compound is an organic compound that contains at least one heteroaromatic ring.

[0205] The heteroaromatic ring has any one of a pyridine ring, a diazine ring, a triazine ring, an azole ring, an oxazole ring, a thiazole ring, etc. The heteroaromatic ring having a diazine ring includes a heteroaromatic ring having a pyrimidine ring, a pyrazine ring, a pyridazine ring, etc. The heteroaromatic ring having an azole ring includes a heteroaromatic ring having an imidazole ring, a triazole ring, or an oxadiazole ring.

[0206] The heteroaromatic ring also includes a fused heteroaromatic ring having a fused ring structure, such as a quinoline ring, a benzoquinoline ring, a quinoxaline ring, a dibenzoquinoxaline ring, a quinazoline ring, a benzoquinazoline ring, a dibenzoquinazoline ring, a phenanthroline ring, a phlodiazin ring, or a benzimidazole ring.

[0207] Examples of heteroaromatic compounds include heteroaromatic compounds containing one or more of nitrogen, oxygen, and sulfur in addition to carbon, and examples of heteroaromatic compounds having a five-membered ring structure include heteroaromatic compounds having an imidazole ring, heteroaromatic compounds having a triazole ring, heteroaromatic compounds having an oxazole ring, heteroaromatic compounds having an oxadiazole ring, heteroaromatic compounds having a thiazole ring, and heteroaromatic compounds having a benzimidazole ring.

[0208] Furthermore, among heteroaromatic compounds containing one or more of nitrogen, oxygen, and sulfur in addition to carbon, examples of heteroaromatic compounds having a six-membered ring structure include heteroaromatic compounds having a heteroaromatic ring such as a pyridine ring, a diazine ring (including a pyrimidine ring, a pyrazine ring, and a pyridazine ring), a triazine ring, and an azole ring.Heteroaromatic compounds having a structure in which pyridine rings are linked include heteroaromatic compounds having a bipyridine structure and heteroaromatic compounds having a terpyridine structure.

[0209] Furthermore, examples of heteroaromatic compounds having a fused ring structure partially containing the above-mentioned 6-membered ring structure include heteroaromatic compounds having a fused heteroaromatic ring such as a quinoline ring, a benzoquinoline ring, a quinoxaline ring, a dibenzoquinoxaline ring, a phenanthroline ring, a furodiazine ring (including a structure in which an aromatic ring is fused to the furan ring of a furodiazine ring), and a benzimidazole ring.

[0210] Specific examples of the heteroaromatic compound having a five-membered ring structure (such as an azole ring (including an imidazole ring, a triazole ring, and an oxadiazole ring), an oxazole ring, a thiazole ring, and a benzimidazole ring) include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 3-(4-biphenylyl)-4-phenyl 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenylyl)-1,2,4-triazole (abbreviation: p-EtTAZ), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs), and the like.

[0211] Specific examples of the heteroaromatic compound having a 6-membered ring structure (including heteroaromatic rings having a pyridine ring, a diazine ring, a triazine ring, or the like) include heteroaromatic compounds having a pyridine ring, such as 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy) and 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB); 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1 ,3,5-triazine (abbreviation: PCCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-[3'-(triphenylen-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine azine (abbreviation: mTpBPTzn), 2-(biphenyl-4-yl)-4-phenyl-6-(9,9'-spirobi[9H-fluoren]-2-yl)-1,3,5-triazine (abbreviation: BP-SFTzn), 2,6-bis(4-naphthalen-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-(biphenyl-3 heteroaromatic compounds containing heteroaromatic rings with a triazine ring, such as 2-{3-[3-(dibenzothiophen-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTzn), 4,6-bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm ...6-Bis[3-(dibenzothiophen-4-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 4,6mCzBP2Pm, 6-(biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 4-[3,5-bis(9H-carbazol-9-yl)phenyl] yl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 4-[3-(dibenzothiophen-4-yl)phenyl]-8-(naphthalen-2-yl)-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8βN-4mDBtPBfpm), 8BP-4mDBtPBfpm, 9mDBtBPNfpr, 9pmDBtBPNfpr, 3,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzofuro[2,3-b]pyrazine (abbreviation: 3, 8mDBtP2Bfpr), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviated as 4,8mDBtP2Bfpm), 8-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[3,2-d]pyrimidine (abbreviated as 8mDBtBPNfpm), 8-[(2,2'-binaphthalen)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[ and heteroaromatic compounds containing a heteroaromatic ring having a diazine (pyrimidine) ring, such as 8-(1,1':4',1"-terphenyl-3-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm) and 8-(1,1':4',1"-terphenyl-3-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm). The aromatic compounds containing a heteroaromatic ring include heteroaromatic compounds having a fused heteroaromatic ring.

[0212] Other examples include 2,2'-(pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6(P-Bqn)2Py), 2,2'-(2,2'-bipyridine-6,6'-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 6,6'(P-Bqn)2BPy), 2,2'-(pyridine-2,6-diyl)bis{4-[4-(2-naphthyl)phenyl]-6-phenylpyrimidine} (abbreviation: 2,6(NP-PPm)2Py), and 6-(biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mB and heteroaromatic compounds containing a heteroaromatic ring having a triazine ring, such as 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine (abbreviation: TmPPPyTz), 2,4,6-tris(2-pyridyl)-1,3,5-triazine (abbreviation: 2Py3Tz), and 2-[3-(2,6-dimethyl-3-pyridyl)-5-(9-phenanthryl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTzn).

[0213] Specific examples of the heteroaromatic compound having a fused ring structure partially containing a 6-membered ring structure (heteroaromatic compound having a fused ring structure) include bathophenanthroline (abbreviation: Bphen), bathocuproine (abbreviation: BCP), 2,9-di(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2'-(1,3-phenylene)bis(9-furan), phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), 2,2'-(pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6(P-Bqn)2Py), 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4-(3,6-diphenyl-9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPD and heteroaromatic compounds having a quinoxaline ring, such as 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as 7mDBTPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as 7mDBTPDBq-II), and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as 6mDBTPDBq-II), 2mpPCBPDBq, etc.

[0214] In addition to the heteroaromatic compounds described above, the electron transport layers (114, 114a, 114b) may also include the following metal complexes: metal complexes having a quinoline ring or a benzoquinoline ring, such as tris(8-quinolinolato)aluminum(III) (abbreviation: Alq3), Almq3, 8-quinolinolato-lithium (abbreviation: Liq), BeBq2, bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), and bis(8-quinolinolato)zinc(II) (abbreviation: Znq); and metal complexes having an oxazole ring or a thiazole ring, such as bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO) and bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ).

[0215] In addition, polymer compounds such as poly(2,5-pyridinediyl) (abbreviation: PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviation: PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviation: PF-BPy) can also be used as electron transport materials.

[0216] The electron transport layer (114, 114a, 114b) may not only be a single layer, but also have a structure in which two or more layers made of the above-mentioned substances are stacked.

[0217] <Electron injection layer> The electron injection layers (115, 115a, 115b) are layers containing a substance with high electron injection properties. The electron injection layers (115, 115a, 115b) are layers for increasing the efficiency of electron injection from the second electrode 102, and it is preferable to use a material for the second electrode 102 having a work function whose difference in LUMO level is small (0.50 eV or less) compared with the LUMO level of the material for the electron injection layers (115, 115a, 115b). Therefore, alkali metals, alkaline earth metals, or compounds thereof such as lithium, cesium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF), 8-quinolinolato-lithium (abbreviated as Liq), 2-(2-pyridyl)phenolatolithium (abbreviated as LiPP), 2-(2-pyridyl)-3-pyridinolatolithium (abbreviated as LiPPy), 4-phenyl-2-(2-pyridyl)phenolatolithium (abbreviated as LiPPP), lithium oxide (LiO), and cesium carbonate can be used for the electron injection layer 115. Rare earth metal compounds such as erbium fluoride (ErF) and ytterbium (Yb) can also be used. In addition, 1-(9,9'-spirobi[9H-fluoren]-2-yl)-1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (abbreviation: 2hppSF), 1,1'-(9,9'-spirobi[9H-fluoren]-2,7-diyl)bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) Compounds having a 1,3,4,6,7,8-tetrahydro-2H-pyrimido[1,2-a]pyrimidine skeleton, such as 1,1'-pyridine-2,6-diyl-bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) (abbreviation: 2,7hpp2SF) and 1,1'-pyridine-2,6-diyl-bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) (abbreviation: hpp2Py), can also be used. The electron injection layers (115, 115a, 115b) may be formed by mixing a plurality of the above materials or by stacking a plurality of the above materials. The electron injection layers (115, 115a, 115b) may also be formed by using an electride. Examples of electrides include a substance in which a mixed oxide of calcium and aluminum is doped with a high concentration of electrons.The above-described materials constituting the electron transport layers (114, 114a, 114b) can also be used.

[0218] The electron injection layer (115, 115a, 115b) may also be made of a mixed material containing an organic compound and an electron donor (donor). Such a mixed material has excellent electron injection and electron transport properties because electrons are generated in the organic compound by the electron donor. In this case, the organic compound is preferably a material that is excellent at transporting the generated electrons. Specifically, the electron transport materials (metal complexes, heteroaromatic compounds, etc.) used in the electron transport layer (114, 114a, 114b) described above can be used. The electron donor may be any substance that exhibits electron donating properties to the organic compound. Specifically, alkali metals, alkaline earth metals, and rare earth metals are preferred, such as lithium, cesium, magnesium, calcium, erbium, and ytterbium. Alkali metal oxides and alkaline earth metal oxides are preferred, such as lithium oxide, calcium oxide, and barium oxide. Lewis bases such as magnesium oxide can also be used. Organic compounds such as tetrathiafulvalene (TTF) can also be used. Furthermore, a plurality of these materials may be laminated.

[0219] Alternatively, the electron injection layer (115, 115a, 115b) may be made of a mixed material containing an organic compound and a metal. The organic compound used here preferably has a LUMO level of -3.60 eV or more and -2.30 eV or less. A material having an unshared electron pair is also preferred.

[0220] Therefore, the organic compound used in the mixed material may be a mixed material obtained by mixing a heteroaromatic compound with a metal, as described above as being usable in the electron transport layer. Preferred heteroaromatic compounds include those having a five-membered ring structure (such as an imidazole ring, a triazole ring, an oxazole ring, an oxadiazole ring, a thiazole ring, or a benzimidazole ring), a six-membered ring structure (such as a pyridine ring, a diazine ring (including a pyrimidine ring, a pyrazine ring, or a pyridazine ring), a triazine ring, a bipyridine ring, or a terpyridine ring), or a fused ring structure partially including a six-membered ring structure (such as a quinoline ring, a benzoquinoline ring, a quinoxaline ring, a dibenzoquinoxaline ring, or a phenanthroline ring). Specific materials are described above, so further explanation is omitted here.

[0221] As the metal used in the mixed material, it is preferable to use a transition metal belonging to Group 5, 7, 9 or 11 in the periodic table and a material belonging to Group 13, such as Ag, Cu, Al or In. In this case, the organic compound forms a half-occupied molecular orbital (SOMO) with the transition metal.

[0222] For example, when light obtained from the light-emitting layer 113b is to be amplified, the optical distance between the second electrode 102 and the light-emitting layer 113b is preferably set to be less than ¼ of the wavelength λ of the light emitted by the light-emitting layer 113b. In this case, the optical distance can be adjusted by changing the film thickness of the electron-transporting layer 114b or the electron-injecting layer 115b.

[0223] Furthermore, as in the light-emitting device shown in Figure 4(E), by providing a charge generation layer 106 between two organic compound layers (103a, 103b), a structure in which multiple organic compound layers are stacked between a pair of electrodes (also called a tandem structure) can be formed.

[0224] <Charge Generation Layer> The charge generation layer 106 has a function of injecting electrons into one organic compound layer (103a or 103b) and injecting holes into the other organic compound layer (103b or 103a) when a voltage is applied between the first electrode (anode) 101 and the second electrode (cathode) 102. The charge generation layer 106 may be a structure in which an electron acceptor is added to a hole transporting material (also referred to as a P-type layer) or a structure in which an electron donor is added to an electron transporting material (also referred to as an electron injection buffer layer). Alternatively, both of these structures may be stacked. Furthermore, an electron relay layer may be provided between the P-type layer and the electron injection buffer layer. Forming the charge generation layer 106 having a P-type layer and an electron injection buffer layer can suppress an increase in driving voltage when organic compound layers are stacked.

[0225] When the charge generation layer 106 has a structure in which an electron acceptor is added to a hole-transporting material that is an organic compound (a P-type layer), the material described in this embodiment can be used as the hole-transporting material. Examples of the electron acceptor include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ) and chloranil. Examples of the electron acceptor include oxides of metals that belong to Groups 4 to 8 of the periodic table. Specific examples include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide. The acceptor materials described above may also be used. Materials for the P-type layer may be mixed together to form a mixed film, or single films containing each material may be stacked.

[0226] When the charge generation layer 106 has a structure in which an electron donor is added to an electron transporting material (electron injection buffer layer), the material described in this embodiment can be used as the electron transporting material. The electron donor can be an alkali metal, an alkaline earth metal, a rare earth metal, or a metal belonging to Groups 2 and 13 of the periodic table, or an oxide or carbonate thereof. Specifically, lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium oxide (LiO), cesium carbonate, or the like is preferably used. An alkali metal compound such as Liq can also be used. An organic compound such as tetrathianaphthacene can also be used as the electron donor. Alternatively, organic compounds having a 1,3,4,6,7,8-tetrahydro-2H-pyrimido[1,2-a]pyrimidine skeleton, such as 2hppSF, 2,7hpp2SF, and hpp2Py, may be used as electron donors. When using these organic compounds as electron donors, it is preferable to combine them with electron transport materials containing a heteroaromatic ring having a phenanthroline ring, such as bathophenanthroline (abbreviated as Bphen), bathocuproine (abbreviated as BCP), 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBphen), or 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviated as mPPhen2P), because this reduces the driving voltage of light-emitting devices.

[0227] When an electron relay layer is provided between the P-type layer and the electron injection buffer layer in the charge generation layer 106, the electron relay layer contains at least a substance having electron transport properties and has the function of preventing interaction between the electron injection buffer layer and the P-type layer and smoothly transferring electrons. The LUMO level of the substance having electron transport properties contained in the electron relay layer is preferably between the LUMO level of the acceptor substance in the P-type layer and the LUMO level of the substance having electron transport properties contained in the electron transport layer in contact with the charge generation layer 106. The specific energy level of the LUMO level of the substance having electron transport properties used in the electron relay layer is −5.00 eV or higher, preferably −5.00 eV or higher and −3.00 eV or lower. Note that the substance having electron transport properties used in the electron relay layer is preferably a phthalocyanine-based material or a metal complex having a metal-oxygen bond and an aromatic ligand.

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

[0229] Although FIG. 4E shows a structure in which two organic compound layers 103 are stacked, a stack structure of three or more organic compound layers may be used by providing a charge generation layer between different organic compound layers.

[0230] <Cap layer> Although not shown in FIGS. 4A to 4F, a capping layer may be provided on the second electrode 102 of the light-emitting device. For example, a material with a high refractive index can be used for the capping layer. By providing the capping layer on the second electrode 102, the extraction efficiency of light emitted from the second electrode 102 can be improved.

[0231] Specific examples of materials that can be used for the cap layer include 5,5'-diphenyl-2,2'-di-5H-[1]benzothieno[3,2-c]carbazole (abbreviation: BisBTc) and 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II).

[0232] <substrate> The light-emitting device described in this embodiment mode can be formed on various substrates. Note that the type of substrate is not limited to a specific one. Examples of the substrate include a semiconductor substrate (for example, a single crystal substrate or a silicon substrate), an SOI substrate, a glass substrate, a quartz substrate, a plastic substrate, a metal substrate, a stainless steel substrate, a substrate having stainless steel foil, a tungsten substrate, a substrate having tungsten foil, a flexible substrate, a laminated film, paper containing a fibrous material, or a base film.

[0233] Examples of glass substrates include barium borosilicate glass, aluminoborosilicate glass, soda lime glass, etc. Examples of flexible substrates, laminated films, base films, etc. include plastics such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyethersulfone (PES), synthetic resins such as acrylic resins, polypropylene, polyester, polyvinyl fluoride, polyvinyl chloride, polyamide, polyimide, aramid, epoxy resins, inorganic vapor deposition films, and papers.

[0234] The light-emitting device described in this embodiment can be fabricated by a gas-phase method such as vapor deposition, a spin coating method, or a liquid-phase method such as an inkjet method. When a vapor deposition method is used, a physical vapor deposition (PVD) method such as sputtering, ion plating, ion beam deposition, molecular beam deposition, or vacuum deposition, or a chemical vapor deposition (CVD) method can be used. In particular, layers having various functions (hole injection layer 111, hole transport layer 112, light-emitting layer 113, electron transport layer 114, and electron injection layer 115) included in the organic compound layer of the light-emitting device can be formed by a vapor deposition method (vacuum deposition, etc.), a coating method (dip coating, die coating, bar coating, spin coating, spray coating, etc.), a printing method (inkjet printing, screen (stencil printing), offset (lithographic printing), flexography (relief printing), gravure printing, microcontact printing, etc.), or the like.

[0235] When applying the above-mentioned coating method, printing method, or other film formation method, it is possible to use high molecular weight compounds (oligomers, dendrimers, polymers, etc.), medium molecular weight compounds (compounds in the intermediate range between low molecular weight and high molecular weight: molecular weight of 400 to 4000), inorganic compounds (quantum dot materials, etc.), etc. As quantum dot materials, colloidal quantum dot materials, alloy-type quantum dot materials, core-shell type quantum dot materials, core-type quantum dot materials, etc. can be used.

[0236] The layers constituting the organic compound layer 103 of the light-emitting device shown in this embodiment (hole injection layer 111, hole transport layer 112, light-emitting layer 113, electron transport layer 114, and electron injection layer 115) are not limited to the materials shown in this embodiment, and other materials can be used in combination as long as they can fulfill the functions of each layer.

[0237] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0238] (Embodiment 3) In this embodiment, a light-emitting device 1000 according to one embodiment of the present invention will be described in detail. Note that in this specification and the like, a light-emitting device may be referred to as a display device.

[0239] 5A, the light emitting device 1000 includes a pixel portion 177 in which a plurality of pixels 178 are arranged in a matrix. The pixel 178 includes a sub-pixel 110R, a sub-pixel 110G, and a sub-pixel 110B.

[0240] In this specification and the like, when describing matters common to, for example, the subpixels 110R, 110G, and 110B, they may be referred to as the subpixels 110. When describing matters common to other components distinguished by alphabets, they may also be described using symbols without the alphabets.

[0241] The sub-pixel 110R emits red light, the sub-pixel 110G emits green light, and the sub-pixel 110B emits blue light. This allows an image to be displayed in the pixel unit 177. In this embodiment, sub-pixels of three colors, red (R), green (G), and blue (B), are described as an example, but combinations of sub-pixels of other colors may also be used. The number of sub-pixels is not limited to three, and may be four or more. Examples of four sub-pixels include sub-pixels of four colors: R, G, B, and white (W); sub-pixels of four colors: R, G, B, and yellow (Y); and sub-pixels of R, G, B, and infrared (IR).

[0242] In this specification, the row direction may be referred to as the X direction, and the column direction may be referred to as the Y direction. The X direction and the Y direction intersect, for example, perpendicularly.

[0243] 5A shows an example in which sub-pixels of different colors are arranged side by side in the X direction, and sub-pixels of the same color are arranged side by side in the Y direction. Note that sub-pixels of different colors may also be arranged side by side in the Y direction, and sub-pixels of the same color may also be arranged side by side in the X direction.

[0244] A connection portion 140 may be provided outside the pixel portion 177, and a region 141 may be provided. The region 141 is provided between the pixel portion 177 and the connection portion 140. The region 141 is provided with an organic compound layer 103. Furthermore, the connection portion 140 is provided with a conductive layer 151C.

[0245] 5A shows an example in which the region 141 and the connection portion 140 are located on the right side of the pixel portion 177, but the positions of the region 141 and the connection portion 140 are not particularly limited. The region 141 and the connection portion 140 may be singular or plural.

[0246] Fig. 5(B) is an example of a cross-sectional view taken along dashed line A1-A2 in Fig. 5(A). As shown in Fig. 5(B), the light-emitting device 1000 includes an insulating layer 171, a conductive layer 172 on the insulating layer 171, an insulating layer 173 on the insulating layer 171 and on the conductive layer 172, an insulating layer 174 on the insulating layer 173, and an insulating layer 175 on the insulating layer 174. The insulating layer 171 is provided on a substrate (not shown). The insulating layer 175, the insulating layer 174, and the insulating layer 173 have openings that reach the conductive layer 172, and a plug 176 is provided to fill the opening.

[0247] In the pixel section 177, the light-emitting device 130 is provided on the insulating layer 175 and the plug 176. A protective layer 135 is provided to cover the light-emitting device 130. The substrate 120 is bonded to the protective layer 135 by a resin layer 122. Preferably, an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 are provided between adjacent light-emitting devices 130.

[0248] 5B shows multiple cross sections of the inorganic insulating layer 125 and the insulating layer 127, it is preferable that the inorganic insulating layer 125 and the insulating layer 127 are connected to one another when the light-emitting device 1000 is viewed from above. That is, it is preferable that the inorganic insulating layer 125 and the insulating layer 127 are insulating layers having openings above the first electrodes.

[0249] 5(B) shows light emitting device 130R, light emitting device 130G, and light emitting device 130B. Light emitting device 130R, light emitting device 130G, and light emitting device 130B emit light of different colors. For example, light emitting device 130R can emit red light, light emitting device 130G can emit green light, and light emitting device 130B can emit blue light. Light emitting device 130R, light emitting device 130G, or light emitting device 130B may also emit other visible light or infrared light.

[0250] The display device of one embodiment of the present invention can be, for example, a top-emission type that emits light in the direction opposite to the substrate on which the light-emitting device is formed. Note that the display device of one embodiment of the present invention may also be a bottom-emission type.

[0251] Examples of the light-emitting material included in the light-emitting device 130 include organic compounds such as fluorescent substances, phosphorescent substances, and thermally activated delayed fluorescence (TADF) materials, or organometallic complexes of one embodiment of the present invention. Furthermore, the light-emitting material may be an inorganic compound such as quantum dots.

[0252] The light-emitting device 130R has the configuration described in Embodiments 1 and 2. It includes a first electrode (pixel electrode) composed of a conductive layer 151R and a conductive layer 152R, an organic compound layer 103R on the first electrode, a common layer 104 on the organic compound layer 103R, and a second electrode (common electrode) 102 on the common layer 104. The common layer 104 may or may not be provided, but is preferably provided because it can reduce damage to the organic compound layer 103R during processing. When the common layer 104 is provided, it is preferably an electron injection layer. When the common layer 104 is not provided, the organic compound layer 103R corresponds to the organic compound layer 103 in Embodiments 1 and 2. When the common layer 104 is provided, the stacked structure of the organic compound layer 103R and the common layer 104 corresponds to the organic compound layer 103 in Embodiments 1 and 2.

[0253] The light-emitting device 130G has the configuration described in Embodiments 1 and 2. It includes a first electrode (pixel electrode) including a conductive layer 151G and a conductive layer 152G, an organic compound layer 103G on the first electrode, a common layer 104 on the organic compound layer 103G, and a second electrode (common electrode) 102 on the common layer 104. The common layer 104 may or may not be provided, but is preferably provided because it can reduce damage to the organic compound layer 103G during processing. When the common layer 104 is not provided, the organic compound layer 103G corresponds to the organic compound layer 103 in Embodiments 1 and 2. When the common layer 104 is provided, the stacked structure of the organic compound layer 103G and the common layer 104 corresponds to the organic compound layer 103 in Embodiments 1 and 2.

[0254] The light-emitting device 130B has the configuration described in Embodiments 1 and 2. It includes a first electrode (pixel electrode) including a conductive layer 151B and a conductive layer 152B, an organic compound layer 103B on the first electrode, a common layer 104 on the organic compound layer 103B, and a second electrode (common electrode) 102 on the common layer 104. The common layer 104 may or may not be provided, but is preferably provided because it reduces damage to the organic compound layer 103B during processing. When the common layer 104 is not provided, the organic compound layer 103B corresponds to the organic compound layer 103 in Embodiments 1 and 2. When the common layer 104 is provided, the stacked structure of the organic compound layer 103B and the common layer 104 corresponds to the organic compound layer 103 in Embodiments 1 and 2.

[0255] One of the pixel electrode and the common electrode of the light-emitting device functions as an anode and the other functions as a cathode. In the following description, unless otherwise specified, the pixel electrode functions as an anode and the common electrode functions as a cathode.

[0256] The organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B are independent island-shaped layers for each light-emitting device or for each emitted color. By providing the organic compound layer 103 in island-shaped layers for each light-emitting device 130, leakage current between adjacent light-emitting devices 130 can be suppressed even in a high-resolution light-emitting device. This prevents crosstalk and realizes a light-emitting device with extremely high contrast. In particular, a light-emitting device with high current efficiency at low luminance can be realized.

[0257] The island-shaped organic compound layer 103 is formed by depositing an EL film and processing the EL film using a lithography method.

[0258] In the light-emitting device of one embodiment of the present invention, the first electrode (pixel electrode) of the light-emitting device preferably has a stacked structure. For example, in the example shown in FIG. 5B, the first electrode of the light-emitting device 130 has a stacked structure of a conductive layer 151 and a conductive layer 152. For example, when the light-emitting device 1000 is a top-emission type and the pixel electrode of the light-emitting device 130 functions as an anode, the conductive layer 151 preferably has high reflectivity for visible light, and the conductive layer 152 preferably has transparency to visible light and a high work function. When the light-emitting device 1000 is a top-emission type, the higher the reflectivity of the pixel electrode for visible light, the higher the extraction efficiency of light emitted from the organic compound layer 103. When the pixel electrode functions as an anode, the higher the work function of the pixel electrode, the easier it is to inject holes into the organic compound layer 103. As described above, by forming the pixel electrode of the light-emitting device 130 into a laminated structure of the conductive layer 151 having a high reflectivity for visible light and the conductive layer 152 having a high work function, the light-emitting device 130 can be made into a light-emitting device with high light extraction efficiency and low driving voltage.

[0259] When the conductive layer 151 is a layer having high reflectivity to visible light, the reflectivity of the conductive layer 151 to visible light is, for example, preferably 40% to 100%, more preferably 70% to 100%. When the conductive layer 152 is an electrode having transparency to visible light, the transmittance to visible light is preferably, for example, 40% or more.

[0260] Here, when the pixel electrode has a laminated structure made up of multiple layers, the pixel electrode may be altered due to, for example, a reaction between the multiple layers. For example, when a film formed after forming the pixel electrode is removed by a wet etching method, galvanic corrosion may occur when a chemical solution comes into contact with the pixel electrode.

[0261] Therefore, in the light-emitting device 1000 of this embodiment, it is preferable to form an insulating layer 156 on the side surfaces of the conductive layer 151 and the conductive layer 152, as shown in FIG. 5(B). This prevents a chemical solution from coming into contact with the conductive layer 151, even when a film formed after forming a pixel electrode having the conductive layer 151 and the conductive layer 152 is removed by wet etching, for example. This prevents, for example, galvanic corrosion from occurring in the pixel electrode. Therefore, the light-emitting device 1000 can be manufactured by a method with a high yield, and therefore can be a low-cost light-emitting device. Furthermore, since defects in the light-emitting device 1000 can be prevented, the light-emitting device 1000 can be a highly reliable light-emitting device.

[0262] For example, a metal material can be used for the conductive layer 151. Specifically, metals such as aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd), etc., and alloys containing appropriate combinations of these metals can also be used.

[0263] The conductive layer 152 can be formed using an oxide containing one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon. For example, it is preferable to use a conductive oxide containing one or more of indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide containing gallium, titanium oxide, indium zinc oxide containing gallium, indium zinc oxide containing aluminum, indium tin oxide containing silicon, and indium zinc oxide containing silicon. In particular, indium tin oxide containing silicon has a large work function, for example, a work function of 4.0 eV or more, and therefore can be suitably used for the conductive layer 152.

[0264] The conductive layer 151 may have a stacked structure of multiple layers containing different materials, and the conductive layer 152 may have a stacked structure of multiple layers containing different materials. In this case, the conductive layer 151 may include a layer containing a material that can be used for the conductive layer 152, such as a conductive oxide, or the conductive layer 152 may include a layer containing a material that can be used for the conductive layer 151, such as a metal material. For example, when the conductive layer 151 has a stacked structure of two or more layers, a layer in contact with the conductive layer 152 can be a layer containing a material that can be used for the conductive layer 152.

[0265] Note that the conductive layer 151 may have a tapered end. Specifically, when the conductive layer 151 has a tapered end with a taper angle of less than 90°, coverage of a structure provided along the side surface of the insulating layer 156 can be improved.

[0266] 6A shows a case where the conductive layer 151 has a stacked structure of multiple layers containing different materials. As shown in FIG. 6A, the conductive layer 151 has a structure including a conductive layer 151a, a conductive layer 151b on the conductive layer 151a, and a conductive layer 151c on the conductive layer 151b. That is, the conductive layer 151 shown in FIG. 6A has a three-layer stacked structure. In this way, when the conductive layer 151 has a stacked structure of multiple layers, the reflectivity of at least one of the layers constituting the conductive layer 151 to visible light should be higher than the reflectivity of the conductive layer 152 to visible light.

[0267] 6A, the conductive layer 151b is sandwiched between the conductive layer 151a and the conductive layer 151c. The conductive layer 151a and the conductive layer 151c are preferably made of a material that is less likely to change in quality than the conductive layer 151b. For example, the conductive layer 151a can be made of a material that is less likely to migrate due to contact with the insulating layer 175 than the conductive layer 151b. The conductive layer 151c can be made of a material that is less likely to oxidize than the conductive layer 151b and has an oxide with lower electrical resistivity than the oxide of the material used for the conductive layer 151b.

[0268] As described above, by sandwiching the conductive layer 151b between the conductive layer 151a and the conductive layer 151c, the range of materials that can be selected for the conductive layer 151b can be expanded. This allows the conductive layer 151b to have a higher reflectivity for visible light than at least one of the conductive layer 151a and the conductive layer 151c. For example, aluminum can be used for the conductive layer 151b. An alloy containing aluminum may also be used for the conductive layer 151b. Furthermore, titanium, which has a lower reflectivity for visible light than aluminum but is less likely to migrate than aluminum even when in contact with the insulating layer 175, can be used for the conductive layer 151a. Furthermore, titanium, which has a lower reflectivity for visible light than aluminum but is less likely to oxidize than aluminum and has an oxide with lower electrical resistivity than aluminum oxide, can be used for the conductive layer 151c.

[0269] Alternatively, the conductive layer 151c may be made of silver or a silver-containing alloy. Silver has a higher visible light reflectance than titanium. Furthermore, silver is less susceptible to oxidation than aluminum, and the electrical resistivity of silver oxide is lower than that of aluminum oxide. Therefore, using silver or a silver-containing alloy for the conductive layer 151c can favorably increase the visible light reflectance of the conductive layer 151 while suppressing an increase in the electrical resistance of the pixel electrode due to oxidation of the conductive layer 151b. An example of an alloy containing silver is an alloy of silver, palladium, and copper (Ag-Pd-Cu, also referred to as APC). Using silver or a silver-containing alloy for the conductive layer 151c and aluminum for the conductive layer 151b can increase the visible light reflectance of the conductive layer 151c compared to the visible light reflectance of the conductive layer 151b. The conductive layer 151b may be made of silver or a silver-containing alloy. Alternatively, the conductive layer 151a may be made of silver or an alloy containing silver.

[0270] On the other hand, a film using titanium has better etching processability than a film using silver. Therefore, by using titanium for the conductive layer 151c, the conductive layer 151c can be easily formed. Note that a film using aluminum also has better etching processability than a film using silver.

[0271] As described above, the characteristics of the light-emitting device can be improved by forming the conductive layer 151 with a stacked structure of multiple layers. For example, the light-emitting device 1000 can have high light extraction efficiency and high reliability.

[0272] Here, when a microcavity structure is applied to the light-emitting device 130, the light extraction efficiency of the light-emitting device 1000 can be suitably improved by using silver or an alloy containing silver, which is a material with high reflectivity for visible light, as the conductive layer 151c.

[0273] As described above, the side surfaces of the conductive layer 151 preferably have a tapered shape. Specifically, the side surfaces of the conductive layer 151 preferably have a tapered shape with a taper angle of less than 90°. For example, in the conductive layer 151 having the structure shown in FIG. 6A, at least one of the side surfaces of the conductive layer 151a, the conductive layer 151b, and the conductive layer 151c preferably has a tapered shape.

[0274] The conductive layer 151 shown in FIG. 6A can be formed by lithography. Specifically, first, a conductive film to be the conductive layer 151a, a conductive film to be the conductive layer 151b, and a conductive film to be the conductive layer 151c are formed in this order. Next, a resist mask is formed on the conductive film to be the conductive layer 151c. After that, the conductive film in a region that does not overlap with the resist mask is removed by, for example, an etching method. Here, compared to when the conductive layer 151 is formed so that the side surfaces are not tapered, that is, so that the side surfaces are vertical, the conductive film can be formed with a tapered shape by processing the conductive film under conditions that make it easy for the resist mask to recede (shrink).

[0275] Here, if the conductive film is processed under conditions that make it easy for the resist mask to recede (shrink), the conductive film may be easily processed in the horizontal direction, which may result in higher isotropy of etching than when the conductive layer 151 is formed so that the side surfaces are vertical.

[0276] Furthermore, when the conductive layer 151 has a laminated structure of multiple layers made of different materials, the layers may differ in ease of processing in the horizontal direction. For example, the conductive layer 151a, the conductive layer 151b, and the conductive layer 151c may differ in ease of processing in the horizontal direction.

[0277] In this case, after processing the conductive film, the side surface of conductive layer 151b may be located inside the side surfaces of conductive layers 151a and 151c, forming a protruding portion, which may reduce the coverage of conductive layer 152 with respect to conductive layer 151, and may cause discontinuities in conductive layer 152.

[0278] Therefore, it is preferable to provide an insulating layer 156 as shown in Fig. 6A. Fig. 6A shows an example in which the insulating layer 156 is provided over the conductive layer 151a so as to have a region overlapping with the side surface of the conductive layer 151b. This can prevent the conductive layer 152 from being broken or thinned due to the protrusion, thereby suppressing poor connection or an increase in driving voltage.

[0279] 6A illustrates a structure in which the side surfaces of the conductive layer 151b are entirely covered with the insulating layer 156, but the side surfaces of the conductive layer 151b may not be partially covered with the insulating layer 156. Similarly, in pixel electrodes having structures to be described later, the side surfaces of the conductive layer 151b may not be partially covered with the insulating layer 156.

[0280] When the conductive layer 151 has the structure shown in FIG. 6A, the conductive layer 152 is provided to cover the conductive layers 151a, 151b, 151c, and the insulating layer 156 and to be electrically connected to the conductive layers 151a, 151b, and 151c. This prevents a chemical solution from contacting any of the conductive layers 151a, 151b, and 151c, even when a film formed after the formation of the conductive layer 152 is removed by wet etching. This prevents corrosion from occurring in any of the conductive layers 151a, 151b, and 151c. Therefore, the light-emitting device 1000 can be manufactured with a high yield. Furthermore, the occurrence of defects is suppressed, and the light-emitting device 1000 can be a highly reliable light-emitting device.

[0281] 6(A), the insulating layer 156 preferably has a curved surface. This can prevent discontinuities in the conductive layer 152 covering the insulating layer 156, compared to when the side surfaces of the insulating layer 156 are vertical (parallel to the Z direction). Even when the insulating layer 156 has a tapered shape on the side surface, specifically a tapered shape with a taper angle of less than 90°, the occurrence of discontinuities in the conductive layer 152 covering the insulating layer 156 can be prevented, compared to when the side surfaces of the insulating layer 156 are vertical. As described above, the light-emitting device 1000 can be manufactured by a method with a high yield. Furthermore, the occurrence of defects can be prevented, and the light-emitting device 1000 can be a highly reliable light-emitting device.

[0282] 6A shows a structure in which the side surface of the conductive layer 151b is located inside the side surface of the conductive layer 151a; however, this is not a limitation of one embodiment of the present invention. For example, the side surface of the conductive layer 151b may be located outside the side surface of the conductive layer 151a. Alternatively, the side surface of the conductive layer 151b may be located outside the side surface of the conductive layer 151c.

[0283] 6(B) to 6(D) show other structures of the first electrode 101. Fig. 6(B) shows a structure in which the insulating layer 156 covers not only the side surface of the conductive layer 151b but also the side surfaces of the conductive layer 151a, the conductive layer 151b, and the conductive layer 151c in the first electrode 101 of Fig. 6(A).

[0284] FIG. 6C shows a structure in which the insulating layer 156 is not provided in the first electrode 101 of FIG. 6A.

[0285] FIG. 6D shows a structure in which the conductive layer 151 does not have a layered structure and the conductive layer 152 has a layered structure in the first electrode 101 of FIG. 6A.

[0286] The conductive layer 152a has higher adhesion to the conductive layer 152b than the insulating layer 175, for example. The conductive layer 152a can be formed using an oxide containing one or more of indium, tin, zinc, gallium, titanium, aluminum, and silicon. For example, a conductive oxide containing one or more of indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide containing gallium, titanium oxide, indium titanium oxide, zinc titanate, aluminum zinc oxide, indium zinc oxide containing gallium, indium zinc oxide containing aluminum, indium tin oxide containing silicon, and indium zinc oxide containing silicon can be preferably used. This can prevent peeling of the conductive layer 152b. Furthermore, the conductive layer 152b can be configured not to be in contact with the insulating layer 175.

[0287] The conductive layer 152b has a higher reflectance to visible light (for example, reflectance to light with a predetermined wavelength in the range of 400 nm to 750 nm) than the conductive layer 151, the conductive layer 152a, and the conductive layer 152c. The reflectance of the conductive layer 152b to visible light can be, for example, 40% to 100%, preferably 70% to 100%. The conductive layer 152b can be made of a material having a higher reflectance to visible light than aluminum. Specifically, the conductive layer 152b can be made of, for example, silver or an alloy containing silver. An example of an alloy containing silver is an alloy of silver, palladium, and copper (APC). As described above, the light-emitting device 1000 can have high light extraction efficiency. The conductive layer 152b may be made of a metal other than silver.

[0288] When the conductive layer 151 and the conductive layer 152 function as anodes, the conductive layer 152c preferably has a high work function. The conductive layer 152c has a work function higher than that of the conductive layer 152b, for example. The conductive layer 152c can be formed using the same material as that of the conductive layer 152a. For example, the conductive layer 152a and the conductive layer 152c can be formed using the same material. For example, when indium tin oxide is used for the conductive layer 152a, indium tin oxide can also be used for the conductive layer 152c.

[0289] When the conductive layers 151 and 152 function as cathodes, the conductive layer 152c preferably has a low work function, for example, a work function smaller than that of the conductive layer 152b.

[0290] Further, the conductive layer 152c is preferably a layer having a high transmittance with respect to visible light (for example, the transmittance with respect to light of a predetermined wavelength within the range of 400 nm or more and less than 750 nm). For example, the transmittance of the conductive layer 152c with respect to visible light is preferably higher than the transmittance of the conductive layer 151 and the conductive layer 152b with respect to visible light. For example, the transmittance of the conductive layer 152c with respect to visible light can be 40% or more and 100% or less, preferably 60% or more and 100% or less, more preferably 70% or more and 100% or less, and still more preferably 80% or more and 100% or less. Thus, among the light emitted from the organic compound layer 103, the light absorbed by the conductive layer 152c can be reduced. Further, as described above, the conductive layer 152b under the conductive layer 152c can be a layer having a high reflectance with respect to visible light. Therefore, the light-emitting device 1000 can be a light-emitting device having high light extraction efficiency.

[0291] Subsequently, an example of a method for manufacturing the light-emitting device 1000 having the configuration shown in FIG. 5(A) will be described with reference to FIGS. 7 to 15. The light-emitting device included in the light-emitting device 1000 has an organic compound layer formed by a manufacturing process including a treatment using water. By applying the light-emitting device of one aspect of the present invention as the light-emitting device included in the light-emitting device of the present invention, it is possible to provide a light-emitting device having a light-emitting device with a reduced driving voltage and high luminous efficiency.

[0292] [Example of manufacturing method] The thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device can be formed using a sputtering method, a chemical vapor deposition (CVD) method, a vacuum evaporation method, a pulsed laser deposition (PLD) method, an ALD method, or the like. As the CVD method, there are a plasma enhanced CVD (PECVD) method and a thermal CVD method. Further, one of the thermal CVD methods is a metal organic CVD (MOCVD) method.

[0293] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) that constitute the display device can be formed by wet film formation methods such as spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, or knife coating.

[0294] In particular, vacuum processes such as vapor deposition and solution processes such as spin coating and inkjet printing can be used to fabricate light-emitting devices. Vapor deposition methods include physical vapor deposition (PVD) methods such as sputtering, ion plating, ion beam deposition, molecular beam deposition, and vacuum deposition, and chemical vapor deposition (CVD). In particular, functional layers included in the organic compound layer (e.g., hole injection layer, hole transport layer, hole blocking layer, light-emitting layer, electron blocking layer, electron transport layer, and electron injection layer) can be formed by vapor deposition (e.g., vacuum deposition), coating methods (e.g., dip coating, die coating, bar coating, spin coating, and spray coating), printing methods (e.g., inkjet printing, screen printing, offset printing, flexography, gravure printing, and microcontact printing).

[0295] Furthermore, when processing the thin film that constitutes the display device, it can be processed using, for example, a lithography method. Alternatively, the thin film may be processed using a nanoimprint method, a sandblasting method, a lift-off method, etc. Furthermore, the island-shaped thin film may be directly formed by a film formation method using a shielding mask such as a metal mask.

[0296] As a lithography method, for example, photolithography can be used. There are two typical photolithography methods: one is a method in which a resist mask is formed on a thin film to be processed, the thin film is processed by, for example, etching, and then the resist mask is removed; the other is a method in which a photosensitive thin film is formed, and then the thin film is exposed to light and developed to be processed into a desired shape.

[0297] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these. Other light sources that can be used include ultraviolet light, KrF laser light, and ArF laser light. Exposure can also be performed by immersion exposure technology. Extreme ultraviolet (EUV) light or X-rays can also be used as the light used for exposure. An electron beam can also be used instead of the light used for exposure. Extreme ultraviolet light, X-rays, or an electron beam are preferred because they enable extremely fine processing. When exposure is performed by scanning a beam such as an electron beam, a photomask is not required.

[0298] The thin film can be etched by dry etching, wet etching, sandblasting, or the like.

[0299] 7A, an insulating layer 171 is formed on a substrate (not shown). Subsequently, conductive layers 172 and 179 are formed on the insulating layer 171, and an insulating layer 173 is formed on the insulating layer 171 so as to cover the conductive layers 172 and 179. Subsequently, an insulating layer 174 is formed on the insulating layer 173, and an insulating layer 175 is formed on the insulating layer 174.

[0300] The substrate may be a substrate having heat resistance sufficient to withstand at least subsequent heat treatment. When an insulating substrate is used, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, an organic resin substrate, or the like may be used. Also, a semiconductor substrate such as a single-crystal semiconductor substrate made of silicon or silicon carbide, a polycrystalline semiconductor substrate, a compound semiconductor substrate such as silicon germanium, or an SOI substrate may be used.

[0301] 7A, openings are formed in the insulating layers 175, 174, and 173, reaching the conductive layer 172. Then, plugs 176 are formed to fill the openings.

[0302] 7A, a conductive film 151f, which will later become the conductive layers 151R, 151G, 151B, and 151C, is formed on the plug 176 and the insulating layer 175. The conductive film 151f can be formed by, for example, sputtering or vacuum evaporation. The conductive film 151f can be made of, for example, a metal material.

[0303] 7A, a conductive film 152f, which will later become the conductive layers 152R, 152G, 152B, and 152C, is formed over the conductive film 151f. The conductive film 152f can be formed by, for example, a sputtering method or a vacuum evaporation method. The conductive film 152f can be formed using, for example, a conductive oxide. Alternatively, the conductive film 152f can have a stacked structure of a film using a metal material and a film using a conductive oxide thereon. For example, the conductive film 152f can have a stacked structure of a film using titanium, silver, or an alloy containing silver and a film using a conductive oxide thereon.

[0304] The conductive film 152f can be formed by an ALD method. In this case, the conductive film 152f can be made of an oxide containing one or more elements selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon. The conductive film 152f can be formed by repeating a cycle consisting of introducing a precursor (which may be generally referred to as a precursor or metal precursor), purging the precursor, introducing an oxidizing agent (which may be generally referred to as a reactant, reactant, or non-metal precursor), and purging the oxidizing agent. When forming the conductive film 152f as an oxide film containing multiple metals, such as indium tin oxide, the metal composition can be controlled by varying the number of cycles for each type of precursor.

[0305] For example, when forming an indium tin oxide film as the conductive film 152f, an indium-containing precursor is introduced, the precursor is purged, an oxidizer is introduced, and an In—O film is formed. Next, a tin-containing precursor is introduced, the precursor is purged, and an oxidizer is introduced, and an Sn—O film is formed. Here, by increasing the number of cycles for forming the In—O film compared to the number of cycles for forming the Sn—O film, the number of In atoms contained in the conductive film 152f can be made larger than the number of Sn atoms.

[0306] Furthermore, for example, when a zinc oxide film is formed as the conductive film 152f, a Zn-O film is formed using the above procedure. For example, when an aluminum zinc oxide film is formed as the conductive film 152f, a Zn-O film and an Al-O film are formed using the above procedure. For example, when a titanium oxide film is formed as the conductive film 152f, a Ti-O film is formed using the above procedure. For example, when an indium tin oxide film containing silicon is formed as the conductive film 152f, an In-O film, an Sn-O film, and an Si-O film are formed using the above procedure. For example, when a zinc oxide film containing gallium is formed, a Ga-O film and a Zn-O film are formed using the above procedure.

[0307] Examples of precursors that can be used include indium-containing precursors such as triethylindium, trimethylindium, or [1,1,1-trimethyl-N-(trimethylsilyl)amido]-indium. Examples of precursors that can be used include tin chloride or tetrakis(dimethylamido)tin. Examples of precursors that can be used include zinc-containing precursors such as diethylzinc or dimethylzinc. Examples of precursors that can be used include gallium-containing precursors such as triethylgallium. Examples of precursors that can be used include titanium chloride, tetrakis(dimethylamido)titanium, or tetraisopropyl titanate. Examples of precursors that can be used include aluminum chloride or trimethylaluminum. Examples of precursors that can be used include silicon-containing precursors such as trisilylamine, bis(diethylamino)silane, tris(dimethylamino)silane, bis(tert-butylamino)silane, or bis(ethylmethylamino)silane. Examples of oxidizing agents include water vapor, oxygen plasma, or ozone gas.

[0308] 7A, a resist mask 191 is formed over the conductive film 151f and the conductive film 152f. The resist mask 191 can be formed by applying a photosensitive material (photoresist), exposing it to light, and developing it.

[0309] 7B, for example, the conductive films 151f and 152f in regions that do not overlap with the resist mask 191 are removed by, for example, etching, specifically, dry etching, to form a pixel electrode including the conductive layer 151 and the conductive layer 152. Note that when the conductive film 151f includes a layer using a conductive oxide such as indium tin oxide, the layer may be removed by wet etching. Note that, for example, when part of the conductive film 151f is removed by dry etching, a recess may be formed in a region of the insulating layer 175 that does not overlap with the conductive layer 151.

[0310] Note that the conductive film 152f may be processed by lithography to form the conductive layers 152R, 152G, 152B, and 152C, and then the conductive film 151f may be processed using the conductive layers 152R, 152G, 152B, and 152C as masks. Specifically, for example, after forming a resist mask, part of the conductive film 152f is removed by etching. The conductive film 152f can be removed by, for example, wet etching. The conductive film 152f may also be removed by dry etching. After that, the conductive film 151f may be removed by wet etching.

[0311] Here, it is preferable to perform hydrophobic treatment on the conductive layer 152. The hydrophobic treatment can change the surface to be treated from hydrophilic to hydrophobic, or can increase the hydrophobicity of the surface to be treated. By performing the hydrophobic treatment on the conductive layer 152, adhesion between the conductive layer 152 and the organic compound layer 103 formed in a later step can be improved, and film peeling can be suppressed. Note that the hydrophobic treatment is not necessarily performed.

[0312] 7(C), the resist mask 191 is removed. The resist mask 191 can be removed by ashing using oxygen plasma, for example. Alternatively, oxygen gas and a Group 18 element such as CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or He may be used. Alternatively, the resist mask 191 may be removed by wet etching.

[0313] 7(D), an insulating film 156f, which will later become the insulating layer 156R, the insulating layer 156G, the insulating layer 156B, and the insulating layer 156C, is formed on the conductive layer 151R and the conductive layer 152R, the conductive layer 151G and the conductive layer 152G, the conductive layer 151B and the conductive layer 152B, the conductive layer 151C and the conductive layer 152C, and the insulating layer 175. The insulating film 156f can be formed by, for example, a CVD method, an ALD method, a sputtering method, or a vacuum deposition method.

[0314] The insulating film 156f can be formed using an inorganic material. For example, the insulating film 156f can be formed using an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film. For example, the insulating film 156f can be formed using an oxide insulating film containing silicon, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film. For example, the insulating film 156f can be formed using silicon oxynitride.

[0315] 7(E), the insulating film 156f is processed to form insulating layers 156R, 156G, 156B, and 156C. For example, the insulating layer 156 can be formed by uniformly etching the upper surface of the insulating film 156f. Such uniform etching and planarization is also called an etch-back process. The insulating layer 156 may also be formed using lithography.

[0316] Next, as shown in FIG. 8(A), an organic compound film 103Rf, which will later become the organic compound layer 103R, is formed on the conductive layer 152R, the conductive layer 152G, the conductive layer 152B, the insulating layer 156R, the insulating layer 156G, the insulating layer 156B, and the insulating layer 175.

[0317] 8A, the organic compound film 103Rf is not formed on the conductive layer 152C. For example, by using a mask for defining the film formation area (also called an area mask or a rough metal mask to distinguish it from a fine metal mask), the organic compound film 103Rf can be formed only in the desired region. By employing a film formation process using an area mask and a processing process using a resist mask, the light-emitting device can be manufactured through a relatively simple process.

[0318] The organic compound film 103Rf can be formed by, for example, a vapor deposition method, specifically a vacuum deposition method, or may be formed by a transfer method, a printing method, an inkjet method, a coating method, or the like.

[0319] Next, as shown in FIG. 8(A), a sacrificial film 158Rf, which will later become the sacrificial layer 158R, and a mask film 159Rf, which will later become the mask layer 159R, are formed in this order on the organic compound film 103Rf, the conductive layer 152C, and the insulating layer 175.

[0320] In this embodiment, an example is shown in which the mask film is formed with a two-layer structure of the sacrificial film 158Rf and the mask film 159Rf, but the mask film may have a single-layer structure or a laminated structure of three or more layers. Also, in this specification, the mask layer may be referred to as a sacrificial layer.

[0321] By providing a sacrificial layer on the organic compound film 103Rf, damage to the organic compound film 103Rf during the manufacturing process of the display device can be reduced, and the reliability of the light-emitting device can be improved.

[0322] The sacrificial film 158Rf is made of a film that is highly resistant to the processing conditions of the organic compound film 103Rf, specifically, a film that has a large etching selectivity with respect to the organic compound film 103Rf.The mask film 159Rf is made of a film that has a large etching selectivity with respect to the sacrificial film 158Rf.

[0323] The sacrificial film 158Rf and the mask film 159Rf are formed at a temperature lower than the heat-resistant temperature of the organic compound film 103Rf. The substrate temperatures when forming the sacrificial film 158Rf and the mask film 159Rf are typically 200° C. or lower, preferably 150° C. or lower, more preferably 120° C. or lower, more preferably 100° C. or lower, and even more preferably 80° C. or lower.

[0324] The sacrificial film 158Rf and the mask film 159Rf are preferably made of films that can be removed by wet etching, which can reduce damage to the organic compound film 103Rf when processing the sacrificial film 158Rf and the mask film 159Rf compared to when dry etching is used.

[0325] The sacrificial film 158Rf and the mask film 159Rf can be formed by, for example, sputtering, ALD (thermal ALD, PEALD), CVD, or vacuum deposition. Alternatively, they may be formed by the wet film formation method described above.

[0326] The sacrificial film 158Rf formed on and in contact with the organic compound film 103Rf is preferably formed using a formation method that causes less damage to the organic compound film 103Rf than the mask film 159Rf. For example, it is preferable to form the sacrificial film 158Rf using the ALD method or the vacuum deposition method rather than the sputtering method.

[0327] The sacrificial film 158Rf and the mask film 159Rf may each be made of one or more of a metal film, an alloy film, a metal oxide film, a semiconductor film, an organic insulating film, an inorganic insulating film, or the like.

[0328] The sacrificial film 158Rf and the mask film 159Rf can be made of metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloy materials containing such metal materials. It is particularly preferable to use a low-melting-point material such as aluminum or silver. Using a metal material capable of blocking ultraviolet rays for one or both of the sacrificial film 158Rf and the mask film 159Rf is preferable because it can prevent ultraviolet rays from being irradiated onto the organic compound film 103Rf and suppress deterioration of the organic compound film 103Rf.

[0329] Furthermore, for the sacrificial film 158Rf and the mask film 159Rf, metal oxides such as In-Ga-Zn oxide, indium oxide, In-Zn oxide, In-Sn oxide, indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), and indium tin oxide containing silicon can be used, respectively.

[0330] In addition, instead of the above gallium, an element M (M is one or more elements selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) may be used.

[0331] Furthermore, it is preferable to use a film containing a material that has light-shielding properties against light, particularly ultraviolet light, as the sacrificial film and the mask film. As the light-shielding material, various materials such as metals, insulators, semiconductors, and semimetals that have light-shielding properties against ultraviolet light can be used, but since part or all of the sacrificial film and the mask film will be removed in a later step, it is preferable that the film be a film that can be processed by etching, and it is particularly preferable that the film have good processability.

[0332] For the sacrificial film and mask film, it is preferable to use semiconductor materials such as silicon or germanium because they have high compatibility with semiconductor manufacturing processes. Alternatively, oxides or nitrides of the above semiconductor materials can be used. Alternatively, non-metallic materials such as carbon or their compounds can be used. Alternatively, metals such as titanium, tantalum, tungsten, chromium, and aluminum, or alloys containing one or more of these, can be used. Alternatively, oxides containing the above metals such as titanium oxide or chromium oxide, or nitrides such as titanium nitride, chromium nitride, or tantalum nitride can be used.

[0333] By using a film containing a material that blocks ultraviolet light for the sacrificial film and the mask film, it is possible to prevent the organic compound layer from being irradiated with ultraviolet light during, for example, an exposure process, and by preventing the organic compound layer from being damaged by ultraviolet light, the reliability of the light-emitting device can be improved.

[0334] It should be noted that a film containing a material that has a light-shielding property against ultraviolet rays can also achieve the same effect when used as the material for the inorganic insulating film 125f, which will be described later.

[0335] Moreover, various inorganic insulating films can be used for the sacrificial film 158Rf and the mask film 159Rf. In particular, oxide insulating films are preferable because they have higher adhesion to the organic compound film 103Rf than nitride insulating films. For example, inorganic insulating materials such as aluminum oxide, hafnium oxide, and silicon oxide can be used for the sacrificial film 158Rf and the mask film 159Rf. For example, aluminum oxide films can be formed as the sacrificial film 158Rf and the mask film 159Rf using the ALD method. Using the ALD method is preferable because it can reduce damage to the underlying layer (especially the organic compound layer).

[0336] For example, the sacrificial film 158Rf can be an inorganic insulating film (e.g., an aluminum oxide film) formed using the ALD method, and the mask film 159Rf can be an inorganic film (e.g., an In-Ga-Zn oxide film, an aluminum film, or a tungsten film) formed using the sputtering method.

[0337] The same inorganic insulating film can be used for both the sacrificial film 158Rf and the inorganic insulating layer 125 to be formed later. For example, an aluminum oxide film formed using the ALD method can be used for both the sacrificial film 158Rf and the inorganic insulating layer 125. The sacrificial film 158Rf and the inorganic insulating layer 125 may be formed under the same or different film-forming conditions. For example, by forming the sacrificial film 158Rf under the same conditions as the inorganic insulating layer 125, the sacrificial film 158Rf can be an insulating layer with high barrier properties against at least one of water and oxygen. On the other hand, since the sacrificial film 158Rf is a layer that will be mostly or completely removed in a later process, it is preferable that it be easily processed. For this reason, the sacrificial film 158Rf is preferably formed under conditions where the substrate temperature during film formation is lower than that of the inorganic insulating layer 125.

[0338] An organic material may be used for one or both of the sacrificial film 158Rf and the mask film 159Rf. For example, the organic material may be a material that is soluble in a chemically stable solvent, at least for the film located at the top of the organic compound film 103Rf. Materials that dissolve in water or alcohol are particularly suitable. When forming a film of such a material, it is preferable to apply the material dissolved in a solvent such as water or alcohol by a wet film formation method, and then perform a heat treatment to evaporate the solvent. In this case, performing the heat treatment under a reduced pressure atmosphere is preferable because it allows the solvent to be removed at a low temperature and in a short time, thereby reducing thermal damage to the organic compound film 103Rf.

[0339] The sacrificial film 158Rf and the mask film 159Rf may each be made of an organic resin such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, alcohol-soluble polyamide resin, or a fluororesin such as a perfluoropolymer.

[0340] For example, the sacrificial film 158Rf may be an organic film (e.g., a PVA film) formed using either a vapor deposition method or the above-mentioned wet film formation method, and the mask film 159Rf may be an inorganic film (e.g., a silicon nitride film) formed using a sputtering method.

[0341] 8(A), a resist mask 190R is formed on the mask film 159Rf. The resist mask 190R can be formed by applying a photosensitive material (photoresist) and then performing exposure and development.

[0342] The resist mask 190R may be made of either a positive resist material or a negative resist material.

[0343] The resist mask 190R is provided in a position overlapping with the conductive layer 152R. The resist mask 190R is preferably also provided in a position overlapping with the conductive layer 152C. This can prevent the conductive layer 152C from being damaged during the manufacturing process of the display device. Note that the resist mask 190R does not necessarily have to be provided on the conductive layer 152C. Furthermore, as shown in the cross-sectional view between B1 and B2 in FIG. 8A, the resist mask 190R is preferably provided so as to cover from the end of the organic compound film 103Rf to the end of the conductive layer 152C (the end on the organic compound film 103Rf side).

[0344] 8(B), a resist mask 190R is used to remove a portion of the mask film 159Rf to form a mask layer 159R. The mask layer 159R remains on the conductive layer 152R and the conductive layer 152C. The resist mask 190R is then removed. The mask layer 159R is used as a mask (also referred to as a hard mask) to remove a portion of the sacrificial film 158Rf to form a sacrificial layer 158R.

[0345] The sacrificial film 158Rf and the mask film 159Rf can be processed by wet etching or dry etching, respectively. The sacrificial film 158Rf and the mask film 159Rf are preferably processed by isotropic etching.

[0346] By using the wet etching method, damage to the organic compound film 103Rf during processing of the sacrificial film 158Rf and the mask film 159Rf can be reduced compared to when using the dry etching method. When using the wet etching method, it is preferable to use a chemical solution such as a developer, a tetramethylammonium hydroxide (TMAH) aqueous solution, diluted hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof.

[0347] In processing the mask film 159Rf, the organic compound film 103Rf is not exposed, so the range of processing methods to be selected is wider than in processing the sacrificial film 158Rf. Specifically, even when a gas containing oxygen is used as an etching gas in processing the mask film 159Rf, deterioration of the organic compound film 103Rf can be further suppressed.

[0348] Furthermore, when dry etching is used to process the sacrificial film 158Rf, deterioration of the organic compound film 103Rf can be suppressed by not using a gas containing oxygen as the etching gas. When dry etching is used, it is preferable to use a gas containing a Group 18 element such as CF4, C4F8, SF6, CHF3, Cl2, HO, BCl3, or He as the etching gas.

[0349] For example, when an aluminum oxide film formed by ALD is used as the sacrificial film 158Rf, a portion of the sacrificial film 158Rf can be removed by dry etching using CHF3 and He, or CHF3, He, and CH4. When an In-Ga-Zn oxide film formed by sputtering is used as the mask film 159Rf, a portion of the mask film 159Rf can be removed by wet etching using diluted phosphoric acid. Alternatively, a portion of the mask film 159Rf may be removed by dry etching using CH4 and Ar. Alternatively, a portion of the mask film 159Rf can be removed by wet etching using diluted phosphoric acid. When a tungsten film formed by sputtering is used as the mask film 159Rf, a portion of the mask film 159Rf can be removed by dry etching using SF6, CF4 and O2, or CF4, Cl2, and O2.

[0350] The resist mask 190R can be removed by the same method as the resist mask 191. For example, it can be removed by ashing using oxygen plasma. Alternatively, oxygen gas and a Group 18 element such as CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or He may be used. Alternatively, the resist mask 190R may be removed by wet etching. At this time, since the sacrificial film 158Rf is located on the outermost surface and the organic compound film 103Rf is not exposed, damage to the organic compound film 103Rf can be suppressed in the process of removing the resist mask 190R. Furthermore, the range of options for removing the resist mask 190R can be expanded.

[0351] 8(B), the organic compound film 103Rf is processed to form the organic compound layer 103R. For example, the mask layer 159R and the sacrificial layer 158R are used as a hard mask to remove a part of the organic compound film 103Rf, thereby forming the organic compound layer 103R.

[0352] 8B, a stacked structure of the organic compound layer 103R, the sacrificial layer 158R, and the mask layer 159R remains on the conductive layer 152R. Also, the conductive layers 152G and 152B are exposed.

[0353] 8B shows an example in which the edge of the organic compound layer 103R is located inside the edge of the conductive layer 152R. This structure enables miniaturization of pixels, enabling the creation of a high-resolution display. Although not shown in FIG. 8B, the etching process may result in the formation of a recess in a region of the insulating layer 175 that does not overlap with the organic compound layer 103R.

[0354] As described above, the resist mask 190R is preferably provided to cover the area between the dashed-dotted lines B1-B2 from the end of the organic compound layer 103R to the end of the conductive layer 152C (the end on the organic compound layer 103R side). As a result, as shown in FIG. 8B, the sacrificial layer 158R and the mask layer 159R are provided to cover the area between the dashed-dotted lines B1-B2 from the end of the organic compound layer 103R to the end of the conductive layer 152C (the end on the organic compound layer 103R side). This prevents the insulating layer 175 from being exposed between the dashed-dotted lines B1-B2, for example. This prevents the conductive layer 179 from being exposed when parts of the insulating layers 175, 174, and 173 are removed by etching or the like. This prevents the conductive layer 179 from being unintentionally electrically connected to other conductive layers. For example, this prevents a short circuit between the conductive layer 179 and the common electrode 155 formed in a later process.

[0355] The organic compound film 103Rf is preferably processed by anisotropic etching, particularly anisotropic dry etching, or wet etching may be used.

[0356] When dry etching is used, deterioration of the organic compound film 103Rf can be suppressed by not using an oxygen-containing gas as the etching gas.

[0357] Alternatively, an etching gas containing oxygen may be used. The etching rate can be increased by using an etching gas containing oxygen. Therefore, etching can be performed under low power conditions while maintaining a sufficiently high etching rate. This can reduce damage to the organic compound film 103Rf. Furthermore, problems such as adhesion of reaction products generated during etching can be reduced.

[0358] When dry etching is used, it is preferable to use a gas containing one or more of H2, CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or Group 18 elements such as He and Ar as the etching gas. Alternatively, it is preferable to use a gas containing one or more of these elements and oxygen as the etching gas. Alternatively, oxygen gas may be used as the etching gas. Specifically, for example, a gas containing H2 and Ar, or a gas containing CF4 and He can be used as the etching gas. Alternatively, for example, a gas containing CF4, He, and oxygen can be used as the etching gas. Alternatively, for example, a gas containing H2 and Ar, or a gas containing oxygen can be used as the etching gas.

[0359] As described above, in one embodiment of the present invention, the resist mask 190R is formed over the mask film 159Rf, and part of the mask film 159Rf is removed using the resist mask 190R to form the mask layer 159R. Then, part of the organic compound film 103Rf is removed using the mask layer 159R as a hard mask to form the organic compound layer 103R. Therefore, it can be said that the organic compound layer 103R is formed by processing the organic compound film 103Rf using a lithography method. Note that part of the organic compound film 103Rf may be removed using the resist mask 190R. Then, the resist mask 190R may be removed.

[0360] Next, it is preferable to perform, for example, a hydrophobic treatment on the conductive layer 152G. When processing the organic compound film 103Rf, for example, the surface state of the conductive layer 152G may change to a hydrophilic state. For example, by performing a hydrophobic treatment on the conductive layer 152G, it is possible to improve the adhesion between the conductive layer 152G and a layer (here, the organic compound layer 103G) formed in a later step, and to suppress film peeling. Note that the hydrophobic treatment is not necessarily required.

[0361] Next, as shown in FIG. 9(A), an organic compound film 103Gf, which will later become the organic compound layer 103G, is formed on the conductive layer 152G, the conductive layer 152B, the insulating layer 156R, the insulating layer 156G, the insulating layer 156B, the mask layer 159R, and the insulating layer 175.

[0362] The organic compound film 103Gf can be formed by the same method as that used to form the organic compound film 103Rf, and can have the same structure as the organic compound film 103Rf.

[0363] 9A, a sacrificial film 158Gf, which will later become the sacrificial layer 158G, and a mask film 159Gf, which will later become the mask layer 159G, are sequentially formed on the organic compound film 103Gf and the mask layer 159R. A resist mask 190G is then formed. The materials and formation methods for the sacrificial film 158Gf and the mask film 159Gf are the same as those applicable to the sacrificial film 158Rf and the mask film 159Rf. The materials and formation methods for the resist mask 190G are the same as those applicable to the resist mask 190R.

[0364] The resist mask 190G is provided in a position overlapping with the conductive layer 152G.

[0365] 9(B), a resist mask 190G is used to remove a portion of the mask film 159Gf to form a mask layer 159G. The mask layer 159G remains on the conductive layer 152G. The resist mask 190G is then removed. The mask layer 159G is then used as a mask to remove a portion of the sacrificial film 158Gf to form a sacrificial layer 158G. The organic compound film 103Gf is then processed to form an organic compound layer 103G. For example, the mask layer 159G and the sacrificial layer 158G are used as hard masks to remove a portion of the organic compound film 103Gf to form the organic compound layer 103G.

[0366] 9B, a stacked structure of the organic compound layer 103G, the sacrificial layer 158G, and the mask layer 159G remains on the conductive layer 152G, and the mask layer 159R and the conductive layer 152B are exposed.

[0367] Next, it is preferable to perform, for example, a hydrophobic treatment on the conductive layer 152B. When processing the organic compound film 103Gf, for example, the surface state of the conductive layer 152B may change to a hydrophilic state. For example, by performing a hydrophobic treatment on the conductive layer 152B, it is possible to improve the adhesion between the conductive layer 152B and a layer (here, the organic compound layer 103B) formed in a later step, and to suppress film peeling. Note that the hydrophobic treatment is not necessarily required.

[0368] Next, as shown in FIG. 9(C), an organic compound film 103Bf, which will later become the organic compound layer 103B, is formed on the conductive layer 152B, the insulating layer 156R, the insulating layer 156G, the insulating layer 156B, the mask layer 159R, the mask layer 159G, and the insulating layer 175.

[0369] The organic compound film 103Bf can be formed by the same method as that used to form the organic compound film 103Rf, and can have the same structure as the organic compound film 103Rf.

[0370] 9(C), a sacrificial film 158Bf, which will later become the sacrificial layer 158B, and a mask film 159Bf, which will later become the mask layer 159B, are sequentially formed on the organic compound film 103Bf and the mask layer 159R. A resist mask 190B is then formed. The materials and formation methods for the sacrificial film 158Bf and the mask film 159Bf are the same as those applicable to the sacrificial film 158Rf and the mask film 159Rf. The materials and formation methods for the resist mask 190B are the same as those applicable to the resist mask 190R.

[0371] The resist mask 190B is provided in a position overlapping with the conductive layer 152B.

[0372] 9(D), a resist mask 190B is used to remove a portion of the mask film 159Bf to form a mask layer 159B. The mask layer 159B remains on the conductive layer 152B. The resist mask 190B is then removed. The mask layer 159B is used as a mask to remove a portion of the sacrificial film 158Bf to form a sacrificial layer 158B. The organic compound film 103Bf is then processed to form the organic compound layer 103B. For example, the mask layer 159B and the sacrificial layer 158B are used as hard masks to remove a portion of the organic compound film 103Bf to form the organic compound layer 103B.

[0373] 9D, a stacked structure of the organic compound layer 103B, the sacrificial layer 158B, and the mask layer 159B remains on the conductive layer 152B, and the mask layers 159R and 159G are exposed.

[0374] It is preferable that the side surfaces of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B are perpendicular or approximately perpendicular to the surface on which they are formed. For example, it is preferable that the angle formed between the surface on which they are formed and these side surfaces is 60 degrees or more and 90 degrees or less.

[0375] As described above, the distance between adjacent pairs of the organic compound layers 103R, 103G, and 103B formed using lithography can be narrowed to 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. Here, the distance can be defined, for example, as the distance between the opposing ends of adjacent pairs of the organic compound layers 103R, 103G, and 103B. By narrowing the distance between the island-shaped organic compound layers in this manner, a display device with high definition and a large aperture ratio can be provided. Furthermore, the distance between the first electrodes of adjacent light-emitting devices can also be narrowed, for example, to 10 μm or less, 8 μm or less, 5 μm or less, 3 μm or less, or 2 μm or less. It is preferable that the distance between the first electrodes of adjacent light-emitting devices be 2 μm or more and 5 μm or less.

[0376] 10A, it is preferable to remove the mask layers 159R, 159G, and 159B. Depending on the subsequent process, the sacrificial layers 158R, 158G, and 158B, and the mask layers 159R, 159G, and 159B may remain in the display device. By removing the mask layers 159R, 159G, and 159B at this stage, it is possible to prevent the mask layers 159R, 159G, and 159B from remaining in the display device. For example, when a conductive material is used for the mask layers 159R, 159G, and 159B, removing the mask layers 159R, 159G, and 159B in advance can prevent leakage current and capacitance from being generated by the remaining mask layers 159R, 159G, and 159B.

[0377] Although the present embodiment will be described taking as an example a case where the mask layers 159R, 159G, and 159B are removed, it is not necessary to remove the mask layers 159R, 159G, and 159B. For example, if the mask layers 159R, 159G, and 159B contain the aforementioned material that has a light-blocking property against ultraviolet light, it is preferable to proceed to the next step without removing them, because this protects the organic compound layer from ultraviolet light.

[0378] The mask layer removal process can be performed using the same method as the mask film processing process. In particular, wet etching can reduce damage to the organic compound layers 103R, 103G, and 103B when removing the mask layer compared to dry etching.

[0379] The mask layer may also be removed by dissolving it in a solvent such as water or alcohol, such as ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin.

[0380] After removing the mask layer, a drying treatment may be performed to remove water contained in the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B, as well as water adsorbed on the surfaces of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B. For example, a heat treatment can be performed in an inert gas atmosphere or a reduced-pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50°C or higher and 200°C or lower, preferably 60°C or higher and 150°C or lower, and more preferably 70°C or higher and 120°C or lower. A reduced-pressure atmosphere is preferred because it enables drying at a lower temperature.

[0381] Next, as shown in FIG. 10(B), an inorganic insulating film 125f, which will later become the inorganic insulating layer 125, is formed to cover the organic compound layer 103R, the organic compound layer 103G, the organic compound layer 103B, the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B.

[0382] As will be described later, an insulating film 127f, which will later become the insulating layer 127, is formed in contact with the upper surface of the inorganic insulating film 125f. For this reason, it is preferable that the upper surface of the inorganic insulating film 125f has a high affinity with the material used for the insulating film (e.g., a photosensitive resin composition containing an acrylic resin). To improve this affinity, it is preferable to hydrophobize (or increase the hydrophobicity of) the upper surface of the inorganic insulating film 125f by performing a surface treatment. For example, it is preferable to perform the treatment using a silylating agent such as hexamethyldisilazane (HMDS). By hydrophobizing the upper surface of the inorganic insulating film 125f in this way, the insulating film 127f can be formed with good adhesion. Note that the surface treatment may be the hydrophobization treatment described above.

[0383] Subsequently, as shown in FIG. 10(C), an insulating film 127f, which will later become the insulating layer 127, is formed on the inorganic insulating film 125f.

[0384] The inorganic insulating film 125f and the insulating film 127f are preferably formed by a formation method that causes less damage to the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B. In particular, since the inorganic insulating film 125f is formed in contact with the side surfaces of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B, it is preferably formed by a formation method that causes less damage to the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B than the insulating film 127f.

[0385] The inorganic insulating film 125f and the insulating film 127f are formed at a temperature lower than the heat-resistant temperatures of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B, respectively. By increasing the substrate temperature during film formation, the inorganic insulating film 125f can be formed into a film with a low impurity concentration and a high barrier property against at least one of water and oxygen, even if it is thin.

[0386] The substrate temperature when forming the inorganic insulating film 125f and the insulating film 127f is preferably 60°C or higher, 80°C or higher, 100°C or higher, or 120°C or higher, and 200°C or lower, 180°C or lower, 160°C or lower, 150°C or lower, or 140°C or lower, respectively.

[0387] As the inorganic insulating film 125f, it is preferable to form an insulating film having a thickness of 3 nm or more, 5 nm or more, or 10 nm or more, and 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less within the above substrate temperature range.

[0388] The inorganic insulating film 125f is preferably formed by, for example, the ALD method. The ALD method is preferable because it can reduce film formation damage and also allows for the formation of a film with high coverage. The inorganic insulating film 125f is preferably formed as an aluminum oxide film by, for example, the ALD method.

[0389] Alternatively, the inorganic insulating film 125f may be formed by sputtering, CVD, or PECVD, which have a faster film formation rate than ALD, thereby enabling a highly reliable display device to be manufactured with high productivity.

[0390] The insulating film 127f is preferably formed by the wet film formation method described above. The insulating film 127f is preferably formed by, for example, spin coating using a photosensitive material, more specifically, using a photosensitive resin composition containing an acrylic resin.

[0391] The insulating film 127f is preferably formed using a resin composition containing, for example, a polymer, an acid generator, and a solvent. The polymer is formed using one or more types of monomers and has a structure in which one or more types of structural units (also referred to as constituent units) are regularly or irregularly repeated. As the acid generator, one or both of a compound that generates an acid when irradiated with light and a compound that generates an acid when heated can be used. The resin composition may further contain one or more of a photosensitizer, a sensitizer, a catalyst, an adhesion aid, a surfactant, and an antioxidant.

[0392] Furthermore, heat treatment (also referred to as pre-baking) is preferably performed after the insulating film 127f is formed. The heat treatment is performed at a temperature lower than the heat resistance temperature of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B. The substrate temperature during the heat treatment is preferably 50° C. to 200° C., more preferably 60° C. to 150° C., and still more preferably 70° C. to 120° C. This allows the solvent contained in the insulating film 127f to be removed.

[0393] Next, exposure is performed to expose a portion of the insulating film 127f to visible light or ultraviolet light. If a positive-type photosensitive resin composition containing an acrylic resin is used for the insulating film 127f, visible light or ultraviolet light is irradiated onto the region where the insulating layer 127 will not be formed in a later process. The insulating layer 127 is formed in the region sandwiched between any two of the conductive layers 152R, 152G, and 152B, and around the conductive layer 152C. Therefore, visible light or ultraviolet light is irradiated onto the conductive layers 152R, 152G, 152B, and 152C. If a negative-type photosensitive material is used for the insulating film 127f, visible light or ultraviolet light is irradiated onto the region where the insulating layer 127 will be formed.

[0394] The exposed region of the insulating film 127f can control the width of the insulating layer 127 to be formed later. In this embodiment, the insulating layer 127 is processed so as to have a portion overlapping the upper surface of the conductive layer 151.

[0395] The light used for exposure preferably contains i-line (wavelength 365 nm), and may contain at least one of g-line (wavelength 436 nm) and h-line (wavelength 405 nm).

[0396] Here, by providing an oxygen barrier insulating layer (e.g., an aluminum oxide film) as one or both of the sacrificial layer 158 (the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B) and the inorganic insulating film 125f, it is possible to reduce the diffusion of oxygen into the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B. When the organic compound layer is irradiated with light (visible light or ultraviolet light), the organic compound contained in the organic compound layer becomes excited, which may promote a reaction with oxygen contained in the atmosphere. More specifically, when light (visible light or ultraviolet light) is irradiated to the organic compound layer in an oxygen-containing atmosphere, oxygen may bond to the organic compound contained in the organic compound layer. By providing the sacrificial layer 158 and the inorganic insulating film 125f on the island-shaped organic compound layer, it is possible to reduce the bonding of oxygen in the atmosphere to the organic compound contained in the organic compound layer.

[0397] 11(A), development is performed to remove the exposed region of the insulating film 127f, thereby forming the insulating layer 127a. The insulating layer 127a is formed in a region sandwiched between any two of the conductive layers 152R, 152G, and 152B, and in a region surrounding the conductive layer 152C. When an acrylic resin is used for the insulating film 127f, an alkaline solution, such as TMAH, can be used as the developer.

[0398] Subsequently, residues (so-called scum) remaining after development may be removed, for example, by ashing using oxygen plasma.

[0399] Etching may be performed to adjust the height of the surface of the insulating layer 127a. The insulating layer 127a may be processed by ashing using oxygen plasma, for example. Even when a non-photosensitive material is used as the insulating film 127f, the height of the surface of the insulating film 127f can be adjusted by ashing, for example.

[0400] 11(B), an etching process is performed using the insulating layer 127a as a mask to remove a portion of the inorganic insulating film 125f and reduce the thickness of a portion of the sacrificial layers 158R, 158G, and 158B. As a result, the inorganic insulating layer 125 is formed below the insulating layer 127a. Furthermore, the surfaces of the thin portions of the sacrificial layers 158R, 158G, and 158B are exposed. Note that, hereinafter, the etching process using the insulating layer 127a as a mask may be referred to as the first etching process.

[0401] The first etching process can be performed by dry etching or wet etching. Note that, when the inorganic insulating film 125f is formed using the same material as the sacrificial layers 158R, 158G, and 158B, the first etching process can be performed all at once, which is preferable.

[0402] By performing etching using insulating layer 127a, which has tapered side surfaces, as a mask, the side surfaces of inorganic insulating layer 125 and the upper end portions of the side surfaces of sacrificial layers 158R, 158G, and 158B can be tapered relatively easily.

[0403] When dry etching is performed, it is preferable to use a chlorine-based gas. Examples of chlorine-based gases that can be used include Cl2, BCl3, SiCl4, and CCl4, either singly or in combination. Furthermore, oxygen gas, hydrogen gas, helium gas, and argon gas can be added to the chlorine-based gas, either singly or in combination. By using dry etching, thin-film regions of the sacrificial layers 158R, 158G, and 158B can be formed with good in-plane uniformity.

[0404] The dry etching apparatus may be a dry etching apparatus having a high-density plasma source. The dry etching apparatus having a high-density plasma source may be, for example, an inductively coupled plasma (ICP) etching apparatus. Alternatively, a capacitively coupled plasma (CCP) etching apparatus having parallel-plate electrodes may be used. The capacitively coupled plasma etching apparatus having parallel-plate electrodes may be configured to apply a high-frequency voltage to one of the parallel-plate electrodes, or to apply a plurality of different high-frequency voltages to one of the parallel-plate electrodes, or to apply a high-frequency voltage of the same frequency to each of the parallel-plate electrodes, or to apply high-frequency voltages of different frequencies to each of the parallel-plate electrodes.

[0405] Furthermore, when dry etching is performed, by-products and the like produced by the dry etching may be deposited on the upper surface and side surfaces of insulating layer 127a, etc. Therefore, components contained in the etching gas, components contained in inorganic insulating film 125f, and components contained in sacrificial layers 158R, 158G, and 158B may be contained in insulating layer 127 after the display device is completed.

[0406] Furthermore, it is preferable to perform the first etching process by wet etching. Using wet etching can reduce damage to the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B compared to using dry etching. For example, wet etching can be performed using an alkaline solution. For example, TMAH, an alkaline solution, can be used for wet etching of an aluminum oxide film. In this case, wet etching can be performed by a puddle method. Note that, if the inorganic insulating film 125f is formed using the same material as the sacrificial layers 158R, 158G, and 158B, the above-mentioned etching process can be performed all at once, which is preferable.

[0407] In the first etching process, the sacrificial layers 158R, 158G, and 158B are not completely removed, and the etching process is stopped when the film thicknesses of the sacrificial layers 158R, 158G, and 158B are reduced. In this manner, by leaving the sacrificial layers 158R, 158G, and 158B on the organic compound layers 103R, 103G, and 103B, respectively, it is possible to prevent the organic compound layers 103R, 103G, and 103B from being damaged in subsequent processes.

[0408] Next, the entire substrate is exposed to visible light or ultraviolet light, and the insulating layer 127a is preferably irradiated with the energy density of 0 mJ / cm. 2 Larger, 800mJ / cm 2 It is preferable that the dose is 0 mJ / cm or less. 2 Larger, 500mJ / cm 2 It is more preferable to perform the following. By performing such exposure after development, the transparency of the insulating layer 127a can be improved in some cases. Furthermore, the substrate temperature required for heat treatment to transform the insulating layer 127a into a tapered shape in a later step can be reduced in some cases.

[0409] Here, the presence of an oxygen barrier insulating layer (e.g., an aluminum oxide film) as the sacrificial layers 158R, 158G, and 158B can reduce oxygen diffusion into the organic compound layers 103R, 103G, and 103B. When the organic compound layers are irradiated with light (visible light or ultraviolet light), the organic compounds contained in the organic compound layers become excited, which may promote a reaction with oxygen contained in the atmosphere. More specifically, when light (visible light or ultraviolet light) is irradiated onto an organic compound layer in an oxygen-containing atmosphere, oxygen may bond to the organic compounds contained in the organic compound layer. By providing the sacrificial layers 158R, 158G, and 158B on the island-shaped organic compound layers, it is possible to reduce oxygen from the atmosphere bonding to the organic compounds contained in the organic compound layers.

[0410] Next, heat treatment (also referred to as post-baking) is performed. By performing the heat treatment, the insulating layer 127a can be transformed into the insulating layer 127 having tapered side surfaces (FIG. 11C). The heat treatment is performed at a temperature lower than the upper temperature limit of the organic compound layer. The heat treatment can be performed at a substrate temperature of 50° C. to 200° C., preferably 60° C. to 150° C., more preferably 70° C. to 130° C. The heating atmosphere may be an air atmosphere or an inert gas atmosphere. The heating atmosphere may be an atmospheric pressure atmosphere or a reduced-pressure atmosphere. The substrate temperature in this heat treatment is preferably higher than that in the heat treatment (pre-baking) performed after the formation of the insulating film 127f. This can improve adhesion between the insulating layer 127 and the inorganic insulating layer 125 and also improve the corrosion resistance of the insulating layer 127.

[0411] By not completely removing the sacrificial layers 158R, 158G, and 158B in the first etching process and leaving the sacrificial layers 158R, 158G, and 158B in a thinner state, the organic compound layers 103R, 103G, and 103B can be prevented from being damaged and deteriorated in the heat treatment, thereby improving the reliability of the light-emitting device.

[0412] Depending on the material of the insulating layer 127 and the temperature, time, and atmosphere of post-baking, a concave curved shape may be formed on the side surface of the insulating layer 127. For example, the higher the temperature or the longer the post-baking time, the more likely the shape of the insulating layer 127 is to change, and a concave curved shape may be formed.

[0413] 12(A), an etching process is performed using the insulating layer 127 as a mask to remove portions of the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B. Note that a portion of the inorganic insulating layer 125 may also be removed. As a result, openings are formed in the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B, respectively, and the upper surfaces of the organic compound layer 103R, the organic compound layer 103G, the organic compound layer 103B, and the conductive layer 152C are exposed. Note that, hereinafter, the etching process using the insulating layer 127 as a mask may be referred to as a second etching process.

[0414] The end of the inorganic insulating layer 125 is covered with the insulating layer 127. Also, Fig. 12(A) shows an example in which part of the end of the sacrificial layer 158G (specifically, the tapered portion formed by the first etching process) is covered with the insulating layer 127, and the tapered portion formed by the second etching process is exposed.

[0415] If the inorganic insulating layer 125 and the sacrificial layer are etched together after post-baking without the first etching process, side etching may cause the inorganic insulating layer 125 and the sacrificial layer below the edge of the insulating layer 127 to disappear, forming a cavity. Such a cavity may cause unevenness on the surface on which the common electrode 155 is formed, making the common electrode 155 prone to step discontinuities. Even if the inorganic insulating layer 125 and the sacrificial layer are side-etched in the first etching process, post-baking can subsequently fill the cavity with the insulating layer 127. The second etching process then etches the thinner sacrificial layer, reducing the amount of side etching and making it less likely for a cavity to form. Even if a cavity does form, it can be extremely small. This allows for a flatter surface on which the common electrode 155 is formed.

[0416] The insulating layer 127 may cover the entire end of the sacrificial layer 158G. For example, the end of the insulating layer 127 may droop and cover the end of the sacrificial layer 158G. Furthermore, for example, the end of the insulating layer 127 may contact the upper surface of at least one of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B. As described above, if the developed insulating layer 127a is not exposed to light, the shape of the insulating layer 127 may be easily deformed.

[0417] The second etching process is performed by wet etching. By using the wet etching method, damage to the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B can be reduced compared to when using the dry etching method. The wet etching can be performed using an alkaline solution such as TMAH.

[0418] On the other hand, when the second etching process is performed using a wet etching method, if gaps are present between the organic compound layer 103 and the sacrificial layer 158, between the organic compound layer 103 and the inorganic insulating layer 125, or at the interface between the organic compound layer 103 and the insulating layer 175 due to, for example, adhesion issues between the organic compound layer 103 and other layers, the chemical solution used in the second etching process may penetrate into these gaps and come into contact with the pixel electrodes. If the chemical solution comes into contact with both the conductive layer 151 and the conductive layer 152, the conductive layer with the lower natural potential may corrode due to galvanic corrosion. For example, if aluminum is used for the conductive layer 151 and indium tin oxide is used for the conductive layer 152, the conductive layer 152 may corrode. As a result, the yield of the display device may decrease. Furthermore, the reliability of the display device may also decrease.

[0419] As described above, by forming the insulating layer 156 so as to cover the side surfaces of the conductive layer 151 and the conductive layer 152, it is possible to prevent the inorganic insulating layer 125 from being broken, and therefore it is possible to prevent the chemical solution from coming into contact with the underlying structure such as the conductive layer 151 during the second etching process, for example, thereby preventing corrosion of the pixel electrodes.

[0420] As described above, by providing the insulating layer 127, the inorganic insulating layer 125, the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B, it is possible to prevent connection defects caused by disconnected portions of the common electrode 155 between the light-emitting devices and an increase in electrical resistance caused by locally thin portions of the common electrode 155. As a result, the display quality of the display device of one embodiment of the present invention can be improved.

[0421] Furthermore, after exposing portions of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B, a further heat treatment is performed. This heat treatment can remove water contained in each organic compound layer, water adsorbed to the surface of each organic compound layer, and the like. This heat treatment may also change the shape of the insulating layer 127. Specifically, the insulating layer 127 may extend to cover at least one of the ends of the inorganic insulating layer 125, the ends of the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B, and the top surfaces of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B.

[0422] If the heat treatment temperature is too low, water contained in each organic compound layer and water adsorbed on the surface of each organic compound layer cannot be sufficiently removed. Furthermore, if the heat treatment temperature is too high, the organic compound layer 103 may be deteriorated and the shape of the insulating layer 127 may be excessively changed. Therefore, the heat treatment is preferably performed at a temperature higher than the temperature at which water desorbs from the organic compound layer 103 but lower than the glass transition temperature of the organic compound contained in the organic compound layer 103, and more preferably lower than the glass transition temperature of the organic compound contained on the upper surface of the organic compound layer 103. Specifically, the heat treatment is preferably performed at a substrate temperature of 80°C to 130°C, preferably 90°C to 120°C, more preferably 100°C to 120°C, and even more preferably 100°C to 110°C. The heating atmosphere may be an air atmosphere or an inert gas atmosphere. The heating atmosphere may be an atmospheric pressure atmosphere or a reduced pressure atmosphere. However, a reduced pressure atmosphere is preferred to prevent re-adsorption of water desorbed from the organic compound layer 103.

[0423] This heat treatment can sufficiently remove water contained in each organic compound layer and water adsorbed on the surface of each organic compound layer without causing deterioration of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B, or excessive change in the shape of the insulating layer 127. This can prevent deterioration in the characteristics of the light-emitting device.

[0424] 12(B), the common layer 104 and the common electrode 155 are formed on the organic compound layer 103R, the organic compound layer 103G, the organic compound layer 103B, the conductive layer 152C, and the insulating layer 127. The common layer 104 and the common electrode 155 can be formed by a method such as sputtering or vacuum deposition. The common layer 104 may be formed by deposition, and the common electrode 155 may be formed by sputtering.

[0425] 12(C), a protective layer 135 is formed on the common electrode 155. The protective layer 135 can be formed by a method such as vacuum deposition, sputtering, CVD, or ALD.

[0426] Subsequently, the substrate 120 is attached over the protective layer 135 using the resin layer 122, whereby a display device can be manufactured. As described above, in the method for manufacturing a display device of one embodiment of the present invention, the insulating layer 156 is provided on the side surfaces of the conductive layer 151 and the conductive layer 152. This can increase the yield of the display device and suppress the occurrence of defects.

[0427] As described above, in the manufacturing method of a display device according to one embodiment of the present invention, the island-shaped organic compound layers 103R, 103G, and 103B are formed by forming films over the entire surface and then processing them, rather than using a fine metal mask. This allows the island-shaped layers to be formed with uniform thicknesses. This allows a high-resolution display device or a display device with a high aperture ratio to be realized. Furthermore, even when the resolution or aperture ratio is high and the distance between subpixels is extremely short, the organic compound layers 103R, 103G, and 103B can be prevented from contacting each other in adjacent subpixels. Therefore, leakage current between subpixels can be suppressed. This prevents crosstalk and realizes a display device with extremely high contrast. Furthermore, a display device with excellent characteristics can be provided, even in a display device including tandem light-emitting devices fabricated by lithography.

[0428] The structure of this embodiment can be used in appropriate combination with structures of other embodiments.

[0429] (Fourth embodiment) In this embodiment, a light-emitting device of one embodiment of the present invention will be described with reference to FIGS. 13A to 13G and 14A to 14I.

[0430] [Pixel layout] In this embodiment, pixel layouts different from that shown in Fig. 5 will be mainly described. There are no particular limitations on the arrangement of sub-pixels, and various methods can be applied. Examples of sub-pixel arrangements include a stripe arrangement, an S-stripe arrangement, a matrix arrangement, a delta arrangement, a Bayer arrangement, and a pentile arrangement.

[0431] The top shape of the sub-pixels shown in the drawings in this embodiment mode corresponds to the top shape of the light-emitting region.

[0432] The top surface shape of the subpixel may be, for example, a triangle, a quadrangle (including a rectangle and a square), a polygon such as a pentagon, a polygon with rounded corners, an ellipse, or a circle.

[0433] Furthermore, the layout of the circuits constituting the sub-pixels is not limited to the range of the sub-pixels shown in the drawings, and may be arranged outside of the range.

[0434] An S-stripe arrangement is applied to the pixel 178 shown in Fig. 13(A). The pixel 178 shown in Fig. 13(A) is composed of three subpixels: a subpixel 110R, a subpixel 110G, and a subpixel 110B.

[0435] The pixel 178 shown in FIG. 13B includes a subpixel 110R having a generally trapezoidal or triangular top surface shape with rounded corners, a subpixel 110G having a generally trapezoidal or triangular top surface shape with rounded corners, and a subpixel 110B having a generally rectangular or hexagonal top surface shape with rounded corners. The subpixel 110R has a larger light-emitting area than the subpixel 110G. Thus, the shape and size of each subpixel can be determined independently. For example, the more reliable the light-emitting device, the smaller the size of the subpixel.

[0436] The Pentile arrangement is applied to the pixels 124a and 124b shown in Fig. 13(C). Fig. 13(C) shows an example in which the pixel 124a having the subpixel 110R and the subpixel 110G and the pixel 124b having the subpixel 110G and the subpixel 110B are arranged alternately.

[0437] 13(D) to 13(F) are arranged in a delta configuration. Pixel 124a has two subpixels (subpixel 110R and subpixel 110G) in the top row (first row) and one subpixel (subpixel 110B) in the bottom row (second row). Pixel 124b has one subpixel (subpixel 110B) in the top row (first row) and two subpixels (subpixel 110R and subpixel 110G) in the bottom row (second row).

[0438] Figure 13(D) is an example in which each sub-pixel has an approximately rectangular top surface shape with rounded corners, Figure 13(E) is an example in which each sub-pixel has a circular top surface shape, and Figure 13(F) is an example in which each sub-pixel has an approximately hexagonal top surface shape with rounded corners.

[0439] In Fig. 13(F), each subpixel is arranged inside a densely arranged hexagonal region. Each subpixel is arranged so that it is surrounded by six other subpixels when focusing on one subpixel. Furthermore, subpixels that emit light of the same color are arranged so that they are not adjacent to each other. For example, when focusing on subpixel 110R, three subpixels 110G and three subpixels 110B are arranged alternately to surround it.

[0440] 13G shows an example in which subpixels of each color are arranged in a zigzag pattern. Specifically, when viewed from above, the positions of the upper sides of two subpixels aligned in the row direction (for example, subpixels 110R and 110G, or subpixels 110G and 110B) are misaligned.

[0441] 13(A) to 13(G), it is preferable that the subpixel 110R is the subpixel R that emits red light, the subpixel 110G is the subpixel G that emits green light, and the subpixel 110B is the subpixel B that emits blue light. Note that the configuration of the subpixels is not limited to this, and the colors that the subpixels emit and their arrangement order can be determined appropriately. For example, the subpixel 110G may be the subpixel R that emits red light, and the subpixel 110R may be the subpixel G that emits green light.

[0442] In photolithography, the finer the pattern to be processed, the more significant the effect of light diffraction becomes. This impairs the fidelity of the photomask pattern when it is transferred by exposure, making it difficult to process the resist mask into the desired shape. Therefore, even if the photomask pattern is rectangular, a pattern with rounded corners is likely to be formed. As a result, the top surface shape of the subpixel may become a polygon with rounded corners, an ellipse, a circle, or the like.

[0443] Furthermore, in a method for manufacturing a light-emitting device according to one embodiment of the present invention, an organic compound layer is processed into an island shape using a resist mask. The resist film formed on the organic compound layer needs to be cured at a temperature lower than the heat resistance temperature of the organic compound layer. Therefore, depending on the heat resistance temperature of the material for the organic compound layer and the curing temperature of the resist material, the resist film may not be cured sufficiently. A resist film that is not cured sufficiently may have a shape that is different from the desired shape during processing. As a result, the top surface shape of the organic compound layer may be a polygon with rounded corners, an ellipse, a circle, or the like. For example, when a resist mask with a square top surface shape is formed, a resist mask with a circular top surface shape may be formed, resulting in a circular top surface shape of the organic compound layer.

[0444] In order to form the top surface of the organic compound layer into a desired shape, a technique for correcting the mask pattern in advance (OPC (Optical Proximity Correction) technique) may be used so that the design pattern and the transfer pattern coincide with each other. Specifically, in the OPC technique, a correction pattern is added to, for example, the corners of the figure on the mask pattern.

[0445] As shown in FIGS. 14A to 14I, a pixel can have four types of subpixels.

[0446] The pixels 178 shown in FIGS. 14(A) to 14(C) are arranged in a stripe pattern.

[0447] Figure 14(A) is an example in which each subpixel has a rectangular top surface shape, Figure 14(B) is an example in which each subpixel has a top surface shape that is a combination of two semicircles and a rectangle, and Figure 14(C) is an example in which each subpixel has an elliptical top surface shape.

[0448] The pixels 178 shown in FIGS. 14(D) to 14(F) are arranged in a matrix.

[0449] Figure 14(D) is an example in which each sub-pixel has a square top surface shape, Figure 14(E) is an example in which each sub-pixel has an approximately square top surface shape with rounded corners, and Figure 14(F) is an example in which each sub-pixel has a circular top surface shape.

[0450] 14(G) and 14(H) show an example in which one pixel 178 is configured in two rows and three columns.

[0451] 14(G) has three subpixels (subpixel 110R, subpixel 110G, and subpixel 110B) in the top row (first row) and one subpixel (subpixel 110W) in the bottom row (second row). In other words, pixel 178 has subpixel 110R in the left column (first column), subpixel 110G in the center column (second column), subpixel 110B in the right column (third column), and subpixel 110W across these three columns.

[0452] The pixel 178 shown in FIG. 14(H) has three subpixels (subpixel 110R, subpixel 110G, and subpixel 110B) in the top row (first row) and three subpixels 110W in the bottom row (second row). In other words, the pixel 178 has subpixel 110R and subpixel 110W in the left column (first column), subpixel 110G and subpixel 110W in the center column (second column), and subpixel 110B and subpixel 110W in the right column (third column). By aligning the subpixels in the top row and bottom row as shown in FIG. 14(H), it becomes possible to efficiently remove dust that may occur during the manufacturing process, for example. Therefore, a light-emitting device with high display quality can be provided.

[0453] In the pixel 178 shown in FIGS. 14(G) and 14(H), the subpixels 110R, 110G, and 110B are laid out in a stripe arrangement, which can improve the display quality.

[0454] FIG. 14(I) shows an example in which one pixel 178 is configured in three rows and two columns.

[0455] 14(I) has subpixel 110R in the top row (first row), subpixel 110G in the middle row (second row), subpixel 110B across the first and second rows, and one subpixel (subpixel 110W) in the bottom row (third row). In other words, pixel 178 has subpixel 110R and subpixel 110G in the left column (first column), subpixel 110B in the right column (second column), and subpixel 110W across these two columns.

[0456] In the pixel 178 shown in FIG. 14(I), the layout of the subpixels 110R, 110G, and 110B is a so-called S-stripe arrangement, which can improve the display quality.

[0457] 14A to 14I includes four subpixels: subpixel 110R, subpixel 110G, subpixel 110B, and subpixel 110W. For example, the subpixel 110R may be a subpixel that emits red light, the subpixel 110G may be a subpixel that emits green light, the subpixel 110B may be a subpixel that emits blue light, and the subpixel 110W may be a subpixel that emits white light. Note that at least one of the subpixels 110R, 110G, 110B, and 110W may be a subpixel that emits cyan light, a subpixel that emits magenta light, a subpixel that emits yellow light, or a subpixel that emits near-infrared light.

[0458] As described above, in the light-emitting device of one embodiment of the present invention, various layouts can be applied to pixels each including a subpixel having a light-emitting device.

[0459] This embodiment mode can be combined with other embodiment modes or examples as appropriate. In addition, in this specification, when multiple configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0460] (Embodiment 5) In this embodiment, a light-emitting device according to one embodiment of the present invention will be described.

[0461] The light emitting device of the present embodiment can be a high-definition light emitting device, and therefore can be used for the display unit of a wristwatch-type or bracelet-type information terminal (wearable device), a head-mounted display (HMD) or other VR device, and a head-mounted wearable device such as a glasses-type AR device.

[0462] The light-emitting device of this embodiment can be a high-resolution light-emitting device or a large-sized light-emitting device. Therefore, the light-emitting device of this embodiment can be used in the display portion of electronic devices having relatively large screens, such as television sets, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and sound reproducing devices.

[0463] [Display module] 15A shows a perspective view of a display module 280. The display module 280 includes a light-emitting device 100A and an FPC 290. Note that the light-emitting device included in the display module 280 is not limited to the light-emitting device 100A, and may be any of light-emitting devices 100B to 100F described below.

[0464] The display module 280 has a substrate 291 and a substrate 292. The display module 280 has a display unit 281. The display unit 281 is a region that displays an image in the display module 280, and is a region where light from each pixel provided in a pixel unit 284 (described later) can be viewed.

[0465] 15(B) is a perspective view schematically showing the configuration on the substrate 291 side. A circuit portion 282, a pixel circuit portion 283 on the circuit portion 282, and a pixel portion 284 on the pixel circuit portion 283 are stacked on the substrate 291. A terminal portion 285 for connecting to an FPC 290 is provided in a portion of the substrate 291 that does not overlap with the pixel portion 284. The terminal portion 285 and the circuit portion 282 are electrically connected by a wiring portion 286 composed of a plurality of wirings.

[0466] The pixel section 284 has a plurality of periodically arranged pixels 284a. An enlarged view of one pixel 284a is shown on the right side of Fig. 15(B). The various configurations described in the previous embodiments can be applied to the pixel 284a. Fig. 15(B) shows an example in which the pixel 284a has the same configuration as the pixel 178 shown in Fig. 5.

[0467] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0468] One pixel circuit 283a is a circuit that controls the driving of multiple elements included in one pixel 284a. One pixel circuit 283a can be configured to have three circuits that control the light emission of one light-emitting device. For example, the pixel circuit 283a can be configured to have at least one selection transistor, one current control transistor (drive transistor), and a capacitor for each light-emitting device. In this case, a gate signal is input to the gate of the selection transistor, and a video signal is input to the source or drain. This realizes an active matrix light-emitting device.

[0469] The circuit portion 282 includes a circuit for driving each pixel circuit 283a of the pixel circuit portion 283. For example, it is preferable that the circuit portion 282 includes one or both of a gate line driver circuit and a source line driver circuit. In addition, the circuit portion 282 may include at least one of an arithmetic circuit, a memory circuit, a power supply circuit, and the like.

[0470] The FPC 290 functions as wiring for supplying a video signal, a power supply potential, or the like from the outside to the circuit section 282. An IC may be mounted on the FPC 290.

[0471] The display module 280 can be configured such that one or both of the pixel circuit unit 283 and the circuit unit 282 are stacked below the pixel unit 284, thereby enabling the aperture ratio (effective display area ratio) of the display unit 281 to be extremely high. For example, the aperture ratio of the display unit 281 can be set to 40% or more and less than 100%, preferably 50% or more and 95% or less, and more preferably 60% or more and 95% or less. Furthermore, the pixels 284a can be arranged at an extremely high density, enabling the resolution of the display unit 281 to be extremely high. For example, it is preferable that the pixels 284a are arranged in the display unit 281 at a resolution of 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and 20000 ppi or less, or 30000 ppi or less.

[0472] Such a display module 280 has extremely high resolution and can therefore be suitably used in VR devices such as HMDs or eyeglass-type AR devices. For example, even in a configuration in which the display unit of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display unit 281, so that even when the display unit is enlarged with lenses, the pixels are not visible, allowing for a highly immersive display. Furthermore, the display module 280 is not limited to this, and can be suitably used in electronic devices having relatively small display units. For example, it can be suitably used in the display unit of a wearable electronic device such as a wristwatch.

[0473] [Light-emitting device 100A] The light emitting device 100A shown in FIG. 16A includes a substrate 301, a light emitting device 130R, a light emitting device 130G, a light emitting device 130B, a capacitor 240, and a transistor 310.

[0474] The substrate 301 corresponds to the substrate 291 in FIGS. 15A and 15B. The transistor 310 is a transistor having a channel formation region in the substrate 301. The substrate 301 can be, for example, a semiconductor substrate such as a single crystal silicon substrate. The transistor 310 includes a part of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region in which the substrate 301 is doped with impurities and functions as a source or drain. The insulating layer 314 is provided to cover a side surface of the conductive layer 311.

[0475] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301 .

[0476] In addition, an insulating layer 261 is provided to cover the transistor 310 , and a capacitor 240 is provided on the insulating layer 261 .

[0477] Capacitor 240 has conductive layer 241, conductive layer 245, and insulating layer 243 located therebetween. Conductive layer 241 functions as one electrode of capacitor 240, conductive layer 245 functions as the other electrode of capacitor 240, and insulating layer 243 functions as a dielectric of capacitor 240.

[0478] The conductive layer 241 is provided over the insulating layer 261 and is buried in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source and drain of the transistor 310 by a plug 271 buried in the insulating layer 261. The insulating layer 243 is provided to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping with the conductive layer 241 with the insulating layer 243 interposed therebetween.

[0479] An insulating layer 255 is provided to cover the capacitor 240, an insulating layer 174 is provided on the insulating layer 255, and an insulating layer 175 is provided on the insulating layer 174. The light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B are provided on the insulating layer 175. FIG. 16A shows an example in which the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B have the layered structure shown in FIG. 1A. An insulator is provided in the region between adjacent light-emitting devices. For example, in FIG. 16A, an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 are provided in this region.

[0480] An insulating layer 156R is provided to cover the side surfaces of the conductive layer 151R and the conductive layer 152R of the light-emitting device 130R, an insulating layer 156G is provided to cover the side surfaces of the conductive layer 151G and the conductive layer 152G of the light-emitting device 130G, and an insulating layer 156B is provided to cover the side surfaces of the conductive layer 151B and the conductive layer 152B of the light-emitting device 130B. Furthermore, a sacrificial layer 158R is located on the organic compound layer 103R of the light-emitting device 130R, a sacrificial layer 158G is located on the organic compound layer 103G of the light-emitting device 130G, and a sacrificial layer 158B is located on the organic compound layer 103B of the light-emitting device 130B.

[0481] The conductive layer 151R, the conductive layer 151G, and the conductive layer 151B are electrically connected to one of the source or drain of the transistor 310 via an insulating layer 243, an insulating layer 255, an insulating layer 174, a plug 256 embedded in the insulating layer 175, a conductive layer 241 embedded in the insulating layer 254, and a plug 271 embedded in the insulating layer 261. The height of the top surface of the insulating layer 175 and the height of the top surface of the plug 256 are the same or approximately the same. Various conductive materials can be used for the plug.

[0482] Furthermore, a protective layer 135 is provided on the light-emitting devices 130R, 130G, and 130B. A substrate 120 is bonded to the protective layer 135 via a resin layer 122. For details of the components from the light-emitting devices 130 to the substrate 120, refer to embodiment 3. The substrate 120 corresponds to the substrate 292 in FIG. 15(A).

[0483] Fig. 16(B) is a modified example of the light-emitting device 100A shown in Fig. 16(A). The light-emitting device shown in Fig. 16(B) has a colored layer 136R, a colored layer 136G, and a colored layer 136B, and the light-emitting device 130 has an area that overlaps with one of the colored layers 136R, 136G, and 136B. In the light-emitting device shown in Fig. 16(B), the light-emitting device 130 can emit, for example, white light. Furthermore, for example, the colored layer 136R can transmit red light, the colored layer 136G can transmit green light, and the colored layer 136B can transmit blue light.

[0484] [Light-emitting device 100B] FIG. 17 shows a perspective view of the light emitting device 100B, and FIG. 18(A) shows a cross-sectional view of the light emitting device 100B.

[0485] Light emitting device 100B has a configuration in which substrate 352 and substrate 351 are bonded together. In Fig. 17, substrate 352 is clearly indicated by a dashed line.

[0486] The light emitting device 100B has a pixel portion 177, a connection portion 140, a circuit 356, wiring 355, etc. Fig. 17 shows an example in which an IC (integrated circuit) 354 and an FPC 353 are mounted on the light emitting device 100B. Therefore, the configuration shown in Fig. 17 can also be called a display module having the light emitting device 100B, the IC, and the FPC. Here, a light emitting device having a connector such as an FPC attached to a substrate, or a light emitting device having an IC mounted on the substrate, is called a display module.

[0487] The connection portion 140 is provided outside the pixel portion 177. The connection portion 140 can be provided along one side or multiple sides of the pixel portion 177. There may be one or multiple connection portions 140. FIG. 17 shows an example in which the connection portion 140 is provided so as to surround the four sides of the pixel portion 177. The connection portion 140 electrically connects the common electrode of the light-emitting device and the conductive layer, and can supply a potential to the common electrode.

[0488] The circuit 356 can be, for example, a scanning line driver circuit.

[0489] The wiring 355 has a function of supplying signals and power to the pixel portion 177 and the circuit 356. The signals and power are input to the wiring 355 from the outside via the FPC 353 or from the IC 354.

[0490] 17 shows an example in which an IC 354 is provided on a substrate 351 by a COG (Chip on Glass) method or a COF (Chip on Film) method. The IC 354 may be, for example, an IC having a scanning line driver circuit or a signal line driver circuit. Note that the light-emitting device 100B and the display module may not necessarily include an IC. Alternatively, the IC may be mounted on an FPC by, for example, a COF method.

[0491] Figure 18(A) shows an example of a cross section of the light-emitting device 100B, where a portion of the region including the FPC 353, a portion of the circuit 356, a portion of the pixel portion 177, a portion of the connection portion 140, and a portion of the region including the end portion are cut.

[0492] The light-emitting device 100B shown in Figure 18(A) has, between a substrate 351 and a substrate 352, a transistor 201, a transistor 205, a light-emitting device 130R that emits red light, a light-emitting device 130G that emits green light, and a light-emitting device 130B that emits blue light, etc.

[0493] The light emitting devices 130R, 130G, and 130B each have the layered structure shown in Fig. 1A, except that the configuration of the pixel electrodes is different. For details of the light emitting devices, refer to the above embodiment.

[0494] Light-emitting device 130R includes conductive layer 224R, conductive layer 151R on conductive layer 224R, and conductive layer 152R on conductive layer 151R. Light-emitting device 130G includes conductive layer 224G, conductive layer 151G on conductive layer 224G, and conductive layer 152G on conductive layer 151G. Light-emitting device 130B includes conductive layer 224B, conductive layer 151B on conductive layer 224B, and conductive layer 152B on conductive layer 151B. Here, conductive layer 224R, conductive layer 151R, and conductive layer 152R may collectively be referred to as the pixel electrode of light-emitting device 130R, and conductive layer 151R and conductive layer 152R excluding conductive layer 224R may also be referred to as the pixel electrode of light-emitting device 130R. Similarly, conductive layer 224G, conductive layer 151G, and conductive layer 152G may be collectively referred to as the pixel electrode of light-emitting device 130G, and conductive layer 151G and conductive layer 152G excluding conductive layer 224G may be collectively referred to as the pixel electrode of light-emitting device 130G. Furthermore, conductive layer 224B, conductive layer 151B, and conductive layer 152B may be collectively referred to as the pixel electrode of light-emitting device 130B, and conductive layer 151B and conductive layer 152B excluding conductive layer 224B may be collectively referred to as the pixel electrode of light-emitting device 130B.

[0495] The conductive layer 224R is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214. An end of the conductive layer 151R is located outside an end of the conductive layer 224R. An insulating layer 156R is provided to have a region in contact with a side surface of the conductive layer 151R, and a conductive layer 152R is provided to cover the conductive layer 151R and the insulating layer 156R.

[0496] Conductive layer 224G, conductive layer 151G, conductive layer 152G, and insulating layer 156G in light-emitting device 130G, and conductive layer 224B, conductive layer 151B, conductive layer 152B, and insulating layer 156B in light-emitting device 130B are similar to conductive layer 224R, conductive layer 151R, conductive layer 152R, and insulating layer 156R in light-emitting device 130R, and therefore detailed description thereof will be omitted.

[0497] Recesses are formed in the conductive layers 224R, 224G, and 224B so as to cover the openings provided in the insulating layer 214. A layer 128 is buried in the recesses.

[0498] Layer 128 has the function of planarizing the recesses of conductive layer 224R, conductive layer 224G, and conductive layer 224B. Conductive layers 151R, 151G, and 151B, which are electrically connected to conductive layer 224R, conductive layer 224G, and conductive layer 224B, are provided on conductive layer 224R, conductive layer 224G, and conductive layer 224B and layer 128. Therefore, the regions overlapping with the recesses of conductive layer 224R, conductive layer 224G, and conductive layer 224B can also be used as light-emitting regions, thereby increasing the aperture ratio of the pixel.

[0499] The layer 128 may be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be used for the layer 128 as appropriate. In particular, the layer 128 is preferably formed using an insulating material, and is particularly preferably formed using an organic insulating material. For example, the organic insulating materials that can be used for the insulating layer 127 described above can be used for the layer 128.

[0500] A protective layer 135 is provided on the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B. The protective layer 135 and the substrate 352 are bonded via an adhesive layer 142. A light-shielding layer 157 is provided on the substrate 352. A solid sealing structure, a hollow sealing structure, or the like can be applied to seal the light-emitting device 130. In FIG. 18(A), the space between the substrate 352 and the substrate 351 is filled with the adhesive layer 142, and a solid sealing structure is applied. Alternatively, the space may be filled with an inert gas (nitrogen, argon, etc.), and a hollow sealing structure may be applied. In this case, the adhesive layer 142 may be provided so as not to overlap with the light-emitting device. Alternatively, the space may be filled with a resin different from the frame-shaped adhesive layer 142.

[0501] 18A shows an example in which the connection portion 140 has a conductive layer 224C obtained by processing the same conductive film as the conductive layers 224R, 224G, and 224B, a conductive layer 151C obtained by processing the same conductive film as the conductive layers 151R, 151G, and 151B, and a conductive layer 152C obtained by processing the same conductive film as the conductive layers 152R, 152G, and 152B. Also, FIG. 18A shows an example in which an insulating layer 156C is provided so as to have a region overlapping with a side surface of the conductive layer 151C.

[0502] The light emitting device 100B is a top-emission type. Light emitted by the light emitting device is emitted toward the substrate 352. The substrate 352 is preferably made of a material that is highly transparent to visible light. The pixel electrode contains a material that reflects visible light, and the counter electrode (common electrode 155) contains a material that transmits visible light.

[0503] The transistor 201 and the transistor 205 are both formed over a substrate 351. These transistors can be manufactured using the same material and the same process.

[0504] An insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are provided over the substrate 351 in this order. A part of the insulating layer 211 functions as a gate insulating layer for each transistor. A part of the insulating layer 213 functions as a gate insulating layer for each transistor. The insulating layer 215 is provided to cover the transistor. The insulating layer 214 is provided to cover the transistor and functions as a planarization layer. Note that the number of gate insulating layers and the number of insulating layers covering the transistors are not limited, and each may be a single layer or two or more layers.

[0505] It is preferable that at least one insulating layer covering the transistor is made of a material that is resistant to the diffusion of impurities such as water and hydrogen. This allows the insulating layer to function as a barrier layer. With this structure, it is possible to effectively prevent impurities from diffusing into the transistor from the outside, thereby improving the reliability of the light-emitting device.

[0506] It is preferable to use an inorganic insulating film for each of the insulating layers 211, 213, and 215. Examples of the inorganic insulating film that can be used include a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum oxide film, and an aluminum nitride film. Alternatively, a hafnium oxide film, an yttrium oxide film, a zirconium oxide film, a gallium oxide film, a tantalum oxide film, a magnesium oxide film, a lanthanum oxide film, a cerium oxide film, and a neodymium oxide film may also be used. Two or more of the above insulating films may be stacked.

[0507] An organic insulating layer is suitable for the insulating layer 214, which functions as a planarizing layer. Materials that can be used for the organic insulating layer include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimideamide resin, siloxane resin, benzocyclobutene-based resin, phenolic resin, and precursors of these resins. Alternatively, the insulating layer 214 may have a laminated structure of an organic insulating layer and an inorganic insulating layer. The outermost layer of the insulating layer 214 preferably functions as an etching protection layer. This prevents recesses from being formed in the insulating layer 214 during processing of the conductive layer 224R, the conductive layer 151R, the conductive layer 152R, or the like. Alternatively, recesses may be formed in the insulating layer 214 during processing of the conductive layer 224R, the conductive layer 151R, the conductive layer 152R, or the like.

[0508] The transistor 201 and the transistor 205 each include a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as a source and a drain, a semiconductor layer 231, an insulating layer 213 that functions as a gate insulating layer, and a conductive layer 223 that functions as a gate. Here, the same hatching pattern is applied to multiple layers obtained by processing the same conductive film. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

[0509] The structure of the transistor included in the light-emitting device of this embodiment is not particularly limited. For example, a planar transistor, a staggered transistor, an inverted staggered transistor, or the like can be used. Furthermore, either a top-gate transistor or a bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below a semiconductor layer in which a channel is formed.

[0510] The transistor 201 and the transistor 205 have a structure in which a semiconductor layer in which a channel is formed is sandwiched between two gates. The two gates may be connected and the same signal may be supplied to drive the transistor. Alternatively, the threshold voltage of the transistor may be controlled by applying a potential for controlling the threshold voltage to one of the two gates and a potential for driving to the other.

[0511] The crystallinity of a semiconductor material used for a transistor is not particularly limited, and any of an amorphous semiconductor and a crystalline semiconductor (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor having a crystalline region in part) may be used. The use of a crystalline semiconductor is preferable because it can suppress deterioration of transistor characteristics.

[0512] A semiconductor layer of the transistor preferably contains a metal oxide. That is, the light-emitting device of this embodiment preferably uses a transistor using a metal oxide in a channel formation region (hereinafter referred to...

Claims

1. An organometallic complex represented by General Formula (G1): 【Chemical 1】 (In the organometallic complex represented by the general formula (G1), R １ , R １３ and R １４ each independently represents a deuterium-containing alkyl group having 1 to 6 carbon atoms; R ２ ~R １２ each independently represents a deuterium-containing alkyl group having 1 to 6 carbon atoms or hydrogen (including deuterium), and R １５ ~R ２１ each independently represents hydrogen (including deuterium), and n represents 1 or 2.

2. An organometallic complex represented by general formula (G2): 【Chemistry 2】 (In the organometallic complex represented by the general formula (G2), R ２ ~R １２ each independently represents a deuterium-containing alkyl group having 1 to 6 carbon atoms or hydrogen (including deuterium), and R １５ ~R ２１ each independently represents hydrogen (including deuterium), and n represents 1 or 2.

3. 3. The organometallic complex according to claim 1 or 2, wherein n is 2.

4. In claim 1 or claim 2, An organometallic complex, wherein when a transition dipole moment involved in the luminescence of the organometallic complex is defined as vector B, vector B is 0.5 debye or more.

5. In claim 1 or claim 2, An organometallic complex comprising: a vector A connecting the two most distant atoms in the lowest excited triplet state of the organometallic complex; a plane A including the vector A, which, when the atomic group constituting the organometallic complex is projected perpendicularly onto the plane, encloses the projected atomic group of the organometallic complex with the largest area; a plane B perpendicular to the plane A and including the vector A; a transition dipole moment associated with the emission of the organometallic complex being defined as vector B; and an angle between the vector A and the vector B' obtained by projecting the vector B onto the plane B, which is 25° or less (provided that the direction of the vector A is determined so that the angle between the vector A and the vector B is 90° or less).

6. An organometallic complex represented by structural formula (100) or structural formula (101). 【Chemistry 3】

7. A light-emitting device using the organometallic complex according to any one of claims 1 to 6.

8. A light-emitting device containing an organometallic complex as a light-emitting material in a light-emitting layer, The organometallic complex has a first ligand and a second ligand, the first ligand has a benzene ring and a pyridine ring, the carbon atom at the 2-position of the pyridine ring is bonded to the benzene ring; the second ligand comprises a benzofuro[2,3-b]pyridine ring; A light-emitting device, wherein the molecular orientation parameter a of light emitted from said light-emitting device is 0.28 or less.

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