Light emitting device

Abstract

Provided is a light-emitting device having high luminous efficiency. The light emitting device includes an organic compound layer between an anode and a cathode. The organic compound layer includes at least a light-emitting layer and an electron injection layer. The light-emitting layer contains a light-emitting substance. The electron injection layer is a mixed layer of a first organic compound and a second organic compound. The first organic compound has strong basicity, and the second organic compound has an electron transport property. The electron injection layer has an ordinary light refractive index of 1.50 or more and less than 1.75 with respect to an arbitrary wavelength in the range of 455 nm or more and 465 nm or less.

Description

Technical Field

[0001] One aspect of the present invention relates to an organic compound, a light-emitting device, a light-emitting apparatus, a light-receiving apparatus, a display device, an electronic device, a lighting device, and an electronic device. Note that one aspect of the present invention is not limited to the above technical field. One aspect of the invention disclosed in this specification and the like relates to an article, a method, or a manufacturing method. One aspect of the present invention relates to a process, a machine, a manufacture, or a composition of matter. Thus, more specifically, as an example of the technical field of one aspect of the present invention disclosed in this specification, a semiconductor device, a display device, a liquid crystal display device, a light-emitting device, a lighting device, a power storage device, a storage device, an imaging device, a driving method of these devices, or a manufacturing method of these devices can be cited. Background Art

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

[0003] Since such a light-emitting device is a self-luminous type light-emitting device, when used for pixels of a display, it has advantages such as higher visibility and no need for a backlight compared to liquid crystals. Therefore, this light-emitting device is suitable for flat panel display elements. In addition, a display using such a light-emitting device can be manufactured to be thin and light, which is also a great advantage. Moreover, a very fast response speed is also one of its characteristics.

[0004] Furthermore, since the light-emitting layer of such a light-emitting device can be formed continuously in two dimensions, surface light emission can be obtained. Since this is a characteristic that is difficult to obtain in a point light source typified by an incandescent lamp or an LED, or a linear light source typified by a fluorescent lamp, the above light-emitting device also has high utility value as a surface light source applicable to lighting and the like.

[0005] As described above, a display or a lighting device using a light-emitting device is applicable to various electronic devices, and research and development are increasingly active in order to pursue a light-emitting device having better characteristics.

[0006] As an organic thin film that can provide good electron injection and electron transport properties when used as an electron injection layer in an organic EL device, for example, a single film comprising a hexahydropyrimidopyrimidine compound and a second material that transports electrons, or a laminated film comprising a film comprising a hexahydropyrimidopyrimidine compound and a film comprising a second material is known (Patent Document 1 and Non-Patent Document 1).

[0007] In addition, low light extraction efficiency is one of the problems related to organic EL devices. In particular, attenuation caused by reflection due to the difference in refractive index between adjacent layers is the main reason for the decrease in efficiency of EL devices. In order to reduce this effect, a structure in which a layer formed of a low refractive index material is formed inside the EL layer is proposed (for example, refer to non-patent document 2). [Prior technical literature] [Patent Document]

[0008] [Patent Document 1] International Patent Application Publication No. 2021 / 045178 [Non-patent literature]

[0009] [Non-patent document 1] Tsubasa Sasaki et al., "Unravelling the electroninjection / transport mechanism in organic light-emitting diodes", Nature Communications, 12, 2706 (2021) [Non-patent document 2] Jaeho Lee et al., "Synergetic electrode architecture for efficient graphene-based flexible organic light-emitting diodes", Nature Communications, 7, 11791 (2016) Summary of the invention Technical problem to be solved by the invention

[0010] One of the objects of one embodiment of the present invention is to provide a light-emitting device with high luminous efficiency. One of the objects of one embodiment of the present invention is to provide a light-emitting device with low power consumption. One of the objects of one embodiment of the present invention is to provide a light-emitting device with good reliability. One of the objects of one embodiment of the present invention is to provide a light-emitting device with high design freedom in the manufacturing process. One of the objects of one embodiment of the present invention is to provide a high-definition light-emitting device. One of the objects of one embodiment of the present invention is to provide a novel light-emitting device. One of the objects of one embodiment of the present invention is to provide a light-emitting device, a light-emitting apparatus, an electronic device, a display device, and an electronic device including the above-described light-emitting device.

[0011] Note that the description of these objects does not preclude the existence of other objects. Note that one embodiment of the present invention does not need to achieve all of the above objects. Note that objects other than the above can be known and extracted from the description of the specification, drawings, claims, etc. Means for Solving Technical Problems

[0012] One embodiment of the present invention is a light-emitting device including an organic compound layer between an anode and a cathode. The organic compound layer includes at least a light-emitting layer and an electron injection layer. The light-emitting layer contains a light-emitting substance. The electron injection layer is a mixed layer of a first organic compound and a second organic compound. The first organic compound has strong basicity, and the second organic compound has electron-transporting properties. The ordinary light refractive index of the electron injection layer with respect to any wavelength in the range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.75.

[0013] One embodiment of the present invention is a light-emitting device including an organic compound layer between an anode and a cathode. The organic compound layer includes at least a light-emitting layer and an electron injection layer. The light-emitting layer contains a light-emitting substance. The electron injection layer is a mixed layer of a first organic compound and a second organic compound. The first organic compound has strong basicity, and the second organic compound has electron-transporting properties. The ordinary light refractive index of the electron injection layer with respect to the wavelength of 633 nm is 1.45 or more and less than 1.70.

[0014] One embodiment of the present invention is a light-emitting device including an organic compound layer between an anode and a cathode. The organic compound layer includes at least a light-emitting layer and an electron injection layer. The light-emitting layer contains a light-emitting substance. The electron injection layer is a mixed layer of a first organic compound and a second organic compound. The first organic compound has strong basicity, and the second organic compound has electron-transporting properties. The value obtained by adding the ordinary light refractive index of the first organic compound with respect to any wavelength in the range of 455 nm or more and 465 nm or less and dividing the sum by 2 with the ordinary light refractive index of the second organic compound with respect to any wavelength in the range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.75.

[0015] One embodiment of the present invention is a light-emitting device including an organic compound layer between an anode and a cathode. The organic compound layer includes at least a light-emitting layer and an electron injection layer. The light-emitting layer contains a light-emitting substance. The electron injection layer is a mixed layer of a first organic compound and a second organic compound. The first organic compound has strong basicity, and the second organic compound has electron-transporting properties. The value obtained by adding the ordinary light refractive index of the first organic compound with respect to the wavelength of 633 nm and dividing the sum by 2 with the ordinary light refractive index of the second organic compound with respect to the wavelength of 633 nm is 1.45 or more and less than 1.70.

[0016] One embodiment of the present invention is a light-emitting device including an organic compound layer between an anode and a cathode. The organic compound layer includes at least a light-emitting layer and an electron injection layer. The light-emitting layer contains a light-emitting substance. The electron injection layer is a mixed layer of a first organic compound and a second organic compound. The first organic compound has strong basicity, and the second organic compound has electron-transporting properties. The ordinary light refractive index of the first organic compound with respect to any wavelength in the range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.80, and the ordinary light refractive index of the second organic compound with respect to any wavelength in the range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.75.

[0017] One embodiment of the present invention is a light-emitting device including an organic compound layer between an anode and a cathode. The organic compound layer includes at least a light-emitting layer and an electron injection layer. The light-emitting layer contains a light-emitting substance. The electron injection layer is a mixed layer of a first organic compound and a second organic compound. The first organic compound has strong basicity, and the second organic compound has electron-transporting properties. The ordinary light refractive index of the first organic compound with respect to the wavelength of 633 nm is 1.45 or more and less than 1.75, and the ordinary light refractive index of the second organic compound with respect to the wavelength of 633 nm is 1.45 or more and less than 1.70.

[0018] In the above light-emitting device, the first organic compound preferably has a guanidine skeleton.

[0019] One aspect of the present invention is a light-emitting device including an organic compound layer between an anode and a cathode. The organic compound layer includes at least a light-emitting layer and an electron injection layer. The light-emitting layer contains a light-emitting substance. The electron injection layer is a mixed layer of a first organic compound and a second organic compound. The first organic compound has a guanidine skeleton, and the second organic compound has electron-transporting properties. The ordinary light refractive index of the electron injection layer with respect to any wavelength in the range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.75.

[0020] One aspect of the present invention is a light-emitting device including an organic compound layer between an anode and a cathode. The organic compound layer includes at least a light-emitting layer and an electron injection layer. The light-emitting layer contains a light-emitting substance. The electron injection layer is a mixed layer of a first organic compound and a second organic compound. The first organic compound has a guanidine skeleton, and the second organic compound has electron-transporting properties. The ordinary light refractive index of the electron injection layer with respect to the wavelength of 633 nm is 1.45 or more and less than 1.70.

[0021] One aspect of the present invention is a light-emitting device including an organic compound layer between an anode and a cathode. The organic compound layer includes at least a light-emitting layer and an electron injection layer. The light-emitting layer contains a light-emitting substance. The electron injection layer is a mixed layer of a first organic compound and a second organic compound. The first organic compound has a guanidine skeleton, and the second organic compound has electron-transporting properties. The value obtained by adding the ordinary light refractive index of the first organic compound with respect to any wavelength in the range of 455 nm or more and 465 nm or less and dividing the sum by 2 with the ordinary light refractive index of the second organic compound with respect to any wavelength in the range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.75.

[0022] One aspect of the present invention is a light-emitting device including an organic compound layer between an anode and a cathode. The organic compound layer includes at least a light-emitting layer and an electron injection layer. The light-emitting layer contains a light-emitting substance. The electron injection layer is a mixed layer of a first organic compound and a second organic compound. The first organic compound has a guanidine skeleton, and the second organic compound has electron-transporting properties. The value obtained by adding the ordinary light refractive index of the first organic compound with respect to the wavelength of 633 nm and dividing the sum by 2 with the ordinary light refractive index of the second organic compound with respect to the wavelength of 633 nm is 1.45 or more and less than 1.70.

[0023] One embodiment of the present invention is a light-emitting device that includes an organic compound layer between an anode and a cathode. The organic compound layer includes at least a light-emitting layer and an electron injection layer. The light-emitting layer contains a light-emitting substance, and the electron injection layer is a mixed layer of a first organic compound and a second organic compound. The first organic compound has a guanidine skeleton, the second organic compound has electron-transporting properties, the ordinary light refractive index of the first organic compound with respect to any wavelength in the range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.80, and the ordinary light refractive index of the second organic compound with respect to any wavelength in the range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.75.

[0024] One embodiment of the present invention is a light-emitting device that includes an organic compound layer between an anode and a cathode. The organic compound layer includes at least a light-emitting layer and an electron injection layer. The light-emitting layer contains a light-emitting substance, and the electron injection layer is a mixed layer of a first organic compound and a second organic compound. The first organic compound has a guanidine skeleton, the second organic compound has electron-transporting properties, the ordinary light refractive index of the first organic compound with respect to a wavelength of 633 nm is 1.45 or more and less than 1.75, and the ordinary light refractive index of the second organic compound with respect to a wavelength of 633 nm is 1.45 or more and less than 1.70.

[0025] In the above light-emitting device, the first organic compound preferably has a 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine skeleton.

[0026] In the above light-emitting device, the first organic compound preferably exhibits a strong basicity with an acidity coefficient pKa of 8 or more.

[0027] In the above light-emitting device, the first organic compound preferably does not have an electron-transporting skeleton.

[0028] In the above light-emitting device, the ratio of the total number of carbon atoms in the molecule of the first organic compound that form bonds with sp 3 hybrid orbitals is preferably 10% or more and 60% or less.

[0029] In the above light-emitting device, the ratio of the total number of carbon atoms in the molecule of the second organic compound that form bonds with sp 3 hybrid orbitals is preferably 10% or more and 60% or less.

[0030] In the above light-emitting device, for the second organic compound 1 the integral value of the signal less than 4 ppm in the 1H-NMR measurement result is preferably larger than the integral value of the signal of 4 ppm or more.

[0031] In addition, another aspect of the present invention is a light-emitting device, which includes any of the above-described light-emitting elements and a transistor or a substrate.

[0032] Another aspect of the present invention is an electronic device, which includes any of the above-described light-emitting elements and a sensor, a speaker, or a microphone. Advantages of the Invention

[0033] According to one aspect of the present invention, a light-emitting element with high luminous efficiency can be provided. According to one aspect of the present invention, a light-emitting element with low power consumption can be provided. According to one aspect of the present invention, a light-emitting element with good reliability can be provided. According to one aspect of the present invention, a light-emitting element with high design freedom in the manufacturing process can be provided. According to one aspect of the present invention, a light-emitting element with high definition can be provided. According to one aspect of the present invention, a novel light-emitting element can be provided. According to one aspect of the present invention, a light-emitting device, an electronic device, a display device, and an electronic apparatus including the above-described light-emitting element can be provided.

[0034] Note that the description of these effects does not preclude the existence of other effects. Note that one aspect of the present invention does not necessarily have all of the above-described effects. Note that effects other than the above can be known and extracted from the descriptions in the specification, the drawings, the claims, and the like. Brief Description of the Drawings

[0035] Figure 1 is a view showing a light-emitting element. Figure 2A and Figure 2B is a band diagram showing the driving mechanism of the light-emitting element. Figure 3A and Figure 3B is a view showing a light-emitting element. Figure 4A and Figure 4B is a view showing a light-emitting element. Figure 5A and Figure 5B are a top view and a cross-sectional view of a light-emitting device. Figures 6A to 6D is a view showing a light-emitting element. Figures 7A to 7E is a cross-sectional view showing an example of a manufacturing method of a light-emitting device. Figures 8A to 8E is a cross-sectional view showing an example of a manufacturing method of a light-emitting device. Figures 9A to 9C is a cross-sectional view showing an example of a manufacturing method of a light-emitting device. Figures 10A to 10C is a cross-sectional view showing an example of a manufacturing method of a light-emitting device. Figures 11A to 11C It is a cross-sectional view showing an example of a method for manufacturing a light-emitting device. Figures 12A to 12C It is a cross-sectional view showing an example of a method for manufacturing a light-emitting device. Figures 13A to 13C It is a cross-sectional view showing an example of a method for manufacturing a light-emitting device. Figures 14A to 14G It is a top view showing an example of the structure of a pixel. Figures 15A to 15I It is a top view showing an example of the structure of a pixel. Figure 16A and Figure 16B It is a perspective view showing an example of the structure of a display module. Figure 17A and Figure 17B It is a cross-sectional view showing an example of the structure of a light-emitting device. Figure 18 It is a perspective view showing an example of the structure of a light-emitting device. Figure 19A It is a cross-sectional view showing an example of the structure of a light-emitting device. Figure 19B and Figure 19C It is a cross-sectional view showing an example of the structure of a transistor. Figure 20 It is a cross-sectional view showing an example of the structure of a light-emitting device. Figures 21A to 21D It is a cross-sectional view showing an example of the structure of a light-emitting device. Figures 22A to 22D It is a diagram showing an example of an electronic device. Figures 23A to 23F It is a diagram showing an example of an electronic device. Figures 24A to 24G It is a diagram showing an example of an electronic device. Figure 25 It is a diagram showing the measurement results of the refractive index according to an embodiment. Figure 26 It is a diagram showing the current efficiency-luminance characteristics of a sample according to an embodiment. Figure 27 It is a diagram showing the luminance-voltage characteristics of a sample according to an embodiment. Figure 28 It is a diagram showing the blue index (BI)-luminance characteristics of a sample according to an embodiment. Figure 29 It is a diagram showing the current density-voltage characteristics of a sample according to an embodiment. Figure 30 It is a diagram showing the external quantum efficiency-luminance characteristics of a sample according to an embodiment. Figure 31It is a diagram showing the luminance-current density characteristics of a sample according to an embodiment. Figure 32 It is a diagram showing the electroluminescence spectrum of a sample according to an embodiment. Figure 33 It is a diagram showing the normalized luminance-time change characteristics of a sample according to an embodiment. Mode for Carrying Out the Invention

[0036] The embodiments will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the following description, and it is easily understandable for those of ordinary skill in the art that its mode and details can be changed into various forms without departing from the gist and scope of the present invention. Therefore, the present invention should not be construed as being limited only to the content described in the following embodiments.

[0037] Note that in the structure of the invention described below, the same reference numerals are commonly used between different drawings to denote the same parts or parts having the same functions, and the repeated description thereof is omitted. In addition, when denoting parts having the same functions, the same hatching is sometimes used without particularly attaching reference numerals.

[0038] In addition, for ease of understanding, the positions, sizes, ranges, etc. of the respective components shown in the drawings do not necessarily represent their actual positions, sizes, ranges, etc. Therefore, the disclosed present invention is not necessarily limited to the positions, sizes, ranges, etc. disclosed in the drawings.

[0039] In the present specification and the like, a light-emitting device (also referred to as a light-emitting element) includes an EL layer between a pair of electrodes. The EL layer includes at least a light-emitting layer. In the present specification and the like, a light-receiving device (also referred to as a light-receiving element) includes at least an active layer serving as a photoelectric conversion layer between a pair of electrodes. In the present specification and the like, sometimes one of the pair of electrodes is denoted as a pixel electrode and the other is denoted as a common electrode.

[0040] Note that the light-emitting device in the present specification includes an image display device using an organic EL device. In addition, the light-emitting device sometimes further includes the following modules: a module in which an organic EL device is mounted with a connector such as an anisotropic conductive film or a TCP (Tape Carrier Package); a module in which a printed circuit board is provided at an end of the TCP; or a module in which an IC (integrated circuit) is directly mounted on the organic EL device by a COG (Chip On Glass) method. Furthermore, a lighting device or the like sometimes includes a light-emitting device.

[0041] Note that in the case where light is incident on a material having optical anisotropy, the light with a vibration plane parallel to the optical axis is called extraordinary light (ray), and the light with a vibration plane perpendicular to the optical axis is called ordinary light (ray). Sometimes, the refractive index of ordinary light and the refractive index of extraordinary light of this material are different. In this case, by performing anisotropy analysis, the refractive index of ordinary light and the refractive index of extraordinary light can be calculated separately. In this specification and the like, when the measured material has both the refractive index of ordinary light and the refractive index of extraordinary light, the refractive index of ordinary light is used as an index.

[0042] (Embodiment 1) An organic EL element (hereinafter also referred to as a light-emitting device) includes an organic compound layer containing a light-emitting substance between electrodes (between a first electrode and a second electrode), and emits light by the energy generated from the recombination of carriers (holes and electrons) injected into the organic compound layer from the electrodes.

[0043] Figure 1 A light-emitting device 130 showing one mode of the present invention is shown. The light-emitting device 130 is provided on an insulating layer 105. In addition, the light-emitting device 130 includes a first electrode 101 having an anode, a second electrode 102 having a cathode, and an organic compound layer 103 located between the first electrode 101 and the second electrode 102. The organic compound layer 103 includes a light-emitting layer 113 and an electron injection layer 115. Note that the organic compound layer is also referred to as an EL layer.

[0044] Here, as the electron injection layer 115, a mixed layer containing at least two or more organic compounds is preferably used, which contains a first organic compound having strong basicity and a second organic compound having electron transporting properties. Furthermore, preferably, the refractive index of ordinary light of this mixed layer with respect to any wavelength in the range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.75. More preferably, the refractive index of ordinary light of this mixed layer with respect to the entire wavelength range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.75. In addition, the refractive index of ordinary light of this mixed layer with respect to the wavelength of 633 nm is preferably 1.45 or more and less than 1.70.

[0045] The electron injection layer 115 using the above mixed layer is a layer with a low refractive index. By providing such a layer with a low refractive index inside the organic compound layer, the light extraction efficiency is improved, and thus a light-emitting device with high luminous efficiency can be obtained. The refractive index of the organic compound constituting the light-emitting device is generally about 1.8 to 1.9. A light-emitting device according to one mode of the present invention can achieve good luminous efficiency by including an electron injection layer with a low refractive index.

[0046] In particular, the electron injection layer 115 is provided between the light-emitting layer 113 and the second electrode 102 including a cathode, and thus is suitable for a top-emission type light-emitting device.

[0047] Here, the ordinary light refractive index of the first organic compound is set to n o1 , and the ordinary light refractive index of the second organic compound is set to n o2 . For example, the value obtained by adding n o1 and n o2 and dividing the sum by 2 is preferably within the above range so that the refractive index of the above mixed layer is within the above range. Specifically, the value obtained by adding n o1 with respect to any wavelength in the range of 455 nm or more and 465 nm or less and n o2 with respect to any wavelength in the range of 455 nm or more and 465 nm or less and dividing the sum by 2 is preferably 1.50 or more and less than 1.75. In addition, the value obtained by adding n o1 with respect to the wavelength of 633 nm and n o2 with respect to the wavelength of 633 nm and dividing the sum by 2 is preferably 1.45 or more and less than 1.70.

[0048] Note that when the value obtained by adding n o1 with respect to any wavelength in the range of 455 nm or more and 465 nm or less and n o2 and dividing the sum by 2 is 1.50 or more and less than 1.75 or the value obtained by adding n o1 with respect to the wavelength of 633 nm and n o2 and dividing the sum by 2 is 1.45 or more and less than 1.70, one or both of n o1 and n o2 may not be within the above range.

[0049] In addition, for example, one or both of n o1 and n o2 are preferably within the above range so that the refractive index of the above mixed layer is within the above range. Specifically, n o1 with respect to any wavelength in the range of 455 nm or more and 465 nm or less is preferably 1.50 or more and less than 1.80, more preferably 1.50 or more and less than 1.75. n o2 with respect to any wavelength in the range of 455 nm or more and 465 nm or less is preferably 1.50 or more and less than 1.80, more preferably 1.50 or more and less than 1.75. n o1 with respect to the wavelength of 633 nm is preferably 1.45 or more and less than 1.75, more preferably 1.45 or more and less than 1.70. n o2Preferably, it is 1.45 or more and less than 1.75, more preferably 1.45 or more and less than 1.70.

[0050] Note that in this specification and the like, an organic compound having a refractive index within the above range is sometimes referred to as a low refractive index organic compound. Further, an organic compound having a refractive index within the above range and having electron transporting properties is sometimes referred to as a low refractive index organic compound having electron transporting properties.

[0051] As described above, in one embodiment of the present invention, an organic compound having a large acidity coefficient (pKa) and strong basicity is used as the first organic compound. In this case, after holes injected from the first electrode 101 (anode) side are captured or blocked by the organic compound having strong basicity, electrons are injected from the electron injection layer 115, whereby the light emitting device 130 is driven.

[0052] Note that the reason why the organic compound having strong basicity blocks holes is that a material having a large pKa has a large dipole moment. By the interaction between this dipole moment and holes, the electron injection layer 115 can block holes.

[0053] In addition, the organic compound having strong basicity has high nucleophilicity. That is, a material having high nucleophilicity sometimes reacts with a molecule that receives a hole and becomes a cation radical to generate a new molecule or an intermediate state. Sometimes this reaction consumes holes and the hole transporting property in the electron injection layer 115 is greatly reduced.

[0054] In addition, when holes and electrons are respectively injected into the highest occupied molecular orbital (HOMO) energy level and the lowest unoccupied molecular orbital (LUMO) energy level of the organic compound having strong basicity, carriers are recombined and an unstable excited state is easily formed, so the reliability decreases and the characteristics as a light emitting device deteriorate.

[0055] Then, by mixing a second organic compound having electron transporting properties into the electron injection layer 115 using the first organic compound having strong basicity, molecules that capture or block holes can be separated from molecules that conduct electrons. Thereby, the recombination probability of carriers in the electron injection layer 115 can be reduced and the formation of an unstable excited state can be suppressed, so the reliability of the light emitting device is improved. That is, when the mixed layer for the electron injection layer 115 contains the first organic compound for capturing holes and the second organic compound for transporting electrons, the formation of an unstable excited state is suppressed and the reliability of the light emitting device is improved.

[0056] Therefore, as the second organic compound having electron-transporting properties, an organic compound having a LUMO level lower than that of the first organic compound having strong basicity is preferably used. In addition, as the second organic compound having electron-transporting properties, an organic compound having a HOMO level lower than that of the first organic compound having strong basicity is preferably used.

[0057] In other words, the LUMO level of the first organic compound is preferably higher than that of the second organic compound. For example, as the first organic compound, an organic compound having a LUMO level higher than that of the second organic compound by 0.05 eV or more, preferably 0.1 eV or more, and more preferably 0.2 eV or more is preferably used. By adopting such a structure, the probability that the first organic compound accepts electrons under the influence of energy at room temperature, an electric field, or the like can be reduced.

[0058] In addition, as the first organic compound, an organic compound having a HOMO level higher than that of the second organic compound by 0.05 eV or more, preferably 0.1 eV or more, and more preferably 0.2 eV or more is preferably used. By adopting such a structure, the probability that the second organic compound accepts holes under the influence of energy at room temperature, an electric field, or the like can be reduced.

[0059] The thicker the electron injection layer 115 is, the greater the distance between the holes accumulated in the electron injection layer 115 and the electrons accumulated in the electrode becomes, and sometimes the electric field of the double layer is relaxed and the voltage of the manufactured light-emitting device increases. For example, the thickness of the electron injection layer 115 is preferably 2 nm or more and 13 nm or less, and more preferably 5 nm or more and 10 nm or less.

[0060] In addition, in order to obtain an effect of improving the light extraction efficiency by providing a layer having a low refractive index, the layer having a low refractive index is preferably thick. For example, the thickness of the electron injection layer 115 is preferably 10 nm or more and 50 nm or less, and more preferably 15 nm or more and 35 nm or less.

[0061] Note that the thickness of the electron injection layer 115 is preferably set within the above range to suppress an increase in the voltage of the light-emitting device and achieve a high-efficiency effect.

[0062] In addition, by using the first organic compound having a low refractive index and strong basicity and the second organic compound having a low refractive index and electron-transporting properties for the electron injection layer 115, the light extraction efficiency can be improved and the luminous efficiency of the light-emitting device can be improved, and the electron injection property can also be improved. Therefore, the driving voltage of the light-emitting device can be reduced and the power consumption can be reduced. In addition, although the driving voltage of the light-emitting device sometimes increases when using an organic compound having a low refractive index, by combining with an organic compound having strong basicity, an increase in the driving voltage can be suppressed, and thus a light-emitting device having low power consumption can be manufactured.

[0063] <First organic compound> The LUMO energy level of the first organic compound is preferably -2.50 eV or more and -1.00 eV or less. In addition, the HOMO energy level of the first organic compound is preferably -5.7 eV or more and -4.8 eV or less.

[0064] In addition, the first organic compound preferably does not include a skeleton having electron-transporting properties. For example, as the first organic compound, there is an organic compound in which the aromatic ring does not contain a nitrogen atom (N).

[0065] In addition, the first organic compound is preferably a strongly basic organic compound having an acidity coefficient pKa of 8 or more. By including a strongly basic organic compound having an acidity coefficient pKa of 8 or more, the first organic compound can block holes and accumulate holes in the electron injection layer.

[0066] Preferably, the first organic compound is an organic compound having an acidity coefficient pKa of 8 or more, preferably an organic compound having an acidity coefficient pKa greater than 10. In addition, more preferably, the first organic compound is an organic compound having an acidity coefficient pKa of 12 or more, preferably an organic compound having an acidity coefficient pKa greater than 13.

[0067] As the acidity coefficient pKa of the basic skeleton, the value of an organic compound in which a part of the skeleton is replaced by hydrogen can be used. In addition, as the acidity index of an organic compound having a basic skeleton, the acidity coefficient pKa of the basic skeleton can be used. In addition, when the organic compound has a plurality of basic skeletons, the acidity coefficient pKa of the basic skeleton having the largest acidity coefficient pKa can be used as the acidity index of the organic compound.

[0068] Alternatively, the acidity coefficient pKa of the organic compound can also be obtained by the following calculation.

[0069] First, the initial structure of the molecular structure of each molecule as the calculation model is the most stable structure (singlet ground state) obtained by first-principles calculation.

[0070] As the above first-principles calculation, use Jaguar of quantum chemistry calculation software manufactured by Inc., and calculate the most stable structure in the singlet ground state by density functional theory (DFT: Density Functional Theory). Use 6-31G** as the basis function and B3LYP-D3 as the functional. As the structure for performing quantum chemistry calculation, use Maestro GUI manufactured by Inc., and perform conformational analysis by Mixed torsional / Low-mode sampling for sampling.

[0071] In pKa calculation, more than one atom in each molecule was designated as a basic site. MacroModel was used to explore the structures of protonated molecules stable in water, and the conformational isomer with the lowest energy obtained from conformational exploration using the OPLS2005 force field was used. Using the pKa calculation module of Jaguar, its structure was optimized with B3LYP / 6-31G*, and then a single-point calculation was performed with cc-pVTZ(+). The pKa value was calculated using empirical correction for functional groups. In the molecule where more than one atom was designated as a basic site, the largest value among the obtained results was used as the pKa value.

[0072] As specific examples of organic compounds with a large acid dissociation constant pKa, organic compounds having a basic skeleton represented by the following structural formulas (120) to (123) can be cited.

[0073] [Chemical formula 1]

[0074] Furthermore, preferably, the above-mentioned organic compound with a pKa of 8 or more is specifically an organic compound having a bicyclic structure with two or more nitrogens in the ring-forming atoms, a heteroaromatic ring with 2 to 30 ring-forming carbon atoms, or an aromatic ring with 6 to 30 ring-forming carbon atoms, and more specifically an organic compound having a 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine skeleton, a heteroaromatic ring with 2 to 30 ring-forming carbon atoms, or an aromatic ring with 6 to 30 ring-forming carbon atoms. More preferably, the above-mentioned organic compound is an organic compound having a bicyclic structure with two or more nitrogens in the ring-forming atoms and a heteroaromatic ring with 2 to 30 ring-forming carbon atoms, and more specifically an organic compound having a 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine skeleton and a heteroaromatic ring with 2 to 30 ring-forming carbon atoms. In addition, an organic compound having a guanidine skeleton is preferred.

[0075] More specifically, preferably, it is an organic compound represented by the following general formula (G1).

[0076] [Chemical formula 2]

[0077] In the organic compound represented by the above general formula (G1), X represents a group represented by the following general formula (G1-1), and Y represents a group represented by the following general formula (G1-2). In addition, R 1 and R 2Each independently represents hydrogen or deuterium, h represents an integer from 1 to 6, and Ar represents a substituted or unsubstituted heteroaromatic ring having 2 to 30 ring carbon atoms or a substituted or unsubstituted aromatic ring having 6 to 30 ring carbon atoms. Note that Ar is preferably a substituted or unsubstituted heteroaromatic ring having 2 to 30 ring carbon atoms.

[0078] [Chemical formula 3]

[0079] In the above general formulas (G1-1) and (G1-2), R 3 to R 6 Each independently represents hydrogen or deuterium, m represents an integer from 0 to 4, n represents an integer from 1 to 5, and m + 1 ≥ n. When m or n is 2 or more, the plurality of R 3 to R 6 may also be the same as or different from each other.

[0080] In addition, the organic compound represented by the above general formula (G1) is preferably represented by any one of the following general formulas (G2-1) to (G2-6).

[0081] [Chemical formula 4]

[0082] Note that R 11 to R 26 Each independently represents hydrogen or deuterium, h represents an integer from 1 to 6, and Ar represents a substituted or unsubstituted heteroaromatic ring having 2 to 30 ring carbon atoms or a substituted or unsubstituted aromatic ring having 6 to 30 ring carbon atoms. Note that Ar is preferably a substituted or unsubstituted heteroaromatic ring having 2 to 30 ring carbon atoms.

[0083] As the substituted or unsubstituted heteroaromatic ring having 2 to 30 ring-constituting carbon atoms or the aromatic ring having 6 to 30 ring-constituting carbon atoms represented by Ar in the above general formula (G1) and general formulas (G2-1) to (G2-6), specifically, a pyridine ring, bipyridine ring, pyrimidine ring, bipyrimidine ring, pyrazine ring, bipyrazine ring, triazine ring, quinoline ring, isoquinoline ring, benzoquinoline ring, phenanthroline ring, quinoxaline ring, benzoquinoxaline ring, dibenzoquinoxaline ring, azafluorene ring, diazafluorene ring, carbazole ring, benzocarbazole ring, dibenzocarbazole ring, dibenzofuran ring, benzonaphthofuran ring, dinaphthofuran ring, dibenzothiophene ring, benzonaphthothiophene ring, dinaphthothiophene ring, benzofuranopyridine ring, benzofuranopyrimidine ring, benzothiophenopyridine ring, benzothiophenopyrimidine ring, naphthofuranopyridine ring, naphthofuranopyrimidine ring, naphthothiophenopyridine ring, naphthothiophenopyrimidine ring, acridine ring, xanthene ring, phenothiazine ring, phenoxazine ring, phenazine ring, triazole ring, oxazole ring, oxadiazole ring, thiazole ring, thiadiazole ring, imidazole ring, benzimidazole ring, pyrazole ring, pyrrole ring, etc. can be mentioned. In addition, in the above general formula (G1) and general formulas (G2-1) to (G2-6), as the substituted or unsubstituted aromatic ring having 6 to 30 ring-constituting carbon atoms represented by Ar, specifically, a benzene ring, naphthalene ring, fluorene ring, dimethylfluorene ring, diphenylfluorene ring, spirofluorene ring, anthracene ring, phenanthrene ring, triphenylene ring, pyrene ring, tetracene ring, ring, benzo[a]anthracene ring, etc. are particularly preferably any one of the following structural formulas (Ar-1) to (Ar-27).

[0084] [Chemical formula 5]

[0085] Note that the above Ar contains nitrogen as a ring-constituting atom, and this Ar is preferably bonded to the skeleton within the parentheses in the above general formula (G1) by a bond of this nitrogen or a carbon adjacent to this nitrogen.

[0086] As specific examples of the organic compounds represented by the above general formula (G1) and general formulas (G2-1) to (G2-6), 1,1'-(9,9'-spirobi[9H-fluorene]-2,7-diyl)bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) (abbreviation: 2,7hpp2SF) represented by the following (Structural formula 108) and 1-(9,9'-spirobi[9H-fluorene]-2-yl)-1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (abbreviation: 2hppSF) represented by the following (Structural formula 109) and other organic compounds represented by the following structural formulas (101) to (117) can be cited. Among them, organic compounds having a spirofluorene skeleton such as the following structural formulas (106) to (109) or organic compounds having a single hexahydropyrimidopyrimidine skeleton such as the following structural formulas (102), (104), (105), (109), (110), and (115) are preferably used, and the organic compound represented by the following structural formula (109) is particularly preferably used.

[0087] [Chemical formula 6]

[0088] Note that, from the viewpoint of suppressing the recombination of the injected electrons and the blocked holes on a strongly basic substance having an acidity coefficient pKa of 8 or more, it is preferable that the strongly basic substance having an acidity coefficient pKa of 8 or more does not have an electron transport skeleton. As the strongly basic substance having an acidity coefficient pKa of 8 or more, specifically, 1-(9,9'-spirobi[9H-fluorene]-2-yl)-1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (abbreviation: 2hppSF), 1,1'-(9,9'-spirobi[9H-fluorene]-2,7-diyl)bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) (abbreviation: 2,7hpp2SF), 1-(2',7'-di-tert-butyl-9,9'-spirobi[9H-fluorene]-2-yl)-1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (abbreviation: 2',7'tBu-2hppSF), 1,1'-pyridine-2,6-diyl-bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) (abbreviation: hpp2Py), 2,9-bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidin-1-yl)-1,10-phenanthroline (abbreviation: 2,9hpp2Phen), 4,7-di-1-pyrrolidinyl-1,10-phenanthroline (abbreviation: Pyrrd-Phen), or 8,8'-pyridine-2,6-diyl-bis(5,6,7,8-tetrahydroimidazo[1,2-a]pyrimidine) (abbreviation: 2,6tip2Py) and other organic compounds can be used. Specifically, for example, the pKa of 2hppSF is 13.95, the pKa of 2,7hpp2SF is 14.83, the pKa of 2',7'tBu-2hppSF is 14.18, the pKa of hpp2Py is 14.41, the pKa of 2,9hpp2Phen is 13.35, the pKa of Pyrrd-Phen is 11.23, and the pKa of 2,6tip2Py is 9.58.

[0089] In addition, in the case of manufacturing a light-emitting device by a process including a washing step such as atmospheric exposure or using an aqueous solution, it is preferable that the solubility of the first organic compound is low. For example, the solubility of the first organic compound is affected by the number of hydrophilic groups such as the hpp group and the number of hydrophobic groups such as the tert-butyl group in the first organic compound. Therefore, the fewer the number of hydrophilic groups in the first organic compound, the better, and preferably 1. In addition, the number of hydrophobic groups in the first organic compound is preferably larger than the number of hydrophilic groups, and specifically preferably 2 or more.

[0090] Specifically, the solubility of the first organic compound in water is preferably less than 0.77 mg / ml, more preferably 0.065 mg / ml or less, still more preferably 0.0023 mg / ml or less, and even more preferably 1×10 -5 mg / ml or less.

[0091] Specifically, for example, the solubility of 1,1'-(9,9'-spirobi[9H-fluorene]-2,7-diyl)bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) (abbreviation: 2,7hpp2SF) represented by the structural formula (108) is 0.23 mg / ml or more and less than 0.39 mg / ml, the solubility of 1-(9,9'-spirobi[9H-fluorene]-2-yl)-1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (abbreviation: 2hppSF) represented by the structural formula (109) is 0.018 mg / ml or more and less than 0.022 mg / ml, the solubility of 1,1'-(2',7'-tert-butyl-9,9'-spirobi[9H-fluorene]-2,7-diyl)bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) (abbreviation: 2',7'tBu-2,7hpp2SF) is 0.058 mg / ml or more and less than 0.065 mg / ml, and the solubility of 1-(2',7'-di-tert-butyl-9,9'-spirobi[9H-fluorene]-2-yl)-1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (abbreviation: 2',7'tBu-2hppSF) is less than 0.0023 mg / ml. Since its solubility is low, it is preferred.

[0092] In addition, even when a first organic compound with high solubility is added, a light-emitting device without defects can be provided by adjusting the concentration of the first organic compound in the electron injection layer 115. Specifically, when the concentration (wt%) of the first organic compound in the electron injection layer 115 is y and the solubility of the first organic compound in water (mg / ml) is x, it is preferably below the value of y = -8.735×ln(x) - 2.3154.

[0093] In addition, the above-mentioned organic compounds with strong basicity or high pKa (for example, organic compounds with a basic skeleton represented by the above structural formulas (120) to (123); organic compounds with a bicyclic structure having two or more nitrogens as ring-forming atoms, a heteroaromatic ring with 2 to 30 ring-forming carbon atoms, or an aromatic ring with 6 to 30 ring-forming carbon atoms; organic compounds with a 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine skeleton, a heteroaromatic ring with 2 to 30 ring-forming carbon atoms, or an aromatic ring with 6 to 30 ring-forming carbon atoms; organic compounds with a guanidine skeleton) include multiple hydrocarbon groups bonded by sp 3 hybrid orbitals, so they have a low refractive index. By using this organic compound in the electron injection layer, the light extraction efficiency of the light-emitting device can be improved.

[0094] In addition, in such an organic compound, the ratio of the total number of carbon atoms bonded by sp 3 hybrid orbitals to the total number of carbon atoms in the molecule is preferably 10% or more and 60% or less, more preferably 10% or more and 50% or less. Specifically, for example, as the ratio of the total number of carbon atoms bonded by sp 3 hybrid orbitals to the total number of carbon atoms in the molecule of the organic compound, 2hppSF is 22%, 2,7hpp2SF is 33%, 2’,7’tBu-2hppSF is 38%, 2,9hpp2Phen is 46%, Pyrrd-Phen is 40%, and 2,6tip2Py is 35%.

[0095] In addition, the first organic compound is preferably an organic compound with a low refractive index and strong basicity. Specifically, as such an organic compound, for example, it is preferably an organic compound having an ordinary light refractive index of 1.50 or more and less than 1.80 and strong basicity with respect to any wavelength in the range of 455 nm or more and 465 nm or less, and more preferably an organic compound having an ordinary light refractive index of 1.50 or more and less than 1.80 and strong basicity with respect to the entire wavelength range of 455 nm or more and 465 nm or less. Alternatively, as an organic compound with a low refractive index and strong basicity, it is preferably an organic compound having an ordinary light refractive index of 1.45 or more and less than 1.75 and strong basicity with respect to any wavelength in the range of 500 nm or more and 650 nm or less, and more preferably an organic compound having an ordinary light refractive index of 1.45 or more and less than 1.75 and strong basicity with respect to the entire wavelength range of 500 nm or more and 650 nm or less.

[0096] <Second Organic Compound> On the other hand, the second organic compound is a low refractive index organic compound having electron transporting properties. As the low refractive index organic compound having electron transporting properties, preferably, the ordinary light refractive index with respect to any wavelength in the range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.75 and has electron transporting properties. More preferably, the ordinary light refractive index with respect to the entire wavelength range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.75 and has electron transporting properties. In addition, as the low refractive index organic compound having electron transporting properties, preferably, the ordinary light refractive index with respect to any wavelength in the range of 500 nm or more and 650 nm or less is 1.45 or more and less than 1.70 and has electron transporting properties. More preferably, the ordinary light refractive index with respect to the entire wavelength range of 500 nm or more and 650 nm or less is 1.45 or more and less than 1.70 and has electron transporting properties.

[0097] As the organic compound having electron transporting properties and a refractive index within the above range, for example, the following substances can be cited. Note that in addition to the following substances, as long as the square root of the electric field strength [V / cm] is 600, the electron mobility is 1×10 -7 cm 2 / Vs or more, preferably 1×10 -6 cm 2 / Vs or more and a substance that can form a film with a refractive index within the above range can be used in the same manner.

[0098] As the low refractive index organic compound having electron transporting properties, there can be cited those having at least one six-membered ring heteroaromatic ring with 1 to 3 nitrogen atoms, including a plurality of condensed aromatic hydrocarbon rings with 6 to 14 ring-forming carbon atoms, at least two of the plurality of the condensed aromatic hydrocarbon rings being benzene rings, and including a plurality of hydrocarbon groups bonded by sp 3 hybrid orbitals.

[0099] In addition, in such an organic compound, the ratio of the total number of carbon atoms in the molecule bonded by sp 3 hybrid orbitals to the total number of carbon atoms is preferably 10% or more and 60% or less, more preferably 10% or more and 50% or less. Alternatively, in such an organic compound, in the result of measuring the organic compound using 1 H-NMR, the integral value of the signal less than 4 ppm is preferably 1 / 2 times or more of the integral value of the signal of 4 ppm or more.

[0100] Preferably, the molecular weight of the above-mentioned organic compound having electron transporting properties is preferably 500 or more and 2000 or less. In addition, all of the sp 3A hydrocarbon group formed by hybrid orbitals to form a bond is bonded to the above-mentioned fused aromatic hydrocarbon ring having 6 to 14 ring-forming carbon atoms.

[0101] The organic compound having electron transporting properties is preferably an organic compound represented by the following general formula (G e1 1) or (G e1 1-1).

[0102] [Chemical formula 7]

[0103] In the general formula, A represents a six-membered heteroaromatic ring having 1 or more and 3 or less nitrogen atoms, and is preferably a pyridine ring, a pyrimidine ring, a pyrazine ring, a pyridazine ring, or a triazine ring.

[0104] In addition, R 200 represents hydrogen, an alkyl group having 1 to 6 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, or a substituent represented by the above general formula (G e1 1-1).

[0105] In addition, at least one of R 201 to R 215 is a phenyl group having a substituent, and the others each independently represent any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 14 ring-forming carbon atoms, or a substituted or unsubstituted pyridyl group. R 201 , R 203 , R 205 , R 206 , R 208 , R 210 , R 211 , R 213 and R 215 are all preferably hydrogen. The above-mentioned phenyl group having a substituent has one or two substituents, and the substituents are each independently an alkyl group having 1 to 6 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 14 ring-forming carbon atoms.

[0106] The organic compound represented by the above general formula (G e1 1) has a plurality of hydrocarbon groups selected from alkyl groups having 1 to 6 carbon atoms and alicyclic groups having 3 to 10 carbon atoms, and the ratio of the total number of carbon atoms bonded by sp 3 hybrid orbitals in the total number of carbon atoms in the molecule is 10% or more and 60% or less.

[0107] In addition, as the organic compound having electron transporting properties, an organic compound represented by the following general formula (G e1 2) is preferably used.

[0108] [Chemical Formula 8]

[0109] In the general formula, two or three of Q 1 to Q 3 represent N. Note that in the general formula, when two of Q 1 to Q 3 are N, the remaining one represents CH.

[0110] In addition, at least any one of R 201 to R 215 is a phenyl group having a substituent, and the others each independently represent hydrogen, an alkyl group having 1 to 6 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 14 ring-constituting carbon atoms, or a substituted or unsubstituted pyridyl group, a substituent containing any one of a pyridyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, and a triazinyl group. R 201 , R 203 , R 205 , R 206 , R 208 , R 210 , R 211 , R 213 and R 215 are all preferably hydrogen. The above-mentioned phenyl group having a substituent has one or two substituents, and the substituents are each independently an alkyl group having 1 to 6 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 14 ring-constituting carbon atoms.

[0111] The organic compound represented by the above general formula (G e1 2) has a plurality of hydrocarbon groups selected from an alkyl group having 1 to 6 carbon atoms and an alicyclic group having 3 to 10 carbon atoms, and the ratio of the total number of carbon atoms bonded by sp 3 hybrid orbitals in the total number of carbon atoms in the molecule is preferably 10% or more and 60% or less.

[0112] In addition, in the organic compound represented by the above general formula (G e1 1) or (G e1 2), the phenyl group having a substituent is preferably a group represented by the following formula (G e1 1-2).

[0113] [Chemical Formula 9]

[0114] In the general formula, α represents a substituted or unsubstituted phenylene group, and a meta-substituted phenylene group is preferred. Additionally, when the meta-substituted phenylene group has one substituent, it is preferred that this substituent is also meta-substituted. The substituent is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic group having 3 to 10 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, and further preferably a tert-butyl group.

[0115] R 220 represents an alkyl group having 1 to 6 carbon atoms, an alicyclic group having 3 to 10 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 14 ring carbon atoms.

[0116] In addition, j and k represent 1 or 2. Note that when j is 2, the multiple α's can be the same or different. Additionally, when k is 2, the multiple R 220 's can be the same as or different from each other. R 220 is preferably a phenyl group, more preferably a phenyl group having an alkyl group having 1 to 6 carbon atoms or an alicyclic group having 3 to 10 carbon atoms at one or both of the two meta-positions. The substituent that the phenyl group has at one or both of the two meta-positions is more preferably an alkyl group having 1 to 6 carbon atoms, and further preferably a tert-butyl group.

[0117] As the organic compound represented by the above general formula (G e1 2), specifically, 2-{(3',5'-di-tert-butyl)biphenyl-3-yl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mmtBumBPTzn), 2-(3,3",5,5"-tetra-tert-butyl-1,1':3',1"-terphenyl-5'-yl)-4,6-diphenyl-1,3,5-triazine (abbreviation: mmtBumTPTzn), 2-(3,3",5',5"-tetra-tert-butyl-1,1':3',1"-terphenyl-5-yl)-4,6-diphenyl-1,3,5-triazine (abbreviation: mmtBumTPTzn-02), 2-{(3',5'-di-tert-butyl)biphenyl-3-yl}-4,6-bis(3,5-di-tert-butylphenyl)-1,3,5-triazine (abbreviation: mmtBumBP-dmmtBuPTzn), 2-{3-[(3,5-di-tert-butyl)phenyl]-5-(pyrimidin-5-yl)phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mmtBuPh-mPmPTzn), 2-{3-[(3,5-di-tert-butyl)phenyl]-5-(pyrazin-2-yl)phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mmtBuPh-mPrPTzn) and other organic compounds can be cited.

[0118] By co-evaporating the organic compound described in <First Organic Compound> and the organic compound described in <Second Organic Compound>, a mixed layer can be formed. By using this mixed layer as an electron injection layer for the intermediate layer, the luminous efficiency of the light-emitting device can be improved.

[0119] For this reason, as the mixed layer of the first organic compound and the second organic compound, preferably, the ordinary light refractive index with respect to any wavelength in the range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.75, and more preferably, the ordinary light refractive index with respect to the entire wavelength range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.75. Alternatively, as the mixed layer of the first organic compound and the second organic compound, preferably, the ordinary light refractive index with respect to any wavelength in the range of 500 nm or more and 650 nm or less is preferably 1.45 or more and less than 1.70, and more preferably, the ordinary light refractive index with respect to the entire wavelength range of 500 nm or more and 650 nm or less is 1.45 or more and less than 1.70.

[0120] In addition, the value obtained by adding the ordinary light refractive index of the first organic compound with respect to any wavelength in the range of 455 nm or more and 465 nm or less and dividing by 2 the ordinary light refractive index of the second organic compound with respect to any wavelength in the range of 455 nm or more and 465 nm or less is preferably 1.50 or more and less than 1.75. Alternatively, the value obtained by adding the ordinary light refractive index of the first organic compound with respect to any wavelength in the range of 500 nm or more and 650 nm or less and dividing by 2 the ordinary light refractive index of the second organic compound with respect to any wavelength in the range of 500 nm or more and 650 nm or less is preferably 1.45 or more and less than 1.70.

[0121] <Structure of the Light-Emitting Device> The following describes the specific structure other than the above structure of the light-emitting device 130 including the above organic compound.

[0122] [Electrode] The following describes the structures of the first electrode 101 and the second electrode 102.

[0123] The first electrode 101 is an electrode including an anode. The first electrode 101 may also have a laminated structure, in which case the layer in contact with the organic compound layer 103 is used as the anode. The anode is preferably formed of a metal, alloy, conductive compound, and a mixture thereof having a large work function (specifically, 4.0 eV or more). Specifically, for example, indium tin oxide (ITO), indium tin oxide containing silicon or silicon oxide, indium zinc oxide, indium oxide containing tungsten oxide and zinc oxide (IWZO), etc. can be cited. Although these conductive metal oxide films are usually deposited by a sputtering method, a sol-gel method or the like can also be applied to form them. As an example of the forming method, a method of forming indium zinc oxide by sputtering using a target in which 1 wt% to 20 wt% of zinc oxide is added to indium oxide can be cited. In addition, indium oxide containing tungsten oxide and zinc oxide (IWZO) can be formed by sputtering using a target in which 0.5 wt% to 5 wt% of tungsten oxide and 0.1 wt% to 1 wt% of zinc oxide are added to indium oxide. In addition, as materials for the anode, for example, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), or nitrides of metal materials (for example, titanium nitride) can be cited. In addition, graphene can also be used as a material for the anode. In addition, by using the composite material described later for the layer in contact with the anode (typically, the hole injection layer), it is not necessary to consider the work function when selecting the electrode material.

[0124] The second electrode 102 is an electrode including a cathode. The second electrode 102 may also have a laminated structure, in which case the layer in contact with the organic compound layer 103 is used as the cathode. As the material for forming the cathode, a metal, alloy, conductive compound, and a mixture thereof having a small work function (specifically, 3.8 eV or less) can be used. As specific examples of such cathode materials, alkali metals such as lithium (Li) or cesium (Cs), elements belonging to Group 1 or Group 2 of the periodic table such as magnesium (Mg), calcium (Ca), strontium (Sr), alloys containing them (MgAg, AlLi), rare earth metals such as europium (Eu), ytterbium (Yb), and alloys containing them can be cited. However, by providing an electron injection layer between the second electrode 102 and the electron transport layer, various conductive materials such as Al, Ag, ITO, indium tin oxide containing silicon or silicon oxide, etc. can be used as the cathode regardless of the size of the work function.

[0125] In addition, when the second electrode 102 is made of a material having transparency to visible light, a light-emitting device that emits light from the second electrode 102 side can be formed.

[0126] These conductive materials can be deposited by dry methods such as vacuum evaporation and sputtering, or by deposition methods such as inkjet printing and spin coating. In addition, they can also be formed by wet methods such as the sol-gel method or by using pastes of metal materials.

[0127] [Organic compound layer] The structure of the organic compound layer 103 will be described below.

[0128] In addition to the light-emitting layer 113 and the electron injection layer 115, the organic compound layer 103 may also include other functional layers. Figure 1 The structure is shown in which a hole injection layer 111, a hole transport layer 112, and an electron transport layer 114 are provided in the organic compound layer 103 in addition to the light-emitting layer 113 and the electron injection layer 115. At this time, the organic compound layer 103 has a stacked structure. In Figure 1 a structure including a hole injection layer 111, a hole transport layer 112, a light-emitting layer 113, an electron transport layer, and an electron injection layer 115 is shown as this stacked structure. Note that the structure of the organic compound layer 103 of the present invention is not limited to this, and any layer may not be provided, or other layers may be provided. As other layers, typically there are carrier blocking layers (hole blocking layer, electron blocking layer), exciton blocking layers, intermediate layers, etc.

[0129] In addition, although Figure 1 an example is shown in which the first electrode 101 is formed on one side of the insulating layer 105, a so-called reverse stacked structure in which the second electrode 102 is formed on one side of the insulating layer 105 may also be employed. At this time, the light-emitting device has a stacked structure in which, from one side of the insulating layer 105, there are the second electrode 102, the electron injection layer 115, the electron transport layer 114, the light-emitting layer 113, the hole transport layer 112, the hole injection layer 111, and the first electrode 101. When a light-emitting device having this reverse stacked structure is used, the relatively stable hole injection layer 111 becomes the surface, and thus a more reliable light-emitting device can be realized.

[0130] As described above, the electron injection layer 115 is a layer containing a first organic compound having a basic skeleton and a second organic compound having electron transporting properties. Any one or more of metals, metal compounds, and metal complexes may also be mixed in this layer.

[0131] In addition, the first organic compound having a basic skeleton in the electron injection layer 115 preferably does not have an electron donating property. Further, the first organic compound having a basic property preferably does not have an electron donating property with respect to the second organic compound having an electron transporting property. When the first organic compound having a basic property has an electron donating property, it is more likely to react with atmospheric components such as water or oxygen, so the stability decreases. By including the first organic compound having a basic property and the second organic compound having an electron transporting property, the hole transporting property of the electron injection layer 115 can be significantly reduced. Therefore, even if the first organic compound having a basic property does not have an electron donating property, it can be used as an electron injection layer. Thus, a light-emitting device stable to atmospheric components such as water or oxygen can be manufactured. Further, in the electron injection layer 115, preferably, the signal observed by electron spin resonance (ESR: Electron Spin Resonance) is small or no signal is observed. For example, the spin density due to the signal observed near a g value of 2.00 is preferably 1×10 17 spins / cm 3 Hereinafter, it is more preferably less than 1×10 16 spins / cm 3 .

[0132] The hole injection layer 111 is in contact with the anode and has a function of facilitating injection of holes into the organic compound layer 103. Phthalocyanine compounds such as phthalocyanine (abbreviation: H2Pc), phthalocyanine complex compounds such as copper phthalocyanine (CuPc), etc. can be used; aromatic amine compounds such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), etc.; or polymers such as poly(3,4-ethylenedioxythiophene) / (polystyrenesulfonic acid) (abbreviation: PEDOT / PSS) can be used to form the hole injection layer 111.

[0133] In addition, the hole injection layer 111 can also be formed using a material having an electron acceptor property. As the material having an acceptor property, an organic compound having an electron-withdrawing group (halogen group, cyano group, etc.) can be used. Examples include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloroquinone, 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-pyrene-2-ylidene) malononitrile, etc. In particular, compounds such as HAT-CN in which an electron-withdrawing group is bonded to a fused aromatic ring having multiple heteroatoms are thermally stable and thus preferred. In addition, [3]axylene derivatives including an electron-withdrawing group (especially a halogen group such as a fluorine group, a cyano group) have a very high electron-accepting property and are particularly preferred. Specifically, examples include α,α',α''-1,2,3-cyclopropanetriylidene tris[4-cyano-2,3,5,6-tetrafluorobenzyl cyanide], α,α',α''-1,2,3-cyclopropanetriylidene tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzyl cyanide], α,α',α''-1,2,3-cyclopropanetriylidene tris[2,3,4,5,6-pentafluorobenzyl cyanide], etc. As the material having an acceptor property, in addition to the above organic compounds, transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, manganese oxide, etc. can also be used.

[0134] In addition, the hole injection layer 111 can also be formed using a composite material containing a material having an acceptor property and an organic compound having a hole-transporting property in the same manner. The material having an acceptor property preferably has an electron-accepting property with respect to the organic compound having a hole-transporting property. As the material having an acceptor property, the materials cited above can be used.

[0135] As the organic compound having a hole-transporting property for the composite material, various organic compounds such as aromatic amine compounds, heteroaromatic compounds, aromatic hydrocarbons, polymer compounds (oligomers, dendrimers, polymers, etc.) can be used. As the organic compound having a hole-transporting property for the composite material, it is preferably used with a hole mobility of 1×10 -6 cm 2An organic compound of more than / Vs. The organic compound having hole transporting properties for a composite material is preferably a compound containing a fused aromatic ring or a π-electron rich heteroaromatic ring. As the fused aromatic ring, an anthracene ring, a naphthalene ring, etc. are preferred. In addition, as the π-electron rich heteroaromatic ring, a fused aromatic ring containing at least one of a pyrrole skeleton, a furan skeleton, and a thiophene skeleton is preferred, and specifically, a carbazole ring, a dibenzothiophene ring, or a ring in which these rings are further fused with an aromatic ring or a heteroaromatic ring is preferred.

[0136] Such an organic compound having hole transporting properties more preferably has any one of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton. In particular, it can be an aromatic amine having a substituent including a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine including a naphthalene ring, or an aromatic monoamine in which 9-fluorenyl is bonded to the nitrogen of the amine through an arylene group. Note that when these organic compounds having hole transporting properties are substances including N,N-bis(4-biphenyl)amino, a light emitting device with a long lifetime can be manufactured, so they are preferred.

[0137] As the above-mentioned organic compound having hole transporting properties, specifically, 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-aminotriphenylbenzene (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4''-(7-phenyl)naphthalen-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binaphthalen-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-diphenyl-4''-(5;2'-binaphthalen-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenyl)-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(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(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-bis(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-Dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF), N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[9H-fluorene]-3-amine, N,N-bis(9,9-dimethyl-9H-[fluorene]-2-yl)-9,9'-spirobi[9H-fluorene]-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[9H-fluorene]-1-amine, N-(9,9-diphenyl-9H-fluoren-2-yl)-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: PCAFLP(2)), N-(9,9-diphenyl-9H-fluoren-2-yl)-N,9-diphenyl-9H-carbazol-2-amine (abbreviation: PCAFLP(2)-02), etc.

[0138] In addition, as organic compounds having hole-transporting properties, as other aromatic amine compounds, N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), etc. can also be used.

[0139] Note that in the hole injection layer 111, the organic compound having hole-transporting properties for the composite material is more preferably a material having a lower HOMO energy level with a HOMO energy level of -5.7 eV or higher and -5.4 eV or lower. When the organic compound having hole-transporting properties for the composite material has a lower HOMO energy level, holes are easily injected into the hole transport layer 112, and a light-emitting device with a long lifetime can be easily obtained. In addition, when the organic compound having hole-transporting properties for the composite material is a material having a lower HOMO energy level, the induction of holes is appropriately suppressed, so a light-emitting device with an even longer lifetime can be realized.

[0140] By forming the hole injection layer 111, the hole injection property can be improved, and thus a light-emitting device with a low driving voltage can be obtained.

[0141] In addition, the organic compound having acceptor properties in the material having acceptor properties is easily vapor-deposited and easily deposited, so it is an easy-to-use material.

[0142] The hole transport layer 112 is formed by including an organic compound having hole-transporting properties. The organic compound having hole-transporting properties preferably has 1×10-6 cm 2 A hole mobility of more than / Vs.

[0143] Examples of the organic compound having hole transporting properties described above include: 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviation: TPD), N,N'-bis(9,9'-spirobi[9H-fluorene]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-bis(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), and other compounds having an aromatic amine skeleton;1,3-Bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-bis(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 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(biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviation: BismBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H-3,3'-bicarbazole (abbreviation: mBPCCBP), 9-(2-naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: βNCCP), 9-(3-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCmBP), 9-(4-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCBP), 9,9'-di-2-naphthyl-3,3'-9H,9'H-bicarbazole (abbreviation: BisβNCz), 9-(2-naphthyl)-9'-[1,1':4',1''-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-5'-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':4',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-phenyl-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviation: PCCzTp), 9,9'-bis(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(4-biphenyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(triphenylene-2-yl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole and other compounds with a carbazole backbone;Compounds with a thiophene skeleton such as 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-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 compounds with a furan skeleton such as 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzofuran) (abbreviation: DBF3P-II), 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II). Among them, compounds with an aromatic amine skeleton or a carbazole skeleton have good reliability and high hole transportability and contribute to reducing the driving voltage, so they are preferred. Note that substances listed as hole-transporting organic compounds that can be appropriately used as materials for the hole injection layer 111 can also be used as materials for the hole transport layer 112.;

[0144] The light-emitting layer 113 preferably contains a light-emitting substance and a host material. Note that the light-emitting layer 113 may also contain other materials. In addition, it may also be a laminate of two layers with different compositions.

[0145] The light-emitting substance can be a fluorescent light-emitting substance, a phosphorescent light-emitting substance, a substance presenting thermally activated delayed fluorescence (TADF), or other light-emitting substances.

[0146] In the light-emitting layer 113, as materials that can be applied to fluorescent light-emitting substances, for example, the following substances can be cited. Note that, in addition, other fluorescent light-emitting substances can also be used.

[0147] Examples include 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'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenyldistyrene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)-4'-(10-phenyl-9-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), perylene, 2,5,8,11-tetra-tert-butyldiphenylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), N,N''-(2-tert-butylanthracene-9,10-diyl-di-4,1-phenylene)bis(N,N',N'-triphenyl-1,4-benzenediamine) (abbreviation: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: 2PCAPPA), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1,4-benzenediamine (abbreviation: 2DPAPPA), N,N,N',N',N'',N'',N''',N''' - octaphenyldibenzo[g,p] (chrysene)-2,7,10,15-tetraamine (abbreviation: DBC1), Coumarin 30, N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis(biphenyl-2-yl)-N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracen-9-amine (abbreviation: DPhAPhA), Coumarin 545T, N,N'-diphenylquinacridone (abbreviation: DPQd), Rubrene, 5,12-bis(biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]vinyl}-6-methyl-4H-pyran-4-ylidene)propanedinitrile (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)vinyl]-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)vinyl]-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)vinyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2,6-bis{2-[4-(dimethylamino)phenyl]vinyl}-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)vinyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJTM), N,N'-diphenyl-N,N'-(1,6-pyrene-diyl)bis[(6-phenylbenzo[b]naphtho[1,2-d]furan)-8-amine (abbreviation: 1,6BnfAPrn-03), 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), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02), etc. In particular, fused aromatic diamine compounds represented by pyrene diamine compounds such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03 have high hole capture properties, high luminous efficiency, and high reliability, so they are preferred.,

[0148] In the light-emitting layer 113, when a phosphorescent light-emitting material is used as the light-emitting substance, examples of materials that can be used include the following substances.

[0149] Examples include: tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: [Ir(mpptz-dmp)3]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazole)iridium(III) (abbreviation: [Ir(Mptz)3]), tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazole]iridium(III) (abbreviation: [Ir(iPrptz-3b)3]) and other organometallic iridium complexes having a 4H-triazole skeleton; tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazole]iridium(III) (abbreviation: [Ir(Mptz1-mp)3]), tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazole)iridium(III) (abbreviation: [Ir(Prptz1-Me)3]) and other organometallic iridium complexes having a 1H-triazole skeleton; fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpim)3]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me)3]) and other organometallic iridium complexes having an imidazole skeleton; 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’ iridium(III) acetylacetonate (abbreviation: FIracac), etc., which are organometallic iridium complexes with phenylpyridine derivatives having electron-withdrawing groups as ligands. The above substances are compounds that emit blue phosphorescence and are compounds having a luminescence peak in the wavelength region of 450 nm to 520 nm.

[0150] In addition, examples include: tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)3]), tris(4-tert-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)3]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)2(acac)]), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)2(acac)]), (acetylacetonato)bis[6-(2-norbornanyl)-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-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2(acac)]), etc., which are organometallic iridium complexes having a pyrimidine skeleton; (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)]), etc., which are organometallic iridium complexes having a pyrazine skeleton; 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-phenylquinoline-N,C 2’ )iridium(III) acetylacetonate (abbreviation: [Ir(pq)2(acac)]), [2-d3-methyl-8-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) (abbreviation: Ir(5mppy-d3)2(mbfpypy-d3)), {2-(methyl-d3)-8-[4-(1-methylethyl-1-d)-2-pyridinyl-κN]benzofuro[2,3-b]pyridine-7-yl-κC}bis{5-(methyl-d3)-2-[5-(methyl-d3)-2-pyridinyl-κN]phenyl-κC}iridium(III) (abbreviation: Ir(5mtpy-d6)2(mbfpypy-iPr-d4)), [2-d3-methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy)2(mbfpypy-d3)), [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy)2(mdppy)) and other organometallic iridium complexes having a pyridine skeleton; and rare earth metal complexes such as tris(acetylacetonato)(monophenanthroline) terbium(III) (abbreviation: [Tb(acac)3(Phen)]). The above substances are mainly compounds that exhibit green phosphorescence and have a luminescence peak in the wavelength region of 500 nm to 600 nm. In addition, organometallic iridium complexes having a pyrimidine skeleton are particularly preferred because they have particularly excellent reliability and luminescence efficiency.

[0151] In addition, examples include: bis[4,6-bis(3-methylphenyl)pyrimidinato](diisobutyrylmethanato)iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinato](dineopentanoylmethanato)iridium(III) (abbreviation: [Ir(5mdppm)2(dpm)]), bis[4,6-bis(naphthalen-1-yl)pyrimidinato](dineopentanoylmethanato)iridium(III) (abbreviation: [Ir(d1npm)2(dpm)]) and other organometallic iridium complexes with a pyrimidine skeleton; bis(2,3,5-triphenylpyrazinato)(acetylacetonato)iridium(III) (abbreviation: [Ir(tppr)2(acac)]), bis(2,3,5-triphenylpyrazinato)(dineopentanoylmethanato)iridium(III) (abbreviation: [Ir(tppr)2(dpm)]), bis(acetylacetonato)[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq)2(acac)]) and other organometallic iridium complexes with a pyrazine skeleton; tris(1-phenylisoquinoline-N,C 2’ )iridium(III) (abbreviation: [Ir(piq)3]), bis(1-phenylisoquinoline-N,C 2’ )iridium(III) acetylacetonate (abbreviation: [Ir(piq)2(acac)]) and other organometallic iridium complexes with a pyridine skeleton; platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(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)]), tris[1-(2-thienoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: [Eu(TTA)3(Phen)]). The above substances are compounds that exhibit red phosphorescence and have a luminescence peak in the wavelength region of 600 nm to 700 nm. In addition, organometallic iridium complexes with a pyrazine skeleton can obtain red luminescence with good chromaticity.

[0152] In addition, in addition to the above phosphorescent compounds, known phosphorescent compounds can also be selected and used.

[0153] As TADF materials, fullerenes and their derivatives, acridine and its derivatives, eosin derivatives, etc. can be used. In addition, metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), palladium (Pd), etc. can also be cited. As the metal-containing porphyrin, for example, protoporphyrin-tin fluoride complex (SnF2(Proto IX)), mesoporphyrin-tin fluoride complex (SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (SnF2(Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (SnF2(CoproIII-4Me)), octaethylporphyrin-tin fluoride complex (SnF2(OEP)), etioporphyrin-tin fluoride complex (SnF2(Etio I)), octaethylporphyrin-platinum chloride complex (PtCl2OEP), etc. represented by the following structural formulas can also be cited.

[0154] [Chemical formula 10]

[0155] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCzTzn), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 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-dihydroacridin)phenyl]sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthracene]-10'-one (abbreviation: ACRSA), etc., which have one or both of a π-rich heteroaromatic ring and a π-deficient heteroaromatic ring, can be used. The heteroaromatic compound has a π-rich heteroaromatic ring and a π-deficient heteroaromatic ring, and has high electron transportability and hole transportability, so it is preferred. Among them, in the skeleton having a π-deficient heteroaromatic ring, the pyridine skeleton, the diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton) and the triazine skeleton are stable and have high reliability, so they are preferred. In particular, the benzofuranopyrimidine skeleton, the benzothiophenopyrimidine skeleton, the benzofuranopyrazine skeleton, and the benzothiophenopyrazine skeleton have high acceptability and high reliability, so they are preferred. In addition, in the skeleton having a π-rich heteroaromatic ring, the acridine skeleton, the phenoxazine skeleton, the phenothiazine skeleton, the furan skeleton, the thiophene skeleton, and the pyrrole skeleton are stable and have high reliability, so it is preferred to have at least one of the above skeletons. In addition, as the furan skeleton, a dibenzofuran skeleton is preferably used, and as the thiophene skeleton, a dibenzothiophene skeleton is preferably used. As the pyrrole skeleton, an indole skeleton, a carbazole skeleton, an indolocarbazole skeleton, a bicarbazole skeleton, and a 3-(9-phenyl-9H-carbazol-3-yl)-9H-carbazole skeleton are particularly preferably used. In a substance in which a π-rich heteroaromatic ring and a π-deficient heteroaromatic ring are directly bonded, the electron-donating property of the π-rich heteroaromatic ring and the electron-accepting property of the π-deficient heteroaromatic ring are both high, and the energy difference between the S1 energy level and the T1 energy level becomes small, so thermally activated delayed fluorescence can be obtained efficiently, so it is particularly preferred. Note that an aromatic ring bonded with an electron-withdrawing group such as a cyano group can also be used instead of the π-deficient heteroaromatic ring. In addition, as the π-rich skeleton, an aromatic amine skeleton, a phenazine skeleton, etc. can be used.In addition, as the π-deficient electron skeleton, an oxygen xanthene skeleton, a thioxanthene dioxide skeleton, an oxadiazole skeleton, a triazole skeleton, an imidazole skeleton, an anthraquinone skeleton, a boron-containing skeleton such as phenylborane or boranthrene, an aromatic ring or heteroaromatic ring having a nitrile group or a cyano group such as benzonitrile or cyanobenzene, a carbonyl skeleton such as benzophenone, a phosphine oxide skeleton, a sulfone skeleton, etc. can be used. Thus, at least one of the π-deficient electron skeleton and the π-rich electron type skeleton can be used in place of the π-deficient electron type heteroaromatic ring and the π-rich electron type heteroaromatic ring.

[0156] [Chemical formula 11]

[0157] In addition, as the TADF material, a TADF material in a thermal equilibrium state between the singlet excited state and the triplet excited state can also be used. Since the emission lifetime (excitation lifetime) of this TADF material is short, a reduction in efficiency in the high-brightness region of the light-emitting device can be suppressed. Specifically, materials having the following molecular structures can be cited.

[0158] [Chemical formula 12]

[0159] The TADF material refers to a material in which the energy difference between the S1 energy level and the T1 energy level is small and which has a function of converting triplet excitation energy into singlet excitation energy through reverse intersystem crossing. Therefore, triplet excitation energy can be up-converted into singlet excitation energy (reverse intersystem crossing) by a small amount of thermal energy and singlet excited states can be efficiently generated. In addition, triplet excitation energy can be converted into light emission.

[0160] An exciplex formed by two substances in an excited state has the function of a TADF material that can convert triplet excitation energy into singlet excitation energy because the energy difference between the S1 energy level and the T1 energy level is extremely small.

[0161] Note that as an index of the T1 energy level, a phosphorescence spectrum observed at a low temperature (for example, 77 K to 10 K) can be used. Regarding the TADF material, preferably, when the wavelength energy of the extrapolation line obtained by drawing a tangent at the tail on the short-wavelength side of the fluorescence spectrum is the S1 energy level and the wavelength energy of the extrapolation line obtained by drawing a tangent at the tail on the short-wavelength side of the phosphorescence spectrum is the T1 energy level, the energy difference between the S1 energy level and the T1 energy level is 0.3 eV or less, more preferably 0.2 eV or less.

[0162] In addition, when a TADF material is used as the light-emitting substance, the S1 energy level of the host material is preferably higher than the S1 energy level of the TADF material. In addition, the T1 energy level of the host material is preferably higher than the T1 energy level of the TADF material.

[0163] As the host material of the light-emitting layer 113, various charge carrier transport materials such as materials having electron transport properties and / or materials having hole transport properties, and the above-mentioned TADF materials can be used.

[0164] As a material having hole transporting properties, an organic compound having an amine skeleton or a π-electron-rich heteroaromatic ring skeleton is preferably used. For example, the following can be cited: 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviation: TPD), N,N'-bis(9,9'-spirobi[9H-fluorene]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-bis(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluorene-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF) and other compounds having an aromatic amine skeleton; 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-bis(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP) and other compounds having a carbazole skeleton; 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenylfluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4-[4-(9-phenylfluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV) and other compounds having a thiophene skeleton; and 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzofuran) (abbreviation: DBF3P-II), 4-{3-[3-(9-phenylfluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II) and other compounds having a furan skeleton. Among them, the compound having an aromatic amine skeleton or the compound having a carbazole skeleton has high reliability and excellent hole transporting properties and helps to reduce the driving voltage, so it is preferred.In addition, an organic compound cited as a material having hole-transporting properties in the hole-transporting layer can also be used.

[0165] As materials having electron-transporting properties, for example, the following are preferably used: metal complexes such as bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2), bis(2-methyl-8-hydroxyquinolinato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), bis(8-hydroxyquinolinato)zinc(II) (abbreviation: Znq), bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO), bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ), etc., and organic compounds including π-deficient heteroaromatic rings. As organic compounds including π-deficient heteroaromatic rings, for example, the following can be cited: organic compounds having an oxazole skeleton such as 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 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), 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), etc.; organic compounds containing heteroaromatic rings having a pyridine skeleton such as 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tris[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), bathophenanthroline (abbreviation: Bphen), bathocuproine (abbreviation: BCP), 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), 2,2'-biphenyl-4,4'-diylbis(1,10-phenanthroline) (abbreviation: Phen2BP), etc.; 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3-(3'-dibenzothiophen-4-yl)biphenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4'-(9-phenyl-9H-carbazol-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), 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), 6-[3-(Dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 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), 4,6-Bis[3-(phenanthren-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: 4,6mCzP2Pm), 9,9’-[Pyrimidine-4,6-diylbis(biphenyl-3,3’-diyl)]bis(9H-carbazole) (abbreviation: 4,6mCzBP2Pm), 8-(Biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 3,8-Bis[3-(dibenzothiophen-4-yl)phenyl]benzofuro[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-Bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3’-(Dibenzothiophen-4-yl)(biphenyl-3-yl)]naphtho[1’,2’:4,5]furo[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2’-Binaphthalen)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm), 2,2’-(Pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6(P-Bqn)2Py), 2,2’-(Pyridine-2,6-diyl)bis{4-[4-(naphthalen-2-yl)phenyl]-6-phenylpyrimidine} (abbreviation: 2,6(NP-PPm)2Py), 6-(Biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 2,6-Bis(4-naphthalen-1-ylphenyl)-4-[4-(pyridin-3-yl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 7-[4-(9-phenyl-9H-carbazol-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: PC-cgDBCzQz), etc., which are organic compounds containing heteroaromatic rings with a diazine skeleton; 2-(biphenyl-4-yl)-4-phenyl-6-(9,9'-spirobi[9H-fluorene]-2-yl)-1,3,5-triazine (abbreviation: BP-SFTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn-02), 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), 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 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-[3-(dibenzothiophen-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTzn), 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), 2-[3-(2,6-dimethyl-3-pyridyl)-5-(9-phenanthryl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTzn), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazin-2-yl]-11,12-dihydro-12-phenylindolo[2,3-a]carbazole (abbreviation: BP-Icz(II)Tzn), 2-[3'-(triphenylene-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mTpBPTzn), 3-[9-(4,6-diphenyl-1,3,5-(Triazin-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-(biphenyl-3-yl)-4-phenyl-6-{8-[(1,1’:4’,1”-terphenyl)-4-yl]-1-dibenzofuranyl}-1,3,5-triazine (abbreviation: mBP-TPDBfTzn), etc., which are organic compounds containing heteroaromatic rings having a triazine skeleton. Among them, organic compounds containing heteroaromatic rings having a diazine skeleton, organic compounds containing heteroaromatic rings having a pyridine skeleton, and organic compounds containing heteroaromatic rings having a triazine skeleton have good reliability, so they are preferred. In particular, organic compounds containing heteroaromatic rings having a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing heteroaromatic rings having a triazine skeleton have high electron transport properties, which helps to reduce the driving voltage.,

[0166] As the TADF material that can be used as the host material, the same materials as those exemplified above as the TADF material can be used. When the TADF material is used as the host material, the triplet excitation energy generated by the TADF material is converted into singlet excitation energy through reverse intersystem crossing and further transferred to the luminescent material, thereby improving the luminous efficiency of the light-emitting device. At this time, the TADF material is used as the energy donor and the luminescent material is used as the energy acceptor.

[0167] This is very effective when the above luminescent material is a fluorescent luminescent material. In addition, at this time, in order to obtain high luminous efficiency, the S1 energy level of the TADF material is preferably higher than the S1 energy level of the fluorescent luminescent material. In addition, the T1 energy level of the TADF material is preferably higher than the S1 energy level of the fluorescent luminescent material. Therefore, the T1 energy level of the TADF material is preferably higher than the T1 energy level of the fluorescent luminescent material.

[0168] In addition, it is preferable to use a TADF material that emits light overlapping the wavelength of the absorption band on the lowest energy side of the fluorescent luminescent material. Thus, the excitation energy is smoothly transferred from the TADF material to the fluorescent luminescent material, and high-efficiency light emission can be obtained, so it is preferred.

[0169] In order to efficiently generate singlet excited energy from triplet excited energy through reverse intersystem crossing, it is preferable to generate carrier recombination in the TADF material. Additionally, it is preferable that the triplet excited energy generated in the TADF material does not transfer to the triplet excited energy of the fluorescent emitter. For this purpose, the fluorescent emitter preferably has a protecting group around the emitter (the skeleton that causes luminescence) possessed by the fluorescent emitter. As this protecting group, a substituent without a π bond is preferable, and a saturated hydrocarbon is preferable. Specifically, an alkyl group having 3 or more and 10 or less carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 or more and 12 or less carbon atoms, or a trialkylsilyl group having 3 or more and 10 or less carbon atoms can be cited. More preferably, it has a plurality of protecting groups. Since the substituent without a π bond has almost no function of transporting carriers, it has almost no influence on carrier transport or carrier recombination, and can keep the emitter of the TADF material and the fluorescent emitter away from each other. Here, the emitter refers to the atomic group (skeleton) that causes luminescence in the fluorescent emitter. The emitter preferably has a skeleton with a π bond, preferably includes an aromatic ring, and preferably includes a fused aromatic ring or a fused heteroaromatic ring. As the above-mentioned emitter, for example, a phenanthrene skeleton, a stilbene skeleton, an acridone skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, a naphthobisbenzofuran skeleton, etc. In particular, fluorescent emitters having a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, a naphthobisbenzofuran skeleton have a high fluorescence quantum yield, so they are preferable.

[0170] In the case of using a fluorescent light-emitting substance as the light-emitting substance, as the host material, a material having an anthracene skeleton is preferably used. By using a substance having an anthracene skeleton as the host material of the fluorescent light-emitting substance, a light-emitting layer with high luminous efficiency and durability can be achieved. Among the substances having an anthracene skeleton used as the host material, a substance having a diphenylanthracene skeleton, especially a 9,10-diphenylanthracene skeleton, is chemically stable and thus preferred. In addition, when the host material has a carbazole skeleton, the hole injection / transport property is improved, so it is preferred. However, when there is a benzocarbazole skeleton in which a benzene ring is also fused to the carbazole skeleton, its HOMO is about 0.1 eV higher than that of the host material having a carbazole skeleton and it is easier to inject holes, so it is more preferred. In particular, when the host material has a dibenzocarbazole skeleton, its HOMO is about 0.1 eV higher than that of the host material having a carbazole skeleton, and not only is it easy to inject holes, but also the hole transport property and heat resistance are improved, so it is preferred. Therefore, a substance further preferably used as the host material is a substance having a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzocarbazole skeleton or a dibenzocarbazole skeleton). Note that from the above viewpoint of hole injection / transport property, a benzofluorene skeleton or a dibenzofluorene skeleton can also be used instead of the carbazole skeleton. Examples of such substances include 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA), 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]benzo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10-[4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4'-yl]anthracene (abbreviation: FLPPA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviation: α,βADN), 2-(10-phenylanthracen-9-yl)dibenzofuran, 2-(10-phenyl-9-anthryl)benzo[b]naphtho[2,3-d]furan (abbreviation: Bnf(II)PhA), 9-(2-naphthyl)-10-[3-(2-naphthyl)phenyl]anthracene (abbreviation: βN-mβNPAnth), 1-{4-[10-(biphenyl-4-yl)-9-anthryl]phenyl}-2-ethyl-1H-benzimidazole (abbreviation: EtBImPBPhA), etc. In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA exhibit very good characteristics and are thus preferred.

[0171] In addition, the host material can also be a material that mixes multiple substances. When using a mixed host material, it is preferable to mix a material with electron-transporting properties and a material with hole-transporting properties. By mixing a material with electron-transporting properties and a material with hole-transporting properties, it becomes easier to adjust the transport properties of the light-emitting layer 113, and it is also possible to more simply control the recombination region. The weight ratio of the content of the material with hole-transporting properties to the content of the material with electron-transporting properties can be from 1:19 to 19:1.

[0172] Note that, as part of the above-mentioned mixed materials, a phosphorescent light-emitting substance can be used. The phosphorescent light-emitting substance can be used as an energy donor that supplies excitation energy to the fluorescent light-emitting substance when the fluorescent light-emitting substance is used as the light-emitting substance.

[0173] In addition, these mixed materials can also be used to form an exciplex. By selecting a combination that forms an exciplex that emits light overlapping the wavelength of the absorption band on the lowest energy side of the light-emitting substance, energy transfer can be made smooth, and thus light emission can be obtained efficiently, so it is preferable. In addition, by adopting this structure, the driving voltage can be reduced, so it is preferable.

[0174] Note that at least one of the materials forming the exciplex can also be a phosphorescent light-emitting substance. Thereby, triplet excitation energy can be efficiently converted into singlet excitation energy through reverse intersystem crossing.

[0175] As a combination of materials that efficiently form an exciplex, the HOMO energy level of the material with hole-transporting properties is preferably higher than the HOMO energy level of the material with electron-transporting properties. In addition, the LUMO energy level of the material with hole-transporting properties is preferably higher than the LUMO energy level of the material with electron-transporting properties. Note that the LUMO energy level and HOMO energy level of the material can be obtained from the electrochemical properties (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV).

[0176] Note that the formation of an exciplex can be confirmed, for example, by comparing the emission spectra of a material with hole-transporting properties, the emission spectra of a material with electron-transporting properties, and the emission spectra of a mixed film formed by mixing these materials. When a phenomenon is observed in which the emission spectrum of the mixed film shifts to the longer wavelength side (or has a new peak on the longer wavelength side) compared to the emission spectra of the respective materials, it indicates the formation of an exciplex. Alternatively, the transient photoluminescence (PL) of a material with hole-transporting properties, the transient PL of a material with electron-transporting properties, and the transient PL of a mixed film formed by mixing these materials are compared. When a difference in transient response is observed, such as an increase in the ratio of the long-lived component or the delayed component of the transient PL lifetime of the mixed film compared to the transient PL lifetimes of the respective materials, it indicates the formation of an exciplex. In addition, the above transient PL can be referred to as transient electroluminescence (EL). In other words, by comparing the transient EL of a material with hole-transporting properties, the transient EL of a material with electron-transporting properties, and the transient EL of a mixed film of these materials, and observing the difference in transient response, the formation of an exciplex can be confirmed.

[0177] The electron transport layer 114 is a layer containing a material with electron-transporting properties. As the material with electron-transporting properties, a material having an electron mobility of 1×10 -7 cm 2 / Vs or more, preferably 1×10 -6 cm 2 / Vs or more when the square root of the electric field strength [V / cm] is 600 is preferably used. In addition, as long as the material has higher electron-transporting properties than hole-transporting properties, materials other than the above can also be used. As the above organic compound, an organic compound including a π-deficient heteroaromatic ring is preferably used. As the organic compound including a π-deficient heteroaromatic ring, for example, an organic compound including a heteroaromatic ring having a triazole skeleton, an organic compound including a heteroaromatic ring having a pyridine skeleton, an organic compound including a heteroaromatic ring having a diazine skeleton, and an organic compound including a heteroaromatic ring having a triazine skeleton, any one or more of them are preferably used.

[0178] As the organic compound with electron-transporting properties that can be used for the electron transport layer 114, the material with electron-transporting properties that can be used as the host material for the light-emitting layer 113 can be used in the same manner. Among them, an organic compound including a heteroaromatic ring having a diazine skeleton, an organic compound including a heteroaromatic ring having a pyridine skeleton, and an organic compound including a heteroaromatic ring having a triazine skeleton have good reliability, so they are preferred. In particular, an organic compound including a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and an organic compound including a heteroaromatic ring having a triazine skeleton have high electron-transporting properties and contribute to reducing the driving voltage.

[0179] In addition, the electron transport layer 114 preferably has an electron mobility of 1×10 -7 cm 2 / Vs or more and 5×10 -5 cm 2 / Vs or less when the square root of the electric field strength [V / cm] is 600. By reducing the transportability of electrons in the electron transport layer 114, the amount of electrons injected into the light-emitting layer can be controlled, thereby preventing the light-emitting layer from becoming a state with an excessive amount of electrons. When a composite material is used to form the hole injection layer and the HOMO energy level of the hole-transporting material in the composite material is a relatively low HOMO energy level of -5.7 eV or more and -5.4 eV or less, by adopting the above structure, a long lifetime can be obtained, so it is particularly preferred. Note that at this time, the HOMO energy level of the electron-transporting material is preferably -6.0 eV or more.

[0180] As the electron injection layer 115, in addition to the above-mentioned organic compound having a basic skeleton, a layer including an alkali metal, an alkaline earth metal, a rare earth metal, or a compound or complex thereof such as lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), 8-hydroxyquinoline-lithium (abbreviation: Liq), ytterbium (Yb), etc. can also be used. The electron injection layer 115 can use a layer in which an alkali metal, an alkaline earth metal, or a compound thereof is contained in a layer composed of an electron-transporting substance or an electride. As an electride, for example, a substance that adds electrons to a mixed oxide of calcium and aluminum at a high concentration can be cited.

[0181] Note that as the electron injection layer 115, a layer in which an electron-transporting substance (preferably an organic compound having a bipyridine skeleton) contains a fluoride of the above-mentioned alkali metal or alkaline earth metal at a concentration above the microcrystalline state concentration (50 wt% or more) can also be used. Since this layer is a layer with a low refractive index, a light-emitting device with better external quantum efficiency can be provided.

[0182] In addition, as a method for forming the organic compound layer 103, various methods can be used regardless of the dry method or the wet method. For example, a vacuum evaporation method, a gravure printing method, a lithographic printing method, a screen printing method, an inkjet method, a spin coating method, etc. can also be used.

[0183] In addition, the above-mentioned respective electrodes or layers can also be formed by using different deposition methods.

[0184] Here, the mechanism of a light-emitting device using an organic compound having a strong basicity for the electron injection layer will be described.

[0185] When an organic compound with strong basicity is used instead of an alkali metal or alkaline earth metal typified by an Li compound or their compounds, the organic compound with strong basicity is not used as a donor. Thus, when the difference between the Fermi level (E F ) of the electrode (cathode) and the LUMO level of the material with electron-transporting property is large, it is difficult to inject electrons ( Figure 2A ). Therefore, the driving voltage of a light-emitting device using an organic compound with basicity instead of an Li compound as an electron injection layer increases significantly.

[0186] Here, the inventors have found that by making the electron transport layer include a mixed layer of an organic compound with electron-transporting property and an organic compound with hole-transporting property, a light-emitting device using an organic compound with strong basicity instead of an Li compound as an electron injection layer can suppress a large increase in the driving voltage.

[0187] This can be explained by a new knowledge that holes flow through electrons but are blocked (do not flow) in the EL layer containing an organic compound with strong basicity, the generation of an electric dipole due to the accumulation of charges, and the driving mechanism such as the drift of the vacuum level caused thereby.

[0188] First, since the hole-transporting property of the electron transport layer that blocks holes or the electron transport layer is low, holes injected from the anode accumulate near the interface on the electron injection layer side in the light-emitting layer or the electron transport layer. Note that at this time, the electron injection layer is preferably a layer that blocks holes or a layer with a significantly low hole mobility. When the electron injection layer contains an organic compound with strong basicity, holes accumulate near the interface on the first electron transport layer side of the electron injection layer ( Figure 2B ).

[0189] In addition, in a light-emitting device using an electron injection layer containing an organic compound with strong basicity, even when a voltage is applied as described above, electrons are not easily injected due to the difference between the Fermi level of the electrode and the LUMO level of the material with electron-transporting property, and electrons accumulate near the interface on the electron injection layer side in the cathode (note that when the electron injection layer does not contain a material with electron-transporting property, that is, a single film of an organic compound with strong basicity, electrons accumulate on the single film side of the organic compound with strong basicity).

[0190] Thus, in a light-emitting device according to one embodiment of the present invention, holes accumulate near the interface on the electron transport layer side of the electron injection layer, and electrons accumulate on the electron injection layer side of the cathode. The accumulated charges form a double layer, generate an electric dipole, and cause a vacuum level drift, so that the Fermi level of the cathode material approaches the LUMO level of the material with electron-transporting property in the electron injection layer, and electrons are injected into the EL layer at a low voltage.

[0191] Next, refer to Figure 3AA method for explaining a light-emitting device having a structure in which a plurality of light-emitting units are stacked (also referred to as a stacked device or a series device). The light-emitting device is a light-emitting device having a plurality of light-emitting units between an anode and a cathode. One light-emitting unit has a structure substantially the same as that of the organic compound layer 103 shown in Figure 1 That is to say, Figure 3A the light-emitting device shown in is a light-emitting device having a plurality of light-emitting units, while Figure 1 the light-emitting device shown in is a light-emitting device having one light-emitting unit.

[0192] In Figure 3A , a first light-emitting unit 511 and a second light-emitting unit 512 are stacked between a first electrode 501 and a second electrode 502, and an intermediate layer 513 is provided between the first light-emitting unit 511 and the second light-emitting unit 512. The first electrode 501 and the second electrode 502 respectively correspond to the first electrode 101 and the second electrode 102 in Figure 1 , and the same as that described in Figure 1 can be applied. In addition, the first light-emitting unit 511 and the second light-emitting unit 512 may have the same structure or different structures.

[0193] The intermediate layer 513 has a function of injecting electrons into one light-emitting unit and injecting holes into the other light-emitting unit when a voltage is applied to the first electrode 501 and the second electrode 502. That is to say, in Figure 3A , when a voltage is applied in such a way that the potential of the anode is higher than the potential of the cathode, the intermediate layer 513 may be a layer that injects electrons into the first light-emitting unit 511 and injects holes into the second light-emitting unit 512.

[0194] The intermediate layer 513 includes a charge generation layer. In addition, the charge generation layer at least includes a P-type layer 117. The P-type layer 117 is preferably formed using the composite material that constitutes the hole injection layer 111 described above. In addition, the P-type layer 117 may also be formed by laminating a film containing an acceptor material and a film containing a hole-transporting material, which have been described above as the materials constituting the composite material. By applying a potential to the P-type layer 117, electrons and holes are respectively injected into the electron transport layer included in the first light-emitting unit 511 and the hole transport layer included in the second light-emitting unit 512, so that the light-emitting device operates.

[0195] In addition, the intermediate layer 513 preferably further includes one or both of an electron relay layer 118 and an N-type layer 119 in addition to the P-type layer 117. Figure 3B shows a structure in which the intermediate layer 513 includes a P-type layer 117, an electron relay layer 118, and an N-type layer 119. In addition, it is preferable to appropriately select the lamination order of the layers in the intermediate layer 513 according to the voltage applied between the first electrode 501 and the second electrode 502 and the like.

[0196] The electron relay layer 118 contains at least a substance with electron-transporting properties, can prevent the interaction between the N-type layer 119 and the P-type layer 117, and can transfer electrons smoothly. It is preferable to set the LUMO energy level of the substance with electron-transporting properties contained in the electron relay layer 118 between the LUMO energy level of the electron-accepting substance in the P-type layer 117 and the LUMO energy level of the substance contained in the layer in the electron-transporting layer of the first light-emitting unit 511 that contacts the intermediate layer 513. The LUMO energy level of the substance with electron-transporting properties in the electron relay layer 118 is -5.0 eV or more, preferably -5.0 eV or more and -3.0 eV or less. In addition, as the substance with electron-transporting properties in the electron relay layer 118, a phthalocyanine-based material or a metal complex having a metal-oxygen bond and an aromatic ligand is preferably used.

[0197] The N-type layer 119 can use substances with high electron-injecting properties such as alkali metals, alkaline earth metals, rare earth metals, and compounds of these substances (alkali metal compounds (including oxides such as lithium oxide, halides, carbonates such as lithium carbonate and cesium carbonate), alkaline earth metal compounds (including oxides, halides, carbonates), or compounds of rare earth metals (including oxides, halides, carbonates)).

[0198] In addition, when the N-type layer 119 contains a substance with electron-transporting properties and a donor substance, as the donor substance, in addition to alkali metals, alkaline earth metals, rare earth metals, and compounds of these substances (alkali metal compounds (including oxides such as lithium oxide, halides, carbonates such as lithium carbonate and cesium carbonate), alkaline earth metal compounds (including oxides, halides, carbonates), or compounds of rare earth metals (including oxides, halides, carbonates)), organic compounds such as tetrathianaphthacene (abbreviation: TTN), nickelocene, and decamethylnickelocene can also be used. In addition, as the substance with electron-transporting properties, the same materials as those described above for the electron-transporting layer 114 can be used.

[0199] In addition, a layer containing a strongly basic organic compound described above as the layer used as the electron-injecting layer 115 can be provided at the same position as the N-type layer 119 instead of the N-type layer 119. A tandem light-emitting device can also be manufactured with this structure.

[0200] In this case, even when a voltage is applied to a tandem light-emitting device in which a layer containing an organic compound having strong basicity is used instead of the N-type layer 119, the organic compound having strong basicity is not used as a donor and electrons are not generated in the layer containing the organic compound having strong basicity (hereinafter, this layer is referred to as DLL). On the other hand, holes injected from the anode accumulate between the DLL or the light-emitting layer in the first light-emitting unit 511 and the electron transport layer.

[0201] Due to the application of the voltage and the accumulation of holes, electrons are induced by the P-type layer 117, and the electrons induced by the P-type layer 117 accumulate at the interface on the DLL side in the P-type layer 117 because of the large difference in the LUMO levels between the acceptor-type material contained in the P-type layer 117 and the electron-transporting material contained in the DLL (note that when the DLL does not contain an electron-transporting material, i.e., a single film of an organic compound having strong basicity, the electrons generated in the P-type layer 117 accumulate on the side of the single film of the organic compound having strong basicity). The accumulated electrons and the holes accumulated between the DLL or the light-emitting layer in the first light-emitting unit 511 and the electron transport layer together form a double layer, thereby generating an electric dipole.

[0202] As a result, the vacuum level drifts, the LUMO levels of the acceptor-type material contained in the P-type layer 117 and the electron-transporting material of the DLL approach, and the electrons generated in the P-type layer 117 are injected into the DLL. Then, the electrons injected into the DLL are also injected into the first light-emitting unit 511, reach the light-emitting layer included in the first light-emitting unit 511 and recombine, thereby obtaining light emission in the first light-emitting unit 511. Thus, a light-emitting device using the DLL containing an organic compound having strong basicity instead of the N-type layer 119 can be used as a tandem light-emitting device.

[0203] Note that at this time, preferably, the layer containing the organic compound having strong basicity has the same structure as the electron injection layer 115. That is, a mixed layer containing at least two or more organic compounds is preferably used as the layer containing the organic compound having strong basicity, which contains a third organic compound having strong basicity and a fourth organic compound having a LUMO level lower than that of the third organic compound. That is, the LUMO level of the third organic compound having strong basicity is preferably higher than the LUMO level of the fourth organic compound. Thus, the formation of an unstable excited state can be suppressed and the reliability can be improved.

[0204] Note that the above-mentioned organic compound having strong basicity preferably does not have an electron-transporting skeleton. This is to suppress the recombination of electrons injected into the electron injection layer 115 and holes captured by the organic compound having strong basicity to efficiently inject into the first light-emitting unit 511.

[0205] Note that when the surface on the cathode side of the first light-emitting unit 511 is in contact with the intermediate layer 513, the intermediate layer 513 can also function as an electron injection layer for the first light-emitting unit 511. Therefore, an electron injection layer may not be provided in the first light-emitting unit 511 either. Additionally, when the surface on the anode side of the second light-emitting unit 512 is in contact with the intermediate layer 513, the charge generation layer of the intermediate layer 513 can also function as a hole injection layer for the second light-emitting unit 512. Therefore, a hole injection layer may not be provided in the second light-emitting unit 512 either.

[0206] Although a light-emitting device having two light-emitting units has been described in Figure 3A , the same applies to a light-emitting device in which three or more light-emitting units are stacked. As in the light-emitting device according to the present embodiment, by separating and arranging a plurality of light-emitting units using the intermediate layer 513 between a pair of electrodes, the device can achieve high-brightness light emission while maintaining a low current density, and can realize an element with a long lifespan. In addition, a light-emitting device capable of low-voltage driving and low power consumption can be realized.

[0207] Furthermore, by making the light-emitting colors of the respective light-emitting units different, light emission of a desired color can be obtained from the entire light-emitting device. For example, by obtaining red and green light-emitting colors from the first light-emitting unit and a blue light-emitting color from the second light-emitting unit in a light-emitting device having two light-emitting units, a light-emitting device that emits white light throughout can be obtained.

[0208] In addition, each layer and electrode such as the above-mentioned organic compound layer 103, the first light-emitting unit 511, the second light-emitting unit 512, and the charge generation layer can be formed by methods such as vapor deposition (including vacuum vapor deposition), droplet ejection (also called inkjet), coating, gravure printing, etc. Furthermore, it can also include low-molecular materials, medium-molecular materials (including oligomers, dendrimers), or high-molecular materials.

[0209] Figure 4A Adjacent two light-emitting devices (light-emitting device 130a, light-emitting device 130b) included in a light-emitting device showing one aspect of the present invention are shown.

[0210] The light-emitting device 130a includes an organic compound layer 103a between a first electrode 101a on an insulating layer 175 and a second electrode 102 opposite thereto. Although the organic compound layer 103a is shown as having a structure including a hole injection layer 111a, a hole transport layer 112a, a light-emitting layer 113a, an electron transport layer 114a, and an electron injection layer 115a, it can also be a layer having a different laminated structure.

[0211] The light-emitting device 130b includes an organic compound layer 103b between a first electrode 101b on an insulating layer 175 and a second electrode 102 opposite thereto. Although the organic compound layer 103b is shown as having a structure including a hole injection layer 111b, a hole transport layer 112b, a light-emitting layer 113b, an electron transport layer 114b, and an electron injection layer 115b, it may also be a layer having a different stacked structure.

[0212] Generally, an alkali metal such as lithium (Li) having a small work function or a compound of an alkali metal is used in the electron injection layer of a light-emitting device. By using the above-mentioned alkali metal or its compound, good electron injectability can be ensured. In addition, due to the interaction between the above-mentioned alkali metal or its compound and the electron-transporting material, charge injection ability can be ensured and electrons can be injected into the electron transport layer. Therefore, by using the above-mentioned alkali metal or its compound in the electron injection layer, low voltage operation of the device can be achieved.

[0213] However, the above-mentioned alkali metal or its compound is a material that is easily oxidized and unstable. Therefore, there is a problem that if it reacts with atmospheric components such as water or oxygen during the manufacturing process of the light-emitting device, a significant increase in the driving voltage of the light-emitting device or a significant decrease in the light-emitting efficiency may occur. Therefore, an organic EL device needs to be manufactured in an atmosphere of a vacuum or an inert gas such as nitrogen.

[0214] In addition, as one of the methods for forming the organic compound layer into a specified shape, a vacuum evaporation method using a metal mask (mask evaporation) is widely used. However, with the progress of high density and high fineness, due to various reasons represented by the problems of positional alignment accuracy and the configuration interval from the substrate, further high fineness of mask evaporation is approaching its limit. On the other hand, by using photolithography to process the shape of the organic compound film, a denser pattern can be formed. In this method, since it is also easy to achieve large area processing, research on the processing of the organic compound film using photolithography has been carried out.

[0215] For example, a light-emitting device according to one embodiment of the present invention can also be manufactured using a lithographic technique such as photolithography. When manufacturing using photolithography, at least the light-emitting layer and the organic compound layer closer to the first electrode side than the light-emitting layer are processed simultaneously, and thus have a shape in which their ends are substantially aligned in the vertical direction.

[0216] In addition, when manufacturing a light-emitting device using photolithography, when the electron injection layer is exposed to the atmosphere, a resist resin, water, or a chemical solution during the processing step, in the case of a device in which the electron injection layer contains an alkali metal or its compound, the electron injection layer may deteriorate due to this step, resulting in a significant decrease in characteristics. That is, since the layer of the alkali metal or its compound in the electron injection layer is exposed to the photolithography process, a significant increase in the driving voltage of the light-emitting device or a significant decrease in the light-emitting efficiency may occur.

[0217] Therefore, the structure of the electron injection layer 115a in the light-emitting device 130a and the structure of the electron injection layer 115b in the light-emitting device 130b are preferably the structure of the above-mentioned electron injection layer 115.

[0218] The second electrode 102 is preferably a continuous layer shared by the light-emitting device 130a and the light-emitting device 130b. In addition, the organic compound layer 103a and the organic compound layer 103b are processed by photolithography after the formation of the electron injection layer 115a and after the formation of the electron injection layer 115b, respectively, so they are independent of each other. In addition, the end portions (profiles) of the organic compound layer 103a are processed by photolithography, so they are substantially aligned in the direction perpendicular to the substrate. In addition, the end portions (profiles) of the organic compound layer 103b are processed by photolithography, so they are substantially aligned in the direction perpendicular to the substrate.

[0219] In addition, due to the processing by photolithography, there is a gap d between the organic compound layer 103a and the organic compound layer 103b. In addition, since the organic compound layer is processed by photolithography, the distance between the first electrode 101a and the first electrode 101b can be made smaller than that distance during mask evaporation, that is, it can be 2 μm or more and 5 μm or less. In addition, an insulating layer can be provided in the gap d, and the insulating layer is in contact with the second electrode 102.

[0220] Figure 4B Two adjacent series-connected light-emitting devices (light-emitting devices 130c, 130d) manufactured by photolithography are shown.

[0221] The light-emitting device 130c includes an organic compound layer 103c between the first electrode 501c on the insulating layer 175 and the second electrode 502 opposite thereto. The organic compound layer 103c has a structure in which a first light-emitting unit 511c and a second light-emitting unit 512c sandwich an intermediate layer 513c. Note that, although Figure 4B An example in which two light-emitting units are stacked is shown, but three or more light-emitting units can also be stacked. The first light-emitting unit 511c includes a hole injection layer 111c, a first hole transport layer 112c_1, a first light-emitting layer 113c_1, and a first electron transport layer 114c_1. The intermediate layer 513c includes a second layer 117c, an electron relay layer 118c, and a first layer 119c. Regardless of the presence or absence of the electron relay layer 118c. The second light-emitting unit 512c includes a second hole transport layer 112c_2, a second light-emitting layer 113c_2, a second electron transport layer 114c_2, and an electron injection layer 115c.

[0222] The light-emitting device 130d includes an organic compound layer 103d between the first electrode 501d on the insulating layer 175 and the second electrode 502 opposite thereto. The organic compound layer 103d has a structure in which a first light-emitting unit 511d and a second light-emitting unit 512d sandwich an intermediate layer 513d and are stacked. Note that, although Figure 4B an example of stacking two light-emitting units is shown, three or more light-emitting units may also be stacked. The first light-emitting unit 511d includes a hole injection layer 111d, a first hole transport layer 112d_1, a first light-emitting layer 113d_1, and a first electron transport layer 114d_1. The intermediate layer 513d includes a second layer 117d, an electron relay layer 118d, and a first layer 119d. Regardless of the presence or absence of the electron relay layer 118d. The second light-emitting unit 512d includes a second hole transport layer 112d_2, a second light-emitting layer 113d_2, a second electron transport layer 114d_2, and an electron injection layer 115d.

[0223] The structure of the electron injection layer 115c in the light-emitting device 130c and the structure of the electron injection layer 115d in the light-emitting device 130d are preferably the structure of the above-mentioned electron injection layer 115.

[0224] The second electrode 502 is preferably a continuous layer shared by the light-emitting device 130c and the light-emitting device 130d. In addition, since the organic compound layer 103c and the organic compound layer 103d are respectively processed by photolithography after forming the electron injection layer 115c and after forming the electron injection layer 115d, they are independent of each other. In addition, since the end (profile) of the organic compound layer 103c is processed by photolithography, it is substantially consistent in the direction perpendicular to the substrate. In addition, since the end (profile) of the organic compound layer 103d is processed by photolithography, it is substantially consistent in the direction perpendicular to the substrate.

[0225] In addition, due to processing by photolithography, there is a gap d between the organic compound layer 103c and the organic compound layer 103d. In addition, since the organic compound layer is processed by photolithography, the distance between the first electrode 501c and the first electrode 501d can be made smaller than this distance during mask evaporation, that is, it can be 2 μm or more and 5 μm or less.

[0226] This embodiment can be appropriately combined with other embodiments or examples. In addition, in this specification, when multiple structural examples are shown in one embodiment, these structural examples can be appropriately combined.

[0227] (Embodiment 2) As Figure 5A and Figure 5BAs shown, a light-emitting device is formed by forming a plurality of the light-emitting devices 130 described in the above embodiments on an insulating layer 175. In the present embodiment, a light-emitting device according to one aspect of the present invention will be described in detail.

[0228] The light-emitting device 1000 includes a pixel portion 177 in which a plurality of pixels 178 are arranged in a matrix. The pixel 178 includes a sub-pixel 110R, a sub-pixel 110G, and a sub-pixel 110B.

[0229] In this specification and the like, sometimes, for example, the term "sub-pixel 110" is used to describe the common content among the sub-pixel 110R, the sub-pixel 110G, and the sub-pixel 110B. In addition, for the components distinguished by letters, sometimes the symbols omitting the letters are used to describe the common content among the components.

[0230] The sub-pixel 110R emits red light, the sub-pixel 110G emits green light, and the sub-pixel 110B emits blue light. Thus, an image can be displayed on the pixel portion 177. Note that in the present embodiment, sub-pixels of three colors, red (R), green (G), and blue (B), are taken as examples for description, but the present invention is not limited to this structure. That is, sub-pixels of other colors may be combined. For example, the number of sub-pixels is not limited to three and may be four or more. As four sub-pixels, for example, sub-pixels of four colors, R, G, B, and white (W); sub-pixels of four colors, R, G, B, and yellow (Y); and four sub-pixels of R, G, B, and infrared light (IR) can be cited; etc.

[0231] In this specification and the like, sometimes the row direction is denoted as the X direction and the column direction is denoted as the Y direction. The X direction and the Y direction intersect, for example, perpendicularly.

[0232] Figure 5A An example is shown in which sub-pixels of different colors are arranged and configured in the X direction and sub-pixels of the same color are arranged and configured in the Y direction. Note that sub-pixels of different colors may also be arranged and configured in the Y direction and sub-pixels of the same color may be arranged and configured in the X direction.

[0233] A connection portion 140 and a region 141 may be provided outside the pixel portion 177. For example, the region 141 is preferably provided between the pixel portion 177 and the connection portion 140. The region 141 is provided with an organic compound layer 103. In addition, the connection portion 140 is provided with a conductive layer 151C.

[0234] Figure 5A An example is shown in which the region 141 and the connection portion 140 are located on the right side of the pixel portion 177, but the positions of the region 141 and the connection portion 140 are not particularly limited. In addition, the region 141 and the connection portion 140 may be one or more.

[0235] Figure 5B is an example of a cross-sectional view along the dash-dot line A1 - A2 in Figure 5A . As Figure 5B shown, the light-emitting device 1000 includes an insulating layer 171, a conductive layer 172 on the insulating layer 171, an insulating layer 173 on the insulating layer 171 and the conductive layer 172, an insulating layer 174 on the insulating layer 173, and an insulating layer 175 on the insulating layer 174. The insulating layer 171 is preferably provided on a substrate (not shown). The insulating layer 175, the insulating layer 174, and the insulating layer 173 are provided with openings reaching the conductive layer 172, and plugs 176 are provided in such a way as to be embedded in the openings.

[0236] In the pixel portion 177, a light-emitting device 130 is provided on the insulating layer 175 and the plugs 176. In addition, a protective layer 131 is provided so as to cover the light-emitting device 130. A substrate 120 is bonded to the protective layer 131 by a resin layer 122. Additionally, an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 may be provided between adjacent light-emitting devices 130.

[0237] Figure 5B A cross-section showing a plurality of inorganic insulating layers 125 and a plurality of insulating layers 127 is shown, but when looking down on the light-emitting device 1000, the inorganic insulating layer 125 and the insulating layer 127 are preferably formed as continuous single layers, respectively. That is, the insulating layer 127 is preferably an insulating layer having an opening portion on the pixel electrode.

[0238] In Figure 5B , light-emitting devices 130R, 130G, and 130B are shown as the light-emitting device 130. The light-emitting devices 130R, 130G, and 130B can emit light of different colors from each other. For example, the light-emitting device 130R can emit red light, the light-emitting device 130G can emit green light, and the light-emitting device 130B can emit blue light. Additionally, the light-emitting device 130R, 130G, or 130B can also emit other visible light or infrared light.

[0239] The light-emitting device according to one embodiment of the present invention can, for example, have a top emission structure that emits light in a direction opposite to the substrate on which the light-emitting device is formed. Additionally, the light-emitting device according to one embodiment of the present invention can also have a bottom emission structure.

[0240] The light-emitting device 130 has the structure shown in Embodiment 1. The light-emitting device 130R includes a pixel electrode 150R composed of a conductive layer 151R and a conductive layer 152R, an organic compound layer 103R on the pixel electrode 150R, and a common electrode 155 on the organic compound layer 103R. The light-emitting device 130G includes a pixel electrode 150G composed of a conductive layer 151G and a conductive layer 152G, an organic compound layer 103G on the pixel electrode 150G, and a common electrode 155 on the organic compound layer 103G. The light-emitting device 130B includes a pixel electrode 150B composed of a conductive layer 151B and a conductive layer 152B, an organic compound layer 103B on the pixel electrode 150B, and a common electrode 155 on the organic compound layer 103B.

[0241] The organic compound layer 103 includes at least a light-emitting layer and an electron injection layer, and may include other functional layers (such as a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron injection layer). In addition, a part of the organic compound layer 103 may be formed as a common layer. As the common layer, an electron transport layer or an electron injection layer can be used. In the case of using these layers as the common layer, after forming to the light-emitting layer, it is processed by photolithography, and the target layer (electron transport layer, electron injection layer) is deposited after the processing.

[0242] One of the pixel electrode 150 and the common electrode 155 included in the light-emitting device 130 is used as the anode, and the other is used as the cathode. Hereinafter, without special description, it is assumed that the pixel electrode 150 is used as the anode and the common electrode 155 is used as the cathode for explanation. The pixel electrode 150 corresponds to one of the first electrode 101 and the second electrode 102 described in Embodiment 1. The common electrode 155 corresponds to the other of the first electrode 101 and the second electrode 102 described in Embodiment 1.

[0243] The organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B are each formed or independently formed in an island shape for each emission color. By setting the organic compound layer 103 in an island shape for each light-emitting device 130, leakage current between adjacent light-emitting devices 130 can also be suppressed in a high-definition light-emitting device. Thereby, crosstalk can be prevented to realize a light-emitting device with extremely high contrast. In particular, a light-emitting device with high current efficiency at low brightness can be realized.

[0244] The organic compound layer 103 can also be provided in such a manner as to cover the top surface and the side surfaces of the pixel electrode 150 of the light-emitting device 130. Thus, compared with a structure in which the end portion of the organic compound layer 103 is located inside the end portion of the pixel electrode 150, it is easier to increase the aperture ratio of the light-emitting device 1000. In addition, by covering the side surfaces of the pixel electrode 150 of the light-emitting device 130 with the organic compound layer 103, contact between the pixel electrode 150 and the common electrode 155 can be suppressed, and thus short-circuiting of the light-emitting device 130 can be suppressed. Further, the distance between the light-emitting region of the organic compound layer 103 (i.e., the region overlapping with the pixel electrode 150) and the end portion of the organic compound layer 103 can be increased. Also, since the end portion of the organic compound layer 103 may be damaged during processing, by using a region far from the end portion of the organic compound layer 103 as the light-emitting region, the reliability of the light-emitting device 130 can be improved.

[0245] In addition, in a light-emitting device according to one embodiment of the present invention, the pixel electrode of the light-emitting device may also have a stacked structure. For example, in Figure 5B the example shown, the pixel electrode 150 of the light-emitting device 130 has a stacked structure of a conductive layer 151 and a conductive layer 152.

[0246] For example, when the light-emitting device 1000 has a top emission structure, preferably, the conductive layer 151 is a layer having a high visible light reflectance, and the conductive layer 152 is a layer having visible light transmissivity and a large work function. The higher the visible light reflectance of the pixel electrode 150, the more the extraction efficiency of the light emitted by the organic compound layer 103 can be improved. In addition, when the pixel electrode 150 is used as an anode, the larger the work function of the pixel electrode 150, the easier it is to inject holes into the organic compound layer 103. Therefore, by making the pixel electrode 150 of the light-emitting device 130 have a stacked structure of a conductive layer 151 having a high visible light reflectance and a conductive layer 152 having a large work function, the light-emitting device 130 can be made into a light-emitting device with high light extraction efficiency and low driving voltage.

[0247] Specifically, the visible light reflectance of the conductive layer 151 is preferably, for example, 40% or more and 100% or less, more preferably 70% or more and 100% or less. In addition, when the conductive layer 152 is an electrode having visible light transmissivity, the visible light transmittance is preferably, for example, 40% or more.

[0248] In addition, when removing a film deposited after forming a pixel electrode having a stacked structure by a wet etching method or the like, the chemical solution used for etching sometimes infiltrates into the structure. When the infiltrated chemical solution comes into contact with the pixel electrode, the pixel electrode may deteriorate due to galvanic corrosion or the like occurring between the multiple layers constituting the pixel electrode.

[0249] In view of this, it is preferable to form the conductive layer 152 so as to cover the top surface and the side surfaces of the conductive layer 151. By covering the conductive layer 151 with the conductive layer 152, the infiltrated liquid medicine does not come into contact with the conductive layer 151, thereby suppressing galvanic corrosion from occurring in the pixel electrode 150. Therefore, the light-emitting device 1000 can be manufactured by a method with a high yield, and thus an inexpensive light-emitting device can be realized. In addition, the occurrence of defects in the light-emitting device 1000 can be suppressed, so the light-emitting device 1000 can be a highly reliable light-emitting device.

[0250] As the conductive layer 151, for example, a metal material can be used. Specifically, for example, metals such as aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd), etc. and alloys obtained by appropriately combining them can be used.

[0251] As the conductive layer 152, an oxide containing any one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used. For example, it is preferable to use a conductive oxide containing any one or more of indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide containing gallium, titanium oxide, indium zinc oxide containing gallium, indium zinc oxide containing aluminum, indium tin oxide containing silicon, and indium zinc oxide containing silicon. In particular, the work function of indium tin oxide containing silicon is relatively large, and its work function is, for example, 4.0 eV or more, so it can be suitably used as the conductive layer 152.

[0252] In addition, each of the conductive layer 151 and the conductive layer 152 may also have a laminated structure including a plurality of layers containing different materials. In this case, the conductive layer 151 may also include a layer using a material such as a conductive oxide that can be used for the conductive layer 152, and the conductive layer 152 may also include a layer using a material such as a metal material that can be used for the conductive layer 151. For example, when the conductive layer 151 has a laminated structure of two or more layers, the layer in contact with the conductive layer 152 may be a layer containing the same material as the layer in contact with the conductive layer 151 in the conductive layer 152.

[0253] The end portion of the conductive layer 151 preferably has a tapered shape. Specifically, the end portion of the conductive layer 151 preferably has a tapered shape with a taper angle less than 90°. At this time, the conductive layer 152 provided along the side surface of the conductive layer 151 also has a tapered shape. By making the side surface of the conductive layer 152 have a tapered shape, the covering property of the organic compound layer 103 provided along the side surface of the conductive layer 152 can be improved.

[0254] In addition, in the case where the conductive layer 151 or the conductive layer 152 has a laminated structure, preferably, at least one of the laminated layers has a tapered shape. Further, in the laminated structure constituting each conductive layer, different tapered shapes may be provided for each layer.

[0255] In the present specification and the like, the tapered shape means a shape in which at least a part of the side surface of the component is inclined with respect to the substrate surface or the surface to be formed. For example, a region having an angle (hereinafter sometimes referred to as a taper angle) formed by the inclined side surface and the substrate surface of less than 90°. Note that the side surface and the substrate surface of the component do not necessarily have to be completely flat, and may be an approximately planar shape having a minute curvature or an approximately planar shape having fine irregularities.

[0256] Figure 6A This is a diagram when the conductive layer 151 has a laminated structure including a plurality of layers of different materials. As Figure 6A shown, the conductive layer 151 includes a conductive layer 151_1, a conductive layer 151_2 on the conductive layer 151_1, and a conductive layer 151_3 on the conductive layer 151_2. That is, Figure 6A the shown conductive layer 151 has a three-layer laminated structure. Thus, in the case where the conductive layer 151 has a laminated structure including a plurality of layers, it is sufficient that the visible light reflectance of at least one of the layers constituting the conductive layer 151 is higher than the visible light reflectance of the conductive layer 152.

[0257] In Figure 6A the shown example, the conductive layer 151_2 is sandwiched between the conductive layer 151_1 and the conductive layer 151_3. The conductive layer 151_1 and the conductive layer 151_3 are preferably made of a material that is less likely to deteriorate compared to the conductive layer 151_2. For example, the conductive layer 151_1 may be made of a material that is less likely to undergo migration due to contact with the insulating layer 175 compared to the conductive layer 151_2. Further, the conductive layer 151_3 may be made of a material that is less likely to be oxidized compared to the conductive layer 151_2; and the resistivity of its oxide is lower than that of the oxide of the material used for the conductive layer 151_2.

[0258] As described above, by adopting a structure in which the conductive layer 151_2 is sandwiched between the conductive layer 151_1 and the conductive layer 151_3, the range of choices for the material of the conductive layer 151_2 can be expanded. Thus, for example, the conductive layer 151_2 can be made into a layer having a visible light reflectance higher than at least one of the conductive layer 151_1 and the conductive layer 151_3. For example, aluminum can be used as the conductive layer 151_2. In addition, an aluminum-containing alloy can also be used as the conductive layer 151_2. In addition, titanium can be used as the conductive layer 151_1. Although the visible light reflectance of titanium is lower than that of aluminum, it is less likely to migrate compared to aluminum even when in contact with the insulating layer 175. And, titanium can be used as the conductive layer 151_3. Although the visible light reflectance of titanium is lower than that of aluminum, it is less likely to be oxidized compared to aluminum and the resistivity of the oxide is lower than the resistivity of aluminum oxide.

[0259] In addition, silver or a silver-containing alloy can also be used as the conductive layer 151_3. Silver has the characteristic of having a higher visible light reflectance than titanium. Moreover, silver is less likely to be oxidized compared to aluminum, and the resistivity of silver oxide is lower than the resistivity of aluminum oxide. Thus, when silver or a silver-containing alloy is used as the conductive layer 151_3, the visible light reflectance of the conductive layer 151 can be appropriately increased while suppressing an increase in the resistance of the pixel electrode 150 due to the oxidation of the conductive layer 151_2. Here, as the silver-containing alloy, for example, an alloy of silver, palladium, and copper (Ag-Pd-Cu, also denoted as APC) can be used. In addition, when silver or a silver-containing alloy is used as the conductive layer 151_3 and aluminum is used as the conductive layer 151_2, the visible light reflectance of the conductive layer 151_3 can be increased compared to the visible light reflectance of the conductive layer 151_2. Here, silver or a silver-containing alloy can also be used as the conductive layer 151_2. In addition, silver or a silver-containing alloy can also be used as the conductive layer 151_1.

[0260] On the other hand, the etch processability of a film using titanium is superior to that of a film using silver. Therefore, by using titanium as the conductive layer 151_3, the conductive layer 151_3 can be easily formed. In addition, the etch processability of a film using aluminum is also superior to that of a film using silver.

[0261] In this way, by making the conductive layer 151 have a stacked structure of multiple layers, the characteristics of the light-emitting device can be improved. For example, the light-emitting device 1000 can be made into a light-emitting device having high light extraction efficiency and high reliability.

[0262] Here, when the light-emitting device 130 adopts a microcavity structure, by using silver or a silver-containing alloy, which is a material with a high visible light reflectance, as the conductive layer 151_3, the light extraction efficiency of the light-emitting device 1000 can be appropriately increased.

[0263] In addition, as Figure 6AAs shown, depending on the material selection or processing method of the conductive layer 151, sometimes the side surface of the conductive layer 151_2 is located inside the side surface of the conductive layer 151_1, and a protrusion is formed in the conductive layer 151. This results in a decrease in the coverage of the conductive layer 152 over the conductive layer 151, and there is a possibility of disconnection of the conductive layer 152.

[0264] In view of this, it is preferable to provide the insulating layer 156 as Figure 6A shown. Figure 6A An example is shown in which the insulating layer 156 is provided on the conductive layer 151_1 so as to have a region overlapping with the side surface of the conductive layer 151_2. Thereby, disconnection or thinning of the conductive layer 152 due to the protrusion can be suppressed, and thus connection failure or an increase in driving voltage can be suppressed.

[0265] Note that although Figure 6A a structure is shown in which the entire side surface of the conductive layer 151_2 is covered with the insulating layer 156, a part of the side surface of the conductive layer 151_2 may not be covered with the insulating layer 156. The same applies to the pixel electrode 150 having the following structure, and a part of the side surface of the conductive layer 151_2 may not be covered with the insulating layer 156.

[0266] In addition, as Figure 6A shown, the insulating layer 156 preferably has a curved surface. Thereby, for example, compared with the case where the side surface of the insulating layer 156 on the conductive layer 152 side is perpendicular to the bottom surface of the insulating layer 175, disconnection in the conductive layer 152 covering the insulating layer 156 can be suppressed. Further, when the side surface of the insulating layer 156 on the conductive layer 152 side has a conical shape, specifically, a conical shape with a cone angle less than 90°, for example, compared with the case where the side surface of the insulating layer 156 on the conductive layer 152 side is perpendicular to the bottom surface of the insulating layer 175, disconnection in the conductive layer 152 covering the insulating layer 156 can be suppressed. Thereby, the light-emitting device 1000 can be manufactured by a method with a high yield. In addition, the occurrence of defects is suppressed, and the light-emitting device 1000 can be made into a highly reliable light-emitting device.

[0267] Note that one aspect of the present invention is not limited to this. For example, Figures 6B to 6D other structures of the pixel electrode 150 and the insulating layer 156 are shown. As described above, the pixel electrode 150 is composed of the conductive layer 151 and the conductive layer 152.

[0268] Figure 6B A structure is shown in which the insulating layer 156 covers not only the side surface of the conductive layer 151_2 but also the side surfaces of the conductive layer 151_1, the conductive layer 151_2, and the conductive layer 151_3.

[0269] Figure 6C A structure is shown in which the insulating layer 156 is not provided.

[0270] In Figure 6D this case, the conductive layer 151 does not have a laminated structure, and the conductive layer 152 has a laminated structure.

[0271] The conductive layer 152_1 is a layer having, for example, a higher adhesiveness to the conductive layer 152_2 than the insulating layer 175. As the conductive layer 152_1, for example, an oxide containing any one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used. For example, it is preferable to use any one or more of indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide containing gallium, titanium oxide, indium titanium oxide, zinc titanate, aluminum zinc oxide, indium zinc oxide containing gallium, indium zinc oxide containing aluminum, indium tin oxide containing silicon, and indium zinc oxide containing silicon, etc. as the conductive oxide. Thereby, film peeling of the conductive layer 152_2 can be suppressed. In addition, the conductive layer 152_2 can be made not to contact the insulating layer 175.

[0272] The conductive layer 152_2 is a layer having a higher visible light reflectance (for example, the reflectance of light at a specified wavelength in the range of 400 nm or more and less than 750 nm) than the conductive layer 151, the conductive layer 152_1, and the conductive layer 152_2. The visible light reflectance of the conductive layer 152_2 can be, for example, 70% or more and 100% or less, preferably 80% or more and 100% or less, more preferably 90% or more and 100% or less. In addition, for example, silver or a silver-containing alloy can be used as the conductive layer 152_2. As the silver-containing alloy, for example, an alloy of silver, palladium, and copper (APC) can be cited. Thereby, the light-emitting device 1000 can be made a light-emitting device with high light extraction efficiency. Note that a metal other than silver can also be used as the conductive layer 152_2.

[0273] When the conductive layer 151 and the conductive layer 152 are used as anodes, the conductive layer 152_1 is preferably a layer having a large work function. The conductive layer 152_3 is, for example, a layer having a larger work function than the conductive layer 152_2. As the conductive layer 152_3, for example, the same material as that which can be used for the conductive layer 152_1 can be used. For example, the same material can be used for the conductive layer 152_1 and the conductive layer 152_3.

[0274] Note that when the conductive layer 151 and the conductive layer 152 are used as cathodes, a layer having a small work function is preferable. The conductive layer 152_3 is, for example, a layer having a smaller work function than the conductive layer 152_2.

[0275] In addition, the conductive layer 152_3 is preferably a layer with a high visible light transmittance (e.g., the transmittance of light with a specified wavelength in the range of more than 400 nm and less than 750 nm). For example, the visible light transmittance of the conductive layer 152_3 is preferably higher than that of the conductive layer 151 and the conductive layer 152_2. For example, the visible light transmittance of the conductive layer 152_3 can be 60% or more and 100% or less, preferably 70% or more and 100% or less, and more preferably 80% or more and 100% or less. Thereby, the light absorbed by the conductive layer 152_3 in the light emitted by the organic compound layer 103 can be reduced. In addition, as described above, the conductive layer 152_2 under the conductive layer 152_3 can be a layer with a high visible light reflectance. Therefore, the light-emitting device 1000 can be made into a light-emitting device with high light extraction efficiency.

[0276] In Figure 6A a common layer 104 is provided between the organic compound layer 103 and the common electrode 155. Note that the common layer 104 may or may not be provided, but it is preferable to provide the common layer 104 because the damage to the organic compound layer 103 during processing can be reduced. When the common layer 104 is provided, the common layer 104 is preferably an electron injection layer. In addition, when the common layer 104 is provided, the stacked structure of the organic compound layer 103 and the common layer 104 corresponds to the organic compound layer 103 in Embodiment 1.

[0277] Next, an example of a manufacturing method of the light-emitting device 1000 having the structure shown in FIG. 5 will be described with reference to FIGS. 7 to 13.

[0278] [Example of Manufacturing Method 1] The thin films (insulating films, semiconductor films, conductive films, etc.) constituting the light-emitting device can be formed by sputtering, chemical vapor deposition (CVD: Chemical Vapor Deposition), vacuum evaporation, pulsed laser deposition (PLD: Pulsed Laser Deposition), or atomic layer deposition (ALD: Atomic Layer Deposition). As the CVD method, there are plasma-enhanced chemical vapor deposition (PECVD: Plasma Enhanced CVD) and thermal CVD. In addition, as one of the thermal CVD methods, there is metal organic chemical vapor deposition (MOCVD: Metal Organic CVD).

[0279] In addition, the thin films (insulating films, semiconductor films, conductive films, etc.) constituting the light-emitting device can be formed by wet deposition methods such as spin coating, dipping, spraying, inkjet, dispenser, screen printing, offset printing, doctor knife method, slot coating, roll coating, curtain coating, or knife coating.

[0280] In particular, when manufacturing a light-emitting device, vacuum processes such as vapor deposition methods and solution processes such as spin coating methods and inkjet methods can be utilized. As vapor deposition methods, physical vapor deposition methods (PVD methods) such as sputtering methods, ion plating methods, ion beam vapor deposition methods, molecular beam epitaxy methods, and vacuum evaporation methods, and chemical vapor deposition methods (CVD methods) can be cited. In particular, methods such as vapor deposition methods (such as vacuum evaporation methods), coating methods (dip coating methods, dye coating methods, bar coating methods, spin coating methods, spraying methods), printing methods (inkjet methods, screen printing (stencil printing) methods, offset printing (lithographic printing) methods, flexographic printing (letterpress printing) methods, gravure printing methods, or microcontact printing methods, etc.) can be used to form functional layers (hole injection layers, hole transport layers, hole blocking layers, light-emitting layers, electron blocking layers, electron transport layers, and electron injection layers, etc.) included in the organic compound layer.

[0281] In addition, when processing a thin film constituting a light-emitting device, for example, photolithography can be used for processing. Alternatively, nanoimprinting, sandblasting, lift-off, etc. can be used to process the thin film. In addition, island-shaped thin films can be directly formed by a deposition method using a masking mask such as a metal mask.

[0282] Typically, there are the following two methods for photolithography. One is a method of forming a resist mask on a thin film to be processed, processing the thin film by etching, for example, and removing the resist mask. The other is a method of depositing a photosensitive thin film and then performing exposure and development to process the thin film into a desired shape.

[0283] In the etching of a thin film, dry etching, wet etching, sandblasting, etc. can be utilized.

[0284] First, as Figure 7A shown, an insulating layer 171 is formed on a substrate (not shown). Next, a conductive layer 172 and a conductive layer 179 are formed on the insulating layer 171, and an insulating layer 173 is formed on the insulating layer 171 so as to cover the conductive layer 172 and the conductive layer 179. Next, an insulating layer 174 is formed on the insulating layer 173, and an insulating layer 175 is formed on the insulating layer 174.

[0285] As the substrate, a substrate having at least heat resistance capable of withstanding subsequent heat treatment can be used. In the case of using an insulating substrate as the substrate, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, or an organic resin substrate, etc. can be used. In addition, a single-crystalline semiconductor substrate or a polycrystalline semiconductor substrate made of silicon or silicon carbide, etc., a compound semiconductor substrate made of silicon germanium, etc., an SOI substrate, etc. can also be used.

[0286] Next, as Figure 7AAs shown, openings reaching the conductive layer 172 are formed in the insulating layer 175, insulating layer 174, and insulating layer 173. Then, a plug 176 is formed in such a way as to embed in the openings.

[0287] Then, as Figure 7A shown, a conductive film 151f which will later become the conductive layers 151R, 151G, 151B, and 151C is formed on the plug 176 and the insulating layer 175. The conductive film 151f can be formed, for example, by a sputtering method or a vacuum evaporation method. In addition, a metal material can be used as the conductive film 151f, for example.

[0288] Then, as Figure 7A shown, a resist mask 191 is formed on the conductive film 151f, for example. The resist mask 191 can be formed by applying a photosensitive material (photoresist) and then performing exposure and development.

[0289] Then, as Figure 7B shown, for example, using an etching method, specifically a dry etching method, the conductive film 151f in the region not overlapping with the resist mask 191 is removed. Note that in the case where the conductive film 151f includes a layer using a conductive oxide such as indium tin oxide, the layer can also be removed by a wet etching method. Thus, the conductive layers 151R, 151G, 151B, and 151C are formed. Note that, for example, when removing a part of the conductive film 151f by a dry etching method, recesses (also referred to as depressions) sometimes form in the region of the insulating layer 175 that does not overlap with the conductive layer 151.

[0290] Then, as Figure 7C shown, the resist mask 191 is removed. The resist mask 191 can be removed, for example, by ashing using oxygen plasma. Or, oxygen gas and CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or a Group 18 element such as He can also be used. Or, the resist mask 191 can be removed by wet etching.

[0291] Then, as Figure 7D shown, an insulating film 156f which will later become the insulating layers 156R, 156G, 156B, and 156C is formed on the conductive layers 151R, 151G, 151B, 151C, and the insulating layer 175. The insulating film 156f can be formed, for example, by a CVD method, an ALD method, a sputtering method, or a vacuum evaporation method.

[0292] The insulating film 156f can be made of an inorganic material. As the insulating film 156f, for example, an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitrogen oxide insulating film can be used. For example, as the insulating film 156f, an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitrogen oxide insulating film containing silicon can be used. For example, silicon oxynitride can be used as the insulating film 156f.

[0293] Next, as Figure 7E shown, by processing the insulating film 156f, an insulating layer 156R, an insulating layer 156G, an insulating layer 156B, and an insulating layer 156C are formed. For example, by etching the top surface of the insulating film 156f substantially uniformly, the insulating layer 156 can be formed. The process of etching uniformly in this way for planarization is also called an etch-back process. In addition, the insulating layer 156 can also be formed by photolithography.

[0294] Next, as Figure 8A shown, a conductive film 152f that will later become the conductive layers 152R, 152G, 152B, and 152C is formed on the conductive layers 151R, 151G, 151B, 151C, the insulating layers 156R, 156G, 156B, 156C, and the insulating layer 175. Specifically, for example, the conductive film 152f is formed so as to cover the conductive layers 151R, 151G, 151B, 151C, the insulating layers 156R, 156G, 156B, and 156C.

[0295] The conductive film 152f can be formed, for example, by sputtering or vacuum evaporation. In addition, the conductive film 152f can be formed by ALD. In addition, for example, a conductive oxide can be used as the conductive film 152f. Or, as the conductive film 152f, a laminated structure of a film using a metal material and a film using a conductive oxide on this film can be adopted. For example, as the conductive film 152f, a laminated structure of a film using titanium, silver, or an alloy containing silver and a film using a conductive oxide on this film can be adopted.

[0296] Next, as Figure 8B shown, for example, the conductive film 152f is processed by photolithography, whereby the conductive layers 152R, 152G, 152B, and 152C are formed. Specifically, for example, after forming a resist mask, a part of the conductive film 152f is removed by etching. The conductive film 152f can be removed, for example, by wet etching. Note that the conductive film 152f can also be removed by dry etching. Through the above processes, a pixel electrode 150 including the conductive layer 151 and the conductive layer 152 is formed.

[0297] Next, preferably, a hydrophobization treatment is performed on the conductive layer 152. Through the hydrophobization treatment, the surface state of the object to be treated can be changed from hydrophilic to hydrophobic, or the hydrophobicity of the surface of the object to be treated can be improved. By performing the hydrophobization treatment on the conductive layer 152, the adhesion between the conductive layer 152 and the organic compound layer 103 to be formed in the subsequent process can be improved to suppress film peeling. Note that the hydrophobization treatment may not be performed.

[0298] Next, as Figure 8C shown, an organic compound film 103Bf that will later become the organic compound layer 103B is formed on the conductive layer 152R, the conductive layer 152G, the conductive layer 152B, and the insulating layer 175.

[0299] In the present invention, the organic compound film 103Bf includes a plurality of organic compound layers each having at least one light-emitting layer. For the specific content, reference can be made to the structure of the light-emitting device 130 described in Embodiment 1. In addition, a structure in which a plurality of organic compound layers each having at least one light-emitting layer are stacked with an intermediate layer therebetween can also be employed.

[0300] As Figure 8C shown, the organic compound film 103Bf is not formed on the conductive layer 152C. For example, by using a mask for defining the deposition range (also referred to as a region mask or a coarse metal mask, etc. to distinguish it from a fine metal mask), the organic compound film 103Bf can be deposited only in a desired region. By adopting a deposition process using a region mask and a processing process using a resist mask, a light-emitting device can be manufactured with a relatively simple process.

[0301] The organic compound film 103Bf can be formed, for example, by a vapor deposition method, and specifically, by a vacuum vapor deposition method. In addition, the organic compound film 103Bf can also be formed by methods such as a transfer method, a printing method, an inkjet method, or a coating method.

[0302] Next, as Figure 8D shown, a sacrificial film 158Bf that will later become the sacrificial layer 158B and a mask film 159Bf that will later become the mask layer 159B are sequentially formed on the organic compound film 103Bf.

[0303] The sacrificial film 158Bf and the mask film 159Bf can be formed, for example, by a sputtering method, an ALD method (thermal ALD method, PEALD method), a CVD method, or a vacuum vapor deposition method. In addition, they can also be formed by the above-mentioned wet deposition methods.

[0304] In addition, the sacrificial film 158Bf and the mask film 159Bf are formed at a temperature lower than the heat-resistant temperature of the organic compound film 103Bf. The substrate temperature when forming the sacrificial film 158Bf and the mask film 159Bf is typically 200 °C or lower, preferably 150 °C or lower, more preferably 120 °C or lower, further preferably 100 °C or lower, and even more preferably 80 °C or lower.

[0305] Note that, in the present embodiment, an example in which the mask film is composed of a two-layer structure of the sacrificial film 158Bf and the mask film 159Bf is shown, but the mask film may have a single-layer structure or a laminated structure of three or more layers.

[0306] By providing a sacrificial layer on the organic compound film 103Bf, damage to the organic compound film 103Bf during the manufacturing process of the light-emitting device can be reduced, and the reliability of the light-emitting device can be improved.

[0307] As the sacrificial film 158Bf, a film with high resistance to the processing conditions of the organic compound film 103Bf is used. Specifically, a film with a large etching selectivity ratio with respect to the organic compound film 103Bf is used. As the mask film 159Bf, a film with a large etching selectivity ratio with respect to the sacrificial film 158Bf is used.

[0308] As the sacrificial film 158Bf and the mask film 159Bf, a film that can be removed by wet etching is preferably used. By using wet etching, damage to the organic compound film 103Bf during the processing of the sacrificial film 158Bf and the mask film 159Bf can be reduced compared to the case of using dry etching.

[0309] When using wet etching, an acidic chemical solution is particularly preferably used. As the acidic chemical solution, a chemical solution containing any one of phosphoric acid, hydrofluoric acid, nitric acid, acetic acid, oxalic acid, and sulfuric acid, etc., or a mixed chemical solution containing two or more acids (also referred to as a mixed acid) can be used.

[0310] As the sacrificial film 158Bf and the mask film 159Bf, for example, one or more of a metal film, an alloy film, a metal oxide film, a semiconductor film, an organic insulating film, and an inorganic insulating film, etc., can be used.

[0311] In addition, by using a film containing a material having ultraviolet light-shielding properties as the sacrificial film 158Bf and the mask film 159Bf, for example, ultraviolet light can be prevented from irradiating the organic compound layer during the exposure process. By suppressing damage to the organic compound layer caused by ultraviolet light, the reliability of the light-emitting device can be improved.

[0312] Note that the same effect is also produced when a film containing a material having ultraviolet light-shielding properties is used as the material of the inorganic insulating film 125f described later.

[0313] As the sacrificial film 158Bf and the mask film 159Bf, for example, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloy materials containing such metal materials can be used respectively. Low melting point materials such as aluminum or silver are particularly preferably used.

[0314] In addition, as the sacrificial film 158Bf and the mask film 159Bf, metal oxides such as In-Ga-Zn oxide, indium oxide, In-Zn oxide, In-Sn oxide, indium-titanium oxide (In-Ti oxide), indium-tin-zinc oxide (In-Sn-Zn oxide), indium-titanium-zinc oxide (In-Ti-Zn oxide), indium-gallium-tin-zinc oxide (In-Ga-Sn-Zn oxide), or indium-tin oxide containing silicon can be used respectively.

[0315] Note that an element M (M is one or more selected from aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) can also be used instead of the above-mentioned gallium.

[0316] As the sacrificial film 158Bf and the mask film 159Bf, for example, semiconductor materials such as silicon or germanium are used. This has a high affinity with the semiconductor manufacturing process, so it is preferred. Alternatively, oxides or nitrides of the above semiconductor materials can be used. Alternatively, non-metal materials such as carbon or their compounds can be used. In addition, metals such as titanium, tantalum, tungsten, chromium, and aluminum, or alloys containing one or more of them can be used. In addition, oxides containing the above metals such as titanium oxide or chromium oxide, or nitrides such as titanium nitride, chromium nitride, or tantalum nitride can be used.

[0317] In addition, as the sacrificial film 158Bf and the mask film 159Bf, various inorganic insulating films can be used respectively. In particular, the adhesion of the oxide insulating film to the organic compound film 103Bf is higher than that of the nitride insulating film to the organic compound film 103Bf, so it is preferred. For example, inorganic insulating materials such as aluminum oxide, hafnium oxide, or silicon oxide can be used for the sacrificial film 158Bf and the mask film 159Bf respectively. As the sacrificial film 158Bf and the mask film 159Bf, an aluminum oxide film can be formed by ALD method respectively. By using the ALD method, the damage to the substrate (especially to the organic compound layer) can be reduced, so it is preferred.

[0318] As one or both of the sacrificial film 158Bf and the mask film 159Bf, an organic material may also be used. For example, as the organic material, a material that can be dissolved in a solvent that is at least chemically stable to the film located at the uppermost part of the organic compound film 103Bf may be used. In particular, a material that can be dissolved in water or alcohol may be appropriately used. When depositing the above material, it is preferable to coat the material by a wet deposition method in a state where the material is dissolved in a solvent such as water or alcohol, and then perform a heat treatment for evaporating the solvent. At this time, it is preferable to perform the heat treatment in a reduced-pressure atmosphere, whereby the solvent can be removed at a low temperature and in a short time, and the thermal damage to the organic compound film 103Bf can be reduced.

[0319] As the sacrificial film 158Bf and the mask film 159Bf, organic resins such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerol, pullulan, water-soluble cellulose, a polyamide resin soluble in alcohol, or a fluororesin such as a perfluoropolymer may also be used.

[0320] For example, as the sacrificial film 158Bf, an organic film (for example, a PVA film) formed by any one of vapor deposition and the above wet deposition method may be used, and as the mask film 159Bf, an inorganic film (for example, a silicon nitride film) formed by sputtering may be used.

[0321] Next, as shown in Figure 8D , a resist mask 190B is formed on the mask film 159Bf. The resist mask 190B can be formed by coating a photosensitive material (photoresist) and performing exposure and development.

[0322] The resist mask 190B can use a positive resist material or a negative resist material.

[0323] The resist mask 190B is provided at a position overlapping with the conductive layer 152B. The resist mask 190B is preferably also provided at a position overlapping with the conductive layer 152C. Thereby, damage to the conductive layer 152C during the manufacturing process of the light-emitting device can be suppressed. Note that the resist mask 190B may not be provided on the conductive layer 152C. In addition, as shown in the cross-sectional view along B1-B2 in Figure 8C , the resist mask 190B is preferably provided so as to cover the end portion of the organic compound film 103Bf to the end portion of the conductive layer 152C (the end portion on the organic compound film 103Bf side).

[0324] Next, as shown in Figure 8EAs shown, a part of the mask film 159Bf is removed using the resist mask 190B to form the mask layer 159B. The mask layer 159B remains on the conductive layer 152B and the conductive layer 152C. Then, the resist mask 190B is removed. Next, the mask layer 159B is used as a mask (also referred to as a hard mask) to remove a part of the sacrificial film 158Bf to form the sacrificial layer 158B.

[0325] The sacrificial film 158Bf and the mask film 159Bf can be processed by a wet etching method or a dry etching method, respectively. The processing of the sacrificial film 158Bf and the mask film 159Bf is preferably performed by wet etching.

[0326] By using the wet etching method, compared with the case of using the dry etching method, the damage to the organic compound film 103Bf during the processing of the sacrificial film 158Bf and the mask film 159Bf can be reduced. When using the wet etching method, for example, it is preferable to use a developing solution, an aqueous solution of tetramethylammonium hydroxide (TMAH), dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a liquid medicine such as a mixed liquid thereof. In addition, when using the wet etching method, a mixed acid liquid medicine containing water, phosphoric acid, dilute hydrofluoric acid, and nitric acid can also be used. Note that the liquid medicine used for the wet etching treatment can be alkaline or acidic.

[0327] Since the organic compound film 103Bf is not exposed during the processing of the mask film 159Bf, the range of selection of the processing method is wider compared with the case of processing the sacrificial film 158Bf. Specifically, when processing the mask film 159Bf, even if an oxygen-containing gas is used as the etching gas, the deterioration of the organic compound film 103Bf can be further suppressed.

[0328] When using the wet etching method, it is particularly preferable to use an acidic liquid medicine. As the acidic liquid medicine, a liquid medicine containing any one of phosphoric acid, hydrofluoric acid, nitric acid, acetic acid, oxalic acid, and sulfuric acid, or a mixed liquid medicine containing two or more acids (also referred to as a mixed acid) can be used.

[0329] In addition, when using the dry etching method in the processing of the sacrificial film 158Bf, the deterioration of the organic compound film 103Bf can be suppressed by not using an oxygen-containing gas as the etching gas. In the case of using the dry etching method, for example, it is preferable to use a gas containing CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or a Group 18 element gas such as He as the etching gas.

[0330] The resist mask 190B can be removed by the same method as the resist mask 191. At this time, since the sacrificial film 158Bf is located on the outermost surface and the organic compound film 103Bf is not exposed, damage to the organic compound film 103Bf during the removal process of the resist mask 190B can be suppressed. In addition, the range of selection of the removal method of the resist mask 190B can be expanded.

[0331] Next, as Figure 8E shown, the organic compound film 103Bf is processed to form the organic compound layer 103B. For example, the mask layer 159B and the sacrificial layer 158B are used as hard masks to remove a part of the organic compound film 103Bf, thereby forming the organic compound layer 103B.

[0332] Thus, as Figure 8E shown, a stacked structure of the organic compound layer 103B, the sacrificial layer 158B, and the mask layer 159B remains on the conductive layer 152B. In addition, the conductive layer 152R and the conductive layer 152G are exposed.

[0333] The processing of the organic compound film 103Bf can be carried out by dry etching or wet etching. For example, when dry etching is used for processing, an etching gas containing oxygen can be used. When the etching gas contains oxygen, the etching rate can be increased. Therefore, etching can be carried out under low power conditions while maintaining a sufficient etching rate. Therefore, damage to the organic compound film 103Bf can be suppressed. Also, defects such as the adhesion of reaction products generated during etching can be suppressed.

[0334] Alternatively, an etching gas not containing oxygen can also be used. For example, by using an etching gas not containing oxygen, deterioration of the organic compound film 103Bf can be suppressed.

[0335] As described above, in one aspect of the present invention, the mask layer 159B is formed by forming the resist mask 190B on the mask film 159Bf and removing a part of the mask film 159Bf using the resist mask 190B. Then, the organic compound layer 103B is formed by using the mask layer 159B as a mask to remove a part of the organic compound film 103Bf. Therefore, it can be said that the organic compound layer 103B is formed by processing the organic compound film 103Bf using photolithography. Alternatively, a part of the organic compound film 103Bf can be removed using the resist mask 190B. Then, the resist mask 190B can also be removed.

[0336] Here, a hydrophobization treatment of the conductive layer 152G can be carried out as needed. When processing the organic compound film 103Bf, for example, the surface state of the conductive layer 152G sometimes becomes hydrophilic. By carrying out the hydrophobization treatment of the conductive layer 152G, for example, the adhesion between the conductive layer 152G and a layer to be formed in a later process (here, the organic compound layer 103G) can be improved to suppress film peeling.

[0337] Next, as Figure 9AAs shown, an organic compound film 103Gf that will later become the organic compound layer 103G is formed on the conductive layer 152R, the conductive layer 152G, the mask layer 159B, and the insulating layer 175.

[0338] The organic compound film 103Gf can be formed in the same manner as the method that can be used when forming the organic compound film 103Bf. Additionally, the organic compound film 103Gf can have the same structure as the organic compound film 103Bf.

[0339] Next, as Figure 9B shown, a sacrificial film 158Gf that will later become the sacrificial layer 158G and a mask film 159Gf that will later become the mask layer 159G are sequentially formed on the organic compound film 103Gf and the mask layer 159B. Then, a resist mask 190G is formed. The materials and formation methods of the sacrificial film 158Gf and the mask film 159Gf are the same as the conditions that can be used for the sacrificial film 158Bf and the mask film 159Bf. The materials and formation methods of the resist mask 190G are the same as the conditions that can be applied to the resist mask 190B.

[0340] The resist mask 190G is disposed at a position overlapping with the conductive layer 152G.

[0341] Next, as Figure 9C shown, a part of the mask film 159Gf is removed using the resist mask 190G, thereby forming the mask layer 159G. The mask layer 159G remains on the conductive layer 152G. Then, the resist mask 190G is removed. Next, using the mask layer 159G as a mask, a part of the sacrificial film 158Gf is removed, thereby forming the sacrificial layer 158G. Next, the organic compound film 103Gf is processed to form the organic compound layer 103G. For example, using the mask layer 159G and the sacrificial layer 158G as a hard mask, a part of the organic compound film 103Gf is removed to form the organic compound layer 103G.

[0342] Thus, as Figure 9C shown, a stacked structure of the organic compound layer 103G, the sacrificial layer 158G, and the mask layer 159G remains on the conductive layer 152G. In addition, the mask layer 159B and the conductive layer 152R are exposed.

[0343] Additionally, for example, a hydrophobization treatment of the conductive layer 152R can also be performed.

[0344] Next, as Figure 10A shown, an organic compound film 103Rf that will later become the organic compound layer 103R is formed on the conductive layer 152R, the mask layer 159G, the mask layer 159B, and the insulating layer 175.

[0345] The organic compound film 103Rf can be formed using the same method as that which can be used to form the organic compound film 103Bf. In addition, the organic compound film 103Rf can have the same structure as the organic compound film 103Bf.

[0346] Next, as Figure 10B shown, a sacrificial film 158Rf that will later become the sacrificial layer 158R and a mask film 159Rf that will later become the mask layer 159R are sequentially formed on the organic compound film 103Rf and the mask layer 159B. Then, a resist mask 190R is formed. The materials and formation methods of the sacrificial film 158Rf and the mask film 159Rf are the same as the conditions that can be used for the sacrificial film 158Bf and the mask film 159Bf. The materials and formation methods of the resist mask 190R are the same as the conditions that can be applied to the resist mask 190B.

[0347] The resist mask 190R is provided at a position overlapping with the conductive layer 152R.

[0348] Next, as Figure 10C shown, a part of the mask film 159Rf is removed using the resist mask 190R, thereby forming the mask layer 159R. The mask layer 159R remains on the conductive layer 152R. Then, the resist mask 190R is removed. Next, a part of the sacrificial film 158Rf is removed using the mask layer 159R as a mask, thereby forming the sacrificial layer 158R. Next, the organic compound film 103Rf is processed to form the organic compound layer 103R. For example, the mask layer 159R and the sacrificial layer 158R are used as hard masks and a part of the organic compound film 103Rf is removed, thereby forming the organic compound layer 103R.

[0349] Thus, as Figure 10C shown, a stacked structure of the organic compound layer 103R, the sacrificial layer 158R, and the mask layer 159R remains on the conductive layer 152R. In addition, the mask layer 159B is exposed.

[0350] Note that the sides of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B are each preferably perpendicular or substantially perpendicular to the formation surface. For example, the angle formed by the formation surface and these sides is preferably 60° or more and 90° or less.

[0351] As described above, the distance between two adjacent layers among the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B formed by photolithography can be reduced to less than 8 μm, less than 5 μm, less than 3 μm, less than 2 μm, or less than 1 μm. Here, for example, this distance can be defined based on the distance between the opposing ends of two adjacent ones among the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B. In this way, by reducing the distance between the island-shaped organic compound layers, a light-emitting device with high clarity and a large aperture ratio can be provided. In addition, the distance between the pixel electrodes 150 between adjacent light-emitting devices can be reduced, for example, to less than 10 μm, less than 8 μm, less than 5 μm, less than 3 μm, or less than 2 μm. Note that the distance between the pixel electrodes 150 between adjacent light-emitting devices is preferably 2 μm or more and 5 μm or less.

[0352] Next, as Figure 11A shown, the mask layer 159R, the mask layer 159G, and the mask layer 159B are removed.

[0353] Note that, although the case where the mask layer 159R, the mask layer 159G, and the mask layer 159B are removed is described as an example in this embodiment, the mask layer 159R, the mask layer 159G, and the mask layer 159B may not be removed. For example, when the mask layer 159R, the mask layer 159G, and the mask layer 159B contain the above-described material having ultraviolet light-shielding properties, by not removing the above mask layer and proceeding to the next process, the organic compound layer can be protected from light irradiation (including illumination light).

[0354] As the process for removing the mask layer, the same method as the process for processing the mask layer can be used. In particular, by using a wet etching method, compared with the case of using a dry etching method, the damage to the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B during the removal of the mask layer can be reduced.

[0355] Alternatively, the mask layer can be removed by dissolving it in a solvent such as water or alcohol. As the alcohol, ethanol, methanol, isopropyl alcohol (IPA), or glycerol, etc. can be cited.

[0356] After removing the mask layer, a drying process may also be performed to remove the water contained in the organic compound layers 103R, 103G, and 103B, and the water adsorbed on the surfaces of the organic compound layers 103R, 103G, and 103B. For example, heat treatment may also be performed in an inert atmosphere or a reduced-pressure atmosphere. The heat treatment may be performed at a substrate temperature of 50°C or higher and 200°C or lower, preferably 60°C or higher and 150°C or lower, and more preferably 70°C or higher and 120°C or lower. By employing a reduced-pressure atmosphere, drying can be performed at a lower temperature, so it is preferred.

[0357] Next, as Figure 11B shown, an inorganic insulating film 125f that will later become the inorganic insulating layer 125 is formed so as to cover the organic compound layers 103R, 103G, 103B, the sacrificial layers 158R, 158G, and 158B.

[0358] As described later, an insulating film that will later become the insulating layer 127 is formed in contact with the top surface of the inorganic insulating film 125f. Therefore, the top surface of the inorganic insulating film 125f is preferably highly compatible with the material (e.g., a photosensitive resin composition containing an acrylic resin) of the insulating film that will become the insulating layer 127. To improve this compatibility, the top surface of the inorganic insulating film 125f may be surface-treated. Specifically, it is preferred to hydrophobize (or increase its hydrophobicity) the top surface of the inorganic insulating film 125f. For example, it is preferred to perform treatment using a silylating agent such as hexamethyldisilazane (HMDS). By hydrophobizing the top surface of the inorganic insulating film 125f in this way, the insulating film 127f can be formed with high adhesion.

[0359] Next, as Figure 11C shown, an insulating film 127f that will later become the insulating layer 127 is formed on the inorganic insulating film 125f.

[0360] The inorganic insulating film 125f and the insulating film 127f are preferably deposited by a formation method that causes less damage to the organic compound layers 103R, 103G, and 103B. In particular, since the inorganic insulating film 125f is formed in contact with the sides of the organic compound layers 103R, 103G, and 103B, the inorganic insulating film 125f is preferably deposited by a formation method that causes less damage to the organic compound layers 103R, 103G, and 103B than when depositing the insulating film 127f.

[0361] In addition, the inorganic insulating film 125f and the insulating film 127f are each formed at a temperature lower than the heat-resistant temperature of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B. By increasing the substrate temperature during deposition, an inorganic insulating film 125f with a low impurity concentration and a high barrier property against at least one of water and oxygen can be formed even if its thickness is thin.

[0362] The substrate temperature during the formation of the inorganic insulating film 125f and the insulating film 127f is each preferably 60°C or higher, 80°C or higher, 100°C or higher, or 120°C or higher and 200°C or lower, 180°C or lower, 160°C or lower, 150°C or lower, or 140°C or lower.

[0363] As the inorganic insulating film 125f, it is preferable to form an insulating film with a thickness of 3 nm or more, 5 nm or more, or 10 nm or more and 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less within the above substrate temperature range.

[0364] The inorganic insulating film 125f is preferably formed by, for example, the ALD method. By using the ALD method, deposition damage can be reduced, and a film with high coverage can be deposited, so it is preferable. As the inorganic insulating film 125f, it is preferable to form an aluminum oxide film by the ALD method, for example.

[0365] In addition to this, the inorganic insulating film 125f can also be formed by a sputtering method, a CVD method, or a PECVD method with a deposition rate higher than that of the ALD method. Thereby, a light-emitting device with high reliability can be manufactured with high productivity.

[0366] The insulating film 127f is preferably formed by the above wet deposition method. The insulating film 127f is preferably formed by spin coating using a photosensitive material, and more specifically, it is preferably formed using a photosensitive resin composition containing an acrylic resin.

[0367] For example, it is preferable to form the insulating film 127f using a resin composition containing a polymer, an acid generator, and a solvent. The polymer is formed using one or more monomers and has a structure in which one or more structural units (also referred to as constituent units) are repeated regularly or irregularly. As the acid generator, one or both of a compound that generates an acid by irradiating light and a compound that generates an acid by heating can be used. The resin composition may further contain one or more of a photosensitizer, a sensitizer, a catalyst, an adhesion aid, a surfactant, and an antioxidant.

[0368] In addition, it is preferable to perform a heat treatment (also referred to as pre-baking) after forming the insulating film 127f. This heat treatment is performed at a temperature lower than the heat-resistant temperature of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B. The substrate temperature during the heat treatment is preferably 50°C or higher and 200°C or lower, more preferably 60°C or higher and 150°C or lower, and still more preferably 70°C or higher and 120°C or lower. Thereby, the solvent in the insulating film 127f can be removed.

[0369] Next, exposure is performed to sensitize a part of the insulating film 127f with visible light or ultraviolet light. Here, when a positive photosensitive resin composition containing an acrylic resin is used for the insulating film 127f, visible light or ultraviolet light is irradiated to the region where the insulating layer 127 will not be formed in the subsequent process. The insulating layer 127 is formed in the region sandwiched between any two of the conductive layers 152R, the conductive layer 152G, and the conductive layer 152B and around the conductive layer 152C. Therefore, visible light or ultraviolet light is irradiated to the conductive layers 152R, the conductive layer 152G, the conductive layer 152B, and the conductive layer 152C. Note that when a negative photosensitive material is used for the insulating film 127f, visible light or ultraviolet light is irradiated to the region where the insulating layer 127 will be formed.

[0370] By means of the region exposed to the insulating film 127f, the width of the insulating layer 127 to be formed later can be controlled. In the present embodiment, processing is performed such that the insulating layer 127 has a portion overlapping with the top surface of the conductive layer 151.

[0371] Here, by providing an oxygen barrier insulating layer (such as an alumina film, etc.) as one or both of the sacrificial layer 158 (sacrificial layer 158R, sacrificial layer 158G, and sacrificial layer 158B) and the inorganic insulating film 125f, oxygen diffusion into the organic compound layer 103 (organic compound layer 103R, organic compound layer 103G, and organic compound layer 103B) can be reduced. When light (visible light or ultraviolet light) irradiates the organic compound layer 103, the organic compounds contained in the organic compound layer 103 sometimes become excited states, promoting the reaction with oxygen in the atmosphere. More specifically, when light (visible light or ultraviolet light) irradiates the organic compound layer 103 in an oxygen-containing atmosphere, oxygen may bond to the organic compounds contained in the organic compound layer 103. By providing the sacrificial layer 158 and the inorganic insulating film 125f on the island-shaped organic compound layer 103, oxygen in the atmosphere bonding to the organic compounds contained in the organic compound layer 103 can be reduced.

[0372] Next, as Figure 12AAs shown, the exposed areas in the insulating film 127f are developed and removed to form the insulating layer 127a. The insulating layer 127a is formed in the areas sandwiched by any two of the conductive layers 152R, 152G, and 152B and in the area surrounding the conductive layer 152C. Here, when an acrylic resin is used for the insulating film 127f, an alkaline solution can be used as the developer. For example, an aqueous TMAH solution can be used.

[0373] Next, as Figure 12B shown, the insulating layer 127a is used as a mask for an etching process to remove a part of the inorganic insulating film 125f and reduce the thickness of a part of the sacrificial layer 158. Thereby, an inorganic insulating layer 125 is formed under the insulating layer 127a. Hereinafter, the etching process of processing the inorganic insulating film 125f using the insulating layer 127a as a mask is sometimes referred to as the first etching process.

[0374] In other words, in the first etching process, the etching process is stopped in a state where the thickness is reduced without completely removing the sacrificial layer 158. Thus, by leaving the sacrificial layer 158 on the organic compound layer 103, damage to the organic compound layer 103 can be prevented during the processing of subsequent processes.

[0375] The first etching process can be performed by dry etching or wet etching. When the inorganic insulating film 125f is deposited using the same material as the sacrificial layer 158, the processing of the inorganic insulating film 125f and the thinning of the exposed sacrificial layer 158 can be performed at once by the first etching process, so it is preferable.

[0376] By using the insulating layer 127a having a tapered side shape as a mask for etching, the side surface of the inorganic insulating layer 125 and the upper end portion of the side surface of the sacrificial layer 158 can be easily made into a tapered shape.

[0377] For example, when the first etching process is performed by dry etching, a chlorine-based gas can be used. As the chlorine-based gas, one gas such as Cl2, BCl3, SiCl4, or CCl4 or a mixture of two or more of the above gases can be used. In addition, one gas such as oxygen gas, hydrogen gas, helium gas, or argon gas or a mixture of two or more of the above gases can be appropriately added to the above chlorine-based gas. By using dry etching, a region with a small film thickness of the sacrificial layer 158 can be formed with excellent in-plane uniformity.

[0378] In addition, for example, the first etching process can be performed by wet etching. By using the wet etching method, the damage to the organic compound layer 103 can be reduced compared to the case of using the dry etching method.

[0379] In wet etching, an acidic chemical solution is preferably used. As the acidic chemical solution, a chemical solution containing any one of phosphoric acid, hydrofluoric acid, nitric acid, acetic acid, oxalic acid, sulfuric acid, etc., or a mixed chemical solution of two or more acids (also referred to as mixed acid) can be used.

[0380] In addition, a basic solution can be used for wet etching. For example, an aqueous TMAH solution as a basic solution can be used in the wet etching of an alumina film. At this time, wet etching can be performed in a photoresist coating manner.

[0381] Next, a heat treatment (also referred to as post-baking) is performed. By performing the heat treatment, the insulating layer 127a can be deformed into an insulating layer 127 having a tapered shape on its side surface (refer to Figure 12C ). This heat treatment is performed at a temperature lower than the heat-resistant temperature of the organic compound layer 103. The heat treatment can be performed at a substrate temperature of 50°C or higher and 200°C or lower, preferably 60°C or higher and 150°C or lower, and more preferably 70°C or higher and 130°C or lower. The heating atmosphere can be either an air atmosphere or an inert atmosphere. In addition, the heating atmosphere can be either an air atmosphere or a reduced-pressure atmosphere. In the heat treatment of this step, it is preferable to increase the substrate temperature compared to the heat treatment (pre-baking) after forming the insulating film 127f.

[0382] By the heat treatment, the adhesion between the insulating layer 127 and the inorganic insulating layer 125 can be improved, and the corrosion resistance of the insulating layer 127 can also be improved. In addition, by deforming the insulating layer 127a, a shape in which the end portion of the inorganic insulating layer 125 is covered by the insulating layer 127 can be achieved.

[0383] By leaving the sacrificial layer 158 in a reduced-thickness state without completely removing it in the first etching process, damage and deterioration of the organic compound layer 103 can be prevented during this heat treatment. Thereby, the reliability of the light-emitting device can be improved.

[0384] Next, as Figure 13A shown, an etching process is performed using the insulating layer 127 as a mask to remove a part of the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B. Note that, at this time, a part of the inorganic insulating layer 125 may also be removed. Through this etching process, openings are formed in the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B, and the top surfaces of the organic compound layer 103R, the organic compound layer 103G, the organic compound layer 103B, and the conductive layer 152C are exposed from the openings. Hereinafter, the etching process of using the insulating layer 127 as a mask to expose the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B is sometimes referred to as the second etching process.

[0385] In addition, it is preferable to perform the second etching process using wet etching. By using the wet etching method, damage to the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B can be further reduced as compared with the case of using the dry etching method. Similar to the first etching process, the wet etching can be performed using an acidic chemical solution or an alkaline solution.

[0386] In addition, a heat treatment may also be performed after a part of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B is exposed. By this heat treatment, water contained in the organic compound layer 103 and water adsorbed on the surface of the organic compound layer 103 can be removed. In addition, the shape of the insulating layer 127 sometimes changes due to this heat treatment. Specifically, the insulating layer 127 sometimes expands so as to cover at least one of the end portions of the inorganic insulating layer 125, the end portions of the sacrificial layers 158R, 158G, and 158B, and the top surface of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B.

[0387] Note that Figure 13A An example is shown in which the insulating layer 127 covers a part of the end portion of the sacrificial layer 158 (specifically, the tapered portion formed by the first etching process) and the tapered portion formed by the second etching process is exposed (see Figure 6A ).

[0388] In addition, the insulating layer 127 may also cover the entire end portion of the sacrificial layer 158. For example, the end portion of the insulating layer 127 sometimes droops to cover the end portion of the sacrificial layer 158. In addition, for example, the end portion of the insulating layer 127 sometimes contacts the top surface of at least one of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B.

[0389] Next, as Figure 13B shown, a common electrode 155 is formed on the organic compound layer 103R, the organic compound layer 103G, the organic compound layer 103B, the conductive layer 152C, and the insulating layer 127. The common electrode 155 can be formed by a method such as sputtering or vacuum evaporation. Alternatively, the common electrode 155 can also be formed by laminating a film formed by evaporation and a film formed by sputtering.

[0390] Next, as Figure 13C shown, a protective layer 131 is formed on the common electrode 155. The protective layer 131 can be formed by a method such as vacuum evaporation, sputtering, CVD, or ALD.

[0391] Next, the light-emitting device 1000 can be manufactured by bonding the substrate 120 onto the protective layer 131 using the resin layer 122. As described above, in the method for manufacturing a light-emitting device according to one embodiment of the present invention, the insulating layer 156 is provided so as to include a region overlapping with the side surface of the conductive layer 151, and the conductive layer 152 is formed so as to cover the conductive layer 151 and the insulating layer 156. Thereby, the yield of the light-emitting device can be improved, and the occurrence of defects can be suppressed.

[0392] As described above, in the method for manufacturing a light-emitting device according to one embodiment of the present invention, the island-shaped organic compound layer 103R, the island-shaped organic compound layer 103G, and the organic compound layer 103B are not formed using a high-precision metal mask but are formed by depositing a film on one surface and then processing it. Therefore, the island-shaped layers can be formed with a uniform thickness. In addition, a high-definition light-emitting device or a light-emitting device with a high aperture ratio can be realized. Further, even when the definition or aperture ratio is high and the distance between sub-pixels is extremely short, it is possible to suppress contact between the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B in adjacent sub-pixels. Therefore, it is possible to suppress the occurrence of leakage current between sub-pixels. Thereby, crosstalk can be prevented to realize a light-emitting device with an extremely high contrast. In addition, even for a light-emitting device including a tandem-type light-emitting device manufactured by photolithography, a light-emitting device with good characteristics can be provided.

[0393] This embodiment can be appropriately combined with other embodiments or examples. In addition, in this specification, when a plurality of structural examples are shown in one embodiment, the structural examples can be appropriately combined.

[0394] (Embodiment 3) In this embodiment, with reference to Figures 14A to 15I a light-emitting device according to one embodiment of the present invention will be described.

[0395] [Layout of pixels] In this embodiment, a pixel layout different from Figure 5A will be mainly described. There is no particular limitation on the arrangement of sub-pixels, and various arrangement methods can be adopted. As the arrangement of sub-pixels, for example, stripe arrangement, S-stripe arrangement, matrix arrangement, Delta arrangement, Bayer arrangement, and Pentile arrangement can be cited.

[0396] In this embodiment, the top surface shape of the sub-pixels shown in the drawings corresponds to the top surface shape of the light-emitting region.

[0397] In addition, as the top surface shape of the sub-pixels, for example, polygons such as triangles, quadrilaterals (including rectangles and squares), pentagons, etc., polygon shapes with rounded corners, ellipses, or circles can be cited.

[0398] In addition, the circuit layout constituting the sub-pixels is not limited to the range of the sub-pixels shown in the drawings, and can also be arranged outside thereof.

[0399] Figure 14A The pixel 178 shown adopts an S stripe arrangement. Figure 14A The pixel 178 shown is composed of three sub-pixels: a sub-pixel 110R, a sub-pixel 110G, and a sub-pixel 110B.

[0400] Figure 14B The pixel 178 shown includes a sub-pixel 110R having a top surface shape of an approximate trapezoid with rounded corners, a sub-pixel 110G having a top surface shape of an approximate triangle with rounded corners, and a sub-pixel 110B having a top surface shape of an approximate quadrilateral or approximate hexagon with rounded corners. In addition, the light-emitting area of the sub-pixel 110R is larger than that of the sub-pixel 110G. Thus, the shapes and sizes of the respective sub-pixels can be determined independently. For example, the size of a sub-pixel including a highly reliable light-emitting device can be smaller.

[0401] Figure 14C The pixels 124a and 124b shown adopt a Pentile arrangement. Figure 14C In the example shown, pixels 124a including sub-pixels 110R and 110G and pixels 124b including sub-pixels 110G and 110B are alternately arranged.

[0402] Figures 14D to 14F The pixels 124a and 124b shown adopt a Delta arrangement. The pixel 124a includes two sub-pixels (sub-pixels 110R and 110G) in the upper row (the first row) and one sub-pixel (sub-pixel 110B) in the lower row (the second row). The pixel 124b includes one sub-pixel (sub-pixel 110B) in the upper row (the first row) and two sub-pixels (sub-pixels 110R and 110G) in the lower row (the second row).

[0403] Figure 14D An example is shown where each sub-pixel has a top surface shape of an approximate quadrilateral with rounded corners. Figure 14E An example is shown where each sub-pixel has a circular top surface shape. Figure 14F An example is shown where each sub-pixel has a top surface shape of an approximate hexagon with rounded corners.

[0404] In Figure 14FAmong them, each sub-pixel is arranged inside a hexagonal region arranged in the tightest manner. Each sub-pixel is arranged in such a way that when focusing on one sub-pixel, it is surrounded by six sub-pixels. In addition, the sub-pixels emitting light of the same color are arranged so as not to be adjacent to each other. For example, each sub-pixel is arranged in such a way that when focusing on sub-pixel 110R, three sub-pixels 110G and three sub-pixels 110B that are alternately arranged surround sub-pixel 110R.

[0405] Figure 14G An example in which the sub-pixels of each color are arranged in a zigzag shape is shown. Specifically, in a top view, the positions of the upper sides of two sub-pixels arranged in the row direction (for example, sub-pixel 110R and sub-pixel 110G or sub-pixel 110G and sub-pixel 110B) are offset.

[0406] In Figures 14A to 14G In each of the pixels shown, for example, it is preferable to set sub-pixel 110R as sub-pixel R that emits red light, sub-pixel 110G as sub-pixel G that emits green light, and sub-pixel 110B as sub-pixel B that emits blue light. Note that the structure of the sub-pixels is not limited to this, and the color presented by the sub-pixels and their arrangement order can be appropriately determined. For example, sub-pixel 110G can be set as sub-pixel R that emits red light, and sub-pixel 110R can be set as sub-pixel G that emits green light.

[0407] In photolithography, the finer the pattern to be processed, the more the influence of light diffraction cannot be ignored. Therefore, when transferring the pattern of the photomask through exposure, its fidelity deteriorates, and it is difficult to process the resist mask into the desired shape. Therefore, even if the pattern of the photomask is rectangular, it is easy to form a pattern with rounded corners. Therefore, the top surface shape of the sub-pixel sometimes has a rounded polygonal shape, an elliptical shape, or a circular shape, etc.

[0408] Moreover, in the manufacturing method of a light-emitting device according to one embodiment of the present invention, the organic compound layer is processed into an island shape using a resist mask. The resist film formed on the organic compound layer needs to be cured at a temperature lower than the heat-resistant temperature of the organic compound layer. Therefore, depending on the heat-resistant temperature of the material of the organic compound layer and the curing temperature of the resist material, the curing of the resist film may sometimes be insufficient. The resist film with insufficient curing sometimes has a shape that deviates from the desired shape when being processed. As a result, the top surface shape of the organic compound layer sometimes has a rounded polygonal shape, an elliptical shape, or a circular shape, etc. For example, when a resist mask with a square top surface shape is to be formed, sometimes a resist mask with a circular top surface shape is formed and the top surface shape of the organic compound layer is circular.

[0409] In order to make the top surface shape of the organic compound layer into a desired shape, a technique of pre-correcting a mask pattern in such a way that the design pattern coincides with the transfer pattern (OPC (Optical Proximity Correction) technique) can also be used. Specifically, in the OPC technique, for example, correction patterns are added to the graphic corners on the mask pattern.

[0410] As Figures 15A to 15I shown, a pixel may include four sub-pixels.

[0411] Figures 15A to 15C The pixel 178 shown in the figure adopts a stripe arrangement.

[0412] Figure 15A An example is shown in which each sub-pixel has a rectangular top surface shape. Figure 15B An example is shown in which each sub-pixel has a top surface shape connecting two semi-circles and a rectangle. Figure 15C An example is shown in which each sub-pixel has an elliptical top surface shape.

[0413] Figures 15D to 15F The pixel 178 shown in the figure adopts a matrix arrangement.

[0414] Figure 15D An example is shown in which each sub-pixel has a square top surface shape. Figure 15E An example is shown in which each sub-pixel has a top surface shape of an approximate square with rounded corners. Figure 15F An example is shown in which each sub-pixel has a circular top surface shape.

[0415] Figure 15G And Figure 15H An example is shown in which one pixel 178 is composed of two rows and three columns.

[0416] Figure 15G The pixel 178 shown in the figure includes three sub-pixels (sub-pixel 110R, sub-pixel 110G, sub-pixel 110B) in the upper row (the first row) and one sub-pixel (sub-pixel 110W) in the lower row (the second row). In other words, the pixel 178 includes the sub-pixel 110R in the left column (the first column), the sub-pixel 110G in the central column (the second column), the sub-pixel 110B in the right column (the third column), and the sub-pixel 110W straddles these three columns.

[0417] Figure 15HThe pixel 178 shown includes three sub-pixels (sub-pixel 110R, sub-pixel 110G, sub-pixel 110B) in the upper row (the first row) and three sub-pixels 110W in the lower row (the second row). In other words, the pixel 178 includes sub-pixel 110R and sub-pixel 110W in the left column (the first column), includes sub-pixel 110G and sub-pixel 110W in the central column (the second column), and includes sub-pixel 110B and sub-pixel 110W in the right column (the third column). As Figure 15H shown, by making the configurations of the sub-pixels in the upper row and the lower row consistent, for example, dust that may be generated in the manufacturing process can be efficiently removed. Thereby, a light-emitting device with high display quality can be provided.

[0418] In Figure 15G and Figure 15H the pixel 178 shown, the layouts of sub-pixel 110R, sub-pixel 110G, and sub-pixel 110B are in a stripe arrangement, so the display quality can be improved.

[0419] Figure 15I An example of a pixel 178 composed of three rows and two columns is shown.

[0420] Figure 15I The pixel 178 shown includes sub-pixel 110R in the upper row (the first row), includes sub-pixel 110G in the central row (the second row), includes sub-pixel 110B across the first row to the second row, and includes one sub-pixel (sub-pixel 110W) in the lower row (the third row). In other words, the pixel 178 includes sub-pixel 110R and sub-pixel 110G in the left column (the first column), includes sub-pixel 110B in the right column (the second column), and includes sub-pixel 110W across these two columns.

[0421] In Figure 15I the pixel 178 shown, the layouts of sub-pixel 110R, sub-pixel 110G, and sub-pixel 110B are in a so-called S stripe arrangement, so the display quality can be improved.

[0422] Figures 15A to 15I The pixel 178 shown is composed of four sub-pixels of sub-pixel 110R, sub-pixel 110G, sub-pixel 110B, and sub-pixel 110W. For example, sub-pixel 110R can be set as a sub-pixel that emits red light, sub-pixel 110G can be set as a sub-pixel that emits green light, sub-pixel 110B can be set as a sub-pixel that emits blue light, and sub-pixel 110W can be set as a sub-pixel that emits white light. In addition, at least one of sub-pixel 110R, sub-pixel 110G, sub-pixel 110B, and sub-pixel 110W can be set as a sub-pixel that emits cyan light, magenta light, yellow light, or near-infrared light.

[0423] As described above, in the light-emitting device according to one embodiment of the present invention, various layouts can be adopted for pixels each including a sub-pixel including a light-emitting device.

[0424] This embodiment can be appropriately combined with other embodiments or examples. Further, in this specification, when a plurality of structural examples are shown in one embodiment, these structural examples can be appropriately combined.

[0425] (Embodiment 4) In this embodiment, a light-emitting device according to one embodiment of the present invention will be described.

[0426] The light-emitting device of this embodiment can be a high-definition light-emitting device. Therefore, for example, the light-emitting device of this embodiment can be used as a display unit of information terminal devices (wearable devices) such as watch-type and bracelet-type devices, and as a display unit of wearable devices that can be worn on the head such as VR devices such as head-mounted displays (HMDs) and glasses-type AR devices.

[0427] Further, the light-emitting device of this embodiment can be a high-resolution light-emitting device or a large-sized light-emitting device. Therefore, for example, the light-emitting device of this embodiment can be used as a display unit of the following devices: electronic devices having a relatively large screen such as television devices, desktop or notebook personal computers, monitors for computers, etc., digital signage, and large-sized game machines such as pachinko machines; digital cameras; digital video cameras; digital photo frames; mobile phones; portable game machines; portable information terminals; and sound reproduction devices.

[0428] [Display module] Figure 16A A perspective view of a display module 280 is shown. The display module 280 includes a light-emitting device 100A and an FPC 290. Note that the light-emitting device included in the display module 280 is not limited to the light-emitting device 100A, and can be any one of the light-emitting devices 100B to 100D described later.

[0429] The display module 280 includes a substrate 291 and a substrate 292. The display module 280 includes a display unit 281. The display unit 281 is an image display area in the display module 280, and light from each pixel provided in a pixel unit 284 described below can be seen.

[0430] Figure 16BIt is a perspective view of the structure on one side of the substrate 291. A circuit section 282 is stacked on the substrate 291, a pixel circuit section 283 is on the circuit section 282, and a pixel section 284 is on the pixel circuit section 283. In addition, a terminal section 285 for connecting to the FPC 290 is provided on the part of the substrate 291 that does not overlap with the pixel section 284. The terminal section 285 and the circuit section 282 are electrically connected through a wiring section 286 composed of a plurality of wirings.

[0431] The pixel section 284 includes a plurality of pixels 284a arranged periodically. Figure 16B The right side shows an enlarged view of one pixel 284a. The pixel 284a can adopt various structures described in the above embodiments. Figure 16B It shows a case where the pixel 284a has the same structure as the Figure 5A pixel 178 shown.

[0432] The pixel circuit section 283 includes a plurality of pixel circuits 283a arranged periodically.

[0433] One pixel circuit 283a controls the driving of a plurality of elements included in one pixel 284a. Three circuits for controlling the light emission of one light-emitting device can be provided in one pixel circuit 283a. For example, the pixel circuit 283a can adopt a structure having at least one selection transistor, one current control transistor (driving transistor), and a capacitor for one light-emitting device. At this time, the gate signal is input to the gate of the selection transistor, and the video signal is input to the source or drain. Thus, an active matrix light-emitting device is realized.

[0434] The circuit section 282 includes a circuit for driving each pixel circuit 283a of the pixel circuit section 283. For example, it preferably includes one or both of a gate line driving circuit and a source line driving circuit. In addition, it can also have at least one of an arithmetic circuit, a storage circuit, and a power supply circuit, etc.

[0435] The FPC 290 serves as a wiring for supplying a video signal, a power supply potential, etc. from the outside to the circuit section 282. In addition, an IC can also be mounted on the FPC 290.

[0436] The display module 280 may adopt a structure in which one or both of the pixel circuit portion 283 and the circuit portion 282 are stacked on the lower side of the pixel portion 284, so that the display portion 281 can have an extremely high aperture ratio (effective display area ratio). For example, the aperture ratio of the display portion 281 may be 40% or more and less than 100%, preferably 50% or more and 95% or less, more preferably 60% or more and 95% or less. In addition, the pixels 284a can be arranged with extremely high density, whereby the display portion 281 can have extremely high definition. For example, the pixels 284a of the display portion 281 are preferably arranged with a definition of 2000 ppi or more, more preferably 3000 ppi or more, further preferably 5000 ppi or more, still more preferably 6000 ppi or more and 20000 ppi or less or 30000 ppi or less.

[0437] Such a display module 280 has extremely high definition, so it can be applied to VR devices such as HMDs or glasses-type AR devices. For example, because the display module 280 has a display portion 281 with extremely high definition, in the structure of viewing the display portion of the display module 280 through a lens, even if the display portion is magnified by the lens, the user cannot see the pixels, whereby a display with a high sense of immersion can be realized. In addition, the display module 280 can also be applied to electronic devices with a relatively small display portion. For example, it can be applied to the display portion of wearable electronic devices such as watch-type devices.

[0438] [Light-emitting device 100A] Figure 17A The illustrated light-emitting device 100A includes a substrate 301, a light-emitting device 130R, a light-emitting device 130G, a light-emitting device 130B, a capacitor 240, and a transistor 310.

[0439] The substrate 301 corresponds to Figure 16A and Figure 16B the substrate 291 in. The transistor 310 is a transistor having a channel formation region in the substrate 301. As the substrate 301, for example, a semiconductor substrate such as a single-crystalline silicon substrate can be used. The transistor 310 includes a part of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 is used as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and is used as a gate insulating layer. The low-resistance region 312 is a region in the substrate 301 doped with impurities and is used as a source or a drain. The insulating layer 314 covers the side surface of the conductive layer 311.

[0440] In addition, an element isolation layer 315 is provided between two adjacent transistors 310 in a manner of being embedded in the substrate 301.

[0441] In addition, an insulating layer 261 is provided so as to cover the transistor 310, and a capacitor 240 is provided on the insulating layer 261.

[0442] The capacitor 240 includes a conductive layer 241, a conductive layer 245, and an insulating layer 243 therebetween. The conductive layer 241 serves as one electrode of the capacitor 240, the conductive layer 245 serves as the other electrode of the capacitor 240, and the insulating layer 243 serves as the dielectric of the capacitor 240.

[0443] The conductive layer 241 is provided on the insulating layer 261 and embedded in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source and drain of the transistor 310 through a plug 271 embedded in the insulating layer 261. The insulating layer 243 is provided so as to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping the conductive layer 241 with the insulating layer 243 therebetween.

[0444] An insulating layer 255 is provided so as to cover the capacitor 240, an insulating layer 174 is provided on the insulating layer 255, and an insulating layer 175 is provided on the insulating layer 174. A light-emitting device 130R, a light-emitting device 130G, and a light-emitting device 130B are provided on the insulating layer 175. Figure 17A The light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B are shown to have Figure 13C an example of a stacked structure as shown. An insulator is provided in a region between adjacent light-emitting devices. For example, in Figure 17A this region, an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 are provided.

[0445] An insulating layer 156R is provided so as to have a region overlapping the side surface of the conductive layer 151R included in the light-emitting device 130R, an insulating layer 156G is provided so as to have a region overlapping the side surface of the conductive layer 151G included in the light-emitting device 130G, and an insulating layer 156B is provided so as to have a region overlapping the side surface of the conductive layer 151B included in the light-emitting device 130B. In addition, a conductive layer 152R is provided so as to cover the conductive layer 151R and the insulating layer 156R, a conductive layer 152G is provided so as to cover the conductive layer 151G and the insulating layer 156G, and a conductive layer 152B is provided so as to cover the conductive layer 151B and the insulating layer 156B. Furthermore, a sacrificial layer 158R is located on the organic compound layer 103R included in the light-emitting device 130R, a sacrificial layer 158G is located on the organic compound layer 103G included in the light-emitting device 130G, and a sacrificial layer 158B is located on the organic compound layer 103B included in the light-emitting device 130B.

[0446] The conductive layer 151R, the conductive layer 151G, and the conductive layer 151B are electrically connected to one of the source and drain of the transistor 310 through the plug 256 embedded in the insulating layers 243, 255, 174, and 175, the conductive layer 241 embedded in the insulating layer 254, and the plug 271 embedded in the insulating layer 261. The height of the top surface of the insulating layer 175 is the same as or substantially the same as the height of the top surface of the plug 256. Various conductive materials can be used for the plug.

[0447] In addition, a protective layer 131 is provided on the light-emitting devices 130R, 130G, and 130B. The substrate 120 is bonded to the protective layer 131 by a resin layer 122. Details of the components from the light-emitting devices 130 to the substrate 120 can be referred to in Embodiment 2. The substrate 120 corresponds to Figure 16A the substrate 292.

[0448] Figure 17B Illustrate Figure 17A a modified example of the light-emitting device 100A shown. Figure 17B The shown light-emitting device includes a coloring layer 132R, a coloring layer 132G, and a coloring layer 132B, and the light-emitting device 130 has a region overlapping one of the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B. In Figure 17B the shown light-emitting device, the light-emitting device 130 can emit white light, for example. In addition, for example, the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B can transmit red light, green light, and blue light, respectively.

[0449] [Light-emitting device 100B] Figure 18 A perspective view of the light-emitting device 100B is shown, Figure 19A and a cross-sectional view of the light-emitting device 100B is shown.

[0450] The light-emitting device 100B has a structure in which the substrate 352 is bonded to the substrate 351. In Figure 18 , the substrate 352 is indicated by a dashed line.

[0451] The light-emitting device 100B includes a pixel portion 177, a connection portion 140, a circuit 356, a wiring 355, and the like. Figure 18 An example in which the light-emitting device 100B is mounted with an IC 354 and an FPC 353 is shown. Therefore, the structure shown in Figure 18 can also be referred to as a display module including the light-emitting device 100B, an IC (integrated circuit), and an FPC. Here, the substrate of the light-emitting device on which a connector such as an FPC is mounted or the substrate on which an IC is mounted is called a display module.

[0452] The connection part 140 is provided outside the pixel part 177. The connection part 140 may be provided along one or more sides of the pixel part 177. The number of the connection parts 140 may also be one or more. Figure 18 An example in which the connection part 140 is provided so as to surround the four sides of the display part is shown. In the connection part 140, the common electrode 155 of the light-emitting device is electrically connected to the conductive layer, and a potential can be supplied to the common electrode 155.

[0453] As the circuit 356, for example, a scan line driving circuit can be used.

[0454] The wiring 355 has a function of supplying signals and power to the pixel part 177 and the circuit 356. The signals and power are input to the wiring 355 from the outside via the FPC 353 or input to the wiring 355 from the IC 354.

[0455] Figure 18 An example in which the IC 354 is provided on the substrate 351 by a COG method or a COF (Chip on Film) method or the like is shown. As the IC 354, for example, an IC including a scan line driving circuit or a signal line driving circuit or the like can be used. Note that the light-emitting device 100B and the display module do not necessarily have to be provided with an IC. In addition, for example, the IC can be mounted on the FPC by a COF method.

[0456] Figure 19A An example of a cross section of a part of the region including the FPC 353, a part of the circuit 356, a part of the pixel part 177, a part of the connection part 140, and a part of the region including the end portion of the light-emitting device 100B is shown.

[0457] Figure 19A The shown light-emitting device 100B includes a transistor 201, a transistor 205, a light-emitting device 130R that emits red light, a light-emitting device 130G that emits green light, and a light-emitting device 130B that emits blue light, etc. between the substrate 351 and the substrate 352.

[0458] Except for the difference in the structure of the pixel electrode, the light-emitting devices 130R, 130G, and 130B all have Figure 13C The shown stacked structure. Details of the light-emitting device can be referred to in Embodiment 1 and Embodiment 2.

[0459] The light-emitting device 130R includes a conductive layer 224R, a conductive layer 151R on the conductive layer 224R, and a conductive layer 152R on the conductive layer 151R. The light-emitting device 130G includes a conductive layer 224G, a conductive layer 151G on the conductive layer 224G, and a conductive layer 152G on the conductive layer 151G. The light-emitting device 130B includes a conductive layer 224B, a conductive layer 151B on the conductive layer 224B, and a conductive layer 152B on the conductive layer 151B. Herein, the conductive layer 224R, the conductive layer 151R, and the conductive layer 152R may be collectively referred to as the pixel electrode of the light-emitting device 130R, or the conductive layer 151R and the conductive layer 152R excluding the conductive layer 224R may be referred to as the pixel electrode of the light-emitting device 130R. Similarly, the conductive layer 224G, the conductive layer 151G, and the conductive layer 152G may be collectively referred to as the pixel electrode of the light-emitting device 130G, or the conductive layer 151G and the conductive layer 152G excluding the conductive layer 224G may be referred to as the pixel electrode of the light-emitting device 130G. In addition, the conductive layer 224B, the conductive layer 151B, and the conductive layer 152B may be collectively referred to as the pixel electrode of the light-emitting device 130B, or the conductive layer 151B and the conductive layer 152B excluding the conductive layer 224B may be referred to as the pixel electrode of the light-emitting device 130B.

[0460] The conductive layer 224R is connected to the conductive layer 222b included in the transistor 205 through an opening provided in the insulating layer 214. The end of the conductive layer 151R is located outside the end of the conductive layer 224R. An insulating layer 156R is provided in such a manner as to have a region in contact with the side surface of the conductive layer 151R, and a conductive layer 152R is provided so as to cover the conductive layer 151R and the insulating layer 156R.

[0461] The conductive layer 224G, the conductive layer 151G, the conductive layer 152G, the insulating layer 156G in the light-emitting device 130G, and the conductive layer 224B, the conductive layer 151B, the conductive layer 152B, the insulating layer 156B in the light-emitting device 130B are the same as those in the light-emitting device 130R, so detailed descriptions thereof are omitted.

[0462] Recesses are formed in the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B so as to cover the openings provided in the insulating layer 214. The layer 128 is embedded in the recesses.

[0463] Layer 128 has the function of planarizing the concave portions of conductive layer 224R, conductive layer 224G, and conductive layer 224B. Conductive layers 151R, 151G, and 151B that are electrically connected to conductive layer 224R, conductive layer 224G, and conductive layer 224B respectively are provided on conductive layer 224R and layer 128, conductive layer 224G and layer 128, and conductive layer 224B and layer 128. Therefore, the regions overlapping with the concave portions of conductive layer 224R, conductive layer 224G, and conductive layer 224B can also be used as light-emitting regions, and the aperture ratio of the pixel can be increased.

[0464] Layer 128 can also be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be appropriately used for layer 128. In particular, layer 128 is preferably formed of an insulating material, and particularly preferably formed of an organic insulating material. For example, the organic insulating material that can be used for insulating layer 127 described above can be used for layer 128.

[0465] A protective layer 131 is provided on light-emitting devices 130R, 130G, and 130B. The protective layer 131 and the substrate 352 are bonded by an adhesive layer 142. A light-shielding layer 157 is provided on the substrate 352. The light-emitting device 130 can be sealed using a solid-sealed structure or a hollow-sealed structure, etc. In Figure 19A this case, the space between the substrate 352 and the substrate 351 is filled with the adhesive layer 142, that is, a solid-sealed structure is adopted. Alternatively, this space can also be filled with an inert gas (such as nitrogen or argon) to adopt a hollow-sealed structure. At this time, the adhesive layer 142 can also be provided in a manner that does not overlap with the light-emitting device. In addition, this space can also be filled with a resin different from the adhesive layer 142 provided in a frame shape.

[0466] Figure 19A An example is shown in which the connection portion 140 includes a conductive layer 224C obtained by processing a conductive film the same as conductive layer 224R, conductive layer 224G, and conductive layer 224B, a conductive layer 151C obtained by processing a conductive film the same as conductive layer 151R, conductive layer 151G, and conductive layer 151B, and a conductive layer 152C obtained by processing a conductive film the same as conductive layer 152R, conductive layer 152G, and conductive layer 152B. In addition, Figure 19A An example is shown in which the insulating layer 156C is provided in a manner that has a region overlapping with the side surface of the conductive layer 151C.

[0467] The light-emitting device 100B is a top-emission type display device. The light-emitting device emits light to the substrate 352 side. The substrate 352 is preferably made of a material with high visible light transmittance. The pixel electrode contains a material that reflects visible light, and the counter electrode (common electrode 155) contains a material that transmits visible light.

[0468] Both the transistor 201 and the transistor 205 are formed on the substrate 351. These transistors can be formed using the same material and the same process.

[0469] An insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are sequentially provided on the substrate 351. A part of the insulating layer 211 serves as a gate insulating layer for each transistor. A part of the insulating layer 213 serves as a gate insulating layer for each transistor. The insulating layer 215 is provided so as to cover the transistors. The insulating layer 214 is provided so as to cover each transistor and is used as a planarization layer. In addition, there is no particular limitation on the number of gate insulating layers and the number of insulating layers covering the transistors, and they can be either one or two or more.

[0470] Preferably, a material in which impurities such as water and hydrogen do not easily diffuse is used for at least one of the insulating layers covering the transistors. Thus, the insulating layer can be used as a barrier layer. By adopting such a structure, it is possible to effectively suppress the diffusion of impurities from the outside into the transistors, thereby improving the reliability of the light-emitting device.

[0471] Preferably, an inorganic insulating film is used for the insulating layer 211, the insulating layer 213, and the insulating layer 215. As the inorganic insulating film, for example, a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon oxynitride film, an aluminum oxide film, or an aluminum nitride film can be used. In addition, a hafnium oxide film, a 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 can also be used. In addition, two or more of the above insulating films can be laminated.

[0472] The insulating layer 214 used as a planarization layer preferably uses an organic insulating layer. As materials that can be used for the organic insulating layer, acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimide amide resin, silicone resin, benzocyclobutene resin, phenolic resin, and precursors of the above resins can be cited. In addition, the insulating layer 214 can also have a laminated structure of an organic insulating layer and an inorganic insulating layer. The outermost surface layer of the insulating layer 214 is preferably used as an etching protection layer. Thus, when processing the conductive layer 224R, the conductive layer 151R, or the conductive layer 152R, etc., it is possible to suppress the formation of recesses in the insulating layer 214. Or, recesses can also be provided in the insulating layer 214 when processing the conductive layer 224R, the conductive layer 151R, or the conductive layer 152R, etc.

[0473] The transistor 201 and the transistor 205 include: a conductive layer 221 serving as a gate; an insulating layer 211 serving as a gate insulating layer; conductive layers 222a and 222b serving as a source and a drain; a semiconductor layer 231; an insulating layer 213 serving as a gate insulating layer; and a conductive layer 223 serving as a gate. Here, multiple layers obtained by processing the same conductive film are represented by the same hatching. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

[0474] There is no particular limitation on the transistor structure included in the light-emitting device of the present embodiment. For example, a planar transistor, a vertical transistor, an interleaved transistor, etc. can be adopted. In addition, the transistors can all have a top-gate structure or a bottom-gate structure. Alternatively, gates can be provided above and below the semiconductor layer in which a channel is formed.

[0475] As the transistor 201 and the transistor 205, a structure in which a semiconductor layer forming a channel is clamped by two gates is adopted. In addition, the two gates can be connected, and the transistor can be driven by supplying the same signal to the two gates. Alternatively, by applying a potential for controlling the threshold voltage to one of the two gates and a potential for driving to the other, the threshold voltage of the transistor can also be controlled.

[0476] There is no particular limitation on the crystallinity of the semiconductor material used for the transistor, and an amorphous semiconductor, a semiconductor having crystallinity (microcrystalline semiconductor, polycrystalline semiconductor, single-crystalline semiconductor, or a semiconductor having a crystalline region in a part thereof) can be used. When a semiconductor having crystallinity is used, deterioration of the transistor characteristics can be suppressed, so it is preferable.

[0477] The semiconductor layer of the transistor preferably uses a metal oxide. That is, the light-emitting device of the present embodiment preferably uses a transistor (hereinafter, an OS transistor) including a metal oxide in a channel formation region.

[0478] Examples of the oxide semiconductor having crystallinity include CAAC (c-axis-aligned crystalline)-OS or nc (nanocrystalline)-OS.

[0479] Alternatively, a transistor (Si transistor) using silicon for a channel formation region can also be used. Examples of silicon include single-crystalline silicon, polycrystalline silicon, or amorphous silicon. In particular, a transistor in which a semiconductor layer contains low-temperature polycrystalline silicon (LTPS (Low Temperature Poly Silicon)) (hereinafter, also referred to as an LTPS transistor) can be used. The LTPS transistor has a high field-effect mobility and good frequency characteristics.

[0480] By using Si transistors such as LTPS transistors, circuits that need to be driven at high frequencies (e.g., source driver circuits) and a display section can be formed on the same substrate. Therefore, the external circuits mounted on the light-emitting device can be simplified, and the component cost and mounting cost can be reduced.

[0481] The field-effect mobility of an OS transistor is much higher than that of a transistor using amorphous silicon. In addition, the leakage current between the source and drain in the off state of the OS transistor (hereinafter, also referred to as the off-state current) is extremely low, and the charge stored in a capacitor connected in series with the transistor can be maintained for a long period. In addition, by using an OS transistor, the power consumption of the light-emitting device can be reduced.

[0482] In addition, when increasing the light-emitting luminance of the light-emitting device included in the pixel circuit, it is necessary to increase the amount of current flowing through the light-emitting device. For this purpose, it is necessary to increase the source-drain voltage of the driving transistor included in the pixel circuit. Since the breakdown voltage between the source and drain of the OS transistor is higher than that of the Si transistor, a high voltage can be applied between the source and drain of the OS transistor. Thus, by using an OS transistor as the driving transistor included in the pixel circuit, the amount of current flowing through the light-emitting device can be increased to increase the light-emitting luminance of the light-emitting device.

[0483] In addition, when the transistor operates in the saturation region, compared with the Si transistor, the OS transistor can make the change in the source-drain current with respect to the change in the gate-source voltage finer. Therefore, by using an OS transistor as the driving transistor included in the pixel circuit, the current flowing through the source-drain can be determined in detail according to the change in the gate-source voltage, so that the amount of current flowing through the light-emitting device can be controlled. Thus, the gradation represented by the pixel circuit can be increased.

[0484] In addition, regarding the saturation characteristics of the current flowing when the transistor operates in the saturation region, compared with the Si transistor, the OS transistor can make a stable current (saturation current) flow even when gradually increasing the source-drain voltage. Therefore, by using the OS transistor as the driving transistor, even if, for example, the current-voltage characteristics of the light-emitting device are uneven, a stable current can flow through the light-emitting device. That is, when the OS transistor operates in the saturation region, even if the source-drain voltage is increased, the source-drain current hardly changes, so that the light-emitting luminance of the light-emitting device can be stabilized.

[0485] As described above, by using an OS transistor as the driving transistor included in the pixel circuit, "suppression of black impurity", "increase in light-emitting luminance", "multi-gradation", and "suppression of unevenness of light-emitting devices" can be achieved.

[0486] For example, the semiconductor layer preferably contains indium, M (where M is one or more 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 selected from aluminum, gallium, yttrium, and tin.

[0487] In particular, as the semiconductor layer, an oxide containing indium (In), gallium (Ga), and zinc (Zn) (also denoted as IGZO) is preferably used. Alternatively, an oxide containing indium, tin, and zinc is preferably used. Alternatively, an oxide containing indium, gallium, tin, and zinc is preferably used. Alternatively, an oxide containing indium (In), aluminum (Al), and zinc (Zn) (also referred to as IAZO) is preferably used. Alternatively, an oxide containing indium (In), aluminum (Al), gallium (Ga), and zinc (Zn) (also referred to as IAGZO) is preferably used.

[0488] When an In-M-Zn oxide is used for the semiconductor layer, the atomic ratio of In in the In-M-Zn oxide is preferably equal to or greater than the atomic ratio of M. Examples of the atomic ratios of the metal elements in such an In-M-Zn oxide include compositions such as In:M:Zn = 1:1:1 or in the vicinity thereof, In:M:Zn = 1:1:1.2 or in the vicinity thereof, In:M:Zn = 2:1:3 or in the vicinity thereof, In:M:Zn = 3:1:2 or in the vicinity thereof, In:M:Zn = 4:2:3 or in the vicinity thereof, In:M:Zn = 4:2:4.1 or in the vicinity thereof, In:M:Zn = 5:1:3 or in the vicinity thereof, In:M:Zn = 5:1:6 or in the vicinity thereof, In:M:Zn = 5:1:7 or in the vicinity thereof, In:M:Zn = 5:1:8 or in the vicinity thereof, In:M:Zn = 6:1:6 or in the vicinity thereof, In:M:Zn = 5:2:5 or in the vicinity thereof, etc. In addition, when an In-Zn oxide is used for the semiconductor layer, examples of the atomic ratios of the metal elements in the In-Zn oxide include compositions such as In:Zn = 1:1 or in the vicinity thereof, In:Zn = 2:1 or in the vicinity thereof, and In:Zn = 4:1 or in the vicinity thereof. The vicinity of the composition includes a range of ±30% of the desired atomic ratio.

[0489] For example, when the atomic ratio is described as In:Ga:Zn = 4:2:3 or a composition in the vicinity thereof, it includes the following cases: when In is 4, Ga is 1 or more and 3 or less, and Zn is 2 or more and 4 or less. In addition, when the atomic ratio is described as In:Ga:Zn = 5:1:6 or a composition in the vicinity thereof, it includes the following cases: when In is 5, Ga is more than 0.1 and 2 or less, and Zn is 5 or more and 7 or less. In addition, when the atomic ratio is described as In:Ga:Zn = 1:1:1 or a composition in the vicinity thereof, it includes the following cases: when In is 1, Ga is more than 0.1 and 2 or less, and Zn is more than 0.1 and 2 or less.

[0490] The transistors included in circuit 356 and the transistors included in pixel section 177 may have the same structure or different structures. The multiple transistors included in circuit 356 may have the same structure or two or more different structures. Similarly, the multiple transistors included in pixel section 177 may have the same structure or two or more different structures.

[0491] All of the transistors included in pixel section 177 may be OS transistors, all of the transistors included in pixel section 177 may be Si transistors, and some of the transistors included in pixel section 177 may be OS transistors and the remaining transistors may be Si transistors.

[0492] For example, by using both LTPS transistors and OS transistors in pixel section 177, a light-emitting device with low power consumption and high driving ability can be realized. In addition, the structure combining LTPS transistors and OS transistors is sometimes referred to as LTPO. In addition, for example, it is preferable to use an OS transistor as the transistor for controlling conduction / non-conduction of the control wiring and an LTPS transistor as the transistor for controlling current.

[0493] For example, one of the transistors included in pixel section 177 is used as the transistor for controlling the current flowing through the light-emitting device and may be referred to as 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 for the driving transistor. Thereby, the current flowing through the light-emitting device in the pixel circuit can be increased.

[0494] On the other hand, one of the other transistors included in the pixel section 177 is used as a switch for controlling the selection and non-selection of pixels, and can also be referred to as a selection transistor. The gate of the selection transistor is electrically connected to the gate line, and one of the source and drain is electrically connected to the source line (signal line). The selection transistor preferably uses an OS transistor. Thus, since the gray level of the pixels can be maintained even when the frame frequency is extremely low (for example, 1 fps or less), the power consumption can be reduced by stopping the driver when displaying a still image.

[0495] In this way, the light-emitting device according to one embodiment of the present invention can have a high aperture ratio, high definition, high display quality, and low power consumption.

[0496] Note that the light-emitting device according to one embodiment of the present invention adopts a structure including an OS transistor and a light-emitting device having an MML (Metal MaskLess) structure. By adopting this structure, the leakage current that can flow through the transistor and the leakage current that can flow between adjacent light-emitting devices (sometimes referred to as lateral leakage current, horizontal leakage current, or transverse leakage current) can be made extremely low. In addition, by adopting the above structure, when an image is displayed on the light-emitting device, a viewer can observe any one or more of the sharpness of the image, the sharpness of the image, high color saturation, and high contrast. In addition, by adopting a structure in which the leakage current that can flow through the transistor and the horizontal leakage current between the light-emitting devices are extremely low, it is possible to perform a display with extremely little light leakage (so-called black impurity) that can occur when displaying black.

[0497] In particular, when the above SBS structure is adopted in the light-emitting device of the MML structure, the layer provided between the light-emitting devices (for example, also referred to as an organic layer or a common layer commonly used by the light-emitting devices) is disconnected, whereby the side leakage current can be eliminated or made extremely small.

[0498] Figure 19B and Figure 19C Shows other structural examples of the transistor.

[0499] The transistor 209 and the transistor 210 include: a conductive layer 221 serving as a gate; an insulating layer 211 serving as a gate insulating layer; a semiconductor layer 231 including a channel formation region 231i and a pair of low-resistance regions 231n; a conductive layer 222a connected to one of the pair of low-resistance regions 231n; a conductive layer 222b connected to the other of the pair of low-resistance regions 231n; an insulating layer 225 serving as a gate insulating layer; a conductive layer 223 serving as a gate; and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel formation region 231i. The insulating layer 225 is at least located between the conductive layer 223 and the channel formation region 231i. Furthermore, an insulating layer 218 covering the transistor may also be provided.

[0500] In Figure 19B In the example shown, in transistor 209, the insulating layer 225 covers the top and side surfaces of the semiconductor layer 231. The conductive layers 222a and 222b are connected to the low-resistance region 231n through openings provided in the insulating layer 225 and the insulating layer 215. One of the conductive layers 222a and 222b is used as the source, and the other is used as the drain.

[0501] On the other hand, in Figure 19C In the transistor 210 shown, the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231 and does not overlap with the low-resistance region 231n. For example, by processing the insulating layer 225 using the conductive layer 223 as a mask, the structure shown in Figure 19C can be formed. In Figure 19C , the insulating layer 215 covers the insulating layer 225 and the conductive layer 223, and the conductive layers 222a and 222b are respectively connected to the low-resistance region 231n through openings in the insulating layer 215.

[0502] A connection portion 204 is provided in a region of the substrate 351 that does not overlap with the substrate 352. In the connection portion 204, the wiring 355 is electrically connected to the FPC 353 through the conductive layer 166 and the connection layer 242. The conductive layer 166 shows an example of having a structure: a laminated conductive film obtained by processing a conductive film identical to the conductive layers 224R, 224G, and 224B, a conductive film obtained by processing a conductive film identical to the conductive layers 151R, 151G, and 151B, and a conductive film obtained by processing a conductive film identical to the conductive layers 152R, 152G, and 152B. The conductive layer 166 is exposed on the top surface of the connection portion 204. Therefore, the connection portion 204 can be electrically connected to the FPC 353 through the connection layer 242.

[0503] Preferably, a light-shielding layer 157 is provided on the surface of the substrate 352 on the side of the substrate 351. The light-shielding layer 157 can be provided between adjacent light-emitting devices, in the connection portion 140, the circuit 356, etc. In addition, various optical members can be arranged outside the substrate 352.

[0504] The substrates 351 and 352 can use materials that can be used for the substrate 120.

[0505] As the adhesive layer 142, materials that can be used for the resin layer 122 can be used.

[0506] As the connection layer 242, an anisotropic conductive film (ACF: Anisotropic Conductive Film), an anisotropic conductive paste (ACP: Anisotropic Conductive Paste), etc. can be used.

[0507] [Light-emitting device 100C] Figure 20 The main difference between the light-emitting device 100C shown in A and Figure 19A the light-emitting device 100B shown is that the former is a light-emitting device with a bottom-emission structure.

[0508] The light emitted by the light-emitting device is emitted to the side of the substrate 351. The substrate 351 is preferably made of a material with high visible light transmittance. On the other hand, there is no restriction on the light transmittance of the material for the substrate 352.

[0509] It is preferable to form a light-shielding layer 157 between the substrate 351 and the transistor 201 and between the substrate 351 and the transistor 205. Figure 20 A shows an example where a light-shielding layer 157 is provided on the substrate 351, an insulating layer 153 is provided on the light-shielding layer 157, and transistors 201, 205, etc. are provided on the insulating layer 153.

[0510] The light-emitting device 130R includes a conductive layer 112R, a conductive layer 126R on the conductive layer 112R, and a conductive layer 129R on the conductive layer 126R.

[0511] The light-emitting device 130B includes a conductive layer 112B, a conductive layer 126B on the conductive layer 112B, and a conductive layer 129B on the conductive layer 126B.

[0512] As the conductive layers 112R, 112B, 126R, 126B, 129R, and 129B, materials with high visible light transmittance are each used. As the common electrode 155, a material that reflects visible light is preferably used.

[0513] Note that although Figure 20 the light-emitting device 130G is not shown in A, the light-emitting device 130G is also provided.

[0514] In addition, although Figure 20 A etc. show an example where the top surface of the layer 128 has a flat portion, there is no particular restriction on the shape of the layer 128.

[0515] The common electrode 155 commonly included in a plurality of light-emitting elements is electrically connected to the conductive layer 123 provided in the connection portion 140. The conductive layer 123 shows an example of having a stacked structure, that is, a stack of a conductive layer obtained by processing a conductive film the same as the conductive layers 112R and 112B, a conductive layer obtained by processing a conductive film the same as the conductive layers 126R and 126B, and a conductive layer obtained by processing a conductive film the same as the conductive layers 129R and 129B.

[0516] [Light-emitting device 100D] Figure 21A The light-emitting device 100D shown is Figure 19A a modified example of the light-emitting device 100B shown, and the main difference from the light-emitting device 100B is that it includes a coloring layer 132R, a coloring layer 132G, and a coloring layer 132B.

[0517] In the light-emitting device 100D, the light-emitting device 130 has an area overlapping one of the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B. The coloring layer 132R, the coloring layer 132G, and the coloring layer 132B can be provided on the surface of the substrate 351 on the side of the substrate 352. The ends of the coloring layer 132R, the ends of the coloring layer 132G, and the ends of the coloring layer 132B can overlap the light-shielding layer 157.

[0518] In the light-emitting device 100D, the light-emitting device 130 can emit white light, for example. In addition, for example, the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B can transmit red light, green light, and blue light, respectively. In addition, the light-emitting device 100C can also adopt a structure in which the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B are provided between the protective layer 131 and the adhesive layer 142.

[0519] Although Figure 19A and Figure 21A etc. show examples where the top surface of the layer 128 has a flat portion, there is no particular limitation on the shape of the layer 128. Figures 21B to 21D A modified example of the layer 128 is shown.

[0520] As Figure 21B and Figure 21D shown, the top surface of the layer 128 can have a shape that is concave in the center and its vicinity in cross-section, that is, a shape with a concave curved surface.

[0521] In addition, as Figure 21C shown, the top surface of the layer 128 can have a shape that is convex in the center and its vicinity in cross-section, that is, a shape with a convex curved surface.

[0522] In addition, the top surface of the layer 128 can also have one or both of a convex curved surface and a concave curved surface. In addition, there is no limitation on the number of convex curved surfaces and concave curved surfaces of the top surface of the layer 128, and it can be one or more.

[0523] In addition, the height of the top surface of the layer 128 and the height of the top surface of the conductive layer 224R can be the same or approximately the same, or they can be different. For example, the height of the top surface of the layer 128 can be lower or higher than the height of the top surface of the conductive layer 224R.

[0524] Figure 21BThis can also be an example where layer 128 is accommodated inside the recess formed in conductive layer 224R. On the other hand, as Figure 21D shown, layer 128 can also be formed in such a way that it exists outside the recess formed in conductive layer 224R, that is, formed in such a way that the top surface width of layer 128 is greater than that of the recess.

[0525] This embodiment can be appropriately combined with other embodiments or examples. In addition, in this specification, when multiple structural examples are shown in one embodiment, these structural examples can be appropriately combined.

[0526] (Embodiment 5) In this embodiment, an electronic device of one aspect of the present invention will be described.

[0527] The electronic device of this embodiment includes a light-emitting device of one aspect of the present invention in the display unit. The light-emitting device of one aspect of the present invention has high reliability and is easily capable of high definition and high resolution. Therefore, it can be used in the display units of various electronic devices.

[0528] As electronic devices, for example, in addition to electronic devices with relatively large screens such as television sets, desktop or notebook personal computers, monitors for computers, digital signage, large gaming machines such as pachinko machines, etc., digital cameras, digital video cameras, digital photo frames, mobile phones, portable gaming machines, portable information terminals, sound reproduction devices, etc. can also be cited.

[0529] In particular, since the light-emitting device of one aspect of the present invention can improve clarity, it can be appropriately used in electronic devices including relatively small display units. As such electronic devices, watch-type and bracelet-type information terminal devices (wearable devices), wearable devices that can be worn on the head such as VR devices like head-mounted displays, glasses-type AR devices, and MR devices, etc. can be cited.

[0530] One embodiment of the light-emitting device of the present invention preferably has an extremely high resolution such as HD (number of pixels: 1280×720), FHD (number of pixels: 1920×1080), WQHD (number of pixels: 2560×1440), WQXGA (number of pixels: 2560×1600), 4K (number of pixels: 3840×2160), 8K (number of pixels: 7680×4320), etc. In particular, it is preferably set to a resolution of 4K, 8K or higher. In addition, the pixel density (clarity) of the light-emitting device of one embodiment of the present invention is preferably 100 ppi or more, preferably 300 ppi or more, more preferably 500 ppi or more, more preferably 1000 ppi or more, more preferably 2000 ppi or more, more preferably 3000 ppi or more, more preferably 5000 ppi or more, and further preferably 7000 ppi or more. By using the above light-emitting device having one or both of high resolution and high clarity, the sense of reality and depth can be further enhanced in personal-use electronic devices such as portable or home-use devices. In addition, there is no particular limitation on the screen ratio (aspect ratio) of the light-emitting device of one embodiment of the present invention. For example, the light-emitting device can adapt to various screen ratios such as 1:1 (square), 4:3, 16:9, and 16:10.

[0531] The electronic device of the present embodiment may also include a sensor (the sensor has a function of measuring the following factors: force, displacement, position, speed, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, electric power, radiation, flow rate, humidity, inclination, vibration, odor, or infrared rays).

[0532] The electronic device of the present embodiment can have various functions. For example, it can have the following functions: a function of displaying various information (static images, dynamic images, text images, etc.) on the display unit; a function of a touch panel; a function of displaying a calendar, date, or time, etc.; a function of executing various software (programs); a function of performing wireless communication; a function of reading programs or data stored in a storage medium; etc.

[0533] Use Figures 22A to 22D An example of a wearable device that can be worn on the head will be described. These wearable devices have at least one of the functions of displaying AR content, displaying VR content, displaying SR content, and displaying MR content. When the electronic device has the function of displaying at least one of AR, VR, SR, and MR content, the immersion of the user can be enhanced.

[0534] Figure 22A The shown electronic device 700A and Figure 22BThe illustrated electronic device 700B includes a pair of display panels 751, a pair of frames 721, a communication unit (not shown), a pair of mounting portions 723, a control unit (not shown), an imaging unit (not shown), a pair of optical members 753, a spectacle frame 757, and a pair of nose pads 758.

[0535] The display panel 751 can apply the light-emitting device of one aspect of the present invention. Thereby, a highly reliable electronic device can be realized.

[0536] Both the electronic device 700A and the electronic device 700B can project the image displayed on the display panel 751 onto the display area 756 in the optical member 753. Since the optical member 753 has translucency, the user can see the image displayed in the display area overlapping with the transmitted image seen through the optical member 753. Therefore, both the electronic device 700A and the electronic device 700B are electronic devices capable of performing AR display.

[0537] A camera capable of photographing the front can also be provided as the imaging unit on the electronic device 700A and the electronic device 700B. In addition, by providing an acceleration sensor such as a gyro sensor on the electronic device 700A and the electronic device 700B, the orientation of the user's head can be detected and the image corresponding to the direction can be displayed on the display area 756.

[0538] The communication unit has a wireless communication device, and an image signal can be supplied through the wireless communication device, for example. In addition, instead of or in addition to the wireless communication device, a connector capable of connecting a cable for supplying an image signal and a power potential can be included.

[0539] In addition, the electronic device 700A and the electronic device 700B are provided with a battery (not shown) and can be charged in one or both of a wireless manner and a wired manner.

[0540] The frame 721 can also be provided with a touch sensor module. The touch sensor module has a function of detecting whether the outer surface of the frame 721 is touched. Through the touch sensor module, various processes can be executed by detecting a tap operation or a swipe operation of the user. For example, processes such as temporarily stopping or restarting a moving image can be executed by a tap operation, and processes such as fast forward and rewind can be executed by a swipe operation. In addition, by providing a touch sensor module on each of the two frames 721, the operation range can be expanded.

[0541] As the touch sensor module, various touch sensors can be used. For example, various methods such as a capacitance method, a resistive film method, an infrared method, an electromagnetic induction method, a surface acoustic wave method, and an optical method can be adopted. In particular, it is preferable to apply a capacitance method or an optical method sensor to the touch sensor module.

[0542] When using an optical touch sensor, a photoelectric conversion device (also referred to as a photoelectric conversion element) can be used as the light-receiving element. One or both of an inorganic semiconductor and an organic semiconductor can be used in the active layer of the photoelectric conversion device.

[0543] Figure 22C The electronic device 800A shown and Figure 22D The electronic device 800B shown both include a pair of display units 820, a housing 821, a communication unit 822, a pair of mounting units 823, a control unit 824, a pair of imaging units 825, and a pair of lenses 832.

[0544] The display unit 820 can apply the light-emitting device of one aspect of the present invention. Thereby, a highly reliable electronic device can be realized.

[0545] The display unit 820 is provided at a position inside the housing 821 where it can be seen through the lens 832. In addition, by displaying different images on each of the pair of display units 820, three-dimensional display using parallax can be performed.

[0546] Both the electronic device 800A and the electronic device 800B can be referred to as electronic devices for VR. The user wearing the electronic device 800A or the electronic device 800B can see the image displayed on the display unit 820 through the lens 832.

[0547] The electronic device 800A and the electronic device 800B preferably have a mechanism in which the left and right positions of the lens 832 and the display unit 820 can be adjusted so that the lens 832 and the display unit 820 are located at the most suitable positions according to the position of the user's eyes. In addition, it preferably has a mechanism in which the focus is adjusted by changing the distance between the lens 832 and the display unit 820.

[0548] The user can use the mounting unit 823 to mount the electronic device 800A or the electronic device 800B on the head. For example, in Figure 22C it, the mounting unit 823 has a shape like the temple of glasses (also referred to as temple wires, etc.), but is not limited thereto. As long as the user can mount it, the mounting unit 823 can have a helmet type or a band type shape, for example.

[0549] The imaging unit 825 has a function of acquiring external information. The data acquired by the imaging unit 825 can be output to the display unit 820. An image sensor can be used in the imaging unit 825. In addition, multiple cameras can be provided to be able to correspond to various perspectives such as telephoto and wide angle.

[0550] Note that an example including the imaging unit 825 is shown here, and a distance measurement sensor (hereinafter, also referred to as a detection unit) capable of measuring the dista...

Claims

1. A light-emitting device including an organic compound layer between an anode and a cathode, Among them, wherein the organic compound layer includes at least a light-emitting layer and an electron injection layer, the light-emitting layer contains a light-emitting substance, the electron injection layer is a mixed layer of a first organic compound and a second organic compound, the first organic compound has strong basicity, the second organic compound has electron-transporting properties, and the ordinary light refractive index of the electron injection layer with respect to any wavelength in the range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.

75.

2. A light-emitting device including an organic compound layer between an anode and a cathode, Among them, wherein the organic compound layer includes at least a light-emitting layer and an electron injection layer, the light-emitting layer contains a light-emitting substance, the electron injection layer is a mixed layer of a first organic compound and a second organic compound, the first organic compound has strong basicity, the second organic compound has electron-transporting properties, and the value obtained by adding the ordinary light refractive index of the first organic compound with respect to any wavelength in the range of 455 nm or more and 465 nm or less and dividing the sum by 2 with the ordinary light refractive index of the second organic compound with respect to any wavelength in the range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.

75.

3. A light-emitting device including an organic compound layer between an anode and a cathode, Among them, wherein the organic compound layer includes at least a light-emitting layer and an electron injection layer, the light-emitting layer contains a light-emitting substance, the electron injection layer is a mixed layer of a first organic compound and a second organic compound, the first organic compound has strong basicity, the second organic compound has electron-transporting properties, the ordinary light refractive index of the first organic compound with respect to any wavelength in the range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.80, and the ordinary light refractive index of the second organic compound with respect to any wavelength in the range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.

75.

4. A light-emitting device including an organic compound layer between an anode and a cathode, Among them, wherein the organic compound layer includes at least a light-emitting layer and an electron injection layer, the light-emitting layer contains a light-emitting substance, the electron injection layer is a mixed layer of a first organic compound and a second organic compound, the first organic compound has a guanidine skeleton, the second organic compound has electron-transporting properties, and the ordinary light refractive index of the electron injection layer with respect to any wavelength in the range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.

75.

5. A light-emitting device including an organic compound layer between an anode and a cathode, Among them, wherein the organic compound layer includes at least a light-emitting layer and an electron injection layer, the light-emitting layer contains a light-emitting substance, the electron injection layer is a mixed layer of a first organic compound and a second organic compound, the first organic compound has a guanidine skeleton, the second organic compound has electron-transporting properties, Moreover, the value obtained by adding the ordinary light refractive index of the first organic compound with respect to any wavelength in the range of 455 nm or more and 465 nm or less and dividing the sum by 2 is 1.50 or more and less than 1.

75.

6. A light-emitting device including an organic compound layer between an anode and a cathode, Among them, wherein the organic compound layer includes at least a light-emitting layer and an electron injection layer, the light-emitting layer contains a light-emitting substance, the electron injection layer is a mixed layer of a first organic compound and a second organic compound, the first organic compound has a guanidine skeleton, the second organic compound has electron-transporting properties, the ordinary light refractive index of the first organic compound with respect to any wavelength in the range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.80, and the ordinary light refractive index of the second organic compound with respect to any wavelength in the range of 455 nm or more and 465 nm or less is 1.50 or more and less than 1.

75.

7. The light-emitting device according to any one of claims 1 to 3, wherein the first organic compound has a guanidine skeleton.

8. The light-emitting device according to any one of claims 1 to 6, wherein the first organic compound has a 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine skeleton.

9. The light-emitting device according to any one of claims 1 to 6, wherein the first organic compound exhibits a strong basicity with an acidity coefficient pKa of 8 or more.

10. The light-emitting device according to any one of claims 1 to 6, wherein the first organic compound does not have an electron-transporting skeleton.

11. The light-emitting device according to any one of claims 1 to 6, Among them, the ratio of the total number of carbon atoms forming bonds in sp 3 hybrid orbitals to the total number of carbon atoms in the molecule of the first organic compound is 10% or more and 60% or less.

12. The light-emitting device according to any one of claims 1 to 6, Among them, the ratio of the total number of carbon atoms forming bonds in the intramolecular of the second organic compound with sp 3 hybrid orbitals to the total number of carbon atoms is 10% or more and 60% or less.

13. The light-emitting device according to any one of claims 1 to 6, wherein the integral value of the signal less than 4 ppm in the 1 1H-NMR measurement result of the second organic compound is larger than the integral value of the signal above 4 ppm.

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