Light-emitting device, light-emitting apparatus, electronic appliance, and lighting apparatus

Abstract

To provide a light-emitting device having high luminous efficiency.SOLUTION: The light-emitting device has at least a light-emitting layer between an anode and a cathode. The light-emitting layer comprises a luminescent material, a first organic compound, and a second organic compound. The luminescent material is a material exhibiting fluorescent emission. The first organic compound has any one of an anthracene skeleton, a tetracene skeleton, a phenanthrene skeleton, a pyrene skeleton, a chrysene skeleton, a carbazole skeleton, and other specific skeletons. The second organic compound has any one of a fluorenylamine skeleton, a spirobifluorenylamine skeleton, a dibenzofuranylamine skeleton, a carbazolamine skeleton, a benzocarbazolamine skeleton, a dibenzocarbazolamine skeleton, a dibenzofuranamine skeleton, a benzonaphthofuranamine skeleton, a bisnaphthofuranamine skeleton, a dibenzothiopheneamine skeleton, a benzonaphthothiopheneamine skeleton, a bisnaphthothiopheneamine skeleton, and an arylamine skeleton.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] In recent years, research and development of light-emitting devices (also called light-emitting elements) that utilize electroluminescence (EL) has been actively conducted. The basic structure of these light-emitting devices is a layer containing a light-emitting substance sandwiched between a pair of electrodes. By applying a voltage to this device, light can be emitted from the light-emitting substance.

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

[0004] Furthermore, these light-emitting devices can be formed into a film, which allows for surface light emission. This makes it easy to form large-area devices that utilize surface light emission. This is a feature that is difficult to obtain with point light sources such as incandescent bulbs and LEDs, or linear light sources such as fluorescent lamps, making them highly useful as surface light sources for lighting and other applications.

[0005] Light-emitting devices that utilize electroluminescence can be broadly classified according to whether the light-emitting material is an organic compound or an inorganic compound. In the case of an organic EL device that uses an organic compound as the light-emitting material and has a layer containing the organic compound between a pair of electrodes, when a voltage is applied to the light-emitting device, electrons are injected from the cathode and holes are injected from the anode into the layer containing the organic compound, causing a current to flow. The injected electrons and holes then excite the organic compound, and light is emitted from the excited organic compound.

[0006] The types of excited states that organic compounds can form include singlet excited states (S * ) and triplet excited states (T * ), and light emission from the singlet excited state is called fluorescence, and light emission from the triplet excited state is called phosphorescence.

[0007] With regard to such light-emitting devices, there are many problems that depend on the material in improving the device characteristics, and in order to overcome these problems, improvements in device structure, material development, etc. For example, Patent Document 1 discloses a carbazole derivative with high hole transport properties as an organic compound that can be used to form a light-emitting device with high luminous efficiency. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-298767 Summary of the Invention [Problem to be solved by the invention]

[0009] As described above, in order to improve the characteristics of light-emitting devices, it is desirable to develop organic compounds having properties suitable for light-emitting devices. One embodiment of the present invention aims to provide a fluorescent light-emitting device with high emission efficiency using an organic compound that has a low HOMO (highest occupied molecular orbital) level and hole-transporting properties. Another object of the present invention is to provide a light-emitting device, light-emitting apparatus, electronic device, or lighting apparatus with low power consumption.

[0010] Note that the description of these problems does not preclude the existence of other problems. Note that one embodiment of the present invention does not necessarily solve all of these problems. Note that problems other than these will become apparent from the description of the specification, drawings, claims, etc., and it is possible to extract other problems from the description of the specification, drawings, claims, etc. [Means for solving the problem]

[0011] One embodiment of the present invention provides an organic EL device including at least a light-emitting layer between an anode and a cathode. The light-emitting layer includes a light-emitting substance, a first organic compound, and a second organic compound. The light-emitting substance is a substance that exhibits fluorescent emission. The first organic compound has at least one of an anthracene skeleton, a tetracene skeleton, a phenanthrene skeleton, a pyrene skeleton, a chrysene skeleton, a carbazole skeleton, a benzocarbazole skeleton, a dibenzocarbazole skeleton, a dibenzofuran skeleton, a benzonaphthofuran skeleton, a bisnaphthofuran skeleton, a dibenzothiophene skeleton, a benzonaphthothiophene skeleton, a bisnaphthothiophene skeleton, and a fluoranthene skeleton. The second organic compound has at least one of a fluorenylamine skeleton, a spirobifluorenylamine skeleton, a dibenzofuranylamine skeleton, a fluoranthene skeleton, a fluorenylamine ... a light-emitting device having any one of a fluorenyl group, a spirobifluorenyl group, a dibenzofuranyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazole amine skeleton, a dibenzocarbazole amine skeleton, a dibenzofuran amine skeleton, a benzonaphthofuran amine skeleton, a bisnaphthofuran amine skeleton, a dibenzothiophene amine skeleton, a benzonaphthothiophene amine skeleton, a bisnaphthothiophene amine skeleton, and an arylamine skeleton, wherein the arylamine skeleton has any one of a fluorenyl group, a spirobifluorenyl group, a dibenzofuranyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a benzonaphthofuranyl group, a bisnaphthofuranyl group, a dibenzothiophenyl group, a benzonaphthothiophenyl group, and a bisnaphthothiophenyl group.

[0012] Another embodiment of the present invention is a light-emitting device including at least a light-emitting layer between an anode and a cathode. The light-emitting layer includes a light-emitting substance, a first organic compound, and a second organic compound. The light-emitting substance is a substance that exhibits fluorescent emission. The first organic compound has any one of an anthracene skeleton, a tetracene skeleton, a phenanthrene skeleton, a pyrene skeleton, a chrysene skeleton, a carbazole skeleton, a benzocarbazole skeleton, a dibenzocarbazole skeleton, a dibenzofuran skeleton, a benzonaphthofuran skeleton, a bisnaphthofuran skeleton, a dibenzothiophene skeleton, a benzonaphthothiophene skeleton, a bisnaphthothiophene skeleton, and a fluoranthene skeleton. The second organic compound is represented by General Formula (G1).

[0013] [ka]

[0014] In the above general formula (G1), Ar 1 represents a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and Ar 2 and Ar 3 each independently represent any one of a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted spirobifluorenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted benzocarbazolyl group, a substituted or unsubstituted dibenzocarbazolyl group, a substituted or unsubstituted benzonaphthofuranyl group, a substituted or unsubstituted bisnaphthofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted benzonaphthothiophenyl group, and a substituted or unsubstituted bisnaphthothiophenyl group; A 1 or A 3 represents a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, and n, m, and k represent integers of 0 to 2. 1 ~Ar 3 and A 1 or A 3 When one or more of the above groups have one or more substituents, the substituents are each independently an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms. Note that the aryl group does not include a heteroaryl group. In addition, the substituents may be bonded to each other to form a ring, and some or all of the hydrogen atoms may be deuterium.

[0015] Another embodiment of the present invention is a light-emitting device including at least a light-emitting layer between an anode and a cathode. The light-emitting layer includes a light-emitting substance, a first organic compound, and a second organic compound. The light-emitting substance is a substance that exhibits fluorescent emission. The first organic compound has any one of an anthracene skeleton, a tetracene skeleton, a phenanthrene skeleton, a pyrene skeleton, a chrysene skeleton, a carbazole skeleton, a benzocarbazole skeleton, a dibenzocarbazole skeleton, a dibenzofuran skeleton, a benzonaphthofuran skeleton, a bisnaphthofuran skeleton, a dibenzothiophene skeleton, a benzonaphthothiophene skeleton, a bisnaphthothiophene skeleton, and a fluoranthene skeleton. The second organic compound is represented by General Formula (G2).

[0016] [ka]

[0017] In the above general formula (G2), Ar 1 represents a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and Ar 2 and Ar 3 each independently represents any one of a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted spirobifluorenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted benzocarbazolyl group, a substituted or unsubstituted dibenzocarbazolyl group, a substituted or unsubstituted benzonaphthofuranyl group, a substituted or unsubstituted bisnaphthofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted benzonaphthothiophenyl group, and a substituted or unsubstituted bisnaphthothiophenyl group. 1 ~Ar 3 When one or more of the above groups have one or more substituents, the substituents are each independently an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms. Note that the aryl group does not include a heteroaryl group. In addition, the substituents may be bonded to each other to form a ring, and some or all of the hydrogen atoms may be deuterium.

[0018] Another embodiment of the present invention is a light-emitting device including at least a light-emitting layer between an anode and a cathode. The light-emitting layer includes a light-emitting substance, a first organic compound, and a second organic compound. The light-emitting substance is a substance that exhibits fluorescent emission. The first organic compound has any one of an anthracene skeleton, a tetracene skeleton, a phenanthrene skeleton, a pyrene skeleton, a chrysene skeleton, a carbazole skeleton, a benzocarbazole skeleton, a dibenzocarbazole skeleton, a dibenzofuran skeleton, a benzonaphthofuran skeleton, a bisnaphthofuran skeleton, a dibenzothiophene skeleton, a benzonaphthothiophene skeleton, a bisnaphthothiophene skeleton, and a fluoranthene skeleton. The second organic compound is represented by General Formula (G3).

[0019] [ka]

[0020] In the general formula (G3) above, Ar 1 represents a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and Ar 3 represents any one of a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted spirobifluorenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted benzocarbazolyl group, a substituted or unsubstituted dibenzocarbazolyl group, a substituted or unsubstituted benzonaphthofuranyl group, a substituted or unsubstituted bisnaphthofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted benzonaphthothiophenyl group, and a substituted or unsubstituted bisnaphthothiophenyl group; R 1 ~R 9 each independently represents hydrogen (including deuterium), an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms. 1 and Ar 3When one or both of the groups have one or more substituents, the substituents are each independently an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms. Note that the aryl group does not include a heteroaryl group. In addition, the substituents may be bonded to each other to form a ring.

[0021] Another embodiment of the present invention is a light-emitting device including at least a light-emitting layer between an anode and a cathode. The light-emitting layer includes a light-emitting substance, a first organic compound, and a second organic compound. The light-emitting substance is a substance that exhibits fluorescent emission. The first organic compound has any one of an anthracene skeleton, a tetracene skeleton, a phenanthrene skeleton, a pyrene skeleton, a chrysene skeleton, a carbazole skeleton, a benzocarbazole skeleton, a dibenzocarbazole skeleton, a dibenzofuran skeleton, a benzonaphthofuran skeleton, a bisnaphthofuran skeleton, a dibenzothiophene skeleton, a benzonaphthothiophene skeleton, a bisnaphthothiophene skeleton, and a fluoranthene skeleton. The second organic compound is represented by General Formula (G4).

[0022] [ka]

[0023] In the general formula (G4), X represents oxygen or sulfur, and R 21 and R 22 and R 31 ~R 37 each independently represents hydrogen (including deuterium), an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms; R 38 ~R 46 each independently represents hydrogen (including deuterium), an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms; R 47 ~R 53 Each of R independently represents hydrogen (including deuterium), an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms. Note that the aryl group does not include a heteroaryl group. 21 and R 22 and R 31 ~R 37At least two of the groups represented by R may be bonded to each other to form a ring. 38 ~R 46 At least two of the groups represented by R may be bonded to each other to form a ring. 47 ~R 53 At least two of the groups represented by the formula (I) may be bonded to each other to form a ring.

[0024] Another embodiment of the present invention is a light-emitting device having any of the above structures, in which the difference between the lowest singlet excitation level and the lowest triplet excitation level of the light-emitting substance is 0.3 eV or more.

[0025] Another embodiment of the present invention is a light-emitting device in which the light-emitting substance in each of the above structures is a substance that emits blue light.

[0026] Another embodiment of the present invention is a light-emitting device including any one of the light-emitting devices having the above structures and a transistor or a substrate.

[0027] Another embodiment of the present invention is an electronic device including a light-emitting device having any of the above structures and a detection unit, an input unit, or a communication unit.

[0028] Another embodiment of the present invention is a lighting device including a light-emitting device having any of the above structures and a housing. [Effects of the Invention]

[0029] According to one embodiment of the present invention, a light-emitting device that emits fluorescent light with high efficiency and uses an organic compound that has a low HOMO level and a hole-transporting property can be provided.Furthermore, a light-emitting device, a light-emitting apparatus, an electronic device, or a lighting apparatus that consumes low power can be provided.

[0030] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. Note that effects other than these will become apparent from the description in the specification, drawings, claims, etc., and it is possible to extract other effects from the description in the specification, drawings, claims, etc. [Brief explanation of the drawings]

[0031] [Figure 1] 1A to 1C are diagrams illustrating the configuration of a light-emitting device according to an embodiment. [Figure 2] 2A to 2E are diagrams illustrating the configuration of a light-emitting device according to an embodiment. [Figure 3] 3A to 3D are diagrams illustrating a light emitting device according to an embodiment. [Figure 4] 4A to 4C are diagrams illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 5] 5(A) to 5(C) are diagrams illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 6] 6(A) to 6(C) are diagrams illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 7] 7(A) to 7(D) are diagrams illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 8] 8(A) to 8(E) are diagrams illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 9] 9A to 9F are diagrams illustrating a device and pixel arrangement according to an embodiment. [Figure 10] 10A to 10C are diagrams illustrating a pixel circuit according to an embodiment. [Figure 11] FIG. 11 is a diagram illustrating a light emitting device according to an embodiment. [Figure 12] 12A to 12E illustrate electronic devices according to embodiments of the present invention. [Figure 13] 13A to 13E are diagrams illustrating electronic devices according to embodiments. [Figure 14] 14A and 14B are diagrams illustrating an electronic device according to an embodiment. [Figure 15] 15(A) and 15(B) are diagrams illustrating an illumination device according to an embodiment. [Figure 16] FIG. 16 is a diagram illustrating a lighting device according to an embodiment. [Figure 17] 17A to 17C are diagrams illustrating a light emitting device and a light receiving device according to an embodiment. [Figure 18] 18(A) and 18(B) are diagrams illustrating a light emitting device and a light receiving device according to the embodiment. [Figure 19] FIG. 19 is a diagram illustrating the configuration of a light-emitting device according to an example. [Figure 20] FIG. 20 shows the luminance-current density characteristics of the light-emitting device 1, the light-emitting device 2, and the comparative light-emitting device 3. [Figure 21] FIG. 21 shows the current efficiency-luminance characteristics of the light-emitting device 1, the light-emitting device 2, and the comparative light-emitting device 3. [Figure 22] FIG. 22 shows the luminance-voltage characteristics of the light-emitting device 1, the light-emitting device 2, and the comparative light-emitting device 3. [Figure 23] FIG. 23 shows the current-voltage characteristics of the light-emitting device 1, the light-emitting device 2, and the comparative light-emitting device 3. [Figure 24] FIG. 24 shows the blue index-luminance characteristics of the light-emitting device 1, the light-emitting device 2, and the comparative light-emitting device 3. [Figure 25] FIG. 25 shows the external quantum efficiency-luminance characteristics of the light-emitting device 1, the light-emitting device 2, and the comparative light-emitting device 3. [Figure 26] FIG. 26 shows the emission spectra of the light-emitting device 1, the light-emitting device 2, and the comparative light-emitting device 3. [Figure 27]FIG. 27 shows the luminance-current density characteristics of the light-emitting device 4 and the comparative light-emitting device 5. [Figure 28] FIG. 28 shows the current efficiency-luminance characteristics of the light-emitting device 4 and the comparative light-emitting device 5. [Figure 29] FIG. 29 shows the luminance-voltage characteristics of the light-emitting device 4 and the comparative light-emitting device 5. [Figure 30] FIG. 30 shows the current-voltage characteristics of the light-emitting device 4 and the comparative light-emitting device 5. [Figure 31] FIG. 31 shows the blue index-luminance characteristics of Light-Emitting Device 4 and Comparative Light-Emitting Device 5. [Figure 32] FIG. 32 shows the external quantum efficiency-luminance characteristics of the light-emitting device 4 and the comparative light-emitting device 5. [Figure 33] FIG. 33 shows the emission spectra of Light-Emitting Device 4 and Comparative Light-Emitting Device 5. DETAILED DESCRIPTION OF THE INVENTION

[0032] (Embodiment 1) In this embodiment, a light-emitting device according to one embodiment of the present invention will be described.

[0033] 1A shows a structure of a light-emitting device 100 according to one embodiment of the present invention. As shown in FIG. 1A, the light-emitting device 100 includes a first electrode 101 and a second electrode 102, and an EL layer 103 in which a hole-injection layer 111, a hole-transport layer 112, a light-emitting layer 113, an electron-transport layer 114, and an electron-injection layer 115 are sequentially stacked between the first electrode 101 and the second electrode 102.

[0034] The light-emitting layer 113 includes a light-emitting substance, a first organic compound, and a second organic compound.

[0035] A substance that exhibits fluorescent emission (fluorescent substance) can be used as the light-emitting substance contained in the light-emitting layer 113. In other words, a light-emitting substance that converts singlet excitation energy into light emission can be used as the light-emitting substance. In other words, a light-emitting substance that can convert singlet excitation energy into light emission and that can convert the difference between the lowest singlet excitation level and the lowest triplet excitation level (ΔE ST ) of 0.3 eV or more can be used, which allows the EL layer 103 to emit fluorescent light.

[0036] Furthermore, for example, a substance that emits blue light can be used as the light-emitting substance, which allows the EL layer 103 to emit blue light. Note that in this specification and the like, a substance that emits blue light refers to a light-emitting substance whose emission spectrum has a maximum peak in the wavelength range of 400 nm to 490 nm.

[0037] The light-emitting substance is not limited to a substance that emits blue light. For example, the EL layer 103 may be configured to emit red light by using a substance that emits red light. Alternatively, the EL layer 103 may be configured to emit green light by using a substance that emits green light.

[0038] Specific examples of fluorescent materials will be described in the second embodiment.

[0039] As the first organic compound, it is preferable to use an organic compound having a high energy level in the singlet excited state and a low energy level in the triplet excited state. It is also preferable to use an organic compound having a high fluorescence quantum yield. It is also preferable to use an organic compound having a high energy level in the singlet excited state, a low energy level in the triplet excited state, and a high fluorescence quantum yield.

[0040] The first organic compound contained in the light-emitting layer 113 can be an organic compound having one or more of fused ring skeletons with high carrier transport properties, such as an anthracene skeleton, a tetracene skeleton, a phenanthrene skeleton, a pyrene skeleton, a chrysene skeleton, a carbazole skeleton, a benzocarbazole skeleton, a dibenzocarbazole skeleton, a dibenzofuran skeleton, a benzonaphthofuran skeleton, a bisnaphthofuran skeleton, a dibenzothiophene skeleton, a benzonaphthothiophene skeleton, a bisnaphthothiophene skeleton, and a fluoranthene skeleton.

[0041] Furthermore, it is preferable that the first organic compound does not have an amine skeleton. It is also preferable that the first organic compound is composed of either or both of an aromatic hydrocarbon ring and a heteroaromatic ring. It is more preferable that the first organic compound is composed of an aromatic hydrocarbon ring.

[0042] As described above, by using the first organic compound having a fused ring skeleton with high carrier transport properties in the light-emitting layer 113, the driving voltage of the light-emitting device 100 can be reduced, and as a result, a light-emitting device 100 with low power consumption can be provided.

[0043] The energy level of the singlet excited state of a first organic compound having a fused ring skeleton with high carrier transport properties is high enough to obtain blue light emission, but the energy level of the triplet excited state may be low. When such an organic compound is used in the fluorescent-emitting layer, it becomes possible to generate singlet excitons from triplet excitons in the emitting layer by triplet-triplet annihilation (TTA). Therefore, by using the first organic compound, a light-emitting device 100 with high luminous efficiency can be provided.

[0044] Furthermore, since the exciton lifetime of fluorescence is approximately 1 / 100 of that of phosphorescence, the speed from generation of an excited state to emission is faster than that of phosphorescence, making it possible to provide a light-emitting device that is less susceptible to quenching. Furthermore, since fluorescent excitons have a short lifetime and are less susceptible to quenching, it is possible to provide a light-emitting device 100 that exhibits little deterioration in luminance over operating time.

[0045] A specific example of the first organic compound will be described in Embodiment 2.

[0046] The second organic compound contained in the light-emitting layer 113 can be any one or more of a fluorenylamine skeleton, a spirobifluorenylamine skeleton, a dibenzofuranylamine skeleton, a carbazoleamine skeleton, a benzocarbazoleamine skeleton, a dibenzocarbazoleamine skeleton, a dibenzofuranamine skeleton, a benzonaphthofuranamine skeleton, a bisnaphthofuranamine skeleton, a dibenzothiopheneamine skeleton, a benzonaphthothiopheneamine skeleton, a bisnaphthothiopheneamine skeleton, and an arylamine skeleton, wherein the arylamine skeleton has one or more of a fluorenyl group, a spirobifluorenyl group, a dibenzofuranyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzofuranyl group, a benzonaphthofuranyl group, a bisnaphthofuranyl group, a dibenzothiophenyl group, a benzonaphthothiophenyl group, and a bisnaphthothiophenyl group.

[0047] The second organic compound having such a structure is easy to accept holes (has hole transport properties), and therefore, when used in combination with the first organic compound having electron transport properties, it becomes easy to adjust the carrier balance in the light-emitting layer, thereby improving the luminous efficiency of the light-emitting device 100. In addition, since it is expected to have the effect of improving hole injection properties into the light-emitting layer 113, the driving voltage of the light-emitting device 100 can be reduced, and as a result, a light-emitting device with low power consumption can be provided.

[0048] The hole transport property of the second organic compound can be improved by making the second organic compound have a structure having one or more of a fluorenyl group, a spirobifluorenyl group, a dibenzofuranyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a benzonaphthofuranyl group, a bisnaphthofuranyl group, a dibenzothiophenyl group, a benzonaphthothiophenyl group, and a bisnaphthothiophenyl group.

[0049] Furthermore, the second organic compound may be more susceptible to oxygen addition than the first organic compound. In this case, even if oxygen or water is present in the light-emitting layer 113, oxygen is added to the second organic compound before the first organic compound, thereby preventing oxygen addition to the first organic compound. Therefore, by combining the first organic compound and the second organic compound, oxygen addition to the first organic compound can be prevented, and deterioration such as a decrease in efficiency or a change in the emission color of the light-emitting device 100 can be prevented.

[0050] The first organic compound and the second organic compound are organic compounds that function as host materials. When a plurality of host materials are used in the light-emitting layer, an exciplex may be formed. However, in the configuration of the light-emitting layer 113 of the light-emitting device 100, there are concerns that the emission wavelength may be longer, resulting in a decrease in color purity and a decrease in luminous efficiency. Therefore, it is preferable to use a combination that is less likely to form an exciplex, and it is more preferable to use a combination that does not form an exciplex.

[0051] A specific example of the second organic compound is an organic compound represented by the following general formula (G1).

[0052] [ka]

[0053] In the above general formula (G1), Ar 1 represents a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and Ar 2 and Ar 3each independently represent one or more of a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted spirobifluorenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted benzocarbazolyl group, a substituted or unsubstituted dibenzocarbazolyl group, a substituted or unsubstituted benzonaphthofuranyl group, a substituted or unsubstituted bisnaphthofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted benzonaphthothiophenyl group, and a substituted or unsubstituted bisnaphthothiophenyl group; A 1 or A 3 represents a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, and n, m, and k represent integers of 0 to 2. 1 ~Ar 3 and A 1 or A 3 When one or more of the above groups have one or more substituents, the substituents are each independently an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms. Note that the aryl group does not include a heteroaryl group. In addition, the substituents may be bonded to each other to form a ring, and some or all of the hydrogen atoms may be deuterium.

[0054] When n, m, and k are 0, the HOMO of the organic compound represented by (G1) can be deepened, and when n, m, and k are 1 or 2, the HOMO tends to be shallower than when n, m, and k are 0. In this way, the HOMO level can be changed by changing n, m, and k. When n, m, and k are 1 or 2, the molecular weight is larger than when n, m, and k are 0, which is preferable because the heat resistance is higher. On the other hand, when n, m, and k are 0, the sublimation property can be improved, which is preferable.

[0055] In general formula (G1), A 1 or A 3Specific examples of the arylene group having 6 to 30 carbon atoms that can be used in the above formula (A-1) include the substituents shown in structural formulas (A-3) to (A-14). 1 or A 3 The arylene group having 6 to 30 carbon atoms that can be used in A is not limited to the substituents shown in structural formulas (A-3) to (A-14). 1 or A 3 A heteroarylene group may be used. 1 or A 3 Specific examples of the heteroarylene group that can be used include the substituents shown in structural formulas (A-1) and (A-2).

[0056] [ka]

[0057] Specific examples of the second organic compound include organic compounds represented by the following general formula (G2).

[0058] [ka]

[0059] In the above general formula (G2), Ar 1 represents a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and Ar 2 and Ar 3 each independently represents one or more of a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted spirobifluorenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted benzocarbazolyl group, a substituted or unsubstituted dibenzocarbazolyl group, a substituted or unsubstituted benzonaphthofuranyl group, a substituted or unsubstituted bisnaphthofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted benzonaphthothiophenyl group, and a substituted or unsubstituted bisnaphthothiophenyl group. 1 ~Ar 3When one or more of the above groups have one or more substituents, the substituents are each independently an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms. Note that the aryl group does not include a heteroaryl group. In addition, the substituents may be bonded to each other to form a ring, and some or all of the hydrogen atoms may be deuterium.

[0060] In addition, nitrogen is directly 1 ~Ar 3 The organic compound represented by the general formula (G2) to which is bonded can be expected to have a high hole transport property. Therefore, by using the organic compound represented by the general formula (G2) in the light-emitting layer 113, it is possible to provide a light-emitting device 100 with low power consumption.

[0061] Specific examples of the second organic compound include organic compounds represented by the following general formula (G3).

[0062] [ka]

[0063] In the general formula (G3) above, Ar 1 represents a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and Ar 3 represents one or more of a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted spirobifluorenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted benzocarbazolyl group, a substituted or unsubstituted dibenzocarbazolyl group, a substituted or unsubstituted benzonaphthofuranyl group, a substituted or unsubstituted bisnaphthofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted benzonaphthothiophenyl group, and a substituted or unsubstituted bisnaphthothiophenyl group; R 1 ~R 9 each independently represents hydrogen (including deuterium), an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms. 1 and Ar 3When one or both of the groups have one or more substituents, the substituents are each independently an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms. Note that the aryl group does not include a heteroaryl group. In addition, the substituents may be bonded to each other to form a ring.

[0064] The organic compound represented by general formula (G3) has a molecular structure of fluorene-2-amine, and is therefore expected to have high hole transport properties and resistance to repeated oxidation. Therefore, by using the organic compound represented by general formula (G3) in the light-emitting layer 113, it is possible to provide a light-emitting device 100 that consumes low power and is highly reliable.

[0065] In addition, R in the above general formula (G3) 1 ~R 9 Specific examples of the alkyl group having 1 to 4 carbon atoms in the formula (I) include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, an isobutyl group, and a tert-butyl group, and specific examples of the aryl group having 6 to 13 carbon atoms include a phenyl group, a tolyl group, a xylyl group, a mesityl group, a biphenyl group, a naphthyl group, and a fluorenyl group. As described above, the substituents may be bonded to each other to form a ring, and for example, a spirobifluorenyl group is considered to be a group in which the substituents are bonded to form a ring (i.e., in a 9,9-diphenylfluorenyl group, two phenyl groups are bonded to form a ring to form a spirobifluorenyl group).

[0066] In the above general formulae (G1) to (G3), Ar 1 Examples of the aryl group having 6 to 30 carbon atoms that can be used in the formula (Ar-1) include the substituents shown in the formula (Ar-1) to the formula (Ar-17). 1 The aryl group having 6 to 30 carbon atoms that can be used is not limited to the substituents shown in structural formulas (Ar-1) to (Ar-17).

[0067] [ka]

[0068] In addition, Ar in the above general formula (G1) 1 ~Ar 3 and A 1 or A 3 has a substituent, Ar 1 ~Ar 3 has a substituent, or Ar 1 and Ar 3 When has a substituent, specific examples of the alkyl group having 1 to 4 carbon atoms that is the substituent of include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, an isobutyl group, and a tert-butyl group, and specific examples of the aryl group having 6 to 13 carbon atoms include a phenyl group, a tolyl group, a xylyl group, a mesityl group, a biphenyl group, a naphthyl group, and a fluorenyl group. Furthermore, as described above, the substituents may be bonded to each other to form a ring, and for example, a spirobifluorenyl group is considered to be a group in which the substituents are bonded to form a ring (i.e., in a 9,9-diphenylfluorenyl group, two phenyl groups are bonded to form a ring to form a spirobifluorenyl group).

[0069] In addition, Ar 1 It is more preferable to use the substituent represented by the above structural formula (Ar-4) as Ar. 1 It is expected that the planarity of the lone electron pair between the second organic compound and nitrogen will decrease, making it difficult for the conjugation to spread, and increasing the electron density on the nitrogen. Therefore, the hole transport property of the second organic compound can be improved, thereby reducing the driving voltage of the light-emitting device 100. Furthermore, since the increase in the vapor deposition temperature of the second organic compound is suppressed, a stable film can be formed by the vapor deposition method. It is also expected that the heat resistance of the light-emitting device 100 will be improved. Furthermore, it is expected that the reliability of the light-emitting device 100 will be improved.

[0070] In the above general formulas (G1) to (G3), it is more preferable that either one of a substituted or unsubstituted dibenzofuranyl group and a substituted or unsubstituted dibenzothiophenyl group is directly bonded to nitrogen. A specific example of the second organic compound is an organic compound represented by the following general formula (G4).

[0071] [ka]

[0072] In the general formula (G4), X represents oxygen or sulfur, and R 21 and R 22 and R 31 ~R 37 each independently represents hydrogen (including deuterium), an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms; R 38 ~R 46 each independently represents hydrogen (including deuterium), an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms; R 47 ~R 53 Each of R independently represents hydrogen (including deuterium), an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms. Note that the aryl group does not include a heteroaryl group. 21 and R 22 and R 31 ~R 37 At least two of the groups represented by R may be bonded to each other to form a ring. 38 ~R 46 At least two of the groups represented by R may be bonded to each other to form a ring. 47 ~R 53 At least two of the groups represented by the formula (I) may be bonded to each other to form a ring.

[0073] The organic compound represented by general formula (G4), like the organic compound represented by general formula (G3), has a molecular structure of fluorene-2-amine, and is therefore expected to have high hole transport properties and resistance to repeated oxidation. Therefore, by using the organic compound represented by general formula (G4) in the light-emitting layer 113, it is possible to provide a light-emitting device 100 that consumes low power and is highly reliable.

[0074] In the general formula (G4), R 21 and R 22 , R 31 ~R 37 , R 38 ~R 46 , R 47 ~R 53 Specific examples of the alkyl group having 1 to 4 carbon atoms in the formula (I) include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, an isobutyl group, and a tert-butyl group, and specific examples of the aryl group having 6 to 13 carbon atoms include a phenyl group, a tolyl group, a xylyl group, a mesityl group, a biphenyl group, a naphthyl group, and a fluorenyl group. 21 and R 22 and R 31 ~R 37 At least two of the groups represented by the formula (I) may be bonded to each other to form a ring, and for example, a spirobifluorenyl group is considered to be a ring formed by bonding these groups together (i.e., in a 9,9-diphenylfluorenyl group, two phenyl groups are bonded to form a ring to form a spirobifluorenyl group). 38 ~R 46 The substituents represented by R may be bonded to each other to form a ring. 47 ~R 53 At least two of the groups represented by R may be bonded to each other to form a ring. For example, a 9,9-dimethylfluorenyl group, a 9,9-diphenylfluorenyl group, and a spirobifluorenyl group are represented by R 38 and R 43 ~R 46 is considered to be bonded to any one of the groups to form a fluorene ring.

[0075] Specific examples of the second organic compound include organic compounds represented by the following general formula (G5).

[0076] [ka]

[0077] In the general formula (G5), X represents oxygen or sulfur, and R 21 and R 22 and R 31 ~R 37 each independently represents hydrogen (including deuterium), an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms; R 38 ~R 46 each independently represents hydrogen (including deuterium), an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms; R 47 ~R 53 Each of R independently represents hydrogen (including deuterium), an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms. Note that the aryl group does not include a heteroaryl group. 21 and R 22 and R 31 ~R 37 At least two of the groups represented by R may be bonded to each other to form a ring. 38 ~R 46 At least two of the groups represented by R may be bonded to each other to form a ring. 47 ~R 53 At least two of the groups represented by the formula (I) may be bonded to each other to form a ring.

[0078] General formula (G5) differs from general formula (G4) in that the bonding position of the biphenyl group to the nitrogen is limited to the ortho position. This is expected to reduce the planarity of the lone electron pair between the biphenyl group and the nitrogen, making it difficult for the conjugation to extend and increasing the electron density on the nitrogen. Therefore, the hole transport property of the second organic compound can be improved, thereby reducing the driving voltage of the light-emitting device 100. Furthermore, since the increase in the vapor deposition temperature of the second organic compound is suppressed, a stable film can be formed by the vapor deposition method. Furthermore, the heat resistance of the light-emitting device 100 can be improved. Furthermore, the reliability of the light-emitting device 100 can be improved.

[0079] Next, specific examples of organic compounds according to one embodiment of the present invention, each having the structure represented by any of the above general formulae (G1) to (G5), will be shown below.

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[0119] The organic compounds represented by the structural formulae (100) to (161), (200) to (319), (400) to (519), (600) to (620), (800) to (849), and (900) to (947) are examples of the organic compounds represented by the general formulae (G1) to (G5); however, organic compounds that can be used in the light-emitting device of one embodiment of the present invention are not limited to these.

[0120] Next, a synthesis method for an organic compound represented by General Formula (G1), which is an example of the second organic compound, will be described. Note that various reactions can be applied as a synthesis method for an organic compound of one embodiment of the present invention. Therefore, the synthesis method for an organic compound of one embodiment of the present invention is not limited to the synthesis method described below.

[0121] [ka]

[0122] In the above general formula (G1), Ar 1 represents a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and Ar 2 and Ar 3 each independently represent a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted spirobifluorenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted benzocarbazolyl group, a substituted or unsubstituted dibenzocarbazolyl group, a substituted or unsubstituted benzonaphthofuranyl group, a substituted or unsubstituted bisnaphthofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted benzonaphthothiophenyl group, or a substituted or unsubstituted bisnaphthothiophenyl group; A 1 or A 3represents a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, and n, m, and k represent integers of 0 to 2. 1 ~Ar 3 and A 1 or A 3 When one or more of the above groups have one or more substituents, the substituents are each independently an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms. Note that the aryl group does not include a heteroaryl group. In addition, the substituents may be bonded to each other to form a ring, and some or all of the hydrogen atoms may be deuterium.

[0123] The synthetic schemes (a-1-1) or (a-1-2) and (a-2), the synthetic schemes (a-3-1) or (a-3-2) and (a-4), and the synthetic schemes (a-5-1) or (a-5-2) and (a-6) of the organic compound represented by general formula (G1) are shown below.

[0124] [ka]

[0125] [ka]

[0126] [ka]

[0127] In addition, in the synthetic schemes (a-1-1) or (a-1-2) and (a-2), the synthetic schemes (a-3-1) or (a-3-2) and (a-4), and the synthetic schemes (a-5-1) or (a-5-2) and (a-6), Ar 1 ~Ar 3 , A 1 or A 3 The explanation for n, m, and k is the same as that shown above, so it will be omitted. 1 ~X 3represents a halogen or trifluoromethanesulfonic acid group, preferably chlorine, bromine, or iodine.

[0128] As shown in the above synthetic schemes (a-1-1) or (a-1-2) and (a-2), synthetic schemes (a-3-1) or (a-3-2) and (a-4), and synthetic schemes (a-5-1) or (a-5-2) and (a-6), a secondary amine compound is obtained by coupling a compound having an amino group with a compound such as a halide. The resulting secondary amine compound can then be coupled with a compound such as a halide to obtain the desired organic compound represented by (G1). As shown in synthetic schemes (a-1-1) or (a-1-2) and (a-2), synthetic schemes (a-3-1) or (a-3-2) and (a-4), and synthetic schemes (a-5-1) or (a-5-2) and (a-6), the desired organic compound represented by (G1) can be obtained regardless of the order in which the coupling reactions are performed. Therefore, any materials can be selected and used for the synthesis.

[0129] Also, Ar 2 and Ar 3 and A are the same substituents, and 2 and A 3 and are the same substituents, that is, when compound 5 and compound 6 can have the same molecular structure, the organic compound represented by (G1) may be synthesized in two steps as shown in the synthetic schemes (a-1-1) or (a-1-2) and (a-2), or the organic compound represented by (G1) may be synthesized in one step by coupling two equivalents of compound 5 to compound 4.

[0130] In the synthesis schemes (a-1-1) or (a-1-2) and (a-2), (a-3-1) or (a-3-2) and (a-4), and (a-5-1) or (a-5-2) and (a-6), when the Buchwald-Hartwig reaction is carried out using a palladium catalyst, bis(dibenzylideneacetone)palladium(0), palladium(II) acetate, [1,1-bis(diphenylphosphino)ferrocene]palladium(II) dichloride, tetrakis(triphenylphosphine)palladium(0), allylpalladium(II) Palladium compounds such as palladium chloride (dimer) and ligands such as tri(tert-butyl)phosphine, tri(n-hexyl)phosphine, tricyclohexylphosphine, di(1-adamantyl)-n-butylphosphine, 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl, tri(ortho-tolyl)phosphine, (S)-(6,6'-dimethoxybiphenyl-2,2'-diyl)bis(diisopropylphosphine) (abbreviated as cBRIDP), and 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene can be used. In addition, organic bases such as sodium tert-butoxide, or inorganic bases such as potassium carbonate, cesium carbonate, and sodium carbonate can be used in this reaction. In addition, solvents such as toluene, xylene, benzene, tetrahydrofuran, and dioxane can be used in this reaction. The reagents that can be used in this reaction are not limited to those listed above. Furthermore, a compound in which an organotin group is bonded to an amino group can also be used in place of a compound having an amino group.

[0131] In addition, in the synthetic schemes (a-1-1) or (a-1-2) and (a-2), (a-3-1) or (a-3-2) and (a-4), and (a-5-1) or (a-5-2) and (a-6), the Ullmann reaction can also be carried out using copper or a copper compound. Examples of the base used include inorganic bases such as potassium carbonate. Examples of solvents that can be used in this reaction include 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)pyrimidinone (DMPU), toluene, xylene, and benzene. In the Ullmann reaction, a reaction temperature of 100°C or higher allows the desired product to be obtained in a shorter time and with a higher yield, so it is preferable to use DMPU or xylene, which have high boiling points. Furthermore, a reaction temperature of 150°C or higher is even more preferable, so DMPU is more preferably used. The reagents that can be used in this reaction are not limited to those listed above.

[0132] As described above, the organic compound represented by general formula (G1) can be synthesized. An amine compound used in the coupling reaction, for example, compound 2 which is the reactant in the above synthesis scheme (a-1-1), can be synthesized by amminating compound 5 according to the following synthesis schemes (a-7) and (a-8).

[0133] [ka]

[0134] In the synthesis schemes (a-7) and (a-8), Ar 2 and A 2 is the same as general formula (G1), and X 1 is the same as in the synthetic scheme (a-1-1).

[0135] In the synthetic scheme (a-7), when a coupling reaction using a palladium catalyst is performed, palladium compounds such as bis(dibenzylideneacetone)palladium(0), palladium(II) acetate, [1,1-bis(diphenylphosphino)ferrocene]palladium(II) dichloride, tetrakis(triphenylphosphine)palladium(0), and allylpalladium(II) chloride (dimer) can be used, along with ligands such as tri(tert-butyl)phosphine, tri(n-hexyl)phosphine, tricyclohexylphosphine, di(1-adamantyl)-n-butylphosphine, 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl, tri(ortho-tolyl)phosphine, cBRIDP, and 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene. In addition, in this reaction, an organic base such as sodium tert-butoxide, or an inorganic base such as potassium carbonate, cesium carbonate, or sodium carbonate can be used. In addition, in this reaction, toluene, xylene, benzene, tetrahydrofuran, dioxane, or the like can be used as a solvent. The reagents that can be used in this reaction are not limited to the above-mentioned reagents. In addition, a compound in which an organotin group is bonded to an amino group can also be used instead of a compound having an amino group.

[0136] In addition, in the synthetic scheme (a-7), the Ullmann reaction can also be carried out using copper or a copper compound. Examples of the base used include inorganic bases such as potassium carbonate. Examples of solvents that can be used in this reaction include 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)pyrimidinone (DMPU), toluene, xylene, and benzene. In the Ullmann reaction, a reaction temperature of 100°C or higher allows the target product to be obtained in a shorter time and with a higher yield, so it is preferable to use DMPU or xylene, which have high boiling points. Furthermore, a reaction temperature of 150°C or higher is even more preferable, so DMPU is more preferably used. Reagents that can be used in this reaction are not limited to those listed above.

[0137] When an acid is used in carrying out the hydrolysis reaction shown in the synthetic scheme (a-8), an acid having no dehydrating action, such as trifluoroacetic acid, trifluoromethanesulfonic acid, acetic acid, hydrochloric acid, or hydrobromic acid, is preferably used. When a base is used, an aqueous sodium hydroxide solution or an aqueous potassium hydroxide solution can be used.

[0138] Compounds 4 and 8, which are amine compounds shown in synthetic schemes (a-1-2), (a-3-2), (a-5-1), and (a-5-2), can also be synthesized using reactions similar to those in the synthetic schemes (a-7) and (a-8), and can be synthesized by aminating compounds 6 and 1, respectively, as shown in the synthetic schemes (a-9) and (a-10) below. The amination reactions shown in synthetic schemes (a-9) and (a-10) can be synthesized by synthetic methods similar to those in the synthetic schemes (a-7) and (a-8).

[0139] [ka]

[0140] Although an example of a method for synthesizing the second organic compound has been described above, the present invention is not limited to this, and the second organic compound may be synthesized by any other synthesis method.

[0141] 1(B) and 1(C) show examples of the specific structure of the light-emitting device 100 shown in FIG. 1(A). FIG. 1(B) shows a structure in which a hole injection layer 111, a hole transport layer 112, a light-emitting layer 113, an electron transport layer 114, and an electron injection layer 115 are sequentially stacked on a first electrode 101. As can be seen from the cross-sectional view of FIG. 1(B), the structure has the ends (or side faces) of the hole injection layer 111, the hole transport layer 112, the light-emitting layer 113, and the electron transport layer 114 located inward relative to the end (or side face) of the first electrode 101. The structure also has the ends (or side faces) of the hole injection layer 111, the hole transport layer 112, the light-emitting layer 113, and the electron transport layer 114 in contact with a part of the top and end (or side face) of the first electrode 101 and the insulating layer 107.

[0142] By providing the insulating layer 107, the ends (or sides) of the hole injection layer 111, the hole transport layer 112, the ends (or sides) of the light-emitting layer 113, and the ends (or sides) of the electron transport layer 114 can be protected. Thereby, damage to each layer due to the process can be suppressed, and it becomes possible to prevent electrical connection due to contact with different layers.

[0143] The electron injection layer 115 is a part of the EL layer 103, but as shown in FIG. 1(B), it has a different shape from the other layers (hole injection layer 111, hole transport layer 112, light-emitting layer 113, electron transport layer 114) of the EL layer 103. However, the electron injection layer 115 and the second electrode 102 can have the same shape. Since the electron injection layer 115 and the second electrode 102 can be made into layers common to a plurality of light-emitting devices, the manufacturing process of the light-emitting device 100 can be simplified, and the throughput can be improved.

[0144] Also, a light-emitting device having a structure as shown in FIG. 1(C) may be used. The hole injection layer 111, the hole transport layer 112, the light-emitting layer 113, the electron transport layer 114, and the electron injection layer 115 are sequentially laminated on the first electrode 101 so as to cover the first electrode 101. In the cross-sectional view of FIG. 1(C), the ends of the hole injection layer 111, the hole transport layer 112, the light-emitting layer 113, and the electron transport layer 114 are located outside the ends (or sides) of the first electrode 101. Also, it has a structure in which the ends of the hole injection layer 111, the hole transport layer 112, the light-emitting layer 113, and the electron transport layer 114 are in contact with the insulating layer 107.

[0145] The insulating layer 107 is in contact with the end (or side) of the hole injection layer 111, the end (or side) of the hole transport layer 112, the end (or side) of the light-emitting layer 113, and the end (or side) of the electron transport layer 114. The insulating layer 107 is located between the end (or side) of the hole injection layer 111, the end (or side) of the hole transport layer 112, the end (or side) of the light-emitting layer 113, and the end (or side) of the electron transport layer 114 and the second insulating layer 140. An electron injection layer 115 is provided on the second insulating layer 140, the insulating layer 107, and the electron transport layer 114. The second insulating layer 140 can be made of an organic compound or an inorganic compound.

[0146] When an organic compound is used for the second insulating layer 140, for example, an acrylic resin, a polyimide resin, an epoxy resin, a polyamide resin, a polyimideamide resin, a siloxane resin, a benzocyclobutene-based resin, a phenolic resin, or a precursor of these resins can be used. Alternatively, a photosensitive resin can be used. As the photosensitive resin, a positive-type material or a negative-type material can be used.

[0147] By using a photosensitive resin as the second insulating layer 140, the second insulating layer 140 can be produced by only the steps of exposure and development in the manufacturing process, thereby reducing the influence on other layers due to dry etching, wet etching, etc. Furthermore, by using a negative photosensitive resin, it is possible to use a photomask (exposure mask) used in another process, which is preferable.

[0148] 1(B) and 1(C), when a portion of the EL layer 103 is patterned during the manufacturing process to form a desired shape, the processed surface may be subjected to heat and / or exposure to the atmosphere, which may cause problems such as crystallization of the light-emitting layer 113 or the electron transport layer 114, resulting in reduced reliability and brightness of the light-emitting device. In contrast, the light-emitting device 100 described in the first embodiment is patterned after the electron transport layer 114 is formed, thereby preventing problems such as crystallization of the light-emitting layer 113. In this case, the electron injection layer 115, which is a part of the EL layer 103, is formed after the electron transport layer 114 is formed. Therefore, only the electron injection layer 115 has a structure different from the other layers of the EL layer 103 (the hole injection layer 111, the hole transport layer 112, the light-emitting layer 113, and the electron transport layer 114).

[0149] 1B and 1C is an example of a device structure that can be patterned by such a manufacturing method, but the shape of the light-emitting device of one embodiment of the present invention is not limited to this. Note that by having such a device structure of one embodiment of the present invention, a light-emitting device in which a decrease in efficiency and a deterioration in reliability are suppressed can be provided.

[0150] 1B and 1C, the insulating layer 107 may be omitted if unnecessary. For example, if the conduction between the electron injection layer 115 and the hole injection layer 111 and between the electron injection layer 115 and the hole transport layer 112 is sufficiently small, the light-emitting device 100 may not have the insulating layer 107.

[0151] As materials that can be used for the first electrode 101, the second electrode 102, the hole injection layer 111, the hole transport layer 112, the light-emitting layer 113, the electron injection layer 115, and the insulating layer 107, materials to be described in a later embodiment can be applied.

[0152] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0153] (Embodiment 2) In this embodiment mode, other structures of the light-emitting device shown in Embodiment Mode 1 will be described with reference to FIGS.

[0154] <Basic structure of light-emitting devices> The basic structure of a light-emitting device will be described. Figure 2(A) shows a light-emitting device having an EL layer including a light-emitting layer between a pair of electrodes. Specifically, the device has a structure in which an EL layer 103 is sandwiched between a first electrode 101 and a second electrode 102.

[0155] 2(B) shows a light-emitting device with a stacked structure (tandem structure) having multiple EL layers (two layers in FIG. 2(B)) (103a, 103b) between a pair of electrodes, with a charge generation layer 106 between the EL layers. A light-emitting device with a tandem structure can realize a highly efficient light-emitting device without changing the amount of current.

[0156] The charge generation layer 106 has a function of injecting electrons into one EL layer (103a or 103b) and injecting holes into the other EL layer (103b or 103a) when a potential difference is generated between the first electrode 101 and the second electrode 102. Therefore, in FIG. 2(B), when a voltage is applied to the first electrode 101 so that the 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.

[0157] From the viewpoint of light extraction efficiency, the charge generation layer 106 is preferably transparent to visible light (specifically, the visible light transmittance of the charge generation layer 106 is 40% or more). The charge generation layer 106 functions even if it has lower conductivity than the first electrode 101 and the second electrode 102.

[0158] FIG. 2C shows a stacked structure of the EL layer 103 of the light-emitting device according to one embodiment of the present invention. In this case, the first electrode 101 functions as an anode, and the second electrode 102 functions as a cathode. The 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 stacked over the first electrode 101. The light-emitting layer 113 may have a stacked structure of a plurality of light-emitting layers emitting different colors. For example, a light-emitting layer containing a red light-emitting substance, a light-emitting layer containing a green light-emitting substance, and a light-emitting layer containing a blue light-emitting substance may be stacked, or a layer containing a carrier-transporting material may be interposed between the light-emitting layers. Alternatively, a light-emitting layer containing a yellow light-emitting substance and a light-emitting layer containing a blue light-emitting substance may be combined. However, the stacked structure of the light-emitting layer 113 is not limited to the above. For example, the light-emitting layer 113 may have a structure in which multiple light-emitting layers emitting the same light color are stacked. For example, a first light-emitting layer containing a blue light-emitting substance and a second light-emitting layer containing a blue light-emitting substance are stacked, or a layer containing a carrier-transporting material is interposed between the layers. A structure in which multiple light-emitting layers emitting the same light color are stacked may have higher reliability than a single-layer structure. Even in a tandem structure such as that shown in FIG. 2B, in which multiple EL layers are provided, each EL layer is stacked in order from the anode side as described above. Furthermore, when the first electrode 101 is a cathode and the second electrode 102 is an anode, the stacking order of the EL layer 103 is reversed. Specifically, the structure is such that 111 on the first electrode 101, which is a cathode, is an electron injection layer, 112 is an electron transport layer, 113 is a light-emitting layer, 114 is a hole transport layer, and 115 is a hole injection layer.

[0159] The light-emitting layers 113 included in the EL layers (103, 103a, 103b) each contain a light-emitting substance and an appropriate combination of multiple substances, and can be configured to emit fluorescent or phosphorescent light of a desired emission color. The light-emitting layer 113 may also have a stacked structure with different emission colors. In this case, different materials may be used for the light-emitting substance and other substances used in each stacked light-emitting layer. Alternatively, a structure in which different emission colors are emitted from the multiple EL layers (103a, 103b) shown in Figure 2(B) may also be used. In this case, different materials may be used for the light-emitting substance and other substances used in each light-emitting layer.

[0160] In addition, in a light-emitting device according to one embodiment of the present invention, for example, the first electrode 101 shown in FIG. 2(C) is a reflective electrode, the second electrode 102 is a semi-transmissive and semi-reflective electrode, and a micro-optical resonator (microcavity) structure is formed. This allows light emission from the light-emitting layer 113 included in the EL layer 103 to resonate between the two electrodes, thereby enhancing the light emission emitted from the second electrode 102.

[0161] When the first electrode 101 of the light-emitting device is a reflective electrode having a laminated structure of a reflective conductive material and a light-transmitting conductive material (transparent conductive film), optical adjustment can be performed by controlling the film thickness of the transparent conductive film. Specifically, it is preferable to adjust the optical distance (product of film thickness and refractive index) between the first electrode 101 and the second electrode 102 to mλ / 2 (where m is an integer of 1 or greater) or in the vicinity thereof, for the wavelength λ of light obtained from the light-emitting layer 113.

[0162] Furthermore, in order to amplify the desired light (wavelength: λ) obtained from the light-emitting layer 113, it is preferable to adjust the optical distance from the first electrode 101 to the region (light-emitting region) in the light-emitting layer 113 where the desired light is obtained and the optical distance from the second electrode 102 to the region (light-emitting region) in the light-emitting layer 113 where the desired light is obtained to be (2m'+1)λ / 4 (where m' is an integer of 1 or greater) or close to that. Note that the light-emitting region here refers to the recombination region of holes and electrons in the light-emitting layer 113.

[0163] By performing such optical adjustment, the spectrum of the specific monochromatic light obtained from the light-emitting layer 113 can be narrowed, and light with high color purity can be obtained.

[0164] In the above case, the optical distance between the first electrode 101 and the second electrode 102 can be strictly defined as the total thickness from the reflective region of the first electrode 101 to the reflective region of the second electrode 102. However, since it is difficult to precisely determine the reflective regions of the first electrode 101 and the second electrode 102, the above-mentioned effect can be sufficiently achieved by assuming any position of the first electrode 101 and the second electrode 102 as the reflective region. Furthermore, the optical distance between the first electrode 101 and the light-emitting layer from which desired light is obtained can be strictly defined as the optical distance between the reflective region of the first electrode 101 and the light-emitting region of the light-emitting layer from which desired light is obtained. However, since it is difficult to precisely determine the reflective region of the first electrode 101 and the light-emitting region of the light-emitting layer from which desired light is obtained, the above-mentioned effect can be sufficiently achieved by assuming any position of the first electrode 101 as the reflective region and any position of the light-emitting layer from which desired light is obtained as the light-emitting region.

[0165] The light-emitting device shown in Figure 2(D) has a tandem structure and a microcavity structure. When light-emitting layers with different emission colors are used for each EL layer (103a, 103b), light of the desired wavelength (monochromatic light) from either of the light-emitting layers can be extracted. Therefore, by using such a light-emitting device in a light-emitting device and adjusting the microcavity structure so that light of different wavelengths can be extracted from each subpixel, separate coloring (e.g., RGB) to obtain different emission colors is not required. This facilitates high-resolution display. It can also be combined with a colored layer (color filter). Furthermore, it is possible to enhance the emission intensity of a specific wavelength in the front direction, thereby reducing power consumption.

[0166] The light-emitting device shown in FIG. 2(E) is an example of the tandem-structure light-emitting device shown in FIG. 2(B). As shown in the figure, the light-emitting device has a structure in which three EL layers (103a, 103b, 103c) are stacked with charge generation layers (106a, 106b) sandwiched between them. Each of the three EL layers (103a, 103b, 103c) has a light-emitting layer (113a, 113b, 113c), and the light-emitting colors of the light-emitting layers can be freely combined. For example, the light-emitting layer 113a can be blue, the light-emitting layer 113b can be red, green, or yellow, and the light-emitting layer 113c can be blue. Alternatively, the light-emitting layer 113a can be red, the light-emitting layer 113b can be blue, green, or yellow, and the light-emitting layer 113c can be red.

[0167] In the light-emitting device according to one embodiment of the present invention, at least one of the first electrode 101 and the second electrode 102 is a light-transmitting electrode (such as a transparent electrode or a semi-transmitting / semi-reflective electrode). When the light-transmitting electrode is a transparent electrode, the visible light transmittance of the transparent electrode is 40% or more. In addition, when the semi-transmitting / semi-reflective electrode is used, the visible light reflectance of the semi-transmitting / semi-reflective electrode is 20% or more and 80% or less, preferably 40% or more and 70% or less. Furthermore, these electrodes have a resistivity of 1×10 -2 It is preferable to set it to Ωcm or less.

[0168] In the above-described light-emitting device according to one embodiment of the present invention, when one of the first electrode 101 and the second electrode 102 is a reflective electrode (a reflective electrode), the reflectivity of the reflective electrode for visible light is set to 40% to 100%, preferably 70% to 100%. -2 It is preferable to set it to Ωcm or less.

[0169] <Specific structure of the light-emitting device> Next, a specific structure of a light-emitting device according to one embodiment of the present invention will be described. Here, a description will be given using FIG. 2(D) having a tandem structure. The single-structure light-emitting devices shown in FIGS. 2(A) and 2(C) also have the same EL layer structure. When the light-emitting device shown in FIG. 2(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-transmissive and semi-reflective electrode. Therefore, a single or multiple desired electrode materials can be used to form a single layer or a stacked layer. The second electrode 102 is formed by selecting an appropriate material after the EL layer 103b is formed.

[0170] <First Electrode and Second Electrode> The materials forming the first electrode 101 and the second electrode 102 can be any combination of the following materials, as long as they fulfill the functions of both electrodes described above. For example, metals, alloys, electrically conductive compounds, and mixtures thereof can be used. Specific examples include In-Sn oxide (also known as ITO), In-Si-Sn oxide (also known as ITSO), In-Zn oxide, and In-W-Zn oxide. Other metals that can be used include aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), and neodymium (Nd), as well as alloys containing any combination of these metals. Other examples that can be used include elements belonging to Group 1 or 2 of the periodic table (e.g., lithium (Li), cesium (Cs), calcium (Ca), and strontium (Sr)), rare earth metals such as europium (Eu) and ytterbium (Yb), and alloys containing appropriate combinations of these elements, as well as graphene.

[0171] 2(D), when the first electrode 101 is an anode, the hole injection layer 111a and the hole transport layer 112a of the EL layer 103a are sequentially laminated by vacuum deposition on the first electrode 101. 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.

[0172] <Hole injection layer> The hole injection layer (111, 111a, 111b) is a layer that injects holes from the first electrode 101, which is an anode, and the charge generation layer (106, 106a, 106b) to the EL layer (103, 103a, 103b), and is a layer that contains an organic acceptor material and a material with high hole injection properties.

[0173] An organic acceptor material is a material that can generate holes in an organic compound by causing charge separation between the organic compound and another organic compound whose LUMO (Lowest Unoccupied Molecular Orbital) level and HOMO level are close to each other. Therefore, compounds having an electron-withdrawing group (halogen group or cyano group), such as quinodimethane derivatives, chloranil derivatives, and hexaazatriphenylene derivatives, can be used as the organic acceptor material. For example, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), 3,6-difluoro-2,5,7,7,8,8-hexacyanoquinodimethane, chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile, and the like can be used. Among organic acceptor materials, compounds such as HAT-CN, in which an electron-withdrawing group is bonded to a fused aromatic ring containing multiple heteroatoms, are particularly suitable because of their high acceptability and thermal stability. Radialene derivatives with electron-withdrawing groups (especially halogen groups such as fluoro groups or cyano groups) are also preferred because of their extremely high electron-accepting properties. Specific examples include α,α',α''-1,2,3-cyclopropanetriylidenetris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidenetris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], and α,α',α''-1,2,3-cyclopropanetriylidenetris[2,3,4,5,6-pentafluorobenzeneacetonitrile].

[0174] In addition, as a material with high hole injection properties, oxides of metals belonging to Groups 4 to 8 of the periodic table (e.g., transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide) can be used. Specific examples include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among these, molybdenum oxide is preferred because it is stable in the air, has low hygroscopicity, and is easy to handle. Other examples include phthalocyanine-based compounds such as phthalocyanine (abbreviated as HPc) and copper phthalocyanine (abbreviated as CuPc).

[0175] In addition to the above materials, we also have low molecular weight compounds such as 4,4',4''-tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4',4''-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: MTDATA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviation: DNTPD), and 1,3,5- Aromatic amine compounds such as tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), 3-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), and 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1) can be used.

[0176] In addition, polymeric compounds (oligomers, dendrimers, polymers, etc.) such as poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD) can be used. Alternatively, polymeric compounds with added acids, such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (abbreviation: PEDOT / PSS) and polyaniline / poly(styrenesulfonic acid) (abbreviation: PAni / PSS), can also be used.

[0177] Furthermore, a mixed material containing a hole transport material and the above-mentioned organic acceptor material (electron accepting material) can also be used as the material with high hole injection properties. In this case, electrons are extracted from the hole transport material by the organic acceptor material, generating holes in the hole injection layer 111, and the holes are injected into the light-emitting layer 113 via the hole transport layer 112. Note that the hole injection layer 111 may be formed as a single layer made of a mixed material containing the hole transport material and the organic acceptor material (electron accepting material), or may be formed by laminating the hole transport material and the organic acceptor material (electron accepting material) as separate layers.

[0178] As for hole transporting materials, the hole mobility at a square root of the electric field strength [V / cm] of 600 is 1×10 -6 cm 2 A substance having a hole mobility of 1 / Vs or more is preferred. Note that other substances can be used as long as they have a higher hole transporting property than an electron transporting property.

[0179] As the hole-transporting material, a material with high hole-transporting properties such as a compound having a π-electron-rich heteroaromatic ring (for example, a carbazole derivative, a furan derivative, or a thiophene derivative) and an aromatic amine (an organic compound having an aromatic amine skeleton) is preferred.

[0180] Examples of the carbazole derivatives (organic compounds having a carbazole ring) include bicarbazole derivatives (for example, 3,3'-bicarbazole derivatives), aromatic amines having a carbazolyl group, and the like.

[0181] Specific examples of the bicarbazole derivatives (for example, 3,3′-bicarbazole derivatives) include 3,3′-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), 9,9′-bis(biphenyl-4-yl)-3,3′-bi-9H-carbazole (abbreviation: BisBPCz), 9,9′-bis(1,1′-biphenyl-3-yl)-3,3′-bi-9H-carbazole (abbreviation: BismBPCz), 9-(1,1′-biphenyl-3-yl)-9′-(1,1′-biphenyl-4-yl)-9H,9′H-3,3′-bicarbazole (abbreviation: mBPCCBP), and 9-(2-naphthyl)-9′-phenyl-9H,9′H-3,3′-bicarbazole (abbreviation: βNCCP).

[0182] Specific examples of the aromatic amine having a carbazolyl group include 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazol-3-amine (abbreviation: PCBiF), N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBiF), and N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBiF). Abbreviation: PCBBiF), N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-bis(9,9-dimethyl-9H-fluoren-2-yl)amine (abbreviation: PCBFF), N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-4-amine, N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-(9,9-dimethyl-9H-fluoren-2-yl)-9,9-dimethyl-9H-fluoren N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-diphenyl-9H-fluoren-2-amine, N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-diphenyl-9H-fluoren-4-amine, N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi(9H-fluorene) )-2-amine, N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi(9H-fluoren)-4-amine, N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-(1,1':3',1''-terphenyl-4-yl)-9,9-dimethyl-9H-fluoren-2-amine, N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-(1,1':4',1''-terphenyl-4-yl)-9,9-Dimethyl-9H-fluoren-2-amine, N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-(1,1':3',1''-terphenyl-4-yl)-9,9-dimethyl-9H-fluoren-4-amine, N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-(1,1':4',1''-terphenyl-4-yl)-9,9-dimethyl-9H-fluoren-4-amine, 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine amine (abbreviated as PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviated as PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviated as PCBNBB), 4-phenyldiphenyl-(9-phenyl-9H-carbazol-3-yl)amine (abbreviated as PCA1BP), N,N'-bis(9-phenylcarbazol-3-yl)-N,N'-diphenylbenzene-1,3-diamine (abbreviated as PCBBi1BP), N,N',N''-triphenyl-N,N',N''-tris(9-phenylcarbazol-3-yl)benzene-1,3,5-triamine (abbreviation: PCA3B), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]spiro-9,9'-bifluoren-2-amine (abbreviation: PCBASF), 3-[N-(9-phenyl carbazole-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-naphthyl)amino]-9-phenylcarbazole (abbreviation: PCzTPN2), 2-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: PCAS F), N-[4-(9H-carbazol-9-yl)phenyl]-N-(4-phenyl)phenylaniline (abbreviation: YGA1BP), N,N'-bis[4-(carbazol-9-yl)phenyl]-N,N'-diphenyl-9,9-dimethylfluorene-2,7-diamine (abbreviation: YGA2F), 4,4',4''-tris(carbazol-9-yl)triphenylamine (abbreviation: TCTA), etc.

[0183] In addition to the above, examples of the carbazole derivatives include 3-[4-(9-phenanthryl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPPn), 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviation: TCPB), and 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA).

[0184] Specific examples of the furan derivatives (organic compounds having a furan ring) include 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II).

[0185] Specific examples of the thiophene derivatives (organic compounds having a thiophene ring) include 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV).

[0186] Specific examples of the aromatic amine include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB or α-NPD), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviation: TPD), 4,4'-bis[N-(spiro-9,9'-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), and 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP). '-(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''-diphenyltriphenylamine amine (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)naphthalene 4,4'-Diphenyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (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'-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazol-9-yl)phenyl]tris(1, 1'-biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazol-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N-bis([1,1'-biphenyl-4-yl]amine) N-(1,1'-biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), N,N-bis(9,9-dimethyl-9H-fluorene-2- N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-1-amine, and the like are mentioned.

[0187] Other examples of hole-transporting materials that can be used include polymeric compounds (oligomers, dendrimers, polymers, etc.) such as poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD). Alternatively, polymeric compounds containing added acids, such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (abbreviation: PEDOT / PSS) and polyaniline / poly(styrenesulfonic acid) (abbreviation: PAni / PSS), can also be used.

[0188] However, the hole transporting material is not limited to the above, and one or more of various known materials may be used as the hole transporting material.

[0189] The hole injection layers (111, 111a, 111b) can be formed using various known film formation methods, for example, vacuum deposition.

[0190] <Hole transport layer> The hole transport layers (112, 112a, 112b) are layers that transport holes injected from the first electrode 101 by the hole injection layers (111, 111a, 111b) to the light-emitting layers (113, 113a, 113b). The hole transport layers (112, 112a, 112b) are layers that contain a hole transport material. Therefore, the hole transport layers (112, 112a, 112b) can use the same hole transport material that can be used for the hole injection layers (111, 111a, 111b).

[0191] In the light-emitting device of one embodiment of the present invention, the light-emitting layers (113, 113a, 113b, and 113c) can be formed using the same organic compound as that used in the hole-transport layers (112, 112a, and 112b). It is more preferable to use the same organic compound in the hole-transport layers (112, 112a, and 112b) and the light-emitting layers (113, 113a, 113b, and 113c) because holes can be efficiently transported from the hole-transport layers (112, 112a, and 112b) to the light-emitting layers (113, 113a, 113b, and 113c).

[0192] <Light-emitting layer> The light-emitting layers (113, 113a, 113b, 113c) are layers containing light-emitting substances. Light-emitting substances that can be used for the light-emitting layers (113, 113a, 113b, 113c) include substances that emit light of colors such as blue, purple, blue-purple, green, yellow-green, yellow, orange, and red. When multiple light-emitting layers are provided, different light-emitting substances can be used for each light-emitting layer to produce different light-emitting colors (for example, white light emission obtained by combining complementary light-emitting colors). Furthermore, a stacked structure in which each light-emitting layer contains different light-emitting substances may be used.

[0193] Furthermore, the light-emitting layers (113, 113a, 113b, 113c) may contain one or more organic compounds (host materials, etc.) in addition to the light-emitting substance (guest material).

[0194] When multiple host materials are used in the light-emitting layers (113, 113a, 113b, and 113c), it is preferable to use a substance having a larger energy gap as the second host material than the energy gaps of the existing guest material and the first host material. Furthermore, it is preferable that the lowest singlet excitation level (S1 level) of the second host material is higher than the S1 level of the first host material, and the lowest triplet excitation 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 level (T1 level) of the second host material is higher than the T1 level of the first host material. With this structure, an exciplex can be formed using two types of host materials. To efficiently form an exciplex, it is particularly preferable to combine a compound that easily accepts holes (hole-transporting material) with a compound that easily accepts electrons (electron-transporting material). Furthermore, this structure can simultaneously achieve high efficiency, low voltage, and long life.

[0195] The organic compounds used as the host materials (including the first host material and the second host material) may be hole-transporting materials usable in the hole-transporting layers (112, 112a, and 112b) described above or electron-transporting materials usable in the electron-transporting layers (114, 114a, and 114b) described below, as long as they satisfy the requirements for a host material used in an emitting layer. These organic compounds may also be exciplexes composed of multiple organic compounds (the first host material and the second host material described above). An exciplex (also referred to as an exciplex) formed by multiple organic compounds in an excited state has an extremely small difference between the S1 and T1 levels and functions as a TADF material capable of converting triplet excitation energy into singlet excitation energy. A combination of multiple organic compounds that form an exciplex is preferably one in which one of the compounds has a π-electron-deficient heteroaromatic ring and the other has a π-electron-rich heteroaromatic ring. As a combination for forming an exciplex, one of the compounds may be a phosphorescent material such as an iridium, rhodium, or platinum-based organometallic complex or a metal complex.

[0196] There are no particular limitations on the light-emitting substances that can be used in the light-emitting layers (113, 113a, 113b), and light-emitting substances that convert singlet excitation energy into light emission in the visible light range, or light-emitting substances that convert triplet excitation energy into light emission in the visible light range, can be used.

[0197] <Light-emitting material that converts singlet excitation energy into light> Examples of luminescent materials that convert singlet excitation energy into luminescence and can be used in the luminescent layers (113, 113a, 113b) include the following fluorescent substances (fluorescent luminescent materials): pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives. Pyrene derivatives are particularly preferred because of their high 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, N'-diphenylpyrene-1,6-diamine (abbreviation: 1,6ThAPrn), N,N'-(pyrene-1,6-diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-6-amine] (abbreviation: 1,6BnfAPrn), N,N'-(pyrene-1,6-diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-02), N,N'-(pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), and the like.

[0198] In addition, 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2,2'-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl-9-anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2BPy), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)phenyl N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), 4-(10-phenyl-9-anthryl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), 4-(10-phenyl-9-anthryl)-4'- (9-Phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), 4-[4-(10-phenyl-9-anthryl)phenyl]-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPBA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenyl) N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: 2PCAPPA), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), and the like can be used.

[0199] In addition, N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(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-carbazol-9-yl)phenyl]-N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracen-9-amine (abbreviation: DPhAPhA), Coumarin 545T, N,N'-diphenylquinacridone (abbreviation: DPQd), rubrene, 5,12-bis(1,1'-biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyran-4-yl) N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhTD), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM2), N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p -mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB),6-Bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJTM), 1,6BnfAP rn-03, 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviated as 3,10PCA2Nbf(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviated as 3,10FrA2Nbf(IV)-02), etc. In particular, pyrene diamine compounds such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03 can be used.

[0200] <Light-emitting material that converts triplet excitation energy into light> Next, examples of luminescent materials that can be used in the luminescent layer 113 and convert triplet excitation energy into luminescence include phosphorescent materials and thermally activated delayed fluorescence (TADF) materials that exhibit thermally activated delayed fluorescence.

[0201] A phosphorescent material is a compound that exhibits phosphorescence but does not exhibit fluorescence at a temperature range from low temperatures (e.g., 77 K) to room temperature (i.e., 77 K to 313 K). The phosphorescent material preferably contains a metal element with a large spin-orbit interaction, such as an organometallic complex, a metal complex (platinum complex), or a rare-earth metal complex. Specifically, a transition metal element is preferred, and a platinum group element (ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), or platinum (Pt)) is particularly preferred. Among these, iridium is preferred because it can increase the transition probability associated with the direct transition between the singlet ground state and the triplet excited state.

[0202] <Phosphorescent material (450nm to 570nm: blue or green)> Examples of phosphorescent materials that exhibit blue or green light and have an emission spectrum with a peak wavelength of 450 nm or more and 570 nm or less include the following materials.

[0203] For example, tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN 2]phenyl-κC}iridium(III) (abbreviation: [Ir(mpptz-dmp)3]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Mptz)3]), tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviation: organometallic complexes containing a 4H-triazole ring, such as tris[3-(5-biphenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(iPr5btz)3]), tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(iPr5btz)3]), ]iridium(III) (abbreviation: [Ir(Mptz1-mp)3]), organometallic complexes containing a 1H-triazole ring such as tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Prptz1-Me)3]), organometallic complexes containing an imidazole ring such as fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpmi)3]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me)3]), and bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2 ']iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2 ']iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinato-N,C 2’}iridium(III) picolinate (abbreviation: [Ir(CF3ppy)2(pic)]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’] Organometallic complexes with a phenylpyridine derivative having an electron-withdrawing group as a ligand, such as iridium(III) acetylacetonate (abbreviation: FIr(acac)), are also included.

[0204] <Phosphorescent material (495nm to 590nm: green or yellow)> Examples of phosphorescent materials that exhibit green or yellow color and have an emission spectrum with a peak wavelength of 495 nm or more and 590 nm or less include the following materials.

[0205] For example, tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)3]), tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)3]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)2(acac)]), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [I r(tBuppm)2(acac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm)2(acac)]), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(mpmppm)2(acac)]), (acetylacetonato)bis{4,6-dimethyl-2-[6-(2,6-dimethylphenyl)-4-pyrimidinyl-κN 3]phenyl-κC}iridium(III) (abbreviation: [Ir(dmppm-dmp)2(acac)]), organometallic iridium complexes containing a pyrimidine ring, such as (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2(acac)]), organometallic iridium complexes containing a pyrazine ring, such as (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-Me)2(acac)]), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-iPr)2(acac)]), and tris(2-phenylpyridinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(ppy)3]), bis(2-phenylpyridinato-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: [Ir(ppy)2(acac)]), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: [Ir(bzq)2(acac)]), tris(benzo[h]quinolinato)iridium(III) (abbreviation: [Ir(bzq)3]), tris(2-phenylquinolinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(pq)3]), bis(2-phenylquinolinato-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: [Ir(pq)2(acac)]), bis[2-(2-pyridinyl-κN)phenyl-κC][2-(4-phenyl-2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy)2(4dppy)]), bis[2-(2-pyridinyl-κN)phenyl-κC][2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC], [2-d3-methyl-8-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN 2)phenyl-κC]iridium(III) (abbreviation: Ir(5mppy-d3)2(mbfpypy-d3)), [2-(methyl-d3)-8-[4-(1-methylethyl-1-d)-2-pyridinyl-κN]benzofuro[2,3-b]pyridin-7-yl-κC]bis[5-(methyl-d3)-2-[5-(methyl-d3)-2-pyridinyl-κN]phenyl-κC]iridium(III) (abbreviation: Ir(5mtpy-d6)2(mbfpypy-iPr-d4)), [2-d3-methyl-(2-pyridinyl organometallic iridium complexes containing a pyridine ring, such as [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviated as Ir(ppy)2(mbfpypy-d3)), [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviated as Ir(ppy)2(mdppy)), and bis(2,4-diphenyl-1,3-oxazolato-N,C) 2’ ) Iridium(III) acetylacetonate (abbreviation: [Ir(dpo)2(acac)]), bis{2-[4'-(perfluorophenyl)phenyl]pyridinato-N,C 2’}Iridium(III) acetylacetonate (abbreviation: [Ir(p-PF-ph)2(acac)]), bis(2-phenylbenzothiazolato-N,C 2’ ) iridium(III) acetylacetonate (abbreviated as [Ir(bt)2(acac)]), as well as rare earth metal complexes such as tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviated as [Tb(acac)3(Phen)]).

[0206] <Phosphorescent materials (570nm to 750nm: yellow or red)> Examples of phosphorescent materials that exhibit yellow or red color and have an emission spectrum with a peak wavelength of 570 nm or more and 750 nm or less include the following materials.

[0207] For example, pyrimidinato]iridium(III) such as (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(5mdppm)2(dpm)]), and (dipivaloylmethanato)bis[4,6-di(naphthalen-1-yl)pyrimidinato]iridium(III) (abbreviation: [Ir(d1npm)2(dpm)]). Organometallic complexes containing an imidine ring, (acetylacetonato)bis(2,3,5-triphenylpyrazinato)iridium(III) (abbreviation: [Ir(tppr)2(acac)]), bis(2,3,5-triphenylpyrazinato)(dipivaloylmethanato)iridium(III) (abbreviation: [Ir(tppr)2(dpm)]), and bis{4,6-dimethyl-2-[3-(3,5-dimethylphenyl)-5-phenyl-2-pyrazinyl-κN]phenyl-κC}(2,6-dimethyl-3,5-heptanedionato-κN). 2 O,O')iridium(III) (abbreviation: [Ir(dmdppr-P)2(dibm)]), bis{4,6-dimethyl-2-[5-(4-cyano-2,6-dimethylphenyl)-3-(3,5-dimethylphenyl)-2-pyrazinyl-κN]phenyl-κC}(2,2,6,6-tetramethyl-3,5-heptanedionato-κ) 2 O,O')iridium(III) (abbreviation: [Ir(dmdppr-dmCP)2(dpm)]), bis[2-(5-(2,6-dimethylphenyl)-3-(3,5-dimethylphenyl)-2-pyrazinyl-κN)-4,6-dimethylphenyl-κC](2,2',6,6'-tetramethyl-3,5-heptanedionato-κO,O')iridium(III) (abbreviation: [Ir(dmdppr-dmp)2(dpm)]), (acetylacetonato)bis[2-methyl-3-phenylquinoxalinato-N,C 2’ ]iridium(III) (abbreviation: [Ir(mpq)2(acac)]), (acetylacetonato)bis(2,3-diphenylquinoxalinato-N,C 2’)iridium(III) (abbreviation: [Ir(dpq)2(acac)]), organometallic complexes with a pyrazine ring such as (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq)2(acac)]), tris(1-phenylisoquinolinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(piq)3]), bis(1-phenylisoquinolinato-N,C 2’ ) iridium(III) acetylacetonate (abbreviation: [Ir(piq)2(acac)]), and bis[4,6-dimethyl-2-(2-quinolinyl-κN)phenyl-κC](2,4-pentanedionato-κ 2 These include organometallic complexes with a pyridine ring, such as (O,O')iridium(III) (abbreviation: [Ir(dmpqn)2(acac)]), platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrinplatinum(II) (abbreviation: [PtOEP]), and rare earth metal complexes such as tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: [Eu(DBM)3(Phen)]), and tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: [Eu(TTA)3(Phen)]).

[0208] ≪TADF material≫ The following materials can be used as TADF materials. TADF materials are materials 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 material efficiently emits light (fluorescence) from the singlet excited state. Conditions for efficiently obtaining thermally activated delayed fluorescence include an energy difference between the triplet excited level and the singlet excited level of 0 eV or more and 0.2 eV or less, preferably 0 eV or more and 0.1 eV or less. Delayed fluorescence in TADF materials refers to light emission that has a spectrum similar to that of normal fluorescence but has a significantly long lifetime. Its lifetime is 1×10-6 seconds or more, preferably 1 x 10 -3 More than a second.

[0209] Examples of TADF materials include fullerene and its derivatives, acridine derivatives such as proflavine, eosin, etc. Also included are metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd). Examples of metal-containing porphyrins include protoporphyrin-tin fluoride complex (abbreviation: SnF2(Proto IX)), mesoporphyrin-tin fluoride complex (abbreviation: SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (abbreviation: SnF2(Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (abbreviation: SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complex (abbreviation: SnF2(OEP)), etioporphyrin-tin fluoride complex (abbreviation: SnF2(Etio I)), and octaethylporphyrin-platinum chloride complex (abbreviation: PtCl2OEP).

[0210] [ka]

[0211] Other examples include 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2-[4-(10H-phenoxy) 3-[4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN), bis[4-(9, 9-Dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthracen]-10'-one (abbreviation: ACRSA), 4-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)benzofuro[3,2-d]pyrimidine (abbreviation: 4PCCzBfpm), 4-[4-(9'-phenyl-3,3'- Heteroaromatic compounds having a π-electron rich heteroaromatic compound and a π-electron deficient heteroaromatic compound, such as 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), may also be used.

[0212] In addition, a substance in which a π-electron-rich heteroaromatic compound and a π-electron-deficient heteroaromatic compound are directly bonded is particularly preferable because the donor property of the π-electron-rich heteroaromatic compound and the acceptor property of the π-electron-deficient heteroaromatic compound are both strong, thereby reducing the energy difference between the singlet excited state and the triplet excited state. Furthermore, a TADF material (TADF100) in which the singlet excited state and the triplet excited state are in thermal equilibrium may also be used as the TADF material. Such TADF materials have a short emission lifetime (excitation lifetime), which can suppress efficiency decline in light-emitting devices in the high-brightness range.

[0213] [ka]

[0214] In addition to the above, examples of materials capable of converting triplet excitation energy into luminescence include nanostructures of transition metal compounds having a perovskite structure. Nanostructures of metal halide perovskites are particularly preferred. Nanoparticles and nanorods are preferred as such nanostructures.

[0215] In the light-emitting layers (113, 113a, 113b, 113c), one or more substances having an energy gap larger than the energy gap of the light-emitting substance (guest material) may be selected and used as the organic compound (host material, etc.) used in combination with the above-mentioned light-emitting substance (guest material).

[0216] <Fluorescent host material> When the light-emitting substance used in the light-emitting layers (113, 113a, 113b, and 113c) is a fluorescent light-emitting substance, it is preferable to use, as the organic compound (host material) to be combined, an organic compound having a high energy level in a singlet excited state and a low energy level in a triplet excited state, or an organic compound with a high fluorescence quantum yield. Therefore, as long as an organic compound satisfies these conditions, a hole-transporting material (described above) and an electron-transporting material (described below) shown in this embodiment can be used. In addition, the fluorescent host material can be used as the first organic compound described in Embodiment 1.

[0217] Although some of the examples overlap with those described above, examples of the organic compound (host material) that can be preferably combined with the light-emitting substance (fluorescent light-emitting substance) include condensed polycyclic aromatic compounds such as anthracene derivatives, tetracene derivatives, phenanthrene derivatives, pyrene derivatives, chrysene derivatives, and dibenzo[g,p]chrysene derivatives.

[0218] Specific examples of organic compounds (host materials) that are preferably used in combination with fluorescent materials include 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA), 3,6-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: DPCzPA), 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 9,10-diphenylanthracene (abbreviation: DPAnth), N,N ... N-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-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-carbazol-3-amine (abbreviation: PCAPBA), N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazol-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]-benzyl benzo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10-{4-(9-phenyl-9H-fluoren-9-yl)-biphenyl-4'-yl}-anthracene (abbreviation: FLPPA), 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviation: α,β-ADN), 2-(10-phenylanthracen-9-yl)dibenzofuran, 2-(10-phenyl-9-anthracenyl)-benzo[b]naphtho[2,3-d]furan (abbreviated as Bnf(II)PhA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviated as αN-βNPAnth), 2,9-di(1-naphthyl)-10-phenylanthracene (abbreviated as 2αN-αNPhA), 9 -(1-naphthyl)-10-[3-(1-naphthyl)phenyl]anthracene (abbreviation: αN-mαNPAnth), 9-(2-naphthyl)-10-[3-(1-naphthyl)phenyl]anthracene (abbreviation: βN-mαNPAnth), 9-(1-naphthyl)-10-[4-(1-naphthyl)phenyl]anthracene (abbreviation: αN-αNPAnth), 9-(2-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene anthracene (abbreviation: βN-βNPAnth), 2-(1-naphthyl)-9-(2-naphthyl)-10-phenylanthracene (abbreviation: 2αN-βNPhA), 9-(2-naphthyl)-10-[3-(2-naphthyl)phenyl]anthracene (abbreviation: βN-mβNPAnth), 1-[4-(10-[1,1'-biphenyl]-4-yl-9-anthracenyl)phenyl]-2-ethyl-1H-benzimidazole (abbreviation: E tBImPBPhA), 9,9'-bianthryl (abbreviated as BANT), 9,9'-(stilbene-3,3'-diyl)diphenanthrene (abbreviated as DPNS), 9,9'-(stilbene-4,4'-diyl)diphenanthrene (abbreviated as DPNS2), 1,3,5-tri(1-pyrenyl)benzene (abbreviated as TPB3), 5,12-diphenyltetracene, 5,12-bis(biphenyl-2-yl)tetracene, etc.

[0219] <Phosphorescent host material> Furthermore, when the light-emitting substance used in the light-emitting layers (113, 113a, 113b, 113c) is a phosphorescent light-emitting substance, an organic compound having a triplet excitation energy greater than the triplet excitation energy (energy difference between the ground state and the triplet excited state) of the light-emitting substance can be selected as the organic compound (host material) to be combined. Note that when multiple organic compounds (for example, a first host material and a second host material (or assist material)) are used in combination with the light-emitting substance to form an exciplex, it is preferable to use these multiple organic compounds in combination with the phosphorescent light-emitting substance.

[0220] With this structure, it is possible to efficiently obtain light emission using Exciplex-Triplet Energy Transfer (ExTET), which is an energy transfer from an exciplex to a light-emitting substance. As a combination of multiple organic compounds, it is preferable to use one that easily forms an exciplex, and it is particularly preferable to combine a compound that easily accepts holes (hole transport material) with a compound that easily accepts electrons (electron transport material).

[0221] Although some of the examples overlap with those described above, from the viewpoint of a preferable combination with the light-emitting substance (phosphorescent light-emitting substance), examples of the organic compound (host material, assist material) include aromatic amines (organic compounds having an aromatic amine skeleton), carbazole derivatives (organic compounds having a carbazole ring), dibenzothiophene derivatives (organic compounds having a dibenzothiophene ring), dibenzofuran derivatives (organic compounds having a dibenzofuran ring), oxadiazole derivatives (organic compounds having an oxadiazole ring), triazole derivatives (organic compounds having a triazole ring), benzimidazole derivatives (benzoyl midazole ring), quinoxaline derivatives (organic compounds having a quinoxaline ring), dibenzoquinoxaline derivatives (organic compounds having a dibenzoquinoxaline ring), pyrimidine derivatives (organic compounds having a pyrimidine ring), triazine derivatives (organic compounds having a triazine ring), pyridine derivatives (organic compounds having a pyridine ring), bipyridine derivatives (organic compounds having a bipyridine ring), phenanthroline derivatives (organic compounds having a phenanthroline ring), furodiazine derivatives (organic compounds having a furodiazine ring), zinc- and aluminum-based metal complexes, and the like.

[0222] Among the organic compounds, specific examples of the aromatic amine and carbazole derivative, which are organic compounds with high hole-transporting properties, include the same as the specific examples of the hole-transporting material described above, and any of these is preferable as the host material.

[0223] Specific examples of the dibenzothiophene derivatives and dibenzofuran derivatives, which are organic compounds with high hole transport properties among the above organic compounds, include 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II), DBT3P-II, 2,8-dipheny Examples of suitable host materials include 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), and 4-[3-(triphenylen-2-yl)phenyl]dibenzothiophene (abbreviation: mDBTPTp-II).

[0224] Other preferred host materials include metal complexes having oxazole- or thiazole-based ligands, such as bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO) and bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ).

[0225] Specific examples of the organic compounds having high electron transport properties, such as oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, quinazoline derivatives, and phenanthroline derivatives, among the above organic compounds, include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl [3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4'-bis(5-methylbenzoxazoline) organic compounds containing heteroaromatic rings with polyazole rings, such as 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2-(1,3-phenylene)bis[9-phenyl-1,10-phenanthroline] (abbreviation: mPPhen2P), 2-phenyl-9-[4-[4-(9-phenyl-1,10-phenanthrolin-2-yl)phenyl]phenyl]- Organic compounds containing heteroaromatic rings with a pyridine ring, such as 1,10-phenanthroline (abbreviated as PPhen2BP), 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviated as 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviated as 2mCzBPDBq), and 2-[4-(3,6-diphenyl-9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as 7mDBTPDBq-II), and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as 6mDBTPDB q-II), 2-{4-[9,10-di(2-naphthyl)-2-anthryl]phenyl}-1-phenyl-1H-benzimidazole (abbreviation: ZADN), 2-[4'-(9-phenyl-9H-carbazol-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), etc., all of which are preferred as host materials.

[0226] Furthermore, among the above organic compounds, specific examples of organic compounds with high electron transport properties, such as pyridine derivatives, diazine derivatives (including pyrimidine derivatives, pyrazine derivatives, and pyridazine derivatives), triazine derivatives, and furodiazine derivatives, include 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-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), and 4,6-bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II). abbreviation: 4,6mCzP2Pm), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri [3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), 9,9'-[pyrimidine-4,6-diylbis(biphenyl-3,3'-diyl)]bis(9H-carbazole) (abbreviation: 4,6mCzBP2Pm), 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)-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]benzofuro[3, 2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 9-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 9-[3'-(dibenzothiophen-4-yl)biphenyl-4-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9pmDBtBPNfpr), 11-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]phenanthro[9',10':4,5]furo[2,3-b]pyrazine (abbreviation: 11mDBtBPPnfpr), 11-[3'-(dibenzothiophen-4-yl)biphenyl-4-yl]phenanthro[9',10':4,5]furo[2,3-b]pyrazine, 11-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]phenanthro[9',10':4,5]furo[2,3-b]pyrazine, 12-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)phenanthro[9',10':4,5]furo[2,3-b]pyrazine (abbreviation: 12PCCzPnfpr), 9-[(3'-9- phenyl-9H-carbazol-3-yl)biphenyl-4-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviated as 9pmPCBPNfpr), 9-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviated as 9PCCzNfpr), 10-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviated as 10PCCzNfpr), 9-[3'-(6-phenylbenzo[b]naphtho[ 1,2-d]furan-8-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mBnfBPNfpr), 9-{3-[6-(9,9-dimethylfluoren-2-yl)dibenzothiophen-4-yl]phenyl}naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mFDBtPNfpr), 9-[3'-(6-phenyldibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr-02), 9- [3-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)phenyl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mPCCzPNfpr), 9-{(3'-[2,8-diphenyldibenzothiophen-4-yl]biphenyl-3-yl}naphtho[1',2':4,5]furo[2,3-b]pyrazine, 11-{(3'-[2,8-diphenyldibenzothiophen-4-yl]biphenyl-3-yl}phenanthro[9',10':4,5]furo[2,3-b]pyrazine, 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-[3'-(triphenylen-2-yl)-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'-spirobi(9H-fluoren)-2-yl]-1,3,5-triazine (abbreviation: BP-SFTzn), 2,6-bis(4-naphthalen-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]-9-furan Examples of suitable host materials include organic compounds containing heteroaromatic rings with diazine rings, such as phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-[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), 6-(1,1'-biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), and 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(1,1'-biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm).

[0227] Furthermore, among the above organic compounds, specific examples of metal complexes, which are organic compounds with high electron-transporting properties, include zinc- or aluminum-based metal complexes such as tris(8-quinolinolato)aluminum(III) (abbreviation: Alq), tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), and bis(8-quinolinolato)zinc(II) (abbreviation: Znq), as well as metal complexes having a quinoline ring or a benzoquinoline ring, all of which are preferable as the host material.

[0228] Other preferred host materials include polymer compounds such as poly(2,5-pyridinediyl) (abbreviation: PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviation: PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviation: PF-BPy).

[0229] Furthermore, we have developed bipolar organic compounds with high hole-transporting and electron-transporting properties, such as 9-phenyl-9'-(4-phenyl-2-quinazolinyl)-3,3'-bi-9H-carbazole (abbreviation: PCCzQz), 2-[4'-(9-phenyl-9H-carbazol-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1 Organic compounds having a diazine ring, such as 11-(4-[1,1'-biphenyl]-4-yl-6-phenyl-1,3,5-triazin-2-yl)-11,12-dihydro-12-phenyl-indolo[2,3-a]carbazole (abbreviation: mINc(II)PTzn), 11-(4-[1,1'-biphenyl]-4-yl-6-phenyl-1,3,5-triazin-2-yl)-11,12-dihydro-12-phenyl-indolo[2,3-a]carbazole (abbreviation: BP-Icz(II)Tzn), and 7-[4-(9-phenyl-9H-carbazol-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: PC-cgDBCzQz), can also be used as the host material.

[0230] <Electron transport layer> The electron transport layers (114, 114a, 114b) are layers that transport electrons injected from the second electrode 102 and the charge generation layers (106, 106a, 106b) by the electron injection layers (115, 115a, 115b) described later to the light-emitting layers (113, 113a, 113b). Note that the light-emitting device according to one embodiment of the present invention can have improved heat resistance when the electron transport layer has a stacked structure. In addition, the electron transport material used for the electron transport layers (114, 114a, 114b) has an electron mobility of 1×10 or more at a square root of an electric field strength [V / cm] of 600. -6 cm 2A substance having an electron mobility of 1 / Vs or higher is preferred. Note that other substances can be used as long as they have a higher electron transporting property than hole transporting property. The electron transport layer (114, 114a, 114b) functions as a single layer, but may also have a stacked structure of two or more layers. Note that the above mixed materials have heat resistance, so that by performing a photolithography process on the electron transport layer using such a mixed material, the influence of a thermal process on the device characteristics can be suppressed.

[0231] ≪Electron transport material≫ The electron transport material usable for the electron transport layer (114, 114a, 114b) can be an organic compound with high electron transport properties, such as a heteroaromatic compound. A heteroaromatic compound is a cyclic compound containing at least two different elements in the ring. The ring structure can be a three-, four-, five-, or six-membered ring, with a five- or six-membered ring being particularly preferred. The element contained therein is preferably a heteroaromatic compound containing one or more of nitrogen, oxygen, or sulfur in addition to carbon. Nitrogen-containing heteroaromatic compounds (nitrogen-containing heteroaromatic compounds) are particularly preferred, and it is preferable to use a material with high electron transport properties (electron transport material) such as a nitrogen-containing heteroaromatic compound or a π-electron-deficient heteroaromatic compound containing such a nitrogen-containing heteroaromatic compound. It is preferable to use a material different from the material used for the light-emitting layer. Not all of the excitons generated by carrier recombination in the light-emitting layer can contribute to light emission; they may diffuse to layers adjacent to or nearby the light-emitting layer. To avoid this phenomenon, it is preferable that the energy level (lowest singlet excitation level or lowest triplet excitation level) of the material used in the layer adjacent to or near the light-emitting layer is higher than that of the material used in the light-emitting layer. Therefore, to obtain a highly efficient device, it is preferable that the electron-transporting material is different from the material used in the light-emitting layer.

[0232] A heteroaromatic compound is an organic compound that contains at least one heteroaromatic ring.

[0233] The heteroaromatic ring has any one of a pyridine ring, a diazine ring, a triazine ring, a polyazole ring, an oxazole ring, a thiazole ring, etc. The heteroaromatic ring having a diazine ring includes a heteroaromatic ring having a pyrimidine ring, a pyrazine ring, a pyridazine ring, etc. The heteroaromatic ring having a polyazole ring includes a heteroaromatic ring having an imidazole ring, a triazole ring, or an oxadiazole ring.

[0234] The heteroaromatic ring also includes a fused heteroaromatic ring having a fused ring structure, such as a quinoline ring, a benzoquinoline ring, a quinoxaline ring, a dibenzoquinoxaline ring, a quinazoline ring, a benzoquinazoline ring, a dibenzoquinazoline ring, a phenanthroline ring, a phlodiazin ring, or a benzimidazole ring.

[0235] Among heteroaromatic compounds containing one or more of nitrogen, oxygen, and sulfur in addition to carbon, examples of heteroaromatic compounds having a five-membered ring structure include heteroaromatic compounds having an imidazole ring, heteroaromatic compounds having a triazole ring, heteroaromatic compounds having an oxazole ring, heteroaromatic compounds having an oxadiazole ring, heteroaromatic compounds having a thiazole ring, and heteroaromatic compounds having a benzimidazole ring.

[0236] Furthermore, among heteroaromatic compounds containing one or more of nitrogen, oxygen, and sulfur in addition to carbon, examples of heteroaromatic compounds having a six-membered ring structure include heteroaromatic compounds having a heteroaromatic ring such as a pyridine ring, a diazine ring (including a pyrimidine ring, a pyrazine ring, and a pyridazine ring), a triazine ring, and a polyazole ring.Heteroaromatic compounds having a structure in which pyridine rings are linked include heteroaromatic compounds having a bipyridine structure and heteroaromatic compounds having a terpyridine structure.

[0237] Furthermore, examples of heteroaromatic compounds having a fused ring structure partially containing the above-mentioned 6-membered ring structure include heteroaromatic compounds having a fused heteroaromatic ring such as a quinoline ring, a benzoquinoline ring, a quinoxaline ring, a dibenzoquinoxaline ring, a phenanthroline ring, a furodiazine ring (including a structure in which an aromatic ring is fused to the furan ring of a furodiazine ring), and a benzimidazole ring.

[0238] Specific examples of the heteroaromatic compound having a five-membered ring structure (such as a polyazole ring (including an imidazole ring, a triazole ring, and an oxadiazole ring), an oxazole ring, a thiazole ring, and a benzimidazole ring) include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 3-(4-biphenylyl)-4-furan (abbreviation: FURAN ... phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenylyl)-1,2,4-triazole (abbreviation: p-EtTAZ), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs), and the like.

[0239] Specific examples of the heteroaromatic compound having a 6-membered ring structure (including heteroaromatic rings having a pyridine ring, a diazine ring, a triazine ring, or the like) include heteroaromatic compounds having a pyridine ring, such as 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy) and 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB); -triazine (abbreviation: PCCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-[3'-(triphenylen-2-yl)-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'-spirobi(9H-fluoren)-2-yl]-1,3,5-triazine (abbreviation: BP-SFTzn), 2,6-bis(4-naphthalen-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-[1,1'-biphenyl]-4-yl-4-phenyl-6-[9,9'-spirobi(9H-fluoren)-2-yl]-1,3,5-triazine (abbreviation: BP-SFTzn), 2,6-bis(4-naphthalen-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviation: PCDBfTzn), Heteroaromatic compounds containing heteroaromatic rings with triazine rings, such as 2-{3-[3-(dibenzothiophen-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTzn), mFBPTzn, 4,6-bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), ...6-Bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviated as 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviated as 4,6mCzP2Pm), 4,6mCzBP2Pm, 6-(1,1'-biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviated as 6mBP-4Cz2 PPm), 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(1,1'-biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 4-[3-(dibenzothiophen-4-yl)phenyl]-8-(naphthalen-2-yl)-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8βN-4mDBtPBfpm), 8BP-4mDBtPBfpm, 9mDBtBP Nfpr, 9pmDBtBPNfpr, 3,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzofuro[2,3-b]pyrazine (abbreviated as 3,8mDBtP2Bfpr), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviated as 4,8mDBtP2Bfpm), 8-[3'-(dibenzothiophen-4-yl)(1,1'-biphenyl- and heteroaromatic compounds containing a heteroaromatic ring having a diazine (pyrimidine) ring, such as 8-[(2,2'-binaphthalen)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm). The aromatic compounds containing a heteroaromatic ring include heteroaromatic compounds having a fused heteroaromatic ring.

[0240] Other examples include 2,2'-(pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6(P-Bqn)2Py), 2,2'-(2,2'-bipyridine-6,6'-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 6,6'(P-Bqn)2BPy), 2,2'-(pyridine-2,6-diyl)bis{4-[4-(2-naphthyl)phenyl]-6-phenylpyrimidine} (abbreviation: 2,6(NP-PPm)2Py), and 6-(1,1'-biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6 mBP-4Cz2PPm), and other heteroaromatic compounds containing a heteroaromatic ring having a diazine (pyrimidine) ring; and 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine (abbreviation: TmPPPyTz), 2,4,6-tris(2-pyridyl)-1,3,5-triazine (abbreviation: 2Py3Tz), 2-[3-(2,6-dimethyl-3-pyridyl)-5-(9-phenanthrenyl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTzn), and other heteroaromatic compounds containing a heteroaromatic ring having a triazine ring.

[0241] Specific examples of the heteroaromatic compound having a fused ring structure partially containing a 6-membered ring structure (heteroaromatic compound having a fused ring structure) include bathophenanthroline (abbreviation: Bphen), bathocuproine (abbreviation: BCP), 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2-(1,3-phenylene)bis[9-phenyl-1,10-phenanthroline] (abbreviation: NBphen), mPPhen2P), 2-phenyl-9-[4-[4-(9-phenyl-1,10-phenanthrolin-2-yl)phenyl]phenyl]-1,10-phenanthroline (abbreviated as PPhen2BP), 2,2'-(pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviated as 2,6(P-Bqn)2Py), 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4-(3,6-diphenyl-9H-carbazol-9-yl)phenyl]dibenzo [f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 2mpPCBPDBq, and other heteroaromatic compounds having a quinoxaline ring are also included.

[0242] In addition to the heteroaromatic compounds described above, the electron transport layers (114, 114a, 114b) may also include the following metal complexes: metal complexes having a quinoline ring or a benzoquinoline ring, such as tris(8-quinolinolato)aluminum(III) (abbreviation: Alq3), Almq3, 8-quinolinolatolithium(I) (abbreviation: Liq), BeBq2, bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), and bis(8-quinolinolato)zinc(II) (abbreviation: Znq); and metal complexes having an oxazole ring or a thiazole ring, such as bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO) and bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ).

[0243] In addition, polymer compounds such as poly(2,5-pyridinediyl) (abbreviation: PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviation: PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviation: PF-BPy) can also be used as electron transport materials.

[0244] The electron transport layer (114, 114a, 114b) may be not only a single layer, but also a laminate structure of two or more layers made of the above-mentioned materials.

[0245] <Electron injection layer> The electron injection layers (115, 115a, 115b) are layers containing a substance with high electron injection properties. The electron injection layers (115, 115a, 115b) are layers for increasing the efficiency of electron injection from the second electrode 102, and it is preferable to use a material for the second electrode 102 having a work function whose difference in LUMO level is small (0.5 eV or less) compared with that of the material for the electron injection layers (115, 115a, 115b). Therefore, the electron injection layer 115 may contain any of lithium, cesium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF), Liq, 2-(2-pyridyl)phenolatolithium (abbreviated as LiPP), 2-(2-pyridyl)-3-pyridinolatolithium (abbreviated as LiPPy), 4-phenyl-2-(2-pyridyl)phenolatolithium (abbreviated as LiPPP), lithium oxide (LiO x Alkali metals, alkaline earth metals, such as cesium carbonate, or compounds thereof can be used. Rare earth metals, such as erbium fluoride (ErF3) or ytterbium (Yb), or rare earth metal compounds can also be used. The electron injection layers (115, 115a, 115b) may be formed by mixing a plurality of the above materials or by stacking a plurality of the above materials. Electrides may also be used for the electron injection layers (115, 115a, 115b). Examples of electrides include a substance in which a high concentration of electrons is added to a mixed oxide of calcium and aluminum. The substances constituting the above-mentioned electron transport layers (114, 114a, 114b) can also be used.

[0246] The electron injection layer (115, 115a, 115b) may also be made of a mixed material containing an organic compound and an electron donor (donor). Such a mixed material has excellent electron injection and electron transport properties because electrons are generated in the organic compound by the electron donor. In this case, the organic compound is preferably a material that is excellent at transporting the generated electrons. Specifically, the electron transport materials (metal complexes, heteroaromatic compounds, etc.) used in the electron transport layer (114, 114a, 114b) described above can be used. The electron donor may be any substance that exhibits electron donating properties to the organic compound. Specifically, alkali metals, alkaline earth metals, and rare earth metals are preferred, such as lithium, cesium, magnesium, calcium, erbium, and ytterbium. Alkali metal oxides and alkaline earth metal oxides are preferred, such as lithium oxide, calcium oxide, and barium oxide. Lewis bases such as magnesium oxide can also be used. Organic compounds such as tetrathiafulvalene (TTF) can also be used. Furthermore, a plurality of these materials may be laminated.

[0247] Alternatively, the electron injection layer (115, 115a, 115b) may be made of a mixed material containing an organic compound and a metal. The organic compound used here preferably has a LUMO level of -3.6 eV or more and -2.3 eV or less. A material having an unshared electron pair is also preferred.

[0248] Therefore, the organic compound used in the mixed material may be a mixed material obtained by mixing a heteroaromatic compound with a metal, as described above as being usable in the electron transport layer. Preferred heteroaromatic compounds include those having a five-membered ring structure (such as an imidazole ring, a triazole ring, an oxazole ring, an oxadiazole ring, a thiazole ring, or a benzimidazole ring), a six-membered ring structure (such as a pyridine ring, a diazine ring (including a pyrimidine ring, a pyrazine ring, or a pyridazine ring), a triazine ring, a bipyridine ring, or a terpyridine ring), or a fused ring structure partially including a six-membered ring structure (such as a quinoline ring, a benzoquinoline ring, a quinoxaline ring, a dibenzoquinoxaline ring, or a phenanthroline ring). Specific materials are described above, so further explanation is omitted here.

[0249] Furthermore, as the metal used in the above mixed material, it is preferable to use a transition metal belonging to Group 5, Group 7, Group 9 or Group 11 in the periodic table, and a material belonging to Group 13, such as Ag, Cu, Al or In. In this case, the organic compound forms a Singly Occupied Molecular Orbital (SOMO) with the transition metal.

[0250] For example, when light obtained from the light-emitting layer 113b is to be amplified, the optical distance between the second electrode 102 and the light-emitting layer 113b is preferably set to be less than ¼ of the wavelength λ of the light emitted by the light-emitting layer 113b. In this case, the optical distance can be adjusted by changing the film thickness of the electron-transporting layer 114b or the electron-injecting layer 115b.

[0251] Furthermore, as in the light-emitting device shown in Figure 2(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 formed.

[0252] <Charge generation layer> The charge generation layer 106 has a function of injecting electrons into the EL layer 103a and injecting 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 by adding an electron acceptor to a hole transporting material, or by adding an electron donor to an electron transporting material. Alternatively, both of these configurations may be stacked. By forming the charge generation layer 106 using the above-mentioned materials, it is possible to suppress an increase in driving voltage when EL layers are stacked.

[0253] When the charge generation layer 106 has a structure in which an electron acceptor is added to a hole-transporting material that is an organic compound, the material described in this embodiment can be used as the hole-transporting material. Examples of the electron acceptor include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ) and chloranil. Examples of the electron acceptor include oxides of metals that belong to Groups 4 to 8 of the periodic table. Specific examples include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide.

[0254] When the charge generation layer 106 has a structure in which an electron donor is added to an electron transporting material, the materials described in this embodiment can be used as the electron transporting material. As the electron donor, an alkali metal, an alkaline earth metal, a rare earth metal, or a metal belonging to Group 2 or Group 13 of the periodic table, or an oxide or carbonate thereof can be used. Specifically, lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium oxide, cesium carbonate, or the like can be preferably used. Alternatively, an organic compound such as tetrathianaphthacene can be used as the electron donor.

[0255] Although FIG. 2D shows a structure in which the EL layer 103 has two stacked layers, a stacked structure of three or more EL layers may be used by providing a charge generating layer between different EL layers.

[0256] <Substrate> The light-emitting device described in this embodiment mode can be formed on various substrates. Note that the type of substrate is not limited to a specific one. Examples of the substrate include a semiconductor substrate (for example, a single crystal substrate or a silicon substrate), an SOI substrate, a glass substrate, a quartz substrate, a plastic substrate, a metal substrate, a stainless steel substrate, a substrate having stainless steel foil, a tungsten substrate, a substrate having tungsten foil, a flexible substrate, a laminated film, paper containing a fibrous material, or a base film.

[0257] Examples of glass substrates include barium borosilicate glass, aluminoborosilicate glass, soda lime glass, etc. Examples of flexible substrates, laminated films, base films, etc. include plastics such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyethersulfone (PES), synthetic resins such as acrylic resins, polypropylene, polyester, polyvinyl fluoride, polyvinyl chloride, polyamide, polyimide, aramid, epoxy resins, inorganic vapor deposition films, and papers.

[0258] The light-emitting device described in this embodiment can be fabricated using a gas-phase method such as vapor deposition, a spin coating method, or a liquid-phase method such as an inkjet method. When a vapor deposition method is used, physical vapor deposition (PVD) methods such as sputtering, ion plating, ion beam deposition, molecular beam deposition, and vacuum deposition, and chemical vapor deposition (CVD) methods can be used. In particular, the layers having various functions 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, and electron injection layer 115) can be formed by a vapor deposition method (vacuum deposition, etc.), a coating method (dip coating, die coating, bar coating, spin coating, spray coating, etc.), a printing method (inkjet printing, screen printing, offset printing, flexography, gravure printing, microcontact printing, etc.), or the like.

[0259] When applying the above-mentioned coating method, printing method, or other film formation method, it is possible to use high molecular weight compounds (oligomers, dendrimers, polymers, etc.), medium molecular weight compounds (compounds in the intermediate range between low molecular weight and high molecular weight: molecular weight of 400 to 4000), inorganic compounds (quantum dot materials, etc.), etc. As quantum dot materials, colloidal quantum dot materials, alloy-type quantum dot materials, core-shell type quantum dot materials, core-type quantum dot materials, etc. can be used.

[0260] The layers constituting the EL layer 103 of the light-emitting device described in this embodiment (hole injection layer 111, hole transport layer 112, light-emitting layer 113, electron transport layer 114, and electron injection layer 115) are not limited to the materials described in this embodiment, and other materials can be used in combination as long as they can fulfill the functions of each layer.

[0261] In this specification and the like, the terms "layer" and "film" can be used interchangeably as appropriate.

[0262] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0263] (Embodiment 3) In this embodiment, a light-receiving and light-emitting device 700 will be described to explain a specific configuration example and a manufacturing method example of a light-emitting device according to one embodiment of the present invention. Note that the light-receiving and light-emitting device 700 can be called a light-emitting device because it includes a light-emitting device, and can be called a light-receiving device because it includes a light-receiving device. Furthermore, since the light-receiving and light-emitting device 700 can be applied to a display portion of an electronic device or the like, it can also be called a display panel or a display device.

[0264] <Configuration example of light emitting and receiving device 700> The light-emitting and receiving device 700 shown in FIG. 3A includes a light-emitting device 550B, a light-emitting device 550G, a light-emitting device 550R, and a light-receiving device 550PS. The light-emitting device 550B, the light-emitting device 550G, the light-emitting device 550R, and the light-receiving device 550PS are formed on a functional layer 520 provided on a first substrate 510. The functional layer 520 includes circuits such as a driving circuit composed of multiple transistors, as well as wiring and the like that electrically connects these devices. These driving circuits are, for example, electrically connected to the light-emitting device 550B, the light-emitting device 550G, the light-emitting device 550R, and the light-receiving device 550PS, respectively, and can drive these devices. The light-emitting and receiving device 700 also includes an insulating layer 705 on the functional layer 520 and each device (the light-emitting device and the light-receiving device). The insulating layer 705 functions to bond the second substrate 770 and the functional layer 520 together.

[0265] Note that light-emitting device 550B, light-emitting device 550G, and light-emitting device 550R have the device structure described in Embodiment 1, and light-receiving device 550PS has the device structure described later in Embodiment 8. Note that, although this embodiment describes a case where each device (plurality of light-emitting devices and light-receiving devices) can be formed separately, one embodiment of the present invention is not limited thereto.

[0266] In this specification and the like, a structure in which the light-emitting layers of the light-emitting devices of each color (e.g., blue (B), green (G), and red (R)) and the light-receiving layers of the light-receiving devices are separately fabricated or separately painted may be referred to as an SBS (Side By Side) structure. In the light-emitting and receiving device 700 shown in FIG. 3A, the light-emitting device 550B, the light-emitting device 550G, the light-emitting device 550R, and the light-receiving device 550PS are arranged in this order, but one embodiment of the present invention is not limited to this configuration. For example, in the light-emitting and receiving device 700, these devices may be arranged in the order of the light-emitting device 550R, the light-emitting device 550G, the light-emitting device 550B, and the light-receiving device 550PS.

[0267] In FIG. 3A, light-emitting device 550B has electrode 551B, electrode 552, and EL layer 103B. Light-emitting device 550G has electrode 551G, electrode 552, and EL layer 103G. Light-emitting device 550R has electrode 551R, electrode 552, and EL layer 103R. Light-receiving device 550PS has electrode 551PS, electrode 552, and light-receiving layer 103PS. Specific structures of the layers in the light-receiving device are as described in Embodiment 8. Specific structures of the layers in the light-emitting device are as described in Embodiment 2. EL layer 103B, EL layer 103G, and EL layer 103R have a stacked structure consisting of multiple layers with different functions, including light-emitting layers (105B, 105G, and 105R). Light-receiving layer 103PS has a stacked structure consisting of multiple layers with different functions, including active layer 105PS. 3(A) illustrates the case where the EL layer 103B has a hole injection / transport layer 104B, a light-emitting layer 105B, an electron transport layer 108B, and an electron injection layer 109; the EL layer 103G has a hole injection / transport layer 104G, a light-emitting layer 105G, an electron transport layer 108G, and an electron injection layer 109; the EL layer 103R has a hole injection / transport layer 104R, a light-emitting layer 105R, an electron transport layer 108R, and an electron injection layer 109; and the light-receiving layer 103PS has a first transport layer 104PS, an active layer 105PS, a second transport layer 108PS, and an electron injection layer 109; however, the present invention is not limited to this. The hole injection / transport layers (104B, 104G, 104R) are layers having the functions of the hole injection layer and the hole transport layer shown in the second embodiment, and may have a laminated structure.

[0268] The electron transport layers (108B, 108G, 108R) and the second transport layer 108PS may have a function of blocking holes that move from the anode side through the EL layers (103B, 103G, 103R) and the light-receiving layer 103PS to the cathode side. The electron injection layer 109 may have a laminated structure formed of partially or entirely different materials.

[0269] 3(A), an insulating layer 107 may be formed on the side surfaces (or edges) of the hole injection / transport layers (104B, 104G, 104R), the light-emitting layers (105B, 105G, 105R), and the electron transport layers (108B, 108G, 108R) of the EL layers (103B, 103G, 103R) and on the side surfaces (or edges) of the first transport layer 104PS, the active layer 105PS, and the second transport layer 108PS of the light-receiving layer 103PS. The insulating layer 107 is formed in contact with the side surfaces (or edges) of the EL layers (103B, 103G, 103R) and the light-receiving layer 103PS. This prevents oxygen, moisture, or their constituent elements from penetrating into the EL layers (103B, 103G, 103R) and the light-receiving layer 103PS from their side surfaces. The insulating layer 107 can be made of, for example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, or silicon nitride oxide. The insulating layer 107 may be formed by laminating the above-mentioned materials. The insulating layer 107 can be formed by sputtering, CVD, MBE, PLD, ALD, or other methods, but ALD is preferred because of its excellent coverage. The insulating layer 107 has a structure that continuously covers the side surfaces (or ends) of parts of the EL layers (103B, 103G, 103R) of adjacent light-emitting devices or parts of the light-receiving layer 103PS of a light-receiving device. 3(A), part of the EL layer 103B of the light-emitting device 550B and part of the EL layer 103G of the light-emitting device 550G have their side surfaces covered with the insulating layer 107. In addition, a partition wall 528 made of an insulating material may be formed in the region covered with the insulating layer 107, as shown in FIG.

[0270] An electron injection layer 109 is formed on the electron transport layers (108B, 108G, 108R) that are part of the EL layers (103B, 103G, 103R), the second transport layer 108PS that is part of the light-receiving layer 103PS, and the insulating layer 107. The electron injection layer 109 may have a stacked structure of two or more layers (for example, a stack of layers with different electrical resistances).

[0271] Furthermore, electrode 552 is formed on electron injection layer 109. Note that the electrodes (551B, 551G, 551R) and electrode 552 have overlapping regions. Furthermore, light-emitting layer 105B is provided between electrode 551B and electrode 552, light-emitting layer 105G is provided between electrode 551G and electrode 552, light-emitting layer 105R is provided between electrode 551R and electrode 552, and light-receiving layer 103PS is provided between electrode 551PS and electrode 552.

[0272] 3(A) (103B, 103G, 103R) have the same configuration as the EL layer 103 described in Embodiments 1 and 2. For example, the light-emitting layer 105B can emit blue light, the light-emitting layer 105G can emit green light, and the light-emitting layer 105R can emit red light.

[0273] A partition wall 528 is provided in a region surrounded by the electron injection layer 109 and the insulating layer 107. As shown in Fig. 3(A), the electrodes (551B, 551G, 551R, 551PS) of each light-emitting device, parts of the EL layers (103B, 103G, 103R), and parts of the light-receiving layer 103PS are in contact with the partition wall 528 at their sides (or ends) via the insulating layer 107.

[0274] In each EL layer and light-receiving layer, the hole injection layer included in the hole transport region located between the anode and the light-emitting layer, and between the anode and the active layer, often has high conductivity, and therefore, if it is formed as a layer common to adjacent devices, it may cause crosstalk. Therefore, by providing a partition wall 528 made of an insulating material between each EL layer and light-receiving layer as shown in this configuration example, it is possible to suppress the occurrence of crosstalk between adjacent devices.

[0275] Furthermore, in the manufacturing method described in this embodiment, the side surfaces (or edges) of the EL layer and the light-receiving layer are exposed during the patterning process. Therefore, the EL layer and the light-receiving layer are likely to deteriorate due to the intrusion of oxygen, water, and the like from the side surfaces (or edges) of the EL layer and the light-receiving layer. Therefore, by providing the partition 528, it is possible to suppress the deterioration of the EL layer and the light-receiving layer during the manufacturing process.

[0276] Furthermore, by providing the partition wall 528, it is possible to flatten the recess formed between adjacent devices. Flattening the recess can prevent disconnection of the electrodes 552 formed on each EL layer and light-receiving layer. Examples of insulating materials used to form the partition wall 528 include organic materials such as acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimideamide resin, silicone resin, siloxane resin, benzocyclobutene-based resin, phenolic resin, and precursors of these resins. Organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, and alcohol-soluble polyamide resin may also be used. Photosensitive resins such as photoresists can also be used. The photosensitive resin can be a positive-type material or a negative-type material.

[0277] By using a photosensitive resin, the partition wall 528 can be formed only by exposure and development processes. Alternatively, the partition wall 528 may be formed using a negative photosensitive resin (e.g., a resist material). When an insulating layer containing an organic material is used as the partition wall 528, it is preferable to use a material that absorbs visible light. If a material that absorbs visible light is used for the partition wall 528, the partition wall 528 can absorb light emitted from the EL layer, thereby suppressing light (stray light) that may leak into the adjacent EL layer and light-receiving layer. Therefore, a display panel with high display quality can be provided.

[0278] The difference in height between the upper surface of the partition wall 528 and the upper surface of any one of the EL layer 103B, the EL layer 103G, the EL layer 103R, and the light-receiving layer 103PS is, for example, preferably 0.5 times or less, more preferably 0.3 times or less, the thickness of the partition wall 528. For example, the partition wall 528 may be provided so that the upper surface of any one of the EL layer 103B, the EL layer 103G, the EL layer 103R, and the light-receiving layer 103PS is higher than the upper surface of the partition wall 528. For example, the partition wall 528 may be provided so that the upper surface of the partition wall 528 is higher than the upper surfaces of the EL layer 103B, the EL layer 103G, the EL layer 103R, and the light-receiving layer 103PS.

[0279] In a high-resolution light-receiving and light-emitting device (display panel) exceeding 1000 ppi, if electrical conduction is found between the EL layer 103B, the EL layer 103G, the EL layer 103R, and the light-receiving layer 103PS, crosstalk occurs, narrowing the color gamut that can be displayed by the light-receiving and light-emitting device. By providing the partition 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 that can display vivid colors can be provided.

[0280] 3(B) and 3(C) are schematic top views of the light emitting and receiving device 700 corresponding to the dashed line Ya-Yb in the cross-sectional view of FIG. 3(A). Specifically, the light emitting devices 550B, 550G, and 550R are arranged in a matrix. FIG. 3(B) shows a stripe arrangement in which light emitting devices of the same color are arranged in the X direction. FIG. 3(C) shows a configuration in which light emitting devices of the same color are arranged in the X direction, but with a pattern formed for each pixel. The arrangement of the light emitting devices is not limited to this; other arrangements, such as a delta arrangement or a zigzag arrangement, or a pentile arrangement or a diamond arrangement, may also be used.

[0281] In addition, since pattern formation is performed by photolithography in the separation processing of each EL layer (103B, 103G, 103R) and the light receiving layer 103PS, a high-definition light receiving / emitting device (display panel) can be produced. Furthermore, the side surfaces (edges) of each layer of the EL layer processed by pattern formation by photolithography have a shape that has approximately the same surface (or is located on approximately the same plane). Furthermore, the side surfaces (edges) of each layer of the light receiving layer processed by pattern formation by photolithography have a shape that has approximately the same surface (or is located on approximately the same plane). In this case, the width (SE) of the gap 580 between each EL layer and the light receiving layer is preferably 5 μm or less, and more preferably 1 μm or less.

[0282] In the EL layer, the hole injection layer included in the hole transport region located between the anode and the light-emitting layer, in particular, often has high conductivity, and therefore, if it is formed as a layer common to adjacent light-emitting devices, it may cause crosstalk. Therefore, by separating the EL layer by pattern formation using photolithography as shown in this configuration example, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0283] 3(D) is a schematic cross-sectional view corresponding to dashed line C1-C2 in FIG. 3(B) and FIG. 3(C). FIG. 3(D) shows connection portion 130 where connection electrode 551C and electrode 552 are electrically connected. In connection portion 130, electrode 552 is provided in contact with connection electrode 551C. In addition, partition wall 528 is provided to cover the end of connection electrode 551C.

[0284] <Example of manufacturing method of light emitting and receiving device> 4A, an electrode 551B, an electrode 551G, an electrode 551R, and an electrode 551PS are formed. For example, a conductive film is formed on the functional layer 520 formed on the first substrate 510, and is processed into a predetermined shape by photolithography.

[0285] Conductive films can be formed using methods such as sputtering, chemical vapor deposition (CVD), molecular beam epitaxy (MBE), vacuum evaporation, pulsed laser deposition (PLD), and atomic layer deposition (ALD). CVD methods include plasma enhanced chemical vapor deposition (PECVD) and thermal CVD. Metal organic chemical vapor deposition (MOCVD) is another type of thermal CVD.

[0286] In addition to the photolithography method described above, the conductive film may be processed by a nanoimprint method, a sandblasting method, a lift-off method, etc. Alternatively, an island-shaped thin film may be directly formed by a film formation method using a shielding mask such as a metal mask.

[0287] There are two typical photolithography methods. One is to form a resist mask on a thin film to be processed, process the thin film by etching or the like, and then remove the resist mask. The other is to form a photosensitive thin film, and then process the thin film into a desired shape by exposing and developing it. Note that the former method includes heat treatment steps such as baking after resist application (PAB: Pre Applied Bake) and baking after exposure (PEB: Post Exposure Bake). In one embodiment 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 partially containing organic compounds) used to form EL layers.

[0288] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these. Other light sources that can be used include ultraviolet light, KrF laser light, and ArF laser light. Exposure can also be performed using immersion exposure technology. Extreme ultraviolet (EUV) light or X-rays can also be used as the light used for exposure. Instead of light used for exposure, an electron beam can also be used. Extreme ultraviolet light, X-rays, or an electron beam are preferred because they enable extremely fine processing. When exposure is performed by scanning a beam such as an electron beam, a photomask is not required.

[0289] For etching the thin film using a resist mask, dry etching, wet etching, sandblasting, or the like can be used.

[0290] Next, as shown in FIG. 4(B), a hole injection / transport layer 104B, a light-emitting layer 105B, and an electron transport layer 108B are formed on the electrodes 551B, 551G, 551R, and 551PS. The hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B can be formed by, for example, vacuum deposition. Furthermore, a sacrificial layer 110B is formed on the electron transport layer 108B. The materials described in Embodiment 2 can be used to form the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B.

[0291] The sacrificial layer 110B is preferably a film that is highly resistant to the etching processes of the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B, i.e., a film with a large etching selectivity. The sacrificial layer 110B preferably has a stacked structure of a first sacrificial layer and a second sacrificial layer that have different etching selectivity. The sacrificial layer 110B can be a film that can be removed by wet etching, which causes minimal damage to the EL layer 103B. Oxalic acid or the like can be used as an etching material for wet etching.

[0292] The sacrificial layer 110B may be, for example, a metal film, an alloy film, a metal oxide film, a semiconductor film, an inorganic insulating film, etc. The sacrificial layer 110B may be formed by various film formation methods such as a sputtering method, a vapor deposition method, a CVD method, an ALD method, etc.

[0293] The sacrificial layer 110B may be made of a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, or tantalum, or an alloy material containing such a metal material. In particular, it is preferable to use a low-melting-point material such as aluminum or silver.

[0294] The sacrificial layer 110B may be made of a metal oxide such as indium gallium zinc oxide (In-Ga-Zn oxide, also referred to as IGZO). Other examples include indium oxide, indium zinc oxide (In-Zn oxide), indium tin oxide (In-Sn oxide), indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), and indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide). Alternatively, silicon-containing indium tin oxide may be used.

[0295] The present invention can also be applied to a case where, instead of the gallium, an element M (wherein M is one or more elements selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) is used. In particular, it is preferable that M is one or more elements selected from gallium, aluminum, and yttrium.

[0296] The sacrificial layer 110B may be made of an inorganic insulating material such as aluminum oxide, hafnium oxide, or silicon oxide.

[0297] Furthermore, it is preferable to use a material for the sacrificial layer 110B that is soluble in a chemically stable solvent, as compared with the electron transport layer 108B located at the top. Materials that dissolve in water or alcohol are particularly suitable for use in the sacrificial layer 110B. When forming the sacrificial layer 110B, it is preferable to apply the sacrificial layer 110B dissolved in a solvent such as water or alcohol using a wet film-forming method, and then perform a heat treatment to evaporate the solvent. In this case, performing the heat treatment under a reduced pressure atmosphere is preferable because it allows the solvent to be removed at a low temperature and in a short time, thereby reducing thermal damage to the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B.

[0298] When the sacrificial layer 110B has a laminated structure, a layer made of the above-mentioned material can be used as a first sacrificial layer, and a second sacrificial layer can be formed thereon to form a laminated structure.

[0299] 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 when the second sacrificial layer is processed. Therefore, a combination of films with a high etching selectivity is selected for the first sacrificial layer and the second sacrificial layer. Therefore, a film that can be used for the second sacrificial layer can be selected depending on the etching conditions for the first sacrificial layer and the second sacrificial layer.

[0300] For example, when dry etching using a gas containing fluorine (also called a fluorine-based gas) is used to etch the second sacrificial layer, silicon, silicon nitride, silicon oxide, tungsten, titanium, molybdenum, tantalum, tantalum nitride, an alloy containing molybdenum and niobium, or an alloy containing molybdenum and tungsten can be used for the second sacrificial layer.Here, metal oxide films such as IGZO and ITO can be used as films that can have a large etching selectivity (i.e., can slow the etching rate) compared to dry etching using the above fluorine-based gas, and these can be used for the first sacrificial layer.

[0301] However, the second sacrificial layer is not limited to this, and can be selected from various materials depending on the etching conditions of the first sacrificial layer and the second sacrificial layer, for example, from among the films that can be used for the first sacrificial layer.

[0302] The second sacrificial layer may be, for example, a nitride film, such as silicon nitride, aluminum nitride, hafnium nitride, titanium nitride, tantalum nitride, tungsten nitride, gallium nitride, or germanium nitride.

[0303] Alternatively, an oxide film can be used as the second sacrificial layer. Typically, an oxide film or an oxynitride film such as silicon oxide, silicon oxynitride, aluminum oxide, aluminum oxynitride, hafnium oxide, or hafnium oxynitride can be used.

[0304] Next, as shown in FIG. 4(C), resist is applied to the sacrificial layer 110B, and the resist is formed into a desired shape (resist mask: REG) using photolithography. When using this method, heat treatment processes such as pre-applied bake (PAB) after resist application and post-exposure bake (PEB) after exposure are also required. For example, the PAB temperature is approximately 100°C, and the PEB temperature is approximately 120°C. Therefore, the light-emitting device must be able to withstand these processing temperatures.

[0305] Next, using the 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 hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B not covered by the sacrificial layer 110B is removed by etching, thereby processing the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B into a shape having a side surface on the electrode 551B (or an exposed side surface) or into a strip shape extending in a direction intersecting the paper. Dry etching is preferred for this etching. When the sacrificial layer 110B has a stacked structure of the first and second sacrificial layers, a portion of the second sacrificial layer may be etched using the resist mask REG, and then the resist mask REG may be removed. Then, a portion of the first sacrificial layer may be etched using the second sacrificial layer as a mask, thereby processing the hole injection / transport layer 104B, the light-emitting layer 105B, and the electron transport layer 108B into the desired shapes. These etching processes result in the shape shown in FIG. 5(A).

[0306] 5(B), a hole injection / transport layer 104G, a light-emitting layer 105G, and an electron transport layer 108G are formed on the sacrificial layer 110B, the electrode 551G, the electrode 551R, and the electrode 551PS. The materials used to form the hole injection / transport layer 104G, the light-emitting layer 105G, and the electron transport layer 108G can be the same as those used in Embodiment 2. The hole injection / transport layer 104G, the light-emitting layer 105G, and the electron transport layer 108G can be formed by vacuum deposition, for example.

[0307] 5(C), a sacrificial layer 110G is formed on the electron transport layer 108G, a resist is applied to the sacrificial layer 110G, and the resist is formed into a desired shape (resist mask: REG) using photolithography. The portion of the sacrificial layer 110G that is not covered by the resist mask REG is removed by etching. After the resist mask REG is removed, the portions of the hole injection / transport layer 104G, the light-emitting layer 105G, and the electron transport layer 108G that are not covered by the sacrificial layer 110G are removed by etching. The hole injection / transport layer 104G, the light-emitting layer 105G, and the electron transport layer 108G are then etched away to form a shape that has a side surface on the electrode 551G (or has an exposed side surface) or a strip-like shape extending in a direction intersecting the plane of the page. Dry etching is preferred for this etching. Furthermore, the sacrificial layer 110G can be made of the same material as the sacrificial layer 110B. When the sacrificial layer 110G has a laminated structure of the first and second sacrificial layers, the second sacrificial layer may be partially etched using a resist mask REG, and then the resist mask REG may be removed. Then, the first sacrificial layer may be partially etched using the second sacrificial layer as a mask, thereby processing the hole injection / transport layer 104G, the light-emitting layer 105G, and the electron transport layer 108G into the desired shapes. These etching processes result in the shape shown in FIG. 6(A).

[0308] 6(B), the hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R are formed on the sacrificial layer 110B, the sacrificial layer 110G, the electrode 551R, and the electrode 551PS. The materials used to form the hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R can be the same as those used in Embodiment 2. The hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R can be formed by vacuum deposition, for example.

[0309] 6(C), a sacrificial layer 110R is formed on the electron transport layer 108R, a resist is applied to the sacrificial layer 110R, and the resist is formed into a desired shape (resist mask: REG) using photolithography. The portion of the sacrificial layer 110R that is not covered by the resulting resist mask REG is removed by etching. After the resist mask REG is removed, the portions of the hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R that are not covered by the sacrificial layer 110R are removed by etching to process the hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R into a shape that has a side surface on the electrode 551R (or whose side surface is exposed) or into a strip shape extending in a direction intersecting the plane of the page. Dry etching is preferred as the etching method. Furthermore, the sacrificial layer 110R can be made of the same material as the sacrificial layer 110B. When the sacrificial layer 110R has a laminated structure of the first and second sacrificial layers, the second sacrificial layer may be partially etched using a resist mask REG, and then the resist mask REG may be removed. Then, the first sacrificial layer may be partially etched using the second sacrificial layer as a mask, thereby processing the hole injection / transport layer 104R, the light-emitting layer 105R, and the electron transport layer 108R into the desired shapes. These etching processes result in the shape shown in FIG. 7(A).

[0310] 7(B), the first transport layer 104PS, the active layer 105PS, and the second transport layer 108PS are formed on the sacrificial layers 110B, 110G, 110R, and the electrode 551PS. The materials used to form the first transport layer 104PS, the active layer 105PS, and the second transport layer 108PS can be the same as those described in Embodiment 1. The first transport layer 104PS, the active layer 105PS, and the second transport layer 108PS can be formed by vacuum deposition, for example.

[0311] 7(C), a sacrificial layer 110PS is formed on the second transport layer 108PS, a resist is applied to the sacrificial layer 110PS, and the resist is formed into a desired shape (resist mask: REG) using photolithography. The portion of the sacrificial layer 110PS that is not covered by the resulting resist mask REG is removed by etching. After the resist mask REG is removed, the portions of the first transport layer 104PS, the active layer 105PS, and the second transport layer 108PS that are not covered by the sacrificial layer 110PS are removed by etching, and the first transport layer 104PS, the active layer 105PS, and the second transport layer 108PS are processed into a shape having a side surface on the electrode 551PS (or an exposed side surface) or into a strip-like shape extending in a direction intersecting with the paper surface. Note that dry etching is preferred for the etching. Furthermore, the sacrificial layer 110PS can be made of the same material as the sacrificial layer 110B. When the sacrificial layer 110PS has a laminated structure of the first and second sacrificial layers, a portion of the second sacrificial layer may be etched using a resist mask REG, and then the resist mask REG may be removed. Then, a portion of the first sacrificial layer may be etched using the second sacrificial layer as a mask, thereby processing the first transport layer 104PS, the active layer 105PS, and the second transport layer 108PS into the predetermined shapes. These etching processes result in the shape shown in FIG. 7(D).

[0312] Next, as shown in FIG. 8(A), the insulating layer 107 is formed on the sacrificial layers 110B, 110G, 110R, and 110PS.

[0313] The insulating layer 107 can be formed by, for example, ALD. In this case, the insulating layer 107 is formed in contact with the side surfaces (ends) of the hole injection / transport layers (104B, 104G, 104R), light-emitting layers (105B, 105G, 105R), and electron transport layers (108B, 108G, 108R) of the light-emitting devices, as well as the first transport layer 104PS, active layer 105PS, and second transport layer 108PS of the light-receiving device, as shown in FIG. 8(A). This prevents oxygen, moisture, or their constituent elements from penetrating into the interior from the side surfaces. Examples of materials that can be used for the insulating layer 107 include aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, and silicon nitride oxide.

[0314] 8(B), after removing part of the insulating layer 107 and the sacrificial layers (110B, 110G, 110R, and 110PS), the electron injection layer 109 is formed over the insulating layer 107, the electron transport layers (108B, 108G, and 108R), and the second transport layer 108PS. The electron injection layer 109 can be formed using the materials described in Embodiment 2. Note that the electron injection layer 109 is formed by, for example, vacuum evaporation. The electron injection layer 109 is structured to contact, via the insulating layer 107, the hole injection / transport layers (104B, 104G, 104R), the light-emitting layers (105B, 105G, 105R), and the electron transport layers (108B, 108G, 108R) of the light-emitting devices, as well as the first transport layer 104PS, the active layer 105PS, and the second transport layer 108PS of the light-receiving device on their respective side surfaces (ends).

[0315] 8(C), an electrode 552 is formed. The electrode 552 is formed by, for example, vacuum deposition. The electrode 552 is formed on the electron injection layer 109. The electrode 552 is structured to be in contact with the hole injection / transport layers (104B, 104G, 104R), light-emitting layers (105B, 105G, 105R), and electron transport layers (108B, 108G, 108R) of the light-emitting devices, and with the side surfaces (ends) of the first transport layer 104PS, active layer 105PS, and second transport layer 108PS of the light-receiving device, via the electron injection layer 109 and the insulating layer 107. This prevents electrical short-circuiting between the hole injection / transport layers (104B, 104G, 104R), the light-emitting layers (105B, 105G, 105R), and the electron transport layers (108B, 108G, 108R) of each light-emitting device, and between the first transport layer 104PS, the active layer 105PS, and the second transport layer 108PS of the light-receiving device and the electrode 552.

[0316] Through the above steps, EL layers 103B, 103G, 103R, and light-receiving layers 103PS in light-emitting devices 550B, 550G, and 550R, and light-receiving devices 550PS can be separated and processed, respectively.

[0317] In addition, since pattern formation is performed by photolithography in the separation processing of these EL layers (103B, 103G, 103R) and the light receiving layer 103PS, a high-definition light receiving / emitting device (display panel) can be produced. Furthermore, the side surfaces (edges) of each layer of the EL layer processed by pattern formation by photolithography have a shape that has approximately the same surface (or is located on approximately the same plane). Furthermore, the side surfaces (edges) of each layer of the light receiving layer processed by pattern formation by photolithography have a shape that has approximately the same surface (or is located on approximately the same plane).

[0318] Furthermore, the hole injection / transport layers (104B, 104G, 104R) in these EL layers and the first transport layer 104PS in the light-receiving layer often have high electrical conductivity, which can cause crosstalk if they are formed as a common layer between adjacent devices. Therefore, by separating each layer through pattern formation using photolithography, as shown in this configuration example, it is possible to suppress the occurrence of crosstalk between adjacent devices.

[0319] In this configuration, the hole injection / transport layers (104B, 104G, 104R), light-emitting layers (105B, 105G, 105R), and electron transport layers (108B, 108G, 108R) included in each EL layer (103B, 103G, and 103R) of each light-emitting device, and the first transport layer 104PS, active layer 105PS, and second transport layer 108PS included in the light-receiving layer 103PS of the light-receiving device are patterned by photolithography during separation processing. Therefore, the side surfaces (edges) of the processed EL layers have roughly the same surface (or are located on roughly the same plane). Furthermore, the side surfaces (edges) of the light-receiving layers processed by patterning by photolithography have roughly the same surface (or are located on roughly the same plane).

[0320] Furthermore, the hole injection / transport layers (104B, 104G, 104R), light-emitting layers (105B, 105G, 105R), and electron transport layers (108B, 108G, 108R) included in each EL layer (103B, 103G, 103R) of each light-emitting device, and the first transport layer 104PS, active layer 105PS, and second transport layer 108PS included in the absorption layer 103PS of the light-receiving device are patterned by photolithography during separation processing, so that each processed side (edge) has a gap 580 between adjacent devices. Note that in Figure 8(C), when the gap 580 is represented by SE, which is the distance between the EL layer or absorption layer of adjacent devices, the smaller the distance SE, the higher the aperture ratio and the resolution. On the other hand, the greater the distance SE, the more tolerant the influence of manufacturing process variations between adjacent light-emitting devices can be, and therefore the higher the manufacturing yield can be. Because the light-emitting devices and light-receiving devices manufactured according to the present specification are suitable for miniaturization processes, the distance SE between the EL layers or absorption layers of adjacent devices can be set to 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 (e.g., 1.5 μm or thereabouts).

[0321] In this specification etc., a device fabricated using a metal mask or an FMM (fine metal mask, high-resolution metal mask) may be referred to as a device with an MM (metal mask) structure. In addition, in this specification etc., a device fabricated without using a metal mask or an FMM may be referred to as a device with an MML (metal maskless) structure. Because an MML structure light emitting and receiving device is fabricated without using a metal mask, it has a higher degree of design freedom in terms of pixel arrangement, pixel shape, etc. than an FMM structure or MM structure light emitting and receiving device.

[0322] The island-shaped EL layer in an MML-structure light-emitting / receiving device is not formed using a metal mask pattern, but is formed by processing the EL layer after it has been deposited. This makes it possible to realize light-emitting / receiving devices with higher resolution or a higher aperture ratio than ever before. Furthermore, since the EL layer can be made differently for each color, it is possible to realize light-emitting / receiving devices with extremely vivid images, high contrast, and high display quality. Furthermore, by providing a sacrificial layer on the EL layer, damage to the EL layer during the manufacturing process can be reduced, thereby improving the reliability of the light-emitting device.

[0323] In the light-emitting device 550B, the light-emitting device 550G, and the light-emitting device 550R shown in Figures 3(A) and 8(C), the width of the EL layer (103B, 103G, 103R) is approximately equal to the width of the electrode (551B, 551G, 551R), and in the light-receiving device 550PS, the width of the light-receiving layer 103PS is approximately equal to the width of the electrode 551PS, but one embodiment of the present invention is not limited to this.

[0324] In light-emitting devices 550B, 550G, and 550R, the width of the EL layers (103B, 103G, and 103R) may be smaller than the width of the electrodes (551B, 551G, and 551R). In light-receiving device 550PS, the width of light-receiving layer 103PS may be smaller than the width of electrode 551PS. Figure 8(D) shows an example in which the width of the EL layers (103B and 103G) is smaller than the width of the electrodes (551B and 551G) in light-emitting device 550B and light-emitting device 550G.

[0325] In light-emitting devices 550B, 550G, and 550R, the width of the EL layers (103B, 103G, and 103R) may be greater than the width of the electrodes (551B, 551G, and 551R). In light-receiving device 550PS, the width of light-receiving layer 103PS may be greater than the width of electrode 551PS. Figure 8(E) shows an example in which the width of EL layer 103R is greater than the width of electrode 551R in light-emitting device 550R.

[0326] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0327] (Fourth embodiment) In this embodiment, the device 720 will be described with reference to FIGS. 9 to 11. The device 720 shown in FIGS. 9 to 11 is a light-emitting device because it includes the light-emitting device described in Embodiments 1 and 2. However, since the device 720 can be applied to display units of electronic devices, it can also be called a display panel or a display device. Furthermore, when the device is configured to use the light-emitting device as a light source and include a light-receiving device that can receive light from the light-emitting device, it can also be called a light-receiving / emitting device. These light-emitting devices, display panels, display devices, and light-receiving / emitting devices are configured to include at least a light-emitting device.

[0328] Furthermore, the light-emitting device, display panel, display device, and light-emitting and receiving device of the present embodiment can be a high-resolution or large-sized light-emitting device, display panel, display device, and light-emitting and receiving device. Therefore, the light-emitting device, display panel, display device, and light-emitting and receiving device of the present embodiment can be used in the display portion of electronic devices having relatively large screens, such as television devices, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, smartphones, wristwatch-type terminals, tablet terminals, personal digital assistants, and sound reproducing devices.

[0329] FIG. 9A shows a top view of a device (including a light-emitting device, a display panel, a display device, and a light-emitting and receiving device) 720.

[0330] 9(A), a device 720 has a structure in which a substrate 710 and a substrate 711 are bonded together. The device 720 also has a display region 701, a circuit 704, a wiring 706, and the like. Note that the display region 701 has a plurality of pixels, and a pixel 703(i,j) shown in FIG. 9(A) has a pixel 703(i+1,j) adjacent to the pixel 703(i,j) as shown in FIG. 9(B).

[0331] 9A, the device 720 has an example in which an IC (integrated circuit) 712 is provided on a substrate 710 by a chip-on-glass (COG) method, a chip-on-film (COF) method, or the like. Note that an IC having a scan line driver circuit or a signal line driver circuit, for example, can be used as the IC 712. In FIG. 9A, an IC having a signal line driver circuit is used as the IC 712, and a configuration having a scan line driver circuit is shown as the circuit 704.

[0332] The wiring 706 has a function of supplying signals and power to the display region 701 and the circuit 704. The signals and power are input to the wiring 706 from the outside via a flexible printed circuit (FPC) 713 or input to the wiring 706 from an IC 712. Note that the device 720 may not be provided with an IC. Alternatively, the IC may be mounted on the FPC by a COF method or the like.

[0333] FIG. 9B shows pixels 703(i,j) and 703(i+1,j) in the display region 701. That is, pixel 703(i,j) can be configured to have multiple subpixels having light-emitting devices that emit different colors. Alternatively, pixel 703(i,j) can be configured to include multiple subpixels having light-emitting devices that emit the same color. When a pixel has multiple subpixels having light-emitting devices that emit different colors, the pixel can be configured to have, for example, three types of subpixels. Examples of the three subpixels include red (R), green (G), and blue (B) subpixels, or yellow (Y), cyan (C), and magenta (M) subpixels. Alternatively, the pixel can be configured to have four types of subpixels. Examples of the four subpixels include R, G, B, and white (W) subpixels, or R, G, B, and Y subpixels. Specifically, the pixel 703(i,j) may be configured with a sub-pixel 702B(i,j) that displays blue, a sub-pixel 702G(i,j) that displays green, and a sub-pixel 702R(i,j) that displays red.

[0334] Additionally, device 720 includes subpixels with light-receiving devices as well as subpixels with light-emitting devices.

[0335] 9(C) to 9(E) show examples of various layouts including subpixels 702PS(i,j) having light-receiving devices. The pixel arrangement shown in FIG. 9(C) is a stripe arrangement, and the pixel arrangement shown in FIG. 9(D) is a matrix arrangement. The pixel arrangement shown in FIG. 9(E) has a configuration in which three subpixels (subpixels R, G, and PS) are vertically arranged next to one subpixel (subpixel B).

[0336] Furthermore, as shown in Figure 9(F), a subpixel 702IR(i,j) that emits infrared light may be added to the above set to form pixel 703(i,j). The pixel arrangement shown in Figure 9(F) has a configuration in which three vertically elongated subpixels G, B, and R are arranged horizontally, and below them, a subpixel PS and a horizontally elongated subpixel IR are arranged horizontally. Specifically, a subpixel 702IR(i,j) that emits light containing light having a wavelength of 650 nm or more and 1000 nm or less may be used for pixel 703(i,j). Although the wavelength of light detected by subpixel 702PS(i,j) is not particularly limited, it is preferable that the light-receiving device of subpixel 702PS(i,j) is sensitive to light emitted by the light-emitting device of subpixel 702R(i,j), subpixel 702G(i,j), subpixel 702B(i,j), or subpixel 702IR(i,j). For example, it is preferable to detect one or more of light in wavelength ranges such as blue, purple, blue-purple, green, yellow-green, yellow, orange, and red, and light in the infrared wavelength range.

[0337] The arrangement of the sub-pixels is not limited to the configurations shown in Figures 9(B) to 9(F), and various methods can be applied. Examples of the arrangement of the sub-pixels include a stripe arrangement, an S-stripe arrangement, a matrix arrangement, a delta arrangement, a Bayer arrangement, and a pentile arrangement.

[0338] Examples of the top surface shape of the sub-pixel include polygons such as triangles, quadrilaterals (including rectangles and squares), and pentagons, as well as polygons with rounded corners, ellipses, circles, etc. The top surface shape of the sub-pixels here corresponds to the top surface shape of the light-emitting region of the light-emitting device.

[0339] Furthermore, when a pixel has not only a light-emitting device but also a light-receiving device, the pixel has a light-receiving function, so that it is possible to detect contact or proximity of an object while displaying an image. For example, instead of displaying an image using all of the sub-pixels of the light-emitting device, some of the sub-pixels can emit light as a light source and the remaining sub-pixels can display an image.

[0340] It is preferable that the light-receiving area of ​​the subpixel 702PS(i,j) be smaller than the light-emitting area of ​​the other subpixels. The smaller the light-receiving area, the narrower the imaging range, which makes it possible to suppress blurring in the imaging result and improve resolution. Therefore, by using the subpixel 702PS(i,j), high-definition or high-resolution imaging can be performed. For example, the subpixel 702PS(i,j) can be used to capture images for personal authentication using fingerprints, palm prints, irises, pulse shapes (including vein shapes and artery shapes), faces, etc.

[0341] The subpixel 702PS(i,j) can be used as a touch sensor (also called a direct touch sensor) or a near-touch sensor (also called a hover sensor, hover touch sensor, non-contact sensor, or touchless sensor). For example, the subpixel 702PS(i,j) preferably detects infrared light, which enables touch detection even in dark places.

[0342] Here, a touch sensor or near-touch sensor can detect the proximity or contact of an object (such as a finger, hand, or pen). A touch sensor can detect an object when the light-emitting / receiving device and the object are in direct contact with each other. A near-touch sensor can detect an object even if the object does not come into contact with the light-emitting / receiving device. For example, a configuration is preferred in which the light-emitting / receiving device can detect an object when the distance between the light-emitting / receiving device and the object is between 0.1 mm and 300 mm, preferably between 3 mm and 50 mm. This configuration enables the light-emitting / receiving device to be operated without the object directly touching it, in other words, it enables the light-emitting / receiving device to be operated in a non-contact (touchless) manner. This configuration reduces the risk of the light-emitting / receiving device becoming dirty or scratched, or enables the object to operate the light-emitting / receiving device without directly touching dirt (e.g., dust, bacteria, or viruses) attached to the light-emitting / receiving device.

[0343] In order to capture high-resolution images, it is preferable that the sub-pixels 702PS(i,j) are provided in all pixels of the light-emitting and receiving device. On the other hand, when used in a touch sensor or near-touch sensor, the sub-pixels 702PS(i,j) do not require high accuracy compared to when capturing images of fingerprints, etc., so they may be provided in only some of the pixels of the light-emitting and receiving device. By making the number of sub-pixels 702PS(i,j) in the light-emitting and receiving device smaller than the number of sub-pixels 702R(i,j), etc., the detection speed can be increased.

[0344] Next, an example of a pixel circuit of a subpixel having a light-emitting device will be described with reference to FIG. 10A. The pixel circuit 530 shown in FIG. 10A includes a light-emitting device (EL) 550, a transistor M15, a transistor M16, a transistor M17, and a capacitor C3. A light-emitting diode can be used as the light-emitting device 550. In particular, it is preferable to use the light-emitting device described in Embodiments 1 and 2 as the light-emitting device 550.

[0345] 10A, the transistor M15 has a gate electrically connected to a wiring VG, one of its source and drain electrically connected to a wiring VS, and the other of its source and drain electrically connected to one electrode of a capacitor C3 and the gate of a transistor M16. One of its source and drain is electrically connected to a wiring V4, and the other is electrically connected to an anode of a light-emitting device 550 and one of a source and drain of a transistor M17. The transistor M17 has a gate electrically connected to a wiring MS, and the other of its source and drain is electrically connected to a wiring OUT2. The cathode of the light-emitting device 550 is electrically connected to a wiring V5.

[0346] A constant potential is supplied to the wiring V4 and the wiring V5. The anode side of the light-emitting device 550 can be set to a high potential, and the cathode side can be set to a lower potential than the anode side. The transistor M15 is controlled by a signal supplied to the wiring VG and functions as a selection transistor for controlling the selection state of the pixel circuit 530. The transistor M16 also functions as a drive transistor that controls the current flowing through the light-emitting device 550 depending on the potential supplied to its gate. When the transistor M15 is in a conductive state, the potential supplied to the wiring VS is supplied to the gate of the transistor M16, and the light emission brightness of the light-emitting device 550 can be controlled depending on the potential. The transistor M17 is controlled by a signal supplied to the wiring MS and has the function of outputting the potential between the transistor M16 and the light-emitting device 550 to the outside via the wiring OUT2.

[0347] Note that it is preferable to use transistors using a metal oxide (oxide semiconductor) for a semiconductor layer in which a channel is formed as the transistors M15, M16, and M17 included in the pixel circuit 530 of FIG. 10(A) and the transistors M11, M12, M13, and M14 included in the pixel circuit 531 of FIG. 10(B).

[0348] A transistor using a metal oxide, which has a wider band gap and a lower carrier density than silicon, can achieve an extremely small off-state current. Therefore, the small off-state current allows charge stored in a capacitor connected in series with the transistor to be held for a long period of time. Therefore, it is preferable to use a transistor including an oxide semiconductor for the transistor M11, the transistor M12, and the transistor M15, which are connected in series with the capacitor C2 or the capacitor C3. Furthermore, by using a transistor including an oxide semiconductor for other transistors as well, manufacturing costs can be reduced.

[0349] Alternatively, the transistors M11 to M17 may be transistors in which silicon is used as a semiconductor in which a channel is formed. In particular, using silicon with high crystallinity, such as single crystal silicon or polycrystalline silicon, is preferable because high field-effect mobility can be achieved and higher-speed operation is possible.

[0350] Alternatively, a structure may be used in which at least one of the transistors M11 to M17 includes an oxide semiconductor and the remaining transistors include silicon.

[0351] Next, an example of a pixel circuit of a sub-pixel having a light receiving device will be described with reference to Fig. 10(B). The pixel circuit 531 shown in Fig. 10(B) has a light receiving device (PD) 560, transistors M11, M12, M13, and M14, and a capacitor C2. Here, an example is shown in which a photodiode is used as the light receiving device (PD) 560.

[0352] 10B, the anode of the photo-receiving device (PD) 560 is electrically connected to the wiring V1, and the cathode is electrically connected to one of the source and drain of the transistor M11. The gate of the transistor M11 is electrically connected to the wiring TX, and the other of the source and drain is electrically connected to one electrode of the capacitor C2, one of the source and drain of the transistor M12, and the gate of the transistor M13. The gate of the transistor M12 is electrically connected to the wiring RES, and the other of the source and drain is electrically connected to the wiring V2. The source and drain of the transistor M13 is electrically connected to the wiring V3, and the other of the source and drain is electrically connected to one of the source and drain of the transistor M14. The gate of the transistor M14 is electrically connected to the wiring SE1, and the other of the source and drain is electrically connected to the wiring OUT1.

[0353] A constant potential is supplied to the wiring V1, wiring V2, and wiring V3. When the photodetector (PD) 560 is driven in reverse bias, a potential higher than the potential of the wiring V1 is supplied to the wiring V2. The transistor M12 is controlled by a signal supplied to the wiring RES and has a function of resetting the potential of a node connected to the gate of the transistor M13 to the potential supplied to the wiring V2. The transistor M11 is controlled by a signal supplied to the wiring TX and has a function of controlling the timing at which the potential of the node changes depending on the current flowing through the photodetector (PD) 560. The transistor M13 functions as an amplifying transistor that outputs a signal corresponding to the potential of the node. The transistor M14 is controlled by a signal supplied to the wiring SE1 and functions as a selection transistor that reads out an output corresponding to the potential of the node to an external circuit connected to the wiring OUT1.

[0354] Note that although the transistors are shown as n-channel transistors in FIGS. 10A and 10B, p-channel transistors can also be used.

[0355] The transistors included in the pixel circuit 530 and the transistors included in the pixel circuit 531 are preferably formed side by side on the same substrate. In particular, it is preferable to configure the transistors included in the pixel circuit 530 and the transistors included in the pixel circuit 531 to be mixed and periodically arranged in one region.

[0356] It is also preferable to provide one or more layers having one or both of a transistor and a capacitor element at a position overlapping the light receiving device (PD) 560 or the light emitting device (EL) 550. This reduces the effective area occupied by each pixel circuit, enabling a high-definition light receiving section or display section to be realized.

[0357] Next, an example of a specific structure of a transistor that can be applied to the pixel circuits described with reference to Figures 10A and 10B is shown in Figure 10C. Note that a bottom-gate transistor, a top-gate transistor, or the like can be used as the transistor as appropriate.

[0358] 10C includes 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 over, for example, an insulating film 501C. The transistor also includes an insulating film 516 (insulating films 516A and 516B) and an insulating film 518.

[0359] The semiconductor film 508 has a region 508A electrically connected to the conductive film 512A and a region 508B electrically connected to the conductive film 512B. The semiconductor film 508 has a region 508C between the region 508A and the region 508B.

[0360] The conductive film 504 has a region overlapping with the region 508C, and functions as a gate electrode.

[0361] 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.

[0362] The conductive film 512A has either a function as a source electrode or a function as a drain electrode, and the conductive film 512B has the other function as a source electrode or a drain electrode.

[0363] The conductive film 524 can also be used for a transistor. The conductive film 524 has a region where the semiconductor film 508 is sandwiched between the conductive film 524 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.

[0364] The insulating film 516 functions as, for example, a protective film that covers the semiconductor film 508. Specific examples of the insulating film 516 that can be used include a silicon oxide film, a silicon oxynitride film, a silicon nitride oxide film, a silicon nitride film, an aluminum oxide film, a hafnium oxide film, an yttrium oxide film, a zirconium oxide film, a gallium oxide film, a tantalum oxide film, a magnesium oxide film, a lanthanum oxide film, a cerium oxide film, and a neodymium oxide film.

[0365] The insulating film 518 is preferably formed using a material that has a function of suppressing diffusion of, for example, oxygen, hydrogen, water, alkali metals, alkaline earth metals, and the like. Specifically, for example, silicon nitride, silicon oxynitride, aluminum nitride, aluminum oxynitride, or the like can be used for the insulating film 518. Furthermore, the number of nitrogen atoms contained in silicon oxynitride and aluminum oxynitride is preferably larger than the number of oxygen atoms.

[0366] Note that a semiconductor film to be used for a transistor in a pixel circuit can be formed in the same process as a semiconductor film to be used for a transistor in a driver circuit. For example, a semiconductor film having the same composition as that of a semiconductor film to be used for a transistor in a pixel circuit can be used for the driver circuit.

[0367] The semiconductor film 508 preferably contains, for example, indium, M (wherein M is one or more elements selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, M is preferably one or more elements selected from aluminum, gallium, yttrium, and tin.

[0368] In particular, it is preferable to use an oxide containing indium (In), gallium (Ga), and zinc (Zn) (also referred to as IGZO) for the semiconductor film 508. Alternatively, it is preferable to use an oxide containing indium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium, gallium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium (In), aluminum (Al), and zinc (Zn) (also referred to as IAZO). Alternatively, it is preferable to use an oxide containing indium (In), aluminum (Al), gallium (Ga), and zinc (Zn) (also referred to as IAGZO).

[0369] When the semiconductor film is an In-M-Zn oxide, the atomic ratio of In in the In-M-Zn oxide is preferably equal to or greater than the atomic ratio of M. The atomic ratio of metal elements in such an In-M-Zn oxide may be In:M:Zn=1:1:1 or a composition in the vicinity thereof, In:M:Zn=1:1:1.2 or a composition in the vicinity thereof, In:M:Zn=1:3:2 or a composition in the vicinity thereof, In:M:Zn=1:3:4 or a composition in the vicinity thereof, In:M:Zn=2:1:3 or a composition in the vicinity thereof, In:M:Zn=3:1:2 or a composition in the vicinity thereof, or In:M:Zn=4:2:3. or a composition in the vicinity thereof, In:M:Zn=4:2:4.1 or a composition in the vicinity thereof, In:M:Zn=5:1:3 or a composition in the vicinity thereof, In:M:Zn=5:1:6 or a composition in the vicinity thereof, In:M:Zn=5:1:7 or a composition in the vicinity thereof, In:M:Zn=5:1:8 or a composition in the vicinity thereof, In:M:Zn=6:1:6 or a composition in the vicinity thereof, In:M:Zn=5:2:5 or a composition in the vicinity thereof, etc. Note that a composition in the vicinity thereof includes a range of ±30% of the desired atomic ratio.

[0370] For example, when describing a composition with an atomic ratio of In:Ga:Zn=4:2:3 or thereabout, this includes a case where, when the atomic ratio of In is 4, the atomic ratio of Ga is 1 to 3 and the atomic ratio of Zn is 2 to 4. Furthermore, when describing a composition with an atomic ratio of In:Ga:Zn=5:1:6 or thereabout, this includes a case where, when the atomic ratio of In is 5, the atomic ratio of Ga is greater than 0.1 and less than 2 and the atomic ratio of Zn is greater than 5 and less than 7. Furthermore, when describing a composition with an atomic ratio of In:Ga:Zn=1:1:1 or thereabout, this includes a case where, when the atomic ratio of In is 1, the atomic ratio of Ga is greater than 0.1 and less than 2 and the atomic ratio of Zn is greater than 0.1 and less than 2.

[0371] The crystallinity of a semiconductor material used for a transistor is not particularly limited, and any of an amorphous semiconductor and a crystalline semiconductor (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor having a crystalline region in part) may be used. The use of a crystalline semiconductor is preferable because it can suppress deterioration of transistor characteristics.

[0372] The semiconductor layer of the transistor preferably includes a metal oxide (also referred to as an oxide semiconductor). Examples of crystalline oxide semiconductors include c-axis-aligned crystalline (CAAC)-OS and nanocrystalline (nc)-OS.

[0373] Alternatively, a transistor using silicon in a channel formation region (Si transistor) may be used. Examples of silicon include single crystal silicon (single crystal Si), polycrystalline silicon, and amorphous silicon. In particular, a transistor having low temperature polysilicon (LTPS) in a semiconductor layer (hereinafter also referred to as an LTPS transistor) may be used. LTPS transistors have high field-effect mobility and good frequency characteristics.

[0374] By using Si transistors such as LTPS transistors, circuits that need to be driven at high frequencies (such as source driver circuits) can be built on the same substrate as the display unit, which simplifies the external circuits mounted on the light-emitting device and reduces component and mounting costs.

[0375] A transistor (hereinafter also referred to as an OS transistor) having a metal oxide (hereinafter also referred to as an oxide semiconductor) as a semiconductor in which a channel is formed has significantly higher field-effect mobility than a transistor using amorphous silicon. Furthermore, an OS transistor has a significantly small source-drain leakage current in an off state (hereinafter also referred to as an off-state current), and can retain charge accumulated in a capacitor connected in series with the transistor for a long period of time. Furthermore, the use of an OS transistor can reduce the power consumption of a light-emitting device.

[0376] The off-state current of an OS transistor per 1 μm of channel width at room temperature is 1 aA (1 × 10 -18 A) Below, 1zA(1×10 -21 A) or less, or 1yA (1 x 10 -24 A) or less. Note that the off-state current of a Si transistor per 1 μm of channel width at room temperature is 1 fA (1×10 -15 A) More than 1pA (1×10 -12 Therefore, it can be said that the off-state current of an OS transistor is about 10 orders of magnitude lower than that of a Si transistor.

[0377] Furthermore, to increase the light emission luminance of a light-emitting device included in a pixel circuit, it is necessary to increase the amount of current flowing through the light-emitting device. To achieve this, it is necessary to increase the source-drain voltage of the drive transistor included in the pixel circuit. Because OS transistors have a higher source-drain breakdown voltage than Si transistors, a high voltage can be applied between the source and drain of an OS transistor. Therefore, by using an OS transistor as the drive transistor included in a pixel circuit, it is possible to increase the amount of current flowing through the light-emitting device and increase the light emission luminance of the light-emitting device.

[0378] Furthermore, when the transistor operates in the saturation region, OS transistors can reduce the change in source-drain current relative to a change in gate-source voltage compared to Si transistors. Therefore, by using OS transistors as the drive transistors in pixel circuits, the current flowing between the source and drain can be precisely controlled by changing the gate-source voltage, thereby controlling the amount of current flowing through the light-emitting device. This allows for a wider range of gradations in the pixel circuit.

[0379] Furthermore, in terms of the saturation characteristics of the current that flows when a transistor operates in the saturation region, an OS transistor can pass a more stable current (saturation current) than a Si transistor, even when the source-drain voltage gradually increases. Therefore, by using an OS transistor as a drive transistor, for example, a stable current can be passed through a light-emitting device even when the current-voltage characteristics of the light-emitting device vary. In other words, when an OS transistor operates in the saturation region, the source-drain current remains almost unchanged even when the source-drain voltage increases, thereby stabilizing the light-emitting brightness of the light-emitting device.

[0380] As described above, by using an OS transistor as the drive transistor included in the pixel circuit, it is possible to achieve "suppression of black floating," "increase in light emission brightness," "multiple gradations," and "suppression of variation in light-emitting devices."

[0381] Alternatively, a semiconductor film used for a transistor in a driver circuit can be formed in the same process as a semiconductor film used for a transistor in a pixel circuit. Alternatively, the driver circuit can be formed over the same substrate as the substrate on which the pixel circuit is formed. Alternatively, the number of components constituting an electronic device can be reduced.

[0382] Silicon may also be used for the semiconductor film 508. Examples of silicon include single crystal silicon, polycrystalline silicon, and amorphous silicon. In particular, it is preferable to use a transistor having low temperature polysilicon (LTPS) in the semiconductor layer (hereinafter also referred to as an LTPS transistor). An LTPS transistor has high field-effect mobility and good frequency characteristics.

[0383] By using silicon transistors such as LTPS transistors, circuits that need to be driven at high frequencies (such as source driver circuits) can be built on the same substrate as the display unit, which simplifies the external circuits mounted on the light-emitting device and reduces component and mounting costs.

[0384] It is also preferable to use an OS transistor as at least one of the transistors included in the pixel circuit. The OS transistor has significantly higher field-effect mobility than a transistor using amorphous silicon. Furthermore, the OS transistor has a significantly smaller source-drain leakage current in an off state (hereinafter also referred to as off-current), and can retain charge accumulated in a capacitor connected in series with the transistor for a long period of time. Furthermore, the use of an OS transistor can reduce the power consumption of a light-emitting device.

[0385] By using LTPS transistors for some of the transistors included in a pixel circuit and OS transistors for the other transistors, a light-emitting device with low power consumption and high drive capability can be realized. As a more preferred example, it is preferable to use OS transistors as transistors that function as switches for controlling conduction / non-conduction between wirings, and LTPS transistors as transistors that control current. A configuration that combines both LTPS transistors and OS transistors is sometimes called LTPO. By using LTPO, a display panel with low power consumption and high drive capability can be realized.

[0386] For example, one of the transistors provided in the pixel circuit functions as a transistor for controlling the current flowing through the light-emitting device and can be called a driving transistor. One of the source and drain of the driving transistor is electrically connected to the pixel electrode of the light-emitting device. It is preferable to use an LTPS transistor as the driving transistor. This allows the current flowing through the light-emitting device in the pixel circuit to be increased.

[0387] On the other hand, another transistor provided in the pixel circuit functions as a switch for controlling pixel selection / non-selection and can also be called a selection transistor. The gate of the selection transistor is electrically connected to a gate line, and one of the source and drain is electrically connected to a source line (signal line). It is preferable to use an OS transistor as the selection transistor. This allows the gradation of the pixel to be maintained even when the frame frequency is significantly reduced (for example, 1 fps or less), so power consumption can be reduced by stopping the driver when displaying a still image.

[0388] When an oxide semiconductor is used for the semiconductor film, the device 720 has a structure in which the oxide semiconductor is used for the semiconductor film and a light-emitting device with an MML (metal maskless) structure. This structure can significantly reduce leakage current that may flow through a transistor and leakage current that may flow between adjacent light-emitting devices (also referred to as lateral leakage current or side leakage current). Furthermore, when an image is displayed on a display device, the above structure allows a viewer to observe one or more of image clarity, image sharpness, high saturation, and a high contrast ratio. Note that a structure in which leakage current that may flow through a transistor and lateral leakage current between light-emitting devices are extremely low can provide a display with extremely low light leakage (so-called floating black) that may occur during black display (also referred to as true black display).

[0389] In particular, by applying the SBS structure described above to light-emitting devices with an MML structure, the layers between light-emitting devices (for example, organic layers shared between light-emitting devices, also called common layers) are separated, resulting in a display with no or very little side leakage.

[0390] The configuration of the transistors used in the display panel may be appropriately selected depending on the screen size of the display panel. For example, when single-crystal silicon transistors are used as the transistors in the display panel, the display panel can be applied to a screen size having a diagonal size of 0.1 to 3 inches. When LTPS transistors are used as the transistors in the display panel, the display panel can be applied to a screen size having a diagonal size of 0.1 to 30 inches, preferably 1 to 30 inches. When LTPO transistors (combining LTPS transistors and OS transistors) are used in the display panel, the display panel can be applied to a screen size having a diagonal size of 0.1 to 50 inches, preferably 1 to 50 inches. When OS transistors are used as the transistors in the display panel, the display panel can be applied to a screen size having a diagonal size of 0.1 to 200 inches, preferably 50 to 100 inches.

[0391] It should be noted that it is extremely difficult to increase the size of single-crystal Si transistors due to the size of the single-crystal Si substrate. Furthermore, because LTPS transistors require a laser crystallization apparatus in their manufacturing process, it is difficult to accommodate larger screen sizes (typically, screen sizes exceeding 30 inches in diagonal size). On the other hand, OS transistors are not restricted by the need for a laser crystallization apparatus in their manufacturing process, and can be manufactured at relatively low process temperatures (typically, 450°C or lower), making them suitable for display panels with relatively large areas (typically, diagonal sizes of 50 to 100 inches). Furthermore, LTPO transistors can be applied to display panels with sizes between those of LTPS transistors and those of OS transistors (typically, diagonal sizes of 1 to 50 inches).

[0392] Next, a cross-sectional view of the light emitting and receiving device is shown in Fig. 11. Fig. 11 shows a cross-sectional view of the light emitting and receiving device shown in Fig. 9(A).

[0393] The cross-sectional view of FIG. 11 shows a cross-sectional view of a part of the region including the FPC 713 and the wiring 706, and a part of the display region 701 including the pixel 703(i,j).

[0394] 11, the light emitting and receiving device 700 has a functional layer 520 between a first substrate 510 and a second substrate 770. The functional layer 520 includes the transistors (M11, M12, M13, M14, M15, M16, M17) and capacitance elements (C2, C3) described in FIG. 10, as well as wiring (VS, VG, V1, V2, V3, V4, V5) that electrically connect these elements. Note that, in FIG. 11, the functional layer 520 includes a pixel circuit 530X(i,j), a pixel circuit 530S(i,j), and a drive circuit GD, but is not limited to this.

[0395] Furthermore, the pixel circuits formed in the functional layer 520 (for example, pixel circuits 530X(i,j) and 530S(i,j) shown in FIG. 11) are electrically connected to the light-emitting devices and light-receiving devices formed on the functional layer 520 (for example, light-emitting devices 550X(i,j) and light-receiving devices 550S(i,j) shown in FIG. 11). Specifically, the light-emitting devices 550X(i,j) are electrically connected to the pixel circuits 530X(i,j) via wiring 591X, and the light-receiving devices 550S(i,j) are electrically connected to the pixel circuits 530S(i,j) via wiring 591S. Furthermore, an insulating layer 705 is provided on the functional layer 520, the light-emitting devices, and the light-receiving devices, and the insulating layer 705 has the function of bonding the second substrate 770 and the functional layer 520 together.

[0396] Note that a substrate provided with touch sensors arranged in a matrix can be used as the second substrate 770. For example, a substrate provided with a capacitive touch sensor or an optical touch sensor can be used as the second substrate 770. In this way, the light-emitting and receiving device of one embodiment of the present invention can be used as a touch panel.

[0397] Note that the structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0398] (Embodiment 5) In this embodiment, the structure of an electronic device of one embodiment of the present invention will be described with reference to FIGS.

[0399] 12A to 14B are diagrams illustrating the structure of an electronic device of one embodiment of the present invention. FIG. 12A is a block diagram of the electronic device, and FIGS. 12B to 12E are perspective views illustrating the structure of the electronic device. FIGS. 13A to 13E are perspective views illustrating the structure of the electronic device. FIGS. 14A and 14B are perspective views illustrating the structure of the electronic device.

[0400] An electronic device 5200B described in this embodiment includes an arithmetic device 5210 and an input / output device 5220 (see FIG. 12A).

[0401] The arithmetic unit 5210 has a function of receiving operation information and a function of supplying image information based on the operation information.

[0402] The input / output device 5220 has 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 receiving image information. The input / output device 5220 also has a function for supplying detection information, a function for supplying communication information, and a function for receiving communication information.

[0403] The input unit 5240 has a function of supplying operation information. For example, the input unit 5240 supplies operation information based on an operation by the user of the electronic device 5200B.

[0404] Specifically, the input unit 5240 can use a keyboard, hardware buttons, a pointing device, a touch sensor, an illuminance sensor, an imaging device, a voice input device, a gaze input device, a posture detection device, or the like.

[0405] The display portion 5230 has a function of displaying a display panel and displaying image information. For example, the display panel described in Embodiment 3 can be used as the display portion 5230.

[0406] The detection unit 5250 has a function of supplying detection information, for example, a function of detecting the surrounding environment in which the electronic device is used and supplying the detected information.

[0407] Specifically, the detection unit 5250 can use an illuminance sensor, an imaging device, a posture detection device, a pressure sensor, a human sensor, or the like.

[0408] The communication unit 5290 has a function of receiving and supplying communication information. For example, it has a function of connecting to other electronic devices or communication networks by wireless communication or wired communication. Specifically, it has functions such as wireless local area communication, telephone communication, and short-range wireless communication.

[0409] FIG. 12B shows an electronic device having an outer shape that conforms to a cylindrical pillar or the like. An example of such an electronic device is a digital signage device. The display panel of one embodiment of the present invention can be applied to the display portion 5230. Note that the display panel may have a function of changing the display method depending on the illuminance of the usage environment. Furthermore, the display panel may have a function of detecting the presence of a person and changing the display content. This allows the display panel to be installed on a pillar of a building, for example. Alternatively, advertisements, notices, or the like can be displayed.

[0410] FIG. 12(C) shows an electronic device that has the function of generating image information based on the trajectory of a pointer used by a user. Examples include an electronic whiteboard, an electronic bulletin board, and an electronic signboard. 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.

[0411] FIG. 12D shows an electronic device that can receive information from another device and display it on the display portion 5230. An example of such an electronic device is a wearable electronic device. Specifically, several options can be displayed, or a user can select some options and send them back to the sender of the information. Alternatively, the electronic device has a function of changing the display method depending on the illuminance of the usage environment. This can reduce the power consumption of the wearable electronic device, for example. Alternatively, an image can be displayed on the wearable electronic device so that the electronic device can be used effectively even in an environment with strong external light, such as outdoors on a sunny day.

[0412] 12(E) shows an electronic device having a display portion 5230 with a curved surface that curves gently along the side surface of the housing. An example of such an electronic device is a mobile phone. The display portion 5230 includes a display panel, which has a function of displaying information on the front, side, top, and back surfaces, for example. This allows information to be displayed not only on the front surface of the mobile phone but also on the side, top, and back surfaces.

[0413] 13A shows an electronic device that can receive information from the Internet and display it on the display portion 5230. An example of such an electronic device is a smartphone. For example, a created message can be checked on the display portion 5230. Alternatively, the created message can be transmitted to another device. Alternatively, the smartphone has a function of changing the display method depending on the illuminance 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 the smartphone can be used suitably even in an environment with strong external light, such as outdoors on a sunny day.

[0414] FIG. 13B shows an electronic device in which a remote controller can be used as the input unit 5240. An example is a television system. Alternatively, information can be received from a broadcasting station or the Internet and displayed on the display unit 5230. Alternatively, a user can be photographed using the detection unit 5250. An image of the user can be transmitted. Alternatively, the user's viewing history can be acquired and provided to a cloud service. Alternatively, recommendation information can be acquired from a cloud service and displayed on the display unit 5230. Alternatively, a program or video can be displayed based on the recommendation information. Alternatively, the electronic device has a function to change the display method depending on the illuminance of the usage environment, for example. This allows images to be displayed on the television system so that it can be used appropriately even when strong external light shines indoors on a sunny day.

[0415] 13(C) shows an electronic device that can receive learning materials from the Internet and display them on the display unit 5230. One example is a tablet computer. Alternatively, a report can be input using the input unit 5240 and sent to the Internet. Alternatively, the results of corrections or evaluations of the report can be obtained from a cloud service and displayed on the display unit 5230. Alternatively, suitable learning materials can be selected and displayed based on the evaluations.

[0416] For example, an image signal can be received from another electronic device and displayed on the display unit 5230. Alternatively, the display unit 5230 can be used as a sub-display by placing the tablet computer on a stand or the like. This allows images to be displayed on the tablet computer so that the tablet computer can be used suitably even in an environment with strong external light, such as outdoors on a sunny day.

[0417] FIG. 13D shows an electronic device having a plurality of display units 5230. An example is a digital camera. For example, an image can be captured by the detection unit 5250 and displayed on the display unit 5230. 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, the captured image can be transmitted to the Internet. Alternatively, the electronic device has a function of changing the capture conditions depending on the illuminance of the usage environment. This allows the subject to be displayed on the digital camera so that it can be viewed appropriately even in an environment with strong external light, such as outdoors on a sunny day.

[0418] 13E shows an electronic device that can control another electronic device by using the electronic device of this embodiment as a master while using the other electronic device as a slave. One example is a portable personal computer. For example, part of 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 an input unit of the other electronic device using the communication unit 5290. This allows, for example, a portable personal computer to have a wide display area.

[0419] FIG. 14A shows an electronic device having a detection unit 5250 that detects acceleration or orientation. An example is a goggle-type electronic device. Alternatively, the detection unit 5250 can provide information related 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, an image of a virtual reality space that provides an immersive experience to be displayed on the goggle-type electronic device.

[0420] FIG. 14B shows an electronic device having a detection unit 5250 that detects an imaging device, acceleration, or orientation. An example is a glasses-type electronic device. Alternatively, the detection unit 5250 can provide information related 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 a real landscape and displayed. Alternatively, an image of an augmented reality space can be displayed on the glasses-type electronic device.

[0421] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0422] (Embodiment 6) In this embodiment, a structure in which the light-emitting device described in Embodiments 1 and 2 is used as a lighting device will be described with reference to Fig. 15. Fig. 15(A) is a cross-sectional view taken along line ef in the top view of the lighting device shown in Fig. 15(B).

[0423] In the lighting device of this embodiment, a first electrode 401 is formed over a light-transmitting substrate 400, which serves as a support. The first electrode 401 corresponds to the first electrode 101 in Embodiments 1 and 2. When light is extracted from the first electrode 401 side, the first electrode 401 is formed using a light-transmitting material.

[0424] A pad 412 for supplying a voltage to the second electrode 404 is formed on the substrate 400 .

[0425] An EL layer 403 is formed on the first electrode 401. The EL layer 403 has a structure corresponding to the EL layer 103 in Embodiments 1 and 2. For details of the structure, see the descriptions therein.

[0426] A second electrode 404 is formed to cover the EL layer 403. The second electrode 404 corresponds to the second electrode 102 in Embodiments 1 and 2. When light is extracted from the first electrode 401 side, the second electrode 404 is formed of a material with high reflectivity. The second electrode 404 is connected to a pad 412 to supply a voltage.

[0427] As described above, the lighting device described in this embodiment has a light-emitting device including the first electrode 401, the EL layer 403, and the second electrode 404. Since the light-emitting device has high emission efficiency, the lighting device in this embodiment can be a lighting device with low power consumption.

[0428] The substrate 400 on which the light-emitting device having the above configuration is formed is fixed to a sealing substrate 407 using sealing materials (405, 406) to seal the substrate, completing the lighting device. Either one of the sealing materials 405 or 406 may be used. Also, a desiccant may be mixed into the inner sealing material 406 (not shown in FIG. 15(B)), which can absorb moisture and improve reliability.

[0429] Furthermore, the pad 412 and a part of the first electrode 401 can be extended outside the sealing materials 405 and 406 to serve as an external input terminal. An IC chip 420 equipped with a converter or the like may also be provided thereon.

[0430] (Embodiment 7) In this embodiment, application examples of a lighting device manufactured using a light-emitting device which is one embodiment of the present invention or a light-emitting device which is a part of the light-emitting device will be described with reference to FIGS.

[0431] As an indoor lighting device, it can be applied as a ceiling light 8001. Ceiling lights 8001 are available in direct ceiling mount and recessed ceiling types. Such lighting devices are constructed by combining a light emitting device with a housing and a cover. It can also be applied to cord pendant types (hanging from the ceiling with a cord).

[0432] The footlight 8002 can also project light onto the floor, improving safety around the feet. For example, it is effective for use in bedrooms, stairs, and corridors. In this case, the size and shape can be changed appropriately depending on the size and structure of the room. It can also be used as a stationary lighting device consisting of a light-emitting device and a support base.

[0433] The sheet lighting 8003 is a thin sheet lighting device. It is attached to a wall surface and can be used for a wide range of purposes without taking up much space. It can also be easily made larger. It can also be used on curved walls, housings, etc.

[0434] It is also possible to use a lighting device 8004 in which light from a light source is controlled to only a desired direction.

[0435] The desk lamp 8005 includes a light source 8006, and the light-emitting device according to one embodiment of the present invention or a light-emitting device that is a part of the light-emitting device can be used as the light source 8006.

[0436] In addition to the above, by applying the light-emitting device of one embodiment of the present invention or a light-emitting device that is a part of the light-emitting device to a part of furniture installed in a room, the lighting device can have the function of the furniture.

[0437] As described above, various lighting devices using the light-emitting device can be obtained. Note that these lighting devices are included in one embodiment of the present invention.

[0438] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0439] (Embodiment 8) In this embodiment, a light-emitting device and a light-receiving device that can be applied to a light-emitting device of one embodiment of the present invention will be described, with reference to FIG. 17. Note that the light-emitting and receiving device 810 can also be called a light-emitting device because it includes a light-emitting device, and can also be called a light-receiving device because it includes a light-receiving device. Furthermore, since the light-emitting and receiving device 810 can be applied to a display portion of an electronic device or the like, it can also be called a display panel or a display device.

[0440] FIG. 17A is a schematic cross-sectional view of a light-emitting device 805a and a light-receiving device 805b included in a light-emitting and receiving device 810 of one embodiment of the present invention.

[0441] Light-emitting device 805a has a function of emitting light (hereinafter also referred to as a light-emitting function). Light-emitting device 805a has electrode 801a, EL layer 803a, and electrode 802. Light-emitting device 805a is preferably a light-emitting device (organic EL device) that uses the organic EL described in Embodiments 1 and 2. Therefore, EL layer 803a sandwiched between electrode 801a and electrode 802 has at least a light-emitting layer. The light-emitting layer contains a light-emitting substance. Light is emitted from EL layer 803a by applying a voltage between electrode 801a and electrode 802. 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 in addition to the light-emitting layer.

[0442] The light-receiving device 805b has a function of detecting light (hereinafter also referred to as a 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 sandwiched between the electrode 801b and the electrode 802 has at least an active layer. The light-receiving layer 803b can also be made of the same materials as those used for the various layers of the EL layer 803a described above (e.g., hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer, carrier (hole or electron) blocking layer, charge generation layer, etc.). The light-receiving device 805b functions as a photoelectric conversion device, generating charges by light incident on the light-receiving layer 803b and extracting them as a current. At this time, a voltage may be applied between the electrode 801b and the electrode 802. The amount of generated charge is determined based on the amount of light incident on the light receiving layer 803b.

[0443] The light receiving device 805b has a function of detecting visible light. The light receiving device 805b is sensitive to visible light. It is more preferable that the light receiving device 805b has a function of detecting visible light and infrared light. It is preferable that the light receiving device 805b is sensitive to visible light and infrared light.

[0444] In this specification, the blue (B) wavelength range is defined as 400 nm or more and less than 490 nm, and blue (B) light has at least one emission spectrum peak in this wavelength range. The green (G) wavelength range is defined as 490 nm or more and less than 580 nm, and green (G) light has at least one emission spectrum peak in this wavelength range. The red (R) wavelength range is defined as 580 nm or more and less than 700 nm, and red (R) light has at least one emission spectrum peak in this wavelength range. In this specification, the visible light wavelength range is defined as 400 nm or more and less than 700 nm, and visible light has at least one emission spectrum peak in this wavelength range. The infrared (IR) wavelength range is defined as 700 nm or more and less than 900 nm, and infrared (IR) light has at least one emission spectrum peak in this wavelength range.

[0445] The active layer of the light-receiving device 805b includes a semiconductor. Examples of the semiconductor include inorganic semiconductors such as silicon and organic semiconductors containing organic compounds. The light-receiving device 805b is preferably an organic semiconductor device (or an organic photodiode) whose active layer includes an organic semiconductor. Organic photodiodes can be easily made thin, lightweight, and large-area, and have high flexibility in shape and design, making them applicable to various display devices. Furthermore, using an organic semiconductor is preferable because the EL layer 803a of the light-emitting device 805a and the light-receiving layer 803b of the light-receiving device 805b can be formed by the same method (e.g., vacuum evaporation) and can use a common manufacturing equipment. The light-receiving layer 803b of the light-receiving device 805b can be formed using an organic compound according to one embodiment of the present invention.

[0446] A display device according to one embodiment of the present invention can preferably use 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 over the same substrate. Therefore, an organic photodiode can be built into a display device using an organic EL device. The display device according to one embodiment of the present invention has one or both of an imaging function and a sensing function in addition to a function of displaying an image.

[0447] The electrode 801a and the electrode 801b are provided on the same surface. Fig. 17A shows a configuration in which the electrode 801a and the electrode 801b are provided on a substrate 800. Note that the electrode 801a and the electrode 801b can be formed by, for example, processing a conductive film formed on the substrate 800 into an island shape. That is, the electrode 801a and the electrode 801b can be formed through the same process.

[0448] A substrate having heat resistance sufficient to withstand the formation of the light-emitting device 805a and the light-receiving device 805b can be used as the substrate 800. When an insulating substrate is used as the substrate 800, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, an organic resin substrate, or the like can be used. In addition, a semiconductor substrate such as a single-crystal semiconductor substrate made of silicon or silicon carbide, a polycrystalline semiconductor substrate, a compound semiconductor substrate such as silicon germanium, or an SOI substrate can be used.

[0449] In particular, it is preferable to use a substrate in which a semiconductor circuit including semiconductor elements such as transistors is formed on the aforementioned insulating substrate or semiconductor substrate as the substrate 800. The semiconductor circuit preferably constitutes, for example, a pixel circuit, a gate line driving circuit (gate driver), a source line driving circuit (source driver), etc. In addition to the above, an arithmetic circuit, a memory circuit, etc. may also be configured.

[0450] The electrode 802 is an electrode made of a layer common to the light-emitting device 805a and the light-receiving device 805b. Of these electrodes, a conductive film that transmits visible light and infrared light is used for the electrode that emits or receives light. It is preferable that a conductive film that reflects visible light and infrared light is used for the electrode that does not emit or receive light.

[0451] In the display device according to one embodiment of the present invention, an electrode 802 functions as one electrode of each of a light-emitting device 805a and a light-receiving device 805b.

[0452] 17(B) shows a case where electrode 801a of light-emitting device 805a has a higher potential than electrode 802. In this case, electrode 801a functions as the anode of light-emitting device 805a, and electrode 802 functions as the cathode. Electrode 801b of light-receiving device 805b has a lower potential than electrode 802. Note that in FIG. 17(B), to make it easier to understand the direction of current flow, the circuit symbol for a light-emitting diode is shown to the left of light-emitting device 805a, and the circuit symbol for a photodiode is shown to the right of light-receiving device 805b. The direction of carrier (electron and hole) flow is also indicated by arrows in each device.

[0453] In the configuration shown in Figure 17(B), when a first potential is supplied to electrode 801a via a first wiring, a second potential is supplied to electrode 802 via a second wiring, and a third potential is supplied to electrode 801b via a third wiring, the relationship in magnitude of each potential is first potential > second potential > third potential.

[0454] 17(C) shows a case where electrode 801a of light-emitting device 805a has a lower potential than electrode 802. In this case, electrode 801a functions as the cathode of light-emitting device 805a, and electrode 802 functions as the anode. Electrode 801b of light-receiving device 805b has a lower potential than electrode 802 and a higher potential than electrode 801a. In FIG. 17(C), to make it easier to understand the direction of current flow, the circuit symbol for a light-emitting diode is shown to the left of light-emitting device 805a, and the circuit symbol for a photodiode is shown to the right of light-receiving device 805b. The direction of carrier (electron and hole) flow is also indicated by arrows in each device.

[0455] In the configuration shown in Figure 17(C), when a first potential is supplied to electrode 801a via a first wiring, a second potential is supplied to electrode 802 via a second wiring, and a third potential is supplied to electrode 801b via a third wiring, the relationship in magnitude of each potential is second potential > third potential > first potential.

[0456] FIG. 18(A) shows a light-receiving and light-emitting device 810A, which is a modified example of the light-receiving and light-emitting device 810. The light-receiving and light-emitting device 810A differs from the light-receiving and light-emitting device 810 in that it includes a common layer 806 and a common layer 807. In the light-emitting device 805a, the common layer 806 and the common layer 807 function as part of the EL layer 803a. In the light-receiving device 805b, the common layer 806 and the common layer 807 function as part of the light-receiving layer 803b. The common layer 806 includes, for example, a hole injection layer and a hole transport layer. The common layer 807 includes, for example, an electron transport layer and an electron injection layer.

[0457] By adopting a configuration including the common layer 806 and the common layer 807, it is possible to incorporate a light receiving device without significantly increasing the number of times of coating, and it is possible to manufacture the light receiving and emitting device 810A with high throughput.

[0458] FIG. 18(B) shows a light-receiving and light-emitting device 810B, which is a modification of the light-receiving and light-emitting device 810. The light-receiving and light-emitting device 810B differs from the light-receiving and light-emitting device 810 in that the EL layer 803a includes layers 806a and 807a, and the light-receiving layer 803b includes layers 806b and 807b. The layers 806a and 806b are made of different materials and include, for example, a hole injection layer and a hole transport layer. The layers 806a and 806b may be made of the same material. The layers 807a and 807b are made of different materials and include, for example, an electron transport layer and an electron injection layer. The layers 807a and 807b may be made of the same material.

[0459] By selecting the optimum materials for constituting the light-emitting device 805a for the layers 806a and 807a, and the optimum materials for constituting the light-receiving device 805b for the layers 806b and 807b, the performance of each of the light-emitting device 805a and the light-receiving device 805b in the light-receiving and light-emitting device 810B can be improved.

[0460] Note that the resolution of the light-receiving device 805b described in this embodiment can be 100 ppi or more, preferably 200 ppi or more, more preferably 300 ppi or more, more preferably 400 ppi or more, and further preferably 500 ppi or more, and can be 2000 ppi or less, 1000 ppi or less, or 600 ppi or less. In particular, the light-receiving device 805b can be suitably used for imaging a fingerprint by being arranged with a resolution of 200 ppi or more and 600 ppi or less, preferably 300 ppi or more and 600 ppi or less. When fingerprint authentication is performed using the display device of one embodiment of the present invention, increasing the resolution of the light-receiving device 805b can, for example, extract fingerprint minutiae with high accuracy, thereby improving the accuracy of fingerprint authentication. Furthermore, a resolution of 500 ppi or more is preferable because it can comply with standards such as those of the National Institute of Standards and Technology (NIST). Assuming that the resolution of the light receiving device is 500 ppi, the size of each pixel is 50.8 μm, which is sufficient resolution to capture the width of a fingerprint (typically 300 μm to 500 μm).

[0461] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments. [Example]

[0462] In this example, light-emitting device 1 and light-emitting device 2 according to one embodiment of the present invention, and comparative light-emitting device 3 were fabricated and their characteristics were compared. The structural formulae of organic compounds used in light-emitting device 1, light-emitting device 2, and comparative light-emitting device 3 are shown below. The device structures of light-emitting device 1, light-emitting device 2, and comparative light-emitting device 3 are also shown.

[0463] [ka]

[0464] [Table 1]

[0465] <<Fabrication of Light-Emitting Device 1>> The light-emitting device 1 shown in this example 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, as shown in Figure 19, and a second electrode 902 is stacked on the electron injection layer 915.

[0466] First, a first electrode 901 was formed on a substrate 900. The electrode area was 4 mm 2 The dimensions of the substrate 900 were 2 mm x 2 mm. A glass substrate was used as the substrate 900. The first electrode 901 was formed by depositing indium tin oxide containing silicon oxide (ITSO) to a thickness of 70 nm by sputtering. In this example, the first electrode 901 functions as an anode.

[0467] 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. -4 The substrate was placed in a vacuum deposition apparatus whose internal pressure had been reduced to about Pa, and vacuum-baked at 170°C for 60 minutes in the heating chamber of the vacuum deposition apparatus, after which the substrate was allowed to cool for about 30 minutes.

[0468] Next, a hole injection layer 911 was formed on the first electrode 901. The hole injection layer 911 was formed by evaporating the solution in a vacuum evaporation apparatus for 10 minutes. -4 After reducing the pressure to 10 Pa, N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF) and a fluorine-containing electron acceptor material (OCHD-003) with a molecular weight of 672 were co-evaporated to a thickness of 10 nm at a weight ratio of 1:0.03 (= PCBBiF:OCHD-003).

[0469] Next, a hole transport layer 912 was formed on the hole injection layer 911. The hole transport layer 912 was formed by evaporating PCBBiF to a thickness of 20 nm, and then evaporating N-(2-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: oFrBiF) (structural formula (105)) to a thickness of 10 nm.

[0470] Next, a light-emitting layer 913 was formed on the hole-transporting layer 912 .

[0471] The light-emitting layer 913 was formed to a thickness of 25 nm by co-evaporation of 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth), oFrBiF, and 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b′]bisbenzofuran (abbreviation: 3,10PCA2Nbf(IV)-02) in a weight ratio of αN-βNPAnth:oFrBiF:3,10PCA2Nbf(IV)-02 = 0.9:0.1:0.015.

[0472] Next, an electron transport layer 914 was formed on the light-emitting layer 913. The electron transport layer 914 was formed by evaporating 2-[3′-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II) to a thickness of 10 nm, and then evaporating 2,9-di(2-naphthyl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen) to a thickness of 15 nm.

[0473] Next, an electron injection layer 915 was formed on the electron transport layer 914. The electron injection layer 915 was formed by vapor deposition using lithium fluoride (LiF) so as to have a film thickness of 1 nm.

[0474] Next, a second electrode 902 was formed on the electron injection layer 915. The second electrode 902 was formed by evaporating aluminum (Al) to a film thickness of 150 nm. In this example, the second electrode 902 functions as a cathode.

[0475] The above steps were used to fabricate the light-emitting device 1. Next, the methods for fabricating the light-emitting device 2 and the comparative light-emitting device 3 will be described.

[0476] <<Fabrication of light-emitting device 2>> Light-emitting device 2 differs from light-emitting device 1 in that the mixture ratio of αN-βNPAnth, oFrBiF, and 3,10PCA2Nbf(IV)-O2 used in light-emitting layer 913 is different. That is, in light-emitting device 2, light-emitting layer 913 was formed by co-evaporating αN-βNPAnth, oFrBiF, and 3,10PCA2Nbf(IV)-O2 in a weight ratio of αN-βNPAnth:oFrBiF:3,10PCA2Nbf(IV)-O2 = 0.7:0.3:0.015 to a thickness of 25 nm. The rest of the fabrication process was the same as for light-emitting device 1.

[0477] <<Fabrication of Comparative Light-Emitting Device 3>> Comparative light-emitting device 3 differs from light-emitting device 1 in that oFrBiF is not used in the light-emitting layer 913. That is, in comparative light-emitting device 3, light-emitting layer 913 was formed by co-evaporating αN-βNPAnth and 3,10PCA2Nbf(IV)-O2 in a weight ratio of αN-βNPAnth:3,10PCA2Nbf(IV)-O2 = 1:0.015 to a thickness of 25 nm. Other aspects were fabricated in the same manner as light-emitting device 1.

[0478] The above-mentioned light-emitting device 1, light-emitting device 2, and comparative light-emitting device 3 were sealed with glass substrates in a nitrogen atmosphere glove box to prevent exposure to the atmosphere (a sealant was applied around the elements, and UV treatment and heat treatment at 80°C for 1 hour were performed during sealing), and then the initial characteristics of these light-emitting devices were measured.

[0479] The luminance-current density characteristics of light-emitting device 1, light-emitting device 2, and comparative light-emitting device 3 are shown in Figure 20, their current efficiency-luminance characteristics in Figure 21, their luminance-voltage characteristics in Figure 22, their current-voltage characteristics in Figure 23, their blue index-luminance characteristics in Figure 24, their external quantum efficiency-luminance characteristics in Figure 25, and their emission spectra in Figure 26.

[0480] The blue index (BI) is calculated by dividing the current efficiency (cd / A) by the y chromaticity calculated using the CIE 1931 color system. It is an index of blue emission characteristics. The smaller the y chromaticity, the higher the color purity of blue emission. High-color-purity blue emission can express a wide range of blue colors. Furthermore, when fabricating a white panel, using blue-emitting pixels with such high color purity reduces the required luminance to express blue, thereby reducing the overall power consumption of the panel. However, such high-color-purity blue emission also reduces the relative luminous efficiency, which corresponds to the sensitivity of the human eye. Furthermore, current efficiency, which uses luminance, a physical quantity affected by the standard relative luminous efficiency, varies significantly depending on the color. Therefore, the BI, which takes into account the y chromaticity, an index of blue purity, is preferably used as a means of expressing blue emission efficiency. Therefore, a light-emitting device with a higher BI can be said to have better efficiency as a blue-emitting device for use in displays.

[0481] In addition, each light-emitting device has a 1000cd / m 2 The main characteristics in this range are shown in the table below. A spectroradiometer (SR-UL1R, manufactured by Topcon Corporation) was used to measure the luminance, CIE chromaticity, and emission spectrum. The external quantum efficiency was calculated using the luminance and emission spectrum measured in front of the substrate using the spectroradiometer, assuming that the light distribution characteristics of the light emitted from the device are Lambertian.

[0482] [Table 2]

[0483] 20 to 26 show that the light-emitting device 1 and the light-emitting device 2 of one embodiment of the present invention have favorable characteristics. Furthermore, FIG. 23 and the above table show that the current-voltage characteristics of the light-emitting device 1 and the light-emitting device 2 are improved compared to the comparative light-emitting device 3. This is because the addition of an organic compound having a low HOMO level and a hole-transporting property to the light-emitting layer 913 facilitates hole injection into the light-emitting layer 913. This shows that the current-voltage characteristics of a light-emitting device of one embodiment of the present invention, which includes the light-emitting substance (3,10PCA2Nbf(IV)-02), the first organic compound (αN-βNPAnth), and the second organic compound (oFrBiF) in the light-emitting layer 913, can be improved compared to a light-emitting device that does not include the second organic compound. [Example]

[0484] In this example, a light-emitting device 4 according to one embodiment of the present invention and a comparative light-emitting device 5 were fabricated and their characteristics were compared. The structural formulae of organic compounds used in the light-emitting device 4 and the comparative light-emitting device 5 are shown below. The element structures of the light-emitting device 4 and the comparative light-emitting device 5 are also shown.

[0485] [ka]

[0486] [Table 3]

[0487] <<Fabrication of Light-Emitting Device 4>> The light emitting device 4 shown in this example has the same layered structure as in Example 2, as shown in FIG.

[0488] First, a first electrode 901 was formed on a substrate 900. The electrode area was 4 mm 2The dimensions of the substrate 900 were 2 mm x 2 mm. A glass substrate was used as the substrate 900. The first electrode 901 was formed by depositing indium tin oxide containing silicon oxide (ITSO) to a thickness of 70 nm by sputtering. In this example, the first electrode 901 functions as an anode.

[0489] 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. -4 The substrate was placed in a vacuum deposition apparatus whose internal pressure had been reduced to about Pa, and vacuum-baked at 170°C for 60 minutes in the heating chamber of the vacuum deposition apparatus, after which the substrate was allowed to cool for about 30 minutes.

[0490] Next, a hole injection layer 911 was formed on the first electrode 901. The hole injection layer 911 was formed by evaporating the solution in a vacuum evaporation apparatus for 10 minutes. -4 After the pressure was reduced to 0.05 Pa, PCBBiF and OCHD-003 were co-deposited in a weight ratio of 1:0.03 (=PCBBiF:OCHD-003) to form a 10 nm thick film.

[0491] Next, a hole transport layer 912 was formed on the hole injection layer 911. The hole transport layer 912 was formed by depositing PCBBiF to a thickness of 20 nm and then depositing oFrBiF to a thickness of 10 nm.

[0492] Next, a light-emitting layer 913 was formed on the hole-transporting layer 912 .

[0493] The light-emitting layer 913 was formed by co-evaporating oFrBiF and 3,10PCA2Nbf(IV)-O2 in a weight ratio of oFrBiF:3,10PCA2Nbf(IV)-O2 = 1:0.015 to a thickness of 5 nm, and then by co-evaporating αN-βNPAnth and 3,10PCA2Nbf(IV)-O2 in a weight ratio of αN-βNPAnth:3,10PCA2Nbf(IV)-O2 = 1:0.015 to a thickness of 20 nm.

[0494] Next, an electron transport layer 914 was formed on the light-emitting layer 913. The electron transport layer 914 was formed by depositing 2mDBTBPDBq-II to a thickness of 10 nm, and then depositing NBPhen to a thickness of 15 nm.

[0495] Next, an electron injection layer 915 was formed on the electron transport layer 914. The electron injection layer 915 was formed by vapor deposition using lithium fluoride (LiF) so as to have a film thickness of 1 nm.

[0496] Next, a second electrode 902 was formed on the electron injection layer 915. The second electrode 902 was formed by evaporating aluminum (Al) to a film thickness of 150 nm. In this example, the second electrode 902 functions as a cathode.

[0497] Through the above steps, the light-emitting device 4 was fabricated. Next, the method for fabricating the comparative light-emitting device 5 will be described.

[0498] <<Preparation of Comparative Light-Emitting Device 5>> Comparative light-emitting device 5 differs from light-emitting device 4 in that oFrBiF is not used in the light-emitting layer 913. That is, in comparative light-emitting device 5, light-emitting layer 913 was formed by co-evaporating αN-βNPAnth and 3,10PCA2Nbf(IV)-O2 in a weight ratio of αN-βNPAnth:3,10PCA2Nbf(IV)-O2 = 1:0.015 to a thickness of 25 nm. Other aspects were fabricated in the same manner as light-emitting device 4.

[0499] The above-mentioned light-emitting device 4 and comparative light-emitting device 5 were sealed with a glass substrate in a nitrogen atmosphere glove box to prevent exposure to the atmosphere (a sealant was applied around the elements, and UV treatment and heat treatment at 80°C for 1 hour were performed during sealing), and then the initial characteristics of these light-emitting devices were measured.

[0500] The luminance-current density characteristics of light-emitting device 4 and comparative light-emitting device 5 are shown in Figure 27, their current efficiency-luminance characteristics in Figure 28, their luminance-voltage characteristics in Figure 29, their current-voltage characteristics in Figure 30, their blue index-luminance characteristics in Figure 31, their external quantum efficiency-luminance characteristics in Figure 32, and their emission spectra in Figure 33.

[0501] In addition, each light-emitting device has a 1000cd / m 2 The main characteristics in this range are shown in the table below. A spectroradiometer (SR-UL1R, manufactured by Topcon Corporation) was used to measure the luminance, CIE chromaticity, and emission spectrum. The external quantum efficiency was calculated using the luminance and emission spectrum measured using the spectroradiometer, assuming that the light distribution characteristics of the light emitted from the device are Lambertian.

[0502] [Table 4]

[0503] 27 to 33 show that the light-emitting device 4 of one embodiment of the present invention has favorable characteristics. Furthermore, FIG. 30 and the above table show that the current-voltage characteristics of the light-emitting device 4 are improved compared to those of the comparative light-emitting device 5. This is probably because the use of the second organic compound, which has a low HOMO level and a hole-transporting property, on the anode side of the light-emitting layer 913 reduces the difference in HOMO levels between the hole-transport layer 912 and the light-emitting layer 913, thereby facilitating hole injection into the light-emitting layer 913. This shows that the light-emitting device of one embodiment of the present invention, which includes the light-emitting substance (3,10PCA2Nbf(IV)-02), the first organic compound (αN-βNPAnth), and the second organic compound (oFrBiF) in the light-emitting layer 913, can improve the current-voltage characteristics compared to a light-emitting device that does not include the second organic compound. [Explanation of symbols]

[0504] GD drive circuit IR subpixel M11 transistor M12 transistor M13 transistor M14 transistor M15 transistor M16 transistor M17 transistor MS wiring PS subpixel REG resist mask RES wiring SE1 wiring SE distance Si single crystal TX wiring VG wiring VS wiring 100 Light-emitting devices 101 first electrode 102 second electrode 103 EL layer 103a EL layer 103b EL layer 103B EL layer 103G EL layer 103R EL layer 103PS light receiving layer 104B Hole injection / transport layer 104G Hole injection / transport layer 104R Hole injection / transport layer 104PS First Transport Layer 105B Light-emitting layer 105G light-emitting layer 105R luminous layer 105PS active layer 106 Charge generation layer 106a Charge generation layer 106b Charge generation layer 107 Insulating layer 108B Electron transport layer 108G electron transport layer 108R Electron transport layer 108PS Second Transport Layer 109 Electron injection layer 110B Sacrificial layer 110G sacrificial layer 110R sacrificial layer 110PS sacrificial layer 111 Hole injection layer 111a Hole injection layer 111b Hole injection layer 112 Hole transport layer 112a Hole transport layer 112b hole transport layer 113 Light-emitting layer 113a Light-emitting layer 113b Light-emitting layer 113c Light-emitting layer 114 Electron transport layer 114a Electron transport layer 114b Electron transport layer 115 Electron injection layer 115a Electron injection layer 115b Electron injection layer 130 Connection 140 Second insulating layer 400 boards 401 First electrode 403 EL layer 404 Second electrode 405 Sealing material 406 Sealing material 407 Sealing substrate 412 Pad 420 IC chip 501C insulating film 501D insulating film 504 Conductive film 506 Insulating film 508 Semiconductor film 508A area 508B area 508C area 510 first substrate 512A Conductive film 512B Conductive film 516 Insulating film 516A Insulating film 516B insulating film 518 Insulating film 520 Functional Layer 524 Conductive film 528 Bulkhead 530 pixel circuit 530S pixel circuit 530X pixel circuit 531 Pixel Circuit 550 Light-emitting devices 550B Light Emitting Device 550G Light Emitting Device 550R Light Emitting Device 550X Light Emitting Device 550PS light receiving device 550S Light Receiving Device 551B Electrode 551C connecting electrode 551G electrode 551R electrode 551PS electrode 552 Electrode 580 Gap 591X wiring 591S wiring 700 Light receiving and emitting device 701 Display area 702B subpixel 702G subpixel 702R subpixel 702PS subpixels 702IR subpixels 703 pixels 704 circuits 705 Insulation Layer 706 Wiring 710 board 711 Circuit Board 712 IC 713 FPC 720 equipment 770 PCB 800 boards 801a electrode 801b electrode 802 Electrode 803a EL layer 803b Photosensitive layer 805a Light-emitting devices 805b Light receiving device 810 Light receiving and emitting device 810A Light emitting / receiving device 810B Light receiving and emitting device 900 boards 901 First electrode 902 Second electrode 911 Hole injection layer 912 Hole transport layer 913 Light-emitting layer 914 Electron transport layer 915 Electron injection layer 5200B Electronic equipment 5210 Arithmetic unit 5220 I / O device 5230 Display section 5240 input section 5250 Detection unit 5290 Communications Department 8001 Ceiling Light 8002 Footlight 8003 Sheet lighting 8004 Lighting equipment 8005 Desk lamp 8006 light source

Claims

1. At least a light-emitting layer is provided between an anode and a cathode, the light-emitting layer includes a light-emitting material, a first organic compound, and a second organic compound; the luminescent material is a material that exhibits fluorescent light, the first organic compound has at least one of an anthracene skeleton, a tetracene skeleton, a phenanthrene skeleton, a pyrene skeleton, a chrysene skeleton, a carbazole skeleton, a benzocarbazole skeleton, a dibenzocarbazole skeleton, a dibenzofuran skeleton, a benzonaphthofuran skeleton, a bisnaphthofuran skeleton, a dibenzothiophene skeleton, a benzonaphthothiophene skeleton, a bisnaphthothiophene skeleton, and a fluoranthene skeleton; the second organic compound has an arylamine skeleton, a light-emitting device, wherein the arylamine skeleton has any one of a fluorenyl group, a spirobifluorenyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzofuranyl group, a benzonaphthofuranyl group, a bisnaphthofuranyl group, a dibenzothiophenyl group, a benzonaphthothiophenyl group, and a bisnaphthothiophenyl group.

2. At least a light-emitting layer is provided between an anode and a cathode, the light-emitting layer includes a light-emitting material, a first organic compound, and a second organic compound; the luminescent material is a material that exhibits fluorescent light, the first organic compound has at least one of an anthracene skeleton, a tetracene skeleton, a phenanthrene skeleton, a pyrene skeleton, a chrysene skeleton, a carbazole skeleton, a benzocarbazole skeleton, a dibenzocarbazole skeleton, a dibenzofuran skeleton, a benzonaphthofuran skeleton, a bisnaphthofuran skeleton, a dibenzothiophene skeleton, a benzonaphthothiophene skeleton, a bisnaphthothiophene skeleton, and a fluoranthene skeleton; The second organic compound is a light-emitting device represented by general formula (G1). 【Chemical 1】 (In general formula (G1), Ar １ represents a substituted or unsubstituted aryl group having 6 to 30 carbon atoms; Ar ２ and Ar ３ each independently represent any one of a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted spirobifluorenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted benzocarbazolyl group, a substituted or unsubstituted dibenzocarbazolyl group, a substituted or unsubstituted benzonaphthofuranyl group, a substituted or unsubstituted bisnaphthofuranyl group, a substituted or unsubstituted benzonaphthothiophenyl group, and a substituted or unsubstituted bisnaphthothiophenyl group; A １ or A ３ represents a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, and n, m, and k represent integers of 0 to 2. １ ~Ar ３ and A １ or A ３ When one or more of the above groups have one or more substituents, the substituents are each independently an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms. Note that the aryl group does not include a heteroaryl group. In addition, the substituents may be bonded to each other to form a ring.

3. At least a light-emitting layer is provided between an anode and a cathode, the light-emitting layer includes a light-emitting material, a first organic compound, and a second organic compound; the luminescent material is a material that exhibits fluorescent light, the first organic compound has at least one of an anthracene skeleton, a tetracene skeleton, a phenanthrene skeleton, a pyrene skeleton, a chrysene skeleton, a carbazole skeleton, a benzocarbazole skeleton, a dibenzocarbazole skeleton, a dibenzofuran skeleton, a benzonaphthofuran skeleton, a bisnaphthofuran skeleton, a dibenzothiophene skeleton, a benzonaphthothiophene skeleton, a bisnaphthothiophene skeleton, and a fluoranthene skeleton; The second organic compound is a light-emitting device represented by general formula (G2). 【Chemistry 2】 (In general formula (G2), Ar １ represents a substituted or unsubstituted aryl group having 6 to 30 carbon atoms; Ar ２ and Ar ３ each independently represents any one of a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted spirobifluorenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted benzocarbazolyl group, a substituted or unsubstituted dibenzocarbazolyl group, a substituted or unsubstituted benzonaphthofuranyl group, a substituted or unsubstituted bisnaphthofuranyl group, a substituted or unsubstituted benzonaphthothiophenyl group, and a substituted or unsubstituted bisnaphthothiophenyl group. １ ~Ar ３ When one or more of the groups have one or more substituents, the substituents are each independently an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms. Note that the aryl group does not include a heteroaryl group. In addition, the substituents may be bonded to each other to form a ring.

4. At least a light-emitting layer is provided between an anode and a cathode, the light-emitting layer includes a light-emitting material, a first organic compound, and a second organic compound; the luminescent material is a material that exhibits fluorescent light, the first organic compound has at least one of an anthracene skeleton, a tetracene skeleton, a phenanthrene skeleton, a pyrene skeleton, a chrysene skeleton, a carbazole skeleton, a benzocarbazole skeleton, a dibenzocarbazole skeleton, a dibenzofuran skeleton, a benzonaphthofuran skeleton, a bisnaphthofuran skeleton, a dibenzothiophene skeleton, a benzonaphthothiophene skeleton, a bisnaphthothiophene skeleton, and a fluoranthene skeleton; The second organic compound is a light-emitting device represented by general formula (G3). 【Chemistry 3】 (In general formula (G3), Ar １ represents a substituted or unsubstituted aryl group having 6 to 30 carbon atoms; Ar ３ represents any one of a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted spirobifluorenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted benzocarbazolyl group, a substituted or unsubstituted dibenzocarbazolyl group, a substituted or unsubstituted benzonaphthofuranyl group, a substituted or unsubstituted bisnaphthofuranyl group, a substituted or unsubstituted benzonaphthothiophenyl group, and a substituted or unsubstituted bisnaphthothiophenyl group; R １ ~R ９ each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms. １ and Ar ３ When one or both of the groups have one or more substituents, the substituents are each independently an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 13 carbon atoms. Note that the aryl group does not include a heteroaryl group. In addition, the substituents may be bonded to each other to form a ring.

5. At least a light-emitting layer is provided between an anode and a cathode, the light-emitting layer includes a light-emitting material, a first organic compound, and a second organic compound; the luminescent material is a material that exhibits fluorescent light, the first organic compound has at least one of an anthracene skeleton, a tetracene skeleton, a phenanthrene skeleton, a pyrene skeleton, a chrysene skeleton, a carbazole skeleton, a benzocarbazole skeleton, a dibenzocarbazole skeleton, a dibenzofuran skeleton, a benzonaphthofuran skeleton, a bisnaphthofuran skeleton, a dibenzothiophene skeleton, a benzonaphthothiophene skeleton, a bisnaphthothiophene skeleton, and a fluoranthene skeleton; The second organic compound is a light-emitting device represented by general formula (G4). 【Chemistry 4】 (In general formula (G4), X represents oxygen or sulfur, and R ２１ and R ２２ and R ３１ ~R ３７ each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms; R ３８ ~R ４６ each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms; R ４７ ~R ５３ Each of R independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 13 carbon atoms. The aryl group does not include a heteroaryl group. ２１ and R ２２ and R ３１ ~R ３７ At least two of the groups represented by R may be bonded to each other to form a ring. ３８ ~R ４６ At least two of the groups represented by R may be bonded to each other to form a ring. ４７ ~R ５３ At least two of the groups represented by the formula (I) may be bonded to each other to form a ring.

6. In any one of claims 1 to 5, A light-emitting device, wherein the difference between the lowest singlet excitation level and the lowest triplet excitation level of the light-emitting substance is 0.3 eV or more.

7. In any one of claims 1 to 5, A light-emitting device, wherein the light-emitting material is a material that emits blue light.

8. A light emitting apparatus comprising the light emitting device according to claim 1 and at least one of a transistor and a substrate.

9. An electronic device comprising: the light-emitting device according to claim 8; and at least one of a detection unit, an input unit, and a communication unit.

10. A lighting device comprising the light-emitting device according to claim 8 and a housing.

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