Mixed material

Abstract

To provide a novel mixed material with improved heat resistance.SOLUTION: The mixed material includes a first heteroaromatic compound and a second heteroaromatic compound, where the first heteroaromatic compound is represented by one of general formulas (G1) to (G6), provided that the second heteroaromatic compound is not represented by the same general formula as that of the first heteroaromatic compound.SELECTED DRAWING: None

Description

[Technical Field]

[0001] One aspect of the present invention relates to a mixed material applicable to light-emitting devices. It also relates to light-emitting devices, display modules, lighting modules, display devices, light-emitting devices, electronic devices, lighting devices, and electronic devices. However, one aspect of the present invention is not limited to the above-mentioned technical fields. The technical fields of one aspect of the invention disclosed herein relate to materials, methods, or methods of manufacture. Alternatively, one aspect of the present invention relates to processes, machines, manufactures, or compositions of matter. Therefore, more specifically, examples of the technical fields of one aspect of the present invention disclosed herein include semiconductor devices, display devices, light-emitting devices, lighting devices, memory devices, imaging devices, methods for driving them, or methods for manufacturing them. [Background technology]

[0002] The practical application of light-emitting devices (organic EL devices) that utilize electroluminescence (EL) using organic compounds is progressing. The basic structure of these light-emitting devices is an organic compound layer (EL layer) containing a light-emitting material sandwiched between a pair of electrodes. By applying a voltage to this device, carriers are injected, and by utilizing the recombination energy of these carriers, light emission can be obtained from the light-emitting material.

[0003] Because these light-emitting devices are self-emissive, using them as pixels in a display offers advantages over liquid crystal displays, such as higher visibility and the elimination of the need for a backlight, making them suitable as flat-panel display elements. Furthermore, displays using such light-emitting devices can be manufactured to be thin and lightweight, which is a significant advantage. Another characteristic is their extremely fast response speed.

[0004] Furthermore, since these light-emitting devices can form a light-emitting layer continuously in two dimensions, they can produce light in a planar manner. This is a feature that is difficult to obtain with point light sources such as incandescent bulbs and LEDs, or line light sources such as fluorescent lamps, and therefore has high value as a planar light source that can be applied to lighting and other applications.

[0005] While displays and lighting devices using light-emitting devices are suitable for various electronic devices, research and development are underway to find light-emitting devices with even better characteristics.

[0006] The organic compounds used in light-emitting devices significantly influence their characteristics. Therefore, it is crucial for improving the reliability of light-emitting devices that the properties of the organic compounds used are applicable to the temperature range required by the manufacturing process and application of the device. For this reason, research is underway to develop materials that suppress thermal morphological changes (Patent Document 1). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2017-75114 [Overview of the project] [Problems that the invention aims to solve]

[0008] One aspect of the present invention aims to provide a novel mixed material with improved heat resistance. Another aspect of the present invention aims to provide a novel light-emitting device with superior convenience, usefulness, or reliability. Yet another aspect of the present invention aims to provide a novel organic semiconductor device. Another aspect of the present invention aims to provide a novel light-emitting device with superior convenience, usefulness, or reliability. Another aspect of the present invention aims to provide a novel electronic device with superior convenience, usefulness, or reliability. Another aspect of the present invention aims to provide a novel lighting device with superior convenience, usefulness, or reliability.

[0009] Furthermore, one aspect of the present invention aims to provide a novel mixed material that can improve heat resistance during thin-film formation. Another aspect of the present invention aims to provide a light-emitting device with high heat resistance. Another aspect of the present invention aims to provide a light-emitting device with high heat resistance in the manufacturing process. Alternatively, another aspect of the present invention aims to provide a highly reliable light-emitting device. Another aspect of the present invention aims to provide an organic semiconductor device with high heat resistance. Another aspect of the present invention aims to provide an organic semiconductor device with high heat resistance in the manufacturing process. Alternatively, another aspect of the present invention aims to provide a highly reliable organic semiconductor device. Alternatively, one aspect of the present invention aims to provide a light-emitting device, organic semiconductor device, light-emitting apparatus, electronic device, display device, and electronic device with low power consumption. Alternatively, one aspect of the present invention aims to provide a light-emitting device, organic semiconductor device, light-emitting apparatus, electronic device, display device, and electronic device with low power consumption and high reliability.

[0010] Furthermore, the description of these problems does not preclude the existence of other problems. Moreover, one aspect of the present invention does not need to solve all of these problems. Other problems will naturally become apparent from the description in the specification, drawings, and claims, and it is possible to extract other problems from the description in the specification, drawings, and claims. [Means for solving the problem]

[0011] One aspect of the present invention is a mixed material having a plurality of heteroaromatic compounds, each of which has at least one heteroaromatic ring, and at least one of the plurality of heteroaromatic compounds having a fused ring structure represented by any one of general formulas (G1) to (G6).

[0012] [ka]

[0013] Note that in the above formula (G1), A 1 R represents any of the following: a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted benzonaphthothiophenyl group, a substituted or unsubstituted dinaphthothiophenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted benzonaphthofuranyl group, or a substituted or unsubstituted dinaphthofuranyl group. 11 ~R 19 Each of these independently represents either hydrogen, a C1 to C4 alkyl group, or a C6 to C13 substituted or unsubstituted aryl group, Ar 1 R represents an arylene group having 6 to 30 carbon atoms, and the arylene group may have substituents, and the substituents may be bonded to each other to form a ring. Also, in the above formula (G2), 51 ~R 58represents, independently of each other, any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms, or a substituted or unsubstituted heterocyclic ring having 1 to 6 carbon atoms. Further, in the above formula (G3), A 2 represents a substituent having 3 to 30 carbon atoms containing an aromatic ring or a heteroaromatic ring. Also, R 81 to R 87 each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms, and n is 2 or 3. Further, in the above formula (G4), R 101 and R 102 each independently represent hydrogen or a group having a total of 1 to 100 carbon atoms, and at least one of R 101 and R 102 has a substituent containing any one of a pyrrole ring structure, a furan ring structure, or a thiophene ring structure via a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenylene group. Further, in the above formula (G5), Ar 2 , Ar 7] 3 , Ar 4 , and Ar 5 each independently represent a substituted or unsubstituted aromatic hydrocarbon ring, and the substituent of the aromatic hydrocarbon ring is any one of an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, or a cyano group, and the number of carbon atoms forming the aromatic hydrocarbon ring is 6 to 25. Also, m and n are each 0 or 1. Also, R 103 and R 104 each independently represent hydrogen or a group having a total of 1 to 100 carbon atoms, and at least one of R 103 and R 104 has a substituent containing any one of a pyrrole ring structure, a furan ring structure, or a thiophene ring structure via a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenylene group. Further, in the above formula (G6), Ar 2 , Ar 3 , Ar 4, and Ar 5 Each of these independently represents a substituted or unsubstituted aromatic hydrocarbon ring, and the substituents of the aromatic hydrocarbon ring are one of the following: an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, or a cyano group, and the number of carbon atoms forming the aromatic hydrocarbon ring is 6 to 25. Also, m and n are 0 or 1, respectively. Also, R 105 and R 106 Each of these independently represents hydrogen or a group with a total of 1 to 100 carbon atoms, R 105 and R 106 At least one of the components has a substituent that includes a ring of any one of the following: a pyrrole ring structure, a furan ring structure, or a thiophene ring structure, via a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenylene group.

[0014] Another aspect of the present invention is a mixed material having a plurality of heteroaromatic compounds, each of which has at least one heteroaromatic ring, and at least one of the plurality of heteroaromatic compounds having a fused ring structure represented by any one of general formulas (G1-1) to (G6-1).

[0015] [ka]

[0016] In the above formula (G1-1), Z represents nitrogen, oxygen, or sulfur, and R 11 ~R 19 and R 21 ~R 28 Each of these independently represents either hydrogen, a C1 to C4 alkyl group, or a C6 to C13 substituted or unsubstituted aryl group, Ar 1 represents an arylene group having 6 to 30 carbon atoms. However, when Z represents nitrogen, Z may have hydrogen, an alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or Z may be Ar 1 It may be directly coupled to R21 ~R 28 One of the following is Ar 1 It may also form a bond with. Furthermore, the arylene group may have substituents, and these substituents may bond to each other to form a ring. Also, in the above formula (G2-1), R 51 ~R 58 Each of these independently represents one of the following: hydrogen, a C1 to C4 alkyl group, a C6 to C14 substituted or unsubstituted aryl group, a C1 to C15 substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted C1 to C6 heterocycle. Also, in the above formula (G3-1), A 2 R represents a substituent with 3 to 30 carbon atoms, containing a substituted or unsubstituted aromatic ring or a heteroaromatic ring. 81 represents hydrogen, an alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms. In addition, in the above formula (G4-1), Q represents oxygen or sulfur, and R 200 and R 201 Each of the following substituents represents one to four substituents, and each independently represents one of hydrogen, a C1 to C6 alkyl group, or a substituted or unsubstituted C6 to C13 aromatic hydrocarbon group, R 200 and R 201 If the values ​​are 2 to 4, they may be the same or different. Also, in the above formula (G5-1), Q represents oxygen or sulfur, and Ar 4 , and Ar 5 Each independently represents a substituted or unsubstituted aromatic hydrocarbon ring, and the substituents of the aromatic hydrocarbon ring are one of the following: an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, or a cyano group, and the number of carbon atoms forming the aromatic hydrocarbon ring is 6 to 30. Also, Ar 6 represents an arylene group having 6 to 13 carbon atoms, and the arylene group may have substituents, and the substituents may be bonded to each other to form a ring. Also, q is 0 or 1. Also, R 200 and R 201Each of the following substituents represents one to four atoms, and each independently represents one of hydrogen, a C1 to C6 alkyl group, or a substituted or unsubstituted C6 to C13 aromatic hydrocarbon group. In formula (G6-1), Q represents oxygen or sulfur, and Ar 4 , and Ar 5 Each independently represents a substituted or unsubstituted aromatic hydrocarbon ring, and the substituents of the aromatic hydrocarbon ring are one of the following: an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, or a cyano group, and the number of carbon atoms forming the aromatic hydrocarbon ring is 6 to 30. Also, Ar 6 represents an arylene group having 6 to 13 carbon atoms, and the arylene group may have substituents, and the substituents may be bonded to each other to form a ring. Also, q is 0 to 4. Also, R 200 and R 201 Each of these represents one to four substituents, and each independently represents one of the following: hydrogen, a C1 to C6 alkyl group, or a substituted or unsubstituted C6 to C13 aromatic hydrocarbon group.

[0017] Another aspect of the present invention is a mixed material having a plurality of heteroaromatic compounds, each of which is represented by one of the general formulas (G1) to (G6) and has a different molecular structure.

[0018] [ka]

[0019] Also, in the above formula (G1), A 1 R represents any of the following: a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted benzonaphthothiophenyl group, a substituted or unsubstituted dinaphthothiophenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted benzonaphthofuranyl group, or a substituted or unsubstituted dinaphthofuranyl group.11 ~R 19 Each of these independently represents either hydrogen, a C1 to C4 alkyl group, or a C6 to C13 substituted or unsubstituted aryl group, Ar 1 R represents an arylene group having 6 to 30 carbon atoms, and the arylene group may have substituents, and the substituents may be bonded to each other to form a ring. Also, in the above formula (G2), 51 ~R 58 Each of these independently represents one of the following: hydrogen, a C1 to C4 alkyl group, a C6 to C30 substituted or unsubstituted aryl group, a C1 to C30 substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted C1 to C6 heterocycle. Also, in the above formula (G3), A 2 R represents a substituent with 3 to 30 carbon atoms that contains an aromatic ring or a heteroaromatic ring. 81 ~R 87 Each of these independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms, and n is 2 or 3. Also, in the above formula (G4), R 101 and R 102 Each of these independently represents hydrogen or a group with a total of 1 to 100 carbon atoms, R 101 and R 102 At least one of the groups has a substituent that includes a ring of any one of the following: a pyrrole ring structure, a furan ring structure, or a thiophene ring structure, via a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenylene group. Also, in formula (G5) above, Ar 2 Ar 3 Ar 4 , and Ar 5 Each of these independently represents a substituted or unsubstituted aromatic hydrocarbon ring, and the substituents of the aromatic hydrocarbon ring are one of the following: an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, or a cyano group, and the number of carbon atoms forming the aromatic hydrocarbon ring is 6 to 25. Also, m and n are 0 or 1, respectively. Also, R 103 and R 104Each of these independently represents hydrogen or a group with a total of 1 to 100 carbon atoms, R 103 and R 104 At least one of the groups has a substituent that includes a ring of any one of the following: a pyrrole ring structure, a furan ring structure, or a thiophene ring structure, via a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenylene group. Also, in formula (G6) above, Ar 2 Ar 3 Ar 4 , and Ar 5 Each of these independently represents a substituted or unsubstituted aromatic hydrocarbon ring, and the substituents of the aromatic hydrocarbon ring are one of the following: an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, or a cyano group, and the number of carbon atoms forming the aromatic hydrocarbon ring is 6 to 25. Also, m and n are 0 or 1, respectively. Also, R 105 and R 106 Each of these independently represents hydrogen or a group with a total of 1 to 100 carbon atoms, R 105 and R 106 At least one of the components has a substituent that includes a ring of any one of the following: a pyrrole ring structure, a furan ring structure, or a thiophene ring structure, via a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenylene group.

[0020] Another aspect of the present invention is a mixed material having a plurality of heteroaromatic compounds, each of which is represented by one of the general formulas (G1-1) to (G6-1) and has a different molecular structure.

[0021] [ka]

[0022] In the above formula (G1-1), Z represents nitrogen, oxygen, or sulfur, and R 11 ~R 19 and R 21 ~R 28each independently represents either hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, and Ar 1 represents an arylene group having 6 to 30 carbon atoms. However, when Z represents nitrogen, Z has hydrogen, an alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or Z is directly bonded to Ar 1 and may be directly bonded, or R 21 ~R 28 any one of which may be a bond with Ar 1 The arylene group may have a substituent, and the substituents may be bonded to each other to form a ring. Also, in the above formula (G2-1), R 51 ~R 58 each independently represents either hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 14 carbon atoms, or a substituted or unsubstituted heteroaryl group having 1 to 15 carbon atoms, or a substituted or unsubstituted heterocyclic ring having 1 to 6 carbon atoms. Also, in the above formula (G3-1), A 2 represents a substituent having 3 to 30 carbon atoms including a substituted or unsubstituted aromatic ring or heteroaromatic ring. Also, R 81 represents either hydrogen, an alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms. Also, in the above formula (G4-1), Q represents oxygen or sulfur, and R 200 and R 201 each represents any one of the substituents from 1 to 4, and each independently represents either hydrogen, an alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms, and R 200 and R 201 may be the same or different when they are 2 to 4. Also, in the above formula (G5-1), Q represents oxygen or sulfur, Ar 4 , and Ar 5Each independently represents a substituted or unsubstituted aromatic hydrocarbon ring, and the substituents of the aromatic hydrocarbon ring are one of the following: an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, or a cyano group, and the number of carbon atoms forming the aromatic hydrocarbon ring is 6 to 30. Also, Ar 6 represents an arylene group having 6 to 13 carbon atoms, and the arylene group may have substituents, and the substituents may be bonded to each other to form a ring. Also, q is 0 or 1. Also, R 200 and R 201 Each of the following substituents represents one to four atoms, and each independently represents one of hydrogen, a C1 to C6 alkyl group, or a substituted or unsubstituted C6 to C13 aromatic hydrocarbon group. In formula (G6-1), Q represents oxygen or sulfur, and Ar 4 , and Ar 5 Each independently represents a substituted or unsubstituted aromatic hydrocarbon ring, and the substituents of the aromatic hydrocarbon ring are one of the following: an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, or a cyano group, and the number of carbon atoms forming the aromatic hydrocarbon ring is 6 to 30. Also, Ar 6 represents an arylene group having 6 to 13 carbon atoms, and the arylene group may have substituents, and the substituents may be bonded to each other to form a ring. Also, q is 0 to 4. Also, R 200 and R 201 Each of these represents one to four substituents, and each independently represents one of the following: hydrogen, a C1 to C6 alkyl group, or a substituted or unsubstituted C6 to C13 aromatic hydrocarbon group.

[0023] Another aspect of the present invention is a mixed material having a plurality of heteroaromatic compounds, each of which is represented by one of structural formulas (101) to (108) and has a different molecular structure.

[0024] [ka]

[0025] In each of the above configurations, the heteroaromatic ring has one of the following skeletons: pyridine, diazine, triazine, or polyazole.

[0026] In each of the above configurations, the condensed heteroaromatic ring is one of the following: quinoline ring, benzoquinoline ring, quinoxaline ring, dibenzoquinoxaline ring, quinazoline ring, benzoquinazoline ring, dibenzoquinazoline ring, phenanthroline ring, phlodiazine ring, or benzimidazole ring.

[0027] Furthermore, in addition to the light-emitting devices described above, devices having a layer containing an organic compound in contact with the electrodes (e.g., a cap layer) are also included in the scope of the present invention. In addition to light-emitting devices, light-emitting devices having transistors, substrates, etc. are also included in the scope of the invention. Moreover, electronic devices and lighting devices having these light-emitting devices and any of the following are also included in the scope of the invention:

[0028] Furthermore, one aspect of the present invention includes a light-emitting device having a light-emitting device, and further includes an illumination device having a light-emitting device. Accordingly, in this specification, a light-emitting device refers to an image display device or a light source (including an illumination device). In addition, modules to which connectors such as FPC (Flexible printed circuit) or TCP (Tape Carrier Package) are attached, modules to which a printed circuit board is provided at the end of a TCP, or modules to which an IC (Integrated Circuit) is directly mounted on the light-emitting device using the COG (Chip On Glass) method are all included as light-emitting devices.

[0029] In this specification, the terms "source" and "drain" of a transistor are interchangeable depending on the transistor's polarity and the potential applied to each terminal. Generally, in an n-channel transistor, the terminal to which a low potential is applied is called the source, and the terminal to which a high potential is applied is called the drain. Similarly, in a p-channel transistor, the terminal to which a low potential is applied is called the drain, and the terminal to which a high potential is applied is called the source. For convenience, this specification sometimes describes the connection relationships of a transistor assuming that the source and drain are fixed, but in reality, the terms "source" and "drain" are interchangeable according to the potential relationship described above.

[0030] In this specification, the source of a transistor refers to the source region, which is part of the semiconductor film that functions as the active layer, or the source electrode connected to the semiconductor film. Similarly, the drain of a transistor refers to the drain region, which is part of the semiconductor film, or the drain electrode connected to the semiconductor film. The gate refers to the gate electrode.

[0031] In this specification, a state in which transistors are connected in series means, for example, a state in which only one source or drain of the first transistor is connected to only one source or drain of the second transistor. A state in which transistors are connected in parallel means a state in which one source or drain of the first transistor is connected to one source or drain of the second transistor, and the other source or drain of the first transistor is connected to the other source or drain of the second transistor.

[0032] In this specification, "connection" means an electrical connection, corresponding to a state in which current, voltage, or potential can be supplied or transmitted. Therefore, a connected state does not necessarily refer to a direct connection, but also includes a state indirectly connected through circuit elements such as wiring, resistors, diodes, and transistors, so that current, voltage, or potential can be supplied or transmitted.

[0033] In this specification, even when components that appear independent in a circuit diagram are connected, in reality, a single conductive film may combine the functions of multiple components, for example, when a portion of the wiring functions as an electrode. In this specification, "connection" includes such cases where a single conductive film combines the functions of multiple components. [Effects of the Invention]

[0034] One aspect of the present invention can provide a novel mixed material with improved heat resistance. Another aspect of the present invention can provide a novel light-emitting device with superior convenience, usefulness, or reliability. Yet another aspect of the present invention can provide a novel organic semiconductor device. Another aspect of the present invention can provide a novel light-emitting device with superior convenience, usefulness, or reliability. Another aspect of the present invention can provide a novel electronic device with superior convenience, usefulness, or reliability. Another aspect of the present invention can provide a novel lighting device with superior convenience, usefulness, or reliability.

[0035] Furthermore, one aspect of the present invention can provide a novel mixed material that can improve heat resistance during thin-film formation. Furthermore, one aspect of the present invention can provide a light-emitting device with high heat resistance. Furthermore, one aspect of the present invention can provide a light-emitting device with high heat resistance in the manufacturing process. Alternatively, another aspect of the present invention can provide a highly reliable light-emitting device. Furthermore, one aspect of the present invention can provide an organic semiconductor device with high heat resistance. Furthermore, one aspect of the present invention can provide an organic semiconductor device with high heat resistance in the manufacturing process. Alternatively, another aspect of the present invention can provide a highly reliable organic semiconductor device. Alternatively, one aspect of the present invention can provide a light-emitting device, organic semiconductor device, light-emitting apparatus, electronic device, display device, and electronic device, each with low power consumption. Alternatively, one aspect of the present invention can provide a light-emitting device, organic semiconductor device, light-emitting apparatus, electronic device, display device, and electronic device, each with low power consumption and high reliability.

[0036] Furthermore, the description of these effects does not preclude the existence of other effects. Moreover, one aspect of the present invention does not necessarily have to possess all of these effects. Other effects will naturally become apparent from the description in the specification, drawings, and claims, and it is possible to extract other effects from the description in the specification, drawings, and claims. [Brief explanation of the drawing]

[0037] [Figure 1] Figures 1(A) to 1(E) illustrate the configuration of a light-emitting device according to an embodiment. [Figure 2] Figures 2(A) to 2(C) illustrate a light-emitting device according to an embodiment. [Figure 3] Figures 3(A) to 3(C) illustrate a method for manufacturing a light-emitting device according to an embodiment. [Figure 4] Figures 4(A) to 4(C) illustrate a method for manufacturing a light-emitting device according to an embodiment. [Figure 5] Figures 5(A) to 5(C) illustrate a method for manufacturing a light-emitting device according to an embodiment. [Figure 6] Figures 6(A) to 6(C) illustrate a method for manufacturing a light-emitting device according to an embodiment. [Figure 7] Figure 7 is a diagram illustrating a light-emitting device according to an embodiment. [Figure 8] Figures 8(A) and 8(B) illustrate a light-emitting device according to an embodiment. [Figure 9] Figures 9(A) and 9(B) illustrate a light-emitting device according to an embodiment. [Figure 10] Figures 10(A) and 10(B) illustrate a light-emitting device according to an embodiment. [Figure 11] Figures 11(A) and 11(B) illustrate a light-emitting device according to an embodiment. [Figure 12] Figures 12(A) to 12(E) illustrate the electronic device according to the embodiment. [Figure 13] Figures 13(A) to 13(E) illustrate the electronic device according to the embodiment. [Figure 14] Figures 14(A) and 14(B) illustrate an electronic device according to an embodiment. [Figure 15] Figures 15(A) and 15(B) illustrate the electronic device according to the embodiment. [Figure 16] Figure 16 is a diagram illustrating an electronic device according to an embodiment. [Figure 17] Figures 17(A) to 17(D) are photographs relating to the embodiment. [Figure 18] Figures 18(A) to 18(D) are photographs relating to the embodiment. [Figure 19] Figures 19(A) to 19(D) are photographs relating to the embodiment. [Figure 20] Figure 20 is a diagram illustrating the configuration of a light-emitting device according to an embodiment. [Figure 21]Figure 21 shows the luminance-current density characteristics of light-emitting device 1 and comparative light-emitting device 1. [Figure 22] Figure 22 shows the current efficiency-luminance characteristics of light-emitting device 1 and comparative light-emitting device 1. [Figure 23] Figure 23 shows the luminance-voltage characteristics of light-emitting device 1 and comparison light-emitting device 1. [Figure 24] Figure 24 shows the current-voltage characteristics of light-emitting device 1 and comparison light-emitting device 1. [Figure 25] Figure 25 shows the external quantum efficiency-luminance characteristics of light-emitting device 1 and comparative light-emitting device 1. [Figure 26] Figure 26 shows the emission spectra of light-emitting device 1 and comparison light-emitting device 1. [Figure 27] Figure 27 shows the reliability of light-emitting device 1 and comparison light-emitting device 1. [Figure 28] Figures 28(A) to 28(C) illustrate a display device according to an embodiment. [Modes for carrying out the invention]

[0038] The embodiments of the present invention will be described in detail below with reference to the drawings. However, it will be readily apparent to those skilled in the art that the present invention is not limited to the following description, and that its form and details can be modified in various ways without departing from the spirit and scope of the present invention. Accordingly, the present invention shall not be interpreted as being limited to the contents of the embodiments shown below.

[0039] (Embodiment 1) This embodiment describes a mixed material that is one aspect of the present invention. By using this mixed material, the heat resistance of thin films can be improved. In other words, it is a mixed material that can effectively suppress morphological changes caused by thinning.

[0040] One embodiment of the present invention is a mixed material comprising a plurality of heteroaromatic compounds, each heteroaromatic compound having at least one heteroaromatic ring. Furthermore, at least one of the plurality of heteroaromatic compounds is a fused heteroaromatic ring having a fused ring structure.

[0041] Furthermore, a heteroaromatic ring exhibits a ring structure having one of the following skeletons: pyridine, diazine, triazine, or polyazole. Note that heteroaromatic rings having a diazine skeleton include heteroaromatic rings having a pyrimidine skeleton, heteroaromatic rings having a pyrazine skeleton, and heteroaromatic rings having a pyridazine skeleton.

[0042] Furthermore, the above-mentioned heteroaromatic rings include fused heteroaromatic rings having a fused ring structure. Examples of fused heteroaromatic rings include quinoline rings, benzoquinoline rings, quinoxaline rings, dibenzoquinoxaline rings, quinazoline rings, benzoquinazoline rings, dibenzoquinazoline rings, phenanthroline rings, phlodiazine rings, and benzimidazole rings.

[0043] Furthermore, in another aspect of the present invention, the mixed material comprises a plurality of heteroaromatic compounds, each heteroaromatic compound having at least one condensed heteroaromatic ring.

[0044] Furthermore, it is preferable that the above-mentioned mixed material does not contain metal complexes. Examples of such metal complexes include alkali metal complexes and alkaline earth metal complexes, particularly alkali metal quinolinol complexes or alkaline earth metal quinolinol complexes.

[0045] Furthermore, in one aspect of the present invention, the mixed material comprises a plurality of heteroaromatic compounds, each of which has at least one heteroaromatic ring, and at least one of the heteroaromatic compounds has a fused ring structure represented by any one of general formulas (G1) to (G6). It should be noted that all of the plurality of heteroaromatic compounds may have a fused ring structure represented by any one of general formulas (G1) to (G6), in which case not only the molecular structure of each heteroaromatic compound but also the general formulas will differ.

[0046] [ka]

[0047] Note that in the above formula (G1), A 1 R represents any of the following: a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted benzonaphthothiophenyl group, a substituted or unsubstituted dinaphthothiophenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted benzonaphthofuranyl group, or a substituted or unsubstituted dinaphthofuranyl group. 11 ~R 19 Each of these independently represents either hydrogen, a C1 to C4 alkyl group, or a C6 to C13 substituted or unsubstituted aryl group, Ar 1 R represents an arylene group having 6 to 30 carbon atoms, and the arylene group may have substituents, and the substituents may be bonded to each other to form a ring. Also, in the above formula (G2), 51 ~R 58 Each of these independently represents one of the following: hydrogen, a C1 to C4 alkyl group, a C6 to C30 substituted or unsubstituted aryl group, a C1 to C30 substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted C1 to C6 heterocycle. Also, in the above formula (G3), A 2 R represents a substituent with 3 to 30 carbon atoms that contains an aromatic ring or a heteroaromatic ring. 81 ~R 87Each of these independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms, and n is 2 or 3. Also, in the above formula (G4), R 101 and R 102 Each of these independently represents hydrogen or a group with a total of 1 to 100 carbon atoms, R 101 and R 102 At least one of the groups has a substituent that includes a ring of any one of the following: a pyrrole ring structure, a furan ring structure, or a thiophene ring structure, via a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenylene group. Also, in formula (G5) above, Ar 2 Ar 3 Ar 4 , and Ar 5 Each of these independently represents a substituted or unsubstituted aromatic hydrocarbon ring, and the substituents of the aromatic hydrocarbon ring are one of the following: an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, or a cyano group, and the number of carbon atoms forming the aromatic hydrocarbon ring is 6 to 25. Also, m and n are 0 or 1, respectively. Also, R 103 and R 104 Each of these independently represents hydrogen or a group with a total of 1 to 100 carbon atoms, R 103 and R 104 At least one of the groups has a substituent that includes a ring of any one of the following: a pyrrole ring structure, a furan ring structure, or a thiophene ring structure, via a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenylene group. Also, in formula (G6) above, Ar 2 Ar 3 Ar 4 , and Ar 5Each of these independently represents a substituted or unsubstituted aromatic hydrocarbon ring, and the substituents of the aromatic hydrocarbon ring are one of the following: an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, or a cyano group, and the number of carbon atoms forming the aromatic hydrocarbon ring is 6 to 25. Also, m and n are 0 or 1, respectively. Also, R 105 and R 106 Each of these independently represents hydrogen or a group with a total of 1 to 100 carbon atoms, R 105 and R 106 At least one of the components has a substituent that includes a ring of any one of the following: a pyrrole ring structure, a furan ring structure, or a thiophene ring structure, via a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenylene group.

[0048] Furthermore, at least one of the heteroaromatic compounds in the above configuration may be a mixed material having a fused ring structure represented by any one of the general formulas (G1-1) to (G6-1). Note that all of the above heteroaromatic compounds may have a fused ring structure represented by any one of the general formulas (G1-1) to (G6-1), in which case not only the molecular structure of each heteroaromatic compound but also the general formulas will differ.

[0049] [ka]

[0050] In the above formula (G1-1), Z represents nitrogen, oxygen, or sulfur, and R 11 ~R 19 and R 21 ~R 28 Each of these independently represents either hydrogen, a C1 to C4 alkyl group, or a C6 to C13 substituted or unsubstituted aryl group, Ar 1 represents an arylene group having 6 to 30 carbon atoms. However, when Z represents nitrogen, Z may have hydrogen, an alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or Z may be Ar1 It may be directly coupled to R 21 ~R 28 One of the following is Ar 1 It may also form a bond with. Furthermore, the arylene group may have substituents, and these substituents may bond to each other to form a ring. Also, in the above formula (G2-1), R 51 ~R 58 Each of these independently represents one of the following: hydrogen, a C1 to C4 alkyl group, a C6 to C14 substituted or unsubstituted aryl group, a C1 to C15 substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted C1 to C6 heterocycle. Also, in the above formula (G3-1), A 2 R represents a substituent with 3 to 30 carbon atoms, containing a substituted or unsubstituted aromatic ring or a heteroaromatic ring. 81 represents hydrogen, an alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms. In addition, in the above formula (G4-1), Q represents oxygen or sulfur, and R 200 and R 201 Each of the following substituents represents one to four substituents, and each independently represents one of hydrogen, a C1 to C6 alkyl group, or a substituted or unsubstituted C6 to C13 aromatic hydrocarbon group, R 200 and R 201 If the values ​​are 2 to 4, they may be the same or different. Also, in the above formula (G5-1), Q represents oxygen or sulfur, and Ar 4 , and Ar 5 Each independently represents a substituted or unsubstituted aromatic hydrocarbon ring, and the substituents of the aromatic hydrocarbon ring are one of the following: an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, or a cyano group, and the number of carbon atoms forming the aromatic hydrocarbon ring is 6 to 30. Also, Ar 6 represents an arylene group having 6 to 13 carbon atoms, and the arylene group may have substituents, and the substituents may be bonded to each other to form a ring. Also, q is 0 or 1. Also, R 200 and R201 Each of the following substituents represents one to four atoms, and each independently represents one of hydrogen, a C1 to C6 alkyl group, or a substituted or unsubstituted C6 to C13 aromatic hydrocarbon group. In formula (G6-1), Q represents oxygen or sulfur, and Ar 4 , and Ar 5 Each independently represents a substituted or unsubstituted aromatic hydrocarbon ring, and the substituents of the aromatic hydrocarbon ring are one of the following: an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, or a cyano group, and the number of carbon atoms forming the aromatic hydrocarbon ring is 6 to 30. Also, Ar 6 represents an arylene group having 6 to 13 carbon atoms, and the arylene group may have substituents, and the substituents may be bonded to each other to form a ring. Also, q is 0 to 4. Also, R 200 and R 201 Each of these represents one to four substituents, and each independently represents one of the following: hydrogen, a C1 to C6 alkyl group, or a substituted or unsubstituted C6 to C13 aromatic hydrocarbon group.

[0051] Furthermore, a mixed material according to one aspect of the present invention may have multiple different heteroaromatic compounds from among the heteroaromatic compounds represented by structural formulas (101) to (117).

[0052] [ka]

[0053] [ka]

[0054] Furthermore, when the mixed material contains two types of heteroaromatic compounds, it is preferable to mix the heteroaromatic compound with higher electron transport properties in a ratio of 10% or more, preferably 20% or more, and more preferably 30% or more relative to the other heteroaromatic compound, as this can improve heat resistance.

[0055] Furthermore, when the heteroaromatic ring of a heteroaromatic compound contained in the above-mentioned mixed material is a condensed heteroaromatic ring, the thermophysical properties such as the glass transition temperature (Tg) and crystallization temperature (Tc) are improved compared to a mixed material containing many non-condensed compounds. However, even with condensed heteroaromatic compounds, a single film made of one compound exhibits strong intermolecular interactions, making it difficult to form and maintain a stable glassy state. As a result, although a single film made of one compound should maintain a glassy state at temperatures below Tg, crystallization that would not normally occur was observed due to exposure to air or other stimuli such as low temperatures below Tg. If a film cannot maintain a stable glassy state at temperatures below Tg, even if a process requiring processing in air is attempted to form the organic EL layer, the organic EL layer will crystallize during processing, making it impossible to provide a light-emitting device that exhibits stable characteristics. However, in one aspect of the present invention, even if the ring of one of the heteroaromatic compounds among the multiple heteroaromatic compounds is a condensed heteroaromatic ring, its crystallization can be suppressed by mixing it with the other heteroaromatic compound. In other words, by mixing multiple heteroaromatic compounds, it is possible to improve the Tg while also preventing the phenomenon of the film crystallizing below the Tg. This is demonstrated in the results shown in Examples 1 to 3.

[0056] In this embodiment, specific heteroaromatic compounds that can be used in the mixed material may be referenced if they are the same heteroaromatic compounds specifically shown as electron-transporting materials in Embodiment 2, and examples will be omitted in this embodiment.

[0057] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments.

[0058] (Embodiment 2) In this embodiment, a light-emitting device using the mixed material shown in Embodiment 1 will be described with reference to Figures 1(A) to 1(E).

[0059] ≪Basic Structure of Light-Emitting Devices≫ The basic structure of a light-emitting device will be described. Figure 1(A) shows a light-emitting device having an EL layer containing a light-emitting layer between a pair of electrodes. Specifically, it has a structure in which an EL layer 103 is sandwiched between a first electrode 101 and a second electrode 102.

[0060] Furthermore, Figure 1(B) shows a light-emitting device with a stacked structure (tandem structure) having multiple (two layers in Figure 1(B)) EL layers (103a, 103b) between a pair of electrodes, and a charge generation layer 106 between the EL layers. A light-emitting device with a tandem structure can realize a light-emitting device that can be driven at low voltage and consumes low power.

[0061] The charge generation layer 106 has the function of injecting electrons into one EL layer (103a or 103b) and holes into the other EL layer (103b or 103a) when a potential difference is created between the first electrode 101 and the second electrode 102. Therefore, in Figure 1(B), when a voltage is applied to the first electrode 101 such that its potential is higher than that of the second electrode 102, electrons are injected from the charge generation layer 106 into the EL layer 103a and holes are injected into the EL layer 103b.

[0062] Furthermore, from the viewpoint of light extraction efficiency, it is preferable that the charge generation layer 106 is transparent to visible light (specifically, the transmittance of visible light to the charge generation layer 106 is 40% or more). In addition, the charge generation layer 106 can function even if its conductivity is lower than that of the first electrode 101 and the second electrode 102.

[0063] Figure 1(C) shows the laminated structure of the EL layer 103 of a 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 EL layer 103 has a structure in which a hole injection layer 111, a hole transport layer 112, a light-emitting layer 113, an electron transport layer 114, and an electron injection layer 115 are sequentially laminated on the first electrode 101. The light-emitting layer 113 may be a configuration in which multiple light-emitting layers of different emission colors are laminated. 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 laminated, or laminated via a layer having a carrier transport material. Alternatively, a combination of a light-emitting layer containing a yellow light-emitting material and a light-emitting layer containing a blue light-emitting material may be used. However, the laminated structure of the light-emitting layer 113 is not limited to the above. For example, the light-emitting layer 113 may be a structure in which multiple light-emitting layers of the same emission 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 structure in which they are stacked via a layer having a carrier transport material. In the case of a structure in which multiple light-emitting layers of the same emission color are stacked, reliability can be increased compared to a single-layer structure. Also, even when there are multiple EL layers as in the tandem structure shown in Figure 1(B), each EL layer is stacked sequentially from the anode side as described above. Furthermore, if the first electrode 101 is the cathode and the second electrode 102 is the anode, the stacking order of the EL layer 103 is reversed. Specifically, on the first electrode 101, which is the cathode, 111 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.

[0064] The light-emitting layers 113 contained in the EL layers (103, 103a, 103b) each contain a combination of light-emitting material and multiple materials as appropriate, and can be configured to produce fluorescence or phosphorescence that exhibits a desired emission color. Alternatively, the light-emitting layers 113 may be arranged in a laminated structure with different emission colors. In this case, the light-emitting material and other materials used in each laminated light-emitting layer may be different materials. Furthermore, a configuration in which different emission colors can be obtained from multiple EL layers (103a, 103b) as shown in Figure 1(B) is also possible. In this case as well, the light-emitting material and other materials used in each light-emitting layer may be different materials.

[0065] Furthermore, in a light-emitting device according to one aspect of the present invention, for example, by using a reflective electrode as the first electrode 101 shown in Figure 1(C) and a semi-transparent / semi-reflective electrode as the second electrode 102, and by using a micro-cavity structure, the light emitted from the light-emitting layer 113 contained in the EL layer 103 can be made to resonate between the two electrodes, thereby strengthening the light emitted from the second electrode 102.

[0066] Furthermore, if the first electrode 101 of the light-emitting device is a reflective electrode consisting of a laminated structure of a reflective conductive material and a translucent 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 be mλ / 2 (where m is a natural number) or close to it, with respect to the wavelength λ of light obtained from the light-emitting layer 113.

[0067] 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 of the light-emitting layer 113 where the desired light is obtained (light-emitting region), and the optical distance from the second electrode 102 to the region of the light-emitting layer 113 where the desired light is obtained (light-emitting region), so that they are (2m'+1)λ / 4 (where m' is a natural number) or close to it. The light-emitting region referred to here is the region in the light-emitting layer 113 where holes and electrons recombine.

[0068] By performing such optical adjustments, the spectrum of specific monochromatic light obtained from the light-emitting layer 113 can be narrowed, resulting in emission with good color purity.

[0069] However, in the above case, the optical distance between the first electrode 101 and the second electrode 102 can be precisely 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 effects can be sufficiently obtained by assuming that any position on the first electrode 101 and the second electrode 102 are reflective regions. Furthermore, the optical distance between the first electrode 101 and the light-emitting layer from which the desired light is obtained can be precisely 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 the 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 the desired light is obtained, the above effects can be sufficiently obtained by assuming that any position on the first electrode 101 is a reflective region and any position on the light-emitting layer from which the desired light is obtained is a light-emitting region.

[0070] The light-emitting device shown in Figure 1(D) is a light-emitting device having a tandem structure and a microcavity structure, which allows for the extraction of light of different wavelengths (monochromatic light) from each EL layer (103a, 103b). Therefore, color separation (e.g., RGB) to obtain different emission colors is unnecessary. Consequently, high resolution can be easily achieved. It can also be combined with a colored layer (color filter). Furthermore, it is possible to strengthen the emission intensity in the front direction at a specific wavelength, thereby reducing power consumption.

[0071] The light-emitting device shown in Figure 1(E) is an example of a tandem-structured light-emitting device shown in Figure 1(B). As shown in the figure, it has a structure in which three EL layers (103a, 103b, 103c) are stacked with charge generation layers (106a, 106b) in between. Each of the three EL layers (103a, 103b, 103c) has a light-emitting layer (113a, 113b, 113c), and the light-emitting colors of each light-emitting layer can be freely combined. For example, light-emitting layer 113a can be blue, light-emitting layer 113b can be red, green, or yellow, and light-emitting layer 113c can be blue. Alternatively, light-emitting layer 113a can be red, light-emitting layer 113b can be blue, green, or yellow, and light-emitting layer 113c can be red.

[0072] In the light-emitting device according to one aspect of the present invention described above, 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-transparent / semi-reflective electrode). If the light-transmitting electrode is a transparent electrode, the transmittance of visible light of the transparent electrode shall be 40% or more. If it is a semi-transparent / semi-reflective electrode, the reflectance of visible light of the semi-transparent / semi-reflective electrode shall be 20% or more and 80% or less, preferably 40% or more and 70% or less. Furthermore, the resistivity of these electrodes shall be 1 × 10⁻⁶. -2 It is preferable to keep it below Ωcm.

[0073] Furthermore, in the light-emitting device according to one aspect of the present invention described above, if one of the first electrode 101 and the second electrode 102 is a reflective electrode (reflective electrode), the visible light reflectance of the reflective electrode is 40% or more and 100% or less, preferably 70% or more and 100% or less. In addition, the resistivity of this electrode is 1 × 10⁻⁶. -2 It is preferable to keep it below Ωcm.

[0074] ≪Specific structure of a light-emitting device≫ Next, a specific structure of a light-emitting device according to one aspect of the present invention will be described. Here, we will use Figure 1(D), which has a tandem structure, for explanation. The same applies to the EL layer configuration for the single-structure light-emitting devices shown in Figures 1(A) and 1(C). Furthermore, if the light-emitting device shown in Figure 1(D) has a microcavity structure, the first electrode 101 is formed as a reflective electrode, and the second electrode 102 is formed as a semi-transparent / semi-reflective electrode. Thus, one or more desired electrode materials can be used and formed in a single layer or in a stacked manner. The second electrode 102 is formed after the EL layer 103b is formed, by selecting a material in the same manner as described above.

[0075] <First electrode and second electrode> As materials for forming the first electrode 101 and the second electrode 102, any combination of the following materials can be used as long as the functions of both electrodes described above are met. For example, metals, alloys, electrically conductive compounds, and mixtures thereof can be used as appropriate. Specifically, these include In-Sn oxide (also called ITO), In-Si-Sn oxide (also called ITSO), In-Zn oxide, and In-W-Zn oxide. In addition, 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), and alloys containing these in appropriate combinations can also be used. In addition, elements belonging to Group 1 or Group 2 of the periodic table not exemplified above (for example, lithium (Li), cesium (Cs), calcium (Ca), strontium (Sr)), rare earth metals such as europium (Eu) and ytterbium (Yb), and alloys containing these in appropriate combinations, as well as graphene and other materials can be used.

[0076] In the light-emitting device shown in Figure 1(D), when the first electrode 101 is the anode, the hole injection layer 111a and the hole transport layer 112a of the EL layer 103a are sequentially laminated on the first electrode 101 by vacuum deposition. After the EL layer 103a and the charge generation layer 106 are formed, the hole injection layer 111b and the hole transport layer 112b of the EL layer 103b are similarly sequentially laminated on the charge generation layer 106.

[0077] <Hole injection layer> The hole injection layers (111, 111a, 111b) are layers that inject holes from the first electrode 101, which is the anode, and the charge generation layers (106, 106a, 106b) into the EL layers (103, 103a, 103b), and are layers containing organic acceptor material or a material with high hole injection potential.

[0078] Organic acceptor materials are materials that can generate holes in an organic compound by separating its charge from other organic compounds whose LUMO level and HOMO level are close. Therefore, compounds having electron-withdrawing groups (halogen groups or cyano groups), such as quinodimethane derivatives, chloranil derivatives, or hexaazatriphenylene derivatives, can be used as organic acceptor materials. For example, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviated as 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-hexazatriphenylene (abbreviated as HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviated as F6-TCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyrene-2-ylidene)malononitrile, etc. can be used. Furthermore, among organic acceptor materials, compounds in which an electron-withdrawing group is bonded to a condensed aromatic ring having multiple heteroatoms, such as HAT-CN, are particularly suitable because they have high acceptor properties and the film quality is stable with respect to heat. In addition, radialene derivatives having an electron-withdrawing group (especially a halogen group such as a fluoro group or a cyano group) [3] are also preferred because they have very high electron-accepting properties. Specifically, α,α',α''-1,2,3-cyclopropanetriylidenates[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidenates[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], and α,α',α''-1,2,3-cyclopropanetriylidenates[2,3,4,5,6-pentafluorobenzeneacetonitrile] can be used.

[0079] Furthermore, as materials with high hole injection potential, oxides of metals belonging to groups 4 through 8 of the periodic table (such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, manganese oxide, and other transition metal oxides) can be used. Specifically, examples include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among these, molybdenum oxide is preferred because it is stable in the atmosphere, has low hygroscopicity, and is easy to handle. In addition, phthalocyanine compounds such as phthalocyanine (abbreviated as H2Pc) or copper phthalocyanine (abbreviated as CuPc) can be used.

[0080] In addition to the above materials, the low molecular weight compounds 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)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviation: DNTPD), 1,3,5- Aromatic amine compounds such as tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), 3-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), and 3-[N-(1-naphthyl)-N-(9-phenylcarbazole-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1) can be used.

[0081] Furthermore, polymer compounds (oligomers, dendrimers, polymers, etc.) such as poly(N-vinylcarbazole) (abbreviated as PVK), poly(4-vinyltriphenylamine) (abbreviated as PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviated as PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviated as Poly-TPD) can be used. Alternatively, polymer compounds to which acids such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (abbreviated as PEDOT / PSS) and polyaniline / poly(styrenesulfonic acid) (abbreviated as PAni / PSS) can be added can also be used.

[0082] Furthermore, as a material with high hole injection capabilities, a mixed material containing a hole transport material and the aforementioned organic acceptor material (electron-accepting material) can also be used. 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 these holes are injected into the light-emitting layer 113 via the hole transport layer 112. The hole injection layer 111 may be formed as a single layer of a mixed material containing a hole transport material and an organic acceptor material (electron-accepting material), or it may be formed by laminating the hole transport material and the organic acceptor material (electron-accepting material) in separate layers.

[0083] Furthermore, for hole-transporting materials, the hole mobility at which the square root of the electric field strength [V / cm] is 600 is 1 × 10⁻⁶. -6 cm 2 A material having a hole mobility of / Vs or higher is preferred. However, any material that has higher hole transport than electron transport can be used.

[0084] As hole-transporting materials, materials with high hole-transporting properties such as compounds having a π-electron-rich heteroaromatic ring (e.g., carbazole derivatives, furan derivatives, or thiophene derivatives) or aromatic amines (organic compounds having an aromatic amine skeleton) are preferred.

[0085] Examples of the above-mentioned carbazole derivatives (organic compounds having a carbazole skeleton) include bicarbazole derivatives (for example, 3,3'-bicarbazole derivatives) and aromatic amines having a carbazolyl group.

[0086] Furthermore, specific examples of the above-mentioned bicarbazole derivatives (for example, 3,3'-bicarbazole derivatives) include 3,3'-bis(9-phenyl-9H-carbazole) (abbreviated as PCCP), 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviated as BisBPCz), 9,9'-bis(1,1'-biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviated as BismBPCz), 9-(1,1'-biphenyl-3-yl)-9'-(1,1'-biphenyl-4-yl)-9H,9'H-3,3'-bicarbazole (abbreviated as mBPCCBP), and 9-(2-naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviated as βNCCP).

[0087] Furthermore, examples of aromatic amines having the above-mentioned carbazolyl group include 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as PCBA1BP), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole-3-amine (abbreviated as PCBiF), and N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3- [9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl) Diphenylamine (abbreviation: PCBNBB), 4-phenyldiphenyl-(9-phenyl-9H-carbazole-3-yl)amine (abbreviation: PCA1BP), N,N'-bis(9-phenylcarbazole-3-yl)-N,N'-diphenylbenzene-1,3-diamine (abbreviation: PCA2B), N,N',N''-triphenyl-N,N',N''-tris(9-phenylcarbazole-3-yl)benzene-1,3,5-triamine (abbreviation: PCA3B), 9 ,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]spiro-9,9'-bifluoren-2-amine (abbreviation: PCBASF), 3-[N-(9-phenylcarbazole-3-yl)-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 Examples include -naphthyl)amino]-9-phenylcarbazole (abbreviation: PCzTPN2), 2-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: PCASF), N-[4-(9H-carbazole-9-yl)phenyl]-N-(4-phenyl)phenylaniline (abbreviation: YGA1BP), N,N'-bis[4-(carbazole-9-yl)phenyl]-N,N'-diphenyl-9,9-dimethylfluorene-2,7-diamine (abbreviation: YGA2F), and 4,4',4''-tris(carbazole-9-yl)triphenylamine (abbreviation: TCTA).

[0088] In addition to the above, other examples of carbazole derivatives include 3-[4-(9-phenanthryl)-phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPPn), 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPN), 1,3-bis(N-carbazolyl)benzene (abbreviated as mCP), 4,4'-di(N-carbazolyl)biphenyl (abbreviated as CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviated as CzTP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviated as TCPB), and 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviated as CzPA).

[0089] Furthermore, specific examples of the above-mentioned furan derivatives (organic compounds having a furan skeleton) 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).

[0090] Furthermore, specific examples of the above-mentioned thiophene derivatives (organic compounds having a thiophene skeleton) include 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviated as DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviated as DBTFLP-III), and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as DBTFLP-IV).

[0091] Furthermore, the above aromatic amines specifically include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as NPB or α-NPD), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviated as TPD), 4,4'-bis[N-(spiro-9,9'-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviated as BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviated as BPAFLP), and 4-phenyl-3 '-(9-phenylfluoren-9-yl)triphenylamine (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), 2-[N-(4-diphenylaminophenyl)-N-phenylamino]spiro-9 ,9'-bifluorene (abbreviation: DPASF), 2,7-bis[N-(4-diphenylaminophenyl)-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: DPA2SF), 4,4',4''-tris[N-(1-naphthyl)-N-phenylamino]triphenylamine (abbreviation: 1'-TNATA), 4,4',4''-tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4',4''-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: m-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''-diphenyltriphenyl Min (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)na Phthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-Diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4' '-phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazole-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazole-9-yl)phenyl]tris(1, 1'-biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazole-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobio[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N-bis([1,1'-bi Phenyl]-4-yl)-9,9'-spirobio[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis([1,1'-biphenyl]-4-yl)-9,9'-spirobio[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(1,1'-biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirobio[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), N,N-bis(9,9-dimethyl-9H-fluoren-2- Examples include N,N-bis(9,9-dimethyl-9H-fluoren-4-amine), N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobio-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobio-9H-fluoren-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobio-9H-fluoren-1-amine, etc.

[0092] In addition, polymer compounds (oligomers, dendrimers, polymers, etc.) such as poly(N-vinylcarbazole) (abbreviated as PVK), poly(4-vinyltriphenylamine) (abbreviated as PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviated as PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviated as Poly-TPD) can be used as hole transport materials. Alternatively, polymer compounds to which acids such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (abbreviated as PEDOT / PSS) and polyaniline / poly(styrenesulfonic acid) (abbreviated as PAni / PSS) can be added can also be used.

[0093] However, the hole transport material is not limited to the above, and various known materials may be used as a hole transport material by combining one or more of them.

[0094] The hole injection layers (111, 111a, 111b) can be formed using various known film deposition methods, for example, by vacuum deposition.

[0095] <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 containing a hole-transporting material. Therefore, the hole transport layers (112, 112a, 112b) can use the same hole-transporting material that can be used in the hole injection layers (111, 111a, 111b).

[0096] In one embodiment of the present invention, the same organic compound used in the hole transport layer (112, 112a, 112b) can be used in the light-emitting layer (113, 113a, 113b). Using the same organic compound in both the hole transport layer (112, 112a, 112b) and the light-emitting layer (113, 113a, 113b) is preferable because it allows for more efficient transport of holes from the hole transport layer (112, 112a, 112b) to the light-emitting layer (113, 113a, 113b).

[0097] <Luminous layer> The light-emitting layers (113, 113a, 113b) are layers containing a light-emitting material. The light-emitting material that can be used in the light-emitting layers (113, 113a, 113b) can be any material that exhibits a light-emitting color such as blue, purple, blue-violet, green, yellow-green, yellow, orange, or red. Furthermore, if there are multiple light-emitting layers, a configuration exhibiting different light-emitting colors can be achieved by using different light-emitting materials in each layer (for example, white light emission obtained by combining complementary light-emitting colors). Additionally, a laminated structure in which each light-emitting layer contains a different light-emitting material is also possible.

[0098] Furthermore, the light-emitting layers (113, 113a, 113b) may contain one or more types of organic compounds (host materials, etc.) in addition to the light-emitting substance (guest material).

[0099] Furthermore, when multiple host materials are used in the light-emitting layers (113, 113a, 113b), it is preferable to use a material with a larger energy gap than the energy gaps of the existing guest material and the first host material as the newly added second host material. It is also preferable that the lowest singlet excitation energy level (S1 level) of the second host material is higher than the S1 level of the first host material, and that the lowest triplet excitation energy level (T1 level) of the second host material is higher than the T1 level of the guest material. Furthermore, it is preferable that the lowest triplet excitation energy level (T1 level) of the second host material is higher than the T1 level of the first host material. With this configuration, an excitation complex can be formed using two types of host materials. In order to efficiently form the excitation complex, it is particularly preferable to combine a compound that readily accepts holes (hole transport material) with a compound that readily accepts electrons (electron transport material). This configuration also enables the simultaneous achievement of high efficiency, low voltage, and long lifespan.

[0100] The organic compounds used as the host material (including the first and second host materials) can be hole-transporting materials that can be used in the aforementioned hole-transporting layers (112, 112a, 112b), or electron-transporting materials that can be used in the electron-transporting layers (114, 114a, 114b) described later, as long as they satisfy the conditions for being a host material used in the light-emitting layer. An excited complex composed of multiple types of organic compounds (the first and second host materials) may also be used. An excited complex (also called an exciplex) that forms an excited state with multiple types of organic compounds has an extremely small difference between the S1 and T1 levels and functions as a TADF material that can convert triplet excitation energy into singlet excitation energy. Preferably, the combination of multiple types of organic compounds that form the excited complex includes, for example, a compound having a π-electron-deficient heteroaromatic ring and a compound having a π-electron-rich heteroaromatic ring. Furthermore, as a combination for forming the excitation complex, one of the components may be a phosphorescent material such as an iridium, rhodium, or platinum-based organometallic complex, or a metal complex.

[0101] There are no particular limitations on the luminescent material that can be used in the luminescent layers (113, 113a, 113b). A luminescent material that converts singlet excitation energy into visible light emission, or a luminescent material that converts triplet excitation energy into visible light emission, can be used.

[0102] <<Luminescent material that converts singlet excitation energy into light emission>> Examples of luminescent materials that can be used in the light-emitting layers (113, 113a, 113b) to convert singlet excitation energy into light include the following fluorescent materials (fluorescent materials). For example, 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 are examples. Pyrene derivatives are particularly preferred because they have a high luminescence 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, Examples include 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), and N,N'-(pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03).

[0103] Also, 5,6-bis[4-(10-phenyl-9-antryl)phenyl]-2,2'-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl-9-antryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2BPy), N,N'-bis[4-(9H-carbazole-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazole (9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: PCAPA), 4-(10-phenyl-9-anthryl)-4'- (9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBAPA), 4-[4-(10-phenyl-9-antryl)phenyl]-4'-(9-phenyl-9H-carbazole-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) Nilen)bis[N,N',N'-triphenyl-1,4-phenylenediamine] (abbreviated as DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthryl)phenyl]-9H-carbazole-3-amine (abbreviated as 2PCAPPA), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviated as 2DPAPPA), etc. can be used.

[0104] Also, N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis(1,1'-biphenyl -2-yl)-N-[4-(9H-carbazole-9-yl)phenyl]-N-phenylanthracene-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracene-9-amine (abbreviation: DPhAPhA), coumarin 545T, N,N'-diphenylquinacridone (abbreviation: DPQd), rubren, 5,12-bis(1,1'-biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyran-4-yl DCM1)propanedinitrile, 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinoridine-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (DCM2), N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5,11-diamine (p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluorantene-3,10-diamine (p -mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinoridine-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinoridine-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2,6-Bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDCM), 2-{2,6-Bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinoridine-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJTM), 1,6BnfAP Examples include rn-03, 3,10-bis[N-(9-phenyl-9H-carbazole-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10PCA2Nbf(IV)-02), and 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02). In particular, pyrenediamine compounds such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03 can be used.

[0105] <<Luminescent material that converts triplet excitation energy into light emission>> Next, examples of light-emitting materials that can be used in the light-emitting layer 113 to convert triplet excitation energy into light include phosphorescent materials (phosphorescent materials) or thermally activated delayed fluorescence (TADF) materials that exhibit thermally activated delayed fluorescence.

[0106] A phosphorescent material is a compound that exhibits phosphorescence and does not fluoresce at any temperature range above low temperatures (e.g., 77K) and below room temperature (i.e., between 77K and 313K). The phosphorescent material preferably contains a metal element with strong spin-orbit interaction, and examples include organometallic complexes, metal complexes (platinum complexes), and rare earth metal complexes. Specifically, transition metal elements are preferred, and particularly platinum group elements (ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), or platinum (Pt)) are preferred. The presence of iridium is especially preferable because it increases the transition probability involved in the direct transition between the singlet ground state and the triplet excited state.

[0107] ≪Phosphorescent materials (450nm to 570nm: blue or green)≫ Examples of phosphorescent materials that exhibit blue or green light and have a peak wavelength of emission spectrum between 450 nm and 570 nm include the following:

[0108] 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 Organometallic complexes having a 4H-triazole skeleton, such as Tris[3-(5-biphenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(iPrptz-3b)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 Organometallic complexes having a 1H-triazole skeleton such as tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Mptz1-mp)3]), tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Prptz1-Me)3]), fac-tris[1-(2,6-diisopropylf Organometallic complexes with an imidazole skeleton, such as [phenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpmi)3]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridine]iridium(III) (abbreviation: [Ir(dmpimpt-Me)3]), and bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ Iridium(III) tetrakis(1-pyrazolyl) borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridinate-N,C 2’ Iridium(III) picolinate (abbreviation: Firpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinate-N,C 2’ Iridium(III) picolinate (abbreviation: [Ir(CF3ppy)2(pic)]), bis[2-(4',6'-difluorophenyl)pyridinate-N,C 2’Examples include organometallic complexes that use phenylpyridine derivatives having electron-withdrawing groups as ligands, such as iridium(III) acetylacetonate (abbreviated as Fir(acac)).

[0109] ≪Phosphorescent materials (495nm to 590nm: green or yellow)≫ Examples of phosphorescent materials that exhibit a green or yellow color and have a peak wavelength of emission spectrum between 495 nm and 590 nm include the following:

[0110] 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- (Ir(tBuppm)2(acac)) (abbreviation: [Ir(tBuppm)2(acac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm)2(acac)]), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(mpmppm) Organometallic iridium(III) with a pyrimidine skeleton, 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 having a pyrazine skeleton, such as (acetylacetonato)bis(3,5-dimethyl-2-phenylpyradinato)iridium(III) (abbreviation: [Ir(mppr-Me)2(acac)]), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyradinato)iridium(III) (abbreviation: [Ir(mppr-iPr)2(acac)]), and tris(2-phenylpyridinato-N,C) 2’ Iridium(III) (abbreviation: [Ir(ppy)3]), bis(2-phenylpyridinate-N,C) 2’Iridium(III) acetylacetonate (abbreviation: [Ir(ppy)2(acac)]), bis(benzo[h]quinolinate)iridium(III) acetylacetonate (abbreviation: [Ir(bzq)2(acac)]), tris(benzo[h]quinolinate)iridium(III) (abbreviation: [Ir(bzq)3]), tris(2-phenylquinolinate-N,C) 2’ Iridium(III) (abbreviation: [Ir(pq)3]), bis(2-phenylquinolinato-N,C) 2’ 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)benzofl[2,3-b]pyridinyl-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]benzofl [2,3-b]pyridinyl-7-yl-κC]bis[5-(methyl-d3)-2-[5-(methyl-d3)-2-pyridinyl-κN]phenyl-κC]iridium(III) (abbreviation: Ir(5mtpy-d6)2(mbfpypy-iPr-d4)), [2-d3-methyl-(2-pyridinyl-κN)benzofloflo[2,3-b]pyridinyl-κC]bis[2-(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)) are organometallic iridium complexes having a pyridine skeleton, such as bis(2,4-diphenyl-1,3-oxazolato-N,C 2’Iridium(III) acetylacetonate (abbreviation: [Ir(dpo)2(acac)]), bis{2-[4'-(perfluorophenyl)phenyl]pyridinate-N,C 2’ Iridium(III) acetylacetonate (abbreviation: [Ir(p-PF-ph)2(acac)]), bis(2-phenylbenzothiazolat-N,C) 2’ Examples include organometallic complexes such as iridium(III) acetylacetonate (abbreviated as [Ir(bt)2(acac)]), as well as rare earth metal complexes such as tris(acetylacetonate)(monophenanthroline)terbium(III) (abbreviated as [Tb(acac)3(Phen)]).

[0111] ≪Phosphorescent materials (570nm to 750nm: yellow or red)≫ Examples of phosphorescent materials that exhibit a yellow or red color and have a peak wavelength of emission spectrum between 570 nm and 750 nm include the following:

[0112] For example, (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)]), (dipivaloylmethanato)bis[4,6-di(naphthalene-1-yl)pyrimidinato]iridium(III) (abbreviation: [Ir(d1npm)2(dpm)]), and other pyramidal compounds. Organometallic complexes having a limidine skeleton: (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)]), bis{4,6-dimethyl-2-[3-(3,5-dimethylphenyl)-5-phenyl-2-pyrazinyl-κN]phenyl-κC}(2,6-dimethyl-3,5-heptanedionato-κ 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-pyradinyl-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-κ2O,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’ Organometallic complexes having a pyrazine skeleton, such as iridium(III) (abbreviation: [Ir(dpq)2(acac)]), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq)2(acac)]), and tris(1-phenylisoquinolinato-N,C) 2’ Iridium(III) (abbreviation: [Ir(piq)3]), bis(1-phenylisoquinolinato-N,C) 2’ Iridium(III) acetylacetonate (abbreviation: [Ir(piq)2(acac)]), bis[4,6-dimethyl-2-(2-quinolinyl-κN)phenyl-κC](2,4-pentanedionato-κ 2Examples include organometallic complexes having a pyridine skeleton, 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-porphyrin platinum(II) (abbreviation: [PtOEP]), or 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-tenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: [Eu(TTA)3(Phen)]).

[0113] ≪TADF material≫ Furthermore, the following materials can be used as TADF materials. A TADF material is a material in which the difference between the S1 level and the T1 level is small (preferably 0.2 eV or less), the triplet excited state can be upconverted to the singlet excited state with a small amount of thermal energy (reverse intersystem crossing), and the emission (fluorescence) from the singlet excited state is efficiently exhibited. Furthermore, conditions for efficiently obtaining thermally activated delayed fluorescence include an energy difference between the triplet excited energy level and the singlet excited energy level being 0 eV or more and 0.2 eV or less, preferably 0 eV or more and 0.1 eV or less. In addition, delayed fluorescence in TADF materials refers to emission that has a spectrum similar to normal fluorescence but with a remarkably long lifetime. Its lifetime is 1 × 10⁻⁶ -6 For more than a second, preferably 1 × 10⁻⁶ seconds. -3 It is more than a second.

[0114] Examples of TADF materials include fullerenes or their derivatives, acridine derivatives such as proflavin, and eosin. Also, metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd) are also examples. Examples of metal-containing porphyrins include protoporphyrin-tin fluoride complexes (abbreviated as SnF2(Proto IX)), mesoporphyrin-tin fluoride complexes (abbreviated as SnF2(Meso IX)), hematoporphyrin-tin fluoride complexes (abbreviated as SnF2(Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complexes (abbreviated as SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complexes (abbreviated as SnF2(OEP)), etioporphyrin-tin fluoride complexes (abbreviated as SnF2(Etio I)), and octaethylporphyrin-platinum chloride complexes (abbreviated as PtCl2OEP).

[0115] [ka]

[0116] Other examples include 2-(biphenyl-4-yl)-4,6-bis(12-phenylindoro[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviated as PIC-TRZ), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviated as PCCzPTzn), and 2-[4-(10H-phenoxy [Sadin-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4-(5-phenyl-5,10-dihydrophenazine-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridine-10-yl)-9H-xanthene-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'-anthracene]-10'-one (abbreviation: ACRSA), 4-(9'-phenyl-3,3'-bi-9H-carbazole-9-yl)benzoflo[3,2-d]pyrimidine (abbreviation: 4PCCzBfpm), 4-[4-(9'-phenyl-3,3'- You may also use heteroaromatic compounds that have π-electron-rich heteroaromatic compounds and π-electron-deficient heteroaromatic compounds such as bi-9H-carbazole-9-yl)phenyl]benzofl[3,2-d]pyrimidine (abbreviation: 4PCCzPBfpm) and 9-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02).

[0117] Furthermore, a material in which a π-electron-rich heteroaromatic compound and a π-electron-deficient heteroaromatic compound are directly bonded is particularly preferable because both the donor properties of the π-electron-rich heteroaromatic compound and the acceptor properties of the π-electron-deficient heteroaromatic compound become stronger, and the energy difference between the singlet excited state and the triplet excited state becomes smaller. In addition, a TADF material (TADF100) in which the singlet excited state and the triplet excited state are in thermal equilibrium may be used as the TADF material. Since such a TADF material has a shorter luminescence lifetime (excitation lifetime), it is possible to suppress the decrease in efficiency in the high-brightness region of the light-emitting element.

[0118] [ka]

[0119] In addition to the above, other materials that have the function of converting triplet excitation energy into light emission include nanostructures of transition metal compounds having a perovskite structure. Nanostructures of metal halogen perovskites are particularly preferred. Nanoparticles and nanorods are preferred as such nanostructures.

[0120] In the light-emitting layers (113, 113a, 113b), the organic compounds (host materials, etc.) used in combination with the light-emitting material (guest material) described above may be one or more materials having an energy gap larger than the energy gap of the light-emitting material (guest material).

[0121] ≪Host materials for fluorescence emission≫ When the light-emitting material used in the light-emitting layers (113, 113a, 113b) is a fluorescent light-emitting material, it is preferable to use an organic compound (host material) that has a large singlet excited state energy level and a small triplet excited state energy level, or an organic compound with a high fluorescence quantum yield. Therefore, any organic compound that satisfies these conditions can be used, such as the hole transport material (described above) or electron transport material (described below) shown in this embodiment.

[0122] Although some of these overlap with the specific examples mentioned above, from the perspective of preferred combinations with luminescent substances (fluorescent substances), examples of organic compounds (host materials) include condensed polycyclic aromatic compounds such as anthracene derivatives, tetracene derivatives, phenanthrene derivatives, pyrene derivatives, chrysene derivatives, and dibenzo[g,p]chrysene derivatives.

[0123] Specific examples of organic compounds (host materials) that are preferable to use in combination with fluorescent luminescent substances include 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviated as PCzPA), 3,6-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviated as DPCzPA), 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPN), 9,10-diphenylanthracene (abbreviated as DPAnth), and N,N-diphenyl Nyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: CzA1PA), 4-(10-phenyl-9-anthryl)triphenylamine (abbreviation: DPhPA), YGAPA, PCAPA, N,9-diphenyl-N-{4-[4-(10-phenyl-9-anthryl)phenyl]phenyl}-9H-carbazole-3-amine (abbreviation: PCAPBA), N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 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]- Nzo[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,βADN), 2-(10-phenylanthracene-9-yl)dibenzofuran, 2-(10-phenyl-9-anthracenyl)-benzo[b]naphtho[2,3-d]furan (abbreviation: Bnf(II)PhA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth), 9-(2-naphthyl)-10-[3-(2-naphthyl)phenyl]anthracene (abbreviation: βN-mβNPAnth), 1-[4-(10-[1,1'-biphenyl]-4-yl-9- Examples include anthracenyl)phenyl]-2-ethyl-1H-benzimidazole (abbreviation: EtBImPBPhA), 9,9'-biantryl (abbreviation: BANT), 9,9'-(stilbene-3,3'-diyl)diphenanthrene (abbreviation: DPNS), 9,9'-(stilbene-4,4'-diyl)diphenanthrene (abbreviation: DPNS2), 1,3,5-tri(1-pyrenyl)benzene (abbreviation: TPB3), 5,12-diphenyltetracene, and 5,12-bis(biphenyl-2-yl)tetracene.

[0124] ≪Host materials for phosphorescence≫ Furthermore, when the luminescent material used in the luminescent layers (113, 113a, 113b) is a phosphorescent material, it is sufficient to select an organic compound (host material) to combine with it that has a triplet excitation energy greater than the triplet excitation energy of the luminescent material (the energy difference between the ground state and the triplet excited state). When using multiple organic compounds (for example, a first host material and a second host material (also called an assist material)) in combination with the luminescent material to form an excited complex, it is preferable to use these multiple organic compounds mixed with the phosphorescent material.

[0125] This configuration allows for efficient emission using ExTET (Exciplex-Triplet Energy Transfer), which is energy transfer from the excited complex to the luminescent material. The combination of organic compounds should ideally be one that readily forms an excited complex, and a combination of a compound that readily accepts holes (hole transport material) and a compound that readily accepts electrons (electron transport material) is particularly preferable.

[0126] In addition, although some of these examples overlap with those mentioned above, from the perspective of preferred combinations with luminescent substances (phosphorescent substances), suitable organic compounds (host materials, assist materials) include aromatic amines (organic compounds having an aromatic amine skeleton), carbazole derivatives (organic compounds having a carbazole skeleton), dibenzothiophene derivatives (organic compounds having a dibenzothiophene skeleton), dibenzofuran derivatives (organic compounds having a dibenzofuran skeleton), oxadiazole derivatives (organic compounds having an oxadiazole skeleton), triazole derivatives (organic compounds having a triazole skeleton), and benzimidazole derivatives (benzimidazole Examples include organic compounds having a zole skeleton, quinoxaline derivatives (organic compounds having a quinoxaline skeleton), dibenzoquinoxaline derivatives (organic compounds having a dibenzoquinoxaline skeleton), pyrimidine derivatives (organic compounds having a pyrimidine skeleton), triazine derivatives (organic compounds having a triazine skeleton), pyridine derivatives (organic compounds having a pyridine skeleton), bipyridine derivatives (organic compounds having a bipyridine skeleton), phenanthroline derivatives (organic compounds having a phenanthroline skeleton), phlodiazine derivatives (organic compounds having a phlodiazine skeleton), zinc or aluminum-based metal complexes, etc.

[0127] Furthermore, among the above-mentioned organic compounds, specific examples of aromatic amines and carbazole derivatives, which are organic compounds with high hole transport properties, are the same as the specific examples of hole transport materials described above, and all of these are preferred as host materials.

[0128] Furthermore, among the above organic compounds, specific examples of dibenzothiophene derivatives and dibenzofuran derivatives, which are organic compounds with high hole transport properties, 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, and 2,8-diphenyl Examples include nyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviated as DBTFLP-III), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as DBTFLP-IV), and 4-[3-(triphenylene-2-yl)phenyl]dibenzothiophene (abbreviated as mDBTPTp-II), all of which are preferred as host materials.

[0129] Other preferred host materials include metal complexes having oxazole-based or thiazole ligands such as bis[2-(2-benzoxazolyl)phenolate]zinc(II) (abbreviated as ZnPBO) and bis[2-(2-benzothiazolyl)phenolate]zinc(II) (abbreviated as ZnBTZ).

[0130] Furthermore, among the above organic compounds, specific examples of organic compounds with high electron transport properties, such as oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, quinazoline derivatives, and phenanthroline derivatives, include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (abbreviation: OXD-7), and 9-[4 -(5-phenyl-1,3,4-oxadiazole-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), 4,4'-bis Organic compounds containing heteroaromatic rings with a polyazole skeleton, such as (5-methylbenzoxazole-2-yl)stilbene (abbreviation: BzOS), vasophenanthroline (abbreviation: Bphen), vasocuproin (abbreviation: BCP), 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2-(1,3-phenylene)bis[9-phenyl-1,10-phenanthroline] (abbreviation: mPPhen2P), 2,2'-[biphenyl]-4,4'-diylbis[1,10-phenanthroline] Organic compounds containing heteroaromatic rings with a pyridine skeleton, such as 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4-(3,6-Diphenyl-9H-carbazole-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDB Examples include q-II), 2-{4-[9,10-di(2-naphthyl)-2-anthryl]phenyl}-1-phenyl-1H-benzimidazole (abbreviated as ZADN), 2-[4'-(9-phenyl-9H-carbazole-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviated as 2mpPCBPDBq), and others, all of which are preferred as host materials.

[0131] Furthermore, among the above organic compounds, specific examples of organic compounds with high electron transport capabilities include pyridine derivatives, diazine derivatives (including pyrimidine derivatives, pyrazine derivatives, and pyridazine derivatives), triazine derivatives, and phlodiazine derivatives, such as 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), and 4,6-bis[3-(9H-carbazole-9-yl)phenyl]pyrimidine (abbreviation: (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-carbazol (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)-1,1'-biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 8-(1,1'-biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofloxacin[3,2-d ]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 9-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]flo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 9-[(3'-dibenzothiophen-4-yl)biphenyl-4-yl]naphtho[1',2':4,5]flo[2,3-b]pyrazine (abbreviation: 9pmDBtBPNfpr), 5-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-[3'-(triphenylene-2-yl)-1,1'-biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mTpBPTzn), 2-[(1,1'-biphenyl)-4-yl]-4-phenyl-6-[9,9'-spirobio(9H-fluoren)-2-yl]-1 ,3,5-triazine (abbreviation: BP-SFTzn), 2,6-bis(4-naphthalene-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 9-[4-(4,6-diphenyl-1,3,5-triazine-2-yl)-2-dibenzothiophenyl]-2-phenyl-9H-carbazole (abbreviation: PCD) Examples include organic compounds containing heteroaromatic rings with a diazine skeleton, such as BfTzn, 2-[1,1'-biphenyl]-3-yl-4-phenyl-6-(8-[1,1':4',1''-terphenyl]-4-yl-1-dibenzofuranyl)-1,3,5-triazine (abbreviated as mBP-TPDBfTzn), 6-(1,1'-biphenyl-3-yl)-4-[3,5-bis(9H-carbazole-9-yl)phenyl)-2-phenylpyrimidine (abbreviated as 6mBP-4Cz2PPm), and 4-[3,5-bis(9H-carbazole-9-yl)phenyl]-2-phenyl-6-(1,1'-biphenyl-4-yl)pyrimidine (abbreviated as 6BP-4Cz2PPm), all of which are preferred as host materials.

[0132] Furthermore, among the above organic compounds, specific examples of metal complexes that are organic compounds with high electron transport properties include zinc or aluminum-based metal complexes such as tris(8-quinolinolato)aluminum(III) (abbreviated as Alq), tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviated as Almq3), bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviated as BeBq2), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviated as BAlq), bis(8-quinolinolato)zinc(II) (abbreviated as Znq), as well as metal complexes having a quinoline skeleton or a benzoquinoline skeleton, all of which are preferred as host materials.

[0133] Other preferred host materials include polymer compounds such as poly(2,5-pyridinediyl) (abbreviated as PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviated as PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviated as PF-BPy).

[0134] Furthermore, there are bipolar organic compounds that are highly hole-transporting and highly electron-transporting, such as 9-phenyl-9'-(4-phenyl-2-quinazolinyl)-3,3'-bi-9H-carbazole (abbreviation: PCCzQz), 2-[4'-(9-phenyl-9H-carbazole-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), and 5-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1 Organic compounds having a diazine skeleton, such as -b]carbazole (abbreviation: mINc(II)PTzn), 11-(4-[1,1'-biphenyl]-4-yl-6-phenyl-1,3,5-triazine-2-yl)-11,12-dihydro-12-phenyl-indoro[2,3-a]carbazole (abbreviation: BP-Icz(II)Tzn), and 7-[4-(9-phenyl-9H-carbazole-2-yl)quinazoline-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: PC-cgDBCzQz), can also be used as host materials.

[0135] <Electron transport layer> The electron transport layers (114, 114a, 114b) are layers that transport electrons injected from the second electrode 102 or the charge generation layer (106, 106a, 106b) by the electron injection layer (115, 115a, 115b), described later, to the light-emitting layer (113, 113a, 113b). The electron transport layers (114, 114a, 114b) are layers containing an electron-transporting material, and the mixed material described in Embodiment 1 is used as the electron-transporting material. Furthermore, the electron-transporting material used in the electron transport layers (114, 114a, 114b) has an electron mobility of 1 × 10⁻¹⁰ at a square root of the electric field strength [V / cm] of 600. -6 cm 2 A material having an electron mobility of / Vs or higher is preferred. However, any material with higher electron transport capabilities than hole transport can be used. Furthermore, the electron transport layer (114, 114a, 114b) can function as a single layer, but it may also be a laminated structure of two or more layers. Since the above mixed material has heat resistance, performing the photolithography process on an electron transport layer using this material can suppress the influence of the thermal process on the device characteristics.

[0136] ≪Electron transport material≫ As electron-transporting materials that can be used in the electron transport layers (114, 114a, 114b), organic compounds with high electron transport properties can be used, for example, heteroaromatic compounds can be used. A heteroaromatic compound is a cyclic compound that contains at least two different elements in its ring. The ring structure can include 3-membered rings, 4-membered rings, 5-membered rings, 6-membered rings, etc., but 5-membered rings or 6-membered rings are particularly preferred, and heteroaromatic compounds that contain one or more of the elements carbon, nitrogen, oxygen, or sulfur are preferred. Nitrogen-containing heteroaromatic compounds (nitrogen-containing heteroaromatic compounds) are particularly preferred, and it is preferable to use materials with high electron transport properties (electron-transporting materials) such as nitrogen-containing heteroaromatic compounds or π-electron-deficient heteroaromatic compounds containing them.

[0137] Heteroaromatic compounds are organic compounds that have at least one heteroaromatic ring.

[0138] Furthermore, heteroaromatic rings have one of the following skeletons: pyridine, diazine, triazine, polyazole, oxazole, or thiazole. Heteroaromatic rings having a diazine skeleton include heteroaromatic rings having a pyrimidine, pyrazine, or pyridazine skeleton. Heteroaromatic rings having a polyazole skeleton include heteroaromatic rings having an imidazole, triazole, or oxadiazole skeleton.

[0139] Furthermore, heteroaromatic rings include fused heteroaromatic rings having a fused ring structure. Examples of fused heteroaromatic rings include quinoline rings, benzoquinoline rings, quinoxaline rings, dibenzoquinoxaline rings, quinazoline rings, benzoquinazoline rings, dibenzoquinazoline rings, phenanthroline rings, phlodiazine rings, and benzimidazole rings.

[0140] Examples of heteroaromatic compounds include, among heteroaromatic compounds containing one or more of nitrogen, oxygen, or sulfur in addition to carbon, heteroaromatic compounds having a five-membered ring structure, such as heteroaromatic compounds having an imidazole skeleton, heteroaromatic compounds having a triazole skeleton, heteroaromatic compounds having an oxazole skeleton, heteroaromatic compounds having an oxadiazole skeleton, heteroaromatic compounds having a thiazole skeleton, and heteroaromatic compounds having a benzimidazole skeleton.

[0141] Furthermore, among heteroaromatic compounds that contain one or more elements other than carbon, such as nitrogen, oxygen, or sulfur, examples of heteroaromatic compounds having a six-membered ring structure include heteroaromatic compounds having heteroaromatic rings such as pyridine skeletons, diazine skeletons (including pyrimidine skeletons, pyrazine skeletons, pyridazine skeletons, etc.), triazine skeletons, and polyazole skeletons. Note that while these are included in heteroaromatic compounds with a linked pyridine skeleton, examples include heteroaromatic compounds having a bipyridine structure and heteroaromatic compounds having a terpyridine structure.

[0142] Furthermore, examples of heteroaromatic compounds having a fused ring structure that partially includes the above-mentioned six-membered ring structure include heteroaromatic compounds having fused heteroaromatic rings such as quinoline rings, benzoquinoline rings, quinoxaline rings, dibenzoquinoxaline rings, phenanthroline rings, phlodiazine rings (including skeletons in which an aromatic ring is fused to a furan ring of a phlodiazine skeleton), and benzimidazole rings.

[0143] Specific examples of heteroaromatic compounds having the above-mentioned five-membered ring structure (polyazole skeleton (including imidazole skeleton, triazole skeleton, oxadiazole skeleton), oxazole skeleton, thiazole skeleton, benzimidazole skeleton, etc.) include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated as PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (abbreviated as OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviated as CO11), and 3-(4-biphenylyl)- Examples include 4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviated as TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenylyl)-1,2,4-triazole (abbreviated as p-EtTAZ), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviated as TPBI), 2-[3-(dibenzothiophen-4)-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviated as mDBTBIm-II), and 4,4'-bis(5-methylbenzoxazole-2-yl)stilbene (abbreviated as BzOS).

[0144] Specific examples of heteroaromatic compounds having the above-mentioned six-membered ring structure (including heteroaromatic rings having pyridine, diazine, or triazine skeletons) include heteroaromatic compounds containing heteroaromatic rings having a pyridine skeleton, such as 3,5-bis[3-(9H-carbazole-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy) and 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), and 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}-4,6-diphenyl-1,3 ,5-triazine (abbreviation: PCCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 5-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-[3'-(triphenylene-2-yl)-1,1'-biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine 2-[(1,1'-biphenyl)-4-yl]-4-phenyl-6-[9,9'-spirobio(9H-fluorene)-2-yl]-1,3,5-triazine (abbreviation: BP-SFTzn), 2,6-bis(4-naphthalene-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 9-[4-(4,6-diphenyl-1,3,5-triazine-2-yl)-2-dibenzothiophenyl]-2-phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-[1,1'- [Biphenyl]-3-yl-4-phenyl-6-(8-[1,1':4',1''-terphenyl]-4-yl-1-dibenzofuranyl)-1,3,5-triazine (abbreviation: mBP-TPDBfTzn), 2-{3-[3-(dibenzothiophen-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTzn), mFBPTzn, and other heteroaromatic compounds containing heteroaromatic rings with a triazine skeleton, 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-Bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-Bis[3-(9H-carbazole-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 4,6mCzBP2Pm, 6-(1,1'-biphenyl-3-yl)-4-[3,5-bis(9H-carbazole-9-yl)phenyl)-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2 PPm), 4-[3,5-bis(9H-carbazole-9-yl)phenyl]-2-phenyl-6-(1,1'-biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 4-[3-(dibenzothiophen-4-yl)phenyl]-8-(naphthalene-2-yl)-[1]benzoflo[3,2-d]pyrimidine (abbreviation: 8βN-4mDBtPBfpm), 8BP-4mDBtPBfpm, 9mDBtBP Nfpr, 9pmDBtBPNfpr, 3,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzoflo[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzoflo[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3'-(dibenzothiophen-4-yl)(1,1'-biphenyl-3 Examples include heteroaromatic compounds containing heteroaromatic rings with a diazine (pyrimidine) skeleton, such as 8-[(2,2'-binaphthalene)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofloflo[3,2-d]pyrimidine (abbreviated as 8(βN2)-4mDBtPBfpm). Note that the above aromatic compounds containing heteroaromatic rings include heteroaromatic compounds having condensed heteroaromatic rings.

[0145] Other compound compounds with a diazine (pyrimidine) skeleton include 2,2'-(pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6(P-Bqn)2Py), 2,2'-(pyridine-2,6-diyl)bis{4-[4-(2-naphthyl)phenyl]-6-phenylpyrimidine} (abbreviation: 2,6(NP-PPm)2Py), and 6-(1,1'-biphenyl-3-yl)-4-[3,5-bis(9H-carbazole-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm). Examples include heteroaromatic compounds containing a triazine skeleton, such as 2,4,6-tris(3'-(pyridine-3-yl)biphenyl-3-yl)-1,3,5-triazine (abbreviated as TmPPPyTz), 2,4,6-tris(2-pyridyl)-1,3,5-triazine (abbreviated as 2Py3Tz), and 2-[3-(2,6-dimethyl-3-pyridyl)-5-(9-phenanthryl)phenyl)-4,6-diphenyl-1,3,5-triazine (abbreviated as mPn-mDMePyPTzn).

[0146] Specific examples of heteroaromatic compounds having a fused ring structure that partially includes a 6-membered ring structure (heteroaromatic compounds having a fused ring structure) include: vasophenanthroline (abbreviation: Bphen), vasocuproin (abbreviation: BCP), 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2-(1,3-phenylene)bis[9-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), and 2-[3'-(dibenzothiophen-4-yl) [biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4-(3,6-diphenyl-9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPD Examples include heteroaromatic compounds having a quinoxaline ring, such as Bq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 2mpPCBPDBq, etc.

[0147] In addition to the heteroaromatic compounds shown above, the following metal complexes can be used in the electron transport layers (114, 114a, 114b). Examples include metal complexes having a quinoline or benzoquinoline skeleton such as tris(8-quinolinolato)aluminum(III) (abbreviated as Alq3), Almq3, 8-quinolinolatritium(I) (abbreviated as Liq), BeBq2, bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviated as BAlq), and bis(8-quinolinolato)zinc(II) (abbreviated as Znq), as well as metal complexes having an oxazole or thiazole skeleton such as bis[2-(2-benzoxazollyl)phenolato]zinc(II) (abbreviated as ZnPBO) and bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviated as ZnBTZ).

[0148] Furthermore, polymer compounds such as poly(2,5-pyridinediyl) (abbreviated as PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviated as PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviated as PF-BPy) can also be used as electron transport materials.

[0149] Furthermore, the electron transport layers (114, 114a, 114b) may be not only single layers, but also have a structure in which two or more layers made of the above material are stacked.

[0150] <Electron injection layer> The electron injection layers (115, 115a, 115b) are layers containing a material with high electron injection capabilities. Furthermore, the electron injection layers (115, 115a, 115b) are layers for increasing the electron injection efficiency from the second electrode 102, and it is preferable to use a material in which the difference between the work function value of the material used for the second electrode 102 and the LUMO level value of the material used for the electron injection layers (115, 115a, 115b) is small (0.5 eV or less). Therefore, the electron injection layer 115 contains lithium, cesium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), 8-(quinolinolato)lithium (abbreviated as Liq), 2-(2-pyridyl)phenolate (abbreviated as LiPP), 2-(2-pyridyl)-3-pyridinolatritium (abbreviated as LiPPy), 4-phenyl-2-(2-pyridyl)phenolate (abbreviated as LiPPP), and lithium oxide (LiO x Alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. Rare earth metals such as erbium fluoride (ErF3) or compounds thereof can also be used. The electron injection layers (115, 115a, 115b) may be formed by mixing multiple types of the above materials, or by stacking multiple types of the above materials. Electrides may also be used in the electron injection layers (115, 115a, 115b). Examples of electrides include substances obtained by adding a high concentration of electrons to a mixed oxide of calcium and aluminum. The materials that constitute the electron transport layers (114, 114a, 114b) described above can also be used.

[0151] Furthermore, a mixed material comprising an organic compound and an electron donor may be used in the electron injection layers (115, 115a, 115b). Such a mixed material exhibits 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 with excellent electron transport properties. Specifically, for example, an electron transport material (metal complex or heteroaromatic compound, etc.) used in the electron transport layers (114, 114a, 114b) described above can be used. The electron donor can be any substance that exhibits electron-donating properties to the organic compound. Specifically, alkali metals, alkaline earth metals, or rare earth metals are preferred, such as lithium, cesium, magnesium, calcium, erbium, and ytterbium. Alkali metal oxides or alkaline earth metal oxides are also preferred, such as lithium oxide, calcium oxide, and barium oxide. Lewis bases such as magnesium oxide can also be used. Furthermore, organic compounds such as tetrathiafulvalene (abbreviated as TTF) can also be used. Furthermore, multiple layers of these materials may be used.

[0152] In addition, a mixed material consisting of an organic compound and a metal may be used for the electron injection layers (115, 115a, 115b). The organic compound used here preferably has a LUMO (Lowest Unoccupied Molecular Orbital) level of -3.6 eV or higher and -2.3 eV or lower. Furthermore, a material having lone pairs of electrons is preferred.

[0153] Therefore, as the organic compound used in the above-mentioned mixed material, a mixed material obtained by mixing a heteroaromatic compound with a metal, as described above for use in an electron transport layer, may be used. Preferred heteroaromatic compounds include materials having lone pairs of electrons, such as heteroaromatic compounds having a 5-membered ring structure (imidazole skeleton, triazole skeleton, oxazole skeleton, oxadiazole skeleton, thiazole skeleton, benzimidazole skeleton, etc.), heteroaromatic compounds having a 6-membered ring structure (pyridine skeleton, diazine skeleton (including pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton, etc.), triazine skeleton, bipyridine skeleton, terpyridine skeleton, etc.), and heteroaromatic compounds having a fused ring structure that partially includes a 6-membered ring structure (quinoline skeleton, benzoquinoline skeleton, quinoxaline skeleton, dibenzoquinoxaline skeleton, phenanthroline skeleton, etc.). Specific materials have been described above, so further explanation is omitted here.

[0154] Furthermore, it is preferable to use transition metals belonging to Group 5, Group 7, Group 9, or Group 11 of the periodic table, or materials belonging to Group 13, as the metals used in the above-mentioned mixed material. Examples include Ag, Cu, Al, or In. In this case, the organic compound forms a half-occupied orbital (SOMO) with the transition metal.

[0155] For example, when amplifying the light obtained from the light-emitting layer 113b, it is preferable to form the optical distance between the second electrode 102 and the light-emitting layer 113b to be less than 1 / 4 of the wavelength λ of the light emitted by the light-emitting layer 113b. In this case, this can be adjusted by changing the film thickness of the electron transport layer 114b or the electron injection layer 115b.

[0156] Furthermore, as shown in the light-emitting device in Figure 1(D), by providing a charge generation layer 106 between two EL layers (103a, 103b), a structure in which multiple EL layers are stacked between a pair of electrodes (also called a tandem structure) can be created.

[0157] <Charge generation layer> The charge generation layer 106 has the function of injecting electrons into the EL layer 103a and holes into the EL layer 103b when a voltage is applied between the first electrode (anode) 101 and the second electrode (cathode) 102. The charge generation layer 106 may be configured with electron acceptors added to a hole transport material, or with electron donors added to an electron transport material. Alternatively, both of these configurations may be laminated. By forming the charge generation layer 106 using the materials described above, the increase in driving voltage when the EL layers are laminated can be suppressed.

[0158] In the charge generation layer 106, if an electron acceptor is added to a hole-transporting material which is an organic compound, the material shown in this embodiment can be used as the hole-transporting material. Examples of electron acceptors include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviated as F4-TCNQ), chloranil, etc. Other examples include oxides of metals belonging to groups 4 through 8 of the periodic table. Specifically, examples include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide.

[0159] Furthermore, in the charge generation layer 106, if an electron donor is added to the electron transport material, the material shown in this embodiment can be used as the electron transport material. As the electron donor, alkali metals, alkaline earth metals, rare earth metals, or metals belonging to groups 2 and 13 of the periodic table, as well as their oxides and carbonates, can be used. Specifically, lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium oxide, cesium carbonate, etc., are preferred. Organic compounds such as tetrathianaphthalene may also be used as electron donors.

[0160] Although Figure 1(D) shows a configuration in which two EL layers 103 are stacked, a stacked structure of three or more EL layers may be used by providing a charge generation layer between different EL layers.

[0161] <Circuit board> The light-emitting device shown in this embodiment can be formed on various substrates. The type of substrate is not limited to any particular type. Examples of substrates include semiconductor substrates (e.g., single crystal substrates or silicon substrates), SOI substrates, glass substrates, quartz substrates, plastic substrates, metal substrates, stainless steel substrates, substrates with stainless steel foil, tungsten substrates, substrates with tungsten foil, flexible substrates, laminated films, paper containing fibrous materials, or base films.

[0162] Examples of glass substrates include barium borosilicate glass, aluminobrosilicate glass, or soda-lime glass. Examples of flexible substrates, laminated films, and base films include plastics such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyethersulfone (PES), synthetic resins such as acrylic, polypropylene, polyester, polyvinyl fluoride, or polyvinyl chloride, polyamide, polyimide, aramid, epoxy, inorganic vapor-deposited films, or paper.

[0163] In addition to vapor-phase methods such as vapor deposition, liquid-phase methods such as spin coating or inkjet can be used to fabricate the light-emitting device shown in this embodiment. When using vapor deposition, physical vapor deposition methods (PVD) such as sputtering, ion plating, ion beam deposition, molecular beam deposition, and vacuum deposition, or chemical vapor deposition (CVD) can be used. In particular, the various functional layers included in the EL layer of the light-emitting device (hole injection layer 111, hole transport layer 112, light-emitting layer 113, electron transport layer 114, electron injection layer 115) can be formed by methods such as vapor deposition (vacuum deposition, etc.), coating (dip coating, die coating, bar coating, spin coating, spray coating, etc.), and printing (inkjet, screen printing, offset printing, flexographic printing, gravure printing, microcontact printing, etc.).

[0164] Furthermore, when applying the above-mentioned coating method, printing method, or other film formation method, polymer compounds (oligomers, dendrimers, polymers, etc.), medium-molecular-weight compounds (compounds in the intermediate region between low-molecular-weight and high-molecular-weight compounds: molecular weight 400-4000), inorganic compounds (quantum dot materials, etc.) can be used. As for 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.

[0165] The layers constituting the EL 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, 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 satisfy the function of each layer.

[0166] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments.

[0167] (Embodiment 3) This embodiment describes a specific configuration example and manufacturing method of a light-emitting device (also called a display panel) which is one aspect of the present invention.

[0168] <Example of configuration of light-emitting device 700 1> The light-emitting device 700 shown in Figure 2(A) includes light-emitting devices 550B, 550G, 550R, and a partition wall 528. The light-emitting devices 550B, 550G, 550R, and the partition wall 528 are formed on a functional layer 520 provided on a first substrate 510. The functional layer 520 includes a drive circuit GD and a drive circuit SD, both composed of multiple transistors, as well as wiring to electrically connect them. These drive circuits are, for example, electrically connected to the light-emitting devices 550B, 550G, and 550R, respectively, and can drive them. The light-emitting device 700 also includes an insulating layer 705 on the functional layer 520 and each light-emitting device, and the insulating layer 705 has the function of bonding the second substrate 770 to the functional layer 520. The drive circuits GD and SD will be described later in Embodiment 4.

[0169] Furthermore, the light-emitting devices 550B, 550G, and 550R have the device structure shown in Embodiment 2. That is, this shows the case where the EL layer 103 in the structure shown in Figure 1(A) differs for each light-emitting device.

[0170] In this specification, a structure in which different light-emitting layers are created or painted for each color of light-emitting device (e.g., blue (B), green (G), and red (R)) may be referred to as an SBS (Side By Side) structure.

[0171] As shown in Figure 2(A), the light-emitting device 550B has an electrode 551B, an electrode 552, and an EL layer 103B. The specific configuration of each layer is as shown in Embodiment 2. The EL layer 103B has a laminated structure consisting of multiple layers with different functions, including the light-emitting layer. In Figure 2(A), only the hole injection / transport layer 104B, the electron transport layer 108B, and the electron injection layer 109 are shown among the layers included in the EL layer 103B, which includes the light-emitting layer, but the present invention is not limited to these. The hole injection / transport layer 104B refers to a layer having the functions of a hole injection layer and a hole transport layer as shown in Embodiment 2, and may have a laminated structure. In this specification, the hole injection / transport layer can be interpreted in this way in any light-emitting device.

[0172] Furthermore, it is preferable to use the mixed material shown in Embodiment 1 for the electron transport layer 108B. The mixed material shown in Embodiment 1 has a plurality of heteroaromatic compounds, and each heteroaromatic compound is a mixed material having at least one heteroaromatic ring. In addition, at least one of the plurality of heteroaromatic compounds is a condensed heteroaromatic ring having a fused ring structure. Furthermore, it is a mixed material formed by combining a plurality of heteroaromatic compounds represented by general formulas (G1) to (G6) or general formulas (G1-1) to (G6-1), each having a different general formula. The electron transport layer 108B may also have a function to block holes moving from the anode side through the light-emitting layer to the cathode side. Furthermore, the electron injection layer 109 may also have a laminated structure formed using some or all different materials.

[0173] Furthermore, as shown in Figure 2(A), insulating layers 107 may be formed on the sides (or edges) of the layers included in the EL layer 103B, which includes the light-emitting layer: the hole injection / transport layer 104B, the light-emitting layer, and the electron transport layer 108B. The insulating layer 107 is formed in contact with the sides (or edges) of the EL layer 103B. This suppresses the penetration of oxygen or moisture, as well as substances containing these constituent elements, into the interior from the sides of the EL layer 103B. For example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, or silicon nitride oxide can be used for the insulating layer 107. The insulating layer 107 may also be formed by laminating the aforementioned materials. Sputtering, CVD, MBE, PLD, ALD, etc., can be used to form the insulating layer 107, but the ALD method, which has good coverage, is more preferable.

[0174] Furthermore, an electron injection layer 109 is formed covering a portion of the EL layer 103B (including the light-emitting layer, the hole injection / transport layer 104B, and the electron transport layer 108B) and the insulating layer 107. The electron injection layer 109 may also be a laminated structure of two or more layers with different electrical resistances within the layers.

[0175] Furthermore, electrode 552 is formed on the electron injection layer 109. Electrode 551B and electrode 552 have overlapping regions. Additionally, an EL layer 103B is present between electrode 551B and electrode 552.

[0176] Furthermore, the EL layer 103B shown in Figure 2(A) has the same configuration as the EL layer 103 described in Embodiment 2. In addition, the EL layer 103B can emit, for example, blue light.

[0177] As shown in Figure 2(A), the light-emitting device 550G has an electrode 551G, an electrode 552, and an EL layer 103G. The specific configuration of each layer is as shown in Embodiment 2. The EL layer 103G has a laminated structure consisting of multiple layers with different functions, including the light-emitting layer. In Figure 2(A), only the hole injection / transport layer 104G, the electron transport layer 108G, and the electron injection layer 109 are shown among the layers included in the EL layer 103G, which includes the light-emitting layer, but the present invention is not limited to these. The hole injection / transport layer 104G refers to a layer having the functions of a hole injection layer and a hole transport layer as shown in Embodiment 2, and may have a laminated structure.

[0178] Furthermore, it is preferable to use the mixed material shown in Embodiment 1 for the electron transport layer 108G. The mixed material shown in Embodiment 1 has a plurality of heteroaromatic compounds, and each heteroaromatic compound is a mixed material having at least one heteroaromatic ring. In addition, at least one of the plurality of heteroaromatic compounds is a condensed heteroaromatic ring in which the heteroaromatic ring has a fused ring structure. Furthermore, it is a mixed material formed by combining a plurality of heteroaromatic compounds represented by general formulas (G1) to (G6) or general formulas (G1-1) to (G6-1), each having a different general formula. The electron transport layer 108G may also have a function to block holes moving from the anode side through the light-emitting layer to the cathode side. In addition, the electron injection layer 109 may also have a laminated structure formed using some or all different materials.

[0179] Furthermore, as shown in Figure 2(A), insulating layers 107 may be formed on the sides (or edges) of the layers included in the EL layer 103G, which includes the light-emitting layer: the hole injection / transport layer 104G, the light-emitting layer, and the electron transport layer 108G. The insulating layer 107 is formed in contact with the sides (or edges) of the EL layer 103G. This suppresses the penetration of oxygen, moisture, and other constituent elements into the interior from the sides of the EL layer 103G. For example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, or silicon oxide nitride can be used for the insulating layer 107. The insulating layer 107 may also be formed by laminating the aforementioned materials. Sputtering, CVD, MBE, PLD, ALD, etc., can be used to form the insulating layer 107, but the ALD method, which has good coverage, is more preferable.

[0180] Furthermore, an electron injection layer 109 is formed covering a portion of the EL layer 103G (including the light-emitting layer, the hole injection / transport layer 104G, and the electron transport layer 108B) and the insulating layer 107. The electron injection layer 109 may also be a laminated structure of two or more layers with different electrical resistances within the layers.

[0181] Furthermore, electrode 552 is formed on the electron injection layer 109. Electrode 551G and electrode 552 have overlapping regions. Additionally, an EL layer 103G is present between electrode 551G and electrode 552.

[0182] Furthermore, the EL layer 103G shown in Figure 2(A) has the same configuration as the EL layer 103 described in Embodiment 2. In addition, the EL layer 103G can emit, for example, green light.

[0183] As shown in FIG. 2(A), the light-emitting device 550R has an electrode 551R, an electrode 552, and an EL layer 103R. The specific configuration of each layer is as shown in Embodiment 2. The EL layer 103R has a stacked structure composed of a plurality of layers with different functions including a light-emitting layer. In FIG. 2(A), among the layers included in the EL layer 103R including the light-emitting layer, only the hole injection / transport layer 104R, the electron transport layer 108R, and the electron injection layer 109 are illustrated, but the present invention is not limited thereto. The hole injection / transport layer 104R indicates a layer having the functions of the hole injection layer and the hole transport layer shown in Embodiment 2, and may have a stacked structure.

[0184] Further, it is preferable to use the mixed material shown in Embodiment 1 for the electron transport layer 108R. The mixed material shown in Embodiment 1 has a plurality of heteroaromatic compounds, and each heteroaromatic compound is a mixed material having at least one heteroaromatic ring. Among the plurality of heteroaromatic compounds, at least one is a condensed heteroaromatic ring in which the heteroaromatic ring has a condensed ring structure. It is also a heteroaromatic compound represented by General Formulas (G1) to (G6) or General Formulas (G1-1) to (G6-1), and is a mixed material in which a plurality of heteroaromatic compounds having different general formulas are combined. The electron transport layer 108R may have a function of blocking holes that move from the anode side through the light-emitting layer to the cathode side. Also, the electron injection layer 109 may have a stacked structure in which part or all thereof is formed using different materials.

[0185] Further, among the layers included in the EL layer 103R including the light-emitting layer as shown in FIG. 2(A), an insulating layer 107 may be formed on the side surfaces (or ends) of the hole injection / transport layer 104R, the light-emitting layer, and the electron transport layer 108R. The insulating layer 107 is formed in contact with the side surface (or end) of the EL layer 103R. Thereby, intrusion of oxygen, moisture, or other constituent elements from the side surface of the EL layer 103R into the interior can be suppressed. For the insulating layer 107, for example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, or silicon oxynitride can be used. Further, the insulating layer 107 may be formed by laminating the above-described materials. Further, for forming the insulating layer 107, a sputtering method, a CVD method, an MBE method, a PLD method, an ALD method, etc. can be used, but the ALD method with good coating properties is more preferable.

[0186] Further, an electron injection layer 109 is formed to cover a part of the EL layer 103R (including the light-emitting layer, the hole injection / transport layer 104R, and the electron transport layer 108R) and the insulating layer 107R. Note that the electron injection layer 109 may have a laminated structure of two or more layers having different electrical resistances in the layer.

[0187] Further, the electrode 552 is formed on the electron injection layer 109. Note that the electrode 551R and the electrode 552 have an overlapping region with each other. Also, the EL layer 103R is provided between the electrode 551R and the electrode 552.

[0188] Further, the EL layer 103R shown in FIG. 2(A) has the same configuration as the EL layer 103 described in Embodiment 2. Further, the EL layer 103R can emit, for example, red light.

[0189] Partition walls 528 are provided between the EL layer 103B, the EL layer 103G, and the EL layer 103R, respectively. As shown in FIG. 2(A), the EL layers (EL layer 103B, EL layer 103G, EL layer 103R) of each light-emitting device and the partition wall 528 are in contact with each other at the side surface (or end) via the insulating layer 107.

[0190] In each EL layer, the hole injection layer, particularly the hole transport region located between the anode and the light-emitting layer, often has high conductivity. Therefore, if it is formed as a common layer for adjacent light-emitting devices, it can cause crosstalk. Accordingly, as shown in this example configuration, by providing a partition wall 528 made of insulating material between each EL layer, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0191] Furthermore, in the manufacturing method described in this embodiment, the side (or edge) of the EL layer is exposed during the patterning process. As a result, the EL layer is more susceptible to deterioration due to the intrusion of oxygen or water from the side (or edge) of the EL layer. Therefore, by providing the partition wall 528, it is possible to suppress the deterioration of the EL layer during the manufacturing process.

[0192] Furthermore, by providing the partition wall 528, it is possible to flatten the recess formed between adjacent light-emitting devices. Flattening the recess helps to suppress disconnection of the electrodes 552 formed on each EL layer. As the insulating material used to form the partition wall 528, organic materials such as acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimidoamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins can be used. Alternatively, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin may be used. Photosensitive resins such as photoresists can also be used. The photosensitive resin can be either a positive-type or negative-type material.

[0193] Furthermore, the difference between the height of the upper surface of the partition wall 528 and the height of the upper surface of any of the EL layers 103B, 103G, and 103R is preferably 0.5 times or less the thickness of the partition wall 528, and more preferably 0.3 times or less. Also, for example, an insulating layer may be provided such that the upper surface of any of the EL layers 103B, 103G, and 103R is higher than the upper surface of the partition wall 528. Also, for example, the partition wall 528 may be provided such that the upper surface of the partition wall 528 is higher than the upper surface of the light-emitting layer of the EL layer 103B, 103G, and 103R.

[0194] In a high-resolution light-emitting device (display panel) with a resolution exceeding 1000 ppi, if electrical conductivity is detected between the EL layer 103B, EL layer 103G, and EL layer 103R, a crosstalk phenomenon occurs, narrowing the color gamut that the light-emitting device can display. By providing a partition wall 528 in a high-resolution display panel exceeding 1000 ppi, preferably a high-resolution display panel exceeding 2000 ppi, and more preferably an ultra-high-resolution display panel exceeding 5000 ppi, a display panel capable of displaying vivid colors can be provided.

[0195] Figure 2(B) shows a schematic top view of the light-emitting device 700 corresponding to the dashed line Ya-Yb in the cross-sectional view of Figure 2(A). That is, light-emitting devices 550B, 550G, and 550R are arranged in a matrix. Figure 2(B) shows a so-called stripe arrangement in which light-emitting devices of the same color are arranged in the Y direction. In addition, light-emitting devices of the same color are arranged in the X direction, which intersects with the Y direction. Note that the arrangement method of the light-emitting devices is not limited to this, and arrangement methods such as delta arrangement and zigzag arrangement may be applied, or pentile arrangement and diamond arrangement may be used.

[0196] Furthermore, since the separation process of each EL layer (EL layer 103B, EL layer 103G, and EL layer 103R) is performed using photolithography to form patterns, a high-definition light-emitting device (display panel) can be manufactured. In addition, the edges (sides) of the EL layers processed by the photolithography pattern formation have a shape that is substantially the same surface (or substantially located on the same plane). At this time, the width (SE) of the gap 580 between each EL layer is preferably 5 μm or less, and more preferably 1 μm or less.

[0197] In EL layers, the hole injection layer, particularly the hole transport region located between the anode and the light-emitting layer, often has high conductivity. Therefore, if it is formed as a common layer for adjacent light-emitting devices, it can cause crosstalk. Consequently, by separating the EL layer using photolithography, as shown in this example configuration, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0198] Furthermore, Figure 2(C) is a schematic cross-sectional view corresponding to the dashed line C1-C2 in Figure 2(B). Figure 2(C) shows the connection portion 130 where the connecting electrode 551C and electrode 552 are electrically connected. At the connection portion 130, electrode 552 is provided in contact with the connecting electrode 551C. In addition, a partition wall 528 is provided covering the end of the connecting electrode 551C.

[0199] <Example 1 of a manufacturing method for a light-emitting device> As shown in Figure 3(A), electrodes 551B, 551G, and 551R are formed. For example, a conductive film is formed on a functional layer 520 formed on the first substrate 510, and then processed into a predetermined shape using photolithography.

[0200] Conductive films can be formed using methods such as sputtering, chemical vapor deposition (CVD), molecular beam epitaxy (MBE), vacuum deposition, pulsed laser deposition (PLD), and atomic layer deposition (ALD). CVD methods include plasma-enhanced CVD (PECVD) and thermal CVD. One type of thermal CVD is metal-organic CVD (MOCVD).

[0201] In addition to the photolithography method described above, conductive films may also be processed using nanoimprint lithography, sandblasting, lift-off methods, etc. Island-like thin films may also be directly formed using a film deposition method that utilizes a shielding mask such as a metal mask.

[0202] There are two main methods of photolithography. One method involves forming a resist mask on a thin film to be processed, processing the thin film by etching or other means, and then removing the resist mask. The other method involves forming a photosensitive thin film, then exposing and developing it to process the thin film into a desired shape. The former method involves heat treatment steps such as heating after resist coating (PAB: Pre-Applied Bake) and heating after exposure (PEB: Post-Exposure Bake). In one aspect of the present invention, lithography is used not only for processing conductive films but also for processing thin films (films made of organic compounds, or films containing organic compounds in part) used to form an EL layer.

[0203] 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 thereof. Other options include ultraviolet light, KrF laser light, or ArF laser light. Exposure may also be performed using immersion lithography. Furthermore, extreme ultraviolet (EUV) light or X-rays may be used as the light source for exposure. An electron beam can also be used instead of light for exposure. Using extreme ultraviolet light, X-rays, or an electron beam is preferable because it allows for extremely fine processing. Note that a photomask is not required when exposure is performed by scanning a beam such as an electron beam.

[0204] For etching thin films using a resist mask, methods such as dry etching, wet etching, and sandblasting can be used.

[0205] Next, as shown in Figure 3(B), an EL layer 103B is formed on electrodes 551B, 551G, and 551R. In Figure 3(B), the EL layer 103B is formed up to the hole injection / transport layer 104B, the light-emitting layer, and the electron transport layer 108B. For example, the EL layer 103B is formed on electrodes 551B, 551G, and 551R using a vacuum deposition method, covering them. Furthermore, a sacrificial layer 110B is formed on the EL layer 103B.

[0206] The sacrificial layer 110B can be a film with high resistance to etching of the EL layer 103B, i.e., a film with a high etching selectivity ratio. Furthermore, it is preferable that the sacrificial layer 110B has a laminated structure of a first sacrificial layer and a second sacrificial layer with different etching selectivity ratios. Additionally, the sacrificial layer 110B can be a film that can be removed by a wet etching method that causes minimal damage to the EL layer 103B. Oxalic acid can be used as the etching material for wet etching.

[0207] As the sacrificial layer 110B, for example, inorganic films such as metal films, alloy films, metal oxide films, semiconductor films, and inorganic insulating films can be used. Further, the sacrificial layer 110B can be formed by various film forming methods such as sputtering, vapor deposition, CVD, and ALD.

[0208] As the sacrificial layer 110B, for example, 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 the metal materials can be used. In particular, it is preferable to use a low melting point material such as aluminum or silver.

[0209] Further, as the sacrificial layer 110B, metal oxides such as indium gallium zinc oxide (also denoted as In-Ga-Zn oxide, IGZO) can be used. Further, indium oxide, indium zinc oxide (In-Zn oxide), indium tin oxide (In-Sn oxide), indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), etc. can be used. Alternatively, indium tin oxide containing silicon, etc. can also be used.

[0210] Note that instead of the above gallium, an element M (M is one or more selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium) can also be used. In particular, it is preferable that M is one or more selected from gallium, aluminum, or yttrium.

[0211] Further, as the sacrificial layer 110B, inorganic insulating materials such as aluminum oxide, hafnium oxide, and silicon oxide can be used.

[0212] Furthermore, it is preferable to use a material that is soluble in a chemically stable solvent for at least the film located at the top of the EL layer 103B (electron transport layer 108B) as the sacrificial layer 110B. In particular, a material soluble in water or alcohol can be suitably used for the sacrificial layer 110B. When forming the sacrificial layer 110B, it is preferable to dissolve the material in a solvent such as water or alcohol, apply it using a wet deposition method, and then perform a heat treatment to evaporate the solvent. At this time, performing the heat treatment under a reduced pressure atmosphere is preferable because it allows the solvent to be removed at a low temperature and in a short time, thereby reducing thermal damage to the EL layer 103B.

[0213] Furthermore, when the sacrificial layer 110B is to be made into a laminated structure, the layer formed from the above-mentioned material can be designated as the first sacrificial layer, and a second sacrificial layer can be formed below it to create a laminated structure.

[0214] In this case, the second sacrificial layer is a film used as a hard mask when etching the first sacrificial layer. Furthermore, the first sacrificial layer is exposed during processing of the second sacrificial layer. Therefore, the first and second sacrificial layers are selected based on a combination of films that have a high etching selectivity ratio for each other. Thus, the film that can be used for the second sacrificial layer can be selected according to the etching conditions for both the first and second sacrificial layers.

[0215] For example, when dry etching using a fluorine-containing gas (also called a fluorine-based gas) is used for etching the second sacrificial layer, silicon, silicon nitride, silicon oxide, tungsten, titanium, molybdenum, tantalum, tantalum nitride, alloys containing molybdenum and niobium, or alloys containing molybdenum and tungsten can be used for the second sacrificial layer. Here, metal oxide films such as IGZO and ITO can be used for the first sacrificial layer as films that allow for a higher selectivity ratio for etching (i.e., a slower etching rate) compared to dry etching using the above-mentioned fluorine-based gas.

[0216] However, the second sacrificial layer can be selected from a variety of materials, depending on the etching conditions of the first sacrificial layer and the etching conditions of the second sacrificial layer. For example, it can be selected from among the films that can be used for the first sacrificial layer.

[0217] Furthermore, a nitride film can be used as the second sacrificial layer. Specifically, nitrides such as silicon nitride, aluminum nitride, hafnium nitride, titanium nitride, tantalum nitride, tungsten nitride, gallium nitride, and germanium nitride can be used.

[0218] Alternatively, an oxide film can be used as the second sacrificial layer. Typically, oxide films or oxynitride films such as silicon oxide, silicon oxynitride, aluminum oxide, aluminum oxynitride, hafnium oxide, and hafnium oxynitride can be used.

[0219] Next, as shown in Figure 3(C), a resist is applied to the sacrificial layer 110B, and the resist is formed into a desired shape (resist mask: REG) using photolithography. Note that this method involves heat treatment steps such as heating after resist application (PAB: Pre-Applied Bake) and heating after exposure (PEB: Post-Exposure Bake). For example, the PAB temperature is around 100°C, and the PEB temperature is around 120°C. Therefore, the light-emitting device must be able to withstand these processing temperatures. In one embodiment of the present invention, the layer exposed to photolithography is specifically a highly heat-resistant layer made of a mixed material, as described in Embodiment 1. This suppresses the effects of heat treatment, resulting in a light-emitting device with high reliability.

[0220] Next, using the obtained resist mask REG, a portion of the sacrificial layer 110B not covered by the resist mask REG is removed by etching. After removing the resist mask REG, a portion of the EL layer 103B not covered by the sacrificial layer 110B is removed by etching. The EL layer 103B on electrode 551G and the EL layer 103B on electrode 551R are removed by etching to process the material into a shape with sides (or with exposed sides) or a strip shape extending in a direction intersecting the plane of the paper. Specifically, dry etching is performed using the sacrificial layer 110B with a pattern formed on the EL layer 103B overlapping electrode 551B. If the sacrificial layer 110B has a laminated structure with the first sacrificial layer and the second sacrificial layer, a portion of the second sacrificial layer may be etched with the resist mask REG, then the resist mask REG is removed, and the second sacrificial layer is used as a mask to etch a portion of the first sacrificial layer and process the EL layer 103B into a predetermined shape. These etching processes yield the shape shown in Figure 4(A).

[0221] Next, as shown in Figure 4(B), the EL layer 103G is formed on the sacrificial layer 110B, electrode 551G, and electrode 551R. In Figure 4(B), the hole injection / transport layer 104G, the light-emitting layer, and the electron transport layer 108G, which are included in the EL layer 103G, are formed. For example, the EL layer 103G is formed on the sacrificial layer 110B, electrode 551G, and electrode 551R, covering them, using a vacuum deposition method.

[0222] Next, as shown in Figure 4(C), a sacrificial layer 110G is formed on the EL layer 103G, a resist is applied on the sacrificial layer 110G, the resist is formed into a desired shape (resist mask: REG) using photolithography, a portion of the sacrificial layer 110G not covered by the obtained resist mask is removed by etching, after the resist mask is removed, a portion of the EL layer 103G not covered by the sacrificial layer is removed by etching, and the EL layer 103G on electrode 551B and the EL layer 103G on electrode 551R are removed by etching to process into a shape with sides (or exposed sides) or a strip shape extending in a direction intersecting the plane of the paper, as shown in Figure 5(A). If the sacrificial layer 110G has a laminated structure with the first sacrificial layer and the second sacrificial layer, a portion of the second sacrificial layer may be etched with the resist mask, the resist mask may be removed, and a portion of the first sacrificial layer may be etched using the second sacrificial layer as a mask to process the EL layer 103G into a predetermined shape.

[0223] Next, as shown in Figure 5(B), the EL layer 103R is formed on the sacrificial layer 110B, the sacrificial layer 110G, and the electrode 551R. In Figure 5(B), the hole injection / transport layer 104R, the light-emitting layer, and the electron transport layer 108R, which are included in the EL layer 103R, are formed. For example, the EL layer 103R is formed on the sacrificial layer 110B, the sacrificial layer 110G, and the electrode 551R, covering them, using a vacuum deposition method.

[0224] Next, as shown in Figure 5(C), a sacrificial layer 110R is formed on the EL layer 103R, a resist is applied on the sacrificial layer 110R, the resist is formed into a desired shape (resist mask: REG) using photolithography, a portion of the sacrificial layer 110R not covered by the obtained resist mask is removed by etching, a portion of the EL layer 103R not covered by the sacrificial layer 110R is removed by etching, and the EL layer 103R on the electrode 551B and the EL layer 103R on the electrode 551G are removed by etching to process into a shape with sides (or with exposed sides), or a strip shape extending in a direction intersecting the plane of the paper. If the sacrificial layer 110G has a laminated structure with the first sacrificial layer and the second sacrificial layer, a portion of the second sacrificial layer may be etched with the resist mask, the resist mask may be removed, and a portion of the first sacrificial layer may be etched using the second sacrificial layer as a mask to process the EL layer 103G into a predetermined shape. Furthermore, while leaving the sacrificial layers (110B, 110G, 110R) on the EL layers (103B, 103G, 103R), an insulating layer 107 is formed on the sacrificial layers (110B, 110G, 110R) to obtain the shape shown in Figure 6(A).

[0225] For example, the ALD method can be used to form the insulating layer 107. In this case, the insulating layer 107 is formed in contact with the side surfaces of each EL layer (103B, 103G, 103R), as shown in Figure 6(A). This prevents the penetration of oxygen, moisture, and other constituent elements into the interior from the side surfaces of each EL layer (103B, 103G, 103R). As for the material used for the insulating layer 107, for example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, or silicon nitride oxide can be used.

[0226] Next, as shown in Figure 6(B), after removing the sacrificial layers (110B, 110G, 110R), an electron injection layer 109 is formed on the insulating layer (107B, 107G, 107R) and the EL layer (103B, 103G, 103R). The electron injection layer 109 is formed, for example, using a vacuum deposition method. The electron injection layer 109 is formed on the electron transport layer (108B, 108G, 108R). Furthermore, the electron injection layer 109 has a structure in which it is in contact with each EL layer (103B, 103G, 103R) (however, the EL layers (103B, 103G, 103R) shown in Figure 6(B) include hole injection / transport layers (104R, 104G, 104B), an emissive layer, and electron transport layers (108B, 108G, 108R)) via an insulating layer (107B, 107G, 107R) at its side (or end).

[0227] Next, as shown in Figure 6(C), electrodes 552 are formed. Electrodes 552 are formed, for example, using a vacuum deposition method. The electrodes 552 are formed on the electron injection layer 109. The electrodes 552 have a structure that contacts the sides (or edges) of each EL layer (103B, 103G, 103R) (however, the EL layers (103B, 103G, 103R) shown in Figure 6(C) include hole injection / transport layers (104R, 104G, 104B), an emissive layer, and electron transport layers (108B, 108G, 108R)) via the electron injection layer 109 and insulating layers (107B, 107G, 107R). This prevents electrical short circuits between each EL layer (103B, 103G, 103R) and the electrode 552, or more specifically, between the hole injection / transport layers (104B, 104G, 104R) of each EL layer (103B, 103G, 103R) and the electrode 552.

[0228] Through the above process, the EL layers 103B, 103G, and 103R of the light-emitting devices 550B, 550G, and 550R can be separated.

[0229] Furthermore, since the separation process of these EL layers (EL layer 103B, EL layer 103G, and EL layer 103R) is performed using photolithography to form patterns, a high-definition light-emitting device (display panel) can be manufactured. In addition, the edges (sides) of the EL layers processed by photolithography have a shape that is substantially the same surface (or is located substantially on the same plane).

[0230] In EL layers, the hole injection layer, particularly the hole transport region located between the anode and the light-emitting layer, often has high conductivity. Therefore, if it is formed as a common layer for adjacent light-emitting devices, it can cause crosstalk. Consequently, by separating the EL layer using photolithography, as shown in this example configuration, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0231] <Example of configuration of light-emitting device 700 2> The light-emitting device 700 shown in Figure 7 includes light-emitting devices 550B, 550G, 550R, and a partition wall 528. The light-emitting devices 550B, 550G, 550R, and the partition wall 528 are formed on a functional layer 520 provided on a first substrate 510. The functional layer 520 includes drive circuits GD and SD, each composed of multiple transistors, as well as wiring for their electrical connection. These drive circuits are, for example, electrically connected to and capable of driving the light-emitting devices 550B, 550G, and 550R, respectively. The drive circuits GD and SD will be described later in Embodiment 4.

[0232] Furthermore, the light-emitting devices 550B, 550G, and 550R have the device structure shown in Embodiment 2. In particular, Figure 1(A) shows a case where the EL layer 103 in the structure shown differs for each light-emitting device.

[0233] The specific configurations of each light-emitting device shown in Figure 7 are the same as those of light-emitting devices 550B, 550G, and 550R described in Figure 2.

[0234] As shown in Figure 7, the hole injection / transport layers (104B, 104G, 104R) of the EL layers (103B, 103G, 103R) of each light-emitting device (550B, 550G, 550R) are smaller than the other functional layers that make up the EL layer (103B, 103G, 103R) and have a structure covered by the stacked functional layers.

[0235] In this configuration, the hole injection / transport layers (104B, 104G, 104R) in each EL layer are completely isolated by being covered with other functional layers. Therefore, the insulating layers shown in Configuration Example 1 (107B, 107G, 107R in Figure 7) are not necessary to prevent short circuits with electrode 552.

[0236] Furthermore, since each EL layer in this configuration (EL layer 103B, EL layer 103G, and EL layer 103R) is patterned using photolithography during the separation process, the edges (sides) of the processed EL layers have a shape in which they are approximately the same surface (or are located on approximately the same plane).

[0237] Each light-emitting device has an EL layer (EL layer 103B, EL layer 103G, and EL layer 103R) with a gap 580 between adjacent light-emitting devices. Here, if the gap 580 is expressed as SE as the distance between the EL layers of adjacent light-emitting devices, a smaller distance SE allows for a higher aperture ratio and higher resolution. On the other hand, a larger distance SE allows for greater tolerance of manufacturing process variations between adjacent light-emitting devices, thereby increasing the manufacturing yield. Since the light-emitting devices manufactured according to this specification are suitable for miniaturization processes, the distance SE between the EL layers of adjacent light-emitting devices can be 0.5 μm or more and 5 μm or less, preferably 1 μm or more and 3 μm or less, more preferably 1 μm or more and 2.5 μm or less, and even more preferably 1 μm or more and 2 μm or less. Typically, the distance SE is preferably 1 μm or more and 2 μm or less (for example, 1.5 μm or nearby).

[0238] In EL layers, the hole injection layer, particularly the hole transport region located between the anode and the light-emitting layer, often has high conductivity. Therefore, if it is formed as a common layer for adjacent light-emitting devices, it can cause crosstalk. Consequently, by separating the EL layer using photolithography, as shown in this example configuration, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0239] In this specification, devices fabricated using a metal mask or FMM (Fine Metal Mask, a high-resolution metal mask) may be referred to as MM (Metal Mask) structured devices. In addition, in this specification, devices fabricated without using a metal mask or FMM may be referred to as MML (Metal Maskless) structured devices.

[0240] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments.

[0241] (Embodiment 4) In this embodiment, a light-emitting device, which is one aspect of the present invention, will be described using Figures 8(A) to 10(B). The light-emitting device 700 shown in Figures 8(A) to 10(B) has the light-emitting device shown in Embodiment 2. Furthermore, the light-emitting device 700 described in this embodiment can also be called a display panel because it is applicable to the display section of electronic devices and the like.

[0242] As shown in Figure 8(A), the light-emitting device 700 described in this embodiment includes a display area 231, the display area 231 having a pair of pixels 703(i,j). Also, as shown in Figure 8(B), there is a pair of pixels 703(i+1,j) adjacent to the pair of pixels 703(i,j).

[0243] Note that pixel 703(i,j) can contain multiple pixels. For example, multiple pixels displaying colors with different hues can be used. Each of these multiple pixels can be referred to as a subpixel. Alternatively, multiple subpixels can be grouped together and referred to as a single pixel.

[0244] This allows for additive or subtractive color mixing of the colors displayed by the multiple pixels. Alternatively, it enables the display of hues that cannot be displayed by individual pixels.

[0245] Specifically, the pixel 702B(i,j) that displays blue, the pixel 702G(i,j) that displays green, and the pixel 702R(i,j) that displays red can be used as the pixel 703(i,j). In addition, pixels 702B(i,j), 702G(i,j), and 702R(i,j) can each be referred to as subpixels.

[0246] Additionally, a pixel displaying white or the like may be used as pixel 703(i,j) in addition to the above pair. Furthermore, a pixel displaying cyan, a pixel displaying magenta, and a pixel displaying yellow may each be used as a sub-pixel in pixel 703(i,j).

[0247] In addition to the above pair, a pixel that emits infrared light may be used for pixel 703(i,j). Specifically, a pixel that emits light including light with a wavelength of 650 nm to 1000 nm can be used for pixel 703(i,j).

[0248] The display area 231 shown in Figure 8(A) is surrounded by a drive circuit GD and a drive circuit SD. It also has terminals 519 that are electrically connected to the drive circuits GD and SD. Terminals 519 can be electrically connected, for example, to a flexible printed circuit FPC1.

[0249] The drive circuit GD has the function of supplying a first selection signal and a second selection signal. For example, the drive circuit GD is electrically connected to the conductive film G1(i), which will be described later, and supplies the first selection signal, and is electrically connected to the conductive film G2(i), which will be described later, and supplies the second selection signal. The drive circuit SD also has the function of supplying an image signal and a control signal, and the control signal includes a first level and a second level. For example, the drive circuit SD is electrically connected to the conductive film S1g(j), which will be described later, and supplies the image signal, and is electrically connected to the conductive film S2g(j), which will be described later, and supplies the control signal.

[0250] Figure 10(A) shows cross-sectional views of the light-emitting device along the dashed-dotted lines X1-X2 and X3-X4 shown in Figure 8(A). As shown in Figure 10(A), the light-emitting device 700 has a functional layer 520 between the first substrate 510 and the second substrate 770. The functional layer 520 includes the aforementioned drive circuit GD, drive circuit SD, and wiring that electrically connects them. In Figure 10(A), the functional layer 520 is shown to include a pixel circuit 530B(i,j) and a pixel circuit 530G(i,j) and a drive circuit GD, but is not limited to this configuration.

[0251] Furthermore, each pixel circuit of the functional layer 520 (for example, pixel circuits 530B(i,j) and 530G(i,j) shown in Figure 10(A)) is electrically connected to each light-emitting device formed on the functional layer 520 (for example, light-emitting devices 550B(i,j) and 550G(i,j) shown in Figure 10(A)). Specifically, light-emitting device 550B(i,j) is electrically connected to pixel circuit 530B(i,j) via aperture 591B, and light-emitting device 550G(i,j) is electrically connected to pixel circuit 530G(i,j) via aperture 591G. In addition, an insulating layer 705 is provided on the functional layer 520 and each light-emitting device, and the insulating layer 705 has the function of bonding the second substrate 770 and the functional layer 520.

[0252] Furthermore, the second substrate 770 can be a substrate equipped with touch sensors in a matrix. For example, a substrate equipped with a capacitive touch sensor or an optical touch sensor can be used as the second substrate 770. This allows the light-emitting device according to one embodiment of the present invention to be used as a touch panel.

[0253] Furthermore, the specific configuration of the pixel circuit 530G(i,j) is shown in Figure 9(A).

[0254] As shown in Figure 9(A), the pixel circuit 530G(i,j) has switch SW21, switch SW22, transistor M21, capacitor C21, and node N21. The pixel circuit 530G(i,j) also has node N22, capacitor C22, and switch SW23.

[0255] Transistor M21 has a gate electrode electrically connected to node N21, a first electrode electrically connected to light-emitting device 550G(i,j), and a second electrode electrically connected to conductive film ANO.

[0256] Switch SW21 has a first terminal electrically connected to node N21 and a second terminal electrically connected to the conductive film S1g(j). Switch SW21 also has the function of controlling the conduction state or non-conduction state based on the potential of the conductive film G1(i).

[0257] The switch SW22 has a first terminal electrically connected to the conductive film S2g(j), and has the function of controlling the conduction state or non-conduction state based on the potential of the conductive film G2(i).

[0258] Capacitor C21 has a conductive film electrically connected to node N21 and a conductive film electrically connected to the second electrode of switch SW22.

[0259] This allows the image signal to be stored in node N21. Alternatively, the potential of node N21 can be changed using switch SW22. Or, the intensity of the light emitted by the light-emitting device 550G(i,j) can be controlled using the potential of node N21.

[0260] Next, Figure 9(B) shows an example of the specific structure of transistor M21, as explained in Figure 9(A). Note that, as appropriate, a bottom-gate transistor or a top-gate transistor can be used as transistor M21.

[0261] The transistor shown in Figure 9(B) has a semiconductor film 508, a conductive film 504, an insulating film 506, a conductive film 512A, and a conductive film 512B. The transistor is formed, for example, on an insulating film 501C. The transistor also has an insulating film 516 (insulating film 516A and insulating film 516B) and an insulating film 518.

[0262] The semiconductor film 508 has a region 508A that is electrically connected to the conductive film 512A, and a region 508B that is electrically connected to the conductive film 512B. The semiconductor film 508 has a region 508C between regions 508A and 508B.

[0263] The conductive film 504 has a region that overlaps with region 508C, and the conductive film 504 has the function of a gate electrode.

[0264] The insulating film 506 has a region sandwiched between the semiconductor film 508 and the conductive film 504. The insulating film 506 functions as a first gate insulating film.

[0265] The conductive film 512A has either the function of a source electrode or the function of a drain electrode, and the conductive film 512B has either the function of a source electrode or the function of a drain electrode.

[0266] Furthermore, the conductive film 524 can be used in a transistor. The conductive film 524 has a region in which the semiconductor film 508 is sandwiched between it and the conductive film 504. The conductive film 524 functions as a second gate electrode. The insulating film 501D is sandwiched between the semiconductor film 508 and the conductive film 524 and functions as a second gate insulating film.

[0267] The insulating film 516 functions, for example, as a protective film covering the semiconductor film 508. Specifically, the insulating film 516 can include films containing silicon oxide, silicon oxide nitride, silicon nitride, silicon nitride, aluminum oxide, hafnium oxide, yttrium oxide, zirconium oxide, gallium oxide, tantalum oxide, magnesium oxide, lanthanum oxide, cerium oxide, or neodymium oxide.

[0268] The insulating film 518 is preferably made of a material that has the function of suppressing the diffusion of, for example, oxygen, hydrogen, water, alkali metals, alkaline earth metals, etc. Specifically, as the insulating film 518, for example, silicon nitride, silicon oxynitride, aluminum nitride, aluminum oxynitride, etc. are available. Furthermore, it is preferable that the number of nitrogen atoms is greater than the number of oxygen atoms in silicon oxynitride and aluminum oxynitride, respectively.

[0269] Furthermore, in the process of forming the semiconductor film used for the transistors in the pixel circuit, the semiconductor film used for the transistors in the drive circuit can also be formed. For example, a semiconductor film with the same composition as the semiconductor film used for the transistors in the pixel circuit can be used in the drive circuit.

[0270] Furthermore, the semiconductor film 508 can be made of a semiconductor containing elements of Group 14. Specifically, a semiconductor containing silicon can be used for the semiconductor film 508.

[0271] Furthermore, hydrogenated amorphous silicon can be used for the semiconductor film 508. Alternatively, microcrystalline silicon or the like can be used for the semiconductor film 508. This makes it possible to provide a light-emitting device (or display panel) with less display unevenness than, for example, a light-emitting device (or display panel) that uses polysilicon for the semiconductor film 508. Alternatively, it is easier to scale up the light-emitting device.

[0272] Furthermore, polysilicon can be used for the semiconductor film 508. This allows for, for example, a higher field-effect mobility of the transistor compared to a transistor using hydrogenated amorphous silicon for the semiconductor film 508. Alternatively, for example, the driving capability can be increased compared to a transistor using hydrogenated amorphous silicon for the semiconductor film 508. Alternatively, for example, the aperture ratio of the pixels can be improved compared to a transistor using hydrogenated amorphous silicon for the semiconductor film 508.

[0273] Alternatively, for example, the reliability of the transistor can be improved compared to a transistor using hydrogenated amorphous silicon as the semiconductor film 508.

[0274] Alternatively, the temperature required for transistor fabrication can be lowered compared to, for example, transistors using single-crystal silicon.

[0275] Alternatively, the semiconductor film used for the transistors in the drive circuit can be formed using the same process as the semiconductor film used for the transistors in the pixel circuit. Alternatively, the drive circuit can be formed on the same substrate as the substrate on which the pixel circuit is formed. Alternatively, the number of components constituting the electronic device can be reduced.

[0276] Furthermore, single-crystal silicon can be used for the semiconductor film 508. This allows for higher resolution than, for example, a light-emitting device (or display panel) that uses hydrogenated amorphous silicon for the semiconductor film 508. Alternatively, it is possible to provide a light-emitting device with less display unevenness than a light-emitting device that uses polysilicon for the semiconductor film 508. Alternatively, for example, smart glasses or a head-mounted display can be provided.

[0277] Furthermore, a metal oxide can be used for the semiconductor film 508. This allows the pixel circuit to hold the image signal for a longer time compared to a pixel circuit using a transistor with amorphous silicon as the semiconductor film. Specifically, the selection signal can be supplied at a frequency of less than 30 Hz, preferably less than 1 Hz, and more preferably less than once per minute, while suppressing the occurrence of flicker. As a result, fatigue accumulated in the user of the electronic device can be reduced. In addition, power consumption associated with operation can be reduced.

[0278] Furthermore, an oxide semiconductor can be used for the semiconductor film 508. Specifically, an oxide semiconductor containing indium, an oxide semiconductor containing indium, gallium, and zinc, or an oxide semiconductor containing indium, gallium, zinc, and tin can be used for the semiconductor film 508.

[0279] Furthermore, by using an oxide semiconductor as the semiconductor film, it is possible to obtain a transistor with a smaller leakage current in the off state than a transistor using amorphous silicon as the semiconductor film. Therefore, it is preferable to use a transistor using an oxide semiconductor as the semiconductor film for a switch or the like. Moreover, a circuit using a transistor with an oxide semiconductor as the semiconductor film as a switch can maintain the potential of the floating node for a longer time than a circuit using a transistor with an amorphous silicon as the semiconductor film as a switch.

[0280] Figure 10(A) shows a light-emitting device with a structure that extracts light from the second substrate 770 side (top emission type), but as shown in Figure 10(B), a light-emitting device with a structure that extracts light from the first substrate 510 side (bottom emission type) may also be used. In the case of a bottom emission type light-emitting device, the first electrode 101 is formed to function as a semi-transparent / semi-reflective electrode, and the second electrode 102 is formed to function as a reflective electrode.

[0281] Furthermore, although Figures 10(A) and 10(B) describe an active matrix type light-emitting device, the configuration of the light-emitting device shown in Embodiment 2 may also be applied to the passive matrix type light-emitting device shown in Figures 11(A) and 11(B).

[0282] Figure 11(A) is a perspective view showing a passive matrix type light-emitting device, and Figure 11(B) is a cross-sectional view obtained by cutting Figure 11(A) along the X and Y lines. In Figures 11(A) and 11(B), electrodes 952 and 956 are provided on the substrate 951, and an EL layer 955 is provided between electrodes 952 and 956. The ends of electrodes 952 are covered with an insulating layer 953. A partition layer 954 is provided on the insulating layer 953. The side walls of the partition layer 954 have a slope such that the distance between one side wall and the other side wall narrows as it approaches the substrate surface. In other words, the cross-section of the partition layer 954 in the short-side direction is trapezoidal, and the bottom side (the side that faces the same direction as the surface direction of the insulating layer 953 and is in contact with the insulating layer 953) is shorter than the top side (the side that faces the same direction as the surface direction of the insulating layer 953 and is not in contact with the insulating layer 953). In this way, by providing the partition layer 954, it is possible to prevent defects in the light-emitting device caused by static electricity or the like.

[0283] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments.

[0284] (Embodiment 5) In this embodiment, the configuration of an electronic device according to one aspect of the present invention will be explained with reference to Figures 12(A) to 14(B).

[0285] Figures 12(A) to 14(B) illustrate the configuration of an electronic device according to one embodiment of the present invention. Figure 12(A) is a block diagram of the electronic device, and Figures 12(B) to 12(E) are perspective views illustrating the configuration of the electronic device. Figures 13(A) to 13(E) are perspective views illustrating the configuration of the electronic device, and Figures 14(A) and 14(B) are perspective views illustrating the configuration of the electronic device.

[0286] The electronic device 5200B described in this embodiment includes a computing device 5210 and an input / output device 5220 (see Figure 12(A)).

[0287] The arithmetic unit 5210 has a function to receive operation information and a function to supply image information based on the operation information.

[0288] The input / output device 5220 includes a display unit 5230, an input unit 5240, a detection unit 5250, a communication unit 5290, a function for supplying operation information, and a function for supplying image information. Furthermore, the input / output device 5220 also includes a function for supplying detection information, a function for supplying communication information, and a function for receiving communication information.

[0289] The input unit 5240 has the function of supplying operation information. For example, the input unit 5240 supplies operation information based on the operation of the user of the electronic device 5200B.

[0290] Specifically, the input unit 5240 can use a keyboard, hardware buttons, pointing device, touch sensor, illuminance sensor, imaging device, voice input device, eye-tracking device, posture detection device, etc.

[0291] The display unit 5230 has the function of displaying a display panel and image information. For example, the display panel described in Embodiment 2 can be used in the display unit 5230.

[0292] The detection unit 5250 has the function of supplying detection information. For example, it has the function of detecting the surrounding environment in which electronic equipment is being used and supplying it as detection information.

[0293] Specifically, illuminance sensors, imaging devices, posture detection devices, pressure sensors, and human presence sensors can be used in the detection unit 5250.

[0294] The communication unit 5290 has functions for receiving and supplying communication information. For example, it has functions for connecting with other electronic devices or communication networks via wireless or wired communication. Specifically, it has functions such as wireless local area communication, telephone communication, and short-range wireless communication.

[0295] Figure 12(B) shows an electronic device having an external shape that follows a cylindrical column or the like. One example is digital signage. A display panel, which is one aspect of the present invention, can be applied to the display unit 5230. It may also have a function to change the display method according to the illumination of the usage environment. It may also have a function to change the display content when a person is detected. This allows it to be installed, for example, on a building column, or to display advertisements or information.

[0296] Figure 12(C) shows an electronic device that has the function of generating image information based on the trajectory of a pointer used by the user. Examples include electronic whiteboards, electronic bulletin boards, and electronic signboards. Specifically, a display panel with a diagonal length of 20 inches or more, preferably 40 inches or more, and more preferably 55 inches or more can be used. Alternatively, multiple display panels can be arranged to form a single display area. Alternatively, multiple display panels can be arranged to form a multi-screen.

[0297] Figure 12(D) shows an electronic device that can receive information from other devices and display it on the display unit 5230. One example is a wearable electronic device. Specifically, it can display several options, or the user can select several options and send them back to the information sender. Alternatively, it can have a function to change the display method according to the illumination of the usage environment. This can reduce the power consumption of the wearable electronic device, for example. Alternatively, it can display images on the wearable electronic device so that it can be used suitably even in environments with strong ambient light, such as outdoors on a sunny day.

[0298] Figure 12(E) shows an electronic device having a display unit 5230 with a curved surface that gently curves along the side of the housing. One example is a mobile phone. The display unit 5230 includes a display panel, which has the function of displaying on, for example, the front, side, top, and back. This allows information to be displayed not only on the front of the mobile phone, but also on the sides, top, and back.

[0299] Figure 13(A) shows an electronic device that can receive information from the internet and display it on the display unit 5230. One example is a smartphone. For example, a message that has been created can be viewed on the display unit 5230. Alternatively, a message that has been created can be sent to another device. Alternatively, for example, it has a function to change the display method according to the illumination of the usage environment. This can reduce the power consumption of the smartphone. Alternatively, for example, an image can be displayed on the smartphone so that it can be used suitably even in environments with strong ambient light, such as outdoors on a sunny day.

[0300] Figure 13(B) shows an electronic device that can use a remote controller as an input unit 5240. One example is a television system. For example, it can receive information from a broadcasting station or the internet and display it on the display unit 5230. Alternatively, it can photograph the user using the detection unit 5250. Alternatively, it can transmit the user's video. Alternatively, it can acquire the user's viewing history and provide it to a cloud service. Alternatively, it can acquire recommendation information from a cloud service and display it on the display unit 5230. Alternatively, it can display a program or video based on the recommendation information. Alternatively, for example, it has a function to change the display method according to the illumination of the usage environment. This makes it possible to display images on the television system so that it can be used effectively even when strong sunlight shines into the room on a sunny day.

[0301] Figure 13(C) shows an electronic device that can receive educational materials from the internet and display them on the display unit 5230. An example of such a device is a tablet computer. Using the input unit 5240, a report can be entered and sent to the internet. Alternatively, the correction results or evaluations of the report can be obtained from a cloud service and displayed on the display unit 5230. Or, based on the evaluation, suitable educational materials can be selected and displayed.

[0302] For example, the display unit 5230 can receive image signals from other electronic devices and display them. Alternatively, it can be propped up on a stand or the like and used as a sub-display. This allows images to be displayed on the tablet computer in a way that is suitable for use even in environments with strong ambient light, such as outdoors on a sunny day.

[0303] Figure 13(D) shows an electronic device having multiple display units 5230. One example is a digital camera. For example, the display unit 5230 can display an image while the detection unit 5250 is capturing it. Alternatively, the captured image can be displayed on the detection unit. Alternatively, the captured image can be decorated using the input unit 5240. Alternatively, a message can be attached to the captured image. Alternatively, it can be transmitted to the internet. Alternatively, it has a function to change the shooting conditions according to the illumination of the usage environment. This makes it possible to display the subject on the digital camera so that it can be viewed favorably even in environments with strong ambient light, such as outdoors on a sunny day.

[0304] Figure 13(E) shows an electronic device that can control other electronic devices by using the electronic device of this embodiment as a master and using other electronic devices as slaves. One example is a portable personal computer. For example, part of the image information can be displayed on the display unit 5230 and the other part of the image information can be displayed on the display unit of the other electronic device. Alternatively, an image signal can be supplied. Alternatively, information to be written can be obtained from the input unit of the other electronic device using the communication unit 5290. This allows, for example, a portable personal computer to utilize a wide display area.

[0305] Figure 14(A) shows an electronic device having a detection unit 5250 that detects acceleration or direction. An example is a goggle-type electronic device. The detection unit 5250 can supply information relating to the user's position or the direction the user is facing. Alternatively, the electronic device can generate image information for the right eye and image information for the left eye based on the user's position or the direction the user is facing. Alternatively, the display unit 5230 has a display area for the right eye and a display area for the left eye. This allows, for example, the display of an immersive virtual reality space on a goggle-type electronic device.

[0306] Figure 14(B) shows an electronic device having an imaging device and a detection unit 5250 that detects acceleration or direction. An example is a glasses-type electronic device. The detection unit 5250 can supply information relating to the user's position or the direction the user is facing. Alternatively, the electronic device can generate image information based on the user's position or the direction the user is facing. This allows, for example, information to be attached to and displayed on a real-world landscape. Alternatively, images of an augmented reality space can be displayed on the glasses-type electronic device.

[0307] This embodiment can be appropriately combined with other embodiments shown in this specification.

[0308] (Embodiment 6) In this embodiment, a configuration in which the light-emitting device described in Embodiment 2 is used as an illumination device will be explained with reference to Figure 15. Figure 15(A) is a cross-sectional view of the line segment ef in the top view of the illumination device shown in Figure 15(B).

[0309] In this embodiment, the lighting device has a first electrode 401 formed on a translucent substrate 400 which serves as a support. The first electrode 401 corresponds to the first electrode 101 in Embodiment 2. When light is extracted from the first electrode 401 side, the first electrode 401 is formed from a translucent material.

[0310] A pad 412 for supplying voltage to the second electrode 404 is formed on the substrate 400.

[0311] An EL layer 403 is formed on the first electrode 401. The EL layer 403 corresponds to the configuration of the EL layer 103 in Embodiment 2. Please refer to the relevant description for details on these configurations.

[0312] A second electrode 404 is formed by covering the EL layer 403. The second electrode 404 corresponds to the second electrode 102 in Embodiment 2. When light emission is extracted from the first electrode 401 side, the second electrode 404 is formed of a material with high reflectivity. Voltage is supplied to the second electrode 404 by connecting it to the pad 412.

[0313] As described above, the lighting device shown in this embodiment has a light-emitting device having a first electrode 401, an EL layer 403, and a second electrode 404. Since this light-emitting device is a light-emitting device with high luminous efficiency, the lighting device in this embodiment can be a lighting device with low power consumption.

[0314] The lighting device is completed by fixing and sealing the substrate 400, on which the light-emitting device having the above configuration is formed, and the sealing substrate 407 using sealing materials 405 and 406. Either sealing material 405 or 406 may be used. In addition, a desiccant can be mixed into the inner sealing material 406 (not shown in Figure 15(B)), which allows for the adsorption of moisture and leads to improved reliability.

[0315] Furthermore, by extending the pad 412 and a portion of the first electrode 401 outside the sealing materials 405 and 406, it can be used as an external input terminal. Alternatively, an IC chip 420 with a converter or the like may be placed on top of it.

[0316] (Embodiment 7) In this embodiment, an example of an application of a lighting device manufactured by applying a light-emitting device, or a light-emitting device which is a part thereof, which is one aspect of the present invention, will be explained with reference to Figure 16.

[0317] As an indoor lighting device, it can be used as a ceiling light 8001. The ceiling light 8001 is available in both surface-mounted and recessed ceiling types. Such lighting devices are constructed by combining a light-emitting device with a housing or cover. It can also be used as a cord pendant type (suspended from the ceiling by a cord).

[0318] Furthermore, the 8002 footlight illuminates the floor surface, enhancing safety underfoot. For example, it is effective for use in bedrooms, stairwells, or corridors. In such cases, the size or shape can be appropriately changed depending on the size or structure of the room. It can also be configured as a freestanding lighting device consisting of a light-emitting device and a support base.

[0319] Furthermore, the sheet-type lighting 8003 is a thin, sheet-shaped lighting device. Because it is attached to a wall surface, it does not take up much space and can be used in a wide range of applications. It can also be easily made to cover a large area. It can also be used on curved walls or enclosures.

[0320] Alternatively, a lighting device 8004 can be used in which the light from the light source is controlled to flow only in a desired direction.

[0321] Furthermore, the desk lamp 8005 has a light source 8006, and as the light source 8006, a light-emitting device that is a part of the present invention or a light-emitting device that is a part thereof can be applied.

[0322] In addition to the above, by applying a light-emitting device, or a light-emitting device that is a part thereof, according to one aspect of the present invention, to a part of the furniture installed in the room, it is possible to create a lighting device that also functions as furniture.

[0323] As described above, various lighting devices can be obtained by applying a light-emitting device. These lighting devices are included in one aspect of the present invention.

[0324] Furthermore, the configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments.

[0325] (Embodiment 8) In this embodiment, a light-emitting device and a light-receiving device applicable to a display device according to one aspect of the present invention will be described with reference to Figure 28.

[0326] Figure 28(A) shows a schematic cross-sectional view of the light-emitting device 805a and the light-receiving device 805b of a display device 810 according to one aspect of the present invention.

[0327] The light-emitting device 805a has a function of emitting light (hereinafter also referred to as the light-emitting function). The light-emitting device 805a has an electrode 801a, an EL layer 803a, and an electrode 802. Preferably, the light-emitting device 805a is a light-emitting device (organic EL device) that utilizes organic EL as shown in Embodiment 2. Therefore, the EL layer 803a sandwiched between the electrode 801a and the electrode 802 has at least a light-emitting layer. The light-emitting layer has a light-emitting material. By applying a voltage between the electrode 801a and the electrode 802, light is emitted from the EL layer 803a. In addition to the light-emitting layer, the EL layer 803a may have various layers such as a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a carrier (hole or electron) blocking layer, and a charge generation layer. Note that a mixed material according to one aspect of the present invention can be used for the EL layer 803a of the light-emitting device 805a.

[0328] The light-receiving device 805b has a function to detect light (hereinafter also referred to as the light-receiving function). The light-receiving device 805b can be, for example, a pn-type or pin-type photodiode. The light-receiving device 805b has an electrode 801b, a light-receiving layer 803b, and an electrode 802. The light-receiving layer 803b, which is sandwiched between electrodes 801b and 802, has at least an active layer. The light-receiving device 805b functions as a photoelectric conversion device and can generate an electric charge in response to light incident on the light-receiving layer 803b, which can be extracted as an electric current. At this time, a voltage may be applied between electrodes 801b and 802. The amount of charge generated is determined based on the amount of light incident on the light-receiving layer 803b.

[0329] The light-receiving device 805b has the function of detecting visible light. The light-receiving device 805b is sensitive to visible light. It is even more preferable that the light-receiving device 805b has the function of detecting both visible light and infrared light. It is preferable that the light-receiving device 805b is sensitive to both visible light and infrared light.

[0330] In this specification, the wavelength range for blue (B) is defined as 400 nm to less than 490 nm, and blue (B) light is defined as having at least one emission spectral peak in this wavelength range. The wavelength range for green (G) is defined as 490 nm to less than 580 nm, and green (G) light is defined as having at least one emission spectral peak in this wavelength range. The wavelength range for red (R) is defined as 580 nm to less than 700 nm, and red (R) light is defined as having at least one emission spectral peak in this wavelength range. In this specification, the wavelength range for visible light is defined as 400 nm to less than 700 nm, and visible light is defined as having at least one emission spectral peak in this wavelength range. The wavelength range for infrared (IR) is defined as 700 nm to less than 900 nm, and infrared (IR) light is defined as having at least one emission spectral peak in this wavelength range.

[0331] The light-receiving layer 803b of the light-receiving device 805b contains a semiconductor. Examples of such semiconductors include inorganic semiconductors such as silicon, and organic semiconductors containing organic compounds. It is preferable to use an organic semiconductor device (or organic photodiode) as the light-receiving device 805b, in which the light-receiving layer 803b contains an organic semiconductor. Organic photodiodes are easily made thinner, lighter, and larger in area, and offer greater freedom in shape and design, making them applicable to various display devices. Furthermore, using an organic semiconductor allows the EL layer 803a of the light-emitting device 805a and the light-receiving layer 803b of the light-receiving device 805b to be formed using the same method (e.g., vacuum deposition), and common manufacturing equipment can be used, which is preferable. Note that a mixed material, according to one aspect of the present invention, can be used for the light-receiving layer 803b of the light-receiving device 805b.

[0332] In one aspect of the present invention, a display device preferably uses an organic EL device as the light-emitting device 805a and an organic photodiode as the light-receiving device 805b. The organic EL device and the organic photodiode can be formed on the same substrate. Therefore, an organic photodiode can be incorporated into a display device using an organic EL device. In addition to the function of displaying images, the display device according to one aspect of the present invention also has one or both of the functions of imaging and sensing.

[0333] Electrodes 801a and 801b are provided on the same plane. Figure 28(A) shows a configuration in which electrodes 801a and 801b are provided on the substrate 800. Electrodes 801a and 801b can be formed, for example, by processing a conductive film formed on the substrate 800 into island shapes. In other words, electrodes 801a and 801b can be formed through the same process.

[0334] The substrate 800 can be a heat-resistant substrate capable of withstanding the formation of the light-emitting device 805a and the light-receiving device 805b. When an insulating substrate is used as the substrate 800, glass substrates, quartz substrates, sapphire substrates, ceramic substrates, organic resin substrates, etc., can be used. In addition, semiconductor substrates such as single-crystal semiconductor substrates made of silicon or silicon carbide, polycrystalline semiconductor substrates, compound semiconductor substrates such as silicon germanium, and SOI substrates can be used.

[0335] In particular, it is preferable to use a substrate 800 on which a semiconductor circuit including semiconductor elements such as transistors is formed on the aforementioned insulating substrate or semiconductor substrate. It is preferable that the semiconductor circuit constitutes, for example, a pixel circuit, a gate line driving circuit (gate driver), a source line driving circuit (source driver), etc. In addition to the above, an arithmetic circuit, a memory circuit, etc. may also be configured.

[0336] Furthermore, electrode 802 is an electrode made of a layer common to both the light-emitting device 805a and the light-receiving device 805b. Of these electrodes, the electrode that emits light or receives light as an incident electrode preferably uses a conductive film that transmits visible light and infrared light. The electrode that does not emit light or receives light as an incident electrode preferably uses a conductive film that reflects visible light and infrared light.

[0337] In one embodiment of the present invention, the electrode 802 in the display device functions as one of the electrodes of the light-emitting device 805a and the light-receiving device 805b.

[0338] Figure 28(B) shows the case where electrode 801a of the light-emitting device 805a has a higher potential than electrode 802. In this case, electrode 801a functions as the anode of the light-emitting device 805a, and electrode 802 functions as the cathode. Also, electrode 801b of the light-receiving device 805b has a lower potential than electrode 802. In Figure 28(B), to make the direction of current flow clearer, the circuit symbol for the light-emitting diode is shown to the left of the light-emitting device 805a, and the circuit symbol for the photodiode is shown to the right of the light-receiving device 805b. Furthermore, the direction of carrier (electron and hole) flow is schematically indicated by arrows within each device.

[0339] In the configuration shown in Figure 28(B), when a first potential is supplied to electrode 801a via the first wiring, a second potential is supplied to electrode 802 via the second wiring, and a third potential is supplied to electrode 801a via the third wiring in the light-emitting device 805a, the relationship between the magnitudes of each potential is first potential > second potential > third potential.

[0340] Figure 28(C) shows the case where electrode 801a of the light-emitting device 805a has a lower potential than electrode 802. In this case, electrode 801a functions as the cathode of the light-emitting device 805a, and electrode 802 functions as the anode. Also, electrode 801b of the light-receiving device 805b has a lower potential than electrode 802 and a higher potential than electrode 801a. In Figure 28(C), to make the direction of current flow clearer, the circuit symbol for the light-emitting diode is shown to the left of the light-emitting device 805a, and the circuit symbol for the photodiode is shown to the right of the light-receiving device 805b. The direction of carrier (electron and hole) flow is schematically indicated by arrows within each device.

[0341] In the configuration shown in Figure 28(C), when a first potential is supplied to electrode 801a via the first wiring, a second potential is supplied to electrode 802 via the second wiring, and a third potential is supplied to electrode 801a via the third wiring in the light-emitting device 805a, the relationship of the magnitudes of each potential is second potential > third potential > first potential.

[0342] In this embodiment, the resolution of the light-receiving device 805b is 100 ppi or more, preferably 200 ppi or more, more preferably 300 ppi or more, more preferably 400 ppi or more, and even more preferably 500 ppi or more, and can be 2000 ppi or less, 1000 ppi or less, or 600 ppi or less. In particular, by arranging the light-receiving device 805b with a resolution of 200 ppi or more and 600 ppi or less, preferably 300 ppi or more and 600 ppi or less, it can be suitably used for fingerprint imaging. When performing fingerprint authentication using a display device according to one aspect of the present invention, increasing the resolution of the light-receiving device 805b allows for the extraction of fingerprint feature points (Minutia) with high accuracy, for example, thereby improving the accuracy of fingerprint authentication. Furthermore, a resolution of 500 ppi or more is preferable because it allows compliance with standards such as those of the National Institute of Standards and Technology (NIST). Assuming the resolution of the light-receiving device is 500 ppi, each pixel would be 50.8 μm in size, which is sufficient resolution to capture the width of a fingerprint (typically between 300 μm and 500 μm). [Examples]

[0343] In this example, two types of materials were used to create samples with different film structures (single-layer films, multilayer films, mixed films, etc.) by depositing one or two of the materials onto a glass substrate, and heat resistance tests were performed on each sample. The thermal properties of the materials used in this example are shown in Table 1, and their chemical formulas are shown below.

[0344] [Table 1]

[0345] [ka]

[0346] Next, the methods for preparing the samples (Sample 1 to Sample 4) are shown.

[0347] First, a sample layer was formed on a glass substrate using a vacuum deposition apparatus and cut into strips measuring 1 cm x 3 cm. Next, the substrate was placed in a bell jar type heater (Shibata Scientific Co., Ltd. Bell Jar Type Vacuum Oven BV-001), the pressure was reduced to approximately 10 hPa, and then it was fired for 1 hour at a set temperature in the range of 80°C to 150°C.

[0348] Sample 1 is a monolayer film using one type of heteroaromatic compound, formed by depositing 2,9-di(2-naphthyl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen) onto a glass substrate to a thickness of 10 nm.

[0349] Sample 2 is a monolayer film using one type of heteroaromatic compound, formed by depositing 2-[4'-(9-phenyl-9H-carbazole-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviated as 2mpPCBPDBq) onto a glass substrate to a thickness of 10 nm.

[0350] Sample 3 is a multilayer film using multiple heteroaromatic compounds. It was formed by depositing 2mpPCBPDBq at a depth of 10 nm on a glass substrate, followed by depositing NBPhen at a depth of 10 nm.

[0351] Sample 4 is a monolayer film made by mixing multiple heteroaromatic compounds. It was formed by co-depositing 20 nm of 2mpPCBPDBq and NBPhen on a glass substrate in a weight ratio of 0.5:0.5 (=2mpPCBPDBq:NBPhen).

[0352] Each sample prepared using this method was observed visually and with an optical microscope (Olympus Corporation Semiconductor / FPD Inspection Microscope MX61L).

[0353] Figure 17 shows a photograph of the sample prepared in this example (observed under dark-field conditions at 100x magnification).

[0354] The structure of each sample and the results based on Figure 17 are shown in Table 2 below. In Table 2, ○ indicates that no crystals were formed (no crystallization), △ indicates that some crystallization occurred (some crystallization present), and × indicates that crystals were formed (crystallization present).

[0355] [Table 2]

[0356] From the above results, it can be seen that a single film of one type of heteroaromatic compound (Sample 1 NBPhen) does not crystallize up to high temperatures (crystallization begins around 140°C) and can form a thin film with relatively good heat resistance. On the other hand, when it is made into a multilayer film (Sample 3 2mpPCBPDBq\NBPhen), it crystallizes at a low temperature (100°C). In contrast, a single film made by mixing two types of heteroaromatic compounds (Sample 4 2mpPCBPDBq:NBPhen) does not crystallize up to a high temperature (150°C) compared to the multilayer film (Sample 3 2mpPCBPDBq\NBPhen) and the single film (Sample 1 NBPhen). Therefore, it can be seen that a single layer film of a mixed material obtained by mixing multiple heteroaromatic compounds, which is one aspect of the present invention, has the effect of improving the crystallization temperature even if the material crystallizes at a low temperature in the thin film state by mixing. Therefore, it can be seen that a single layer film of a mixed material obtained by mixing multiple heteroaromatic compounds, which is one aspect of the present invention, has dramatically improved heat resistance compared to a single film without mixing.

[0357] Furthermore, in this example, NBPhen and 2mpPCBPDBq, which were formed as single films, crystallized at temperatures lower than the glass transition temperature (Tg) shown in Table 1 for both Sample 1 (NBPhen) and Sample 2 (2mpPCBPDBq), respectively, as shown in Table 2. In other words, by thinning them to a thickness sufficient for forming light-emitting devices or organic semiconductor elements (thinner than 1 μm, for example, organic thin films with a thickness of 1 nm to 100 nm), it is possible to achieve crystallization at temperatures lower than the glass transition temperature, which would not normally occur. Moreover, in Sample 3 (2mpPCBPDBq\NBPhen), which is a multilayer film, crystallization occurred at an even lower temperature (100°C). This confirms that the intermolecular interaction between 2mpPCBPDBq and NBPhen promotes crystallization at temperatures lower than Tg. In contrast, crystallization was not observed in a single film (Sample 4 2mpPCBPDBq:NBPhen) made by mixing two types of heteroaromatic compounds, up to 150°C. This temperature is significantly higher than the glass transition temperature (Tg) of 2mpPCBPDBq. Therefore, a mixed material consisting of multiple heteroaromatic compounds, according to one aspect of the present invention, can suppress the phenomenon of crystallization at a temperature lower than the Tg due to intermolecular interactions in the thin film state, and can maintain a stable glassy state film when thinned. Thus, it has the effect of suppressing crystallization and can be said to be a highly heat-resistant material. By using such a highly heat-resistant thin film, it becomes possible to provide a highly heat-resistant light-emitting device or organic semiconductor element. [Examples]

[0358] In this example, two types of materials were used to create samples with different film structures (single-layer films, multilayer films, mixed films, etc.) by depositing one or two of the materials onto a glass substrate, and heat resistance tests were performed on each sample. The thermal properties of the materials used in this example are shown in Table 3, and their chemical formulas are shown below.

[0359] [Table 3]

[0360] [ka]

[0361] Next, the methods for preparing the samples (Samples 5 to 8) are shown.

[0362] First, a sample layer was formed on a glass substrate using a vacuum deposition apparatus and cut into strips measuring 1 cm x 3 cm. Next, the substrate was placed in a bell jar type heater (Shibata Scientific Co., Ltd. Bell Jar Type Vacuum Oven BV-001), the pressure was reduced to approximately 10 hPa, and then it was fired for 1 hour at a set temperature in the range of 80°C to 150°C.

[0363] Sample 5 is a monolayer film using one type of heteroaromatic compound, formed by depositing 2,9-di(2-naphthyl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen) onto a glass substrate to a thickness of 10 nm.

[0364] Sample 6 is a monolayer film using one type of heteroaromatic compound, formed by depositing 8-(1,1'-biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofl[3,2-d]pyrimidine (abbreviated as 8BP-4mDBtPBfpm) onto a glass substrate to a thickness of 10 nm.

[0365] Sample 7 is a multilayer film using multiple heteroaromatic compounds. It was formed by depositing 10 nm of 8BP-4mDBtPBfpm onto a glass substrate, followed by depositing 10 nm of NBPhen.

[0366] Sample 8 is a monolayer film made by mixing multiple heteroaromatic compounds. It was formed on a glass substrate by co-depositing 8BP-4mDBtPBfpm and NBPhen in a weight ratio of 0.5:0.5 (=8BP-4mDBtPBfpm:NBPhen) to a thickness of 20 nm.

[0367] Each sample prepared using this method was observed visually and with an optical microscope (Olympus Corporation Semiconductor / FPD Inspection Microscope MX61L).

[0368] Figure 18 shows a photograph of the sample prepared in this example (observed under dark-field conditions at 100x magnification).

[0369] The structure of each sample and the results based on Figure 18 are shown in Table 4 below. In Table 4, ○ indicates that no crystals were formed (no crystallization), △ (white triangle) indicates that some crystallization occurred (some crystallization present), × indicates that crystals were formed (crystallization present), and ▲ (black triangle) indicates that only the edges were crystallized (crystallization only on the edges).

[0370] [Table 4]

[0371] From the above results, it can be seen that a single film of one type of heteroaromatic compound (Sample 5 NBPhen) does not crystallize up to high temperatures (crystallization begins around 140°C) and can form a thin film with relatively good heat resistance. On the other hand, when it is made into a multilayer film (Sample 7 8BP-4mDBtPBfpm\NBPhen), the entire film crystallizes at a low temperature (80°C). In contrast, in a single film (mixed film) made by mixing two types of heteroaromatic compounds (Sample 8 8BP-4mDBtPBfpm:NBPhen), crystallization was observed only at the edges from around 100°C, but even when the heat resistance test temperature was increased, crystallization did not progress to the entire film. Therefore, it can be seen that a mixed film obtained by mixing multiple heteroaromatic compounds, which is one aspect of the present invention, has the effect of improving the crystallization temperature even if the material crystallizes at low temperatures in the thin film state by mixing. Therefore, it can be seen that a mixed film obtained by mixing multiple heteroaromatic compounds, which is one aspect of the present invention, has dramatically improved heat resistance compared to a multilayer film.

[0372] Furthermore, as shown in Table 4, sample 5 (NBPhen), a single film, crystallized at a temperature lower than the glass transition temperature (Tg) shown in Table 3. However, sample 6 (8BP-4mDBtPBfpm), also a single film, did not crystallize even at temperatures higher than Tg. However, in sample 7 (8BP-4mDBtPBfpm\NBPhen), a multilayer film, the entire film crystallized at a temperature (80°C) lower than the Tg of the single films (samples 5 and 6). This confirmed that the intermolecular interaction between 8BP-4mDBtPBfpm and NBPhen promoted crystallization at temperatures lower than Tg. In contrast, sample 8 (8BP-4mDBtPBfpm:NBPhen), a single film made by mixing two types of heteroaromatic compounds, showed crystallization only at the edges from around 100°C, and it was found that crystallization did not progress across the entire film even when the heat resistance test temperature was increased. Therefore, a mixed material comprising multiple heteroaromatic compounds, according to one aspect of the present invention, can suppress the phenomenon of crystallization at a temperature lower than the Tg due to intermolecular interactions in the thin film state, and can maintain a stable glassy state film when thinned. Thus, it has the effect of suppressing crystallization and can be said to be a material with high heat resistance. By using such a highly heat-resistant thin film, it becomes possible to provide a highly heat-resistant light-emitting device or organic semiconductor element. [Examples]

[0373] In this example, two types of materials were used to create samples with different film structures (single-layer films, multilayer films, mixed films, etc.) by depositing one or two of the materials onto a glass substrate, and heat resistance tests were performed on each sample. The thermal properties of the materials used in this example are shown in Table 5, and their chemical formulas are shown below.

[0374] [Table 5]

[0375] [ka]

[0376] Next, the methods for preparing the samples (Samples 9 to 12) are shown.

[0377] First, a sample layer was formed on a glass substrate using a vacuum deposition apparatus and cut into strips measuring 1 cm x 3 cm. Next, the substrate was placed in a bell jar type heater (Shibata Scientific Co., Ltd. Bell Jar Type Vacuum Oven BV-001), the pressure was reduced to approximately 10 hPa, and then it was fired for 1 hour at a set temperature in the range of 80°C to 150°C.

[0378] Sample 9 is a monolayer film using one type of heteroaromatic compound, formed by depositing 2,2'-(pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviated as 2,6(P-Bqn)2Py) onto a glass substrate to a thickness of 10 nm.

[0379] Sample 10 is a monolayer film using one type of heteroaromatic compound, formed by depositing 8-(1,1'-biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofl[3,2-d]pyrimidine (abbreviated as 8BP-4mDBtPBfpm) onto a glass substrate to a thickness of 10 nm.

[0380] Sample 11 is a multilayer film using multiple heteroaromatic compounds. It was formed by depositing 8BP-4mDBtPBfpm at a depth of 10 nm on a glass substrate, followed by depositing 2,6(P-Bqn)2Py at a depth of 10 nm.

[0381] Sample 12 is a monolayer film made by mixing multiple heteroaromatic compounds. It was formed by co-depositing 8BP-4mDBtPBfpm and 2,6(P-Bqn)2Py on a glass substrate in a weight ratio of 0.5:0.5 (=8BP-4mDBtPBfpm:2,6(P-Bqn)2Py) to a thickness of 20 nm.

[0382] Each sample prepared using this method was observed visually and with an optical microscope (Olympus Corporation Semiconductor / FPD Inspection Microscope MX61L).

[0383] Figure 19 shows a photograph of the sample prepared in this example (observed under dark-field conditions at 100x magnification).

[0384] The structure of each sample and the results based on Figure 19 are shown in Table 6 below. In Table 6, ○ indicates that no crystals were formed (no crystallization), △ (white triangle) indicates that some crystallization occurred (some crystallization present), × indicates that crystals were formed (crystallization present), and ▲ (black triangle) indicates that only the edges were crystallized (crystallization only on the edges).

[0385] [Table 6]

[0386] From the above results, it can be seen that a single film of one type of heteroaromatic compound (Sample 9 2,6(P-Bqn)2Py) does not crystallize up to high temperatures (crystallization begins around 110°C) and can form a thin film with relatively good heat resistance. On the other hand, when it is made into a multilayer film (Sample 11 8BP-4mDBtPBfpm\2,6(P-Bqn)2Py), the entire film crystallizes at a low temperature (80°C). In contrast, in a single film made by mixing two types of heteroaromatic compounds (Sample 12 8BP-4mDBtPBfpm:2,6(P-Bqn)2Py), crystallization was observed only at the edges from around 100°C, but even when the heat resistance test temperature was increased, crystallization did not progress to the entire film. Therefore, it can be seen that a single layer film of a mixed material obtained by mixing multiple heteroaromatic compounds, which is one aspect of the present invention, has the effect of improving the crystallization temperature even if the material crystallizes at a low temperature in the thin film state by mixing. Therefore, it can be seen that a single-layer film of a mixed material obtained by mixing a plurality of heteroaromatic compounds, according to one aspect of the present invention, exhibits dramatically improved heat resistance compared to a multilayer film.

[0387] Furthermore, in this example, the 2,6(P-Bqn)2Py and 8BP-4mDBtPBfpm used were formed as single films. In the results shown in Table 6 for sample 9 (2,6(P-Bqn)2Py) and sample 10 (8BP-4mDBtPBfpm), respectively, the glass transition temperature (Tg) shown in Table 5 was not observed for 2,6(P-Bqn)2Py, but crystallization was confirmed from 110°C. Crystallization was not observed for 8BP-4mDBtPBfpm even at temperatures higher than its Tg. However, in the case of the multilayer film Sample 11 (8BP-4mDBtPBfpm\2,6(P-Bqn)2Py), crystallization occurred across the entire film at a lower temperature (80°C) than in the single films (Sample 9, Sample 10). This confirmed that crystallization was promoted even at temperatures lower than Tg due to the intermolecular interaction between 2,6(P-Bqn)2Py and 8BP-4mDBtPBfpm. In contrast, in the single film (Sample 12 8BP-4mDBtPBfpm:2,6(P-Bqn)2Py) made by mixing two types of heteroaromatic compounds, crystallization was observed only at the edges from around 100°C, and it was found that crystallization did not progress across the entire film even when the heat resistance test temperature was increased. Therefore, a mixed material consisting of multiple heteroaromatic compounds, which is one aspect of the present invention, can suppress the phenomenon of crystallization at temperatures lower than Tg due to intermolecular interactions in the thin film state, and can maintain a stable glassy state film when thinned. Thus, it can be said that it has the effect of suppressing crystallization and is a highly heat-resistant material. By using a thin film with such high heat resistance, it becomes possible to provide a light-emitting device or organic semiconductor element with high heat resistance. [Examples]

[0388] From the results of Example 1, it was found that the heat resistance of the heteroaromatic compound and organic compound used in the electron transport layer of a light-emitting device according to one aspect of the present invention is improved when they are mixed into a film compared to a laminated film made by stacking single layers of these compounds. Therefore, a light-emitting device 1 using a mixed film of a heteroaromatic compound and an organic compound in the electron transport layer, and a comparative light-emitting device 1 using a laminated film of a heteroaromatic compound and an organic compound were fabricated, and the characteristics of each device were compared. The device structure and its characteristics are described below. The specific configurations of the light-emitting device 1 and comparative light-emitting device 1 used in this example are shown in Table 7. The chemical formulas of the materials used in this example are shown below.

[0389] [Table 7]

[0390] [ka]

[0391] <Fabrication of Light-Emitting Device 1> As shown in Figure 20, the light-emitting device 1 in this embodiment has a structure in which a hole injection layer 911, a hole transport layer 912, a light-emitting layer 913, an electron transport layer 914, and an electron injection layer 915 are sequentially stacked on a first electrode 901 formed on a substrate 900, and a second electrode 903 is stacked on the electron injection layer 915.

[0392] First, a first electrode 901 was formed on the substrate 900. The electrode area was 4 mm². 2 The dimensions were set to (2mm x 2mm). A glass substrate was used for substrate 900. The first electrode 901 was formed by sputtering indium tin oxide (ITSO) containing silicon oxide to a thickness of 70 nm.

[0393] Here, as a pretreatment, the surface of the substrate was washed with water, baked at 200°C for 1 hour, and then subjected to UV ozone treatment for 370 seconds. After that, 10 -4The substrate was introduced into a vacuum deposition apparatus where the internal pressure was reduced to approximately Pa. After vacuum firing at 170°C for 60 minutes in the heating chamber of the vacuum deposition apparatus, the substrate was allowed to cool for about 30 minutes.

[0394] Next, a hole injection layer 911 was formed on the first electrode 901. The hole injection layer 911 was deposited in a vacuum deposition apparatus. -4 After reducing the pressure to Pa, N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as PCBBiF), represented by the above structural formula (i), and an electron acceptor material (OCHD-003) containing fluorine with a molecular weight of 672 were co-deposited at a weight ratio of 1:0.03 (=PCBBiF:OCHD-003) to form a 10 nm layer.

[0395] Next, a hole transport layer 912 was formed on the hole injection layer 911. The hole transport layer 912 was formed by depositing PCBBiF at a 50 nm thickness.

[0396] Next, a light-emitting layer 913 was formed on the hole transport layer 912.

[0397] The light-emitting layer 913 was formed by co-depositing 2-[4'-(9-phenyl-9H-carbazole-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviated as 2mpPCBPDBq), represented by the above structural formula (ii), PCBBiF, and tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviated as Ir(tBuppm)3), represented by the above structural formula (iii), at a weight ratio of 2mpPCBPDBq:PCBBiF:Ir(tBuppm)3 = 0.8:0.2:0.05 at a thickness of 50 nm.

[0398] Next, an electron transport layer 914 was formed on the light-emitting layer 913. The electron transport layer 914 was formed by co-depositing 2mpPCBPDBq, represented by the above structural formula (iv), and 2,9-di(2-naphthyl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen) at a weight ratio of 2mpPCBPDBq:NBPhen = 1:1 over a 30 nm layer.

[0399] Next, an electron injection layer 915 was formed on the electron transport layer 914. The electron injection layer 915 was formed by depositing lithium fluoride (LiF) to a thickness of 1 nm.

[0400] Next, a second electrode 903 was formed on the electron injection layer 915. The second electrode 903 was formed by vapor deposition of aluminum to a thickness of 200 nm. In this embodiment, the second electrode 903 functions as a cathode.

[0401] Through the above steps, a light-emitting device 1 was formed on a substrate 900, comprising an EL layer sandwiched between a pair of electrodes. The hole injection layer 911, hole transport layer 912, light-emitting layer 913, electron transport layer 914, and electron injection layer 915 described in the above steps are functional layers constituting the EL layer in one embodiment of the present invention. Furthermore, in the deposition steps of the above-described manufacturing method, a deposition method using resistance heating was employed for all steps.

[0402] The fabricated light-emitting device 1 was sealed in a glove box under a nitrogen atmosphere to prevent exposure to the air (sealant was applied around the element, UV treatment was performed during sealing, and heat treatment was performed at 80°C for 1 hour).

[0403] <Fabrication of comparative light-emitting device 1> Comparative light-emitting device 1 was fabricated in the same way as light-emitting device 1, by first depositing 2mpPCBPDBq and NBPhen as the electron transport layer 914, then depositing 2mpPCBPDBq at a 10 nm layer, followed by 20 nm of NBPhen.

[0404] <<Operating characteristics of light-emitting device 1>> Figure 21 shows the luminance-current density characteristics of light-emitting device 1 and comparative light-emitting device 1, Figure 22 shows the current efficiency-luminance characteristics, Figure 23 shows the luminance-voltage characteristics, Figure 24 shows the current-voltage characteristics, Figure 25 shows the external quantum efficiency-luminance characteristics, and Figure 26 shows the emission spectra. Furthermore, the luminance characteristics of light-emitting device 1 and comparative light-emitting device 1 at 1000 cd / m² are also shown. 2 Table 8 shows the main characteristics of the vicinity. Brightness, CIE chromaticity, and emission spectrum were measured using a spectroradiometer (Topcon SR-UL1R) at room temperature.

[0405] [Table 8]

[0406] The results shown in Figures 21 to 26 and Table 8 indicate that the light-emitting device 1, which is one embodiment of the present invention, exhibits operating characteristics equivalent to those of the comparative light-emitting device 1.

[0407] Next, reliability tests were performed on each light-emitting device. The results of the reliability tests for light-emitting device 1 and comparative light-emitting device 1 are shown in Figure 27. In Figure 27, the vertical axis represents the normalized brightness (%) with the initial brightness set to 100%, and the horizontal axis represents the device's operating time (h). For the reliability test, each light-emitting device was subjected to a 50 mA / cm² test. 2 A drive test was conducted at a constant current density.

[0408] The results shown in Figure 27 demonstrate that the light-emitting device 1, which is one embodiment of the present invention, has good reliability comparable to that of the comparative light-emitting device. [Examples]

[0409] This example describes the synthesis method of 2-[4'-(9-phenyl-9H-carbazole-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviated as 2mpPCBPDBq), which was used in Examples 1 and 2. The structural formula of 2mpPCBPDBq is shown below.

[0410] [ka]

[0411] ≪Synthesis of 2mpPCBPDBq≫ 81.8 g (0.24 mol) of 2-(3-chlorophenyl)dibenzo[f,h]quinoxaline, 95.6 g (0.26 mol) of 4-(9-phenyl-9H-carbazole-3-yl)phenylboronic acid, 109 g (0.72 mmol) of cesium fluoride, and 1.2 L of mesitylene were placed in a 3 L three-necked flask, then degassed under reduced pressure, and the system was subjected to a nitrogen stream. To this mixture, 0.66 g (7.2 mmol) of tris(dibenzylideneacetone)dipalladium(0)(Pd2(dba)3) and 5.2 g (14.4 mmol) of 2'-(dicyclohexylphosphino)acetophenone ethylene ketal were added, and the mixture was stirred at 120 °C for 3 hours.

[0412] After stirring, the resulting mixture was cooled to room temperature, and then 1 L of ethanol was added and the mixture was stirred for 15 hours. After stirring, the precipitated solid was collected by suction filtration, washed with 2 L of water, collected again by suction filtration, and washed with water and ethanol. The obtained solid was dried and then subjected to suction filtration through Celite (Wako Pure Chemical Industries, Ltd., catalog number: 537-02305) and alumina using 5 L of hot toluene, followed by drying to obtain 127 g of the target white powder (yield: 87%). The synthesis scheme is shown in the following formula (a-1).

[0413] [ka]

[0414] The obtained solid was purified by sublimation using the train sublimation method. Sublimation purification was performed by heating 118 g of the obtained solid at 380°C for 15 hours. The pressure during sublimation purification was 0.83 Pa and the argon flow rate was 100 sccm. After sublimation purification, 102 g of the target solid was obtained with a recovery rate of 87%.

[0415] Nuclear magnetic resonance spectroscopy of the solid obtained above ( 1 The results of the analysis by 1H-NMR are shown below. From these results, it was found that 2mpPCBPDBq was obtained in this example.

[0416] 1 H-NMR (chloroform-d, 500MHz): δ=7.32-7.35(m,1H),7.446(s,1H),7.454(s,1H ),7.49-7.53(m,2H),7.61-7.66(m,4H),7.71-7.92(m,11H),8.24(d,J=8.0H z,1H),8.33(d,J=8.0Hz,1H),8.46(sd,J=1.0Hz,1H),8.67-8.68(m,3H),9.2 6(dd,J=7.8Hz, J=1.3Hz,1H),9.47(dd,J=8.0Hz,J=1.5Hz,1H),9.48(s,1H). [Explanation of symbols]

[0417] 101 First electrode 102 Second electrode 103a EL layer 103B EL layer 103b EL layer 103G EL layer 103R EL layer 103 EL layer 104B Transport layer 104G transport layer 104R transport layer 106 Charge generation layer 107B Insulating layer 107G insulating layer 107R Insulating layer 107 Insulating layer 108B Electron transport layer 108G electron transport layer 108R Electron transport layer 109 Electron injection layer 110B Sacrifice Layer 110G Sacrificial Layer 110R Sacrifice Layer 111a Hole injection layer 111b Hole injection layer 111 Hole injection layer 112a Hole transport layer 112b Hole transport layer 112 Hole transport layer 113a Light-emitting layer 113b Emitting layer 113c emissive layer 113 Emitting layer 114b Electron transport layer 114 Electron transport layer 115b Electron injection layer 115 Electron injection layer 130 Connection part 231 Display area 400 circuit boards 401 First electrode 403 EL layer 404 Second electrode 405 sealant 406 Sealant 407 Sealing substrate 412 pads 420 IC chips 501C insulating film 501D insulating film 504 Conductive film 506 Insulating film 508A area 508B area 508C area 508 Semiconductor film 510 First substrate 512A Conductive film 512B Conductive film 516A insulating film 516B insulating film 516 Insulating film 518 Insulating Film 519 terminals 520 Functional Layers 524 Conductive film 528 Bulkhead 530B Pixel Circuit 530G Pixel Circuit 550B Light-Emitting Device 550G Light-emitting Device 550R Light-Emitting Device 551B Electrode 551C connecting electrode 551G electrode 551R electrode 552 Electrode 580 Gap 591B opening 591G opening 700 Light-emitting devices 702B pixels 702G pixels 702R pixels 703 pixels 705 Insulating layer 770 Second circuit board 800 circuit boards 801a electrode 801b electrode 802 Electrode 803a EL layer 803b Photosensitive layer 805a Light-emitting device 805b Light receiving device 810 Display device 900 circuit boards 901 First electrode 903 Second electrode 911 Hole injection layer 912 Hole transport layer 913 Emitting layer 914 Electron transport layer 915 Electron injection layer 951 circuit board 952 Electrode 953 Insulating layer 954 Partition layer 955 EL layer 956 Electrode 5200B Electronic equipment 5210 Arithmetic unit 5220 Input / Output Device 5230 Display section 5240 Input Section 5250 Detection Unit 5290 Communications Department 8001 Ceiling Light 8002 Footlight 8003 Sheet-type lighting 8004 Lighting device 8005 Desk Lamp 8006 light source

Claims

1. A first heteroaromatic compound and a second heteroaromatic compound, The first heteroaromatic compound is a mixed material represented by any one of general formulas (G1) to (G6). (However, the second heteroaromatic compound is not represented by the same general formula as the first heteroaromatic compound.) 【Chemistry 1】 (In formula (G1), A １ represents any one of a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted benzonaphthothiophenyl group, a substituted or unsubstituted dinaphthothiophenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted benzonaphthofuranyl group, and a substituted or unsubstituted dinaphthofuranyl group; R １１ ~R １９ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms; Ar １ represents an arylene group having 6 to 30 carbon atoms, the arylene group may have substituents, and the substituents may be bonded to each other to form a ring. In addition, in the above formula (G2), R ５１ ~R ５８ each independently represents any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms, and a substituted or unsubstituted heterocycle having 1 to 6 carbon atoms. In addition, in the above formula (G3), A ２ represents a substituent having 3 to 30 carbon atoms containing an aromatic ring or a heteroaromatic ring. ８１ ~R ８７ each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms; n is 2 or 3. In addition, in the above formula (G4), R １０１ and R １０２ each independently represents hydrogen or a group having a total of 1 to 100 carbon atoms; R １０１ and R １０２ At least one of the above has a substituent containing any one of a pyrrole ring structure, a furan ring structure, and a thiophene ring structure, via a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenylene group. In addition, in the above formula (G5), Ar ２ , Ar ３ , Ar ４ , and Ar ５ each independently represents a substituted or unsubstituted aromatic hydrocarbon ring, the substituent of the aromatic hydrocarbon ring is any one of an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, and a cyano group, and the number of carbon atoms forming the aromatic hydrocarbon ring is 6 to 25. m and n are each 0 or 1. １０３ and R １０４ each independently represents hydrogen or a group having a total of 1 to 100 carbon atoms; R １０３ and R １０４ At least one of the above has a substituent containing any one of a pyrrole ring structure, a furan ring structure, and a thiophene ring structure, via a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenylene group. In addition, in the above formula (G6), Ar ２ , Ar ３ , Ar ４ , and Ar ５ each independently represents a substituted or unsubstituted aromatic hydrocarbon ring, the substituent of the aromatic hydrocarbon ring is any one of an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, and a cyano group, and the number of carbon atoms forming the aromatic hydrocarbon ring is 6 to 25. m and n are each 0 or 1. １０５ and R １０６ each independently represents hydrogen or a group having a total of 1 to 100 carbon atoms; R １０５ and R １０６ At least one of has a substituent containing any one of a pyrrole ring structure, a furan ring structure, and a thiophene ring structure via a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenylene group.

2. A first heteroaromatic compound and a second heteroaromatic compound, The first heteroaromatic compound is a mixed material represented by any one of general formulas (G1-1) to (G6-1). (However, the second heteroaromatic compound is not represented by the same general formula as the first heteroaromatic compound.) 【Chemistry 2】 In formula (G1-1), Z represents nitrogen, oxygen, or sulfur; R １１ ~R １９ and R ２１ ~R ２８ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms; Ar １ represents an arylene group having 6 to 30 carbon atoms. However, when Z represents nitrogen, or R ２１ ~R ２８ Any one of the following is Ar １ The arylene group may have a substituent, and the substituents may be bonded to each other to form a ring. In addition, in the above formula (G2-1), R ５１ ~R ５８ each independently represents any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted aryl group having 6 to 14 carbon atoms, a substituted or unsubstituted heteroaryl group having 1 to 15 carbon atoms, and a substituted or unsubstituted heterocycle having 1 to 6 carbon atoms. In addition, in the above formula (G3-1), A ２ represents a substituted or unsubstituted aromatic or heteroaromatic ring-containing substituent having 3 to 30 carbon atoms. ８１ represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms. In the above formula (G4-1), Q represents oxygen or sulfur, R ２００ represents any one of 1 to 3 substituents; R ２０１ represents any one of 1 to 4 substituents; R 200 and R 201 each independently represent any one of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms; R ２００ When R is 2 or 3, ２０１ When is 2 to 4, they may be the same or different. In the above formula (G5-1), Q represents oxygen or sulfur; ４ and Ar ５ each independently represents a substituted or unsubstituted aromatic hydrocarbon ring, the substituent of the aromatic hydrocarbon ring is any one of an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, and a cyano group, and the number of carbon atoms forming the aromatic hydrocarbon ring is 6 to 30. ６ represents an arylene group having 6 to 13 carbon atoms, the arylene group may have a substituent, and the substituents may be bonded to each other to form a ring. q is 0 or 1. ２００ represents any one of 1 to 3 substituents; R ２０１ represents any one of 1 to 4 substituents, and R 200 and R 201 each independently represent any one of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms. In addition, in formula (G6-1), Q represents oxygen or sulfur; ４ and Ar ５ each independently represents a substituted or unsubstituted aromatic hydrocarbon ring, the substituent of the aromatic hydrocarbon ring is any one of an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, and a cyano group, and the number of carbon atoms forming the aromatic hydrocarbon ring is 6 to 30. ６ represents an arylene group having 6 to 13 carbon atoms, the arylene group may have a substituent, and the substituents may be bonded to each other to form a ring. q is an integer of 0 to 4. ２００ represents any one of 1 to 3 substituents; R ２０１ represents any one of 1 to 4 substituents, and R 200 and R 201 each independently represent any one of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms.

3. A first heteroaromatic compound and a second heteroaromatic compound, The first heteroaromatic compound and the second heteroaromatic compound are mixed materials each represented by any one of General Formulas (G1) to (G6) and each having a different molecular structure. 【Chemistry 3】 (In formula (G1), A １ represents any one of a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted benzonaphthothiophenyl group, a substituted or unsubstituted dinaphthothiophenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted benzonaphthofuranyl group, and a substituted or unsubstituted dinaphthofuranyl group; R １１ ~R １９ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms; Ar １ represents an arylene group having 6 to 30 carbon atoms, the arylene group may have substituents, and the substituents may be bonded to each other to form a ring. In addition, in the above formula (G2), R ５１ ~R ５８ each independently represents any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms, and a substituted or unsubstituted heterocycle having 1 to 6 carbon atoms. In addition, in the above formula (G3), A ２ represents a substituent having 3 to 30 carbon atoms containing an aromatic ring or a heteroaromatic ring. ８１ ~R ８７ each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms; n is 2 or 3. In addition, in the above formula (G4), R １０１ and R １０２ each independently represents hydrogen or a group having a total of 1 to 100 carbon atoms; R １０１ and R １０２ At least one of the above has a substituent containing any one of a pyrrole ring structure, a furan ring structure, and a thiophene ring structure, via a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenylene group. In addition, in the above formula (G5), Ar ２ , Ar ３ , Ar ４ , and Ar ５ each independently represents a substituted or unsubstituted aromatic hydrocarbon ring, the substituent of the aromatic hydrocarbon ring is any one of an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, and a cyano group, and the number of carbon atoms forming the aromatic hydrocarbon ring is 6 to 25. m and n are each 0 or 1. １０３ and R １０４ each independently represents hydrogen or a group having a total of 1 to 100 carbon atoms; R １０３ and R １０４ At least one of the above has a substituent containing any one of a pyrrole ring structure, a furan ring structure, and a thiophene ring structure, via a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenylene group. In addition, in the above formula (G6), Ar ２ , Ar ３ , Ar ４ , and Ar ５ each independently represents a substituted or unsubstituted aromatic hydrocarbon ring, the substituent of the aromatic hydrocarbon ring is any one of an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, and a cyano group, and the number of carbon atoms forming the aromatic hydrocarbon ring is 6 to 25. m and n are each 0 or 1. １０５ and R １０６ each independently represents hydrogen or a group having a total of 1 to 100 carbon atoms; R １０５ and R １０６ At least one of has a substituent containing any one of a pyrrole ring structure, a furan ring structure, and a thiophene ring structure via a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenylene group.

4. A first heteroaromatic compound and a second heteroaromatic compound, The first heteroaromatic compound and the second heteroaromatic compound are mixed materials each represented by any one of general formulas (G1-1) to (G6-1) and each having a different molecular structure. 【Chemistry 4】 In formula (G1-1), Z represents nitrogen, oxygen, or sulfur; R １１ ~R １９ and R ２１ ~R ２８ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms; Ar １ represents an arylene group having 6 to 30 carbon atoms. However, when Z represents nitrogen, or R ２１ ~R ２８ Any one of the following is Ar １ The arylene group may have a substituent, and the substituents may be bonded to each other to form a ring. In addition, in the above formula (G2-1), R ５１ ~R ５８ each independently represents any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted aryl group having 6 to 14 carbon atoms, a substituted or unsubstituted heteroaryl group having 1 to 15 carbon atoms, and a substituted or unsubstituted heterocycle having 1 to 6 carbon atoms. In addition, in the above formula (G3-1), A ２ represents a substituted or unsubstituted aromatic or heteroaromatic ring-containing substituent having 3 to 30 carbon atoms. ８１ represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms. In the above formula (G4-1), Q represents oxygen or sulfur, R ２００ represents any one of 1 to 3 substituents; R ２０１ represents any one of 1 to 4 substituents; R 200 and R 201 each independently represent any one of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms; R ２００ When R is 2 or 3, ２０１ When is 2 to 4, they may be the same or different. In the above formula (G5-1), Q represents oxygen or sulfur; ５ each independently represents a substituted or unsubstituted aromatic hydrocarbon ring, the substituent of the aromatic hydrocarbon ring is any one of an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, and a cyano group, and the number of carbon atoms forming the aromatic hydrocarbon ring is 6 to 30. ６ represents an arylene group having 6 to 13 carbon atoms, the arylene group may have a substituent, and the substituents may be bonded to each other to form a ring. q is 0 or 1. ２００ represents any one of 1 to 3 substituents; R ２０１ represents any one of 1 to 4 substituents, and R 200 and R 201 each independently represent any one of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms. In addition, in formula (G6-1), Q represents oxygen or sulfur; ４ and Ar ５ each independently represents a substituted or unsubstituted aromatic hydrocarbon ring, the substituent of the aromatic hydrocarbon ring is any one of an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a monocyclic saturated hydrocarbon group having 5 to 7 carbon atoms, a polycyclic saturated hydrocarbon group having 7 to 10 carbon atoms, and a cyano group, and the number of carbon atoms forming the aromatic hydrocarbon ring is 6 to 30. ６ represents an arylene group having 6 to 13 carbon atoms, the arylene group may have a substituent, and the substituents may be bonded to each other to form a ring. q is an integer of 0 to 4. ２００ represents any one of 1 to 3 substituents; R ２０１ represents any one of 1 to 4 substituents, and R 200 and R 201 each independently represent any one of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and a substituted or unsubstituted aromatic hydrocarbon group having 6 to 13 carbon atoms.

5. A first heteroaromatic compound and a second heteroaromatic compound, The first heteroaromatic compound and the second heteroaromatic compound are each represented by any one of structural formulas (101) to (108), and are mixed materials having different molecular structures. 【Chemistry 5】

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