Light-emitting device and display device

Abstract

To provide a light-emitting device with excellent characteristics.SOLUTION: A light-emitting device includes a first electrode, a second electrode, an intermediate layer therebetween, a first light-emitting layer, a second light-emitting layer, a first electron transport layer, and a second electron transport layer. The first light-emitting layer exists between the first electrode and the intermediate layer, the second light-emitting layer exists between the intermediate layer and the second electrode, the first electron transport layer exists between the first light-emitting layer and the intermediate layer, the second electron transport layer exists between the second light-emitting layer and the second electrode, the second electron transport layer has a multilayer structure, the intermediate layer includes a second organic compound with a phenanthroline skeleton, the first light-emitting layer and the second light-emitting layer have the same light-emitting central material, 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 a plurality of light-emitting devices that is adjacent to the aforementioned light-emitting device.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] One aspect of the present invention relates to an organic compound, an organic semiconductor device, 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. The technical field of one aspect of the invention disclosed in this specification or the like relates to an object, a method, or a manufacturing method. Alternatively, one aspect of the present invention relates to a process, a machine, a manufacture, or a composition of matter. Therefore, more specifically, examples of the technical field of one aspect of the present invention disclosed in this specification include a semiconductor device, a display device, a liquid crystal display device, a lighting device, a power storage device, a storage device, an imaging device, a driving method thereof, or a manufacturing method thereof.

Background Art

[0002] The practical application of light-emitting devices (also referred to as organic EL devices) that utilize electroluminescence (EL) using organic compounds has been progressing. The basic configuration of these light-emitting devices is such that an organic compound layer containing a light-emitting center substance is sandwiched between a pair of electrodes. By applying a voltage to this device to inject carriers and utilizing the recombination energy of the carriers, light emission from the light-emitting center substance can be obtained.

[0003] Since the light-emitting device is self-luminous, a display device using the light-emitting device as a pixel 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 lightweight, which is also a great advantage. Furthermore, it is also characterized by a very fast response speed.

[0004] In addition, since these light-emitting devices can form a light-emitting layer continuously in a planar shape, planar light emission can be obtained. This is a characteristic that is difficult to achieve with point light sources typified by incandescent bulbs and LEDs, or line light sources typified by fluorescent lamps. Therefore, it has high utility value as a surface light source that can be applied to lighting and the like.

[0005] As described above, display devices and lighting devices using such light-emitting devices are suitable for various electronic devices, and research and development are being advanced to obtain light-emitting devices with better characteristics.

[0006] In particular, tandem-type light-emitting devices have attracted attention because they can achieve high current efficiency. Patent Document 1 and Patent Document 2 disclose tandem-type light-emitting devices using a coating method.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] One aspect of the present invention aims to provide a light-emitting device with good characteristics. Or, one aspect of the present invention aims to provide a light-emitting device with good luminous efficiency. Or, one aspect of the present invention aims to provide a light-emitting device with good reliability. Or, one aspect of the present invention aims to provide a light-emitting device with a low driving voltage. Or, one aspect of the present invention aims to provide a light-emitting device with good reliability and a low driving voltage.

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

[0010] Alternatively, an object 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. Alternatively, an object is to provide either a highly reliable electronic device or a lighting device. Alternatively, an object 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 solve any one of the above problems. Note that the description of these problems does not prevent the existence of other problems. Note that one aspect of the present invention does not need to solve all of these problems. Note that other problems will be naturally revealed from the descriptions in the specification, drawings, claims, etc., and it is possible to extract these other problems from the descriptions in the specification, drawings, claims, etc.

Means for Solving the Problems

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

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

[0014] Alternatively, another aspect of the present invention is a light-emitting device having 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, wherein 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 a stacked structure of at least a second a electron transport layer and a second b electron transport layer, the second b electron transport layer is located between the second a electron transport layer and the second electrode, the second b 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 having a phenanthroline skeleton, the first light-emitting layer has a first light-emitting center substance, the second light-emitting layer has a second light-emitting center substance, the difference between the maximum peak wavelength in the emission spectrum of the first light-emitting center substance and the maximum peak wavelength in 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 light-emitting layers different from the light-emitting layers of at least one of a plurality of other light-emitting devices adjacent to the light-emitting device.

[0015] Alternatively, another aspect of the present invention is a light-emitting device in the above configuration, wherein the intermediate layer has lithium or a lithium compound.

[0016] Alternatively, another aspect of the present invention is a light-emitting device in the above configuration, wherein the intermediate layer has a mixed layer of the second organic compound and lithium or a lithium compound.

[0017] Alternatively, another aspect of the present invention is a light-emitting device in the above configuration, wherein the second b electron transport layer has lithium or a lithium compound.

[0018] Alternatively, another aspect of the present invention is a light-emitting device in the above configuration, wherein the first light-emitting center substance and the second light-emitting center substance are the same substance.

[0019] Alternatively, in another aspect of the present invention, in the above configuration, the intermediate layer is a light-emitting device having a first layer containing a second organic compound.

[0020] Alternatively, in another aspect of the present invention, in the above configuration, the intermediate layer further has a second layer, and the second layer is a light-emitting device located between the first layer and the second light-emitting layer.

[0021] Alternatively, in another aspect of the present invention, in the above configuration, the second layer is a light-emitting device containing a fourth organic compound having hole-transporting properties.

[0022] Alternatively, in another aspect of the present invention, in the above configuration, the second layer is a light-emitting device containing a halogen.

[0023] Alternatively, in another aspect of the present invention, in the above configuration, the second layer is a light-emitting device containing an organic compound having at least one of a halogen group and a cyano group.

[0024] Alternatively, in another aspect of the present invention, in the above configuration, the second layer is a light-emitting device containing an organic compound having at least one of fluorine and a cyano group.

[0025] Alternatively, in another aspect of the present invention, in the above configuration, the second layer is a light-emitting device containing an organic compound having at least four of a halogen group and a cyano group.

[0026] Alternatively, in another aspect of the present invention, in the above configuration, the second layer is a light-emitting device containing an organic compound having at least four of fluorine and a cyano group.

[0027] Alternatively, in another aspect of the present invention, in the above configuration, the first electron transport layer has at least a stacked structure of a first a electron transport layer and a first b electron transport layer, and the first b electron transport layer is a light-emitting device located between the first a electron transport layer and the intermediate layer.

[0028] Alternatively, another aspect of the present invention is a light-emitting device in the above configuration, wherein the first electron transport layer has a third organic compound containing a triazine skeleton.

[0029] Alternatively, another aspect of the present invention is a light-emitting device in the above configuration, wherein the first organic compound and the third organic compound are the same organic compound.

[0030] Alternatively, another aspect of the present invention is a display device including the light-emitting device according to any one of the above.

[0031] Alternatively, another aspect of the present invention is a display device having a light-emitting device A and a light-emitting device B, wherein the light-emitting device A and the light-emitting device B are adjacent to each other. The light-emitting device A includes a first electrode A, a second electrode A, an intermediate layer A, a first light-emitting layer A, a second light-emitting layer A, a first electron transport layer A, and a second electron transport layer A. The intermediate layer A is located between the first electrode A and the second electrode A. The first light-emitting layer A is located between the first electrode A and the intermediate layer A. The second light-emitting layer A is located between the intermediate layer A and the second electrode A. The first electron transport layer A is located between the first light-emitting layer A and the intermediate layer A. The second electron transport layer A is located between the second light-emitting layer A and the second electrode A. The second electron transport layer A has a stacked structure including at least a 2a electron transport layer A and a 2b electron transport layer A. The 2b electron transport layer A is located between the 2a electron transport layer A and the second electrode A. The light-emitting device B includes a first electrode B, a second electrode B, an intermediate layer B, a first light-emitting layer B, a second light-emitting layer B, a first electron transport layer B, and a second electron transport layer B. The intermediate layer B is located between the first electrode B and the second electrode B. The first light-emitting layer B is located between the first electrode B and the intermediate layer B. The second light-emitting layer B is located between the intermediate layer B and the second electrode B. The first electron transport layer B is located between the first light-emitting layer B and the intermediate layer B. The second electron transport layer B is located between the second light-emitting layer B and the second electrode B. The second electron transport layer B has a stacked structure including at least a 2a electron transport layer B and a 2b electron transport layer B. The 2b electron transport layer B is located between the 2a electron transport layer B and the second electrode B. The 2b electron transport layer A and the 2b electron transport layer B are made of the same material. The intermediate layer A and the intermediate layer B include a second organic compound having a phenanthroline skeleton and lithium or a lithium compound. The first light-emitting layer A has a first light-emitting center substance. The second light-emitting layer A has a second light-emitting center substance. The first light-emitting layer B has a third light-emitting center substance. The second light-emitting layer B has a fourth light-emitting center substance. The difference between the maximum peak wavelength in the emission spectrum of the first light-emitting center substance and the maximum peak wavelength in the emission spectrum of the second light-emitting center substance is 30 nm or less. The difference between the maximum peak wavelength in the emission spectrum of the third light-emitting center substance and the maximum peak wavelength in the emission spectrum of the fourth light-emitting center substance isA display device in which the thickness is 30 nm or less, and the first light-emitting layer A and the first light-emitting layer B, and the second light-emitting layer A and the second light-emitting layer B are different light-emitting layers respectively.

[0032] Alternatively, another aspect of the present invention is a display device having a light-emitting device A and a light-emitting device B, wherein the light-emitting device A and the light-emitting device B are adjacent to each other. The light-emitting device A includes a first electrode A, a second electrode A, an intermediate layer A, a first light-emitting layer A, a second light-emitting layer A, a first electron transport layer A, and a second electron transport layer A. The intermediate layer A is located between the first electrode A and the second electrode A. The first light-emitting layer A is located between the first electrode A and the intermediate layer A. The second light-emitting layer A is located between the intermediate layer A and the second electrode A. The first electron transport layer A is located between the first light-emitting layer A and the intermediate layer A. The second electron transport layer A is located between the second light-emitting layer A and the second electrode A. The second electron transport layer A has a stacked structure including at least a second a electron transport layer A and a second b electron transport layer A. The second b electron transport layer A is located between the second a electron transport layer A and the second electrode A. The light-emitting device B includes a first electrode B, a second electrode B, an intermediate layer B, a first light-emitting layer B, a second light-emitting layer B, a first electron transport layer B, and a second electron transport layer B. The intermediate layer B is located between the first electrode B and the second electrode B. The first light-emitting layer B is located between the first electrode B and the intermediate layer B. The second light-emitting layer B is located between the intermediate layer B and the second electrode B. The first electron transport layer B is located between the first light-emitting layer B and the intermediate layer B. The second electron transport layer B is located between the second light-emitting layer B and the second electrode B. The second electron transport layer B has a stacked structure including at least a second a electron transport layer B and a second b electron transport layer B. The second b electron transport layer B is located between the second a electron transport layer B and the second electrode B. The second electron transport layer A and the second electron transport layer B are a continuous layer. The intermediate layer A and the intermediate layer B contain a second organic compound having a phenanthroline skeleton and lithium or a lithium compound. The first light-emitting layer A contains a first light-emitting central substance. The second light-emitting layer A contains a second light-emitting central substance. The first light-emitting layer B contains a third light-emitting central substance. The second light-emitting layer B contains a fourth light-emitting central substance. The difference between the maximum peak wavelength in the emission spectrum of the first light-emitting central substance and the maximum peak wavelength in the emission spectrum of the second light-emitting central substance is 30 nm or less. The difference between the maximum peak wavelength in the emission spectrum of the third light-emitting central substance and the maximum peak wavelength in the emission spectrum of the fourth light-emitting central substance isA display device having a thickness of 30 nm or less, wherein the first light-emitting layer A and the first light-emitting layer B, and the second light-emitting layer A and the second light-emitting layer B are different light-emitting layers respectively.

[0033] Or, another aspect of the present invention is an electronic device having the above light-emitting device, a sensor, an operation button, a speaker, or a microphone.

[0034] Or, another aspect of the present invention is a lighting device having the above light-emitting device and a housing.

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

Advantages of the Invention

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

[0037] Or, in one aspect of the present invention, a light-emitting device capable of providing a display device with good characteristics can be provided. Or, in one aspect of the present invention, a light-emitting device capable of providing a display device with good luminous efficiency can be provided. Or, in one aspect of the present invention, a light-emitting device capable of providing a display device with good reliability can be provided. Or, in one aspect of the present invention, a light-emitting device capable of providing a display device with a low driving voltage can be provided. Or, in 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] Alternatively, it is possible 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 that consume low power. Alternatively, it is possible to provide any one of a highly reliable electronic device and a lighting device.

Brief Description of the Drawings

[0039]

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BEST MODE FOR CARRYING OUT THE INVENTION

[0040] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and those skilled in the art can easily understand that the form and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention is not to be construed as being limited to the description of the embodiments shown below.

[0041] In this specification and the like, a device manufactured using a metal mask or an FMM (fine metal mask, high-definition metal mask) may be referred to as a device having an MM (metal mask) structure. In this specification and the like, a device manufactured without using a metal mask or an FMM may be referred to as a device having an MML (metal maskless) structure.

[0042] (Embodiment 1) A tandem 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 has a light-emitting layer, and light emission can be obtained from any of the light-emitting layers by passing an electric current. A tandem light-emitting device having such a configuration has a significantly higher current efficiency compared to a non-tandem light-emitting device, and thus can be suitably used for a display device that requires high-brightness display or a display device that requires high reliability.

[0043] Since a tandem light-emitting device has a plurality of light-emitting layers and it is easy to obtain white light emission, the full-colorization method of a display device using a tandem light-emitting device often adopts the white color filter method. In addition, a color conversion method in which a light-emitting layer that exhibits blue light emission is stacked and a color conversion layer typified by quantum dots is used has also been put into practical use.

[0044] On the other hand, a display device using a tandem light-emitting device and adopting a dispensing method as a full-colorization method has also been partially put into practical use. Since the dispensing method light-emitting device has no or little energy loss in the color filter or the color conversion layer, it is possible to obtain a light-emitting device with better light emission efficiency than 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 configuration having a second organic compound containing a phenanthroline skeleton.

[0046] In addition, the light-emitting layer of the tandem light-emitting device preferably is separated from the light-emitting layer of at least one of the other adjacent light-emitting devices. Alternatively, the light-emitting layer of the tandem light-emitting device preferably is a light-emitting layer different from the light-emitting layer of at least one of the other adjacent light-emitting devices. Alternatively, the emission color emitted by the tandem light-emitting device or the pixel having the tandem light-emitting device preferably is different from the emission color emitted by at least one of the other adjacent light-emitting devices or pixels. Alternatively, the light-emitting central substance included in the light-emitting layer of the tandem light-emitting device preferably has a configuration different from that of the light-emitting central substance included in the light-emitting layer of at least one of the other adjacent light-emitting devices.

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

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

[0049] In addition, the electron transport layer included in the light-emitting unit on the anode side may have a laminated structure or a single-layer structure. However, having a laminated structure enables high current efficiency, lower power consumption, and the provision of a light-emitting device with good characteristics. In the case of a single-layer structure, the number of film-forming chambers is small, which is advantageous from the perspective of manufacturing cost.

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

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

[0052] Examples of the monocyclic aromatic ring include a benzene ring, a pyrrole ring, a pyridine ring, a pyrimidine ring, etc. Further, as the polycyclic aromatic ring, in addition to aromatic hydrocarbon rings such as a naphthalene ring, a phenanthrene ring, a chrysene ring, a triphenylene ring, a fluorene ring, it preferably contains a heterocyclic aromatic ring such as a phenanthroline ring, a pyrrole ring, etc. In particular, it is preferable to contain a plurality of these polycyclic aromatic rings because the heat resistance and electron transport property can be improved.

[0053] As the second organic compound containing a phenanthroline skeleton, for example, bathophenanthroline (abbreviation: Bphen), bathocuproine (abbreviation: BCP), 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), 2-[3-(2-triphenylenyl)phenyl]-1,10-phenanthroline (abbreviation: mTpPPhen), 2-phenyl-9-(2-triphenylenyl)-1,10-phenanthroline (abbreviation: Ph-TpPhen), 2-[4-(9-phenanthrenyl)-1-naphthalenyl]-1,10-phenanthroline (abbreviation: PnNPhen), 2-[4-(2-triphenylenyl)phenyl]-1,10-phenanthroline (abbreviation: pTpPPhen), etc., organic compounds containing a heterocyclic aromatic ring having a phenanthroline skeleton can be used, and PnNPhen (200), mPPhen2P (201), etc. represented by the following structural formulas (200) to (201) are particularly preferable.

[0054]

Chemical formula

[0055] In a light-emitting device according to one aspect of the present invention, the intermediate layer has a second organic compound containing a phenanthroline skeleton, and by applying a voltage between the first electrode and the second electrode, electrons can be injected into the light-emitting unit on the anode side in contact with the intermediate layer, and holes can be injected into the light-emitting unit on the cathode side. Any configuration may be used as long as it is a layer that can perform such injection. However, the intermediate layer preferably has a laminated structure including a first layer containing the 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 preferably includes alkali metals (Group 1 elements) such as Li, alkaline earth metals (Group 2 elements) such as Mg and Ca, Group 3 elements including lanthanoids 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] The first layer may have a laminated structure of 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. However, the mixed layer is preferable because it requires fewer deposition chambers and can reduce manufacturing costs, and it also contributes to improving the stability of the light-emitting device.

[0058] When the organic compound is mixed with the metal or the metal compound, when the first layer is analyzed in the film thickness direction, the distribution of the organic compound and the distribution of the metal or the metal compound generally show the same tendency. That is, when the distribution of the organic compound is constant, the distribution of the metal or the metal compound is also generally constant. In the case of a laminated structure of a layer containing an organic compound and a layer containing a metal or a metal compound, the metal or the metal compound may be detected in a region other than the layer due to diffusion from the layer containing the metal or the metal compound. However, since the distribution shows a different distribution from that of the organic compound, the analysis results can be separated into diffusion and mixing.

[0059] Also, when analyzing the first layer in the film thickness direction, if there is a region where a metal or a metal compound is detected and the region is 10 nm or more, preferably 15 nm or more, more preferably 20 nm or more, the first layer can be regarded as having a mixed layer in which an organic compound and a metal or a metal compound are mixed.

[0060] The metal in the above metal or metal compound is preferably a substance that exhibits donor properties to the second organic compound. Examples of substances that exhibit donor properties to the second organic compound include metals of Group 1 and Group 2, and lithium or a lithium compound is particularly preferred. Specifically, Li, lithium fluoride (LiF), lithium oxide (Li2O), and 8-hydroxyquinolinato-lithium (abbreviation: Liq) are preferred. When the first layer is a layer containing 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. Thereby, the light-emitting device of one aspect of the present invention can be a light-emitting device with a low driving voltage.

[0061] In addition to the organic compounds described above, the second organic compound preferably includes an organic compound containing a phenanthroline skeleton having a substituent with electron-donating properties. The phenanthroline skeleton is a skeleton that easily interacts with a metal or the like. By further having an electron-donating group in the second organic compound containing such a phenanthroline skeleton, the electron density of the phenanthroline skeleton can be increased, and the interaction with a metal or a metal compound can be further facilitated. In particular, when using a metal of Group 3, Group 11, Group 12, or Group 13 as the metal in the metal or metal compound, it is possible to suppress an increase in the driving voltage and provide a tandem-type light-emitting device having good characteristics.

[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, etc. However, the preferred electron-donating groups introduced into the phenanthroline ring are not limited to these. Any group that can increase the electron density of the phenanthroline ring by being introduced into the phenanthroline ring can be applied as an electron-donating group. Further, the electron-donating group may be introduced into the phenanthroline ring via an arylene group such as a phenylene group, and the p-phenylene group is preferred as the arylene group.

[0063] Specific examples of the organic compound containing a phenanthroline skeleton having a substituent with electron-donating property are shown in Structural Formulas (300) to (310).

[0064]

Chemical formula

[0065] The electron transport layer included in the light-emitting unit on the cathode side has a laminated structure as described above. Among the laminated layers, it is preferable that the layer on the cathode side contains a first organic compound containing a triazine skeleton.

[0066] The first organic compound containing the above triazine skeleton can be used as long as it has higher electron transport property than hole. However, the electron mobility at the square root of the electric field strength [V / cm] being 600 is preferably 1×10 -7 cm 2 / Vs or more, preferably 1×10 -6 cm 2 / Vs or more, and preferably has electron transport property.

[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, it is preferable to use a monocyclic aromatic ring, a polycyclic aromatic ring, an aromatic ring having an alkyl group as a substituent, an aromatic ring having a fluoro group as a substituent, an aromatic ring having a cyano group as a substituent, and the like. The triazine skeleton may have a substituent other than the above aromatic ring, and the aromatic ring may have a substituent other than the above fluoro group, cyano group, or alkyl group. Note that the triazine skeleton is also called a triazine ring, and for other skeletons, the skeleton can be rephrased as a ring.

[0068] Examples of the monocyclic aromatic ring include aromatic hydrocarbon rings such as benzene rings, or heteroaromatic rings such as pyrrole rings, pyridine rings, pyrimidine rings, and triazine rings. Having an aromatic ring as a substituent has effects such as improving heat resistance, specifically improving the glass transition temperature (Tg), and improving electron transport properties.

[0069] Examples of the polycyclic aromatic ring include aromatic hydrocarbon rings such as naphthalene rings, phenanthrene rings, chrysene rings, triphenylene rings, fluorene rings, spirobifluorene rings, etc., and heteroaromatic rings such as carbazole rings, dibenzofuran rings, dibenzothiophene rings, xanthene rings, indolocarbazole rings, indenocarbazole rings, etc. A compound having a polycyclic aromatic ring as a substituent is preferable because it can improve heat resistance compared to a compound having a monocyclic aromatic ring such as a benzene ring. In addition, in the case of a compound having a ring in which an aromatic ring (benzene ring, naphthalene ring, pyridine ring, etc.) is further condensed with these polycyclic aromatic rings as a substituent, the heat resistance can be further improved. Examples of the ring in which an aromatic ring is further condensed with the polycyclic aromatic ring include benzofluorene rings, benzonaphthofuran rings, benzoxanthene rings, benzonaphthothiophene rings, etc. By providing a layer having a compound with high heat resistance near the cathode, damage to the device due to heat can be suppressed when performing high-temperature treatments such as patterning processes after forming the layer or the cathode.

[0070] Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a tertiary butyl group, a cyclohexyl group, and an adamantyl group. The first organic compound having an alkyl group as a substituent can be an organic compound with a low refractive index, and the layer using the first organic compound can have a low refractive index. Therefore, total reflection at the interface between the layer and another layer can be reduced, and the light extraction efficiency of the light-emitting device using the layer can be improved. Further, an organic compound having a plurality of carbon atoms, preferably 3 or more, more preferably 4 or more, and still more preferably 5 or more carbon atoms as the alkyl group can enhance the effect of lowering the refractive index.

[0071] Moreover, by also using these compounds having an alkyl group in 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 in the electron transport layer and further using a compound having an aromatic amine skeleton and an alkyl group in the hole transport layer, the effect of improving the light extraction efficiency can be synergistically enhanced.

[0072] In addition, a layer using a compound having a fluoro group as a substituent is also preferable because it can have a low refractive index. In particular, an organic compound having a plurality of fluoro groups can enhance the refractive index reduction effect. It is also effective to use a compound having a fluoro group in both the electron transport layer and the hole transport layer.

[0073] In addition, a compound containing a structure in which a plurality of alkyl groups or fluoro groups are bonded to one aromatic ring can further lower the refractive index of the layer. For example, a structure in which two or more tertiary butyl groups are bonded as substituents to one benzene ring can be mentioned. Not limited to the benzene ring, a structure in which a plurality of alkyl groups or fluoro groups are bonded to other monocyclic aromatic rings such as a pyridine ring, or polycyclic aromatic rings such as a fluorene ring may also be used. Also, for polycyclic aromatic rings (such as naphthalene ring, fluorene ring, carbazole ring, quinoline ring, xanthene ring, etc.), it is also preferable to have a structure in which a plurality of alkyl groups or fluoro groups are bonded to some of the constituent rings. For example, a structure in which a plurality of tertiary butyl groups are bonded to one benzene ring constituting the fluorene ring can be mentioned.

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

[0075] In addition, it is also preferable to combine a plurality of polycyclic aromatic rings, alkyl groups, fluoro groups, or cyano groups as substituents of the first organic compound. For example, when having a polycyclic aromatic ring and a cyano group as substituents, both heat resistance and electron transport properties can be improved. Also, 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 and used 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 that case, it is preferable that the first organic compound includes the aromatic hydrocarbon ring and the heteroaromatic ring.

[0077] Specific examples of the first organic compound containing a triazine skeleton include, 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-fluorene-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-inden[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-pyridinyl)-5-(9-phenanthrenyl)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-naphthalenyl)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), 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,Organic compounds containing a heteroaromatic ring having a triazine skeleton such as [[5-[1,2,4]triazin-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. can be used, but those represented by the following structural formulas (100) to (106), such as TznP2N(100), mSbfxBPTzn(101), mpCNBP-SFxTzn(102), CNBPNPTzn(103), βNP-SFx(4)Tzn(104), mmtBuBP-mDMePyPTzn(105), mBnfBPTzn(106), etc. are particularly preferred. In addition, organic compounds in which the above-mentioned organic compounds are appropriately deuterated can also be used in the same manner.,

[0078]

Chemical formula

[0079] Note that the electron transport layer included in the light-emitting unit on the anode side may have a laminated structure or a single-layer structure as described above. When having a laminated structure, among the layers included in the laminated structure, the layer located on the intermediate layer side is preferably a layer containing a third organic compound containing a triazine skeleton for reducing the driving voltage and power consumption, and is preferably a layer containing a fourth organic compound not containing a triazine skeleton because the electron transport property from the intermediate layer can be appropriately controlled.,

[0080] Note that a configuration in which the first layer has a first group or a second group, particularly lithium or a lithium compound, and a second organic compound containing a phenanthroline skeleton having an electron-donating substituent is preferred because it can provide a tandem type light-emitting device with a lower driving voltage and good reliability. Furthermore, a configuration in which the first layer has a first group or a second group, particularly lithium or a lithium compound, and a second organic compound containing a phenanthroline skeleton having an electron-donating substituent is a preferred configuration because it can suppress an increase in the driving voltage when processing the organic compound layer of the light-emitting device by photolithography.,

[0081] In the intermediate layer having the configuration as described above, among the second organic compounds, particularly among the phenanthroline skeletons, an organic compound containing a 1,10-phenanthroline skeleton is preferable because the two nitrogen atoms it contains can coordinate to a metal, and thus an interaction with a metal or a metal compound is likely to occur.

[0082] When introducing an electron-donating group 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, and the interaction with a metal or a metal compound can be made more likely to occur.

[0083] The first layer may further contain an organic compound different from the second organic compound. The organic compound is preferably an organic compound having electron-transporting properties. In particular, the organic compound preferably has two or more heteroaromatic rings bonded or condensed to each other, and the two or more heteroaromatic rings preferably have a total of three or more heteroatoms. By the first layer containing such an organic compound, improvement in heat resistance, improvement in electron-transporting properties, etc. can be achieved.

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

[0085] Also, the second layer preferably further contains a substance exhibiting acceptor properties, and the 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, in particular, an organic compound having at least one of a halogen group and a cyano group is preferable, and an organic compound having at least one of fluorine and a cyano group is more preferable. Furthermore, it is more preferable that the total number of the halogen group (fluorine) and the cyano group contained in the organic compound is 4 or more. That is, the second layer is preferably a layer containing halogen, particularly fluorine.

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

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

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

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

[0090] Also, when the specific energy level of the LUMO level in the substance having electron-transporting properties used for the third layer 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 even more preferably -4.30 eV or more and -3.30 eV or less, it is preferable because an increase in the driving voltage can be suppressed. As the substance having electron-transporting properties used for the third layer, it is preferable to use a phthalocyanine-based material or a metal complex having a metal-oxygen bond and an aromatic ligand.

[0091] Also, the film 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 in order to suppress an increase in the driving voltage.

[0092] The light-emitting device of the present invention having the above-described configuration can be a light-emitting device with high current efficiency, low energy loss, and good characteristics. Further, in the display device according to one aspect of the present invention using such a light-emitting device, it is possible to obtain a display device with low power consumption, high reliability, capable of displaying at high brightness, and having good visibility.

[0093] Subsequently, a light-emitting device according to one aspect of the present invention will be described in detail with reference to the drawings. FIG. 1(A) shows a light-emitting device 130 according to one aspect of the present invention. The light-emitting device according to one aspect of the present invention includes a first light-emitting unit 501 including a first light-emitting layer 113_1 between a first electrode 101 including an anode and a second electrode 102 including a cathode, a second light-emitting layer 113_2, and a second light-emitting unit 502 including a second electron transport layer 114_2 (a laminate of a first electron transport layer 114_2a and a second electron transport layer 114_2b), and an intermediate layer 116, which is a tandem-type light-emitting device having an organic compound layer 103 (also referred to as an EL layer). Note that the first light-emitting unit may have 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 laminate structure of a first electron transport layer 114_2a and a second electron transport layer 114_2b. The second electron transport layer 114_2b is located between the first electron transport layer 114_2a and the cathode. The intermediate layer 116 has a second organic compound including a phenanthroline skeleton.

[0095] Note that it is preferable that the second electron transport layer 114_2b contains a first organic compound including a triazine skeleton in order to reduce power consumption. Further, it is preferable that the second electron transport layer 114_2b containing the first organic compound including a triazine skeleton is in contact with the second electrode 102 in order to reduce the driving voltage and power consumption by improving electron injectability.

[0096] In this embodiment, a light-emitting device having one intermediate layer 116 and two light-emitting units will be described as an example. However, a light-emitting device having n (n is an integer of 1 or more) layers of intermediate layers and n + 1 layers of light-emitting units may also be used. For example, the light-emitting device 130 shown in FIG. 1(B) is an example of a tandem-type light-emitting device with n = 2, which has 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] In addition to the layers such as the light-emitting layer and the electron transport layer described above, the first light-emitting unit 501 and the second light-emitting unit 502 may include other functional layers. In FIG. 1(A), in addition to the first light-emitting layer 113_1 and the first electron transport layer 114_1, the first light-emitting unit 501 is provided with a hole injection layer 111 and a first hole transport layer 112_1. In addition to the second light-emitting layer 113_2 and the second electron transport layer 114_2, the second light-emitting unit 502 is provided with a second hole transport layer 112_2. Although the configuration of the organic compound layer 103 in one aspect of the present invention is illustrated, the configuration of the organic compound layer 103 in one aspect of the present invention is not limited thereto, and any layer may not be provided, or other layers may be provided. Representative examples of other layers include a carrier blocking layer and an exciton blocking layer.

[0098] The first electrode 101 is an electrode including an anode. The first electrode 101 may have a laminated structure, and in that case, the layer in contact with the organic compound layer 103 functions as an anode. The anode is preferably formed using a metal, alloy, conductive compound, or a mixture thereof having a large work function (specifically, 4.0 eV or more). Specifically, for example, indium tin oxide (ITO), indium tin oxide containing silicon or silicon oxide, indium zinc oxide, indium oxide containing tungsten oxide and zinc oxide (IWZO), etc. can be mentioned. These conductive metal oxide films are usually formed by a sputtering method, but a sol-gel method or the like may be applied for production. As an example of the production method, indium zinc oxide can be formed by a sputtering method using a target in which 1 to 20 wt% of zinc oxide is added to indium oxide. Also, indium oxide containing tungsten oxide and zinc oxide (IWZO) can also be formed by a sputtering method using a target containing 0.5 to 5 wt% of tungsten oxide and 0.1 to 1 wt% of zinc oxide with respect to indium oxide. In addition to this, materials used for the anode include, 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. Or, graphene can also be used as a material for the anode. Note that by using the composite material constituting the second layer 117 in the intermediate layer 116 as a layer in contact with the anode (typically a hole injection layer), regardless of the work function, the electrode material can be selected.

[0099] The positive hole injection layer 111 is provided in contact with the anode and has a function of facilitating the injection of positive holes into the organic compound layer 103 (the first light-emitting unit 501). The positive hole injection layer 111 can be formed of a phthalocyanine-based compound or complex compound such as phthalocyanine (abbreviation: H2Pc), copper phthalocyanine (abbreviation: CuPc), an aromatic amine compound 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), or a polymer such as poly(3,4-ethylenedioxythiophene) / polystyrene sulfonic acid (abbreviation: PEDOT / PSS).

[0100] Further, the hole injection layer 111 may be formed of a substance having electron acceptor properties. As the substance having electron acceptor properties, an organic compound having an electron-withdrawing group (such as a halogen group or a cyano group) can be used. 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, and the like. In particular, a compound in which an electron-withdrawing group is bonded to a condensed aromatic ring having a plurality of heteroatoms, such as HAT-CN, is thermally stable and preferable. Further, a [3]radialene derivative having an electron-withdrawing group (particularly a halogen group such as a fluoro group or a cyano group) is preferable because of its very high electron accepting property. Specifically, α,α’,α’’-1,2,3-cyclopropanetriylidene tris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α’,α’’-1,2,3-cyclopropanetriylidene tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], α,α’,α’’-1,2,3-cyclopropanetriylidene tris[2,3,4,5,6-pentafluorobenzeneacetonitrile], and the like can be mentioned. As the substance having electron acceptor properties, in addition to the organic compounds described above, transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide can be used.In addition, a hole injection layer 111 can also be formed by phthalocyanine-based compounds or complex compounds such as phthalocyanine (abbreviation: H2Pc), copper phthalocyanine (abbreviation: CuPc), 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), or polymers such as poly(3,4-ethylenedioxythiophene) / polystyrenesulfonic acid (abbreviation: PEDOT / PSS). A substance having an acceptor property can extract electrons from an adjacent hole transport layer (or hole transport material) by applying an electric field.

[0101] Also, the hole injection layer 111 is preferably formed of a composite material containing the above-described material having an acceptor property and a substance having a hole transporting property.

[0102] As the substance having a hole transporting property used in the composite material, various organic compounds such as aromatic amine compounds, heteroaromatic compounds, aromatic hydrocarbons, and polymer compounds (oligomers, dendrimers, polymers, etc.) can be used. The substance having a hole transporting property used in the composite material is preferably a substance having a hole mobility of 1×10 -6 cm 2 / Vs or more. The substance having a hole transporting property used in the composite material is preferably a compound having a condensed aromatic hydrocarbon ring or a π-electron-excessive heteroaromatic ring. As the condensed aromatic hydrocarbon ring, an anthracene ring, a naphthalene ring, etc. are preferable. As the π-electron-excessive heteroaromatic ring, a condensed aromatic ring containing at least one of a pyrrole skeleton, a furan skeleton, and a thiophene skeleton in the ring is preferable, and specifically, a carbazole ring, a dibenzothiophene ring, or a ring in which an aromatic ring or a heteroaromatic ring is further condensed thereto is preferable.

[0103] Such a substance having hole transporting properties more preferably has any 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 having 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 such a substance having hole transporting properties is a substance having an N,N-bis(4-biphenyl)amino group, it is preferable because a light-emitting device with good lifetime can be fabricated.

[0104] Examples of substances having hole-transporting properties as described above include 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-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazol-9-yl)phenyl]tris(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-fluorene-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’-di(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-fluorene-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-fluorene-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9’-spirobi-9H-fluorene-1-amine, 9-[3-(triphenylsilyl)phenyl]-3,9’-bi-9H-carbazole (abbreviation: PSiCzCz), 9’-phenyl-9’H-9,3’:6’,Examples include 9’’-tercarbazole (abbreviation: PSiCzGI), etc.

[0105] In addition, as substances having hole-transporting properties, as other aromatic amine compounds, N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), etc. can also be used.

[0106] By forming the hole injection layer 111, the injectability of holes becomes good, and a light-emitting device with a small driving voltage can be obtained.

[0107] Among substances having acceptor properties, organic compounds having acceptor properties are easy to vaporize and easy to form films, so they are easy-to-use materials.

[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. As the organic compound having hole-transporting properties, it preferably has a hole mobility of 1×10 -6 cm 2 / Vs or more.

[0109] Examples of the substance having hole transporting property 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-phenylfluorene-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluorene-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'-di(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); 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviation: BisBPCz), 9,9'-bis(biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviation: BismBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H-3,3'-Bicarbazole (abbreviation: mBPCCBP), 9-(2-naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: βNCCP), 9-(3-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCmBP), 9-(4-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCBP), 9,9'-di-2-naphthyl-3,3'-9H,9'H-bicarbazole (abbreviation: BisβNCz), 9-(2-naphthyl)-9'-[1,1':4',1''-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-5'-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':4',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-phenyl-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviation: PCCzTp), 9,9'-bis(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(4-biphenyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(triphenylene-2-yl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-1-amine, 9-[3-(triphenylsilyl)phenyl]-3,9'-bi-9H-carbazole (abbreviation: PSiCzCz) and other compounds having a carbazole skeleton, 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,Compounds having a thiophene skeleton such as 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), compounds having a furan skeleton such as 4,4’,4’’-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II), 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II), etc. Among the above-mentioned ones, compounds having an aromatic amine skeleton and compounds having a carbazole skeleton are preferable because they have good reliability, high hole transportability, and contribute to reducing the driving voltage. Also, the organic compounds mentioned as substances having hole transportability used in the composite material of the hole injection layer 111 can be suitably used as materials constituting the hole transport layer. In addition, organic compounds in which the above-mentioned organic compounds are appropriately deuterated can also be used in the same manner.,

[0110] Note that the first hole transport layer 112_1 and the second hole transport layer 112_2 preferably have an organic compound containing the same skeleton, and more preferably have the same compound.,

[0111] The light-emitting layer (the first light-emitting layer 113_1, the second light-emitting layer 113_2) preferably has a light-emitting center substance and a host material. Note that the light-emitting layer may simultaneously contain other materials.,

[0112] Also, the first light-emitting layer 113_1 and the second light-emitting layer 113_2 are preferably light-emitting layers that exhibit light emission of a similar color. For example, in a display device, in order to express full color, red, green, and blue pixels are often used. In the case of a light-emitting device used for a red pixel, both the first light-emitting layer 113_1 and the second light-emitting layer 113_2 are light-emitting layers that exhibit red light emission. When used for a green pixel, both of the two light-emitting layers are light-emitting layers that exhibit green light emission. In the case of a blue pixel, both exhibit blue light emission. 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 in which the difference in the maximum peak wavelength in their emission spectra is 30 nm or less, more preferably compounds in which the difference is 20 nm or less, and even more preferably compounds in which the difference is 10 nm or less. It is more preferable that 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 the same.

[0113] The light-emitting center substance may be a fluorescent light-emitting substance, a phosphorescent light-emitting substance, a substance that exhibits thermally activated delayed fluorescence (TADF), or any other light-emitting substance.

[0114] In the light-emitting layer, examples of the fluorescent light-emitting substances that can be used as the light-emitting center substance include the following. Also, other fluorescent light-emitting substances can be used.

[0115] 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'-diphenylstilbene-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-carbazole-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-phenylenediamine) (abbreviation: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: 2PCAPPA), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), N,N,N',N',N'',N'',N''',N''' - octaphenyldibenzo[g,p]chrysene-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-carbazole-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-phenylanthracene-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracene-9-amine (abbreviation: DPhAPhA), Coumarin 545T, N,N’-diphenylquinacridone (abbreviation: DPQd), Rubrene, 5,12-bis(biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyran-4-ylidene)propanedinitrile (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM2), N,N,N’,N’-tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N’,N’-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2,6-Bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJTM), N,N'-diphenyl-N,N'-(1,6-pyrenediyl)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']bisbenzofuran-3,10-diamine (abbreviation: 3,10PCA2Nbf(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02), and the like. In particular, condensed aromatic diamine compounds typified by pyrene diamine compounds such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03 are preferable because they have high hole trapping properties and are excellent in luminous efficiency or reliability.,

[0116] In the light-emitting layer, examples of the phosphorescent material that can be used as the light-emitting center material include the following.,

[0117] Tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: [Ir(mpptz-dmp)3]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Mptz)3]), and other organometallic iridium complexes having a 4H-triazole skeleton, tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(Mptz1-mp)3]), tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Prptz1-Me)3]) and other organometallic iridium complexes having a 1H-triazole skeleton, fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpim)3]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me)3]), 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 having 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 having a benzimidazolide 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’ Organometallic iridium complexes having a phenylpyridine derivative having an electron-withdrawing group such as iridium(III) acetylacetonate (abbreviation: FIracac) as a ligand, (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-(4-tert-butyl-2-pyridinyl-κN)carbazole-2,1-diyl-κC1)platinum(II) (abbreviation: PtON-TBBI), and the like. These are compounds that exhibit blue phosphorescent emission and have an emission peak in the wavelength range from 450 nm to 520 nm. In addition, compounds in which some of the hydrogens of these compounds are deuterium can also be used.

[0118] Also, organometallic iridium complexes having a pyrimidine skeleton such as tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)3]), tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)3]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)2(acac)]), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)2(acac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm)2(acac)]), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(mpmppm)2(acac)]), (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2(acac)]), organometallic iridium complexes having a pyrazine skeleton such as (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-Me)2(acac)]), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-iPr)2(acac)]), tris(2-phenylpyridinato-N,C 2’ )iridium(III) (abbreviation: [Ir(ppy)3]), bis(2-phenylpyridinato-N,C 2’ )iridium(III) acetylacetonate (abbreviation: [Ir(ppy)2(acac)]), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: [Ir(bzq)2(acac)]), tris(benzo[h]quinolinato)iridium(III) (abbreviation: [Ir(bzq)3]), tris(2-phenylquinolinato-N,C 2’ )iridium(III) (abbreviation: [Ir(pq)3]), bis(2-phenylquinolinato-N,C 2’)Iridium(III) acetylacetonate (abbreviation: [Ir(pq)2(acac)]), [2-d3-methyl-8-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) (abbreviation: Ir(5mppy-d3)2(mbfpypy-d3)), {2-(methyl-d3)-8-[4-(1-methylethyl-1-d)-2-pyridinyl-κN]benzofuro[2,3-b]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-κN2)phenyl-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) (abbreviation: [Ir(5mppy-d3)2(mdppy-d3)]), [2-methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy)2(mbfpypy)]), [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium (abbreviation: [Ir(ppy)2(mdppy)]), tris{2-[5-(methyl-d3)-4-phenyl-2-pyridinyl-κN]phenyl-κC}iridium(III) (abbreviation: Ir(5m4dppy-d3)3) and other organometallic iridium complexes having a pyridine skeleton, and rare earth metal complexes such as tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: [Tb(acac)3(Phen)]).These are mainly compounds that exhibit green phosphorescence and have a peak of luminescence in the wavelength range from 500 nm to 600 nm. Note that an organometallic iridium complex having a pyrimidine skeleton is particularly preferred because it is also remarkably excellent in reliability or luminescence efficiency. Further, compounds in which a part of the hydrogen atoms these compounds have are deuterium can also be used.

[0119] In addition, organometallic iridium complexes having a pyrimidine skeleton such as (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(5mdppm)2(dpm)]), bis[4,6-di(naphthalen-1-yl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(d1npm)2(dpm)]), (acetylacetonato)bis(2,3,5-triphenylpyrazinato)iridium(III) (abbreviation: [Ir(tppr)2(acac)]), bis(2,3,5-triphenylpyrazinato)(dipivaloylmethanato)iridium(III) (abbreviation: [Ir(tppr)2(dpm)]), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq)2(acac)]), organometallic iridium complexes having a pyrazine skeleton, tris(1-phenylisoquinolinato-N,C 2’ )iridium(III) (abbreviation: [Ir(piq)3]), bis(1-phenylisoquinolinato-N,C 2’)In addition to organometallic iridium complexes having 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), and (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 platinum(II) 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin (abbreviation: PtOEP), and rare earth metal complexes such as tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: [Eu(DBM)3(Phen)]) and tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: [Eu(TTA)3(Phen)]) are also included. These are compounds that exhibit red phosphorescent emission and have an emission peak in the wavelength range from 600 nm to 700 nm. In addition, organometallic iridium complexes having a pyrazine skeleton can obtain red emission with good chromaticity. Compounds in which part of the hydrogen of these compounds is deuterium can also be used.

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

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

[0122] As the TADF material, fullerenes and their derivatives, acridines and their derivatives, eosin derivatives, etc. can be used. Also, metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd), etc. can be mentioned. Examples of the metal-containing porphyrins include 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)), octaethylporphyrin-platinum chloride complex (PtCl2OEP), etc. shown in the following structural formulas.

[0123] [Chemical formula]

[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-dihydroacridine)phenyl]sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10’H-spiro[acridine-9,9’-anthracene]-10’-one (abbreviation: ACRSA), etc., heterocyclic compounds having one or both of a π-electron-excessive heterocyclic aromatic ring and a π-electron-deficient heterocyclic aromatic ring can also be used. Since the heterocyclic compound has a π-electron-excessive heterocyclic aromatic ring and a π-electron-deficient heterocyclic aromatic ring, it has both high electron transportability and hole transportability, which is preferable. Among them, among the skeletons having a π-electron-deficient heterocyclic aromatic ring, a pyridine skeleton, a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), and a triazine skeleton are preferable because they are stable and have good reliability. In particular, a benzofuropyrimidine skeleton, a benzothienopyrimidine skeleton, a benzofuropyrazine skeleton, and a benzothienopyrazine skeleton are preferable because they have high acceptor properties and good reliability. Also, among the skeletons having a π-electron-excessive heterocyclic aromatic 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 preferable to have at least one of these skeletons.Note that as the furan skeleton, a dibenzofuran skeleton is preferred, and as the thiophene skeleton, a dibenzothiophene skeleton is preferred. Further, 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 preferred. Note that a substance in which a π-electron excess type heteroaromatic ring and a π-electron deficient type heteroaromatic ring are directly bonded has both the electron donating property of the π-electron excess type heteroaromatic ring and the electron accepting property of the π-electron deficient type heteroaromatic ring enhanced, and the energy difference between the S1 level and the T1 level becomes small. Therefore, it is particularly preferred because thermally activated delayed fluorescence can be efficiently obtained. Note that instead of the π-electron deficient type heteroaromatic ring, an aromatic ring to which an electron withdrawing group such as a cyano group is bonded may be used. Further, as the π-electron excess type skeleton, an aromatic amine skeleton, a phenazine skeleton, etc. can be used. Further, as the π-electron deficient type skeleton, a 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 borantrene, an aromatic ring having a nitrile group or a cyano group such as benzonitrile or cyanobenzene, a heteroaromatic ring, a carbonyl skeleton such as benzophenone, a phosphine oxide skeleton, a sulfone skeleton, etc. can be used. Thus, a π-electron deficient type skeleton and a π-electron excess type skeleton can be used instead of at least one of the π-electron deficient type heteroaromatic ring and the π-electron excess type heteroaromatic ring.

[0125]

Chemical formula

[0126] Further, as the TADF material, a TADF material in which the singlet excited state and the triplet excited state are in a thermal equilibrium state may be used. Since the emission lifetime (excitation lifetime) of such a TADF material is short, a decrease in efficiency in a high brightness region in the light emitting device can be suppressed. Specifically, materials having a molecular structure shown below can be mentioned.

[0127]

Chemical formula

[0128] Note that a TADF material is a material having a function of converting energy from triplet excitation energy to singlet excitation energy by reverse intersystem crossing because the difference between the S1 level and the T1 level is small. Therefore, up-conversion (reverse intersystem crossing) from triplet excitation energy to singlet excitation energy is possible with a small amount of thermal energy, and a singlet excited state can be efficiently generated. In addition, triplet excitation energy can be converted into light emission.

[0129] In addition, an exciplex (also referred to as an exciplex, exiplex, or exciplex) that forms an excited state with two types of substances has a function as a TADF material in which the difference between the S1 level and the T1 level is extremely small and triplet excitation energy can be converted into singlet excitation energy.

[0130] Note that as an index of the T1 level, a phosphorescence spectrum observed at low temperature (for example, from 77 K to 10 K) may be used. As a TADF material, when a tangent is drawn at the trailing edge on the short wavelength side of its fluorescence spectrum and the energy of the wavelength of the extrapolated line is taken as the S1 level, and a tangent is drawn at the trailing edge on the short wavelength side of the phosphorescence spectrum and the energy of the wavelength of the extrapolated line is taken as the T1 level, it is preferable that 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 a light-emitting substance, it is preferable that the S1 level of the host material is higher than the S1 level of the TADF material. Also, it is preferable that the T1 level of the host material is higher than the T1 level of the TADF material.

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

[0133] As materials having hole-transporting properties, organic compounds having an amine skeleton, a π-electron-excessive heteroaromatic ring skeleton, etc. are preferable. As the π-electron-excessive heteroaromatic ring, a condensed 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 in the ring is preferable. Specifically, a carbazole ring, a dibenzothiophene ring, or a ring in which an aromatic ring or a heteroaromatic ring is further condensed thereto is preferable.

[0134] As such a substance having hole-transporting properties, it is more preferable to have 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 having 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. In addition, when these substances having hole-transporting properties are an organic compound having an N,N-bis(4-biphenyl)amino group, it is preferable because a light-emitting device with good lifetime can be fabricated.

[0135] As such organic compounds, for example, the following organic compounds are preferable. 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-phenylfluorene-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluorene-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'-di(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), etc. compounds having an aromatic amine skeleton, 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 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'-bi-9H-carbazole (abbreviation: PSiCzCz), 9'-phenyl-9'H-9,3':6',Compounds having a carbazole skeleton such as 9’’-tercarbazole (abbreviation: PSiCzGI), 4,4’,4’’-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV) and other compounds having a thiophene skeleton, 4,4’,4’’-(benzene-1,3,5-triyl)tri(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 can be mentioned. Among the above, compounds having an aromatic amine skeleton or a carbazole skeleton are preferable because they have good reliability, high hole transportability, and contribute to reducing the driving voltage. In addition, the organic compounds exemplified as materials having hole transportability in the hole transport layer can also be used.,

[0136] As the material having electron transporting property, an organic compound having a π-electron deficient heteroaromatic ring is preferable. Examples of the organic compound having a π-electron deficient heteroaromatic ring skeleton include organic compounds containing a heteroaromatic ring having an azole skeleton, organic compounds containing a heteroaromatic ring having a pyridine skeleton, organic compounds containing a heteroaromatic ring having a diazine skeleton, and organic compounds containing a heteroaromatic ring having a triazine skeleton.

[0137] Among them, an organic compound containing a heteroaromatic ring having a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton) or an organic compound containing a heteroaromatic ring having a pyridine skeleton, and an organic compound containing a heteroaromatic ring having a triazine skeleton are preferable because of their good reliability. 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 transport properties and contribute to reducing the driving voltage. Further, a benzofuropyrimidine skeleton, a benzothienopyrimidine skeleton, a benzofuropyrazine skeleton, and a benzothienopyrazine skeleton are preferable because of their high acceptor properties and good reliability.

[0138] Examples of the organic compound having a π-electron deficient heteroaromatic ring skeleton include, for example, the following organic compounds. 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), organic compounds having an azole skeleton such as 4,4’-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs), 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), bathophenanthroline (abbreviation: Bphen), bathocuproine (abbreviation: BCP), 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2’-(1,3-Phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), 2-[3-(2-Triphenylenyl)phenyl]-1,10-phenanthroline (abbreviation: mTpPPhen), 2-phenyl-9-(2-triphenylenyl)-1,10-phenanthroline (abbreviation: Ph-TpPhen), 2-[4-(9-Phenanthrenyl)-1-naphthalenyl]-1,10-phenanthroline (abbreviation: PnNPhen), 2-[4-(2-Triphenylenyl)phenyl]-1,10-phenanthroline (abbreviation: pTpPPhen), and other organic compounds containing a heteroaromatic ring 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]dibenzof[h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3’-(9H-Carbazol-9-yl)biphenyl-3-yl]dibenzof[h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4’-(9-Phenyl-9H-carbazol-3-yl)-3,1’-biphenyl-1-yl]dibenzof[h]quinoxaline (abbreviation: 2mpPCBPDBq), 2-[4-(3,6-Diphenyl-9H-carbazol-9-yl)phenyl]dibenzof[h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(Dibenzothiophen-4-yl)phenyl]dibenzof[h]quinoxaline (abbreviation: 7mDBTPDBq-II), and 6-[3-(Dibenzothiophen-4-yl)phenyl]dibenzof[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-(2-naphthyl)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-(3-pyridyl)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 having 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 - triazine - 2 - yl)phenyl]-9’ - phenyl - 2,3’ - bi - 9H - carbazole (abbreviation: mPCCzPTzn - 02), 2 - [3’ - (9,9 - dimethyl - 9H - fluorene - 2 - yl)biphenyl - 3 - yl]-4,6 - diphenyl - 1,3,5 - triazine (abbreviation: mFBPTzn), 5 - [3 - (4,6 - diphenyl - 1,3,5 - triazine - 2 - yl)phenyl]-7,7 - dimethyl - 5H,7H - indeno[2,1 - b]carbazole (abbreviation: mINc(II)PTzn), 2 - {3 - [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 - pyridinyl)-5 - (9 - phenanthrenyl)phenyl]-4,6 - diphenyl - 1,3,5 - triazine (abbreviation: mPn - mDMePyPTzn), 11 - [4 - (biphenyl - 4 - yl)-6 - phenyl - 1,3,5 - triazine - 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 - triazine - 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 - naphthalenyl)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 - 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), and other organic compounds containing a heteroaromatic ring having a triazine skeleton. Further, an organic compound containing a heteroaromatic ring having a diazine skeleton or an organic compound containing a heteroaromatic ring having a pyridine skeleton, and an organic compound containing a heteroaromatic ring having a triazine skeleton are preferred because of their good reliability. 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 transport properties and contribute to reducing the driving voltage.,

[0139] As the TADF material that can be used as the host material, those listed as the TADF materials that can be used as the light-emitting center substance can be used in the same manner. When the TADF material is used as the host material, the triplet excitation energy generated in the TADF material is converted into singlet excitation energy by reverse intersystem crossing, and further, by energy transfer to the light-emitting substance, the luminous efficiency of the light-emitting device can be enhanced. At this time, the TADF material functions as an energy donor, and the light-emitting substance functions as an energy acceptor.

[0140] This is very effective when the above-mentioned light-emitting substance is a fluorescent light-emitting substance. Also, at this time, in order to obtain high luminous efficiency, it is preferable that the S1 level of the TADF material is higher than the S1 level of the fluorescent light-emitting substance. Also, it is preferable that the T1 level of the TADF material is higher than the S1 level of the fluorescent light-emitting substance. Therefore, it is preferable that the T1 level of the TADF material is higher than the T1 level of the fluorescent light-emitting substance.

[0141] Also, it is preferable to use a TADF material that exhibits light emission overlapping with the wavelength of the absorption band on the lowest energy side of the fluorescent light-emitting substance. By doing so, the transfer of excitation energy from the TADF material to the fluorescent light-emitting substance becomes smooth, and light emission can be obtained efficiently, which is preferable.

[0142] In addition, in order to efficiently generate singlet excited energy from triplet excited energy through reverse intersystem crossing, it is preferable that carrier recombination occurs in the TADF material. Further, it is preferable that the triplet excited energy generated in the TADF material does not transfer to the triplet excited energy of the fluorescent substance. For this purpose, it is preferable that the fluorescent substance has a protecting group around the lumophore (skeleton responsible for luminescence) of the fluorescent substance. As the protecting group, a substituent having no π bond is preferable, a saturated hydrocarbon is preferable, and specifically, an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a trialkylsilyl group having 3 to 10 carbon atoms can be mentioned. It is more preferable that there are a plurality of protecting groups. Since a substituent having no π bond has poor function of transporting carriers, it is possible to increase the distance between the TADF material and the lumophore of the fluorescent substance with little influence on carrier transport or carrier recombination. Here, the lumophore refers to an atomic group (skeleton) responsible for luminescence in the fluorescent substance. The lumophore preferably has a skeleton having a π bond, preferably contains an aromatic ring, and preferably has a condensed aromatic ring or a condensed heteroaromatic ring. Examples of such lumophores include 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 chrysene skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, a naphthobisbenzofuran skeleton, and the like. In particular, fluorescent substances having a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, a chrysene skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, or a naphthobisbenzofuran skeleton are preferable because they have a high fluorescence quantum yield.

[0143] When using a fluorescent luminescent substance as a luminescence center substance, as the host material, a material having an anthracene skeleton is suitable. When a substance having an anthracene skeleton is used as the host material of the fluorescent luminescent substance, it is possible to realize a luminescent layer with both good luminous efficiency and durability. As the substance having an anthracene skeleton used as the host material, a substance having a diphenylanthracene skeleton, particularly a substance having a 9,10-diphenylanthracene skeleton, is preferable because it is chemically stable. Further, when the host material has a carbazole skeleton, it is preferable because the hole injection and transport properties are enhanced. However, when it contains a benzocarbazole skeleton in which a benzene ring is further condensed with carbazole, the HOMO is about 0.1 eV higher than that of the carbazole skeleton, and holes are more likely to enter, so it is more preferable. In particular, when the host material contains a dibenzocarbazole skeleton, the HOMO is about 0.1 eV higher than that of the carbazole skeleton, holes are more likely to enter, the hole transport property is excellent, and the heat resistance is also high, so it is suitable. Therefore, a substance having both a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzocarbazole skeleton or a dibenzocarbazole skeleton) is more preferable as the host material. From the above viewpoint of hole injection and transport properties, a benzofluorene skeleton or a dibenzofluorene skeleton may 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-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]benzo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10-[4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4'-yl]anthracene (abbreviation: FLPPA), 9-(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-anthracenyl)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-anthracenyl]phenyl}-2-ethyl-1H-benzimidazole (abbreviation: EtBImPBPhA), and the like. In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA exhibit very good properties and are thus preferred choices.

[0144] Note that the host material may be a material obtained by mixing a plurality of substances. When using a mixed host material, it is preferable to mix a material having electron transporting properties and a material having hole transporting properties. By mixing a material having electron transporting properties and a material having hole transporting properties, the transporting properties of the light emitting layer (the first light emitting layer 113_1 and the second light emitting layer 113_2) can be easily adjusted, and the control of the recombination region can also be easily performed. The weight ratio of the content of the material having hole transporting properties to the material having electron transporting properties may be such that the material having hole transporting properties: the material having electron transporting properties = 1:19 to 19:1.

[0145] Note that, as a part of the above mixed material, a phosphorescent substance can be used. The phosphorescent substance can be used as an energy donor that supplies excitation energy to the fluorescent substance when using the fluorescent substance as the light emitting substance.

[0146] Further, an exciplex may be formed between these mixed materials. By selecting a combination that forms an exciplex that emits light overlapping the wavelength of the absorption band on the lowest energy side of the light emitting substance, energy transfer becomes smooth and light emission can be obtained efficiently, which is preferable. Also, since the driving voltage is reduced by using this configuration, it is preferable.

[0147] Note that at least one of the materials forming the exciplex may be a phosphorescent substance. By doing so, the triplet excitation energy can be efficiently converted into singlet excitation energy by reverse intersystem crossing.

[0148] As a combination of materials that efficiently form an exciplex, it is preferable that the HOMO level of the material having hole transporting properties is equal to or higher than the HOMO level of the material having electron transporting properties. Also, it is preferable that the LUMO level of the material having hole transporting properties is equal to or higher than the LUMO level of the material having electron transporting properties. Note that the LUMO level and HOMO level of the material can be derived from the electrochemical characteristics (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV) measurement.

[0149] Note that the formation of the exciplex can be confirmed, for example, by comparing the emission spectra of a material having hole-transporting properties, the emission spectrum of a material having electron-transporting properties, and the emission spectrum of a mixed film obtained by mixing these materials, and observing that the emission spectrum of the mixed film is shifted to a longer wavelength (or has a new peak on the longer wavelength side) than the emission spectra of the respective materials. Alternatively, the transient photoluminescence (PL) of a material having hole-transporting properties, the transient PL of a material having electron-transporting properties, and the transient PL of a mixed film obtained by mixing these materials are compared, and the difference in transient response such that the transient PL lifetime of the mixed film has a longer-lived component or the ratio of the delayed component becomes larger than the transient PL lifetimes of the respective materials is observed to confirm the formation of the exciplex. Further, the above transient PL may be read as transient electroluminescence (EL). That is, the transient EL of a material having hole-transporting properties, the transient EL of a material having electron-transporting properties, and the transient EL of a mixed film thereof are compared, and the formation of the exciplex can also be confirmed by observing the difference in transient response.

[0150] The first electron transport layer 114_1 and the second electron transport layer 114_2 can be made of a substance having higher electron-transporting properties than hole-transporting properties, and are layers containing a substance having electron-transporting properties. As the material having electron-transporting properties, a substance having an electron mobility with the square root of the electric field strength [V / cm] at 600 being 1×10 -7 cm 2 / Vs or more, preferably 1×10 -6 cm 2 / Vs or more is preferable. Note that as the above organic compound, an organic compound having a π-electron-deficient heteroaromatic ring is preferable. As the organic compound having a π-electron-deficient heteroaromatic ring, for example, it is preferably any one or more of an organic compound containing a heteroaromatic ring having an azole 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.

[0151] As the organic compound having electron transporting properties that can be used for the first electron transporting layer 114_1 and the second electron transporting layer 114_2, the organic compound that can be used as the organic compound having electron transporting properties of the host material in the first light emitting layer 113_1 and the second light emitting layer 113_2 can be similarly used. Among them, an organic compound containing a heteroaromatic ring having a diazine skeleton or an organic compound containing a heteroaromatic ring having a pyridine skeleton, and an organic compound containing a heteroaromatic ring having a triazine skeleton are preferable because of their good reliability. 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 properties and contribute to reducing the driving voltage.

[0152] Note that the first electron transporting layer 114_1 may or may not have a laminated structure. However, having a laminated structure enables providing a light emitting device with high current efficiency, lower power consumption, and good characteristics. When it has a single layer structure, it is advantageous from the viewpoint of manufacturing cost because fewer film formation chambers are required. When it has a laminated structure, among the layers included in the laminated structure, the layer located on the intermediate layer side is preferably a layer containing a third organic compound containing a triazine skeleton for reducing the driving voltage and power consumption, and is preferably a layer containing a fourth organic compound not containing a triazine skeleton because the electron transporting property from the intermediate layer can be appropriately controlled.

[0153] As described above, the second electron transporting layer 114_2 has a laminated structure. In FIG. 1(A), the second electron transporting layer 114_2 shows a configuration having a laminated structure of a second a electron transporting layer 114_2a and a second b electron transporting layer 114_2b. The second b electron transporting layer 114_2b is located between the second a electron transporting layer 114_2a and the cathode. It is preferable that the second b electron transporting layer 114_2b is in contact with the second electrode 102 for reducing the driving voltage and power consumption due to the improvement of electron injectability.

[0154] Incidentally, the second electron transport layer 114_2b preferably contains a first organic compound including a triazine skeleton. Also, as described above, the second electron transport layer 114_2b is preferably in contact with the second electrode 102. However, it is more preferable that the second electron transport layer 114_2b containing the first organic compound including a triazine skeleton is in contact with the second electrode 102 for reducing the driving voltage and power consumption due to the improvement of electron injectability. Details have already been described, so they will be omitted.

[0155] Incidentally, it is preferable that the first electron transport layer 114_1 has an organic compound including a triazine skeleton for reducing power consumption. In particular, it is preferable that the organic compound including a triazine skeleton contained in the first electron transport layer 114_1 is the same organic compound as the first organic compound including a triazine skeleton contained in the second electron transport layer 114_2b, because it suppresses the complication of the manufacturing apparatus and is also advantageous in terms of raw material procurement cost. When the first electron transport layer 114_1 has a laminated structure, it is preferable that the layer in contact with the intermediate layer 116 contains an organic compound including a triazine skeleton.

[0156] Also, when the first electron transport layer 114_1 has a laminated structure, by having an organic compound not including a triazine skeleton in the layer in contact with the intermediate layer 116, it becomes easy to control the carrier transport property, and it becomes possible to provide a light-emitting device with good characteristics. As the organic compound not including a triazine skeleton, an organic compound including a heteroaromatic ring having a pyridine skeleton, and an organic compound including a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton are preferable. Also, as the organic compound not including a triazine skeleton, it is preferable that it is an organic compound having at least one of a pyrimidine skeleton, an imidazole skeleton, and an anthracene skeleton. For example, using an organic compound having a pyrimidine skeleton and an anthracene skeleton, or an organic compound having an imidazole skeleton and an anthracene skeleton is preferable because it becomes easier to control the carrier transport property.

[0157] The intermediate layer 116 is a layer containing a second organic compound including a phenanthroline skeleton. As shown in Fig. 1(A), the intermediate layer 116 preferably has a first layer 119 containing a second organic compound including a phenanthroline skeleton. Further, the intermediate layer 116 preferably has a fifth organic compound having hole transporting properties and a second layer 117 containing a substance having acceptor properties. Note that the second layer 117 is located closer to the second electrode 102 than the first layer 119. The intermediate layer 116 may have a third layer 118 between the first layer 119 and the second layer 117.

[0158] Since the details of the first layer have been described above, repetitive description is omitted.

[0159] Note that the first layer 119 may further contain an organic compound having electron transporting properties. As the organic compound having electron transporting properties that can be used for the organic compound, the organic compounds that can be used as the organic compounds having electron transporting properties of the host materials in the first light-emitting layer 113_1 and the second light-emitting layer 113_2 can be used in the same manner. Further, as the organic compound, an organic compound having two or more heteroaromatic rings bonded or condensed to each other, and the two or more heteroaromatic rings having a total of three or more heteroatoms is preferably used because the resistance to the photolithography method is improved and an increase in driving voltage can be suppressed.

[0160] Note that the first layer 119 may have a laminated structure of 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. However, the mixed layer is preferable because the number of deposition chambers is small and the manufacturing cost can be reduced, and it also contributes to improving the stability of the light-emitting device.

[0161] When an organic compound is mixed with a metal or a metal compound, when analyzing the first layer 119 in the film thickness direction, the distribution of the organic compound and the distribution of the metal or the metal compound generally show the same tendency. That is, when the distribution of the organic compound is constant, the distribution of the metal or the metal compound is also generally constant. In the case of a laminated structure of a layer containing an organic compound and a layer having a metal or a metal compound, although the metal or the metal compound may be detected in a region other than the layer due to diffusion from the layer having the metal or the metal compound, since it shows a distribution different from the distribution of the organic compound, the analysis results can be separated into diffusion and mixing.

[0162] The second layer 117 preferably contains a fifth organic compound having hole transporting properties. Further, the second layer 117 preferably further contains a substance showing acceptor properties, and the substance showing acceptor properties is preferably an organic compound showing acceptor properties to the fifth organic compound.

[0163] When the second layer 117 is a layer containing a fifth organic compound and a substance showing acceptor properties 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. Thereby, the light emitting device 130 of one aspect 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. Note that as the fifth organic compound, 1×10 -6 cm 2It is preferably an organic compound having a hole mobility of 0.1 cm2 / Vs or more. Further, the fifth organic compound is preferably a compound having a condensed aromatic hydrocarbon ring or a π-electron-excessive heteroaromatic ring. As the condensed aromatic hydrocarbon ring, an anthracene ring, a naphthalene ring, etc. are preferable. Further, as the π-electron-excessive 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 an aromatic ring or a heteroaromatic ring is further condensed thereto is preferable.

[0165] As such an organic compound having hole transport properties, it is more preferable to have any 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 having 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. In addition, it is preferable that these organic compounds having hole transport properties are substances having an N,N-bis(4-biphenyl)amino group because a light-emitting device with good lifetime can be fabricated.

[0166] As the organic compound having hole transport properties as described above, specifically, the organic compounds listed as the organic compounds having hole transport properties that can be used for the hole injection layer 111 can be used in the same manner.

[0167] As the substance having acceptor properties, for example, the substances listed as the organic compounds having acceptor properties that can be used for the hole injection layer 111 can be similarly used. In particular, an organic compound having at least one of a halogen group and a cyano group is preferable, and an organic compound having at least one of fluorine and a cyano group is more preferable. Further, it is more preferable that the total number of the halogen group (fluorine) and the cyano group contained in the organic compound is 4 or more. Examples of the organic compound having at least one of a halogen group and a cyano group include α,α’,α’’-1,2,3-cyclopropanetriylidene tris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α’,α’’-1,2,3-cyclopropanetriylidene tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], α,α’,α’’-1,2,3-cyclopropanetriylidene tris[2,3,4,5,6-pentafluorobenzeneacetonitrile], and the like.

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

[0169] The third layer 118 contains a substance having electron transporting properties, prevents the interaction between the first layer 119 and the second layer 117, smoothes the transfer of electrons to reduce the driving voltage, and has functions such as reducing the interaction between the first layer 119 and the second layer 117 and improving reliability.

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

[0171] Also, the specific energy level of the LUMO level in the substance having electron transporting properties used for the third layer 118 is preferably -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 even more preferably -4.30 eV or more and -3.30 eV or less, which can suppress the increase in the driving voltage and is preferable. As the substance having electron transporting properties used for the third layer 118, it is preferable to use a phthalocyanine-based material or a metal complex having a metal-oxygen bond and an aromatic ligand.

[0172] As the substance having electron transporting properties used for the third layer 118, specifically, quinoxalino[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), perylene tetracarboxylic acid derivatives such as 3,4,9,10-perylenetetracarboxyl-bis-benzimidazole (abbreviation: PTCBI), (C60-Ih)[5,6]fullerene (abbreviation: C60), (C70-D5h)[5,6]fullerene (abbreviation: C70) can be used. Further, a compound having a heterophane skeleton which is a cyclophane skeleton containing a heterocycle can be used, and as the compound, for example, phthalocyanine compounds such as phthalocyanine (abbreviation: H2Pc) can be used. Also, 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., metal phthalocyanines having copper, zinc, cobalt, iron, chromium, nickel, etc., and their derivatives, etc. can be used. In particular, phthalocyanine-based 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 preferable.

[0173] Further, 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] Since the second layer 117 in the intermediate layer 116 functions as a hole injection layer, the second light emitting unit 502 does not have a hole injection layer, but a hole injection layer may be provided in the second light emitting unit 502.

[0175] The second electrode 102 is an electrode including a cathode. The second electrode 102 may have a laminated structure. In that case, the layer in contact with the organic compound layer 103 functions as a cathode. As the material for forming the cathode, a metal, alloy, electrically conductive compound, or a mixture 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), strontium (Sr), and alloys containing these (MgAg, AlLi), rare earth metals such as europium (Eu), ytterbium (Yb), and alloys containing these. Specifically, for example, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), 8-hydroxyquinolinato-lithium (abbreviation: Liq), alkali metals, alkaline earth metals, rare earth elements or their compounds or complexes such as ytterbium (Yb), or electrides can be mentioned. Examples of electrides include substances obtained by adding electrons in high concentration to a mixed oxide of calcium and aluminum. Note that two or more of these may be mixed and used. When the second electrode 102 has a laminated structure, materials with good conductivity can be used for layers other than the cathode regardless of the work function.

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

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

[0178] These conductive materials can be formed into a film using dry methods such as vacuum evaporation or sputtering, inkjet methods, spin coating methods, etc. Alternatively, they may be formed by a wet method using the sol-gel method, or may be formed by a wet method using a paste of a metal material.

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

[0180] Also, the above-described respective electrodes or respective layers may be formed using different film-forming methods.

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

[0182] The light-emitting device 130a has an organic compound layer 103a between a first electrode 101a and a second electrode 102 on an insulating layer 175. 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. Although FIG. 2 shows an example in which two light-emitting units are stacked, a configuration in which three or more light-emitting units are stacked may also be used. The first light-emitting unit 501a has 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 (a first a electron transport layer 114a_1a, a first b electron transport layer 114a_1b). Although the first electron transport layer 114a_1 is shown as a stacked structure, it may be a single-layer structure. The intermediate layer 116a has a second layer 117a, a third layer 118a, and a first layer 119a. The third layer 118a may or may not be present. The second light-emitting unit 502a has a second hole transport layer 112a_2, a second light-emitting layer 113a_2, and a second electron transport layer 114a_2 (a second a electron transport layer 114a_2a, a second b electron transport layer 114a_2b).

[0183] The light-emitting device 130b has an organic compound layer 103b between a first electrode 101b and a second electrode 102 on an 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 laminated with an intermediate layer 116b therebetween. Although FIG. 2 shows an example in which two light-emitting units are laminated, a structure in which three or more light-emitting units are laminated may also be used. The first light-emitting unit 501b has 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 (a first a electron transport layer 114b_1a and a first b electron transport layer 114b_1b). Although the first electron transport layer 114b_1 is shown as a laminated structure, it may be a single-layer structure. The intermediate layer 116b has a second layer 117b, a third layer 118b, and a first layer 119b. The third layer 118b may or may not be present. The second light-emitting unit 502b has a second hole transport layer 112b_2, a second light-emitting layer 113b_2, and a second electron transport layer 114b_2 (a second b electron transport layer 114b_2a and a second b electron transport layer 114b_2b).

[0184] Both the second electron transport layer 114a_2 and the second electron transport layer 114b_2 have a laminated structure. Further, among the laminated structures, the layers located on the cathode side, the second b electron transport layer 114a_2b and the second b 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 containing 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 exhibit light emission of a similar color. Further, the light-emitting center substances contained in each other are preferably compounds in which the difference in the maximum peak wavelength in their emission spectra is 30 nm or less, more preferably compounds in which the difference is 20 nm or less, still more preferably compounds in which the difference is 10 nm or less, and it is even more preferable that the contained light-emitting center substances are the same. The first light-emitting layer 113b_1 and the second light-emitting layer 113b_2 are preferably light-emitting layers that exhibit light emission of a similar color. Further, the light-emitting center substances contained in each other are preferably compounds in which the difference in the maximum peak wavelength in their emission spectra is 30 nm or less, more preferably compounds in which the difference is 20 nm or less, still more preferably compounds in which the difference is 10 nm or less, and it is even more preferable that the contained light-emitting center substances are the same.

[0186] Also, it is preferable that the first light-emitting layer 113a_1 and the first light-emitting layer 113b_1 are separated from each other, and the second light-emitting layer 113a_2 and the second light-emitting layer 113b_2 are separated from each other. Further, it is preferable that the first light-emitting layer 113a_1 and the first light-emitting layer 113b_1 are different light-emitting layers from each other, and the second light-emitting layer 113a_2 and the second light-emitting layer 113b_2 are different light-emitting layers from each other. Also, it is preferable that the emission colors of the first light-emitting layer 113a_1 and the second light-emitting layer 113a_2 are different from the emission colors of the first light-emitting layer 113b_1 and the second light-emitting layer 113b_2. Further, it is preferable that the light-emitting center substance contained in the first light-emitting layer 113a_1 and the light-emitting center substance contained in the first light-emitting layer 113b_1 are different substances, and the light-emitting center substance contained in the second light-emitting layer 113a_2 and the light-emitting center substance contained in the second light-emitting layer 113b_2 are different substances.

[0187] The light-emitting center substance contained in the first light-emitting layer 113a_1 and the light-emitting center substance contained in the first light-emitting layer 113b_1 are different substances, and the light-emitting center substance contained in the second light-emitting layer 113a_2 and the light-emitting center substance contained in the second light-emitting layer 113b_2 are different substances (for example, when 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, or when 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 when 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 device 130a and the light-emitting device 130b is different for each. Therefore, usually, in order to extract the performance of each of the light-emitting device 130a and the light-emitting device 130b, an appropriate intermediate layer and electron transport layer must be selected and changed for each. However, by applying a layer having a first organic compound containing a triazine skeleton to the second electron transport layer 114a_2 and the second electron transport layer 114b_2, and applying a layer containing a second organic compound containing a phenanthroline skeleton to 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 configuration, the performance can be extracted for both the light-emitting device 130a and the light-emitting device 130b. That is, both productivity improvement and performance improvement can be satisfied. Note that the first layer 119a and the first layer 119b may have the same configuration.

[0188] Note that 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 a electron transport layer 114a_1a and the first a electron transport layer 114b_1a, the first b electron transport layer 114a_1b and the first b 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 a electron transport layer 114a_2a and the second a electron transport layer 114b_2a, the second b electron transport layer 114a_2b and the second b electron transport layer 114b_2b) may each be a continuous layer, or may be independently separated in the light-emitting device 130a and the light-emitting device 130b. By being a continuous layer, productivity is improved and a light-emitting device can be manufactured at low cost. By being layers separated for each light-emitting device, materials suitable for the emission color can be used, and a light-emitting device or display device with good characteristics can be manufactured. In particular, since the second b electron transport layer 114a_2b and the second b electron transport layer 114b_2b are a continuous layer, it is preferable because both the light-emitting device 130a and the light-emitting device 130b can be made into light-emitting devices having good characteristics.

[0189] Saying that it is a continuous layer means that the 2b-th electron transport layer 114a_2b and the 2b-th electron transport layer 114b_2b are layers made of the same material. That is, by the 2b-th electron transport layer 114a_2b and the 2b-th electron transport layer 114b_2b being layers made of the same material, both the light-emitting device 130a and the light-emitting device 130b can be made into light-emitting devices having good characteristics. Further, it is more preferable that the 2b-th electron transport layer 114a_2b and the 2b-th electron transport layer 114b_2b are layers having a similar structure, and it is even more preferable that they are layers having the same structure. In particular, the light-emitting center substance contained in the first light-emitting layer 113a_1 and the light-emitting center substance contained in the first light-emitting layer 113b_1 are different substances, and the light-emitting center substance contained in the second light-emitting layer 113a_2 and the light-emitting center substance contained in the second light-emitting layer 113b_2 are different substances (for example, when 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, or when 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 when 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 device 130a and the light-emitting device 130b is different respectively. Therefore, usually, in order to bring out the performance of each of the light-emitting device 130a and the light-emitting device 130b, appropriate intermediate layers and electron transport layers must be selected and changed for each.However, by applying a layer having a first organic compound containing a triazine skeleton to the layer located on the cathode side in the stacked electron transport layer, that is, the 2b-th electron transport layer 114a_2b and the 2b-th electron transport layer 114b_2b, and applying a layer containing a second organic compound containing a phenanthroline skeleton to the first layer 119a and the first layer 119b, even if the 2b-th electron transport layer 114a_2b and the 2b-th electron transport layer 114b_2b are made into a continuous layer, the performance can be extracted in both the light-emitting device 130a and the light-emitting device 130b. That is, both productivity improvement and performance improvement can be achieved. Note that the first layer 119a and the first layer 119b may have the same configuration.

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

[0191] Figure 3 is a modified example of Figure 2. Since the light-emitting device 130a and the light-emitting device 130b1 are light-emitting devices having different emission colors, the optical path length between the electrodes that can amplify light emission using a microcavity is different. Therefore, in the light-emitting device 130b1, the distance between the electrodes can be adjusted by increasing the film 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 may be changed by thickening or adding a functional layer such as the hole transport layer 112b_21.

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

[0193] The light-emitting device 130c has an organic compound layer 103c between a first electrode 101c and a second electrode 102 on an insulating layer 175. The organic compound layer 103c has a structure in which a first light-emitting unit 501c and a second light-emitting unit 502c are laminated with an intermediate layer 116c therebetween. Although FIG. 4 shows an example in which two light-emitting units are laminated, a configuration in which three or more light-emitting units are laminated may also be used. 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 (a first a electron transport layer 114c_1a and a first b electron transport layer 114c_1b). Note that the first electron transport layer 114c_1 may have a single-layer structure. The intermediate layer 116c includes a second layer 117c, a third layer 118c, and a first layer 119c. The third layer 118c may or may not be present. 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 (a second a electron transport layer 114c_2a and a second b electron transport layer 114c_2b).

[0194] It is assumed that the emission color of the light-emitting device 130c has a shorter wavelength than those of the light-emitting devices 130a and 130b1. The electrode distance of the light-emitting device 130c is adjusted by the fact that the film thicknesses of the first light-emitting layer 113c_1 and the second light-emitting layer 113c_2 are thinner than the light-emitting layers in the other two light-emitting devices.

[0195] The second electron transport layer 114c_2 has a laminated structure. Further, among the laminated structures, it is preferable that the layer located on the cathode side, the second b electron transport layer 114c_2b, is a layer having a first organic compound containing a triazine skeleton. The first layer 119c is a layer containing a second organic compound containing 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 exhibit light emission of a similar color. Further, the light-emitting center substances contained in each other are preferably compounds in which the difference in the maximum peak wavelength in their emission spectra is 30 nm or less, more preferably compounds in which the difference is 20 nm or less, still more preferably compounds in which the difference is 10 nm or less, and it is even more preferable that the contained light-emitting center substances are the same.

[0197] Further, the first light-emitting layer 113a_1 and the first light-emitting layer 113c_1 are preferably separated, and the second light-emitting layer 113a_2 and the second light-emitting layer 113c_2 are preferably separated. Further, 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. Further, the light-emitting center substance contained in the first light-emitting layer 113a_1 and the light-emitting center substance contained in the first light-emitting layer 113c_1 are preferably different substances, and the light-emitting center substance contained in the second light-emitting layer 113a_2 and the light-emitting center substance contained in the second light-emitting layer 113c_2 are preferably different substances.

[0198] Note that 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 shown as examples that are independently separated in the light-emitting device 130a and the light-emitting device 130c, respectively, and the second electron transport layer 114a_2 and the second electron transport layer 114c_2 are shown as examples of a continuous layer. Thus, in one light-emitting device, both a continuous layer and a separated layer may be included. Thereby, a light-emitting device or a display device with a balance between productivity and characteristics can be manufactured. In particular, it is preferable that the 2b electron transport layer 114a_2b and the 2b electron transport layer 114c_2b are a continuous layer because both the light-emitting device 130a and the light-emitting device 130c can be made into light-emitting devices having good characteristics.

[0199] For example, in a three-color light-emitting device, when there are two light-emitting devices in which the light-emitting center substance is fluorescence and one light-emitting device in which the light-emitting center substance is phosphorescence, in the light-emitting device in which the light-emitting center substance is fluorescence, it is preferable to form the carrier transport layer as a continuous layer, and in the light-emitting device in which the light-emitting center substance is phosphorescence, it is preferable to form the carrier transport layer as a layer separated from the light-emitting device exhibiting another emission color. Or, in a three-color light-emitting device, when there are two light-emitting devices in which the light-emitting center substance is phosphorescence and one light-emitting device in which the light-emitting center substance is fluorescence, in the light-emitting device in which the light-emitting center substance is phosphorescence, it is preferable to form the carrier transport layer as a continuous layer, and in the light-emitting device in which the light-emitting center substance is fluorescence, it is preferable to form the carrier transport layer as a layer separated from the light-emitting device exhibiting another emission color.

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

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

[0202] The routing 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. Although only the FPC is illustrated here, a printed wiring board (PWB) may be attached to this FPC. The display device in this specification includes not only the display device main body but also a state in which an FPC or a PWB is attached thereto.

[0203] Next, the cross-sectional structure will be described with reference to FIG. 5(B). Although a drive circuit unit and a pixel unit are formed on the element substrate 610, here, the source line drive circuit 601 which is a drive circuit unit and one pixel in the pixel unit 602 are shown.

[0204] The element substrate 610 may be made of a substrate such as glass, quartz, organic resin, metal, alloy, semiconductor, etc., or may be made using a plastic substrate made of FRP (Fiber Reinforced Plastics), PVF (polyvinyl fluoride), polyester, acrylic resin, or the like.

[0205] The structure of the transistors used for the pixels and the drive circuits is not particularly limited. For example, an inverted staggered transistor or a staggered transistor may be used. Also, a top gate type transistor or a bottom gate type transistor may be used. The semiconductor material used for the transistors is not particularly limited, and for example, silicon, germanium, silicon carbide, gallium nitride, etc. can be used. Alternatively, an oxide semiconductor containing at least one of indium, gallium, and zinc, such as an In-Ga-Zn based metal oxide, may be used.

[0206] The crystallinity of the semiconductor material used for the transistors is also not particularly limited, and any of an amorphous semiconductor, a semiconductor having crystallinity (microcrystalline semiconductor, polycrystalline semiconductor, single crystal semiconductor, or a semiconductor having a crystal region in part) may be used. Using a semiconductor having crystallinity is preferable because deterioration of the transistor characteristics can be suppressed.

[0207] Here, in addition to the transistors provided in the above-mentioned pixels and drive circuits, for semiconductor devices such as transistors used for a touch sensor etc. to be described later, it is preferable to apply an oxide semiconductor. In particular, it is preferable to apply an oxide semiconductor having a wider band gap than silicon. By using an oxide semiconductor having a wider band gap than silicon, the current in the off state of the transistor can be reduced.

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

[0209] In particular, as the semiconductor layer, it is preferable to use an oxide semiconductor film having a plurality of crystal parts, wherein the c-axis of the crystal parts is oriented perpendicular to the surface to be formed of the semiconductor layer or the upper surface of the semiconductor layer, and there are no grain boundaries between adjacent crystal parts.

[0210] By using such a material as the semiconductor layer, fluctuations in electrical characteristics can be suppressed, and a highly reliable transistor can be realized.

[0211] Also, due to its low off-current, the transistor having the above-described semiconductor layer can hold the charge accumulated in the capacitor through the transistor for a long period of time. By applying such a transistor to a pixel, it is possible to stop the driving circuit while maintaining the gradation of the image displayed in each display area. As a result, an electronic device with extremely low power consumption can be realized.

[0212] For the purpose of stabilizing the characteristics of the transistor, etc., it is preferable to provide an underlayer film. As the underlayer 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 it can be formed as a single layer or by lamination. The underlayer film can be formed using a sputtering method, a CVD (Chemical Vapor Deposition) method (such as a plasma CVD method, a thermal CVD method, an MOCVD (Metal Organic CVD) method, etc.), an ALD (Atomic Layer Deposition) method, a coating method, a printing method, etc. Note that the underlayer film may not be provided if it is not necessary.

[0213] Note that FET623 indicates one of the transistors formed in the drive circuit unit 601. Also, the drive circuit may be formed of various CMOS circuits, PMOS circuits, or NMOS circuits. In the present embodiment, a driver integrated type in which the drive circuit is formed on a substrate is shown, but this is not necessarily required, and the drive circuit can also be formed outside the substrate instead of on the substrate.

[0214] The pixel portion 602 is formed by a plurality of pixels including a switching FET 611, a current control FET 612, and a first electrode 613 electrically connected to the drain thereof, but is not limited thereto, and may be a pixel portion combining three or more FETs and a capacitive element.

[0215] An insulator 614 is formed covering the end of the first electrode 613. Here, it can be formed by using a positive photosensitive acrylic resin film.

[0216] Also, in order to make the coating property of an organic compound layer or the like formed later good, a curved surface having a curvature is formed at the upper end or the lower end of the insulator 614. For example, when a positive photosensitive acrylic resin is used as the material of the insulator 614, it is preferable to provide a curved surface having a radius of curvature (0.2 μm to 3 μm) only at the upper end of the insulator 614. Also, as the insulator 614, either a negative photosensitive resin or a positive photosensitive resin can be used.

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

[0218] Further, the organic compound layer 616 is formed by various methods such as vapor deposition method using a vapor deposition mask, inkjet method, spin coating method, etc. The organic compound layer 616 includes the configuration as described in Embodiment 1. Further, as other materials constituting the organic compound layer 616, a low molecular compound or a high molecular compound (including oligomers and dendrimers) may be used.

[0219] Furthermore, as the material used for the second electrode 617 formed on the organic compound layer 616 and functioning as a cathode, it is preferable to use a material with a small work function (Al, Mg, Li, Ca, or their alloys and compounds (MgAg, MgIn, AlLi, etc.)). When the light generated in the organic compound layer 616 is transmitted through the second electrode 617, as the second electrode 617, it is good to use a laminate of a thin metal film with a reduced film thickness and a transparent conductive film (ITO, indium oxide containing 2 - 20 wt% zinc oxide, indium tin oxide containing silicon, zinc oxide (ZnO), etc.).

[0220] Note that a light - emitting device is formed by the first electrode 613, the organic compound layer 616, and the second electrode 617. The light - emitting device is the light - emitting device described in Embodiment 1. Although a plurality of light - emitting devices are formed in the pixel portion, in the display device of this embodiment, both the light - emitting device described in Embodiment 1 and the light - emitting device having other configurations may be mixed.

[0221] Furthermore, by bonding the sealing substrate 604 to the element substrate 610 with the sealing material 605, a structure is formed in which the light - emitting device 618 is provided in the 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 filling material, and in addition to the case where an inert gas (nitrogen, argon, etc.) is filled, it may also be filled with a sealing material. It is a preferable configuration to form a concave portion in the sealing substrate and provide a drying material therein to suppress deterioration due to the influence of moisture.

[0222] Note that it is preferable to use an epoxy resin and glass frit for the sealing material 605. Further, it is desirable that these materials are materials that hardly transmit moisture and oxygen. As materials used for the sealing 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, or the like can be used.

[0223] Although not shown in FIG. 5(B), a protective film may be provided on the second electrode 617. The protective film may be formed of an organic resin film or an inorganic insulating film. Further, the protective film may be formed so as to cover the exposed portion of the sealing material 605. Further, the protective film can be provided so as to cover the exposed side surfaces of the surfaces and side surfaces of the pair of substrates, the sealing layer, the insulating layer, and the like.

[0224] For the protective film, a material that hardly transmits impurities such as water can be used. Therefore, it is possible to effectively suppress the diffusion of impurities such as water from the outside to the inside.

[0225] As materials constituting the protective film, oxides, nitrides, fluorides, sulfides, ternary compounds, metals, polymers, or the like can be used. For example, materials 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, or the like, materials containing aluminum nitride, hafnium nitride, silicon nitride, tantalum nitride, titanium nitride, niobium nitride, molybdenum nitride, zirconium nitride, gallium nitride, or the like, materials containing nitrides containing titanium and aluminum, oxides containing titanium and aluminum, oxides containing aluminum and zinc, sulfides containing manganese and zinc, sulfides containing cerium and strontium, oxides containing erbium and aluminum, oxides containing yttrium and zirconium, or the like can be used.

[0226] The protective film is preferably formed using a film-forming method with good step coverage. One such technique is the ALD method. It is preferable to use a material that can be formed using the ALD method for the protective film. By using the ALD method, a protective film that is dense, has reduced defects such as cracks and pinholes, or has a uniform thickness can be formed. Also, the damage imparted to the processing member when forming the protective film can be reduced.

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

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

[0229] Since the display device in the present embodiment uses the light-emitting device described in Embodiment 1, a display device having good characteristics can be obtained. Specifically, since the light-emitting device described in Embodiment 1 has high luminous efficiency, it is possible to obtain a display device with low power consumption. Also, since the light-emitting device described in Embodiment 1 has good reliability, a display device with good reliability can be obtained. In addition, since the light-emitting device described in Embodiment 1 can be a light-emitting device with good chromaticity and color purity, a display device with good display quality can be obtained.

[0230] Also, the present embodiment can be freely combined with other embodiments.

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

[0232] The display device 100 has a pixel section 177 in which a plurality of pixels 178 are arranged in a matrix. Each pixel 178 has a sub-pixel 110R, a sub-pixel 110G, and a sub-pixel 110B.

[0233] In this specification and the like, when explaining matters common to, for example, the sub-pixel 110R, the sub-pixel 110G, and the sub-pixel 110B, they may be described by referring to them as sub-pixels 110. For other components distinguished by alphabets, when explaining matters common to them, they may be described using symbols with the alphabets omitted.

[0234] The sub-pixel 110R exhibits red light, the sub-pixel 110G exhibits green light, and the sub-pixel 110B exhibits blue light. Thereby, an image can be displayed on the pixel section 177. In this embodiment, three-color sub-pixels of red (R), green (G), and blue (B) are taken as examples for explanation, but combinations of sub-pixels of other colors may also be used. Also, the number of sub-pixels is not limited to three, and may be four or more. Examples of four sub-pixels include four-color sub-pixels of R, G, B, and white (W), four-color sub-pixels of R, G, B, and Y, and four sub-pixels of R, G, B, and infrared light (IR).

[0235] In this specification and the like, the row direction may be referred to as the X direction, and the column direction may be referred to as the Y direction. The X direction and the Y direction intersect, for example, perpendicularly.

[0236] FIG. 6(A) shows an example in which sub-pixels of different colors are arranged side by side in the X direction, and sub-pixels of the same color are arranged side by side in the Y direction. Note that sub-pixels of different colors may be arranged side by side in the Y direction, and sub-pixels of the same color may be arranged side by side in the X direction.

[0237] Outside the pixel section 177, a connection section 140 is provided, and an area 141 may be provided. When the area 141 is provided, the area 141 is provided between the pixel section 177 and the connection section 140. When the area 141 is provided, an organic compound layer is provided in the area 141. Also, a conductive layer 151C is provided in the connection section 140.

[0238] In FIG. 6(A), an example is shown in which the region 141 and the connection portion 140 are located on the right side of the pixel portion 177. However, the positions of the region 141 and the connection portion 140 are not particularly limited. Also, the region 141 and the connection portion 140 may be singular or plural.

[0239] FIG. 6(B) is an example of a cross-sectional view between the dashed-dotted lines A1 - A2 in FIG. 6(A). As shown in FIG. 6(B), 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). Openings reaching the conductive layer 172 are provided in the insulating layer 175, the insulating layer 174, and the insulating layer 173, and plugs 176 are provided so as to fill the openings.

[0240] In the pixel portion 177, a light-emitting device 130 is provided on the insulating layer 175 and the plug 176. Also, a protective layer 131 is provided so as to cover the light-emitting device 130. The substrate 120 is bonded by a resin layer 122 on the protective layer 131. Further, it is preferable that an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 are provided between adjacent light-emitting devices 130.

[0241] In FIG. 6(B), a plurality of cross-sections of the inorganic insulating layer 125 and the insulating layer 127 are shown. However, when the display device 100 is viewed from above, it is preferable that the inorganic insulating layer 125 and the insulating layer 127 are each connected into one.

[0242] In FIG. 6(B), as the light-emitting device 130, a light-emitting device 130R, a light-emitting device 130G, and a light-emitting device 130B are shown. The light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B are assumed to emit light of different colors. 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. Also, the light-emitting device 130R, the light-emitting device 130G, or the light-emitting device 130B may emit other visible light or infrared light.

[0243] The display device according to one aspect of the present invention can be a top emission type that emits light in a direction opposite to the substrate on which, for example, the light-emitting device is formed. Note that the display device according to one aspect of the present invention may be a bottom emission type.

[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 or may not be provided, but it is preferable to provide it because it can reduce damage to the organic compound layer 103R during processing.

[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. Note that the common layer 104 may or may not be provided, but it is preferable to provide it because it can reduce damage to the organic compound layer 103G during processing.

[0246] The light-emitting device 130B has the configuration as shown in Embodiment 1. It has 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. Note that the common layer 104 may or may not be provided, but it is preferably provided because it can reduce damage to the organic compound layer 103B during processing. Also, when the common layer 104 is provided, the laminated 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] Note that the common layer 104 is preferably an electron transport layer. Also, when it is an electron transport layer, the electron transport layer preferably has a laminated structure, and among the laminated layers, the layer on the second electrode side is the common layer 104 and the layer on the light-emitting layer side is the organic compound layer 103 is more preferable.

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

[0249] Of the pixel electrode and the common electrode of the light-emitting device 130, one functions as an anode and the other functions as a cathode. Hereinafter, unless otherwise specified, it will be described assuming that the pixel electrode functions as an anode and the common electrode functions as a cathode.

[0250] The organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B are independent in an island shape for each light-emitting device or for each emission color. By providing 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, and a display device with extremely high contrast can be realized. In particular, a display device with high current efficiency at low luminance can be realized.

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

[0252] The organic compound layer 103 is preferably provided so as to cover the upper surface and the side surface of the first electrode (pixel electrode) of the light-emitting device 130. Thereby, it becomes easier to increase the aperture ratio of the display device 100 as compared with a configuration in which the end portion of the organic compound layer 103 is located inside the end portion of the pixel electrode. Further, by covering the side surface of the pixel electrode of the light-emitting device 130 with the organic compound layer 103, it is possible to suppress the contact between the pixel electrode and the second electrode 102, and thus it is possible to suppress a short circuit of the light-emitting device 130.

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

[0254] As the conductive layer 151, for example, a metal material can be used. Specifically, for example, metals such as aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd), and alloys containing these appropriately combined can also be used.

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

[0256] The conductive layer 151 may have a laminated structure of a plurality of layers having different materials, and the conductive layer 152 may also have a laminated structure of a plurality of layers having different materials. In this case, the conductive layer 151 may have a layer using a material that can be used for the conductive layer 152 such as a conductive oxide, and the conductive layer 152 may also have a layer using a material that can be used for the conductive layer 151 such as a metal material. For example, when the conductive layer 151 has a laminated structure of two or more layers, the layer in contact with the conductive layer 152 can be a layer using a material that can be used for the conductive layer 152.

[0257] Subsequently, an example of a method for manufacturing the display device 100 having the configuration shown in FIG. 6(A) will be described with reference to FIGS. 7 to 12.

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

[0259] In addition, thin films (such as insulating films, semiconductor films, and conductive films) constituting the display device can be formed by wet film formation methods such as spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor blade method, slit coating, roll coating, curtain coating, or knife coating.

[0260] In addition, when processing the thin film constituting the display device, for example, it can be processed using a photolithography method.

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

[0262] For the etching of the thin film, a dry etching method, a wet etching method, a sandblasting method, or the like can be used.

[0263] First, as shown in FIG. 7(A), an insulating layer 171 is formed on a substrate (not shown). Subsequently, 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. Subsequently, 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 heat resistance sufficient to withstand at least subsequent heat treatment can be used. For example, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, an organic resin substrate, a single crystal semiconductor substrate made of silicon or silicon carbide, a polycrystalline semiconductor substrate, a compound semiconductor substrate such as silicon germanium, or a semiconductor substrate such as an SOI substrate can be used.

[0265] Subsequently, as shown in FIG. 7(A), openings reaching the conductive layer 172 are formed in the insulating layer 175, the insulating layer 174, and the insulating layer 173. Subsequently, a plug 176 is formed so as to fill the openings.

[0266] Subsequently, as shown in FIG. 7(A), a conductive film 151f that will later 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 later 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 on 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 having any one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used.

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

[0268] Subsequently, as shown in FIG. 7(B), for example, the conductive film 151f and the conductive film 152f in regions that do not overlap with the resist mask 191 are removed. Thereby, the conductive layer 151 and the conductive layer 152 are formed.

[0269] Subsequently, as shown in FIG. 7(C), the resist mask 191 is removed. The resist mask 191 can be removed, for example, by ashing using oxygen plasma.

[0270] Subsequently, as shown in FIG. 7(D), an insulating film 156f that will later become the insulating layer 156R, the insulating layer 156G, the insulating layer 156B, and the insulating layer 156C is formed on the conductive layer 152R, on the conductive layer 152G, on the conductive layer 152B, on the conductive layer 152C, and on the insulating layer 175.

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

[0272] Subsequently, as shown in FIG. 7(E), by processing the insulating film 156f, an insulating layer 156R, an insulating layer 156G, an insulating layer 156B, and an insulating layer 156C are formed.

[0273] Subsequently, as shown in FIG. 8(A), an organic compound film 103Rf is formed on the conductive layer 152R, on the conductive layer 152G, on the conductive layer 152B, and on the insulating layer 175. Note that, as shown in FIG. 8(A), the organic compound film 103Rf is not formed on the conductive layer 152C.

[0274] Subsequently, as shown in FIG. 8(A), 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] For 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. For 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 when forming 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, more preferably 100°C or higher and 120°C or lower. Since the light-emitting device according to one aspect of the present invention contains the first organic compound, a display device with good display quality can be provided even after a heating process at a higher temperature.

[0278] It is preferable to use a film that can be removed by a wet etching method or a dry etching method for the sacrificial film 158Rf and the mask film 159Rf.

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

[0280] As the sacrificial film 158Rf and the mask film 159Rf, one or more of, for example, 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 respectively.

[0281] For the sacrificial film 158Rf and the mask film 159Rf, respectively, for example, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloy materials containing the metal materials can be used. In particular, it is preferable to use a low melting point material such as aluminum or silver. By using a metal material capable of shielding ultraviolet rays for one or both of the sacrificial film 158Rf and the mask film 159Rf, it is possible to suppress the organic compound film 103Rf from being irradiated with ultraviolet rays during pattern exposure, and it is preferable because deterioration of the organic compound film 103Rf can be suppressed.

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

[0283] In the above metal oxide, instead of gallium, an element M (M is one or more selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium) may be used.

[0284] As the sacrificial film 158Rf and the mask film 159Rf, for example, it is preferable to use a semiconductor material such as silicon or germanium because it has a high affinity with the semiconductor manufacturing process. Alternatively, a compound containing the above semiconductor material can be used.

[0285] Also, as the sacrificial film 158Rf and the mask film 159Rf, various inorganic insulating films can be used respectively. In particular, the oxide insulating film is preferable because it has a higher adhesion to the organic compound film 103Rf than the nitride insulating film.

[0286] Subsequently, as shown in FIG. 8(A), a resist mask 190R is formed. The resist mask 190R can be formed by applying a photosensitive material (photoresist) and performing exposure and development.

[0287] The resist mask 190R is provided at a position overlapping the conductive layer 152R. The resist mask 190R is preferably also provided at a position overlapping the conductive layer 152C. Thereby, it is possible to suppress the conductive layer 152C from being damaged during the manufacturing process of the display device.

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

[0289] By using the wet 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 compared to the case of using the dry etching method. When using the wet etching method, for example, it is preferable to use a chemical solution such as a developer, an alkaline aqueous solution such as a tetramethylammonium hydroxide (TMAH) aqueous solution, a dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or an acidic aqueous solution of a mixed liquid thereof.

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

[0291] The resist mask 190R can be removed in the same manner as the resist mask 191.

[0292] Subsequently, as shown in FIG. 8(B), the organic compound film 103Rf is processed to form the organic compound layer 103R. For example, using the mask layer 159R and the sacrificial layer 158R as a hard mask, a part of the organic compound film 103Rf is removed to form the organic compound layer 103R.

[0293] As a result, as shown in FIG. 8(B), a laminated structure of the organic compound layer 103R, the sacrificial layer 158R, and the mask layer 159R remains on the conductive layer 152R. Also, the conductive layer 152G and the conductive layer 152B are exposed.

[0294] The processing of the organic compound film 103Rf is preferably performed by anisotropic etching. In particular, anisotropic dry etching is preferable. Alternatively, wet etching may be used.

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

[0296] Alternatively, a gas containing oxygen may be used as the etching gas. By including oxygen in the etching gas, the etching rate can be increased. Therefore, etching can be performed under low-power conditions while maintaining the etching rate at a sufficient speed. For this reason, damage to the organic compound film 103Rf can be suppressed. Furthermore, problems such as the adhesion of reaction products generated during etching can be suppressed.

[0297] When using the dry etching method, for example, it is preferable to use, as the etching gas, a gas containing one or more of H2, CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or elements of Group 18 such as He, Ar. Alternatively, it is preferable to use, as the etching gas, one or more of these and a gas containing oxygen. Alternatively, oxygen gas may be used as the etching gas.

[0298] Subsequently, as shown in FIG. 9(A), an organic compound film 103Gf that will later become the organic compound layer 103G is formed.

[0299] The organic compound film 103Gf can be formed by the same method as the method that can be used to form the organic compound film 103Rf. Also, the organic compound film 103Gf can have the same configuration as the organic compound film 103Rf.

[0300] Subsequently, as shown in FIG. 9(A), a sacrificial film 158Gf and a mask film 159Gf are formed in order. Thereafter, a resist mask 190G is formed. The materials and formation methods of the sacrificial film 158Gf and the mask film 159Gf are the same as the conditions 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 provided at a position overlapping the conductive layer 152G.

[0302] Subsequently, as shown in FIG. 9(B), using the resist mask 190G, a part of the mask film 159Gf is removed to form the mask layer 159G. The mask layer 159G remains on the conductive layer 152G. Then, the resist mask 190G is removed. Subsequently, using the mask layer 159G as a mask, a part of the sacrificial film 158Gf is removed to form the sacrificial layer 158G. Subsequently, the organic compound film 103Gf is processed to form the organic compound layer 103G.

[0303] Subsequently, as shown in FIG. 9(C), an organic compound film 103Bf is formed.

[0304] The organic compound film 103Bf can be formed by the same method as the method used for forming the organic compound film 103Rf. Also, the organic compound film 103Bf can have the same configuration as the organic compound film 103Rf.

[0305] Subsequently, as shown in FIG. 9(C), the sacrificial film 158Bf and the mask film 159Bf are formed in order. 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 applicable to the sacrificial film 158Rf and the mask film 159Rf. The material and formation method of the resist mask 190B are the same as the conditions applicable to the resist mask 190R.

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

[0307] Subsequently, as shown in FIG. 9(D), using the resist mask 190B, a part of the mask film 159Bf is removed to form the mask layer 159B. The mask layer 159B remains on the conductive layer 152B. Then, the resist mask 190B is removed. Subsequently, using the mask layer 159B as a mask, a part of the sacrificial film 158Bf is removed to form the sacrificial layer 158B. Subsequently, the organic compound film 103Bf is processed to form the organic compound layer 103B. For example, using the mask layer 159B and the sacrificial layer 158B as hard masks, a part of the organic compound film 103Bf is removed to form the organic compound layer 103B.

[0308] As a result, as shown in FIG. 9(D), a stacked structure of the organic compound layer 103B, the sacrificial layer 158B, and the mask layer 159B remains on the conductive layer 152B. Also, the mask layer 159R and the mask layer 159G are exposed.

[0309] Note that the side surfaces of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B are preferably perpendicular or substantially perpendicular to the formation surface. For example, it is preferable that the angle formed by the formation surface and these side surfaces is 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 using a photolithography method can be narrowed to 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. Here, the distance can be defined as, for example, the distance between two opposing end portions of two adjacent ones among the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B. By narrowing the distance between the island-like organic compound layers in this way, a display device having high definition and a large aperture ratio can be provided. Also, the distance between the first electrodes between adjacent light-emitting devices can also be narrowed, and can be, for example, 10 μm or less, 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less. Note that the distance between the first electrodes between adjacent light-emitting devices is preferably 2 μm or more and 5 μm or less.

[0311] Subsequently, as shown in FIG. 10(A), it is preferable to remove the mask layer 159R, the mask layer 159G, and the mask layer 159B.

[0312] For the mask layer removal step, the same method as the mask film processing step can be used. In particular, by using a wet etching method, damage to the organic compound layer 103 when removing the mask layer can be reduced compared to the case of using a dry etching method.

[0313] Alternatively, the mask layer may be removed by dissolving it in a polar solvent such as water or alcohol. Examples of alcohol include ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin.

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

[0315] Subsequently, as shown in FIG. 10(B), an inorganic insulating film 125f is formed.

[0316] Subsequently, as shown in FIG. 10(C), an insulating film 127f that will later become the insulating layer 127 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, respectively.

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

[0319] The inorganic insulating film 125f is preferably formed using, for example, the ALD method. Using the ALD method is preferable because film formation damage can be reduced and a film with high coverage can be formed. As the inorganic insulating film 125f, it is preferable to form an aluminum oxide film using, for example, the ALD method.

[0320] The insulating film 127f is preferably formed using the wet film formation method described above. The insulating film 127f is preferably formed using a photosensitive material, for example, by spin coating, and more specifically, is preferably formed using a photosensitive resin composition containing an acrylic resin.

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

[0322] The width of the insulating layer 127 to be formed later can be controlled by the exposure region of the insulating film 127f. In the present embodiment, processing is performed so that the insulating layer 127 has a portion overlapping the upper surface of the conductive layer 151.

[0323] The light used for exposure preferably includes i-line (wavelength 365 nm). Further, the light used for exposure may include at least one of g-line (wavelength 436 nm) and h-line (wavelength 405 nm).

[0324] Subsequently, as shown in FIG. 11(A), development is performed to remove the exposed region of the insulating film 127f and form the insulating layer 127a.

[0325] Subsequently, as shown in FIG. 11(B), an etching process is performed using the insulating layer 127a as a mask to remove a part of the inorganic insulating film 125f and reduce the film thickness of a part of the sacrificial layers 158R, 158G, and 158B. Thereby, an inorganic insulating layer 125 is formed under the insulating layer 127a. Also, the surfaces of the portions where the film thicknesses of the sacrificial layers 158R, 158G, and 158B are thin are exposed. Hereinafter, the etching process using the insulating layer 127a as a mask may be 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 formed using the same material as the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B, it is preferable because the first etching process can be performed in a batch manner.

[0327] When performing dry etching, it is preferable to use a chlorine-based gas. As the chlorine-based gas, Cl2, BCl3, SiCl4, CCl4, etc. can be used alone or in combination of two or more gases. Further, oxygen gas, hydrogen gas, helium gas, argon gas, etc. can be appropriately added to the above chlorine-based gas, either alone or in combination of two or more gases. By using dry etching, regions with a thin film thickness of the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B can be formed with good in-plane uniformity.

[0328] As the dry etching apparatus, a dry etching apparatus having a high-density plasma source can be used. As the 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 having parallel plate electrodes can be used.

[0329] Also, it is preferable to perform the first etching process by wet etching. By using the wet etching method, the damage applied to the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B can be reduced as compared with the case of using the dry etching method. For example, wet etching can be performed using an alkaline solution. For example, TMAH, which is an alkaline solution, can be used for wet etching of the aluminum oxide film. Also, an acid solution containing fluoride can be used. In this case, wet etching can be performed by a paddle method. When the inorganic insulating film 125f is formed using the same material as the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B, it is preferable because the above etching process can be performed collectively.

[0330] In the first etching process, the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B are not completely removed, and the etching process is stopped with the film thickness reduced. In this way, by leaving the corresponding sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B on the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B, it is possible to prevent the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B from being damaged in the subsequent process.

[0331] Subsequently, it is preferable to expose the entire substrate and irradiate the insulating layer 127a with visible light or ultraviolet light. The energy density of the exposure is preferably greater than 0 mJ / cm 2 and less than or equal to 800 mJ / cm 2 more preferably greater than 0 mJ / cm 2 and less than or equal to 500 mJ / cm 2 Performing such exposure after development may improve the transparency of the insulating layer 127a. Also, in a subsequent process, it may be possible to reduce the substrate temperature required for the heat treatment to deform the insulating layer 127a into a tapered shape.

[0332] Here, as the sacrificial layers 158R, 158G, and 158B, the presence of a barrier insulating layer against oxygen (for example, an aluminum oxide film or the like) can reduce the diffusion of oxygen into the organic compound layers 103R, 103G, and 103B.

[0333] Subsequently, a heat treatment (also referred to as post-baking) is performed. By performing the heat treatment, the insulating layer 127a can be deformed into an insulating layer 127 having a tapered shape on the side surface (FIG. 11(C)). The 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, more preferably 70°C or higher and 130°C or lower. The heating atmosphere may be an air atmosphere or an inert gas atmosphere. Also, the heating atmosphere may be an atmospheric pressure 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 but leaving the sacrificial layers 158R, 158G, and 158B in a state where the film thickness is reduced, it is possible to prevent the organic compound layers 103R, 103G, and 103B from being damaged and deteriorated in the heat treatment. Therefore, the reliability of the light-emitting device can be enhanced.

[0335] Subsequently, as shown in FIG. 12(A), using the insulating layer 127 as a mask, an etching process is performed to remove a part of the sacrificial layers 158R, 158G, and 158B. Thereby, openings are formed in each of the sacrificial layers 158R, 158G, and 158B, and the upper surfaces of the organic compound layers 103R, 103G, 103B, and the conductive layer 152C are exposed. Hereinafter, this etching process may be referred to as the second etching process.

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

[0337] The second etching process is performed by wet etching. By using the wet etching method, the damage applied to the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B can be reduced as compared with the case of using the dry etching method. Wet etching can be performed using, for example, an alkaline solution or an acidic solution. It is preferably an aqueous solution so that the organic compound layer 103 does not dissolve.

[0338] Subsequently, as shown in FIG. 12(B), a common electrode 155 is formed on the organic compound layer 103R, on the organic compound layer 103G, on the organic compound layer 103B, on the conductive layer 152C, and on 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] Subsequently, as shown in FIG. 12(C), 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] Subsequently, the display device can be manufactured by bonding the substrate 120 onto the protective layer 131 using the resin layer 122.

[0341] As described above, in the method for manufacturing a display device according to one embodiment of the present invention, the island-shaped organic compound layer 103R, the island-shaped organic compound layer 103G, and the organic compound layer 103B are not formed using a fine metal mask, but are formed by processing after forming a film on one surface. Therefore, the island-shaped layers can be formed with a uniform thickness. And a high-definition display device or a display device with a high aperture ratio can be realized. Further, even if the fineness or aperture ratio is high and the distance between sub-pixels is extremely short, it is possible to suppress the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B from contacting each other in adjacent sub-pixels. Therefore, it is possible to suppress the generation of leakage current between sub-pixels. Thereby, crosstalk can be prevented, and a display device with extremely high contrast can be realized. Further, even in a display device having a tandem type light-emitting device manufactured using a photolithography method, a display device with good characteristics can be provided.

[0342] (Embodiment 4) In the present embodiment, a display device according to one embodiment of the present invention will be described.

[0343] The display device of the present embodiment can be a high-definition display device. Therefore, the display device of the present embodiment can be used, for example, in a display unit of an information terminal device (wearable device) such as a wristwatch type and a bracelet type, a VR device such as a head-mounted display (HMD), and a display unit of a wearable device that can be worn on the head such as a glasses type AR device.

[0344] Further, the display device of the present embodiment can be a high-resolution display device or a large-sized display device. Therefore, the display device of the present embodiment can be used, for example, in an electronic device having a relatively large screen such as a television device, a desktop or notebook personal computer, a monitor for a computer, digital signage, and a large game machine such as a pachinko machine, as well as in a display unit of a digital camera, a digital video camera, a digital photo frame, a mobile phone, a portable game machine, a portable information terminal, and an audio playback device.

[0345] [Display module] FIG. 13(A) shows a perspective view of the display module 280. 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 may be any one of the display devices 100B to 100E 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 an area for displaying an image in the display module 280, and is an area where light from each pixel provided in a pixel unit 284 described later can be visually recognized.

[0347] FIG. 13(B) shows a perspective view schematically showing the configuration on the substrate 291 side. On the substrate 291, a circuit unit 282, a pixel circuit unit 283 on the circuit unit 282, and a pixel unit 284 on the pixel circuit unit 283 are stacked. Further, a terminal unit 285 for connecting to the FPC 290 is provided in a portion that does not overlap with the pixel unit 284 on the substrate 291. The terminal unit 285 and the circuit unit 282 are electrically connected by a wiring unit 286 formed of a plurality of wirings.

[0348] The pixel unit 284 includes a plurality of pixels 284a arranged periodically. An enlarged view of one pixel 284a is shown on the right side of FIG. 13(B). Various configurations described in the previous embodiments can be applied to the pixel 284a.

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

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

[0351] The circuit section 282 has a circuit for driving each pixel circuit 283a of the pixel circuit section 283. For example, it preferably has one or both of a gate line driving circuit and a source line driving circuit. In addition, it may have at least one of an arithmetic circuit, a memory circuit, a power supply circuit, and the like.

[0352] The FPC 290 functions as a wiring for supplying a video signal, a power supply potential, or the like from the outside to the circuit section 282. Also, an IC may be mounted on the FPC 290.

[0353] The display module 280 can be configured such that one or both of the pixel circuit section 283 and the circuit section 282 are laminated below the pixel section 284, so that the aperture ratio (effective display area ratio) of the display section 281 can be made extremely high.

[0354] Such a display module 280 is extremely high-definition, and thus can be suitably used for VR devices such as HMDs or glasses-type AR devices. For example, even in the case of a configuration in which the display section of the display module 280 is viewed through a lens, since the display module 280 has an extremely high-definition display section 281, pixels cannot be viewed even when the display section is enlarged by the lens, and a display with a high sense of immersion can be performed. Also, the display module 280 is not limited to this, and can be suitably used for electronic devices having a relatively small display section.

[0355] [Display device 100A] The display device 100A shown in FIG. 14(A) has 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 the substrate 291 in FIGS. 14(A) and 14(B). 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 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region in which the substrate 301 is doped with impurities and functions as a source or a drain. The insulating layer 314 is provided to cover the side surface of the conductive layer 311.

[0357] Also, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301.

[0358] 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 therebetween. The conductive layer 241 functions as one electrode of the capacitor 240, the conductive layer 245 functions as the other electrode of the capacitor 240, and the insulating layer 243 functions as a 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 or drain of the transistor 310 by 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 via the insulating layer 243.

[0361] Covering a capacity of 240, an insulating layer 255 is provided, an insulating layer 174 is provided on the insulating layer 255, and an insulating layer 175 is provided on the insulating layer 174. On the insulating layer 175, a light-emitting device 130R, a light-emitting device 130G, and a light-emitting device 130B are provided. An insulator is provided in the region between adjacent light-emitting devices.

[0362] An insulating layer 156R is provided so as to have a region overlapping with the side surface of the conductive layer 151R, an insulating layer 156G is provided so as to have a region overlapping with the side surface of the conductive layer 151G, and an insulating layer 156B is provided so as to have a region overlapping with the side surface of the conductive layer 151B. Also, a conductive layer 152R is provided so as to cover the conductive layer 151R and the insulating layer 156R, a conductive layer 152G is provided so as to cover the conductive layer 151G and the insulating layer 156G, and a conductive layer 152B is provided so as to cover the conductive layer 151B and the insulating layer 156B. A sacrificial layer 158R is located on the organic compound layer 103R, a sacrificial layer 158G is located on the organic compound layer 103G, and a 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 or drain of the transistor 310 by a plug 256 embedded in the insulating layer 243, the insulating layer 255, the insulating layer 174, and the insulating layer 175, a conductive layer 241 embedded in the insulating layer 254, and a plug 271 embedded in the insulating layer 261. Various conductive materials can be used for the plug.

[0364] Also, a protective layer 131 is provided on the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B. On the protective layer 131, the substrate 120 is bonded 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 the substrate 292 in FIG. 13(A).

[0365] FIG. 14(B) is a modified example of the display device 100A shown in FIG. 14(A). The display device shown in FIG. 14(B) has a coloring layer 132R, a coloring layer 132G, and a coloring layer 132B, and the light-emitting device 130 has an area that overlaps with one of the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B. In the display device shown in FIG. 14(B), the light-emitting device 130 can emit, for example, white light. Further, for example, the coloring layer 132R can transmit red light, the coloring layer 132G can transmit green light, and the coloring layer 132B can transmit blue light.

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

[0367] The display device 100B has a configuration in which a substrate 352 and a substrate 351 are bonded together. In FIG. 15, the substrate 352 is shown by a broken line.

[0368] The display device 100B includes a pixel portion 177, a connection portion 140, a circuit 356, a wiring 355, and the like. FIG. 15 shows an example in which an IC 354 and an FPC 353 are mounted on the display device 100B. Therefore, the configuration shown in FIG. 15 can also be referred to as a display module having the display device 100B, an IC (integrated circuit), and an FPC. Here, a display device in which a connector such as an FPC is attached to the substrate of the display device, or a display device in which an IC is mounted on the substrate is called a display module.

[0369] The connection portion 140 is provided outside the pixel portion 177. The connection portion 140 may be single or plural. The connection portion 140 electrically connects the common electrode of the light-emitting device and the conductive layer, and can supply a potential to the common electrode.

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

[0371] The wiring 355 has a function of supplying signals and power to the pixel portion 177 and the circuit 356. The signals and power are input to the wiring 355 from the outside via the FPC 353 or from the IC 354.

[0372] FIG. 15 shows an example in which the IC 354 is provided on the substrate 351 by a COG (Chip On Glass) method, a COF (Chip on Film) method, or the like. As the IC 354, for example, an IC having a scanning line driving circuit, a signal line driving circuit, or the like can be applied. Note that the display device 100B and the display module may be configured not to include an IC. Further, the IC may be mounted on the FPC by, for example, a COF method.

[0373] FIG. 16 shows an example of a cross section when a part of the region including the FPC 353, a part of the circuit 356, a part of the pixel portion 177, a part of the connection portion 140, and a part of the region including the end portion of the display device 100B in FIG. 15 are each cut, as the display device 100C.

[0374] [Display device 100C] The display device 100C shown in FIG. 16 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 of 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 so as to have a region in contact with the side surface of the conductive layer 151R, and the conductive layer 152R is provided so as to cover the conductive layer 151R and the insulating layer 156R.

[0378] For 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, since they are the same as the conductive layer 224R, the conductive layer 151R, the conductive layer 152R, the insulating layer 156R in the light-emitting device 130R, detailed descriptions thereof are omitted.

[0379] Recesses are formed in the conductive layers 224R, 224G, and 224B so as to cover the openings provided in the insulating layer 214. The layer 128 is embedded in the recesses.

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

[0381] The layer 128 may be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be appropriately used for the layer 128. In particular, the layer 128 is preferably formed using an insulating material, and particularly preferably formed using an organic insulating material. For example, the organic insulating material that can be used for the aforementioned insulating layer 127 can be applied to the layer 128.

[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 adhered via an adhesive layer 142. A light-shielding layer 157 is provided on the substrate 352. For encapsulating the light-emitting device 130, a solid encapsulation structure, a hollow encapsulation structure, or the like can be applied. In FIG. 16, the space between the substrate 352 and the substrate 351 is filled with the adhesive layer 142, and a solid encapsulation structure is applied. Alternatively, the space may be filled with an inert gas (such as nitrogen or argon), and a hollow encapsulation structure may be applied. At this time, the adhesive layer 142 may be provided so as not to overlap with the light-emitting device. Further, the space may be filled with a resin different from the adhesive layer 142 provided in a frame shape.

[0383] In FIG. 16, an example is shown in which the connection portion 140 has a conductive layer 224C obtained by processing the same conductive film as the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B, a conductive layer 151C obtained by processing the same conductive film as the conductive layer 151R, the conductive layer 151G, and the conductive layer 151B, and a conductive layer 152C obtained by processing the same conductive film as the conductive layer 152R, the conductive layer 152G, and the conductive layer 152B. Further, in FIG. 16, an example is shown in which an insulating layer 156C is provided so as to have a region overlapping the side surface of the conductive layer 151C.

[0384] The display device 100C is a top emission type. The light emitted from the light-emitting device is emitted toward the substrate 352 side. It is preferable to use a material having high transmittance for visible light for the substrate 352. The pixel electrode contains a material that reflects visible light, and the counter electrode (common electrode 155) contains a material that transmits visible light.

[0385] On the substrate 351, an insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are provided in this order. A part of the insulating layer 211 functions as a gate insulating layer of each transistor. A part of the insulating layer 213 functions as a gate insulating layer of each transistor. The insulating layer 215 is provided to cover the transistor. The insulating layer 214 is provided to cover the transistor and has a function as a planarization layer. Note that the number of gate insulating layers and the number of insulating layers covering the transistor are not limited, and each may be a single layer or two or more layers.

[0386] As the insulating layer 211, the insulating layer 213, and the insulating layer 215, it is preferable to use an inorganic insulating film respectively.

[0387] An organic insulating layer is suitable for the insulating layer 214 that functions as a planarization layer.

[0388] The transistor 201 and the transistor 205 include a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as a source and a drain, a semiconductor layer 231, an insulating layer 213 that functions as a gate insulating layer, and a conductive layer 223 that functions as a gate.

[0389] In a region of the substrate 351 where the substrate 352 does not overlap, a connection portion 204 is provided. In the connection portion 204, a source electrode or a drain electrode of the transistor 201 is electrically connected to the FPC 353 via the conductive layer 166 and the connection layer 242. The conductive layer 166 is shown as an example of a laminated structure of a conductive film obtained by processing the same conductive film as the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B, a conductive film obtained by processing the same conductive film as the conductive layer 151R, the conductive layer 151G, and the conductive layer 151B, and a conductive film obtained by processing the same conductive film as the conductive layer 152R, the conductive layer 152G, and the conductive layer 152B. On the upper surface of the connection portion 204, the conductive layer 166 is exposed. Thereby, the connection portion 204 and the FPC 353 can be electrically connected via the connection layer 242.

[0390] It is preferable to provide a light-shielding layer 157 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, at the connection portion 140, and in the circuit 356 and the like. In addition, various optical members can be arranged outside the substrate 352.

[0391] As the substrate 351 and the substrate 352, materials that can be used for the substrate 120 can be applied respectively.

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

[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] The display device 100D shown in FIG. 17 is mainly different from the display device 100C shown in FIG. 16 in that it is a bottom emission type display device.

[0395] The light emitted by the light-emitting device is emitted toward the substrate 351 side. It is preferable to use a material with high transmittance for visible light for the substrate 351. On the other hand, the light-transmitting property of the material used for the substrate 352 does not matter.

[0396] It is preferable to form a light-shielding layer 317 between the substrate 351 and the transistor 201 and between the substrate 351 and the transistor 205. In FIG. 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 has 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] For the conductive layers 112R, 112B, 126R, 126B, 129R, and 129B, materials with high transparency to visible light are used respectively. It is preferable to use a material that reflects visible light for the second electrode 102.

[0400] In FIG. 17, although the light-emitting device 130G is not shown, the light-emitting device 130G is also provided.

[0401] Also, in FIG. 17 and the like, an example is shown in which the upper surface of the layer 128 has a flat portion, but the shape of the layer 128 is not particularly limited.

[0402] [Display device 100D2] The display device 100D2 shown in FIG. 18(A) is an example of a bottom emission type display device different from the display device 100D shown in FIG. 17. The display device 100D2 is different from the display device 100D in that it has an organic resin layer 180. In the figure, the reference numerals of the same components as those in FIG. 17 may be omitted, and the details thereof may be referred to the description of FIG. 17.

[0403] Also, FIG. 18(B) shows the top layout of the pixel 178 (pixel 178a and pixel 178b) having sub-pixels 110 (sub-pixel 110R, sub-pixel 110G, sub-pixel 110B, sub-pixel 110W), and FIG. 18(C) shows 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. The width between the light-shielding layers 317 is the width 110Rw in the light-emitting region of the sub-pixel 110R.

[0404] As shown in FIG. 18(A), the organic resin layer 180 is provided on the insulating layer 214. As shown in the region surrounded by the dashed-dotted line in FIG. 18(A) and FIG. 18(C), the organic resin layer 180 has concave portions 181 (concave portion 181a, concave portion 181b) having a curved surface in at least the region where sub-pixels are formed. Note that 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 that has traveled to the region overlapping with the light-shielding layer 317 is refracted and can be extracted from the light-emitting region, so that the light-emitting efficiency can be improved.

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

[0406] In addition, in FIG. 18, the upper surface shape of the concave portion is shown as a hexagon (FIG. 18(C)) and the cross-sectional shape is shown as a semi-circle (FIG. 18(A)), but other shapes may be used as necessary. For example, as the upper surface shape of the concave portion, polygons such as a triangle, a quadrangle (including a rectangle and a square), a pentagon, etc., a shape in which the corners of these polygons are rounded, an ellipse, or a circle, etc. can be mentioned.

[0407] As the organic resin layer 180, an insulating layer having an organic material can be used. For example, as the organic resin layer 180, an acrylic resin, a polyimide resin, an epoxy resin, an imide resin, a polyamide resin, a polyimide amide resin, a silicone resin, a siloxane resin, a benzocyclobutene-based resin, a phenol resin, and precursors of these resins, etc. can be applied. Also, as the organic resin layer 180, an organic material such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinyl pyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin may be used.

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

[0409] The organic resin layer 180 may 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, or the organic resin layer 180 may contain a pigment that absorbs visible light. As the organic resin layer 180, for example, a resin that can be used as a color filter that transmits red, blue, or green light and absorbs other light, or a resin that contains carbon black as a pigment and functions as a black matrix can be used.

[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 be covered with an insulating layer 127.

[0411] In addition, the first electrode 101 formed on the organic resin layer 180 has similarly recessed portions along the recessed portions of the organic resin layer 180. Further, the organic compound layer 103 formed on the first electrode 101 has similarly recessed portions along the recessed portions of the first electrode 101. Further, the common layer 104 formed on the organic compound layer 103 has similarly recessed portions along the recessed portions of the organic compound layer 103. Further, the second electrode 102 formed on the common layer 104 has similarly recessed portions along the recessed portions of the common layer 104. That is, the recessed portions of the organic resin layer 180, the first electrode 101, the organic compound layer 103, the common layer 104, and the second electrode 102 have a structure that overlaps 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 the structure is bonded to the substrate 352 via an adhesive layer 142.

[0413] Note that although the light-emitting devices 130G and 130B are not shown in FIG. 18, the light-emitting devices 130G and 130B are also provided.

[0414] [Display device 100E] The display device 100E shown in FIG. 19 is a modified example of the display device 100C shown in FIG. 16, and mainly differs from the display device 100C in that it has a colored layer 132R, a colored layer 132G, and a colored layer 132B.

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

[0416] In the display device 100E, the light-emitting device 130 can emit, for example, white light. Also, for example, the colored layer 132R can transmit red light, the colored layer 132G can transmit green light, and the colored layer 132B can transmit blue light. Note that the display device 100E may be configured such that the colored layer 132R, the colored layer 132G, and the colored layer 132B are provided between the protective layer 131 and the adhesive layer 142.

[0417] [Display device 100E2] The display device 100E2 shown in FIG. 20(A) is a modified example of the display device 100E shown in FIG. 19, and has microlenses 182 on the colored layer 132R, the colored layer 132G, and the colored layer 132B. Note that in the figure, the reference numerals of the same components as those in FIG. 19 may be omitted, and the details thereof may be referred to the description of FIG. 19.

[0418] Further, FIG. 20(B) shows the top layout of pixels 178 (pixel 178a and pixel 178b) having sub-pixels 110 (sub-pixel 110R, sub-pixel 110G, and sub-pixel 110B), and FIG. 20(C) shows a top view of the microlenses 182 in the region where the sub-pixels 110R and 110G included in the pixel 178 are formed. Note that the region where the common electrode 155 is in contact with the organic compound layer 103 has a width 110Gw in the light-emitting region of the sub-pixel 110G.

[0419] The display device 100E2 shown in FIG. 20(A) is provided with a planarization film 143 on the protective layer 131, and a coloring layer 132R, a coloring layer 132G, and a coloring layer 132B are provided on the planarization film 144. A planarization film 144 is provided so as to cover the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B. A microlens 182 is provided on the planarization film 144.

[0420] Note that as shown in FIG. 20(C), the microlenses 182 may be provided for each sub-pixel in the region where the sub-pixels are formed.

[0421] In FIG. 20(C), the top shape of the microlens 182 is shown as a hexagon, but it may be another shape as necessary. For example, the top shape of the concave portion includes polygons such as a triangle, a quadrangle (including a rectangle and a square), a pentagon, a shape in which the corners of these polygons are rounded, an ellipse, or a circle.

[0422] The microlens 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. Also, in this specification, when a plurality of configuration examples are shown in one embodiment, the configuration 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 the present embodiment has a display device according to an aspect of the present invention in a display unit. The display device according to an 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 the electronic device include, in addition to electronic devices having a relatively large screen such as a television device, a desktop or notebook personal computer, a monitor for a computer, a digital signage, a large game machine such as a pachinko machine, a digital camera, a digital video camera, a digital photo frame, a mobile phone, a portable game machine, a portable information terminal, an audio playback device, and the like.

[0427] An example of a wearable device that can be worn on the head will be described with reference to FIGS. 21(A) to 21(D).

[0428] The electronic device 700A shown in FIG. 21(A) and the electronic device 700B shown in FIG. 21(B) each include a pair of display panels 751, a pair of housings 721, a communication unit (not shown), a pair of mounting parts 723, a control unit (not shown), an imaging unit (not shown), a pair of optical members 753, a frame 757, and a pair of nose pads 758.

[0429] The display device according to an aspect of the present invention can be applied to the display panel 751. Therefore, an electronic device with high reliability can be obtained.

[0430] The electronic device 700A and the electronic device 700B can each project the image displayed on the display panel 751 onto the display area 756 of the optical member 753. Since the optical member 753 has translucency, the user can view the image displayed in the display area by superimposing it on the transmitted image viewed through the optical member 753.

[0431] The electronic device 700A and the electronic device 700B may be provided with a camera capable of imaging the front as an imaging unit. Further, the electronic device 700A and the electronic device 700B each include an acceleration sensor such as a gyro sensor, so that the orientation of the user's head can be detected and an image corresponding to the orientation can be displayed on the display area 756.

[0432] The communication unit has a wireless communication device, and the wireless communication device can supply, for example, a video signal. In addition to or instead of the wireless communication device, a connector to which a cable for supplying a video signal and a power potential can be connected may be provided.

[0433] Further, the electronic device 700A and the electronic device 700B are provided with a battery and can be charged by one or both of wireless and wired methods.

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

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

[0436] The electronic device 800A shown in FIG. 21(C) and the electronic device 800B shown in FIG. 21(D) each have 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 device according to one aspect of the present invention can be applied to the display unit 820. Therefore, a highly reliable electronic device can be obtained.

[0438] The display unit 820 is provided at a position inside the housing 821 where it can be visually recognized through the lens 832. Also, by displaying different images on the pair of display units 820, three-dimensional display using parallax can be performed.

[0439] It is preferable that the electronic device 800A and the electronic device 800B each have a mechanism capable of adjusting the left and right positions of the lens 832 and the display unit 820 so that they are in optimal 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 by the wearing 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 for the imaging unit 825. Also, a plurality of cameras may be provided so as to be capable of corresponding to a plurality of viewing angles such as telephoto and wide angle.

[0442] The electronic device 800A may have a vibration mechanism that functions as a bone conduction earphone.

[0443] The electronic device 800A and the electronic device 800B may each have an input terminal. A video signal from a video output device or the like and a cable for supplying power for charging a battery provided in the electronic device can be connected to the input terminal.

[0444] The electronic device according to one aspect of the present invention may have a function of performing wireless communication with the earphone 750.

[0445] Also, the electronic device may have an earphone unit. The electronic device 700B shown in FIG. 21(B) has an earphone unit 727. A part of the wiring connecting the earphone unit 727 and the control unit may be arranged inside the housing 721 or the wearing unit 723.

[0446] Similarly, the electronic device 800B shown in FIG. 21(D) has an earphone unit 827. For example, the earphone unit 827 and the control unit 824 can be configured to be wired-connected to each other.

[0447] As described above, as the electronic device according to an aspect of the present invention, both the glasses type (such as the electronic devices 700A and 700B) and the goggle type (such as the electronic devices 800A and 800B) are suitable.

[0448] The electronic device 6500 shown in FIG. 22(A) is a portable information terminal 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 device according to an aspect of the present invention can be applied to the display unit 6502. Therefore, a highly reliable electronic device can be obtained.

[0451] FIG. 22(B) is a schematic cross-sectional view including an end portion on the microphone 6506 side of 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 arranged 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 by an adhesive layer (not shown).

[0454] In the region outside the display unit 6502, a part of the display panel 6511 is folded back, and the 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 the printed circuit board 6517.

[0455] The display device according to one aspect of the present invention can be applied to the display panel 6511. Therefore, 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 back a part of the display panel 6511 and arranging the connection part with the FPC 6515 on the back side of the pixel part, a narrow bezel electronic device can be realized.

[0456] An example of a television device is shown in FIG. 22(C). The television device 7100 has a display unit 7000 incorporated in a housing 7171. Here, a configuration in which the housing 7171 is supported by a stand 7173 is shown.

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

[0458] The operation of the television device 7100 shown in FIG. 22(C) can be performed by an operation switch provided in the housing 7171 and a separate remote control operation unit 7151.

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

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

[0461] Figures 22(E) and 22(F) show an example of digital signage.

[0462] The digital signage 7300 shown in Fig. 22(E) includes a housing 7301, a display unit 7000, a speaker 7303, etc. Furthermore, it can have an LED lamp, operation keys (including a power switch or an operation switch), connection terminals, various sensors, a microphone, etc.

[0463] Fig. 22(F) shows a digital signage 7400 attached to a cylindrical column 7401. The digital signage 7400 has a display unit 7000 provided along the curved surface of the column 7401.

[0464] In Figs. 22(E) and 22(F), the display device according to one aspect of the present invention can be applied to the display unit 7000. Therefore, a highly reliable electronic device can be obtained.

[0465] The larger the display unit 7000 is, the more information can be provided at one time. Also, the larger the display unit 7000 is, the more likely it is to catch people's eyes, and for example, the advertising effect can be enhanced.

[0466] Also, as shown in Figs. 22(E) and 22(F), the digital signage 7300 or the digital signage 7400 is preferably capable of wireless communication and cooperation with an information terminal 7311 or an information terminal 7411 such as a smartphone held by a user.

[0467] The electronic device shown in Figs. 23(A) to 23(G) 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 (including a function of measuring force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared rays), a microphone 9008, etc.

[0468] The electronic devices shown in FIGS. 23(A) to 23(G) have various functions. For example, they can have functions such as displaying various information (still images, moving images, text images, etc.) on a display unit, a touch panel function, a function of displaying a calendar, date, or time, etc., a function of controlling processing by various software (programs), a wireless communication function, a function of reading and processing programs or data recorded on a recording medium, and so on.

[0469] Details of the electronic devices shown in FIGS. 23(A) to 23(G) will be described below.

[0470] FIG. 23(A) is a perspective view showing a portable information terminal 9171. The portable information terminal 9171 can be used, for example, as a smartphone. Note that the portable information terminal 9171 may be provided with a speaker 9003, a connection terminal 9006, a sensor 9007, or the like. Also, the portable information terminal 9171 can display character and image information on its plurality of surfaces. FIG. 23(A) shows an example in which three icons 9050 are displayed. Also, information 9051 indicated by a dashed rectangle can be displayed on other surfaces of the display unit 9001. Examples of the information 9051 include notifications of incoming calls such as e-mail, SNS, telephone, etc., titles of e-mail or SNS, sender names, dates, times, remaining battery levels, radio wave intensities, and the like. Or, icons 9050 or the like may be displayed at the position where the information 9051 is displayed.

[0471] FIG. 23(B) 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 is shown in which information 9052, information 9053, and information 9054 are respectively displayed on different surfaces. For example, the user can also confirm the information 9053 displayed at a position where it can be observed from above the portable information terminal 9172 in a state where the portable information terminal 9172 is stored in the breast pocket of a jacket.

[0472] FIG. 23(C) is a perspective view showing a tablet terminal 9173. As an example, the tablet terminal 9173 can execute various applications such as mobile phones, e-mails, text viewing and creation, music playback, Internet communication, computer games, etc. The tablet terminal 9173 has a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front surface of the housing 9000, an operation key 9005 as an operation button on the left side surface of the housing 9000, and a connection terminal 9006 on the bottom surface.

[0473] FIG. 23(D) is a perspective view showing a wristwatch-type portable information terminal 9200. The portable information terminal 9200 can be used as, for example, a smart watch (registered trademark). Further, the display surface of the display unit 9001 is provided to be curved, and display can be performed along the curved display surface. Further, the portable information terminal 9200 can also make a hands-free call by mutually communicating with, for example, a wireless communication-capable headset. Further, the portable information terminal 9200 can also mutually transmit data with other information terminals and perform charging through the connection terminal 9006. Note that the charging operation may be performed by wireless power supply.

[0474] FIGS. 23(E) to 23(G) are perspective views showing a foldable portable information terminal 9201. FIG. 23(E) shows the portable information terminal 9201 in an unfolded state, FIG. 23(G) shows the folded state, and FIG. 23(F) is a perspective view of a state in the process of changing from one of FIGS. 23(E) and 23(G) to the other. The portable information terminal 9201 has excellent portability in the folded state and excellent display comprehensibility due to a seamless wide display area in the unfolded state. The display unit 9001 included in the portable information terminal 9201 is supported by three housings 9000 connected by a hinge 9055. For example, the display unit 9001 can be bent with a curvature radius of 0.1 mm or more and 150 mm or less.

[0475] This embodiment can be appropriately combined with other embodiments or examples. Also, in this specification, when a plurality of configuration examples are shown within one embodiment, it is possible to appropriately combine the configuration examples.

Example

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

[0477]

Chemical

[0478]

Chemical

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

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

[0481] After that, the substrate was introduced into a vacuum evaporation apparatus whose interior was evacuated to about 1 × 10 -4 Pa, and in the heating chamber of the vacuum evaporation apparatus, vacuum baking was performed at 170 °C for 30 minutes, and then the substrate was allowed to cool for about 30 minutes.

[0482] Next, the substrate was fixed to a holder provided in a vacuum deposition apparatus so that the surface on which the first electrode 101 was formed faced downward. Onto the first electrode 101, N-(biphenyl-2-yl)-N-(9,9-dimethylfluorene-2-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: oFBiSF(2)) represented by the above structural formula (i) and a material (OCHD-003) having an electron-accepting property with a molecular weight of 672 and containing fluorine were co-deposited at a weight ratio of 1:0.03 (= oFBiSF(2):OCHD-003) to a thickness of 10 nm by vapor deposition to form a hole injection layer 111.

[0483] Onto the hole injection layer 111, oFBiSF(2) was deposited to a thickness of 150 nm to form a first hole transport layer.

[0484] Subsequently, onto the first hole transport layer, 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) represented by the above structural formula (iii), and a material OCPG-006 that emits red phosphorescence were co-deposited at a weight ratio of 0.7:0.3:0.05 (= 11mDBtBPPnfpr:PCBBiF:OCPG-006) to a thickness of 40 nm by vapor deposition to form a first light-emitting layer.

[0485] After that, 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) was deposited to a thickness of 10 nm to form a first electron transport layer.

[0486] After the formation of the first electron transport layer, 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P) represented by the above structural formula (v) as a second organic compound containing a phenanthroline skeleton and lithium oxide (Li2O) were co-evaporated at a weight ratio of 1:0.02 (= mPPhen2P:Li2O) by 5 nm to form a first layer. Copper phthalocyanine (abbreviation: CuPc) represented by the above structural formula (vii) was evaporated to a thickness of 2 nm to form a third layer. Further, oFBiSF(2) and OCHD-003 were co-evaporated at a weight ratio of 1:0.15 (= oFBiSF(2):OCHD-003) by 10 nm to form a second layer, thereby forming an intermediate layer.

[0487] On the intermediate layer, 65 nm of oFBiSF(2) was evaporated to form a second hole transport layer.

[0488] On the second hole transport layer, 11mDBtBPPnfpr, PCBBiF, and OCPG-006 were co-evaporated at a weight ratio of 0.7:0.3:0.05 (= 11mDBtBPPnfpr:PCBBiF:OCPG-006) by 40 nm to form a second light-emitting layer.

[0489] Thereafter, 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) was formed into a film with a thickness of 10 nm. 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-hydroxyquinolinate (abbreviation: Liq) represented by the above structural formula (x) were co-evaporated at a weight ratio of 1:1 (= TznP2N:Liq) by 25 nm to form a second electron transport layer.

[0490] Thereafter, Liq was vapor-deposited to a film thickness of 1 nm, and silver (Ag) and magnesium (Mg) were co-vapor-deposited to a film thickness of 15 nm at a volume ratio of 1:0.1 to form the second electrode 102. Further, on the second electrode 102, 4,4’,4’’-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II) represented by the above structural formula (xi) was formed into a 70-nm film as a cap layer to improve the light extraction efficiency.

[0491] Subsequently, in a glove box under a nitrogen atmosphere, an operation of sealing with a glass substrate so that the light-emitting device is not exposed to the atmosphere (applying a UV curable sealing material around the element, irradiating only the sealing material with UV so as not to irradiate the light-emitting device, and heat treatment at 80 °C for 1 hour under atmospheric pressure) was performed to form the light-emitting device R1.

[0492] (Method for manufacturing the comparative light-emitting device R1) The comparative light-emitting device R1 was manufactured in the same manner as the light-emitting device R1, except that the second hole transport layer in the light-emitting device R1 was formed to a film thickness of 75 nm, and the second electron transport layer was formed by co-vapor-depositing 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) and Liq at a weight ratio of 1:1 (= 6BP-4Cz2PPm:Liq) to a thickness of 25 nm.

[0493] (Method for manufacturing the light-emitting device G1) The light-emitting device G1 was fabricated in the same manner as the light-emitting device R1, except that the film thickness of the first hole transport layer in the light-emitting device R1 was formed to be 80 nm, the film thickness of the second hole transport layer was formed to be 50 nm, and the first light-emitting layer and the second light-emitting layer were co-evaporated such that 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenz[c,g]carbazole (abbreviation: cgDBCzPA) represented by the above structural formula (xii) and 9,10-diphenyl-2-[N-phenyl-N-(9-phenyl-carbazol-3-yl)-amino]-anthracene (abbreviation: 2PCAPA) represented by the above structural formula (xiii) had a weight ratio of 1:0.05 (= cgDBCzPA:2PCAPA).

[0494] (Method for fabricating the comparative light-emitting device G1) The comparative light-emitting device G1 was fabricated in the same manner as the light-emitting device G1, except that the second hole transport layer in the light-emitting device G1 was formed to have a film thickness of 60 nm, and the second electron transport layer was formed by co-evaporating 6BP-4Cz2PPm and Liq in a weight ratio of 1:1 (= 6BP-4Cz2PPm:Liq) for 25 nm.

[0495] (Method for fabricating the light-emitting device B1) The light-emitting device B1 was fabricated in the same manner as the light-emitting device R1, except that the film thickness of the first hole transport layer in the light-emitting device R1 was formed to be 45 nm, the film thickness of the second hole transport layer was formed to be 45 nm, and the first light-emitting layer and the second light-emitting layer were co-evaporated such 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) had a weight ratio of 1:0.015 (= αN-βNPAnth:3,10PCA2Nbf(IV)-02) for 25 nm.

[0496] (Method for fabricating the comparative light-emitting device B1) The comparative light-emitting device B1 was fabricated in the same manner as the light-emitting device B1, except that the second hole transport layer in the light-emitting device B1 was formed to have a film thickness of 55 nm, and the second electron transport layer was formed by co-evaporating 25 nm of 6BP-4Cz2PPm and Liq at a weight ratio of 1:1 (= 6BP-4Cz2PPm:Liq).

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

[0498] [Table 1]

[0499] [Table 2]

[0500] [Table 3]

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

[0502] Note that the blue index (BI) is a value obtained by further dividing the current efficiency (cd / A) by the y value of the CIE(x,y) chromaticity, and is one of the indices representing the emission characteristics of blue light emission. In blue light emission, the smaller the chromaticity y value, the higher the color purity of the light emission tends to be. By using blue light emission with a small chromaticity y value and high color purity, it becomes possible to represent blue in a wide chromaticity range in a display. Since the luminance of blue required to represent white in the display decreases, an effect of reducing the power consumption of the display can be obtained. Therefore, BI, which is the current efficiency considering the chromaticity y value as one of the indices of blue purity, may be suitably used as a means for representing the efficiency of blue light emission. It can be said that the higher the BI of a light-emitting device, the better the efficiency as a blue light-emitting device used in a display.

[0503] Also, the main characteristics of the light-emitting device R1 and the comparative light-emitting device R1 near 1000 cd / m 2 are shown in Table 4, the main characteristics of the light-emitting device G1 and the comparative light-emitting device G1 near 1000 cd / m 2 are shown in Table 5, and the main characteristics of the light-emitting device B1 and the comparative light-emitting device B1 near 1000 cd / m 2 are shown in Table 6. Note that for the measurement of luminance, CIE chromaticity, and electroluminescence spectrum, a spectro-radiometer (Topcon Corporation, SR-UL1R) was used and the measurement was performed at room temperature.

[0504]

Table 4

[0505] From FIGS. 24 to 27 and Table 4, it was found that red light emission with a peak wavelength of 625 nm in the electroluminescence spectrum can be obtained from both the light-emitting device R1 and the comparative light-emitting device R1. Also, both the light-emitting device R1 and the comparative light-emitting device R1 are light-emitting devices with good current efficiency. However, since the driving voltage of the light-emitting device R1 is lower than that of the comparative light-emitting device R1, the power consumption is low, and it was found that the light-emitting device has good characteristics with high power efficiency. Thus, it was found that the light-emitting device R1 of one embodiment of the present invention is a tandem-type light-emitting device having good characteristics.

[0506]

Table 5

[0507] From FIGS. 28 to 31 and Table 5, it was found that green light emission with a peak wavelength of 532 nm in the electroluminescence spectrum can be obtained from both the light-emitting device G1 and the comparative light-emitting device G1. Also, both the light-emitting device G1 and the comparative light-emitting device G1 are light-emitting devices with good current efficiency. However, since the driving voltage of the light-emitting device G1 is lower than that of the comparative light-emitting device G1, the power consumption is low, and it was found that the light-emitting device has good characteristics. Thus, it was found that the light-emitting device G1 of one embodiment of the present invention is a tandem-type light-emitting device having good characteristics.

[0508]

Table 6

[0509] From FIGS. 32 to 36 and Table 6, it was found that blue light emission with peak wavelengths of 454 nm and 457 nm was obtained from the light-emitting device B1 and the comparative light-emitting device B1. Also, both the light-emitting device B1 and the comparative light-emitting device B1 are light-emitting devices with good current efficiency. However, since the driving voltage of the light-emitting device B1 is lower than that of the comparative light-emitting device B1, the power consumption is low, and it was found that the light-emitting device B1 has good characteristics. Further, it was found that the light-emitting device B1 is a light-emitting device with a good blue index. Thus, it was found that the light-emitting device B1 of one aspect of the present invention is a tandem-type light-emitting device having good characteristics as a light-emitting device constituting the blue sub-pixel of the display device. Also, the light-emitting device B1 has a particularly practical luminance of 500 cd / cm 2 It was found that it is a light-emitting device with good characteristics as described above.

[0510] Here, the second electron transport layer of the light-emitting device R1, the light-emitting device G1, and the light-emitting device B1 is configured to contain the same material (the first organic compound containing a triazine skeleton). Thus, in the light-emitting device of one aspect of the present invention, even if the second electron transport layer is made of the same material in light-emitting devices of different emission colors, it is possible to make each light-emitting device a light-emitting device having good characteristics.

[0511] Next, an example display device using 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 a comparative example display device using the comparative light-emitting device R1, the comparative light-emitting device G1, and the comparative light-emitting device B1 respectively were assumed, and the power consumption of the display unit (excluding the power consumption of driving transistors and driving circuits, etc.) was estimated. Note that both display devices are display devices adopting a coating method because each light-emitting device to be used is a tandem-type light-emitting device, and the light-emitting center substances contained in the plurality of light-emitting layers of each light-emitting device are the same substance.

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

[0513]

Table 7

[0514] First, in the display device under the above conditions, when the entire surface emits light, white light with chromaticity (x, y) = (0.31, 0.33) in the CIE1931 chromaticity coordinates has a luminance of 1000 cd / m 2 The luminance (effective luminance) of the light-emitting device obtained thereby was determined for each color.

[0515] Subsequently, taking into account the aperture ratio, the luminance (true luminance) required to obtain the determined effective luminance was calculated for each color light-emitting device. The true luminance is the luminance at which each light-emitting device actually emits light when the display device emits light over the entire surface with white light having chromaticity (x, y) = (0.31, 0.33) in the CIE1931 chromaticity coordinates and has an effective luminance of 1000 cd / m 2 Since the overall aperture ratio of the display device for which the trial calculation is performed is 30% and 10% for each emission color, the true luminance is approximately 10 times the effective luminance.

[0516] From the measurement results of each light-emitting device shown above, the current density and voltage for causing the light-emitting device to emit light at that luminance can be determined using the true luminance. That is, in the display device under the above conditions, when the entire surface emits light, white light with chromaticity (x, y) = (0.31, 0.33) in the CIE1931 chromaticity coordinates has a luminance of 1000 cd / m 2 The current density and voltage of the light-emitting device obtained thereby can be determined.

[0517] Power consumption is obtained by multiplying the current amount by the voltage. The current amount is obtained by multiplying the current density by the panel area and the aperture ratio. The size of the trial-calculated display device is 5 inches diagonal, with an aspect ratio of 16:9, and the panel area is 68.9 cm 2Since the aperture ratio of each color light-emitting device is 10%, the current amount can be calculated by multiplying the current density calculated in the previous paragraph by these, and further, by applying the voltage obtained in the previous paragraph, the power consumption of the light-emitting device for each emission color can be calculated. By calculating the power consumption for each color of the light-emitting device and adding them together, the power consumption of the entire display section in the display device (excluding the power consumption of the driving transistor and the driving circuit, etc.) can be obtained.

[0518] Table 8 shows the results of calculating the power consumption for a display device of an embodiment assuming the use of light-emitting device R1, light-emitting device G1, and light-emitting device B1, and Table 9 shows the results of calculating the power consumption for a display device of a 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

[0520]

Table 9

[0521] From Tables 8 and 9, it was found that the display device of the embodiment has higher current efficiency in white light emission and a lower driving voltage than the display device of the comparative example. Also, it was found that the display device of the embodiment has a smaller power consumption than the display device of the comparative example.

[0522] As described above, a display device using a tandem-type light-emitting device in which the second electron transport layer has a first organic compound containing a triazine skeleton, the intermediate layer has 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 spectrum of the light emitted from the plurality of light-emitting layers is 30 nm or less, was found to be a display device having good characteristics with low power consumption.

Explanation of Reference Numerals

[0523] 100A indicating device 100B indicating device 100C indicating device 100D indicating device 100E indicating device 100 indicating device 101 First electrode 101a First electrode 101b First electrode 101c First electrode 101B First electrode 101G First electrode 101R First electrode 101W First electrode 102 Second electrode 103B Organic compound layer 103Bf Organic compound film 103G Organic compound layer 103Gf Organic compound film 103R Organic compound layer 103Rf Organic compound film 103 Organic compound layer 103a Organic compound layer 103b Organic compound layer 103c Organic compound layer 104 Common layer 110B Sub-pixel 110G Sub-pixel 110R Sub-pixel 110W Sub-pixel 110 Sub-pixel 111 Hole injection layer 111a Hole injection layer 111b Hole injection layer 111c Hole injection layer 112B Conductive layer 112R Conductive layer 112 Hole transport layer 113 Light-emitting layer 114 Electron transport layer 114a_1a Electron transport layer 114_2b Electron transport layer 114c_1a Electron transport layer 114b_2b Electron transport layer 114c_2b Electron transport layer 114a_2a Electron transport layer 114a_2b Electron transport layer 114b_1a Electron transport layer 114a_1b Electron transport layer 114b_1b Electron transport layer 114c_1b Electron transport layer 114c_2a Electron transport layer 114_2a Electron transport layer 114b_2a Electron transport layer 116 Intermediate layer 117 Second layer 118 Third layer 119 First layer 120 Substrate 122 Resin layer 125f Inorganic insulating film 125 Inorganic insulating layer 126B Conductive layer 126R Conductive layer 127a Insulating layer 127f Insulating film 127 Insulating layer 128 Layer 129B Conductive layer 129R Conductive layer 130B Light-emitting device 130G Light-emitting device 130R Light-emitting device 130 Light-emitting device 130a Light-emitting device 130b Light-emitting device 130c Light-emitting device 131 Protection layer 132B Coloring layer 132G Coloring layer 132R Coloring layer 140 Connection part 141 Region 142 Adhesive layer 151B Conductive layer 151C Conductive layer 151f Conductive film 151G Conductive layer 151R Conductive Layer 151 Conductive Layer 152B Conductive Layer 152C Conductive Layer 152f Conductive Film 152G Conductive Layer 152R Conductive Layer 152 Conductive Layer 153 Insulating Layer 155 Common Electrode 156B Insulating Layer 156C Insulating Layer 156f Insulating Film 156G Insulating Layer 156R Insulating Layer 156 Insulating Layer 157 Light-Shielding Layer 158B Sacrificial Layer 158Bf Sacrificial Film 158G Sacrificial Layer 158Gf Sacrificial Film 158R Sacrificial Layer 158Rf Sacrificial Film 159B Mask Layer 159Bf Mask Film 159G Mask Layer 159Gf Mask Film 159R Mask Layer 159Rf Mask Film 166 Conductive Layer 171 Insulating Layer 172 Conductive Layer 173 Insulating Layer 174 Insulating Layer 175 Insulating Layer 176 Plug 177 Pixel Section 178 Pixel 178a Pixel 178b Pixel 179 Conductive Layer 190B Resist Mask 190G Resist Mask 190R Resist Mask 191 Resist Mask 201 Transistor 204 Connection Part 205 Transistor 211 Insulating layer 213 Insulating layer 214 Insulating layer 215 Insulating layer 221 Conductive layer 222a Conductive layer 222b Conductive layer 223 Conductive layer 224B Conductive layer 224C Conductive layer 224G Conductive layer 224R Conductive layer 231 Semiconductor layer 240 Capacitance 241 Conductive layer 242 Connection layer 243 Insulating layer 245 Conductive layer 254 Insulating layer 255 Insulating layer 256 Plug 261 Insulating layer 271 Plug 280 Display module 281 Display unit 282 Circuit unit 283a Pixel circuit 283 Pixel circuit unit 284a Pixel 284 Pixel unit 285 Terminal unit 286 Wiring unit 290 FPC 291 Substrate 292 Substrate 301 Substrate 310 Transistor 311 Conductive layer 312 Low-resistance region 313 Insulating layer 314 Insulating layer 315 Element isolation layer 317 Light-shielding layer 351 Substrate 352 Substrate 353 FPC 354 IC 355 Wiring 356 circuit 501 First light-emitting unit 501a First light-emitting unit 501b First light-emitting unit 501c First light-emitting unit 502 Second light-emitting unit 502a Second light-emitting unit 502b Second light-emitting unit 502c Second light-emitting unit 601 Source line drive circuit, drive circuit section 602 Pixel section 603 Gate line drive circuit 604 Sealing substrate 605 Sealing material 607 Space 608 Wiring harness 610 Element substrate 611 Switching FET 612 Current control FET 613 First electrode 614 Insulator 616 Organic compound layer 617 Second electrode 618 Light-emitting device 623 FET 700A Electronic device 700B Electronic device 721 Housing 723 Mounting part 727 Earphone part 750 Earphone 751 Display panel 753 Optical member 756 Display area 757 Frame 758 Nose pad 800A Electronic device 800B Electronic device 820 Display unit 821 Housing 822 Communication part 823 Mounting part 824 Control part 825 Imaging part 827 Earphone part 832 Lens 6500 Electronic device 6501 Housing 6502 Display unit 6503 Power button 6504 Button 6505 Speaker 6506 Microphone 6507 Camera 6508 Light source 6510 Protective member 6511 Display panel 6512 Optical member 6513 Touch sensor panel 6515 FPC 6516 IC 6517 Printed circuit board 6518 Battery 7000 Display unit 7100 Television apparatus 7151 Remote control operation unit 7171 Housing 7173 Stand 7200 Notebook personal computer 7211 Housing 7212 Keyboard 7213 Pointing device 7214 External connection port 7300 Digital signage 7301 Housing 7303 Speaker 7311 Information terminal device 7400 Digital signage 7401 Column 7411 Information terminal device 9000 Housing 9001 Display unit 9002 Camera 9003 Speaker 9005 Operation key 9006 Connection terminal 9007 Sensor 9008 Microphone 9050 Icon 9051 Information 9052 Information 9053 Information 9054 Information 9055 Hinge 9171 Portable Information Terminal 9172 Portable Information Terminal 9173 Tablet Terminal 9200 Portable Information Terminal 9201 Portable Information Terminal

Claims

1. a first electrode, a second electrode, an intermediate layer, a first light-emitting layer, a second light-emitting layer, a first electron transport layer, a second electron transport layer, and a light-emitting device having the same, wherein 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 a laminated structure including at least a second a electron transport layer and a second b electron transport layer, the second b electron transport layer is located between the second a electron transport layer and the second electrode, the intermediate layer has a mixed layer of a second organic compound having a phenanthroline skeleton and lithium or a lithium compound, the first light-emitting layer has a first light-emitting central substance, the second light-emitting layer has a second light-emitting central substance, the difference between the maximum peak wavelength in the emission spectrum of the first light-emitting central substance and the maximum peak wavelength in the emission spectrum of the second light-emitting central substance is 30 nm or less, the first light-emitting layer and the second light-emitting layer are light-emitting layers different from the light-emitting layers of at least one of a plurality of other light-emitting devices adjacent to the light-emitting device.

2. a first electrode, a second electrode, an intermediate layer, a first light-emitting layer, a second light-emitting layer, a first electron transport layer, a second electron transport layer, and a light-emitting device having the same, wherein 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 a laminated structure including at least a second a electron transport layer and a second b electron transport layer, the second b electron transport layer is located between the second a electron transport layer and the second electrode, the second b electron transport layer has a first organic compound containing a triazine skeleton, the intermediate layer has a mixed layer of a second organic compound having a phenanthroline skeleton and lithium or a lithium compound, The first light-emitting layer has a first light-emitting center substance, The second light-emitting layer has a second light-emitting center substance, The difference between the maximum peak wavelength in the emission spectrum of the first light-emitting center substance and the maximum peak wavelength in the emission spectrum of the second light-emitting center substance is 30 nm or less, The first light-emitting layer and the second light-emitting layer are light-emitting devices that are different from the light-emitting layers of at least one of the plurality of other light-emitting devices adjacent to the light-emitting device.

3. A first electrode, A second electrode, An intermediate layer, A first light-emitting layer, A second light-emitting layer, A first electron transport layer, A second electron transport layer, which is a light-emitting device having: 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 a stacked structure of at least a second a electron transport layer and a second b electron transport layer, The second b electron transport layer is located between the second a electron transport layer and the second electrode, The second b 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 having a phenanthroline skeleton, The first light-emitting layer has a first light-emitting center substance, The second light-emitting layer has a second light-emitting center substance, The difference between the maximum peak wavelength in the emission spectrum of the first light-emitting center substance and the maximum peak wavelength in the emission spectrum of the second light-emitting center substance is 30 nm or less, The first light-emitting layer and the second light-emitting layer are light-emitting devices that are different from the light-emitting layers of at least one of the plurality of other light-emitting devices adjacent to the light-emitting device.

4. The light-emitting device according to claim 3, wherein the first organic compound and the third organic compound are the same organic compound.

5. According to claim 3, The light-emitting device in which the intermediate layer has lithium or a lithium compound.

6. According to claim 5, An organic light-emitting device in which the intermediate layer has a mixed layer of the second organic compound and the lithium or lithium compound.

7. In any one of Claims 1 to 6, An organic light-emitting device in which the second electron transport layer has a lithium or lithium compound.

8. In any one of Claims 1 to 6, An organic light-emitting device in which the first light-emitting center substance and the second light-emitting center substance are the same substance.

9. In any one of Claims 1 to 6, An organic light-emitting device in which the intermediate layer has a first layer containing the second organic compound.

10. In Claim 9, The intermediate layer further has a second layer, An organic light-emitting device in which the second layer is located between the first layer and the second light-emitting layer.

11. In Claim 10, An organic light-emitting device in which the second layer contains a fourth organic compound having hole transporting properties.

12. In Claim 11, An organic light-emitting device in which the second layer contains an organic compound having at least one of a halogen group and a cyano group.

13. In any one of Claims 1 to 6, The first electron transport layer has a laminated structure of at least a first a electron transport layer and a first b electron transport layer, An organic light-emitting device in which the first b electron transport layer is located between the first a electron transport layer and the intermediate layer.

14. In Claim 13, An organic light-emitting device in which the first b electron transport layer has a third organic compound containing a triazine skeleton.

15. A display device having a light-emitting device A and a light-emitting device B, The light-emitting device A and the light-emitting device B are adjacent to each other, The light-emitting device A includes: A first electrode A, A second electrode A, An intermediate layer A, A first light-emitting layer A, A second light-emitting layer A, A first electron transport layer A, A second electron transport layer A, The intermediate layer A is located between the first electrode A and the second electrode A, The first light-emitting layer A is located between the first electrode A and the intermediate layer A, The second light-emitting layer A is located between the intermediate layer A and the second electrode A, The first electron transport layer A is located between the first light-emitting layer A and the intermediate layer A, The second electron transport layer A is located between the second light-emitting layer A and the second electrode A, The second electron transport layer A has a laminated structure of at least a second a electron transport layer A and a second b electron transport layer A, The second electron transport layer A is located between the second electron transport layer A and the second electrode A. The light-emitting device B has a first electrode B, a second electrode B, an intermediate layer B, a first light-emitting layer B, a second light-emitting layer B, a first electron transport layer B, and a second electron transport layer B. The intermediate layer B is located between the first electrode B and the second electrode B. The first light-emitting layer B is located between the first electrode B and the intermediate layer B. The second light-emitting layer B is located between the intermediate layer B and the second electrode B. The first electron transport layer B is located between the first light-emitting layer B and the intermediate layer B. The second electron transport layer B is located between the second light-emitting layer B and the second electrode B. The second electron transport layer B has at least a laminated structure of a second a electron transport layer B and a second b electron transport layer B. The second b electron transport layer B is located between the second a electron transport layer B and the second electrode B. The second b electron transport layer A and the second b electron transport layer B are made of the same material. The intermediate layer A and the intermediate layer B have a second organic compound having a phenanthroline skeleton and lithium or a lithium compound. The first light-emitting layer A has a first light-emitting central substance. The second light-emitting layer A has a second light-emitting central substance. The first light-emitting layer B has a third light-emitting central substance. The second light-emitting layer B has a fourth light-emitting central substance. The difference between the maximum peak wavelength in the emission spectrum of the first light-emitting central substance and the maximum peak wavelength in the emission spectrum of the second light-emitting central substance is 30 nm or less. The difference between the maximum peak wavelength in the emission spectrum of the third light-emitting central substance and the maximum peak wavelength in the emission spectrum of the fourth light-emitting central substance is 30 nm or less. A display device in which the first light-emitting layer A and the first light-emitting layer B, and the second light-emitting layer A and the second light-emitting layer B are different light-emitting layers respectively.

16. A display device having a light-emitting device A and a light-emitting device B, wherein the light-emitting device A and the light-emitting device B are adjacent to each other, and the light-emitting device A has a first electrode A, a second electrode, an intermediate layer A, a first light-emitting layer A, a second light-emitting layer A, a first electron transport layer A, and a second electron transport layer A. The intermediate layer A is located between the first electrode A and the second electrode A. The first light-emitting layer A is located between the first electrode A and the intermediate layer A, The second light-emitting layer A is located between the intermediate layer A and the second electrode A, The first electron transport layer A is located between the first light-emitting layer A and the intermediate layer A, The second electron transport layer A is located between the second light-emitting layer A and the second electrode A, The second electron transport layer A has a laminated structure of at least a second a electron transport layer A and a second b electron transport layer A, The second b electron transport layer A is located between the second a electron transport layer A and the second electrode A, The light-emitting device B, A first electrode B, A second electrode B, An intermediate layer B, A first light-emitting layer B, A second light-emitting layer B, A first electron transport layer B, And a second electron transport layer B, The intermediate layer B is located between the first electrode B and the second electrode B, The first light-emitting layer B is located between the first electrode B and the intermediate layer B, The second light-emitting layer B is located between the intermediate layer B and the second electrode B, The first electron transport layer B is located between the first light-emitting layer B and the intermediate layer B, The second electron transport layer B is located between the second light-emitting layer B and the second electrode B, The second electron transport layer B has a laminated structure of at least a second a electron transport layer B and a second b electron transport layer B, The second b electron transport layer B is located between the second a electron transport layer B and the second electrode B, The second electron transport layer A and the second electron transport layer B are continuous layers, The intermediate layer A and the intermediate layer B have a second organic compound having a phenanthroline skeleton and lithium or a lithium compound, The first light-emitting layer A has a first light-emitting central substance, The second light-emitting layer A has a second light-emitting central substance, The first light-emitting layer B has a third light-emitting central substance, The second light-emitting layer B has a fourth light-emitting central substance, The difference between the maximum peak wavelength in the emission spectrum of the first light-emitting central substance and the maximum peak wavelength in the emission spectrum of the second light-emitting central substance is 30 nm or less, The difference between the maximum peak wavelength in the emission spectrum of the third light-emitting central substance and the maximum peak wavelength in the emission spectrum of the fourth light-emitting central substance is 30 nm or less, A display device in which the first light-emitting layer A and the first light-emitting layer B, and the second light-emitting layer A and the second light-emitting layer B are different light-emitting layers respectively.

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