Light-emitting device and display device

Abstract

Provided are a light-emitting device and a display device having good characteristics. The light emitting device includes first and second electrodes, an intermediate layer disposed therebetween, first and second light emitting layers disposed between the first electrode and the intermediate layer, first and second light emitting layers disposed between the intermediate layer and the second electrode, first and second electron transport layers disposed between the first light emitting layer and the intermediate layer, and first and second electron transport layers disposed between the second light emitting layer and the intermediate layer. The second electron transport layer is located between the second light-emitting layer and the second electrode, the second electron transport layer has a laminated structure, the intermediate layer has a second organic compound containing a phenanthroline skeleton, and the first light-emitting layer and the second light-emitting layer contain the same light-emitting center substance. And the first light-emitting layer and the second light-emitting layer are separated from the light-emitting layer included in at least one of the plurality of other light-emitting devices adjacent to the light-emitting device.

Description

Technical Field

[0001] One aspect of the present invention relates to an organic compound, an organic semiconductor element, a light-emitting device, a photodiode sensor, a display module, a lighting module, 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 object, 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, semiconductor devices, display devices, liquid crystal display devices, lighting devices, power storage devices, storage devices, imaging devices, driving methods of these devices, or manufacturing methods of these devices can be cited. Background Art

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

[0003] Since the light-emitting device is a self-luminous device, a display device using this light-emitting device for pixels has higher visibility than a liquid crystal display device and does not require a backlight. In addition, a display device 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] In addition, since the light-emitting layer of such a light-emitting device can be formed continuously in a planar shape, surface light emission can be obtained. Since this is a characteristic that is difficult to obtain in point light sources represented by incandescent lamps and LEDs or line light sources represented by fluorescent lamps, the above light-emitting device also has high utility value as a surface light source that can be used for lighting and the like.

[0005] As described above, although display devices and lighting devices using light-emitting devices are applicable to various electronic devices, research and development of light-emitting devices with better characteristics are becoming increasingly active.

[0006] In particular, tandem light-emitting devices have attracted attention due to their high current efficiency, and Patent Document 1 and Patent Document 2 disclose tandem light-emitting devices of a separate coating method.

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-317548 [Patent Document 2] Japanese Patent Application Laid-Open No. 2023-161850 SUMMARY OF THE INVENTION

[0008] An object of one aspect of the present invention is to provide a light-emitting device with good characteristics. In addition, an object of one aspect of the present invention is to provide a light-emitting device with good luminous efficiency. In addition, an object of one aspect of the present invention is to provide a light-emitting device with good reliability. In addition, an object of one aspect of the present invention is to provide a light-emitting device with a low driving voltage. In addition, an object of one aspect of the present invention is to provide a light-emitting device with good reliability and a low driving voltage.

[0009] In addition, an object of one aspect of the present invention is to provide a light-emitting device capable of providing a display device with good characteristics. In addition, an object of one aspect of the present invention is to provide a light-emitting device capable of providing a display device with good luminous efficiency. In addition, an object of one aspect of the present invention is to provide a light-emitting device capable of providing a display device with good reliability. In addition, an object of one aspect of the present invention is to provide a light-emitting device capable of providing a display device with a low driving voltage. In addition, an object of one aspect of the present invention is to provide a light-emitting device capable of providing a display device with a low driving voltage and good reliability.

[0010] In addition, an object of one aspect of the present invention is to provide any one of an organic semiconductor device, a light-emitting device, a light-receiving device, a display device, an electronic device, and a lighting device with low power consumption. In addition, an object of one aspect of the present invention is to provide any one of an electronic device and a lighting device with high reliability. In addition, an object of one aspect of the present invention is to provide any one of a novel organic semiconductor device, a light-emitting device, a light-receiving device, a display device, an electronic device, and a lighting device.

[0011] The present invention only needs to achieve any one of the above objects. Note that the description of these objects does not preclude the existence of other objects. Note that one aspect of the present invention does not need to achieve all of the above objects. In addition, there are clearly other objects in the description of the specification, drawings, claims, etc., and the other objects can be obtained from the description of the specification, drawings, claims, etc.

[0012] One aspect of the present invention is a light-emitting device, which includes a first electrode, a second electrode, an intermediate layer, a first light-emitting layer, a second light-emitting layer, a first electron transport layer, and a second electron transport layer. The intermediate layer is located between the first electrode and the second electrode. The first light-emitting layer is located between the first electrode and the intermediate layer. The second light-emitting layer is located between the intermediate layer and the second electrode. The first electron transport layer is located between the first light-emitting layer and the intermediate layer. The second electron transport layer is located between the second light-emitting layer and the second electrode. The second electron transport layer has at least a stacked structure of a third electron transport layer and a fourth electron transport layer. The fourth electron transport layer is located between the third electron transport layer and the second electrode. The intermediate layer includes a mixed layer of a second organic compound having a phenanthroline skeleton and lithium or a lithium compound. The first light-emitting layer contains a first light-emitting center substance. The second light-emitting layer contains a second light-emitting center substance. The difference between the maximum peak wavelength of the emission spectrum of the first light-emitting center substance and the maximum peak wavelength of the emission spectrum of the second light-emitting center substance is 30 nm or less, and the first light-emitting layer and the second light-emitting layer are different from the light-emitting layers included in at least one of a plurality of other light-emitting devices adjacent to the light-emitting device.

[0013] In addition, another aspect of the present invention is a light-emitting device, which includes a first electrode, a second electrode, an intermediate layer, a first light-emitting layer, a second light-emitting layer, a first electron transport layer, and a second electron transport layer. The intermediate layer is located between the first electrode and the second electrode. The first light-emitting layer is located between the first electrode and the intermediate layer. The second light-emitting layer is located between the intermediate layer and the second electrode. The first electron transport layer is located between the first light-emitting layer and the intermediate layer. The second electron transport layer is located between the second light-emitting layer and the second electrode. The second electron transport layer has at least a stacked structure of a third electron transport layer and a fourth electron transport layer. The fourth electron transport layer is located between the third electron transport layer and the second electrode. The fourth electron transport layer has a first organic compound containing a triazine skeleton. The intermediate layer includes a mixed layer of a second organic compound having a phenanthroline skeleton and lithium or a lithium compound. The first light-emitting layer contains a first light-emitting center substance. The second light-emitting layer contains a second light-emitting center substance. The difference between the maximum peak wavelength of the emission spectrum of the first light-emitting center substance and the maximum peak wavelength of the emission spectrum of the second light-emitting center substance is 30 nm or less, and the first light-emitting layer and the second light-emitting layer are different from the light-emitting layers included in at least one of a plurality of other light-emitting devices adjacent to the light-emitting device.

[0014] In addition, another aspect of the present invention is a light-emitting device, which includes a first electrode, a second electrode, an intermediate layer, a first light-emitting layer, a second light-emitting layer, a first electron transport layer, and a second electron transport layer. The intermediate layer is located between the first electrode and the second electrode. The first light-emitting layer is located between the first electrode and the intermediate layer. The second light-emitting layer is located between the intermediate layer and the second electrode. The first electron transport layer is located between the first light-emitting layer and the intermediate layer. The second electron transport layer is located between the second light-emitting layer and the second electrode. The second electron transport layer has at least a stacked structure of a third electron transport layer and a fourth electron transport layer. The fourth electron transport layer is located between the third electron transport layer and the second electrode. The fourth electron transport layer has a first organic compound containing a triazine skeleton. The first electron transport layer has a third organic compound containing a triazine skeleton. The intermediate layer has a second organic compound containing a phenanthroline skeleton. The first light-emitting layer contains a first light-emitting center substance. The second light-emitting layer contains a second light-emitting center substance. The difference between the maximum peak wavelength of the emission spectrum of the first light-emitting center substance and the maximum peak wavelength of the emission spectrum of the second light-emitting center substance is 30 nm or less. And the first light-emitting layer and the second light-emitting layer are different from the light-emitting layers included in at least one of a plurality of other light-emitting devices adjacent to the light-emitting device.

[0015] In addition, another aspect of the present invention is a light-emitting device having the above structure, wherein the intermediate layer contains lithium or a lithium compound.

[0016] In addition, another aspect of the present invention is a light-emitting device having the above structure, wherein the intermediate layer includes a mixed layer of a second organic compound and lithium or a lithium compound.

[0017] In addition, another aspect of the present invention is a light-emitting device having the above structure, wherein the fourth electron transport layer contains lithium or a lithium compound.

[0018] In addition, another aspect of the present invention is a light-emitting device having the above structure, wherein the first light-emitting center substance is the same as the second light-emitting center substance.

[0019] In addition, another aspect of the present invention is a light-emitting device having the above structure, wherein the intermediate layer includes a first layer containing a second organic compound.

[0020] In addition, another aspect of the present invention is a light-emitting device having the above structure, wherein the intermediate layer further includes a second layer, and the second layer is located between the first layer and the second light-emitting layer.

[0021] In addition, another aspect of the present invention is a light-emitting device having the above structure, wherein the second layer contains a fourth organic compound having hole-transporting properties.

[0022] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the second layer contains a halogen.

[0023] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the second layer contains an organic compound having a halogen group and / or a cyano group.

[0024] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the second layer contains an organic compound having a fluorine and / or a cyano group.

[0025] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the second layer contains an organic compound having a halogen group and / or a cyano group, and the number of the halogen group and / or the cyano group is 4 or more.

[0026] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the second layer contains an organic compound having a fluorine and / or a cyano group, and the number of the fluorine and / or the cyano group is 4 or more.

[0027] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the first electron transport layer has at least a stacked structure of a fifth electron transport layer and a sixth electron transport layer, and the sixth electron transport layer is located between the fifth electron transport layer and the intermediate layer.

[0028] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the sixth electron transport layer has a third organic compound containing a triazine skeleton.

[0029] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the first organic compound is the same as the third organic compound.

[0030] In addition, another aspect of the present invention is a display device including any of the above light-emitting devices.

[0031] In addition, another aspect of the present invention is a display device, which includes a first light-emitting device and a second light-emitting device. The first light-emitting device and the second light-emitting device are adjacent to each other. The first light-emitting device includes a first electrode, a second electrode, a first intermediate layer, a first light-emitting layer, a second light-emitting layer, a first electron transport layer, and a second electron transport layer. The first intermediate layer is located between the first electrode and the second electrode. The first light-emitting layer is located between the first electrode and the first intermediate layer. The second light-emitting layer is located between the first intermediate layer and the second electrode. The first electron transport layer is located between the first light-emitting layer and the first intermediate layer. The second electron transport layer is located between the second light-emitting layer and the second electrode. The second electron transport layer has at least a stacked structure of a third electron transport layer and a fourth electron transport layer. The fourth electron transport layer is located between the third electron transport layer and the second electrode. The second light-emitting device includes a third electrode, a fourth electrode, a second intermediate layer, a third light-emitting layer, a fourth light-emitting layer, a fifth electron transport layer, and a sixth electron transport layer. The second intermediate layer is located between the third electrode and the fourth electrode. The third light-emitting layer is located between the third electrode and the second intermediate layer. The fourth light-emitting layer is located between the second intermediate layer and the fourth electrode. The fifth electron transport layer is located between the third light-emitting layer and the second intermediate layer. The sixth electron transport layer is located between the fourth light-emitting layer and the fourth electrode. The sixth electron transport layer has at least a stacked structure of a seventh electron transport layer and an eighth electron transport layer. The eighth electron transport layer is located between the seventh electron transport layer and the fourth electrode. The fourth electron transport layer and the eighth electron transport layer are made of the same material. The first intermediate layer and the second intermediate layer contain a second organic compound having a phenanthroline skeleton and lithium or a lithium compound. The first light-emitting layer contains a first light-emitting center substance. The second light-emitting layer contains a second light-emitting center substance. The third light-emitting layer contains a third light-emitting center substance. The fourth light-emitting layer contains a fourth light-emitting center substance. The difference between the maximum peak wavelength of the emission spectrum of the first light-emitting center substance and the maximum peak wavelength of the emission spectrum of the second light-emitting center substance is 30 nm or less. The difference between the maximum peak wavelength of the emission spectrum of the third light-emitting center substance and the maximum peak wavelength of the emission spectrum of the fourth light-emitting center substance is 30 nm or less. The first light-emitting layer is different from the third light-emitting layer, and the second light-emitting layer is different from the fourth light-emitting layer.

[0032] In addition, another aspect of the present invention is a display device, which includes a first light-emitting device and a second light-emitting device. The first light-emitting device and the second light-emitting device are adjacent to each other. The first light-emitting device includes a first electrode, a second electrode, a first intermediate layer, a first light-emitting layer, a second light-emitting layer, a first electron transport layer, and a second electron transport layer. The first intermediate layer is located between the first electrode and the second electrode. The first light-emitting layer is located between the first electrode and the first intermediate layer. The second light-emitting layer is located between the first intermediate layer and the second electrode. The first electron transport layer is located between the first light-emitting layer and the first intermediate layer. The second electron transport layer is located between the second light-emitting layer and the second electrode. The second electron transport layer has at least a stacked structure of a third electron transport layer and a fourth electron transport layer. The fourth electron transport layer is located between the third electron transport layer and the second electrode. The second light-emitting device includes a third electrode, a fourth electrode, a second intermediate layer, a third light-emitting layer, a fourth light-emitting layer, a fifth electron transport layer, and a sixth electron transport layer. The second intermediate layer is located between the third electrode and the fourth electrode. The third light-emitting layer is located between the third electrode and the second intermediate layer. The fourth light-emitting layer is located between the second intermediate layer and the fourth electrode. The fifth electron transport layer is located between the third light-emitting layer and the second intermediate layer. The sixth electron transport layer is located between the fourth light-emitting layer and the fourth electrode. The sixth electron transport layer has at least a stacked structure of a seventh electron transport layer and an eighth electron transport layer. The eighth electron transport layer is located between the seventh electron transport layer and the fourth electrode. The second electron transport layer and the sixth electron transport layer are continuous layers. The first intermediate layer and the second intermediate layer contain a second organic compound having a phenanthroline skeleton and lithium or a lithium compound. The first light-emitting layer contains a first light-emitting center substance. The second light-emitting layer contains a second light-emitting center substance. The third light-emitting layer contains a third light-emitting center substance. The fourth light-emitting layer contains a fourth light-emitting center substance. The difference between the maximum peak wavelength of the emission spectrum of the first light-emitting center substance and the maximum peak wavelength of the emission spectrum of the second light-emitting center substance is 30 nm or less. The difference between the maximum peak wavelength of the emission spectrum of the third light-emitting center substance and the maximum peak wavelength of the emission spectrum of the fourth light-emitting center substance is 30 nm or less. The first light-emitting layer is different from the third light-emitting layer, and the second light-emitting layer is different from the fourth light-emitting layer.

[0033] In addition, another aspect of the present invention is an electronic device, which includes: the above-described light-emitting device; a sensor, an operation button, a speaker, or a microphone.

[0034] In addition, another aspect of the present invention is a lighting device, which includes: the above-described light-emitting device; and a housing.

[0035] The above is one aspect of the present invention and is not limited to the above structure.

[0036] According to one aspect of the present invention, a light-emitting device with good characteristics can be provided. In addition, according to one aspect of the present invention, a light-emitting device with good luminous efficiency can be provided. In addition, according to one aspect of the present invention, a light-emitting device with good reliability can be provided. In addition, according to one aspect of the present invention, a light-emitting device with a low driving voltage can be provided. In addition, according to one aspect of the present invention, a light-emitting device with good reliability and a low driving voltage can be provided.

[0037] In addition, according to one aspect of the present invention, a light-emitting device capable of providing a display device with good characteristics can be provided. In addition, according to one aspect of the present invention, a light-emitting device capable of providing a display device with good luminous efficiency can be provided. In addition, according to one aspect of the present invention, a light-emitting device capable of providing a display device with good reliability can be provided. In addition, according to one aspect of the present invention, a light-emitting device capable of providing a display device with a low driving voltage can be provided. In addition, according to one aspect of the present invention, a light-emitting device capable of providing a display device with a low driving voltage and good reliability can be provided.

[0038] In addition, according to one aspect of the present invention, any one of an organic semiconductor device, a light-emitting device, a light-receiving device, a display device, an electronic device, and a lighting device with low power consumption can be provided. In addition, according to one aspect of the present invention, any one of an electronic device and a lighting device with high reliability can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1A and Figure 1B is a schematic diagram of a light-emitting device according to one aspect of the present invention; Figure 2 is a schematic diagram of a light-emitting device according to one aspect of the present invention; Figure 3 is a schematic diagram of a light-emitting device according to one aspect of the present invention; Figure 4 is a schematic diagram of a light-emitting device according to one aspect of the present invention; Figure 5A and Figure 5B is a diagram showing a display device according to one aspect of the present invention; Figure 6A and Figure 6B is a diagram showing a display device according to one aspect of the present invention; Figures 7A to 7E is a cross-sectional view showing an example of a method for manufacturing a display device; Figure 8A and Figure 8B is a cross-sectional view showing an example of a method for manufacturing a display device; Figures 9A to 9Dis a cross-sectional view showing an example of a method for manufacturing a display device; Figures 10A to 10C is a cross-sectional view showing an example of a method for manufacturing a display device; Figures 11A to 11C is a cross-sectional view showing an example of a method for manufacturing a display device; Figures 12A to 12C is a cross-sectional view showing an example of a method for manufacturing a display device; Figure 13A and Figure 13B is a perspective view showing an example of the structure of a display module; Figure 14A and Figure 14B is a cross-sectional view showing an example of the structure of a display device; Figure 15 is a perspective view showing an example of the structure of a display device; Figure 16 is a cross-sectional view showing an example of the structure of a display device; Figure 17 is a cross-sectional view showing an example of the structure of a display device; Figures 18A to 18C is a view showing an example of the structure of a display device; Figure 19 is a cross-sectional view showing an example of the structure of a display device; Figures 20A to 20C is a view showing an example of the structure of a display device; Figures 21A to 21D is a view illustrating an example of a wearable device; Figures 22A to 22F is a view showing an example of an electronic device; Figures 23A to 23G is a view showing an example of an electronic device; Figure 24 is a graph showing the current density-voltage characteristics of the light-emitting device R1 and the comparative light-emitting device R1; Figure 25 is a graph showing the current efficiency-luminance characteristics of the light-emitting device R1 and the comparative light-emitting device R1; Figure 26 is a graph showing the power efficiency-luminance characteristics of the light-emitting device R1 and the comparative light-emitting device R1; Figure 27 is a graph showing the electroluminescence spectra of the light-emitting device R1 and the comparative light-emitting device R1; Figure 28 is a graph showing the current density-voltage characteristics of the light-emitting device G1 and the comparative light-emitting device G1; Figure 29 is a graph showing the current efficiency-luminance characteristics of the light-emitting device G1 and the comparative light-emitting device G1; Figure 30 is a graph showing the power efficiency - luminance characteristics of the light - emitting device G1 and the comparative light - emitting device G1; Figure 31 is a graph showing the electroluminescence spectra of the light - emitting device G1 and the comparative light - emitting device G1; Figure 32 is a graph showing the current density - voltage characteristics of the light - emitting device B1 and the comparative light - emitting device B1; Figure 33 is a graph showing the current efficiency - luminance characteristics of the light - emitting device B1 and the comparative light - emitting device B1; Figure 34 is a graph showing the blue - light efficiency index - luminance characteristics of the light - emitting device B1 and the comparative light - emitting device B1; Figure 35 is a graph showing the power efficiency - luminance characteristics of the light - emitting device B1 and the comparative light - emitting device B1; Figure 36 is a graph showing the electroluminescence spectra of the light - emitting device B1 and the comparative light - emitting device B1. Detailed Embodiments

[0040] Hereinafter, embodiments of the present invention 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 understood by those of ordinary skill in the art that its mode and detailed content can be changed into various forms without departing from the spirit 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.

[0041] Note that in this specification and the like, a device manufactured using a metal mask or an FMM (Fine Metal Mask) may sometimes be referred to as a device having an MM (Metal Mask) structure. In addition, in this specification and the like, a device not manufactured using a metal mask or an FMM may sometimes be referred to as a device having an MML (Metal Mask Less) structure.

[0042] Embodiment 1 A tandem - type light - emitting device has a structure in which a plurality of light - emitting units are stacked with an intermediate layer (charge - generation layer) sandwiched between a pair of electrodes. Each of the plurality of light - emitting units includes a light - emitting layer, and by passing a current therethrough, light emission can be obtained from any of the light - emitting layers. The current efficiency of a tandem - type light - emitting device having such a structure is much higher than that of a non - tandem - type light - emitting device, so it can be used for a display device that requires high - brightness display or a display device that requires high reliability.

[0043] A tandem light-emitting device can easily achieve white light emission due to having multiple light-emitting layers. Therefore, as a full-colorization method for a display device using a tandem light-emitting device, a white filter method is mostly adopted. In addition, a color conversion method in which a light-emitting layer that emits blue light is stacked and a color conversion layer represented by quantum dots is used has also been put into practical use.

[0044] On the other hand, some display devices that adopt a separate coating method as a full-colorization method and use a tandem light-emitting device have also been put into practical use. The light-emitting device of the separate coating method has no or little energy loss in the color filter or the color conversion layer, so it can achieve high luminous efficiency compared with the above two methods.

[0045] In one aspect of the present invention, in a tandem light-emitting device, the electron transport layer included in the light-emitting unit on the cathode side has a stacked structure, and the intermediate layer has a second organic compound containing a phenanthroline skeleton.

[0046] In addition, the light-emitting layer included in the tandem light-emitting device is preferably separated from the light-emitting layer included in at least one of the adjacent other light-emitting devices. In addition, the light-emitting layer included in the tandem light-emitting device is preferably different from the light-emitting layer included in at least one of the adjacent other light-emitting devices. In addition, the light-emitting color presented by the tandem light-emitting device or a pixel including the tandem light-emitting device is preferably different from the light-emitting color presented by at least one of the adjacent other light-emitting devices or pixels. In addition, the light-emitting center substance included in the light-emitting layer of the tandem light-emitting device is preferably different from the light-emitting center substance included in the light-emitting layer of at least one of the adjacent other light-emitting devices.

[0047] The light-emitting device of the present invention having such a structure can be a light-emitting device with high current efficiency, less energy loss, and good characteristics. A display device according to one aspect of the present invention using such a light-emitting device can be a display device with low power consumption, high reliability, and good visibility capable of displaying at high brightness.

[0048] The electron transport layer included in the light-emitting unit on the anode side preferably has a stacked structure, thereby reducing power consumption.

[0049] In addition, the electron transport layer included in the light-emitting unit on the anode side can have a stacked structure or a single-layer structure. When it has a stacked structure, a light-emitting device with high current efficiency, lower power consumption, and good characteristics can be provided. When it has a single-layer structure, the number of deposition processing chambers is small, so it is advantageous from the viewpoint of manufacturing cost.

[0050] As the above-mentioned second organic compound containing a phenanthroline skeleton, any substance with higher electron transportability than hole transportability can be used, but preferably, the electron mobility when the square root of the electric field strength [V / cm] is 600 is 1×10- 7 cm 2 above / Vs, preferably 1×10 -6 cm 2 or more of the organic compound.

[0051] As the second organic compound containing a phenanthroline skeleton, a compound containing a phenanthroline skeleton and an aromatic ring is preferred. As the aromatic ring, a monocyclic aromatic ring, a polycyclic aromatic ring, etc. are preferably used.

[0052] Examples of the monocyclic aromatic ring include a benzene ring, a pyrrole ring, a pyridine ring, a pyrimidine ring, etc. In addition, as the polycyclic aromatic ring, in addition to aromatic hydrocarbon rings such as a naphthalene ring, a phenanthrene ring, a ring, a triphenylene ring, a fluorene ring, etc., heteroaromatic rings such as a phenanthroline ring and a pyrrole ring are preferably included. In particular, by having a plurality of the above polycyclic aromatic rings, heat resistance and electron transport properties can be improved, so it is preferred.

[0053] As the second organic compound containing a phenanthroline skeleton, for example, bathocuproine (abbreviation: Bphen), bathocuproin (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-[3-(2-triphenylene)phenyl]-1,10-phenanthroline (abbreviation: mTpPPhen), 2-phenyl-9-(2-triphenylene)-1,10-phenanthroline (abbreviation: Ph-TpPhen), 2-[4-(9-phenanthryl)-1-naphthyl]-1,10-phenanthroline (abbreviation: PnNPhen), 2-[4-(2-triphenylene)phenyl]-1,10-phenanthroline (abbreviation: pTpPPhen) and other organic compounds containing a heteroaromatic ring having a phenanthroline skeleton can be used. In particular, PnNPhen (200), mPPhen2P (201), etc. represented by the following structural formulas (200) to (201) are preferably used.

[0054] [Chemical formula 1]

[0055] In the light-emitting device according to one embodiment of the present invention, the intermediate layer can have any structure as long as it contains a second organic compound having a phenanthroline skeleton and can inject electrons into the light-emitting unit on the anode side in contact with the intermediate layer and inject holes into the light-emitting unit on the cathode side by applying a voltage between the first electrode and the second electrode. Note that the intermediate layer preferably has a laminated structure of a first layer containing a second organic compound and a second layer located closer to the cathode side than the first layer.

[0056] The first layer preferably contains a metal or a metal compound in addition to the second organic compound. The metal in the metal or metal compound is preferably an element such as: alkali metals (Group 1 elements) such as Li; alkaline earth metals (Group 2 elements) such as Mg and Ca; Group 3 elements including lanthanide elements such as Y, Eu, and Yb; Group 11 elements such as Cu, Ag, and Au; Group 12 elements such as Zn; and earth metals (Group 13 elements) such as Al and In.

[0057] Note that the first layer may have a laminated structure including a layer containing an organic compound and a layer containing a metal or a metal compound located closer to the cathode side than the layer containing the organic compound, or may be a mixed layer of an organic compound and a metal or a metal compound. When the first layer is a mixed layer, the deposition processing chamber is less, the manufacturing cost is reduced, and it helps to improve the stability of the light-emitting device, so it is preferred.

[0058] In the case where an organic compound and a metal or a metal compound are mixed, when analyzing the first layer in the thickness direction, the distribution of the organic compound and the distribution of the metal or the metal compound show substantially the same trend. That is, when the distribution of the organic compound is fixed, the distribution of the metal or the metal compound is also substantially fixed. In the laminated structure of a layer containing an organic compound and a layer containing a metal or a metal compound, sometimes the metal or the metal compound diffuses from the layer containing the metal or the metal compound and is detected in a region outside the layer, but since it shows a distribution different from that of the organic compound, the analysis results of diffusion and mixing can be distinguished.

[0059] In addition, when analyzing the first layer in the thickness direction, when the thickness of the region where the metal or the metal compound is detected is 10 nm or more, preferably 15 nm or more, and more preferably 20 nm or more, the first layer can be regarded as a mixed layer including a mixture of an organic compound and a metal or a metal compound.

[0060] The metal in the above-mentioned metal or metal compound is preferably a substance that exhibits donor properties to the second organic compound. As a substance that exhibits donor properties to the second organic compound, for example, metals of Group 1 and Group 2 can be cited, and lithium or a lithium compound is particularly preferably used. Specifically, Li, lithium fluoride (LiF), lithium oxide (Li2O), and 8-hydroxyquinoline-lithium (abbreviation: Liq) etc. are preferably used. When the first layer contains the second organic compound and a substance that exhibits donor properties to the second organic compound, electrons are generated by charge separation, and when a voltage is applied between the first electrode and the second electrode, the electrons are injected into the light-emitting unit on the anode side through the second organic compound. Thus, the light-emitting device according to one embodiment of the present invention can be a light-emitting device with a low driving voltage.

[0061] In addition, the second organic compound is preferably an organic compound containing a phenanthroline skeleton having an electron-donating substituent in addition to the above-described organic compounds. The phenanthroline skeleton easily interacts with metals and the like. By making the second organic compound containing such a phenanthroline skeleton also have an electron-donating group, the electron density of the phenanthroline skeleton increases, and thus it can be further easily interact with a metal or a metal compound. In particular, when a metal of Group 3, Group 11, Group 12, or Group 13 is used as the metal in the metal or metal compound, an increase in the driving voltage can be suppressed, and thus a tandem light-emitting device having good characteristics can be provided.

[0062] Specific examples of the electron-donating group include an alkyl group, an alkoxy group, an aryloxy group, an alkylamino group, an arylamino group, a heterocyclic amino group, and the like. However, the electron-donating group preferably introduced into the phenanthroline ring is not limited thereto. As long as a group capable of increasing the electron density of the phenanthroline ring is introduced into the phenanthroline ring, it can be used as the electron-donating group. In addition, the electron-donating group may be introduced into the phenanthroline ring through an arylene group such as a phenylene group, and the arylene group is preferably a p-phenylene group.

[0063] Structures (300) to (310) show specific examples of the organic compound containing a phenanthroline skeleton having an electron-donating substituent.

[0064] [Chemical formula 2]

[0065] The electron transport layer included in the light-emitting unit on the cathode side has a stacked structure as described above, and the layer on the cathode side in the stack preferably contains a first organic compound containing a triazine skeleton.

[0066] As the first organic compound containing a triazine skeleton, any substance having higher electron transportability than hole transportability can be used, but preferably has an electron mobility of 1×10 when the square root of the electric field strength [V / cm] is 600 - 7 cm 2 / Vs or more, preferably 1×10 -6 cm 2 / Vs or more of an organic compound.

[0067] The first organic compound containing a triazine skeleton is preferably a compound containing a triazine skeleton and an aromatic ring. As the aromatic ring, a monocyclic aromatic ring, a polycyclic aromatic ring, an aromatic ring having an alkyl group as a substituent, an aromatic ring having a fluorine group as a substituent, an aromatic ring having a cyano group as a substituent, and the like are preferably used. The triazine skeleton may also have a substituent other than the above-described aromatic ring, and the aromatic ring may also have a substituent other than the above-described fluorine group, cyano group, or alkyl group. Note that the triazine skeleton is also referred to as a triazine ring, and other skeletons may also be referred to as rings.

[0068] As a monocyclic aromatic ring, aromatic hydrocarbon rings such as benzene ring or heterocyclic rings such as pyrrole ring, pyridine ring, pyrimidine ring, triazine ring can be cited. By having an aromatic ring as a substituent, heat resistance can be improved, specifically, the glass transition temperature (Tg) can be increased, and the effect of improving electron transport property can be obtained, etc.

[0069] As a polycyclic aromatic ring, naphthalene ring, phenanthrene ring, anthracene ring, triphenylene ring, fluorene ring, spirobifluorene ring and other aromatic hydrocarbon rings, carbazole ring, dibenzofuran ring, dibenzothiophene ring, xanthene ring, indolocarbazole ring, indeno[1,2-b]carbazole ring and other heterocyclic rings, etc. Compared with a compound having a monocyclic aromatic ring such as benzene ring, a compound having a polycyclic aromatic ring as a substituent can improve heat resistance, so it is preferred. In addition, in the case of having a ring in which the above polycyclic aromatic ring and an aromatic ring (benzene ring, naphthalene ring, pyridine ring, etc.) are fused as a substituent, heat resistance can be further improved. As a ring in which a polycyclic aromatic ring and an aromatic ring are fused, benzo[b]fluorene ring, benzo[1,2-b]naphtho[2,3-d]furan ring, benzo[x]xanthene ring, benzo[1,2-b]naphtho[2,3-d]thiophene ring, etc. can be cited. By providing a layer containing a compound having high heat resistance near the cathode, thermal damage to the device during high-temperature treatment such as a patterning process after forming the layer or the cathode can be suppressed.

[0070] In addition, as an alkyl group, methyl group, ethyl group, propyl group, tert-butyl group, cyclohexyl group, adamantyl group, etc. can be cited. A first organic compound having an alkyl group as a substituent can be an organic compound having a low refractive index, so that the layer using the first organic compound can have a low refractive index. Therefore, total reflection at the interface between this layer and other layers can be reduced, and thus the light extraction efficiency of a light-emitting device using this layer can be improved. In addition, an organic compound having multiple carbon atoms (preferably three or more, more preferably four or more, further preferably five or more) in the alkyl group can enhance the effect of reducing the refractive index.

[0071] In addition, by also using the above compound having an alkyl group for the hole transport layer, the refractive index of the hole transport layer can be reduced. In particular, by using a compound having a triazine skeleton and an alkyl group for the electron transport layer and a compound having an aromatic amine skeleton and an alkyl group for the hole transport layer, the effect of improving the light extraction efficiency can be enhanced.

[0072] In addition, a layer using a compound having a fluorine group as a substituent can also reduce the refractive index, so it is preferred. In particular, an organic compound having multiple fluorine groups can enhance the effect of reducing the refractive index. It is also effective to use a compound having a fluorine group for both the electron transport layer and the hole transport layer.

[0073] In addition, a compound having a structure in which an aromatic ring is bonded to a plurality of alkyl groups or fluorine groups can further reduce the refractive index of the layer. For example, a structure in which a benzene ring is bonded to two or more tert-butyl groups as substituents can be cited. In addition, a plurality of alkyl groups or fluorine groups can also be bonded to other monocyclic aromatic rings such as a pyridine ring or polycyclic aromatic rings such as a fluorene ring, not limited to a benzene ring. In addition, it is also preferable that a part of the polycyclic aromatic rings (naphthalene ring, fluorene ring, carbazole ring, quinoline ring, xanthene ring, etc.) is bonded to a plurality of alkyl groups or fluorine groups. For example, a structure in which a benzene ring constituting a fluorene ring is bonded to a plurality of tert-butyl groups can be cited.

[0074] In addition, a first organic compound having a cyano group as a substituent can improve electron transport properties and is therefore preferable.

[0075] In addition, as substituents of the first organic compound, it is also preferable to combine a plurality of polycyclic aromatic rings, alkyl groups, fluorine groups, and cyano groups. For example, when having a polycyclic aromatic ring and a cyano group as substituents, both heat resistance and electron transport properties can be improved. In addition, by having a polycyclic aromatic ring and an alkyl group, both heat resistance and light extraction efficiency can be improved. Thus, substituents can be combined according to the required functions.

[0076] In addition, a first organic compound having a plurality of polycyclic aromatic rings as substituents can further improve heat resistance. In this case, the first organic compound preferably contains the above-mentioned aromatic ring and the above-mentioned heteroaromatic ring.

[0077] As specific examples of the first organic compound containing a triazine skeleton, for example, 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), 2-[4-(2-naphthyl)phenyl]-4-phenyl-6-spiro[9H-fluorene-9,9’-[9H]xanthen]-4-yl-1,3,5-triazine (abbreviation: βNP-SFx(4)Tzn), 9,9’-{6-[3-(triphenylsilyl)phenyl]-1,3,5-triazine-2,4-diyl}bis(9H-carbazole) (abbreviation: SiTrzCz2), 2-phenyl-4,6-bis[3-(triphenylsilyl)phenyl]-1,3,5-triazine (abbreviation: mSiTrz), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazine-2-yl]-11,12-dihydro-12-(biphenyl-3-yl)indolo[2,3-a]carbazole (abbreviation: BP-mBPIcz(II)Tzn), 3-{3-[9-(4,6-diphenyl-1,3,5-triazine-2-yl)-2-dibenzofuranyl]phenyl}-9-phenyl-9H-carbazole (abbreviation: mPCPDBfTzn), 9,9’-[6-(biphenyl 4-yl)-2-phenyl-1,3,5-triazine-4,3”-diyl]bis(9H-carbazole) (abbreviation: Cz-pmCzBPTzn), 3-phenyl-9-[4-phenyl-6-(9-phenyl-3-dibenzofuranyl)-1,3,5-triazine-2-yl]-9H-carbazole (abbreviation: PDBf-PCzTzn), 9-[4-(4,6-diphenyl-1,3,5-triazine-2-yl)-2-dibenzothienyl]-2-phenyl-9H-carbazole (abbreviation: PCzDBtTzn), 2,4-diphenyl-6-[3’-(spiro[7H-benzo[c]fluorene-7,9’-[9H]xanthene]-2-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: mSbfxBPTzn), 3′-[4-phenyl-6-(spiro[9H-fluorene-9,9′-[9H]xanthene]-2′-yl)-1,3,5-triazine-2-yl]biphenyl-4-carbonitrile (abbreviation: mpCNBP-SFxTzn), 2,2’-[1,2-naphthalenediylbis(4,1-phenylene)]bis(4,6-diphenyl-1,3,5-triazine) (abbreviation: TznP2N), etc. Organic compounds containing heteroaromatic rings having a triazine skeleton, and particularly preferably TznP2N(100), mSbfxBPTzn(101), mpCNBP-SFxTzn(102), CNBPNPTzn(103), βNP-SFx(4)Tzn(104), mmtBuBP-mDMePyPTzn(105), mBnfBPTzn(106), etc. represented by the following structural formulas (100) to (106). In addition, organic compounds in which the above organic compounds are appropriately deuterated can also be used in the same manner.,

[0078] [Chemical formula 3]

[0079] In addition, the electron transport layer included in the light-emitting unit on the anode side may have the above-mentioned stacked structure or single-layer structure. In the case of having a stacked structure, the layer on the intermediate layer side among the layers included in the stacked structure preferably contains a third organic compound having a triazine skeleton to reduce the driving voltage and power consumption, and preferably contains a fourth organic compound not having a triazine skeleton to appropriately control the electron transport from the intermediate layer.

[0080] In addition, when the first layer contains a Group 1 or Group 2 element, especially lithium or a lithium compound, and a second organic compound containing a phenanthroline skeleton having an electron-donating substituent, a tandem light-emitting device with a lower driving voltage and good reliability can be provided, so it is preferred. Furthermore, when the first layer contains a Group 1 or Group 2 element, especially lithium or a lithium compound, and a second organic compound containing a phenanthroline skeleton having an electron-donating substituent, an increase in the driving voltage can be suppressed when processing the organic compound layer of the light-emitting device by photolithography, so it is preferred.

[0081] In the intermediate layer having the above structure, the second organic compound is particularly preferably an organic compound containing a 1,10-phenanthroline skeleton in the phenanthroline skeleton. Thus, the two nitrogen atoms contained therein can coordinate to a metal, making it easy to interact with a metal or metal compound.

[0082] When an electron-donating group is introduced into the 1,10-phenanthroline skeleton, the electron-donating group is preferably substituted at the 4-position and 7-position of the 1,10-phenanthroline skeleton. By introducing an electron-donating group at the 4-position and 7-position of the 1,10-phenanthroline skeleton, the electron density of the nitrogen atoms at the 1-position and 10-position can be increased, making it easier to interact with a metal or metal compound.

[0083] The first layer may further contain an organic compound different from the second organic compound. This organic compound is preferably an organic compound having electron transport properties. In particular, this organic compound preferably has two or more heteroaromatic rings bonded or fused to each other, and the two or more heteroaromatic rings have a total of three or more heteroatoms. By making the first layer contain such an organic compound, heat resistance and electron transport properties can be improved, etc.

[0084] The second layer preferably contains a fifth organic compound having hole transport properties.

[0085] In addition, the second layer preferably further contains a substance exhibiting acceptor properties. This substance exhibiting acceptor properties is preferably an organic compound exhibiting acceptor properties with respect to the fifth organic compound. As the substance having acceptor properties, an organic compound having a halogen group and / or a cyano group is particularly preferably used, and an organic compound having a fluorine and / or a cyano group is more preferably used. In addition, the total number of the halogen group (fluorine) and the cyano group contained in this organic compound is more preferably 4 or more. In other words, the second layer is preferably a layer containing a halogen, especially fluorine.

[0086] When the second layer contains a fifth organic compound and a substance that exhibits acceptor properties with respect to the fifth organic compound, holes are generated by charge separation. When a voltage is applied between the first electrode and the second electrode, these holes are injected into the light-emitting unit on the cathode side through the fifth organic compound. Thus, a light-emitting device according to one embodiment of the present invention can be a light-emitting device with a low driving voltage.

[0087] The intermediate layer may also include a third layer between the first layer and the second layer.

[0088] The third layer contains a substance having electron-transporting properties, has the function of smoothly transferring electrons between the first layer and the second layer to reduce the driving voltage, and has functions such as reducing the interaction between the first layer and the second layer to improve reliability.

[0089] The LUMO energy level of the electron-transporting substance contained in the third layer is preferably between the LUMO energy level of the acceptor substance in the second layer and the LUMO energy level of the organic compound contained in the layer in contact with the first layer in the light-emitting unit on the anode side (for example, the electron-transporting layer in the light-emitting unit on the anode side).

[0090] In addition, as a specific energy level of the LUMO energy level of the electron-transporting substance for the third layer, it is preferably -5.0 eV or higher, more preferably -5.0 eV or higher and -3.0 eV or lower, more preferably -4.30 eV or higher and -3.00 eV or lower, and even more preferably -4.30 eV or higher and -3.30 eV or lower, so that an increase in the driving voltage can be suppressed. In addition, as the electron-transporting substance for the third layer, a phthalocyanine-based material or a metal complex having a metal-oxygen bond and an aromatic ligand is preferably used.

[0091] In addition, the thickness of the third layer is preferably 1 nm or more and 10 nm or less, and more preferably 2 nm or more and 5 nm or less, whereby an increase in the driving voltage can be suppressed.

[0092] The light-emitting device of the present invention having the above structure can be a light-emitting device with high current efficiency, less energy loss, and good characteristics. In addition, a display device according to one embodiment of the present invention using such a light-emitting device can be a display device with low power consumption, high reliability, and good visibility capable of displaying at high brightness.

[0093] Next, a light-emitting device according to one embodiment of the present invention will be described in detail with reference to the accompanying drawings. Figure 1AThe light-emitting device 130 showing one embodiment of the present invention. The light-emitting device according to one embodiment of the present invention is a tandem-type light-emitting element including an organic compound layer 103 (also referred to as an EL layer) between a first electrode 101 including an anode and a second electrode 102 including a cathode. The organic compound layer 103 includes a first light-emitting unit 501 having a first light-emitting layer 113_1, a second light-emitting unit 502 having a second light-emitting layer 113_2 and a second electron transport layer 114_2 (a stack of a second electron transport layer 114_2a and a second electron transport layer 114_2b), and an intermediate layer 116. In addition, the first light-emitting unit may also include a first electron transport layer 114_1 between the first light-emitting layer 113_1 and the intermediate layer 116.

[0094] In the light-emitting device 130, the second electron transport layer 114_2 has a stacked structure of a second electron transport layer 114_2a and a second electron transport layer 114_2b. The second electron transport layer 114_2b is located between the second electron transport layer 114_2a and the cathode. In addition, the intermediate layer 116 has a second organic compound containing a phenanthroline skeleton.

[0095] The second electron transport layer 114_2b preferably contains a first organic compound having a triazine skeleton, thereby reducing power consumption. In addition, the second electron transport layer 114_2b containing the first organic compound having a triazine skeleton preferably contacts the second electrode 102, thereby improving electron injectability to reduce the driving voltage and power consumption.

[0096] In the present embodiment, a light-emitting device including one intermediate layer 116 and two light-emitting units is taken as an example for description, but a light-emitting device including n (n is an integer of 1 or more) layers of intermediate layers and n + 1 layers of light-emitting units may also be adopted. For example, Figure 1B The shown light-emitting device 130 is an example of a tandem light-emitting device with n = 2 including a first light-emitting unit 501, a first intermediate layer 116_1, a second light-emitting unit 502, a second intermediate layer 116_2, and a third light-emitting unit 503.

[0097] The first light-emitting unit 501 and the second light-emitting unit 502 may also include other functional layers other than the above-mentioned light-emitting layer and electron transport layer, etc. In Figure 1A it, in the first light-emitting unit 501, a hole injection layer 111 and a first hole transport layer 112_1 are further provided in addition to the first light-emitting layer 113_1 and the first electron transport layer 114_1. In the second light-emitting unit 502, a second hole transport layer 112_2 is further provided in addition to the second light-emitting layer 113_2 and the second electron transport layer 114_2. However, the structure of the organic compound layer 103 of the present invention is not limited thereto, and any of the above layers may not be provided, or other layers may be provided. As other layers, typically there are a carrier blocking layer, an exciton blocking layer, etc.

[0098] The first electrode 101 is an electrode including an anode. The first electrode 101 may also have a laminated structure, and in this case, the layer in contact with the organic compound layer 103 is used as the anode. The anode is preferably formed of a metal, an alloy, a 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), 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 sputtering, sol-gel methods or the like can also be applied for formation. As an example of the formation 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), etc. can be cited. In addition, graphene can also be used as a material for the anode. In addition, by using the composite material constituting the second layer 117 in the above-mentioned intermediate layer 116 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.

[0099] The hole injection layer 111 is in contact with the anode and has a function of facilitating the injection of holes into the organic compound layer 103 (the first light-emitting unit 501). Phthalocyanine compounds or complex compounds such as phthalocyanine (abbreviation: H2Pc), copper phthalocyanine (abbreviation: CuPc), etc.; 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.

[0100] In addition, the hole injection layer 111 can also be formed using a substance with an electron-accepting property. As the substance with an accepting property, organic compounds having an electron-withdrawing group (halogen group, cyano group, etc.) can be used, and examples include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyrene-2-ylidene) malononitrile, etc. In particular, compounds such as HAT-CN in which an electron-withdrawing group is bonded to a condensed aromatic ring having a plurality of heteroatoms are thermally stable, so they are preferred. In addition, [3]axylene derivatives having an electron-withdrawing group (especially a halogen group such as a fluorine group, a cyano group) have a very high electron-accepting property, so they 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-cyclopropanetriyl tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzyl cyanide], α,α',α''-1,2,3-cyclopropanetriyl tris[2,3,4,5,6-pentafluorobenzyl cyanide], etc. As the substance with an accepting 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. In addition, phthalocyanine compounds or complexes such as phthalocyanine (abbreviation: H2Pc), copper phthalocyanine (abbreviation: CuPc), etc.; 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) / poly(styrenesulfonic acid) (abbreviation: PEDOT / PSS) can be used to form the hole injection layer 111. The substance with an accepting property can extract electrons from the adjacent hole transport layer (or hole transport material) by applying an electric field.

[0101] In addition, the hole injection layer 111 is preferably formed of a composite material containing the above-mentioned material with an accepting property and a substance with a hole-transporting property.

[0102] As a substance having hole transport properties for a composite material, various organic compounds such as aromatic amine compounds, heteroaromatic compounds, aromatic hydrocarbons, high molecular compounds (oligomers, dendrimers, polymers, etc.) can be used. As a substance having hole transport properties for a composite material, it is preferable to use a substance having a hole mobility of 1×10 -6 cm 2 / Vs or more. The substance having hole transport properties for a composite material is preferably a compound containing a fused aromatic hydrocarbon ring or a π-electron-rich heteroaromatic ring. As the fused aromatic hydrocarbon ring, an anthracene ring, a naphthalene ring, etc. are preferable. 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 preferable, 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 preferable.

[0103] Such a substance having hole transport 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 containing a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine containing 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 substances having hole transport properties are substances including N,N-bis(4-biphenyl)amino, a light-emitting device having a long lifetime can be manufactured, so they are preferable.

[0104] As the above-mentioned hole-transporting material, 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-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophene-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4''-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthyl-2-yl)-triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenyl)-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-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-1-amine, 9-[3-(Triphenylsilyl)phenyl]-3,9'-bi-9H-carbazole (abbreviation: PSiCzCz), 9'-Phenyl-9'H-9,3':6',9''-tricarbazole (abbreviation: PSiCzGI), etc.

[0105] In addition, as a substance having hole-transporting properties, the following aromatic amine compounds can also be used: 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.

[0106] 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.

[0107] In addition, among substances having acceptor properties, organic compounds having acceptor properties can be easily formed by vapor deposition, so they are materials that are easy to use.

[0108] The hole transport layer (the first hole transport layer 112_1, the second hole transport layer 112_2) is formed by including an organic compound having hole-transporting properties. The organic compound having hole-transporting properties preferably has a hole mobility of 1×10 -6 cm 2 / Vs or more.

[0109] Examples of the hole-transporting material described above include compounds having an aromatic amine skeleton such as 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), etc.;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'-bi(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, 9-[3-(triphenylsilyl)phenyl]-3,9'-bi-9H-carbazole (abbreviation: PSiCzCz) and other compounds with a carbazole skeleton;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 other compounds having a thiophene skeleton; and 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) and other compounds having a furan skeleton. Among them, compounds having an aromatic amine skeleton and compounds having a carbazole skeleton have good reliability and high hole transport properties and contribute to reducing the driving voltage, so they are preferred. In addition, organic compounds cited as hole-transporting substances used as composite materials for the hole injection layer 111 can also be suitably used as materials constituting the hole transport layer. In addition, organic compounds in which the above organic compounds are appropriately deuterated can also be used in the same manner.

[0110] In addition, the first hole transport layer 112_1 and the second hole transport layer 112_2 preferably contain organic compounds having the same skeleton, and more preferably the same compound.

[0111] The light-emitting layer (the first light-emitting layer 113_1 and the second light-emitting layer 113_2) preferably contains a light-emitting center substance and a host material. In addition, the light-emitting layer may also contain other materials at the same time.

[0112] In addition, the first light-emitting layer 113_1 and the second light-emitting layer 113_2 are preferably light-emitting layers that emit light of similar colors. For example, in a display device, in order to display full color, pixels of red, green, and blue are mostly used. In a light-emitting device for a red pixel, both the first light-emitting layer 113_1 and the second light-emitting layer 113_2 emit red light. In a light-emitting device for a green pixel, both light-emitting layers emit green light. In a light-emitting device for a blue pixel, both light-emitting layers emit blue light. At this time, the light-emitting center substance contained in the first light-emitting layer 113_1 and the light-emitting center substance contained in the second light-emitting layer 113_2 are preferably compounds whose difference in the maximum peak wavelength of their emission spectra is 30 nm or less, more preferably 20 nm or less, and further preferably 10 nm or less. In addition, more preferably, the light-emitting center substance contained in the first light-emitting layer 113_1 is the same as the light-emitting center substance contained in the second light-emitting layer 113_2.

[0113] The light-emitting center material can be a fluorescent light-emitting material, a phosphorescent light-emitting material, a material exhibiting thermally activated delayed fluorescence (TADF), or other light-emitting materials.

[0114] In the light-emitting layer, as the fluorescent light-emitting material that can be used as the light-emitting center material, for example, the following materials can be cited. Note that, in addition, other fluorescent light-emitting materials can also be used.

[0115] 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'-diphenyldiphenylethylene-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-butylperylene (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] -2,7,10,15 - tetraamine (abbreviation: DBC1), Coumarin 30, 9,10 - diphenyl - 2 - [N - phenyl - N - (9 - phenyl - carbazol - 3 - yl) - amino] - anthracene (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’ - tetra(4 - methylphenyl)tetracene - 5,11 - diamine (abbreviation: p - mPhTD), 7,14 - diphenyl - N,N,N’,N’ - tetra(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), N,N'-diphenyl-N,N'-bis[(9-phenyl-9H-carbazol-2-yl)]naphtho[2,3-b;6,7-b']dibenzofuran-3,10-diamine (abbreviation: 3,10PCA2Nbf(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']dibenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02), etc. In particular, fused aromatic diamine compounds represented by pyrene diamine compounds such as 1,6FLPAPrn, 1,6mMemFLPAPrn, 1,6BnfAPrn-03, etc. have good hole trapping properties and high luminous efficiency or good reliability, so they are preferred.,

[0116] In the light-emitting layer, as the phosphorescent light-emitting material that can be used as the light-emitting center substance, for example, the following substances can be cited.

[0117] Examples include: tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN 2Phenyl-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]) and other organometallic iridium complexes with 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 with 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]), tris(2-{1-[2,6-bis(1-methylethyl)phenyl]-1H-imidazol-2-yl-κN3}-4-cyanophenyl-κC)iridium(III) (abbreviation: CNImIr) and other organometallic iridium complexes with an imidazole skeleton; tris[(6-tert-butyl-3-phenyl-2H-imidazo[4,5-b]pyrazin-1-yl-κC2)phenyl-κC]iridium(III) (abbreviation: [Ir(cb)3]) and other organometallic complexes with a benzimidazolylidene skeleton; 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’Organic metal iridium complexes such as iridium(III) acetylacetonate (abbreviation: FIracac) with phenylpyridine derivatives having an electron-withdrawing group as ligands; and platinum complexes such as (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-(4-tert-butyl-2-pyridyl-κN)carbazole-2,1-diyl-κC1)platinum(II) (abbreviation: PtON-TBBI), etc. 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. In addition, compounds in which a part of the hydrogen possessed by these compounds is deuterium can also be used.

[0118] 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-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm)2(acac)]), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(mpmppm)2(acac)]), (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2(acac)]) and other organic metal 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)]) and other organic metal 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-κN 2 )phenyl-κC]iridium(III) (abbreviation: Ir(5mppy-d3)2(mbfpypy-d3)), {2-(methyl-d3)-8-[4-(1-methylethyl-1-d)-2-pyridinyl-κN]benzofuro[2,3-b]pyridin-7-yl-κC}bis{5-(methyl-d3)-2-[5-(methyl-d3)-2-pyridinyl-κN]phenyl-κC}iridium(III) (abbreviation: Ir(5mtpy-d6)2(mbfpypy-iPr-d4)), [2-d3-methyl-(2-pyridinyl-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)), [2-(4-d3-methyl-5-phenyl-2-pyridinyl-κN 2 )phenyl-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN 2Phenyl-κC]iridium(III) (abbreviation: [Ir(5mppy-d3)2(mdppy-d3)]), [2-methyl-(2-pyridyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy)2(mbfpypy)]), [2-(4-methyl-5-phenyl-2-pyridyl-κN)phenyl-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium (abbreviation: [Ir(ppy)2(mdppy)]), tris{2-[5-(methyl-d3)-4-phenyl-2-pyridyl-κN]phenyl-κC}iridium(III) (abbreviation: Ir(5m4dppy-d3)) and other organometallic iridium complexes with a pyridine skeleton; and tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: [Tb(acac)3(Phen)]) and other rare earth metal complexes. The above substances are mainly compounds that exhibit green phosphorescence and have a luminescence peak in the wavelength range of 500 nm to 600 nm. In addition, organometallic iridium complexes with a pyrimidine skeleton are particularly preferred because they have particularly excellent reliability and luminescence efficiency. In addition, compounds in which a part of the hydrogen of these compounds is deuterium can also be used.

[0119] In addition, examples include: (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]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-di(naphthalen-1-yl)pyrimidinato](dineopentanoylmethanato)iridium(III) (abbreviation: [Ir(d1npm)2(dpm)]) and other organometallic iridium complexes with a pyrimidine skeleton; (acetylacetonato)bis(2,3,5-triphenylpyrazinato)iridium(III) (abbreviation: [Ir(tppr)2(acac)]), bis(2,3,5-triphenylpyrazinato)(dineopentanoylmethanato)iridium(III) (abbreviation: [Ir(tppr)2(dpm)]), (acetylacetonato)bis[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’)Organometallic iridium complexes with a pyridine skeleton such as iridium(III) acetylacetonate (abbreviation: [Ir(piq)2(acac)]), (3,7 - diethyl - 4,6 - nonanedionato - κO4,κO6)bis[2,4 - dimethyl - 6 - [7 - (1 - methylethyl)-1 - isoquinolinyl - κN]phenyl - κC]iridium(III), (3,7 - diethyl - 4,6 - nonanedionato - κO4,κO6)bis[2,4 - dimethyl - 6 - [5 - (1 - methylethyl)-2 - quinolinyl - κN]phenyl - κC]iridium(III); 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 - thiophenecarbonyl)-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. In addition, compounds in which a part of the hydrogen of these compounds is deuterium can also be used.

[0120] In addition, in one aspect of the present invention, by using a deuterated compound as the luminescent center substance, the luminous efficiency is improved. Therefore, the luminescent center substance is preferably a deuterated material.

[0121] In addition to the above phosphorescent compounds, known phosphorescent compounds can also be selected and used.

[0122] Fullerenes and their derivatives, acridine and its derivatives, and eosin derivatives can be used as TADF materials. In addition, metal - containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd) etc. can also be mentioned. As such metal - containing porphyrins, 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(Copro III - 4Me)), octaethylporphyrin - tin fluoride complex (SnF2(OEP)), etioporphyrin - tin fluoride complex (SnF2(Etio I)), and octaethylporphyrin - platinum chloride complex (PtCl2OEP) etc. represented by the following structural formulas can also be mentioned.

[0123] [Chemical Formula 4]

[0124] 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. Such a heterocyclic 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 containing a π-deficient heteroaromatic ring, a pyridine skeleton, a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), and a triazine skeleton are stable and have good reliability, so they are preferred. In particular, a benzofuranopyrimidine skeleton, a benzothienopyrimidine skeleton, a benzofuranopyrazine skeleton, and a benzothienopyrazine skeleton have high acceptability and good reliability, so they are preferred. In addition, in the skeleton having a π-rich heteroaromatic ring, an acridine skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a furan skeleton, a thiophene skeleton, and a pyrrole skeleton are stable and have good reliability, so it is preferred to have at least one of the above skeletons. In addition, a dibenzofuran skeleton is preferably used as the furan skeleton, and a dibenzothiophene skeleton is preferably used as the thiophene skeleton. 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, both the electron-donating property of the π-rich heteroaromatic ring and the electron-accepting property of the π-deficient heteroaromatic ring are 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 type skeleton, an 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 and boranthrene, an aromatic ring, a 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 type skeleton and the π-excessive electron type skeleton can be used in place of the π-deficient electron type heteroaromatic ring and the π-excessive electron type heteroaromatic ring.

[0125] [Chemical formula 5]

[0126] In addition, as the TADF material, a TADF material in which a singlet excited state and a triplet excited state are in a thermal equilibrium state can also be used. Since this TADF material has a short luminescence lifetime (excitation lifetime), 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.

[0127] [Chemical formula 6]

[0128] 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 luminescence.

[0129] 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.

[0130] Note that as an index of the T1 energy level, a phosphorescence spectrum observed at a low temperature (for example, 77K to 10K) can be used. Regarding the TADF material, preferably, when the wavelength energy of the extrapolated line obtained by drawing a tangent at the tail on the short-wavelength side of the fluorescence spectrum is defined as the S1 energy level and the wavelength energy of the extrapolated line obtained by drawing a tangent at the tail on the short-wavelength side of the phosphorescence spectrum is defined as the T1 energy level, the difference between S1 and T1 is 0.3 eV or less, and more preferably 0.2 eV or less.

[0131] In addition, when a TADF material is used as the luminescent 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.

[0132] As the host material of the light-emitting layer, various charge transport materials such as materials having electron-transporting properties and / or materials having hole-transporting properties, and the above-mentioned TADF materials can be used.

[0133] As the material having hole-transporting properties, an organic compound having an amine skeleton or a π-electron-rich heteroaromatic ring skeleton is preferably used. As the π-electron-rich heteroaromatic ring, a fused aromatic ring containing at least any one of an acridine skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a furan skeleton, a thiophene skeleton, and a pyrrole skeleton is preferable, 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 preferable.

[0134] Such a material 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 containing a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine containing 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 materials having hole-transporting properties are organic compounds including N,N-bis(4-biphenyl)amino, a light-emitting device having a long lifetime can be manufactured, so they are preferable.

[0135] As such an organic compound, for example, the following organic compounds are preferably used: 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), 3,9-bis(9-phenyl-9H-carbazol-3-yl)-9H-carbazole (abbreviation: PCCzPC), 9-(biphenyl-4-yl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: PCCzBP), 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, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9’-spirobi-9H-fluorene-1-amine, 9-[3-(triphenylsilyl)phenyl]-3,9’-bicarbazole (abbreviation: PSiCzCz), 9’-phenyl-9’H-9,3’:6’,9”-tricarbazole (abbreviation: PSiCzGI) and other compounds with a carbazole backbone; 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 other compounds with a thiophene backbone; and 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) and other compounds with a furan backbone. Among them, compounds with an aromatic amine backbone or a carbazole backbone have good reliability and high hole transportability and help to reduce the driving voltage, so they are preferred. In addition, organic compounds cited as examples of materials with hole transportability can also be used.,

[0136] As the material having electron transporting property, an organic compound containing a π-deficient heteroaromatic ring is preferably used. As the organic compound containing a π-deficient heteroaromatic skeleton, for example, an organic compound containing a heteroaromatic ring having a triazole skeleton, an organic compound containing a heteroaromatic ring having a pyridine skeleton, an organic compound containing a heteroaromatic ring having a diazine skeleton, and an organic compound containing a heteroaromatic ring having a triazine skeleton can be cited.

[0137] Among them, an organic compound containing a heteroaromatic ring having a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), an organic compound containing a heteroaromatic ring having a pyridine skeleton, or an organic compound containing a heteroaromatic ring having a triazine skeleton has good reliability, and thus is preferred. In particular, an organic compound containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and an organic compound containing a heteroaromatic ring having a triazine skeleton have high electron transporting property, which helps to reduce the driving voltage. In addition, a benzofuranopyrimidine skeleton, a benzothienopyrimidine skeleton, a benzofuranopyrazine skeleton, and a benzothienopyrazine skeleton have high acceptor property and high reliability, and thus are preferred.

[0138] As an organic compound containing a π-deficient heteroaromatic ring skeleton, for example, the following organic compounds are preferably used: 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) and other organic compounds having an oxazole skeleton; 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-[3-(2-triphenylene)phenyl]-1,10-phenanthroline (abbreviation: mTpPPhen), 2-phenyl-9-(2-triphenylene)-1,10-phenanthroline (abbreviation: Ph-TpPhen), 2-[4-(9-phenanthryl)-1-naphthyl]-1,10-phenanthroline (abbreviation: PnNPhen), 2-[4-(2-triphenylene)phenyl]-1,10-phenanthroline (abbreviation: pTpPPhen) and other heteroaromatic-containing organic compounds having a pyridine skeleton; 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3’-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3’-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4’-(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]dibenz[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-(dibenzothiophen-4-yl)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), 8-(1,1':4',1''-terphenyl-3-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm) and other organic compounds 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), 2-[4-(2-naphthyl)phenyl]-4-phenyl-6-spiro[9H-fluorene-9,9’-[9H]xanthene]-4-yl-1,3,5-triazine (abbreviation: βNP-SFx(4)Tzn), 9,9’-{6-[3-(triphenylsilyl)phenyl]-1,3,5-triazine-2,4-diyl}bis(9H-carbazole) (abbreviation: SiTrzCz2), 2-phenyl-4,6-bis[3-(triphenylsilyl)phenyl]-1,3,5-triazine (abbreviation: mSiTrz), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazin-2-yl]-11,12-dihydro-12-(biphenyl-3-yl)indolo[2,3-a]carbazole (abbreviation: BP-mBPIcz(II)Tzn), 3-{3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]phenyl}-9-phenyl-9H-carbazole (abbreviation: mPCPDBfTzn), 9,9’-[6-(biphenyl 4-yl)-2-phenyl-1,3,5-triazine-4,3”-diyl]bis(9H-carbazole) (abbreviation: Cz-pmCzBPTzn), 3-phenyl-9-[4-phenyl-6-(9-phenyl-3-dibenzofuranyl)-1,3,5-triazin-2-yl]-9H-carbazole (abbreviation: PDBf-PCzTzn), 9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzothienyl]-2-phenyl-9H-carbazole (abbreviation: PCzDBtTzn), and other organic compounds containing heteroaromatic rings with a triazine skeleton. In addition, organic compounds containing heteroaromatic rings with a diazine skeleton, organic compounds containing heteroaromatic rings with a pyridine skeleton, or organic compounds containing heteroaromatic rings with a triazine skeleton have high reliability, so they are preferred. In particular, organic compounds containing heteroaromatic rings with a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing heteroaromatic rings with a triazine skeleton have high electron transport properties, which helps to reduce the driving voltage.,

[0139] As the TADF material that can be used as the host material, the same materials as those exemplified above as the TADF materials that can be used as the light-emitting center substance can be used. When a 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 energy is transferred to the light-emitting substance, thereby improving the luminous efficiency of the light-emitting device. At this time, the TADF material is used as the energy donor and the light-emitting substance is used as the energy acceptor.

[0140] This is very effective when the above light-emitting substance is a fluorescent light-emitting substance. 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 light-emitting substance. In addition, the T1 energy level of the TADF material is preferably higher than the S1 energy level of the fluorescent light-emitting substance. Therefore, the T1 energy level of the TADF material is preferably higher than the T1 energy level of the fluorescent light-emitting substance.

[0141] 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 light-emitting substance. Thereby, the excitation energy is smoothly transferred from the TADF material to the fluorescent light-emitting substance, and light emission can be obtained efficiently, so it is preferable.

[0142] In order to efficiently generate singlet excitation energy from triplet excitation energy through reverse intersystem crossing, it is preferable to generate carrier recombination in the TADF material. In addition, it is preferable that the triplet excitation energy generated in the TADF material does not transfer to the triplet excitation energy of the fluorescent light-emitting substance. For this purpose, the fluorescent light-emitting substance preferably has a protecting group around the lumophore (the skeleton that causes light emission) of the fluorescent light-emitting substance. As this protecting group, a substituent without a π bond is preferable, 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 10 or less carbon atoms, a trialkylsilyl group having 3 or more and 10 or less carbon atoms can be cited, and it is more preferable to have 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 separate the TADF material and the lumophore of the fluorescent light-emitting substance from each other. Here, the lumophore refers to the atomic group (skeleton) that causes light emission in the fluorescent light-emitting substance. The lumophore is preferably a skeleton having a π bond, preferably contains an aromatic ring, and preferably has a fused aromatic ring or a fused heteroaromatic ring. As the above lumophore, 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, a 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, having a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, Fluorescent luminescent substances with a skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, and a naphthobisbenzofuran skeleton have a high fluorescence quantum yield, so they are preferred.

[0143] When a fluorescent luminescent substance is used as a luminescent center 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 luminescent substance, a luminescent 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, so it is 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 carbazole, the HOMO is about 0.1 eV shallower than that of the carbazole skeleton and it is easier to inject holes, so it is more preferred. In particular, when the host material has a dibenzocarbazole skeleton, the HOMO is about 0.1 eV shallower than that of the carbazole skeleton. Not only is it easy to inject holes, but also the hole transport property and heat resistance are improved, so it is preferred. Therefore, as the host material, a substance having both a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzocarbazole skeleton or a dibenzocarbazole skeleton) is further preferred. 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-dibenz[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 properties, so they are preferred.

[0144] 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 (the first light-emitting layer 113_1 and the second light-emitting layer 113_2), 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.

[0145] 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.

[0146] In addition, these mixed materials can also be used to form an exciplex. By selecting the mixed materials in such a way as to form an exciplex that emits light with a wavelength overlapping 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.

[0147] Note that at least one of the materials forming the exciplex can be a phosphorescent light-emitting substance. Thereby, triplet excitation energy can be efficiently converted into singlet excitation energy through reverse intersystem crossing.

[0148] Regarding the 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 characteristics (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV) measurement.

[0149] Note that the formation of an exciplex can be confirmed, for example, by comparing the emission spectra of a hole-transporting material, the emission spectra of an electron-transporting material, and the emission spectra of a mixed film formed by mixing these materials. When it is observed that the emission spectrum of the mixed film is shifted 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, by comparing the transient photoluminescence (PL) of a hole-transporting material, the transient PL of an electron-transporting material, and the transient PL of a mixed film formed by mixing these materials, when it is observed that the transient PL lifetime of the mixed film has a long-lived component or the ratio of the delayed component becomes larger 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 hole-transporting material, the transient EL of an electron-transporting material, 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.

[0150] As the first electron transport layer 114_1 and the second electron transport layer 114_2, any material with higher electron transportability than hole transportability can be used, but it is a layer containing a material with electron transportability. As the material with electron transportability, preferably, when 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. As the above organic compound, an organic compound containing a π-deficient heteroaromatic ring is preferably used. As the organic compound containing a π-deficient heteroaromatic ring, for example, any one or more of an organic compound containing a heteroaromatic ring having a triazole skeleton, an organic compound containing a heteroaromatic ring having a pyridine skeleton, an organic compound containing a heteroaromatic ring having a diazine skeleton, and an organic compound containing a heteroaromatic ring having a triazine skeleton are preferably used.

[0151] As the organic compound having electron transporting property that can be used for the above-mentioned first electron transporting layer 114_1 and second electron transporting layer 114_2, an organic compound that can be similarly used as the organic compound having electron transporting property that can be used as the host material in the above-mentioned first light emitting layer 113_1 and second light emitting layer 113_2 can be used. In particular, an organic compound containing a heteroaromatic ring having a diazine skeleton, an organic compound containing a heteroaromatic ring having a pyridine skeleton, or an organic compound containing a heteroaromatic ring having a triazine skeleton has good reliability, and thus is preferred. In particular, an organic compound containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and an organic compound containing a heteroaromatic ring having a triazine skeleton have high electron transporting property, which helps to reduce the driving voltage.

[0152] Note that the first electron transporting layer 114_1 may have a stacked structure or may not have a stacked structure. When having a stacked structure, a light emitting device with high current efficiency, lower power consumption and good characteristics can be provided. In the case of having a single-layer structure, the number of deposition processing chambers is small, so it is advantageous from the viewpoint of manufacturing cost. In the case of having a stacked structure, the layer on the intermediate layer side among the layers included in the stacked structure preferably contains a third organic compound having a triazine skeleton to reduce the driving voltage and power consumption, and preferably contains a fourth organic compound not having a triazine skeleton to appropriately control the electron transport from the intermediate layer.

[0153] As described above, the second electron transporting layer 114_2 has a stacked structure. In Figure 1A it, the second electron transporting layer 114_2 has a stacked structure of a second electron transporting layer 114_2a and a second electron transporting layer 114_2b. The second electron transporting layer 114_2b is located between the second electron transporting layer 114_2a and the cathode. The second electron transporting layer 114_2b preferably contacts the second electrode 102, thereby improving the electron injection property to reduce the driving voltage and power consumption.

[0154] Note that the second electron transporting layer 114_2b preferably has a first organic compound containing a triazine skeleton. As described above, the second electron transporting layer 114_2b preferably contacts the second electrode 102. More preferably, the second electron transporting layer 114_2b having a first organic compound containing a triazine skeleton contacts the second electrode 102, thereby improving the electron injection property to reduce the driving voltage and power consumption. The detailed content has been described above and the repeated description is omitted.

[0155] In addition, the first electron transport layer 114_1 preferably has an organic compound containing a triazine skeleton to reduce power consumption. In particular, the organic compound containing a triazine skeleton in the first electron transport layer 114_1 is preferably the same as the first organic compound containing a triazine skeleton in the second electron transport layer 114_2b, thereby suppressing the complication of manufacturing equipment and being advantageous in terms of raw material procurement cost. In addition, when the first electron transport layer 114_1 has a stacked structure, the layer in contact with the intermediate layer 116 preferably has an organic compound containing a triazine skeleton.

[0156] In addition, when the first electron transport layer 114_1 has a stacked structure, by making the layer in contact with the intermediate layer 116 have an organic compound not containing a triazine skeleton, the carrier transport property can be easily controlled, and thus a light-emitting device with good characteristics can be provided. As the organic compound not containing a triazine skeleton, an organic compound containing a heteroaromatic ring having a pyridine skeleton or an organic compound containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton is preferably used. In addition, the organic compound not containing a triazine skeleton is preferably an organic compound having at least one of a pyrimidine skeleton, an imidazole skeleton, and an anthracene skeleton. For example, by using an organic compound having a pyrimidine skeleton and an anthracene skeleton or an organic compound having an imidazole skeleton and an anthracene skeleton, the carrier transport property can be further easily controlled, so it is preferred.

[0157] The intermediate layer 116 has a second organic compound containing a phenanthroline skeleton. As Figure 1A shown, the intermediate layer 116 preferably includes a first layer 119 having a second organic compound containing a phenanthroline skeleton. In addition, the intermediate layer 116 preferably includes a second layer 117 containing a fifth organic compound having hole transport property and a substance having an acceptor property. In addition, the second layer 117 is closer to the second electrode 102 side than the first layer 119. In addition, the intermediate layer 116 may also include a third layer 118 between the first layer 119 and the second layer 117.

[0158] The details of the first layer have been described above and repeated descriptions are omitted.

[0159] In addition, the first layer 119 may also contain an organic compound having electron transport property. As the organic compound having electron transport property that can be used as this organic compound, an organic compound that can be similarly used as the organic compound having electron transport property that can be used as the host material in the above-mentioned first light-emitting layer 113_1 and second light-emitting layer 113_2 can be used. In addition, as this organic compound, an organic compound having two or more heteroaromatic rings bonded or fused to each other and the two or more heteroaromatic rings containing three or more heteroatoms in total is preferably used, whereby the resistance to photolithography can be further improved and the rise of the driving voltage can be suppressed.

[0160] Note that the first layer 119 may have a laminated structure including a layer containing an organic compound and a layer containing a metal or a metal compound located closer to the cathode side than the layer containing the organic compound, or may be a mixed layer of an organic compound and a metal or a metal compound. When the first layer is a mixed layer, the deposition processing chamber is less, the manufacturing cost is reduced, and it helps to improve the stability of the light-emitting device, so it is preferred.

[0161] In the case where an organic compound and a metal or a metal compound are mixed, when the first layer 119 is analyzed in the thickness direction, the distribution of the organic compound and the distribution of the metal or the metal compound show substantially the same trend. That is, when the distribution of the organic compound is fixed, the distribution of the metal or the metal compound is also substantially fixed. In the laminated structure of the layer containing an organic compound and the layer containing a metal or a metal compound, sometimes the metal or the metal compound diffuses from the layer containing the metal or the metal compound and is detected in a region outside the layer, but since it shows a distribution different from the distribution of the organic compound, the analysis results of diffusion and mixing can be distinguished.

[0162] The second layer 117 preferably contains a fifth organic compound having hole-transporting properties. In addition, the second layer 117 preferably further contains a substance exhibiting an acceptor property, and the substance exhibiting an acceptor property is preferably an organic compound exhibiting an acceptor property with respect to the fifth organic compound.

[0163] In the case where the second layer 117 contains a fifth organic compound and a substance exhibiting an acceptor property with respect to the fifth organic compound, holes are generated by charge separation, and when a voltage is applied between the first electrode 101 and the second electrode 102, the holes are injected into the first light-emitting unit 501 on the cathode side through the fifth organic compound. Thus, the light-emitting device 130 according to one embodiment of the present invention can be a light-emitting device with a low driving voltage.

[0164] As the fifth organic compound having hole-transporting properties, various organic compounds such as aromatic amine compounds, heteroaromatic compounds, aromatic hydrocarbons, and polymer compounds (oligomers, dendrimers, polymers, etc.) can be used. As the fifth organic compound, it is preferable to use an organic compound having a hole mobility of 1×10 -6 cm 2 / Vs or more. In addition, the fifth organic compound is preferably a compound containing a condensed aromatic hydrocarbon ring or a π-electron-rich heteroaromatic ring. As the condensed aromatic hydrocarbon ring, an anthracene ring, a naphthalene ring, etc. are preferable. In addition, as the π-electron-rich heteroaromatic ring, a condensed aromatic ring containing at least one of a pyrrole skeleton, a furan skeleton, and a thiophene skeleton is preferable, and specifically, a carbazole ring, a dibenzothiophene ring, or a ring in which these rings are further condensed with an aromatic ring or a heteroaromatic ring is preferable.

[0165] Such an organic compound having hole-transporting properties is more preferably any one of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton. In particular, it may be an aromatic amine having a substituent containing a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine containing a naphthalene ring, or an aromatic monoamine in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group. 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 lifespan can be manufactured, so they are preferred.

[0166] As the above-mentioned organic compound having hole-transporting properties, specifically, the organic compounds exemplified as the organic compounds having hole-transporting properties that can be used for the hole injection layer 111 can be used in the same manner.

[0167] As a substance having an acceptor property, for example, the substances exemplified as the organic compounds having an acceptor property that can be used for the hole injection layer 111 can be used in the same manner. In particular, an organic compound having a halogen group and / or a cyano group is preferably used, and an organic compound having a fluorine and / or a cyano group is more preferably used. In addition, the total number of halogen groups (fluorine) and cyano groups contained in the organic compound is more preferably 4 or more. Examples of the organic compound having a halogen group and / or a cyano group include: α,α’,α”-1,2,3-cyclopropanetriyltri[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α’,α”-1,2,3-cyclopropanetriyltri[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], α,α’,α”-1,2,3-cyclopropanetriyltri[2,3,4,5,6-pentafluorobenzeneacetonitrile], and the like.

[0168] In addition, the material having an acceptor property preferably has an electron acceptor property with respect to the fifth organic compound having hole-transporting properties. When the material having an acceptor property has an electron acceptor property with respect to the fifth organic compound, charge separation occurs, and the second layer 117 can be used as a charge generation layer and as an intermediate layer of a tandem light-emitting device. In addition, in the second layer 117, a signal observed by electron spin resonance is preferably observed. For example, the spin density due to the signal observed around a g value of 2.00 is preferably 1×10 17 spins / cm 3 or more, more preferably 1×10 18 spins / cm 3 or more, and further preferably 1×10 19 spins / cm 3 or more.

[0169] The third layer 118 contains a substance with electron-transporting properties and has functions such as preventing the interaction between the first layer 119 and the second layer 117, smoothly conducting electron transfer to reduce the driving voltage, and reducing the interaction between the first layer 119 and the second layer 117 to improve reliability, etc.

[0170] The LUMO energy level of the substance with electron-transporting properties contained in the third layer 118 is preferably between the LUMO energy level of the substance with acceptor properties in the second layer 117 and the LUMO energy level of the organic compound contained in the layer in the anode-side light-emitting unit that contacts the first layer 119 ( Figure 1A the first electron transport layer 114_1 in the first light-emitting unit 501).

[0171] Specifically, the LUMO energy level of the substance with electron-transporting properties for the third layer 118 is -5.0 eV or more, preferably -5.0 eV or more and -3.0 eV or less, more preferably -4.30 eV or more and -3.00 eV or less, and further preferably -4.30 eV or more and -3.30 eV or less. At this time, the increase in the driving voltage of the light-emitting device can be suppressed, so it is preferred. In addition, as the substance with electron-transporting properties in the third layer 118, a phthalocyanine material or a metal complex having a metal-oxygen bond and an aromatic ligand is preferably used.

[0172] As the substance with electron-transporting properties for the third layer 118, specifically, diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviation: HATNA), 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2',3'-c]phenazine (abbreviation: HATNA-F6), 3,4,9,10-perylenetetracarboxylic diimide (abbreviation: PTCDI), 3,4,9,10-perylenetetracarboxylic acid-bis-benzimidazole (abbreviation: PTCBI) and other perylene tetracarboxylic acid derivatives, (C 60 -Ih)[5,6]fullerene (abbreviation: C 60 ), (C 70 -D5h)[5,6]fullerene (abbreviation: C 70) In addition, compounds having a heteroaromatic skeleton as a ring-fused skeleton containing a heterocycle can be used. As such a compound, for example, phthalocyanine compounds such as phthalocyanine (abbreviation: H2Pc) can be used. Further, metal phthalocyanines containing copper, zinc, cobalt, iron, chromium, nickel, etc. and their derivatives such as copper phthalocyanine (abbreviation: CuPc), zinc phthalocyanine (abbreviation: ZnPc), cobalt phthalocyanine (abbreviation: CoPc), iron phthalocyanine (abbreviation: FePc), tin phthalocyanine (abbreviation: SnPc), tin oxide phthalocyanine (abbreviation: SnOPc), titanium oxide phthalocyanine (abbreviation: TiOPc), vanadium oxide phthalocyanine (abbreviation: VOPc), etc. can be used. In particular, phthalocyanine metal complexes such as copper phthalocyanine or zinc phthalocyanine or 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2',3'-c]phenazine are preferably used.

[0173] In addition, the film thickness of the third layer 118 is preferably 1 nm or more and 10 nm or less, more preferably 2 nm or more and 5 nm or less.

[0174] In addition, since the second layer 117 in the intermediate layer 116 is used as a hole injection layer, the second light-emitting unit 502 does not have a hole injection layer, but the second light-emitting unit 502 may also have a hole injection layer.

[0175] The second electrode 102 is an electrode including a cathode. The second electrode 102 may also have a stacked structure, and in this case, the layer in contact with the organic compound layer 103 is used as the cathode. As the material for forming the cathode, metals, alloys, conductive compounds, and mixtures thereof having a small work function (specifically, 3.8 eV or less) can be used. Specific examples of such cathode materials include alkali metals such as lithium (Li) or cesium (Cs), elements belonging to Group 1 or Group 2 of the periodic table such as magnesium (Mg), calcium (Ca), or strontium (Sr), alloys containing them (MgAg, AlLi), rare earth metals such as europium (Eu) or ytterbium (Yb), and alloys containing them. Specifically, for example, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), 8-hydroxyquinoline-lithium (abbreviation: Liq), ytterbium (Yb), etc., alkali metals, alkaline earth metals, rare earth elements, their compounds or complexes, or electron compounds can be mentioned. As electron compounds, for example, substances that add electrons to a mixed oxide of calcium and aluminum at a high concentration can be mentioned. In addition, two or more of the above materials can be mixed and used. In the case where the second electrode 102 has a stacked structure, as the part other than the cathode, a material having good conductivity can be used without considering the work function.

[0176] Note that the second electron transport layer 114_2 is preferably in contact with the second electrode 102. By bringing the second electron transport layer 114_2 into contact with the second electrode 102, a light-emitting device with good electron injection and electron transport properties, low driving voltage, and low power consumption can be obtained.

[0177] In the case where the second electrode 102 is made of a material having transparency to visible light, a light-emitting device that emits light from the side of the second electrode 102 can be formed.

[0178] These conductive materials can be deposited by dry methods such as vacuum evaporation and sputtering, inkjet methods, spin coating methods, etc. In addition, they can also be formed by wet methods such as sol-gel methods or wet methods using pastes of metal materials.

[0179] In addition, as a method for forming the organic compound layer 103, various methods can be used regardless of dry or wet methods. For example, vacuum evaporation, gravure printing, offset printing, screen printing, inkjet, or spin coating methods can also be used.

[0180] In addition, the above electrodes or layers can also be formed by using different deposition methods.

[0181] Figure 2 FIG. shows two adjacent light-emitting devices (light-emitting device 130a, light-emitting device 130b) included in a display device according to one embodiment of the present invention.

[0182] The light-emitting device 130a includes an organic compound layer 103a between the first electrode 101a on the insulating layer 175 and the second electrode 102. The organic compound layer 103a has a structure in which a first light-emitting unit 501a and a second light-emitting unit 502a are stacked with an intermediate layer 116a interposed therebetween. Note that Figure 2 An example in which two light-emitting units are stacked is shown, but a structure in which three or more light-emitting units are stacked can also be adopted. The first light-emitting unit 501a includes a hole injection layer 111a, a first hole transport layer 112a_1, a first light-emitting layer 113a_1, and a first electron transport layer 114a_1 (first electron transport layer 114a_1a, first electron transport layer 114a_1b). Although the first electron transport layer 114a_1 has a stacked structure, it can also have a single-layer structure. The intermediate layer 116a includes a second layer 117a, a third layer 118a, and a first layer 119a. It does not matter whether the third layer 118a is included or not. The second light-emitting unit 502a includes a second hole transport layer 112a_2, a second light-emitting layer 113a_2, and a second electron transport layer 114a_2 (second electron transport layer 114a_2a, second electron transport layer 114a_2b).

[0183] The light-emitting device 130b includes an organic compound layer 103b between the first electrode 101b and the second electrode on the insulating layer 175. The organic compound layer 103b has a structure in which a first light-emitting unit 501b and a second light-emitting unit 502b are stacked with an intermediate layer 116b therebetween. Note that Figure 2 An example in which two light-emitting units are stacked is shown, but a structure in which three or more light-emitting units are stacked may also be employed. The first light-emitting unit 501b includes a hole injection layer 111b, a first hole transport layer 112b_1, a first light-emitting layer 113b_1, and a first electron transport layer 114b_1 (first electron transport layer 114b_1a, first electron transport layer 114b_1b). Although the first electron transport layer 114b_1 has a stacked structure, it may also have a single-layer structure. The intermediate layer 116b includes a second layer 117b, a third layer 118b, and a first layer 119b. It does not matter whether the third layer 118b is included or not. The second light-emitting unit 502b includes a second hole transport layer 112b_2, a second light-emitting layer 113b_2, and a second electron transport layer 114b_2 (second electron transport layer 114b_2a, second electron transport layer 114b_2b).

[0184] Both the second electron transport layer 114a_2 and the second electron transport layer 114b_2 have a stacked structure. Further, in the stacked structure, the layers on the cathode side, that is, the second electron transport layer 114a_2b and the second electron transport layer 114b_2b, are preferably layers having a first organic compound containing a triazine skeleton. The first layer 119a and the first layer 119b are layers having a second organic compound containing a phenanthroline skeleton.

[0185] The first light-emitting layer 113a_1 and the second light-emitting layer 113a_2 are preferably light-emitting layers that emit light of a similar color. Further, the luminescent center substances contained therein are preferably compounds having a difference in the maximum peak wavelength of the emission spectra of 30 nm or less, more preferably 20 nm or less, still more preferably 10 nm or less, and more preferably, the luminescent center substances contained therein are the same. The first light-emitting layer 113b_1 and the second light-emitting layer 113b_2 are preferably light-emitting layers that emit light of a similar color. Further, the luminescent center substances contained therein are preferably compounds having a difference in the maximum peak wavelength of the emission spectra of 30 nm or less, more preferably 20 nm or less, still more preferably 10 nm or less, and more preferably, the luminescent center substances contained therein are the same.

[0186] In addition, preferably, the first light-emitting layer 113a_1 is separated from the first light-emitting layer 113b_1, and the second light-emitting layer 113a_2 is separated from the second light-emitting layer 113b_2. In addition, preferably, the first light-emitting layer 113a_1 is different from the first light-emitting layer 113b_1, and the second light-emitting layer 113a_2 is different from the second light-emitting layer 113b_2. In addition, the emission colors of the first light-emitting layer 113a_1 and the second light-emitting layer 113a_2 are preferably different from the emission colors of the first light-emitting layer 113b_1 and the second light-emitting layer 113b_2. In addition, preferably, the light-emitting center material contained in the first light-emitting layer 113a_1 is different from the light-emitting center material contained in the first light-emitting layer 113b_1, and the light-emitting center material contained in the second light-emitting layer 113a_2 is different from the light-emitting center material contained in the second light-emitting layer 113b_2.

[0187] When the light-emitting center material contained in the first light-emitting layer 113a_1 is different from the light-emitting center material contained in the first light-emitting layer 113b_1 and the light-emitting center material contained in the second light-emitting layer 113a_2 is different from the light-emitting center material contained in the second light-emitting layer 113b_2 (for example, the following cases: the first light-emitting layer 113a_1 and the second light-emitting layer 113a_2 are blue fluorescent light-emitting layers, and the first light-emitting layer 113b_1 and the second light-emitting layer 113b_2 are green phosphorescent light-emitting layers; the first light-emitting layer 113a_1 and the second light-emitting layer 113a_2 are blue fluorescent light-emitting layers, and the first light-emitting layer 113b_1 and the second light-emitting layer 113b_2 are red phosphorescent light-emitting layers; or the first light-emitting layer 113a_1 and the second light-emitting layer 113a_2 are green phosphorescent light-emitting layers, and the first light-emitting layer 113b_1 and the second light-emitting layer 113b_2 are red phosphorescent light-emitting layers), the carrier balance of the light-emitting layers of the light-emitting devices 130a and 130b is different. Therefore, generally, in order for the light-emitting devices 130a and 130b to exhibit their respective performances, it is necessary to separately select and use appropriate intermediate layers and electron transport layers. However, by using a layer containing a first organic compound having a triazine skeleton as the second electron transport layer 114a_2 and the second electron transport layer 114b_2 and using a layer containing a second organic compound having a phenanthroline skeleton as the first layer 119a and the first layer 119b, even if the second electron transport layer 114a_2 and the second electron transport layer 114b_2 have the same structure, both the light-emitting device 130a and the light-emitting device 130b can exhibit their performances. In other words, it is possible to simultaneously achieve an improvement in productivity and an improvement in performance. In addition, the first layer 119a and the first layer 119b may also have the same structure.

[0188] In addition, the hole injection layer 111a and the hole injection layer 111b, the first hole transport layer 112a_1 and the first hole transport layer 112b_1, the first electron transport layer 114a_1 and the first electron transport layer 114b_1 (the first electron transport layer 114a_1a and the first electron transport layer 114b_1a, the first electron transport layer 114a_1b and the first electron transport layer 114b_1b), the intermediate layer 116a and the intermediate layer 116b (the second layer 117a and the second layer 117b, the third layer 118a and the third layer 118b, the first layer 119a and the first layer 119b), the second hole transport layer 112a_2 and the second hole transport layer 112b_2, and the second electron transport layer 114a_2 and the second electron transport layer 114b_2 (the second electron transport layer 114a_2a and the second electron transport layer 114b_2a, the second electron transport layer 114a_2b and the second electron transport layer 114b_2b) may be continuous layers or may be separated between the light-emitting devices 130a and 130b. By adopting continuous layers, the productivity is improved, and thus an inexpensive light-emitting device can be manufactured. By adopting layers separated between the respective light-emitting devices, materials suitable for the emission color can be used, and thus a light-emitting device or a display device having good characteristics can be manufactured. In particular, by adopting continuous layers as the second electron transport layer 114a_2b and the second electron transport layer 114b_2b, both the light-emitting device 130a and the light-emitting device 130b can be made into light-emitting devices having good characteristics, so it is preferable.

[0189] The continuous layer means that the second electron transport layer 114a_2b and the second electron transport layer 114b_2b are made of the same material. That is, by using the same material to form the second electron transport layer 114a_2b and the second electron transport layer 114b_2b, both the light-emitting device 130a and the light-emitting device 130b can be made into light-emitting devices with good characteristics. In addition, the second electron transport layer 114a_2b and the second electron transport layer 114b_2b more preferably have a similar structure, and even more preferably have the same structure. In particular, when the light-emitting center substances contained in the first light-emitting layer 113a_1 and the first light-emitting layer 113b_1 are different and the light-emitting center substances contained in the second light-emitting layer 113a_2 and the second light-emitting layer 113b_2 are different (for example, the following cases: the first light-emitting layer 113a_1 and the second light-emitting layer 113a_2 are blue fluorescent light-emitting layers, the first light-emitting layer 113b_1 and the second light-emitting layer 113b_2 are green phosphorescent light-emitting layers; the first light-emitting layer 113a_1 and the second light-emitting layer 113a_2 are blue fluorescent light-emitting layers, the first light-emitting layer 113b_1 and the second light-emitting layer 113b_2 are red phosphorescent light-emitting layers; or the first light-emitting layer 113a_1 and the second light-emitting layer 113a_2 are green phosphorescent light-emitting layers, the first light-emitting layer 113b_1 and the second light-emitting layer 113b_2 are red phosphorescent light-emitting layers), the carrier balance of the light-emitting layers of the light-emitting device 130a and the light-emitting device 130b is different. Therefore, generally, in order for the light-emitting device 130a and the light-emitting device 130b to respectively exhibit their performance, it is necessary to separately select and use appropriate intermediate layers and electron transport layers. However, by using, as the layers on the cathode side in the electron transport layer having a stacked structure, that is, the second electron transport layer 114a_2b and the second electron transport layer 114b_2b, layers containing a first organic compound having a triazine skeleton and using, as the first layer 119a and the first layer 119b, layers containing a second organic compound having a phenanthroline skeleton, even if the second electron transport layer 114a_2b and the second electron transport layer 114b_2b are continuous layers, both the light-emitting device 130a and the light-emitting device 130b can exhibit performance. In other words, it is possible to simultaneously achieve an improvement in productivity and an improvement in performance. In addition, the first layer 119a and the first layer 119b may also have the same structure.

[0190] Note that the continuous layer refers to a so-called common layer formed across both the light-emitting device 130a and the light-emitting device 130b.

[0191] Figure 3 Yes Figure 2Modification examples. Since the emission colors of the light-emitting device 130a and the light-emitting device 130b1 are different, the optical path lengths between the electrodes that can be amplified by the microcavity are different. Thus, in the light-emitting device 130b1, the distance between the electrodes can be adjusted by increasing the thickness of the light-emitting layer, such as the light-emitting layer 113b_11 and the light-emitting layer 113b_21. Alternatively, the optical path length can also be changed by increasing the thickness of the functional layer or adding functional layers, such as the hole transport layer 112b_21.

[0192] Figure 4 A diagram showing three adjacent light-emitting devices (light-emitting device 130a, light-emitting device 130b1, light-emitting device 130c) included in a display device according to one embodiment of the present invention.

[0193] The light-emitting device 130c includes an organic compound layer 103c between the first electrode 101c and the second electrode on the insulating layer 175. The organic compound layer 103c has a structure in which the first light-emitting unit 501c and the second light-emitting unit 502c are stacked with the intermediate layer 116c therebetween. Note that, although Figure 4 An example of stacking two light-emitting units is shown, but three or more light-emitting units can also be stacked. The first light-emitting unit 501c 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 (first electron transport layer 114c_1a, first electron transport layer 114c_1b). In addition, the first electron transport layer 114c_1 may also have a single-layer structure. The intermediate layer 116c includes a second layer 117c, a third layer 118c, and a first layer 119c. The presence or absence of the third layer 118c is not considered. The second light-emitting unit 502c includes a second hole transport layer 112c_2, a second light-emitting layer 113c_2, and a second electron transport layer 114c_2 (second electron transport layer 114c_2a, second electron transport layer 114c_2b).

[0194] Assume that the wavelength of the emission color of the light-emitting device 130c is shorter than that of the light-emitting device 130a and the light-emitting device 130b1. By setting the thicknesses of the first light-emitting layer 113c_1 and the second light-emitting layer 113c_2 to be thinner than the light-emitting layers of the other two light-emitting devices, the distance between the electrodes of the light-emitting device 130c is adjusted.

[0195] The second electron transport layer 114c_2 has a stacked structure. In addition, in the stacked structure, the layer on the cathode side, that is, the second electron transport layer 114c_2b, is preferably a layer containing a first organic compound having a triazine skeleton. The first layer 119c is a layer containing a second organic compound having a phenanthroline skeleton.

[0196] The first light-emitting layer 113c_1 and the second light-emitting layer 113c_2 are preferably light-emitting layers that emit light of a similar color. In addition, the light-emitting center substances they contain are preferably compounds with a difference in the maximum peak wavelength of the emission spectrum of 30 nm or less, more preferably 20 nm or less, further preferably 10 nm or less, and even more preferably, the light-emitting center substances contained are the same. In addition, preferably, the first light-emitting layer 113a_1 is separated from the first light-emitting layer 113c_1, and the second light-emitting layer 113a_2 is separated from the second light-emitting layer 113c_2. In addition, the emission colors of the first light-emitting layer 113a_1 and the second light-emitting layer 113a_2 are preferably different from the emission colors of the first light-emitting layer 113c_1 and the second light-emitting layer 113c_2. In addition, preferably, the light-emitting center substance contained in the first light-emitting layer 113a_1 is different from the light-emitting center substance contained in the first light-emitting layer 113c_1, and the light-emitting center substance contained in the second light-emitting layer 113a_2 is different from the light-emitting center substance contained in the second light-emitting layer 113c_2.

[0198] Note that the following examples are shown: the hole injection layer 111a and the hole injection layer 111c, the first hole transport layer 112a_1 and the first hole transport layer 112c_1, the first electron transport layer 114a_1 and the first electron transport layer 114c_1, the intermediate layer 116a and the intermediate layer 116c (the second layer 117a and the second layer 117c, the third layer 118a and the third layer 118c, the first layer 119a and the first layer 119c), the second hole transport layer 112a_2 and the second hole transport layer 112c_2 are layers that are independently separated from each other between the light-emitting device 130a and the light-emitting device 130c, while the second electron transport layer 114a_2 and the second electron transport layer 114c_2 are continuous layers. Thus, a light-emitting device can include both continuous layers and separated layers. Thereby, a light-emitting device or a display device with a balance between productivity and characteristics can be manufactured. In particular, the second electron transport layer 114a_2b and the second electron transport layer 114c_2b are preferably continuous layers, whereby both the light-emitting device 130a and the light-emitting device 130c can be light-emitting devices with good characteristics.

[0199] For example, in the case where there are two light-emitting devices containing a fluorescent light-emitting center substance and one light-emitting device containing a phosphorescent light-emitting center substance among the light-emitting devices of three colors, preferably, in the light-emitting device containing a fluorescent light-emitting center substance, the carrier transport layer is formed as a continuous layer, and in the light-emitting device containing a phosphorescent light-emitting center substance, the carrier transport layer is formed as a layer separated from the light-emitting devices presenting other light-emitting colors. Or, in the case where there are two light-emitting devices containing a phosphorescent light-emitting center substance and one light-emitting device containing a fluorescent light-emitting center substance among the light-emitting devices of three colors, preferably, in the light-emitting device containing a phosphorescent light-emitting center substance, the carrier transport layer is formed as a continuous layer, and in the light-emitting device containing a fluorescent light-emitting center substance, the carrier transport layer is formed as a layer separated from the light-emitting devices presenting other light-emitting colors.

[0200] The light-emitting device of the present invention having such a structure can be a light-emitting device with high current efficiency, less energy loss, and good characteristics. A display device according to one aspect of the present invention using such a light-emitting device can be a display device with low power consumption, high reliability, and good visibility capable of displaying at high brightness. In addition, this embodiment can be freely combined with other embodiments.

[0201] Embodiment 2 In this embodiment, with reference to Figure 5A and Figure 5B a display device manufactured using the light-emitting device shown in Embodiment 1 will be described. Note that Figure 5A is a top view showing the display device, and Figure 5B is a cross-sectional view taken along lines A - B and C - D in Figure 5A . This display device includes a drive circuit section (source line drive circuit) 601, a pixel section 602, and a drive circuit section (gate line drive circuit) 603, which are represented by dotted lines, as units for controlling the light emission of the light-emitting device. In addition, reference numeral 604 is a sealing substrate, reference numeral 605 is a sealing material, and the inner side surrounded by the sealing material 605 is a space 607.

[0202] Note that the guiding wiring 608 is a wiring for transmitting signals input to the source line drive circuit 601 and the gate line drive circuit 603, and receives a video signal, a clock signal, a start signal, a reset signal, etc. from an FPC (flexible printed circuit) 609 serving as an external input terminal. Note that although only the FPC is illustrated here, the FPC may also be mounted with a printed wiring board (PWB). The display device in this specification includes not only the display device main body but also a display device with an FPC or a PWB mounted thereon.

[0203] Next, with reference to Figure 5BExplain the cross-sectional structure. Although the drive circuit section and the pixel section are formed on the element substrate 610, one pixel in the source line drive circuit 601, which is the drive circuit section, and the pixel section 602 is shown here.

[0204] The element substrate 610 can use a plastic substrate made of FRP (Fiber Reinforced Plastics), PVF (polyvinyl fluoride), polyester, acrylic resin, etc., in addition to a substrate made of glass, quartz, organic resin, metal, alloy, semiconductor, etc.

[0205] There is no particular limitation on the structure of the transistors used for the pixels and the drive circuit. For example, an anti-staggered transistor or a staggered transistor can be adopted. In addition, a top-gate transistor or a bottom-gate transistor can also be adopted. There is no particular limitation on the semiconductor material used for the transistors. For example, silicon, germanium, silicon carbide, gallium nitride, etc. can be used. Or an oxide semiconductor containing at least one of indium, gallium, and zinc, such as an In-Ga-Zn-based metal oxide, can be used.

[0206] There is also no particular limitation on the crystallinity of the semiconductor material used for the transistors. An amorphous semiconductor or a semiconductor having crystallinity (microcrystalline semiconductor, polycrystalline semiconductor, single crystal 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 preferred.

[0207] Here, an oxide semiconductor is preferably used for semiconductor devices such as transistors provided in the above-mentioned pixels and drive circuits and transistors for touch sensors described later. In particular, an oxide semiconductor having a wider bandgap than silicon is preferably used. By using an oxide semiconductor having a wider bandgap than silicon, the off-state current of the transistor can be reduced.

[0208] The above-mentioned oxide semiconductor preferably contains at least indium (In) or zinc (Zn). In addition, the above-mentioned oxide semiconductor is more preferably an oxide semiconductor containing an oxide represented by In-M-Zn-based oxides (M is a metal such as Al, Ti, Ga, Ge, Y, Zr, Sn, La, Ce, or Hf).

[0209] In particular, as the semiconductor layer, an oxide semiconductor film having a plurality of crystal parts, in which the c-axis is oriented in a direction perpendicular to the formation surface of the semiconductor layer or the top surface of the semiconductor layer, and having no grain boundaries between adjacent crystal parts is preferably used.

[0210] By using the above material as the semiconductor layer, it is possible to suppress fluctuations in electrical characteristics and realize a highly reliable transistor.

[0211] In addition, since the off-state current of the transistor having the above semiconductor layer is low, the charge stored in the capacitor through the transistor can be maintained for a long period of time. By using such a transistor for a pixel, the driving circuit can be stopped while maintaining the gray scale of the image displayed in each display area. As a result, an electronic device with extremely low power consumption can be realized.

[0212] In order to stabilize the characteristics of the transistor, etc., it is preferable to provide a base film. As the base film, an inorganic insulating film such as a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a silicon nitride oxide film can be used and formed in a single layer or a stack. The base film can be formed by a sputtering method, a CVD (Chemical Vapor Deposition) method (a plasma CVD method, a thermal CVD method, a MOCVD (Metal Organic CVD) method, etc.), an ALD (Atomic Layer Deposition) method, a coating method, a printing method, etc. Note that the base film may not be provided if not necessary.

[0213] Note that FET623 shows one of the transistors formed in the driving circuit section 601. In addition, the driving circuit can also be formed using various CMOS circuits, PMOS circuits, or NMOS circuits. In addition, although in this embodiment, a driver integrated type in which the driving circuit is formed on the substrate is shown, it is not necessarily required to adopt this structure, and the driving circuit can also be formed outside the substrate instead of on the substrate.

[0214] In addition, the pixel section 602 is formed of a plurality of pixels, and each of the plurality of pixels includes a switching FET611, a current control FET612, and a first electrode 613 electrically connected to the drain of the current control FET612. However, it is not limited thereto, and a pixel section combining three or more FETs and capacitors can also be adopted.

[0215] Note that an insulator 614 is formed so as to cover the end portion of the first electrode 613. Here, a positive photosensitive acrylic resin film can be used to form the insulator 614.

[0216] In addition, the upper end portion or the lower end portion of the insulator 614 is formed into a curved surface with a curvature to obtain good coverage of an organic compound layer or the like formed later. For example, when using a positive photosensitive acrylic resin as the material of the insulator 614, it is preferable that only the upper end portion of the insulator 614 includes a curved surface having a radius of curvature (0.2 μm to 3 μm). As the insulator 614, a negative photosensitive resin or a positive photosensitive resin can be used.

[0217] An organic compound layer 616 and a second electrode 617 are formed on the first electrode 613. Here, as the material for the first electrode 613 used as an anode, a material with a large work function is preferably used. For example, in addition to single-layer films such as ITO films, indium tin oxide films containing silicon, indium oxide films containing 2 wt% to 20 wt% of zinc oxide, titanium nitride films, chromium films, tungsten films, Zn films, Pt films, etc., a stacked film composed of a titanium nitride film and a film mainly composed of aluminum and a three-layer structure composed of a titanium nitride film, a film mainly composed of aluminum, and a titanium nitride film can also be used. Note that when a stacked structure is adopted, the resistance value of the wiring can be low, good ohmic contact can be obtained, and it can be used as an anode.

[0218] In addition, the organic compound layer 616 is formed by various methods such as vapor deposition using a vapor deposition mask, inkjet method, spin coating method, etc. The organic compound layer 616 includes the structure shown in Embodiment 1. In addition, as other materials constituting the organic compound layer 616, low molecular compounds or high molecular compounds (including oligomers, dendrimers) can also be used.

[0219] In addition, as the material for the second electrode 617 formed on the organic compound layer 616 and used as a cathode, a material with a small work function (Al, Mg, Li, Ca, or their alloys and compounds (MgAg, MgIn, AlLi, etc.)) is preferably used. Note that when allowing the light generated in the organic compound layer 616 to pass through the second electrode 617, a stacked layer composed of a thin metal film and a transparent conductive film (ITO, indium oxide containing 2 wt% to 20 wt% of zinc oxide, indium tin oxide containing silicon, zinc oxide (ZnO), etc.) is preferably used as the second electrode 617.

[0220] In addition, the light-emitting device is formed by the first electrode 613, the organic compound layer 616, and the second electrode 617. This light-emitting device is the light-emitting device shown in Embodiment 1. In addition, the pixel portion is composed of a plurality of light-emitting devices, and the display device of this embodiment may also include both the light-emitting device shown in Embodiment 1 and light-emitting devices with other structures.

[0221] In addition, the sealing substrate 604 is attached to the element substrate 610 using a sealing material 605, and the light-emitting device 618 is disposed in a space 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealing material 605. Note that the space 607 is filled with a filler. As this filler, an inert gas (nitrogen, argon, etc.) can be used, and a sealing material can also be used. By forming a recess in the sealing substrate and disposing a desiccant therein, deterioration caused by the influence of moisture can be suppressed, so it is preferable.

[0222] In addition, it is preferable to use an epoxy resin and glass powder as the sealing material 605. Moreover, these materials are preferably materials that do not allow moisture and oxygen to permeate as much as possible. In addition, as the material for sealing the substrate 604, in addition to a glass substrate and a quartz substrate, a plastic substrate made of FRP (Fiber Reinforced Plastics), PVF (polyvinyl fluoride), polyester, acrylic resin, etc. can also be used.

[0223] Although not shown in Figure 5B it is also possible to provide a protective film on the second electrode 617. The protective film can be formed of an organic resin film or an inorganic insulating film. In addition, the protective film can be formed so as to cover the exposed portion of the sealing material 605. Moreover, the protective film can be provided to cover the exposed sides of the surfaces and sides of a pair of substrates, the sealing layer, the insulating layer, etc.

[0224] As the protective film, a material that does not easily allow impurities such as water to permeate can be used. Therefore, it is possible to efficiently suppress the diffusion of impurities such as water from the outside to the inside.

[0225] As the material constituting the protective film, an oxide, a nitride, a fluoride, a sulfide, a ternary compound, a metal, a polymer, etc. can be used. For example, a material containing aluminum oxide, hafnium oxide, hafnium silicate, lanthanum oxide, silicon oxide, strontium titanate, tantalum oxide, titanium oxide, zinc oxide, niobium oxide, zirconium oxide, tin oxide, yttrium oxide, cerium oxide, scandium oxide, erbium oxide, vanadium oxide, indium oxide, etc., a material containing aluminum nitride, hafnium nitride, silicon nitride, tantalum nitride, titanium nitride, niobium nitride, molybdenum nitride, zirconium nitride, gallium nitride, etc., a material containing a nitride containing titanium and aluminum, an oxide containing titanium and aluminum, an oxide containing aluminum and zinc, a sulfide containing manganese and zinc, a sulfide containing cerium and strontium, an oxide containing erbium and aluminum, an oxide containing yttrium and zirconium, etc. can be used.

[0226] The protective film is preferably formed by a deposition method with good step coverage. One such method is the ALD method. It is preferable to use a material that can be formed by the ALD method for the protective film. By the ALD method, a protective film that is dense and has reduced defects such as cracks and pinholes or has a uniform thickness can be formed. In addition, the damage to the processing members during the formation of the protective film can be reduced.

[0227] For example, by forming the protective film by the ALD method, a protective film that is uniform and has few defects can be formed on the surface having a complex uneven shape or on the top surface, side surface, and back surface of the touch panel.

[0228] As described above, a display device manufactured using the light-emitting device shown in Embodiment 1 can be obtained.

[0229] Since the light-emitting device in this embodiment uses the light-emitting element shown in Embodiment 1, a light-emitting device with excellent characteristics can be obtained. Specifically, the light-emitting element shown in Embodiment 1 has high luminous efficiency, and thus a display device with low power consumption can be realized. In addition, the light-emitting element shown in Embodiment 1 has high reliability, and thus a display device with high reliability can be realized. Also, the light-emitting element shown in Embodiment 1 can have good chromaticity and high color purity, and thus a display device with good display quality can be realized.

[0230] In addition, this embodiment can be freely combined with other embodiments.

[0231] Embodiment 3 As Figure 6A and Figure 6B shown, a plurality of light-emitting elements 130 are formed on the insulating layer 175 and constitute a display device. In this embodiment, a display device according to another aspect of the present invention will be described in detail.

[0232] The display device 100 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.

[0233] In this specification and the like, for example, when describing the common content among the sub-pixels 110R, the sub-pixel 110G, and the sub-pixel 110B, it is sometimes described as the sub-pixel 110. Similarly, when describing the common content among other components distinguished by letters, it is sometimes described using symbols with the letters omitted.

[0234] 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. In this embodiment, sub-pixels of three colors, red (R), green (G), and blue (B), are taken as an example, but a combination of sub-pixels of other colors can also be used. In addition, the number of sub-pixels is not limited to three, and four or more can also be used. As four sub-pixels, for example, sub-pixels of four colors: R, G, B, white (W); sub-pixels of four colors: R, G, B, yellow (Y); and four sub-pixels: R, G, B, infrared light (IR); etc. can be cited.

[0235] In this specification and the like, the row direction is sometimes 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.

[0236] In Figure 6AIn the example shown, 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 can also be arranged and configured in the Y direction, and sub-pixels of the same color can also be arranged and configured in the X direction.

[0237] A connection portion 140 is provided outside the pixel portion 177, and an area 141 may also be provided. In the case where the area 141 is provided, the area 141 is provided between the pixel portion 177 and the connection portion 140. In the case where the area 141 is provided, an organic compound layer is provided in the area 141. In addition, a conductive layer 151C is provided in the connection portion 140.

[0238] In Figure 6A In the example shown, the area 141 and the connection portion 140 are located on the right side of the pixel portion 177, but there is no particular limitation on the positions of the area 141 and the connection portion 140. In addition, the area 141 and the connection portion 140 may be one or more.

[0239] Figure 6B is an example of a cross-sectional view along the dotted line A1 - A2 in Figure 6A . As Figure 6B shown, the display device 100 includes an insulating layer 171, a conductive layer 172 on the insulating layer 171, an insulating layer 173 on the insulating layer 171 and on the conductive layer 172, an insulating layer 174 on the insulating layer 173, and an insulating layer 175 on the insulating layer 174. The insulating layer 171 is provided on a substrate (not shown). The insulating layer 175, the insulating layer 174, and the insulating layer 173 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.

[0240] 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. The substrate 120 is bonded to the protective layer 131 by a resin layer 122. In addition, an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 are preferably provided between adjacent light-emitting devices 130.

[0241] Figure 6B The cross-sections of a plurality of inorganic insulating layers 125 and a plurality of insulating layers 127 are shown, but when looking at the display device 100 from above, the inorganic insulating layer 125 and the insulating layer 127 are preferably formed as a connected single layer, respectively.

[0242] In Figure 6BAs the light-emitting device 130, the light-emitting devices 130R, 130G, and 130B are shown. 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. In addition, the light-emitting device 130R, 130G, or 130B can also emit other visible light or infrared light.

[0243] A display device according to one embodiment of the present invention can have, for example, a top emission structure that emits light in a direction opposite to the substrate on which the light-emitting device is formed. In addition, a display device according to one embodiment of the present invention can also have a bottom emission structure.

[0244] The light-emitting device 130R includes a first electrode 101R (pixel electrode) composed of a conductive layer 151R and a conductive layer 152R, an organic compound layer 103R on the first electrode, a common layer 104 on the organic compound layer 103R, and a second electrode (common electrode) 102 on the common layer 104. Note that the common layer 104 may not be provided, but when the common layer 104 is provided, damage to the organic compound layer 103R during processing can be reduced, so it is preferred.

[0245] The light-emitting device 130G includes a first electrode 101G (pixel electrode) composed of a conductive layer 151G and a conductive layer 152G, an organic compound layer 103G on the first electrode, a common layer 104 on the organic compound layer 103G, and a second electrode (common electrode) 102 on the common layer 104. In addition, the common layer 104 may not be provided, but when it is provided, damage to the organic compound layer 103G during processing can be reduced, so it is preferred.

[0246] The light-emitting device 130B has the structure shown in Embodiment 1. The light-emitting device 130B includes a first electrode 101B (pixel electrode) composed of a conductive layer 151B and a conductive layer 152B, an organic compound layer 103B on the first electrode, a common layer 104 on the organic compound layer 103B, and a second electrode (common electrode) 102 on the common layer 104. In addition, the common layer 104 may not be provided, but when it is provided, damage to the organic compound layer 103B during processing can be reduced, so it is preferred. In addition, when the common layer 104 is provided, the stacked structure of the organic compound layer 103B and the common layer 104 corresponds to the organic compound layer 103 in Embodiment 1, and when the common layer 104 is not provided, the organic compound layer 103B corresponds to the organic compound layer 103 in Embodiment 1.

[0247] In addition, the common layer 104 is preferably an electron transport layer. Further, in the case where the common layer 104 is an electron transport layer, the electron transport layer preferably has a stacked structure. More preferably, the layer on the second electrode side among the stacked layers is the common layer 104, and the layer on the light-emitting layer side is the organic compound layer 103.

[0248] In addition, the light-emitting devices 130R and 130G are also light-emitting devices manufactured through a photolithography process.

[0249] One of the pixel electrode and the common electrode included in the light-emitting device 130 is used as the anode, and the other is used as the cathode. Hereinafter, unless otherwise specified, the case where the pixel electrode is used as the anode and the common electrode is used as the cathode will be described.

[0250] The organic compound layers 103R, 103G, and 103B are independent in an island shape for each light-emitting device or each light-emitting 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 be suppressed even in a high-definition display device. Thereby, crosstalk can be prevented to realize a display device with extremely high contrast. In particular, a display device with high current efficiency at low brightness can be realized.

[0251] The island-shaped organic compound layer 103 is formed by depositing an organic compound film and processing the organic compound film using photolithography.

[0252] The organic compound layer 103 is preferably provided so as to cover the top surface and the side surface of the first electrode (pixel electrode) of the light-emitting device 130. Thereby, 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, it is easy to increase the aperture ratio of the display device 100. In addition, by covering the side surface of the pixel electrode of the light-emitting device 130 with the organic compound layer 103, contact between the pixel electrode and the second electrode 102 can be suppressed, and thus short circuit of the light-emitting device 130 can be suppressed.

[0253] In the display device according to one aspect of the present invention, the first electrode (pixel electrode) of the light-emitting device preferably has a stacked structure. For example, in Figure 6B the example shown, the first electrode of the light-emitting device 130 has a stacked structure of a conductive layer 151 (conductive layer 151R, conductive layer 151G, conductive layer 151B) and a conductive layer 152 (conductive layer 152R, conductive layer 152G, conductive layer 152B).

[0254] As the conductive layer 151, a metal material can be used, for example. 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.

[0255] As the conductive layer 152, an oxide containing one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used. For example, a conductive oxide including 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 is preferably used. In particular, the indium tin oxide containing silicon has a relatively large work function, for example, 4.0 eV or more, so it can be suitably used as the conductive layer 152.

[0256] The conductive layer 151 and the conductive layer 152 may each have a laminated structure including a plurality of layers containing different materials. In this case, the conductive layer 151 may 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 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 using a material that can be used for the conductive layer 152.

[0257] Next, with reference to Figures 7A to 12C An example of a manufacturing method of the display device 100 having the Figure 6A shown structure will be described.

[0258] [Example of Manufacturing Method 1] The thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device can be formed by a sputtering method, a CVD method, a vacuum evaporation method, a pulsed laser deposition (PLD) method, an ALD method, or the like.

[0259] In addition, the thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device can be formed by a wet deposition method such as a spin coating method, a dipping method, a spraying method, an inkjet method, a dispenser method, a screen printing method, an offset printing method, a doctor knife method, a slot die coating method, a roll coating method, a curtain coating method, or a knife over roll method.

[0260] In addition, when processing the thin films constituting the display device, for example, lithography can be used for processing.

[0261] In photolithography, as the light used for exposure, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these lights can be used. In addition, ultraviolet light, KrF laser, ArF laser, etc. can also be used. In addition, immersion exposure technology can also be used for exposure. In addition, as the light used for exposure, extreme ultraviolet (EUV) light or X-rays can also be used. In addition, instead of the light used for exposure, an electron beam can also be used.

[0262] In the etching of a thin film, a dry etching method, a wet etching method, a sandblasting method, etc. can be used.

[0263] 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.

[0264] As the substrate, a substrate having at least heat resistance capable of withstanding the subsequent heat treatment can be used. For example, a glass substrate; a quartz substrate; a sapphire substrate; a ceramic substrate; an organic resin substrate; or a semiconductor substrate such as a single crystal semiconductor substrate and a polycrystalline semiconductor substrate made of silicon or silicon carbide, etc., a compound semiconductor substrate such as silicon germanium, an SOI substrate, etc. can be used.

[0265] Next, as Figure 7A shown, an opening reaching the conductive layer 172 is formed in the insulating layer 175, the insulating layer 174, and the insulating layer 173. Next, a plug 176 is formed so as to fill the opening.

[0266] Next, as Figure 7A shown, a conductive film 151f that will become the conductive layer 151R, the conductive layer 151G, the conductive layer 151B, and the conductive layer 151C and a conductive film 152f that will become the conductive layer 152R, the conductive layer 152G, the conductive layer 152B, and the conductive layer 152C are formed on the plug 176 and the insulating layer 175. As the conductive film 151f, for example, a metal material can be used. As the conductive film 152f, for example, an oxide containing one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used.

[0267] Next, as Figure 7A shown, a resist mask 191 is formed on the conductive film 152f. The resist mask 191 can be formed by coating a photosensitive material (photoresist) and performing exposure and development.

[0268] Next, as Figure 7B shown, for example, the conductive films 151f and 152f in the regions that do not overlap with the resist mask 191 are removed. Thereby, the conductive layers 151 and 152 are formed.

[0269] Next, as Figure 7C shown, the resist mask 191 is removed. The resist mask 191 can be removed, for example, by ashing using oxygen plasma.

[0270] Next, as Figure 7D shown, an insulating film 156f that will later become the insulating layers 156R, 156G, 156B, and 156C is formed on the conductive layers 152R, 152G, 152B, 152C, and the insulating layer 175.

[0271] The insulating film 156f can use an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitrogen oxide insulating film. For example, silicon oxynitride can be used.

[0272] Next, as Figure 7E shown, the insulating layers 156R, 156G, 156B, and 156C are formed by processing the insulating film 156f.

[0273] Next, as Figure 8A shown, an organic compound film 103Rf is formed on the conductive layers 152R, 152G, 152B, and the insulating layer 175. In addition, as Figure 8A shown, the organic compound film 103Rf is not formed on the conductive layer 152C.

[0274] Next, as Figure 8A shown, a sacrificial film 158Rf and a mask film 159Rf are formed.

[0275] By providing the sacrificial film 158Rf on the organic compound film 103Rf, damage to the organic compound film 103Rf during the manufacturing process of the display device can be reduced, and the reliability of the light-emitting device can be improved.

[0276] As the sacrificial film 158Rf, a film with high resistance to the processing conditions of the organic compound film 103Rf is used. Specifically, a film with a large etching selectivity ratio with respect to the organic compound film 103Rf is used. As the mask film 159Rf, a film with a large etching selectivity ratio with respect to the sacrificial film 158Rf is used.

[0277] In addition, the sacrificial film 158Rf and the mask film 159Rf are formed at a temperature lower than the heat-resistant temperature of the organic compound film 103Rf. The substrate temperature during the formation of the sacrificial film 158Rf and the mask film 159Rf is typically 100°C or higher and 200°C or lower, preferably 100°C or higher and 150°C or lower, and more preferably 100°C or higher and 120°C or lower. Since the light-emitting device according to one embodiment of the present invention contains a first organic compound, a display device with high display quality can be provided even after a heating process at a higher temperature.

[0278] As the sacrificial film 158Rf and the mask film 159Rf, a film that can be removed by a wet etching method or a dry etching method is preferably used.

[0279] In addition, the sacrificial film 158Rf formed in contact with the organic compound film 103Rf is preferably formed by a formation method that causes less damage to the organic compound film 103Rf than the mask film 159Rf. For example, compared with the sputtering method, the ALD method or the vacuum evaporation method is more preferably used.

[0280] As the sacrificial film 158Rf and the mask film 159Rf, 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 can be used.

[0281] As the sacrificial film 158Rf and the mask film 159Rf, 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 these metal materials can be used respectively. In particular, low melting point materials such as aluminum or silver are preferably used. By using a metal material capable of shielding ultraviolet rays as one or both of the sacrificial film 158Rf and the mask film 159Rf, it is possible to suppress ultraviolet rays from irradiating the organic compound film 103Rf during pattern exposure and suppress the deterioration of the organic compound film 103Rf, so it is preferred.

[0282] In addition, as the sacrificial film 158Rf and the mask film 159Rf, metal oxides such as In-Ga-Zn oxide, indium oxide, In-Zn oxide, In-Sn oxide, indium-titanium oxide (In-Ti oxide), indium-tin-zinc oxide (In-Sn-Zn oxide), indium-titanium-zinc oxide (In-Ti-Zn oxide), indium-gallium-tin-zinc oxide (In-Ga-Sn-Zn oxide), indium-tin oxide containing silicon, etc. can be used respectively.

[0283] Note that an element M (M is one or more of aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) can be used in place of the above gallium in the above metal oxides.

[0284] As the sacrificial film 158Rf and the mask film 159Rf, for example, semiconductor materials such as silicon or germanium are used. This has high affinity with the semiconductor manufacturing process and is therefore preferred. In addition, compounds containing the above semiconductor materials can be used.

[0285] As the sacrificial film 158Rf and the mask film 159Rf, various inorganic insulating films can be used respectively. In particular, the adhesion of the oxide insulating film to the organic compound film 103Rf is higher than that of the nitride insulating film to the organic compound film 103Rf, so it is preferred.

[0286] Next, as Figure 8A shown, a resist mask 190R is formed. The resist mask 190R can be formed by coating a photosensitive material (photoresist) and then performing exposure and development.

[0287] The resist mask 190R is provided at a position overlapping with the conductive layer 152R. The resist mask 190R 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 display device can be suppressed.

[0288] Next, as Figure 8B shown, a part of the mask film 159Rf is removed using the resist mask 190R to form a mask layer 159R. The mask layer 159R remains on the conductive layer 152R and the conductive layer 152C. Then, the resist mask 190R is removed. Next, the mask layer 159R is used as a mask (also called a hard mask) to remove a part of the sacrificial film 158Rf to form a sacrificial layer 158R.

[0289] By using the wet etching method, compared with the case of using the dry etching method, the damage to the organic compound film 103Rf during the processing of the sacrificial film 158Rf and the mask film 159Rf can be reduced. When using the wet etching method, for example, it is preferred to use a developer, an alkaline aqueous solution such as a tetramethylammonium hydroxide (TMAH) aqueous solution, dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or an acidic aqueous solution such as a liquid medicine using a mixture of them.

[0290] In addition, when using the dry etching method during the processing of the sacrificial film 158Rf, the deterioration of the organic compound film 103Rf can be suppressed by not using an oxygen-containing gas as the etching gas.

[0291] The resist mask 190R and the resist mask 191 can be removed by the same method.

[0292] Next, as Figure 8BAs shown, the organic compound film 103Rf is processed to form the organic compound layer 103R. For example, the mask layer 159R and the sacrificial layer 158R are used as a hard mask and a part of the organic compound film 103Rf is removed, thereby forming the organic compound layer 103R.

[0293] Thus, as Figure 8B 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 conductive layer 152G and the conductive layer 152B are exposed.

[0294] The processing of the organic compound film 103Rf is preferably performed using anisotropic etching. Particularly preferably, anisotropic dry etching is used. Alternatively, wet etching may also be used.

[0295] When using the dry etching method, the deterioration of the organic compound film 103Rf can be suppressed by not using an oxygen-containing gas as the etching gas.

[0296] In addition, an oxygen-containing gas may also be used as the etching gas. When the etching gas contains oxygen, the etching rate can be increased. Therefore, etching can be performed under low-power conditions while maintaining a sufficient etching rate. Therefore, the damage to the organic compound film 103Rf can be suppressed. And, the adhesion of reaction products generated during etching and other defects can be suppressed.

[0297] When using the dry etching method, for example, it is preferable to use a gas containing one or more of H2, CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, and a noble gas such as He and Ar as the etching gas. Alternatively, it is preferable to use a gas containing one or more of the above gases and oxygen as the etching gas. Alternatively, oxygen gas may also be used as the etching gas.

[0298] Next, as Figure 9A shown, the organic compound film 103Gf that will later become the organic compound layer 103G is formed.

[0299] The organic compound film 103Gf can be formed using the same method as that applicable to the formation of the organic compound film 103Rf. In addition, the organic compound film 103Gf may have the same structure as the organic compound film 103Rf.

[0300] Next, as Figure 9A shown, the sacrificial film 158Gf and the mask film 159Gf are sequentially formed. Then, the 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 applicable to the sacrificial film 158Rf and the mask film 159Rf. The materials and formation methods of the resist mask 190G are the same as the conditions applicable to the resist mask 190R.

[0301] The resist mask 190G is disposed at a position overlapping with the conductive layer 152G.

[0302] Next, as Figure 9B 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, the mask layer 159G is used as a mask to remove a part of the sacrificial film 158Gf, thereby forming the sacrificial layer 158G. Next, the organic compound film 103Gf is processed to form the organic compound layer 103G.

[0303] Next, as Figure 9C shown, an organic compound film 103Bf is formed.

[0304] The organic compound film 103Bf can be formed using the same method as that available for the formation of the organic compound film 103Rf. In addition, the organic compound film 103Bf can have the same structure as the organic compound film 103Rf.

[0305] Next, as Figure 9C shown, the sacrificial film 158Bf and the mask film 159Bf are sequentially formed. Then, the resist mask 190B is formed. The materials and formation methods of the sacrificial film 158Bf and the mask film 159Bf are the same as the conditions available for the sacrificial film 158Rf and the mask film 159Rf. The materials and formation methods of the resist mask 190B are the same as the conditions available for the resist mask 190R.

[0306] The resist mask 190B is formed at a position overlapping with the conductive layer 152B.

[0307] Next, as Figure 9D shown, a part of the mask film 159Bf is removed using the resist mask 190B, thereby forming the mask layer 159B. The mask layer 159B remains on the conductive layer 152B. Then, the resist mask 190B is removed. Next, the mask layer 159B is used as a mask to remove a part of the sacrificial film 158Bf, thereby forming the sacrificial layer 158B. Next, 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 a hard mask to remove a part of the organic compound film 103Bf to form the organic compound layer 103B.

[0308] Thus, as Figure 9D shown, the 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 mask layer 159R and the mask layer 159G are exposed.

[0309] 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 degrees or more and 90 degrees or less.

[0310] As described above, the distance between two adjacent ones of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B formed by photolithography can be reduced to 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. Here, for example, this distance can be defined based on the distance between the opposing ends of two adjacent organic compound layers 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 display device with high clarity and a large aperture ratio can be provided. In addition, the distance between the first electrodes of adjacent light-emitting devices can be reduced, for example, to 10 μm or less, 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less. In addition, the distance between the first electrodes of adjacent light-emitting devices is preferably 2 μm or more and 5 μm or less.

[0311] Next, as Figure 10A shown, it is preferable to remove the mask layer 159R, the mask layer 159G, and the mask layer 159B.

[0312] As the mask layer removal process, the same method as the mask film processing process 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 103 during mask layer removal can be reduced.

[0313] In addition, the mask layer can also be removed by dissolving it in a polar solvent such as water or alcohol. As the alcohol, ethanol, methanol, isopropyl alcohol (IPA), or glycerol, etc. can be cited.

[0314] After removing the mask layer, a drying process can also be performed to remove the water on the surface. For example, a heat treatment can also be performed in an inert gas atmosphere or a reduced pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50°C or more and 200°C or less, preferably 60°C or more and 150°C or less, and more preferably 70°C or more and 120°C or less. By adopting a reduced pressure atmosphere, drying can be performed at a lower temperature, so it is preferable.

[0315] Next, as Figure 10B shown, an inorganic insulating film 125f is formed.

[0316] Next, as Figure 10C shown, an insulating film 127f that will become the insulating layer 127 later is formed on the inorganic insulating film 125f.

[0317] When forming the inorganic insulating film 125f and the insulating film 127f, the substrate temperature is preferably 60 °C or higher, 80 °C or higher, 100 °C or higher, or 120 °C or higher and 200 °C or lower, 180 °C or lower, 160 °C or lower, 150 °C or lower, or 140 °C or lower.

[0318] As the inorganic insulating film 125f, it is preferable to form an insulating film having a thickness of 3 nm or more, 5 nm or more, or 10 nm or more and 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less within the above substrate temperature range.

[0319] 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, for example, it is preferable to form an alumina film by the ALD method.

[0320] 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.

[0321] Next, exposure is performed to sensitize a part of the insulating film 127f with visible light or ultraviolet light. The insulating layer 127 is formed in the region between any two of the conductive layers 152R, 152G, and 152B and around the conductive layer 152C.

[0322] By means of the exposed area of 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 so that the insulating layer 127 has a portion overlapping the top surface of the conductive layer 151.

[0323] The light for exposure preferably has an i-line (wavelength 365 nm). In addition, the light for exposure may also have at least one of a g-line (wavelength 436 nm) and an h-line (wavelength 405 nm).

[0324] Next, as Figure 11A shown, development is performed to remove the exposed area in the insulating film 127f to form the insulating layer 127a.

[0325] Next, as Figure 11BAs shown, the insulating layer 127a is used as a mask for an etching process to remove a part of the inorganic insulating film 125f, thereby reducing the thickness of a part of the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B. As a result, an inorganic insulating layer 125 is formed under the insulating layer 127a. In addition, the surfaces of the portions of the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B with a small thickness are exposed. Note that hereinafter, the etching process using the insulating layer 127a as a mask is sometimes referred to as the first etching process.

[0326] 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 158R, the sacrificial layer 158G, and the sacrificial layer 158B, the first etching process can be performed at one time, which is preferable.

[0327] When performing dry etching, it is preferable to use a chlorine-based gas. As the chlorine-based gas, one gas such as Cl2, BCl3, SiCl4, and CCl4 or a gas mixture of two or more of the above can be used. In addition, one gas such as oxygen gas, hydrogen gas, helium gas, and argon gas or a gas mixture of two or more of the above can be appropriately added to the chlorine-based gas. By using dry etching, regions with a small thickness of the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B can be formed with excellent in-plane uniformity.

[0328] As a dry etching apparatus, a dry etching apparatus having a high-density plasma source can be used. As a dry etching apparatus having a high-density plasma source, for example, an inductively coupled plasma (ICP) etching apparatus can be used. Alternatively, a capacitively coupled plasma (CCP) etching apparatus including parallel plate electrodes can be used.

[0329] In addition, it is preferable to perform the first etching process using wet etching. By using the wet etching method, the damage to the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B can be reduced compared with the case of using the dry etching method. For example, an alkaline solution can be used for wet etching. For example, when wet etching an alumina film, an alkaline solution TMAH can be used. In addition, an acidic solution containing fluoride can also be used. In this case, wet etching can be performed in a coated manner. Note that when the inorganic insulating film 125f is deposited using the same material as the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B, the above etching process can be performed at one time, which is preferable.

[0330] In the first etching process, the sacrificial layers 158R, 158G, and 158B are not completely removed, and the etching process is stopped while their thicknesses are thinned. Thus, by leaving the corresponding sacrificial layers 158R, 158G, and 158B on the organic compound layers 103R, 103G, and 103B, the organic compound layers 103R, 103G, and 103B can be prevented from being damaged during the subsequent process steps.

[0331] Next, it is preferable to expose the entire substrate and irradiate the insulating layer 127a with visible light or ultraviolet light. The energy density of this exposure is preferably greater than 0 mJ / cm 2 and is 800 mJ / cm 2 Hereinafter, it is more preferably greater than 0 mJ / cm 2 and is 500 mJ / cm 2 Hereinafter. By performing such exposure after development, the transparency of the insulating layer 127a can sometimes be improved. In addition, the substrate temperature required for the heat treatment that deforms the insulating layer 127a into a tapered shape in the subsequent process steps can sometimes be reduced.

[0332] Here, by providing an oxygen barrier insulating layer (e.g., an alumina film, etc.) as the sacrificial layers 158R, 158G, and 158B, oxygen diffusion into the organic compound layers 103R, 103G, and 103B can be reduced.

[0333] 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 ([[]] Figure 11C ) having a tapered shape on its side surface. This heat treatment is performed at a temperature lower than the heat-resistant temperature of the organic compound layer. 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 an air atmosphere or an inert gas atmosphere. In addition, the heating atmosphere can be an air atmosphere or a reduced-pressure atmosphere. Thereby, 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.

[0334] In the first etching process, by not completely removing the sacrificial layers 158R, 158G, and 158B and leaving the sacrificial layers 158R, 158G, and 158B in a state where their thicknesses are thinned, the organic compound layers 103R, 103G, and 103B can be prevented from being damaged and deteriorated during this heat treatment. Thereby, the reliability of the light-emitting device can be improved.

[0335] Next, as Figure 12A shown, the insulating layer 127 is used as a mask, and an etching process is performed to remove a part of the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B. Thereby, openings are formed in each of the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B, and the top surfaces of the organic compound layer 103R, the organic compound layer 103G, the organic compound layer 103B, and the conductive layer 152C are exposed. Note that hereinafter, this etching process is sometimes referred to as the second etching process.

[0336] The end portion of the inorganic insulating layer 125 is covered by the insulating layer 127. In addition, Figure 12A an example is shown in which a part of the end portion of the sacrificial layer 158G (specifically, a conical-shaped portion formed by the first etching process) is covered by the insulating layer 127 and a conical-shaped portion formed by the second etching process is exposed.

[0337] 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 reduced compared to the case of using the dry etching method. For example, wet etching can be performed using an alkaline solution or an acidic solution. In order to prevent the organic compound layer 103 from dissolving, an aqueous solution is preferably used.

[0338] Next, as Figure 12B 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 a sputtering method or a vacuum evaporation method.

[0339] Next, as Figure 12C shown, a protective layer 131 is formed on the common electrode 155. The protective layer 131 can be formed by a method such as a vacuum evaporation method, a sputtering method, a CVD method, or an ALD method.

[0340] Next, the substrate 120 is bonded to the protective layer 131 using the resin layer 122, whereby a display device can be manufactured.

[0341] As described above, in the method of manufacturing a display device according to an aspect of the present invention, the island-shaped organic compound layer 103R, the island-shaped organic compound layer 103G, and the island-shaped 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, an island-shaped layer can be formed with a uniform thickness. Moreover, a high-definition display device or a display device with a high aperture ratio can be realized. In addition, even when the definition or aperture ratio is high and the distance between sub-pixels is extremely short, contact between the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B in adjacent sub-pixels can be suppressed. Therefore, leakage current occurring between sub-pixels can be suppressed. Thereby, crosstalk can be prevented to realize a display device with extremely high contrast. In addition, even for a display device including a tandem light-emitting device manufactured by photolithography, a display device with good characteristics can be provided.

[0342] Embodiment 4 In this embodiment, a display device according to an aspect of the present invention will be described.

[0343] The display device of this embodiment can be a high-definition display device. Therefore, for example, the display device of this embodiment can be used as a display unit of information terminal devices (wearable devices) such as watch-type and bracelet-type, and as a display unit of wearable devices that can be worn on the head, such as VR devices like head-mounted displays (HMDs) and glasses-type AR devices.

[0344] In addition, the display device of this embodiment can be a high-resolution display device or a large display device. Therefore, for example, the display device of this embodiment can be used as a display unit of the following devices: electronic devices with a relatively large screen, such as television sets, desktop or notebook personal computers, monitors for computers, digital signage, and large game machines such as pachinko machines; digital cameras; digital video cameras; digital photo frames; mobile phones; portable game machines; portable information terminals; and audio reproduction devices.

[0345] [Display Module] Figure 13A A perspective view showing the display module 280 is presented. The display module 280 includes a display device 100A and an FPC 290. Note that the display device included in the display module 280 is not limited to the display device 100A, and can be any one of the display devices 100B to 100E to be described later.

[0346] 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 the image display area in the display module 280 and is an area where light from each pixel provided in the following pixel unit 284 can be seen.

[0347] Figure 13B It is a three-dimensional schematic diagram 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.

[0348] The pixel section 284 includes a plurality of pixels 284a arranged periodically. Figure 13B An enlarged view of one pixel 284a is shown on the right side. The pixel 284a can adopt various structures described in the above embodiments.

[0349] The pixel circuit section 283 includes a plurality of pixel circuits 283a arranged periodically.

[0350] One pixel circuit 283a controls the driving of a plurality of elements included in one pixel 284a.

[0351] 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 may also have at least one of an arithmetic circuit, a storage circuit, and a power supply circuit, etc.

[0352] The FPC 290 is used as a wiring for supplying a video signal, a power potential, etc. from the outside to the circuit section 282. In addition, an IC may be mounted on the FPC 290.

[0353] The display module 280 can adopt a structure in which one or both of the pixel circuit section 283 and the circuit section 282 are stacked on the lower side of the pixel section 284, so the display section 281 can have an extremely high aperture ratio (effective display area ratio).

[0354] The above display module 280 has extremely high clarity, so it can be suitably used for VR devices such as HMDs or glasses-type AR devices. For example, in the structure of viewing the display section of the display module 280 through a lens, because the display module 280 has a display section 281 with extremely high clarity, even if the user magnifies the display section with the lens, pixels cannot be seen, and thus a display with a high sense of immersion can be achieved. In addition, the display module 280 is not limited to this and can also be applied to electronic devices with a relatively small display section.

[0355] [Display Device 100A] Figure 14AThe display device 100A shown 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.

[0356] The substrate 301 corresponds to Figure 14A and Figure 14B 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 crystal 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.

[0357] In addition, an element isolation layer 315 is provided in a manner of being embedded in the substrate 301 between two adjacent transistors 310.

[0358] In addition, an insulating layer 261 is provided to cover the transistor 310, and a capacitor 240 is provided on the insulating layer 261.

[0359] The capacitor 240 includes a conductive layer 241, a conductive layer 245, and an insulating layer 243 located between them. The conductive layer 241 is used as one electrode in the capacitor 240, the conductive layer 245 is used as the other electrode in the capacitor 240, and the insulating layer 243 is used as the dielectric of the capacitor 240.

[0360] The conductive layer 241 is provided on the insulating layer 261 and is embedded in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source and the drain of the transistor 310 through a plug 271 embedded in the insulating layer 261. The insulating layer 243 is provided to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping the conductive layer 241 with the insulating layer 243 therebetween.

[0361] An insulating layer 255 is provided to cover the capacitor 240. An insulating layer 174 is provided on the insulating layer 255, and an insulating layer 175 is provided on the insulating layer 174. Light-emitting devices 130R, 130G, and 130B are provided on the insulating layer 175. An insulator is provided in a region between adjacent light-emitting devices.

[0362] The insulating layer 156R is provided in such a manner as to include a region overlapping with the side surface of the conductive layer 151R, the insulating layer 156G is provided in such a manner as to include a region overlapping with the side surface of the conductive layer 151G, and the insulating layer 156B is provided in such a manner as to include a region overlapping with the side surface of the conductive layer 151B. In addition, the conductive layer 152R is provided so as to cover the conductive layer 151R and the insulating layer 156R, the conductive layer 152G is provided so as to cover the conductive layer 151G and the insulating layer 156G, and the conductive layer 152B is provided so as to cover the conductive layer 151B and the insulating layer 156B. The sacrificial layer 158R is located on the organic compound layer 103R, the sacrificial layer 158G is located on the organic compound layer 103G, and the sacrificial layer 158B is located on the organic compound layer 103B.

[0363] 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. Various conductive materials can be used for the plug.

[0364] 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 device 130 to the substrate 120 can be referred to in Embodiment 3. The substrate 120 corresponds to Figure 13A the substrate 292.

[0365] Figure 14B Shows Figure 14A a modified example of the display device 100A shown. Figure 14B The display device shown includes a coloring layer 132R, a coloring layer 132G, and a coloring layer 132B, and the light-emitting device 130 has a region overlapping with one of the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B. In Figure 14B the display device shown, 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.

[0366] [Display device 100B] Figure 15 Shows a perspective view of the display device 100B, Figure 16 shows a cross-sectional view of the display device 100C.

[0367] The display device 100B has a structure in which the substrate 352 is bonded to the substrate 351. In Figure 15 it, the substrate 352 is indicated by a dashed line.

[0368] The display device 100B includes a pixel section 177, a connection section 140, a circuit 356, a wiring 355, etc. Figure 15 An example is shown in which the display device 100B is mounted with an IC 354 and an FPC 353. Therefore, Figure 15 the structure shown can also be referred to as a display module including the display device 100B, an IC (integrated circuit), and an FPC. Here, the substrate of the display 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.

[0369] The connection section 140 is provided outside the pixel section 177. The connection section 140 can be one or more. In the connection section 140, the common electrode of the light-emitting device is electrically connected to the conductive layer, and a potential can be supplied to the common electrode.

[0370] As the circuit 356, for example, a scan line driving circuit can be used.

[0371] The wiring 355 has a function of supplying signals and power to the pixel section 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.

[0372] Figure 15 An example is shown in which the IC 354 is provided on the substrate 351 by a method such as COG (Chip On Glass) or COF (Chip On Film). As the IC 354, for example, an IC including a scan line driving circuit or a signal line driving circuit, etc. can be used. Note that the display 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 the COF method.

[0373] Figure 16 As the display device 100C, Figure 15 an example of a cross-section of a part of the area including the FPC 353, a part of the circuit 356, a part of the pixel section 177, a part of the connection section 140, and a part of the area including the end portion of the display device 100B shown in

[0374] [Display device 100C] Figure 16 The display device 100C shown 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.

[0375] Details of the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B can be referred to in Embodiment 3.

[0376] 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.

[0377] 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. The insulating layer 156R is provided in a manner including a region in contact with the side surface of the conductive layer 151R, and the conductive layer 152R is provided to cover the conductive layer 151R and the insulating layer 156R.

[0378] 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 the detailed description is omitted.

[0379] 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 recesses are filled with the layer 128.

[0380] The layer 128 has a function of flattening the recesses of the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B. The conductive layer 151R, the conductive layer 151G, and the conductive layer 151B electrically connected to the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B are provided on the conductive layer 224R, the conductive layer 224G, the conductive layer 224B, and the layer 128. Therefore, the region overlapping with the recesses of the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B can also be used as a light-emitting region, and the aperture ratio of the pixel can be improved.

[0381] The layer 128 can also be an insulating layer or a conductive layer. The layer 128 can appropriately use various inorganic insulating materials, organic insulating materials, and conductive materials. In particular, the layer 128 is preferably formed of an insulating material, and more preferably formed of an organic insulating material. For example, the layer 128 can use the organic insulating material that can be used for the insulating layer 127 described above.

[0382] A protective layer 131 is provided on the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 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 with a solid-sealing structure, a hollow-sealing structure, or the like. In Figure 16 , the space between the substrate 352 and the substrate 351 is filled with the adhesive layer 142, that is, a solid-sealing structure is adopted. Alternatively, an inert gas (such as nitrogen or argon) can also be used to fill the space, that is, a hollow-sealing structure is adopted. 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, the space can also be filled with a resin different from the adhesive layer 142 provided in a frame shape.

[0383] Figure 16 The following example is shown: The connection portion 140 includes a conductive layer 224C obtained by processing a conductive film identical to the conductive layers 224R, 224G, and 224B, a conductive layer 151C obtained by processing a conductive film identical to the conductive layers 151R, 151G, and 151B, and a conductive layer 152C obtained by processing a conductive film identical to the conductive layers 152R, 152G, and 152B. In addition, Figure 16 An example is shown in which the insulating layer 156C is provided in a manner that includes a region overlapping with the side surface of the conductive layer 151C.

[0384] The display device 100C is a top-emission structure display device. The light-emitting device emits light to the side of the substrate 352. The substrate 352 is preferably made of a material with high visible light transmittance. The pixel electrode includes a material that reflects visible light, and the counter electrode (common electrode 155) includes a material that transmits visible light.

[0385] 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 is used as the gate insulating layer of each transistor. A part of the insulating layer 213 is used as the gate insulating layer of each transistor. The insulating layer 215 is provided to cover the transistors. The insulating layer 214 is provided to cover the transistors 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 it can be one or two or more.

[0386] Preferably, an inorganic insulating film is used as the insulating layer 211, the insulating layer 213, and the insulating layer 215.

[0387] Preferably, an organic insulating layer is used as the insulating layer 214 serving as the planarization layer.

[0388] 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.

[0389] 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, a source electrode or a drain electrode of the transistor 201 is electrically connected to the FPC 353 through the conductive layer 166 and the connection layer 242. The following example is shown: the conductive layer 166 has a stacked structure of a 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.

[0390] 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.

[0391] Each of the substrate 351 and the substrate 352 can be made of a material that can be used for the substrate 120.

[0392] As the adhesive layer 142, a material that can be used for the resin layer 122 can be used.

[0393] As the connection layer 242, an anisotropic conductive film (ACF: Anisotropic Conductive Film), an anisotropic conductive paste (ACP: Anisotropic Conductive Paste), or the like can be used.

[0394] [Display device 100D] Figure 17 The shown display device 100D and Figure 16 The main difference between the shown display device 100D and the shown display device 100C is that the display device 100D is a bottom-emission structure display device.

[0395] The light-emitting device emits light to the side of the substrate 351. The substrate 351 is preferably made of a material having high transmittance to visible light. On the other hand, there is no limitation on the light transmittance of the material used for the substrate 352.

[0396] Preferably, a light-shielding layer 317 is formed between the substrate 351 and the transistor 201 and between the substrate 351 and the transistor 205. Figure 17 An example is shown in which a light-shielding layer 317 is provided on the substrate 351, an insulating layer 153 is provided on the light-shielding layer 317, and transistors 201, 205, etc. are provided on the insulating layer 153.

[0397] 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.

[0398] 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.

[0399] The conductive layers 112R, 112B, 126R, 126B, 129R, and 129B all use materials having high transmittance to visible light. As the second electrode 102, a material that reflects visible light is preferably used.

[0400] Note that although Figure 17 the light-emitting device 130G is not shown in

[0401] In addition, Figure 17 examples such as

[0402] [Display device 100D2] Figure 18A The shown display device 100D2 is an example of a display device having a bottom emission structure different from that of Figure 17 the shown display device 100D. The difference between the display device 100D2 and the display device 100D is that the former includes an organic resin layer 180. Note that in the drawings, the symbols of the same components as those in Figure 17 may sometimes be omitted, and the detailed content can be referred to Figure 17 for the description.

[0403] In addition, Figure 18B an example of the top surface layout of the pixel 178 (pixel 178a and pixel 178b) including the sub-pixels 110 (sub-pixel 110R, sub-pixel 110G, sub-pixel 110B, sub-pixel 110W) is shown, Figure 18C a top view of the organic resin layer 180 in the region where the sub-pixels 110R and 110G included in the pixel 178 are formed is shown. In addition, the width 110Rw in the light-emitting region of the sub-pixel 110R is between the light-shielding layers 317.

[0404] As shown in Figure 18AAs shown, an organic resin layer 180 is provided on an insulating layer 214. As Figure 18A in the region surrounded by a dotted line in Figure 18C shown, the organic resin layer 180 includes concave portions 181 (concave portion 181a, concave portion 181b) having a curved surface at least in the region where sub-pixels are formed. In addition, the concave portion 181 may be provided outside the light-emitting region like the concave portion 181c. By providing the concave portion 181c, light generated in the region overlapping with the light-shielding layer 317 or light entering the region overlapping with the light-shielding layer 317 is refracted, and it can be extracted from the light-emitting region, thereby improving the light-emitting efficiency.

[0405] The plurality of concave portions 181 may also be formed in a matrix shape. The concave portion 181a and the concave portion 181b may be provided in contact with each other or may be provided with a flat surface therebetween.

[0406] In addition, although Figures 18A to 18C shows a case where the top surface shape of the concave portion is hexagonal ( Figure 18C ) and the cross-sectional shape is semi-circular ( Figure 18A ), other shapes may be adopted as needed. For example, as the top surface shape of the concave portion, polygons such as triangles, quadrilaterals (including rectangles, squares), pentagons, etc., shapes in which the corners of the above polygons are rounded, ellipses or circles, etc. can be cited.

[0407] As the organic resin layer 180, an insulating layer containing an organic material can be used. For example, as the organic resin layer 180, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimide amide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenolic resin, and precursors of the above resins, etc. can be used. In addition, as the organic resin layer 180, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinyl pyrrolidone, polyethylene glycol, polyglycerol, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin can also be used.

[0408] In addition, as the organic resin layer 180, a photosensitive resin can be used. As the photosensitive resin, a photoresist can also be used. The photosensitive resin can use a positive-type material or a negative-type material.

[0409] The organic resin layer 180 may also contain a material that absorbs visible light. For example, the organic resin layer 180 itself may be composed of a material that absorbs visible light, and the organic resin layer 180 may also contain a pigment that absorbs visible light. As the organic resin layer 180, for example, the following resins can be used: resins that can be used as color filters that transmit red light, blue light, or green light and absorb light of other colors; or resins that contain carbon black as a pigment and are used as black matrices; etc.

[0410] In addition, a first electrode 101 (first electrodes 101R and 101W) is provided on the organic resin layer 180, and an organic compound layer 103 is provided on the first electrode 101. The ends of the first electrode 101 and the organic compound layer 103 may also be covered by an insulating layer 127.

[0411] In addition, the first electrode 101 formed on the organic resin layer 180 has a recess in the same manner as the recess of the organic resin layer 180. The organic compound layer 103 formed on the first electrode 101 has a recess in the same manner as the recess of the first electrode 101. The common layer 104 formed on the organic compound layer 103 has a recess in the same manner as the recess of the organic compound layer 103. Further, the second electrode 102 formed on the common layer 104 has a recess in the same manner as the recess of the common layer 104. In other words, the recesses of the organic resin layer 180, the first electrode 101, the organic compound layer 103, the common layer 104, and the second electrode 102 overlap each other.

[0412] In addition, a common layer 104 is provided on the organic compound layer 103 and the insulating layer 127, and a second electrode 102 is provided on the common layer 104. A protective layer 131 is provided on the second electrode 102 and is bonded to the substrate 352 with an adhesive layer 142 interposed therebetween.

[0413] Note that, although Figures 18A to 18C the light-emitting devices 130G and 130B are not shown, the light-emitting devices 130G and 130B are provided.

[0414] [Display device 100E] Figure 19 The display device 100E shown is Figure 16 a modified example of the display device 100C shown, and the main difference between the display device 100E and the display device 100C is that the former includes a coloring layer 132R, a coloring layer 132G, and a coloring layer 132B.

[0415] In the display device 100E, the light-emitting device 130 has a region 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 may be provided on the surface of the substrate 352 on the side of the substrate 351. The ends of the coloring layer 132R, the ends of the coloring layer 132G, and the ends of the coloring layer 132B may overlap the light-shielding layer 157.

[0416] In the display device 100E, the light-emitting device 130 can emit white light, for example. In addition, for example, the color filter layer 132R, the color filter layer 132G, and the color filter layer 132B can transmit red light, green light, and blue light, respectively. In addition, the display device 100E can also adopt a structure in which the color filter layer 132R, the color filter layer 132G, and the color filter layer 132B are provided between the protective layer 131 and the adhesive layer 142.

[0417] [Display device 100E2] Figure 20A The shown display device 100E2 is Figure 19 a modified example of the shown display device 100E, which includes microlenses 182 on the color filter layer 132R, the color filter layer 132G, and the color filter layer 132B. Note that in the drawings, the symbols of the same components as those in Figure 19 may sometimes be omitted, and the detailed content can be referred to Figure 19 the description of

[0418] In addition, Figure 20B the top surface layout of the pixel 178 (pixel 178a and pixel 178b) including the sub-pixels 110 (sub-pixel 110R, sub-pixel 110G, sub-pixel 110B) is shown, Figure 20C and the top view of the microlenses 182 in the region where the sub-pixels 110R and sub-pixel 110G included in the pixel 178 are formed is shown. Note that the region where the common electrode 155 contacts the organic compound layer 103 is the width 110Gw in the light-emitting region of the sub-pixel 110G.

[0419] In Figure 20A the shown display device 100E2, a planarization film 143 is provided on the protective layer 131, and the color filter layer 132R, the color filter layer 132G, and the color filter layer 132B are provided on the planarization film 143. The planarization film 144 is provided so as to cover the color filter layer 132R, the color filter layer 132G, and the color filter layer 132B. The microlenses 182 are provided on the planarization film 144.

[0420] In addition, as Figure 20C shown, it is preferable to provide the microlenses 182 for each sub-pixel in the region where the sub-pixels are formed.

[0421] Note that in Figure 20C the top surface shape of the microlens 182 is hexagonal, but other shapes can be adopted as needed. For example, as the top surface shape of the microlens 182, polygons such as triangles, quadrilaterals (including rectangles and squares), pentagons, etc., shapes in which the corners of the above polygons are rounded, ellipses, or circles can be cited.

[0422] The microlenses 182 can be formed using the same material as the organic resin layer 180.

[0423] 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.

[0424] Embodiment 5 In this embodiment, an electronic device according to one aspect of the present invention will be described.

[0425] The electronic device of this embodiment includes a display device according to one aspect of the present invention in the display unit. The display device according to one aspect of the present invention has low power consumption and high reliability. Therefore, it can be used in the display units of various electronic devices.

[0426] Examples of electronic devices include, in addition to electronic devices with relatively large screens such as television sets, desktop or notebook personal computers, monitors for computers, digital signage, and large gaming machines such as pachinko machines, digital cameras, digital video cameras, digital photo frames, mobile phones, portable gaming machines, portable information terminals, and sound reproduction devices.

[0427] Refer to Figures 21A to 21D An example of a wearable device that can be worn on the head will be described.

[0428] Figure 21A The illustrated electronic device 700A and Figure 21B The illustrated electronic device 700B both include 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.

[0429] The display panel 751 can apply the display device according to one aspect of the present invention. Thereby, a highly reliable electronic device can be realized.

[0430] 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 light transmissivity, the user can see the image displayed in the display area overlapping with the transmitted image seen through the optical member 753.

[0431] 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 in the electronic device 700A and the electronic device 700B, the orientation of the user's head can be detected and the image corresponding to that direction can be displayed on the display area 756.

[0432] The communication unit has a wireless communication device, through which an image signal can be supplied, 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 may be included.

[0433] In addition, the electronic device 700A and the electronic device 700B are provided with a battery and can be charged in one or both of a wireless manner and a wired manner.

[0434] The housing 721 may also be provided with a touch sensor module.

[0435] As the touch sensor module, various touch sensors can be used. For example, various methods such as a capacitive method, a resistive film method, an infrared method, an electromagnetic induction method, a surface acoustic wave method, or an optical method can be adopted. In particular, it is preferable to apply a capacitive method or an optical method sensor to the touch sensor module.

[0436] Figure 21C The illustrated electronic device 800A and Figure 21D the illustrated electronic device 800B 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.

[0437] The display unit 820 can apply the display device of one aspect of the present invention. Thereby, a highly reliable electronic device can be realized.

[0438] The display unit 820 is disposed 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.

[0439] 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.

[0440] The user can wear the electronic device 800A or the electronic device 800B on the head using the mounting unit 823.

[0441] 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, a plurality of cameras may be provided to be able to correspond to various perspectives such as telephoto and wide-angle.

[0442] The electronic device 800A may also include a vibration mechanism that serves as a bone conduction earphone.

[0443] The electronic device 800A and the electronic device 800B may also both include input terminals. A cable for supplying an image signal from an image output device or the like and power for charging a battery provided in the electronic device may be connected to the input terminals.

[0444] The electronic device according to one embodiment of the present invention may also have a function of wirelessly communicating with the earphone 750.

[0445] In addition, the electronic device may also include an earphone unit. Figure 21B The illustrated electronic device 700B includes an earphone unit 727. A part of the wiring connecting the earphone unit 727 and the control unit may also be arranged inside the housing 721 or the mounting portion 723.

[0446] Similarly, Figure 21D The illustrated electronic device 800B includes an earphone unit 827. For example, a structure in which the earphone unit 827 and the control unit 824 are connected in a wired manner may be adopted.

[0447] Thus, as the electronic device according to one embodiment of the present invention, both the glasses type (such as the electronic devices 700A and 700B) and the goggles type (such as the electronic devices 800A and 800B) are preferable.

[0448] Figure 22A The illustrated electronic device 6500 is a portable information terminal device that can be used as a smartphone.

[0449] The electronic device 6500 includes a housing 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, a light source 6508, etc. The display unit 6502 has a touch panel function.

[0450] The display unit 6502 may use the display device according to one embodiment of the present invention. Thereby, a highly reliable electronic device can be realized.

[0451] Figure 22B It is a schematic cross-sectional view of an end portion on the microphone 6506 side including the housing 6501.

[0452] A protective member 6510 having translucency is provided on the display surface side of the housing 6501, and a display panel 6511, an optical member 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc. are provided in a space surrounded by the housing 6501 and the protective member 6510.

[0453] The display panel 6511, the optical member 6512, and the touch sensor panel 6513 are fixed to the protective member 6510 using an adhesive layer (not shown).

[0454] In a region outside the display unit 6502, a part of the display panel 6511 is folded, and an FPC 6515 is connected to the folded part. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on a printed circuit board 6517.

[0455] The display panel 6511 can use a display device according to one aspect of the present invention. Thereby, an extremely lightweight electronic device can be realized. Further, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be mounted while suppressing the thickness of the electronic device. Further, by folding a part of the display panel 6511 to provide a connection portion with the FPC 6515 on the back surface of the pixel portion, a narrow-bezel electronic device can be realized.

[0456] Figure 22C An example of a television device is shown. In the television device 7100, a display unit 7000 is assembled in a housing 7171. A structure in which the housing 7171 is supported by a bracket 7173 is shown here.

[0457] The display unit 7000 can use a display device according to one aspect of the present invention. Thereby, a highly reliable electronic device can be realized.

[0458] The operation of the television device 7100 shown can be performed by using operation switches provided in the housing 7171 and a separately provided remote controller 7151. Figure 22C The operation of the television device 7100 shown is performed.

[0459] Figure 22D An example of a notebook personal computer is shown. The notebook personal computer 7200 includes a housing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, and the like. A display unit 7000 is assembled in the housing 7211.

[0460] The display unit 7000 can use a display device according to one aspect of the present invention. Thereby, a highly reliable electronic device can be realized.

[0461] Figure 22E and Figure 22F An example of a digital signage is shown.

[0462] Figure 22E The digital signage 7300 shown includes a housing 7301, a display unit 7000, a speaker 7303, and the like. Further, it may include an LED lamp, operation keys (including a power switch or operation switches), connection terminals, various sensors, a microphone, and the like.

[0463] Figure 22FA digital sign 7400 provided on a cylindrical column 7401 is shown. The digital sign 7400 includes a display unit 7000 provided along the curved surface of the column 7401.

[0464] In Figure 22E and Figure 22F the display device of one embodiment of the present invention can be used for the display unit 7000. Thus, a highly reliable electronic device can be realized.

[0465] The larger the display unit 7000 is, the more information can be provided at one time. The larger the display unit 7000 is, the more likely it is to attract people's attention. For example, the advertising effect can be improved.

[0466] As Figure 22E and Figure 22F shown, the digital sign 7300 or the digital sign 7400 can preferably be linked with an information terminal device 7311 such as a smart phone carried by a user or an information terminal device 7411 through wireless communication.

[0467] Figures 23A to 23G The electronic device shown includes a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), connection terminals 9006, a sensor 9007 (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, power, radiation, flow rate, humidity, inclination, vibration, odor or infrared rays), a microphone 9008, etc.

[0468] Figures 23A to 23G The electronic device shown has 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, a date or a time, etc.; a function of controlling and processing through the use of various software (programs); a function of performing wireless communication; a function of reading out programs or data stored in a storage medium and processing them; etc.

[0469] Next, the electronic device shown Figures 23A to 23G will be described in detail.

[0470] Figure 23A is a perspective view showing a portable information terminal 9171. The portable information terminal 9171 can be used as a smart phone, for example. Note that in the portable information terminal 9171, a speaker 9003, connection terminals 9006 or a sensor 9007, etc. can also be provided. In addition, as the portable information terminal 9171, text or image information can be displayed on its multiple surfaces. In Figure 23AAn example of displaying three icons 9050 is shown. In addition, information 9051 shown as a rectangle with a dashed line can be displayed on other surfaces of the display unit 9001. As an example of the information 9051, information indicating receipt of an email, SNS, phone call, etc.; the title of an email or SNS, etc.; the sender's name of an email or SNS, etc.; the date; the time; the battery level; and the radio wave intensity, etc. can be cited. Alternatively, an icon 9050, etc. can be displayed at the position where the information 9051 is displayed.

[0471] Figure 23B is a perspective view showing a portable information terminal 9172. The portable information terminal 9172 has a function of displaying information on three or more surfaces of the display unit 9001. Here, an example in which information 9052, information 9053, and information 9054 are respectively displayed on different surfaces is shown. For example, in a state where the portable information terminal 9172 is placed in an upper pocket, the user can confirm the information 9053 displayed at a position seen from above the portable information terminal 9172.

[0472] Figure 23C is a perspective view showing a tablet terminal 9173. The tablet terminal 9173 can execute various application software such as a mobile phone, reading and editing of emails and articles, playing music, network communication, computer games, etc. The tablet terminal 9173 includes a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front surface of the housing 9000, and includes operation keys 9005 used as operation buttons on the left side surface of the housing 9000 and connection terminals 9006 on the bottom surface.

[0473] Figure 23D is a perspective view showing a watch-type portable information terminal 9200. The portable information terminal 9200 can be used as, for example, a smart watch (registered trademark). In addition, the display surface of the display unit 9001 is curved, and display can be performed along the curved display surface. In addition, the portable information terminal 9200 can perform a hands-free call, for example, by communicating with a headset capable of wireless communication. In addition, by using the connection terminal 9006, the portable information terminal 9200 can perform data transmission with other information terminals or be charged. Charging can also be performed by wireless power supply.

[0474] Figures 23E to 23G is a perspective view showing a foldable portable information terminal 9201. In addition, Figure 23E is a perspective view of the state where the portable information terminal 9201 is unfolded, Figure 23G is a perspective view of the folded state, Figure 23F is from Figure 23E the state of Figure 23GA perspective view of an intermediate state when converting from one of the states to another. The portable information terminal 9201 has good portability in the folded state, and has strong display readability in the unfolded state because it has a large display area with seamless splicing. The display unit 9001 included in the portable information terminal 9201 is supported by three frames 9000 connected by a hinge 9055. The display unit 9001 can be bent, for example, in a range where the radius of curvature is 0.1 mm or more and 150 mm or less.

[0475] 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, the structural examples can be appropriately combined. Example 1

[0476] In this example, the detailed manufacturing methods and characteristics of the light-emitting devices R1, G1, and B1, which are light-emitting devices according to one aspect of the present invention, and the comparative light-emitting devices R1, G1, and B1, which are comparative light-emitting devices, are described. The structural formulas of the main compounds used in this example are shown below.

[0477] [Chemical formula 7]

[0478] [Chemical formula 8]

[0479] (Manufacturing method of the light-emitting device R1) First, silver (Ag) with a thickness of 100 nm as a reflective electrode and indium tin oxide (ITSO) containing silicon oxide with a thickness of 85 nm as a transparent electrode are sequentially laminated from the substrate side on a glass substrate by sputtering to form a first electrode 101 with a size of 2 mm × 2 mm. Note that the transparent electrode is used as an anode and is regarded as the first electrode 101 in combination with the above reflective electrode.

[0480] Next, as a pretreatment for forming a light-emitting device on the substrate, the surface of the substrate is washed with water and baked at 200 °C for 1 hour.

[0481] Then, the substrate is placed in a vacuum evaporation apparatus whose internal pressure is reduced to about 1 × 10 -4 Pa, and in the heating chamber in the vacuum evaporation apparatus, vacuum baking is performed at 170 °C for 30 minutes, and then the substrate is cooled for about 30 minutes.

[0482] Next, the substrate is fixed to the substrate holder in the vacuum evaporation equipment such that the surface on which the first electrode 101 is formed is positioned downward. On the first electrode 101, N-(biphenyl-2-yl)-N-(9,9-dimethylfluoren-2-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: oFBiSF(2)) represented by the above structural formula (i) and an electron acceptor material (OCHD-003) having a molecular weight of 672 and containing fluorine are co-evaporated by evaporation method to a thickness of 10 nm such that their weight ratio is 1:0.03 (= oFBiSF(2):OCHD-003), thereby forming a hole injection layer 111.

[0483] On the hole injection layer 111, oFBiSF(2) is evaporated to a thickness of 150 nm, thereby forming a first hole transport layer.

[0484] Next, 11-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]phenanthro[9',10':4,5]furo[2,3-b]pyrazine (abbreviation: 11mDBtBPPnfpr) represented by the above structural formula (ii), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviation: PCBBiF), and a red phosphorescent material OCPG-006 are co-evaporated to a thickness of 40 nm on the first hole transport layer such that their weight ratio is 0.7:0.3:0.05 (= 11mDBtBPPnfpr:PCBBiF:OCPG-006), thereby forming a first light-emitting layer.

[0485] Then, 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02) represented by the above structural formula (iv) is evaporated to a thickness of 10 nm, thereby forming a first electron transport layer.

[0486] After forming the first electron transport layer, an intermediate layer is formed through the following steps: co-evaporating 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P) represented by the above structural formula (v) and lithium oxide (Li2O) as a second organic compound containing a phenanthroline skeleton with a thickness of 5 nm such that their weight ratio is 1:0.02 (= mPPhen2P:Li2O), thereby forming the first layer; evaporating copper phthalocyanine (abbreviation: CuPc) represented by the above structural formula (vii) with a thickness of 2 nm, thereby forming the third layer; and co-evaporating oFBiSF(2) and OCHD-003 with a thickness of 10 nm such that their weight ratio is 1:0.15 (= oFBiSF(2):OCHD-003), thereby forming the second layer.

[0487] On the intermediate layer, oFBiSF(2) is evaporated with a thickness of 65 nm, thereby forming the second hole transport layer.

[0488] On the second hole transport layer, 11mDBtBPPnfpr, PCBBiF, and OCPG-006 are co-evaporated with a thickness of 40 nm such that their weight ratio is 0.7:0.3:0.05 (= 11mDBtBPPnfpr:PCBBiF:OCPG-006), thereby forming the second light-emitting layer.

[0489] Then, 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)-biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn) represented by the above structural formula (viii) is deposited with a thickness of 10 nm, and then 2,2'-[1,2-naphthalenediylbis(4,1-phenylene)]bis(4,6-diphenyl-1,3,5-triazine) (abbreviation: TznP2N) represented by the above structural formula (ix) and lithium 8-hydroxyquinolate (abbreviation: Liq) represented by the above structural formula (x) are co-evaporated with a thickness of 25 nm such that their weight ratio is 1:1 (= TznP2N:Liq), thereby forming the second electron transport layer.

[0490] Then, Liq is evaporated with a thickness of 1 nm, and silver (Ag) and magnesium (Mg) are co-evaporated with a thickness of 15 nm such that their volume ratio is 1:0.1, thereby forming the second electrode 102. In addition, on the second electrode 102, 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzothiophene) (abbreviation: DBT3P-II) represented by the above structural formula (xi) is deposited with a thickness of 70 nm as a capping layer, thereby improving the light extraction efficiency.

[0491] Next, in a glove box filled with nitrogen atmosphere, a sealing process is carried out using a glass substrate in such a way that the light-emitting device is not exposed to the atmosphere (a UV-curable sealing material is coated around the device, and UV is irradiated only on the sealing material without irradiating the light-emitting device, and heat treatment is carried out at 80 °C for 1 hour under atmospheric pressure), thereby forming the light-emitting device R1.

[0492] (Manufacturing method of comparative light-emitting device R1) The difference between the comparative light-emitting device R1 and the manufacturing method of the light-emitting device R1 is that: the comparative light-emitting device R1 forms the second hole transport layer with a thickness of 75 nm, and co-evaporation is carried out in such a way that the weight ratio of 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm) represented by the above structural formula (xii) to Liq is 1:1 (= 6BP-4Cz2PPm:Liq) and the thickness is 25 nm to form the second electron transport layer.

[0493] (Manufacturing method of light-emitting device G1) The difference between the manufacturing method of the light-emitting device G1 and the manufacturing method of the light-emitting device R1 is that: the light-emitting device G1 forms the first hole transport layer with a thickness of 80 nm, forms the second hole transport layer with a thickness of 50 nm, and co-evaporation is carried out in such a way that the weight ratio of 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA) represented by the above structural formula (xii) to 9,10-diphenyl-2-[N-phenyl-N-(9-phenyl-carbazol-3-yl)-amino]-anthracene (abbreviation: 2PCAPA) represented by the above structural formula (xiii) is 1:0.05 (= cgDBCzPA:2PCAPA) to form the first light-emitting layer and the second light-emitting layer.

[0494] (Manufacturing method of comparative light-emitting device G1) The difference between the comparative light-emitting device G1 and the manufacturing method of the light-emitting device G1 is that: the comparative light-emitting device G1 forms the second hole transport layer with a thickness of 60 nm, and co-evaporates 6BP-4Cz2PPm and Liq in a weight ratio of 1:1 (= 6BP-4Cz2PPm:Liq) and a thickness of 25 nm to form the second electron transport layer.

[0495] (Manufacturing method of light-emitting device B1) The manufacturing method of light-emitting device B1 is different from that of light-emitting device R1 in that: for light-emitting device B1, the first hole transport layer is formed with a thickness of 45 nm, the second hole transport layer is formed with a thickness of 45 nm, and co-evaporation is carried out in such a way that 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth) represented by the above structural formula (xiv) and N,N'-diphenyl-N,N'-bis[(9-phenyl-9H-carbazol-2-yl)]naphtho[2,3-b;6,7-b']bisbenzofuran-3,10-diamine (abbreviation: 3,10PCA2Nbf(IV)-02) represented by the above structural formula (xv) have a weight ratio of 1:0.015 (=αN-βNPAnth:3,10PCA2Nbf(IV)-02) and a thickness of 25 nm to form the first light-emitting layer and the second light-emitting layer.

[0496] (Comparative manufacturing method of light-emitting device B1) The difference between the comparative light-emitting device B1 and the manufacturing method of light-emitting device B1 is that: for the comparative light-emitting device B1, the second hole transport layer is formed with a thickness of 55 nm, and 6BP-4Cz2PPm and Liq are co-evaporated with a weight ratio of 1:1 (=6BP-4Cz2PPm:Liq) and a thickness of 25 nm to form the second electron transport layer.

[0497] The device structures of light-emitting device R1, light-emitting device G1, light-emitting device B1, comparative light-emitting device R1, comparative light-emitting device G1, and comparative light-emitting device B1 are shown below.

[0498] [Table 1]

[0499] [Table 2]

[0500] [Table 3]

[0501] Figure 24 The current density-voltage characteristics of light-emitting device R1 and comparative light-emitting device R1 are shown, Figure 25 The current efficiency-luminance characteristics are shown, Figure 26 The power efficiency-luminance characteristics are shown, Figure 27 The electroluminescence spectrum is shown. In addition, Figure 28 The current density-voltage characteristics of light-emitting device G1 and comparative light-emitting device G1 are shown, Figure 29 The current efficiency-luminance characteristics are shown, Figure 30 The power efficiency-luminance characteristics are shown, Figure 31 The electroluminescence spectrum is shown. In addition, Figure 32Shows the current density-voltage characteristics of the light-emitting device B1 and the comparative light-emitting device B1, Figure 33 shows the current efficiency-luminance characteristics, Figure 34 shows the blue light efficiency index-luminance characteristics, Figure 35 shows the power efficiency-luminance characteristics, Figure 36 shows the electroluminescence spectrum.

[0502] Note that the blue light efficiency index (BI) is a value obtained by dividing the current efficiency (cd / A) by the y value of the CIE (x, y) chromaticity, and is one of the indices representing the light-emitting characteristics of blue light emission. Blue light emission has a tendency that the smaller the chromaticity y value, the higher the color purity. By using blue light emission with a small chromaticity y value and high color purity, blue with a wide chromaticity range can be presented on the display, and the brightness of the blue light required to present white on the display decreases. Therefore, the effect of reducing the power consumption of the display can be obtained. Therefore, sometimes it is preferable to use the current efficiency considering the chromaticity y value, which is one of the indices of blue purity, that is, BI, as a method of representing the blue light emission efficiency. Thus, it can be said that the higher the BI of the light-emitting device, the better the efficiency as a blue light-emitting device for a display.

[0503] In addition, Table 4 shows the main characteristics of the light-emitting device R1 and the comparative light-emitting device R1 at around 1000 cd / m 2 Table 5 shows the main characteristics of the light-emitting device G1 and the comparative light-emitting device G1 at around 1000 cd / m 2 Table 6 shows the main characteristics of the light-emitting device B1 and the comparative light-emitting device B1 at around 1000 cd / m 2 Note that the brightness, CIE chromaticity, and electroluminescence spectrum were measured at room temperature using a spectroradiometer (manufactured by Topcon Corporation, SR-UL1R).

[0504] [Table 4]

[0505] From Figures 24 to 27 and Table 4, it can be seen that both the light-emitting device R1 and the comparative light-emitting device R1 can obtain red light emission with a peak wavelength of 625 nm in the electroluminescence spectrum. In addition, it can be seen that both the light-emitting device R1 and the comparative light-emitting device R1 are light-emitting devices with good current efficiency. However, compared with the comparative light-emitting device R1, the driving voltage of the light-emitting device R1 is lower, so its power consumption is lower, the power efficiency is higher, and the characteristics are better. From this, it can be known that the light-emitting device R1 of one embodiment of the present invention is a series-type light-emitting device with good characteristics.

[0506] [Table 5]

[0507] From Figures 28 to 31As can be seen from Table 5, both the light-emitting device G1 and the comparative light-emitting device G1 can achieve green light emission with a peak wavelength of 532 nm in the electroluminescence spectrum. In addition, it can be seen that both the light-emitting device G1 and the comparative light-emitting device G1 are light-emitting devices with good current efficiency. However, compared with the comparative light-emitting device G1, the driving voltage of the light-emitting device G1 is lower, so its power consumption is lower and its characteristics are better. From this, it can be known that the light-emitting device G1 of one embodiment of the present invention is a tandem-type light-emitting device with good characteristics.

[0508] [Table 6]

[0509] From Figures 32 to 36 As can be seen from Table 6, the light-emitting device B1 and the comparative light-emitting device B1 can respectively achieve blue light emission with peak wavelengths of 454 nm and 457 nm in the electroluminescence spectrum. In addition, it can be seen that both the light-emitting device B1 and the comparative light-emitting device B1 are light-emitting devices with good current efficiency. However, compared with the comparative light-emitting device B1, the driving voltage of the light-emitting device B1 is lower, so its power consumption is lower and its characteristics are better. In addition, it can be seen that the light-emitting device B1 is a light-emitting device with good blue light efficiency index. From this, it can be known that as the light-emitting device constituting the blue sub-pixel of the display device, the light-emitting device B1 of one embodiment of the present invention is a tandem-type light-emitting device with good characteristics. In addition, it can be seen that the light-emitting device B1 has good characteristics especially when the actual brightness is 500 cd / cm 2 or more.

[0510] Here, the second electron transport layer of the light-emitting device R1, the light-emitting device G1, and the light-emitting device B1 contains the same material (the first organic compound containing a triazine skeleton). Thus, in the light-emitting device of one embodiment of the present invention, even if the second electron transport layer is composed of the same material in the light-emitting devices emitting different colors of light, each light-emitting device can have good characteristics.

[0511] Next, assume the following two display devices respectively to estimate the power consumption of the display unit (excluding the power consumption of the driving transistor and the driving circuit, etc.). One is the display device of the embodiment that uses the light-emitting device R1, the light-emitting device G1, and the light-emitting device B1 for the red, green, and blue sub-pixels respectively, and the other is the comparative display device that uses the comparative light-emitting device R1, the comparative light-emitting device G1, and the comparative light-emitting device B1 respectively. In the above two display devices, each light-emitting device used is a tandem-type light-emitting device, and the light-emitting center substances contained in the multiple light-emitting layers included in each light-emitting device are the same. Therefore, it is a display device adopting a separate coating method.

[0512] The conditions of the display device assumed for estimation are as follows.

[0513] [Table 7]

[0514] First, in the display device under the above conditions, find the brightness (effective brightness) of the light-emitting devices of each color in the following case: when the entire screen emits light, it can reach 1000 cd / m 2 Obtain white light emission with CIE1931 chromaticity coordinates of chromaticity (x, y) = (0.31, 0.33).

[0515] Next, considering the aperture ratio, calculate the brightness (intrinsic brightness) required for each color light-emitting device to obtain the obtained effective brightness. The intrinsic brightness refers to the brightness at which each light-emitting device actually emits light in the following case: when the entire screen emits light, it can reach an effective brightness of 1000 cd / m 2 Obtain white light emission with CIE1931 chromaticity coordinates of chromaticity (x, y) = (0.31, 0.33). The total aperture ratio of the display device for estimation is 30%, and the aperture ratio of each light-emitting color is 10%. Therefore, the intrinsic brightness is about 10 times the effective brightness.

[0516] Based on the measurement results of the above light-emitting devices, the current density and voltage used to make the light-emitting devices emit light at this brightness can be obtained using the intrinsic brightness. That is, in the display device under the above conditions, the current density and voltage of the light-emitting devices in the following case can be obtained: when the entire screen emits light, it can reach a brightness of 1000 cd / m 2 Obtain white light emission with CIE1931 chromaticity coordinates of chromaticity (x, y) = (0.31, 0.33).

[0517] The power consumption can be obtained from the product of the current amount and the voltage. The current amount can be obtained from the product of the current density, the panel area, and the aperture ratio. The size of the display device for estimation is 5 inches in diagonal, the aspect ratio is 16:9, and the panel area is 68.9 cm 2 , and the aperture ratio of the light-emitting devices of each color is 10%. Therefore, by multiplying the current density obtained in the previous paragraph by them, the current amount can be calculated, and by further multiplying the voltage obtained in the previous paragraph, the power consumption of the light-emitting devices of each light-emitting color can be calculated. By calculating the power consumption of the light-emitting devices of each color and adding them together, the power consumption of the entire display section of the display device (excluding the power consumption of the driving transistors and driving circuits, etc.) can be obtained.

[0518] Table 8 shows the calculation results of the power consumption of the display device in the embodiment assuming the use of light-emitting device R1, light-emitting device G1, and light-emitting device B1, and Table 9 shows the calculation results of the power consumption of the display device in the comparative example assuming the use of comparative light-emitting device R1, comparative light-emitting device G1, and comparative light-emitting device B1.

[0519] [Table 8] Example

[0520] [Table 9] Comparative Example

[0521] As can be seen from Table 8 and Table 9, compared with the display device of the comparative example, the display device of the example has higher current efficiency of white light emission and lower driving voltage. In addition, it can be seen that the power consumption of the display device of the example is lower than that of the display device of the comparative example.

[0522] From this, it can be known that a display device using the following tandem light-emitting device has low power consumption and good characteristics: in the tandem light-emitting device, the second electron transport layer has a first organic compound containing a triazine skeleton, the intermediate layer includes a mixed layer of a second organic compound having a phenanthroline skeleton and lithium or a lithium compound, and the difference in the maximum peak wavelength in the emission spectra of the lights emitted by the plurality of light-emitting layers is 30 nm or less.

Claims

1. A light emitting device, comprising: a first electrode; a second electrode; Middle layer; a first light-emitting layer; a second light-emitting layer; a first electron transport layer; as well as The second electron transport layer, Wherein, the intermediate layer is between the first electrode and the second electrode, The first light-emitting layer is between the first electrode and the intermediate layer, The second light-emitting layer is between the intermediate layer and the second electrode, The first electron transport layer is between the first light-emitting layer and the intermediate layer, The second electron transport layer is between the second light-emitting layer and the second electrode, The second electron transport layer has at least a stacked structure of a third electron transport layer and a fourth electron transport layer, The fourth electron transport layer is between the third electron transport layer and the second electrode, The intermediate layer includes a mixed layer of a second organic compound and one of lithium and a lithium compound, The second organic compound has a phenanthroline skeleton, The first light-emitting layer includes a first light-emitting center substance, The second light-emitting layer includes a second light-emitting center substance, The difference between the maximum peak wavelength of the emission spectrum of the first luminescence center substance and the maximum peak wavelength of the emission spectrum of the second luminescence center substance is 30 nm or less, Furthermore, the first light-emitting layer and the second light-emitting layer are different from the light-emitting layer of at least one of the adjacent plurality of light-emitting devices. 2 . The light emitting device according to claim 1 , wherein the fourth electron transport layer comprises a first organic compound having a triazine skeleton. The light emitting device according to claim 1 , wherein the fourth electron transport layer comprises one of lithium and a lithium compound. The light-emitting device according to claim 1 , wherein the first luminescence center substance is the same as the second luminescence center substance. The light emitting device according to claim 1 , wherein the intermediate layer comprises a first layer including the second organic compound.

6. The light emitting device according to claim 5, wherein the middle layer further comprises a second layer, And the second layer is between the first layer and the second light-emitting layer. The light-emitting device according to claim 6 , wherein the second layer comprises a fourth organic compound having a hole transport property. 8 . The light emitting device according to claim 7 , wherein the second layer comprises an organic compound having a halogen group and / or a cyano group.

9. The light emitting device according to claim 1, The first electron transport layer has at least a stacked structure of a fifth electron transport layer and a sixth electron transport layer, And the sixth electron transport layer is between the fifth electron transport layer and the intermediate layer. 10 . The light emitting device according to claim 9 , wherein the sixth electron transport layer comprises a third organic compound having a triazine skeleton.

11. A light emitting device, comprising: a first electrode; a second electrode; Middle layer; a first light-emitting layer; a second light-emitting layer; a first electron transport layer; as well as The second electron transport layer, Wherein, the intermediate layer is between the first electrode and the second electrode, The first light-emitting layer is between the first electrode and the intermediate layer, The second light-emitting layer is between the intermediate layer and the second electrode, The first electron transport layer is between the first light-emitting layer and the intermediate layer, The second electron transport layer is between the second light-emitting layer and the second electrode, The second electron transport layer has at least a stacked structure of a third electron transport layer and a fourth electron transport layer, The fourth electron transport layer is between the third electron transport layer and the second electrode, The fourth electron transport layer includes a first organic compound having a triazine skeleton, The first electron transport layer comprises a third organic compound having a triazine skeleton, The intermediate layer comprises a second organic compound having a phenanthroline skeleton, The first light-emitting layer includes a first light-emitting center substance, The second light-emitting layer includes a second light-emitting center substance, The difference between the maximum peak wavelength of the emission spectrum of the first luminescence center substance and the maximum peak wavelength of the emission spectrum of the second luminescence center substance is 30 nm or less, Furthermore, the first light-emitting layer and the second light-emitting layer are different from the light-emitting layer of at least one of the adjacent plurality of light-emitting devices. 12 . The light emitting device according to claim 11 , wherein the first organic compound is the same as the third organic compound. The light emitting device according to claim 11 , wherein the intermediate layer comprises one of lithium and a lithium compound. 14 . The light emitting device according to claim 13 , wherein the intermediate layer comprises a mixed layer of the second organic compound and one of the lithium and the lithium compound. The light emitting device according to claim 11 , wherein the fourth electron transport layer comprises one of lithium and a lithium compound. The light emitting device according to claim 11 , wherein the first luminescence center substance is the same as the second luminescence center substance. The light emitting device according to claim 11 , wherein the intermediate layer comprises a first layer including the second organic compound.

18. The light emitting device according to claim 17, wherein the middle layer further comprises a second layer, And the second layer is between the first layer and the second light-emitting layer. The light emitting device according to claim 18 , wherein the second layer comprises a fourth organic compound having a hole transport property. 20 . The light emitting device according to claim 19 , wherein the second layer comprises an organic compound having a halogen group and / or a cyano group.

21. The light emitting device according to claim 11, The first electron transport layer has at least a stacked structure of a fifth electron transport layer and a sixth electron transport layer, And the sixth electron transport layer is between the fifth electron transport layer and the intermediate layer. 22 . The light emitting device according to claim 21 , wherein the sixth electron transport layer comprises a third organic compound having a triazine skeleton.

23. A display device, comprising: a first light emitting device; as well as a second light emitting device, wherein the first light emitting device is adjacent to the second light emitting device, The first light emitting device comprises: a first electrode; a second electrode; First intermediate layer; a first light-emitting layer; a second light-emitting layer; a first electron transport layer; and The second electron transport layer, The first intermediate layer is between the first electrode and the second electrode, The first light-emitting layer is between the first electrode and the first intermediate layer, The second light-emitting layer is between the first intermediate layer and the second electrode, The first electron transport layer is between the first light-emitting layer and the first intermediate layer, the second electron transport layer is between the second light-emitting layer and the second electrode, and the second electron transport layer has a stacked structure of at least a third electron transport layer and a fourth electron transport layer. The fourth electron transport layer is between the third electron transport layer and the second electrode, and the second light emitting device includes: a third electrode; a fourth electrode; Second intermediate layer; A third light emitting layer; a fourth light-emitting layer; a fifth electron transport layer; and The sixth electron transport layer, The second intermediate layer is between the third electrode and the fourth electrode, The third light-emitting layer is between the third electrode and the second intermediate layer, The fourth light emitting layer is between the second intermediate layer and the fourth electrode, The fifth electron transport layer is between the third light-emitting layer and the second intermediate layer, the sixth electron transport layer is between the fourth light-emitting layer and the fourth electrode, and the sixth electron transport layer has a stacked structure of at least a seventh electron transport layer and an eighth electron transport layer, The eighth electron transport layer is between the seventh electron transport layer and the fourth electrode, the fourth electron transport layer and the eighth electron transport layer are made of the same material, the first intermediate layer and the second intermediate layer both contain a second organic compound and one of lithium and a lithium compound, The second organic compound has a phenanthroline skeleton, The first light-emitting layer includes a first light-emitting center substance, The second light-emitting layer includes a second light-emitting center substance, The third light-emitting layer comprises a third light-emitting center substance, The fourth light-emitting layer includes a fourth light-emitting center substance, The difference between the maximum peak wavelength of the emission spectrum of the first luminescence center substance and the maximum peak wavelength of the emission spectrum of the second luminescence center substance is 30 nm or less, The difference between the maximum peak wavelength of the emission spectrum of the third luminescence center substance and the maximum peak wavelength of the emission spectrum of the fourth luminescence center substance is 30 nm or less, The first light-emitting layer is different from the third light-emitting layer, Furthermore, the second light-emitting layer is different from the fourth light-emitting layer. 24 . The display device according to claim 23 , wherein the second electron transport layer and the sixth electron transport layer are continuous layers.

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