Light-emitting device

Abstract

The present invention provides a light-emitting device having good reliability. Provided is a light-emitting device comprising a first electrode, a second electrode, a light-emitting layer, and a first layer, the light-emitting layer being located between the first electrode and the second electrode, the first layer being in contact with the light-emitting layer, the light-emitting layer having a fluorescent light-emitting substance, a first organic compound, and a second organic compound, the first layer having a third organic compound, the first organic compound having a first polycyclic hydrocarbon, the second organic compound having a second polycyclic hydrocarbon, and the third organic compound having an amine skeleton and a first polycyclic heteroaromatic ring.

Description

Light-emitting devices

[0001] One embodiment of the present invention relates to an organic compound, an organic semiconductor element, a light-emitting device, a photodiode sensor, a display module, a lighting module, a display device, an electronic device, a lighting device, and an electronic device. Note that one embodiment of the present invention is not limited to the above technical field. The technical field of one embodiment of the invention disclosed in this specification etc. relates to an object, a method, or a manufacturing method. Alternatively, one embodiment of the present invention relates to a process, a machine, manufacture, or a composition of matter. Therefore, more specifically, examples of the technical field of one embodiment 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 memory device, an imaging device, a driving method thereof, or a manufacturing method thereof.

[0002] Light-emitting devices (also called organic EL elements) that utilize electroluminescence (EL) using organic compounds are becoming increasingly practical. The basic structure of these light-emitting devices is a pair of electrodes sandwiching an organic compound layer containing a light-emitting material. By applying a voltage to this device, carriers are injected, and the recombination energy of the carriers is utilized to emit light from the light-emitting material.

[0003] Since light-emitting devices are self-luminous, display devices using these light-emitting devices as pixels have higher visibility than liquid crystal display devices and do not require backlighting. Another major advantage of display devices using such light-emitting devices is that they can be fabricated to be thin and lightweight. Another feature is their extremely fast response speed.

[0004] Furthermore, these light-emitting devices can have a continuous, planar light-emitting layer, which allows them to emit light in a planar manner. This is a feature that is difficult to obtain with point light sources such as incandescent lamps and LEDs, or linear light sources such as fluorescent lamps, making them highly useful as planar light sources for lighting applications.

[0005] Display devices and lighting devices using such light-emitting devices are suitable for a variety of electronic devices, but research and development is ongoing to find light-emitting devices with even better characteristics.

[0006] Patent Document 1 discloses a light-emitting device in which a light-emitting layer contains a first compound, a second compound, and a third compound, which are fluorescent light-emitting materials.

[0007] International Publication No. 2017 / 010438

[0008] An object of one embodiment of the present invention is to provide a light-emitting device with good characteristics. Alternatively, an object of one embodiment of the present invention is to provide a light-emitting device with good reliability. Alternatively, an object of another embodiment of the present invention is to provide a light-emitting device with little change in efficiency relative to luminance. Alternatively, an object of one embodiment of the present invention is to provide a light-emitting device with which a display device with good display quality can be fabricated. Alternatively, an object of one embodiment of the present invention is to provide a light-emitting device with low driving voltage. Alternatively, an object of one embodiment of the present invention is to provide a light-emitting device with good reliability and low driving voltage.

[0009] Another object of one embodiment of the present invention is to provide a light-emitting device that can provide a display device with good characteristics. Another object of one embodiment of the present invention is to provide a light-emitting device that can provide a display device with good reliability. Another object of one embodiment of the present invention is to provide a display device with low driving voltage. Another object of one embodiment of the present invention is to provide a light-emitting device that can provide a display device with low driving voltage and good reliability. Another object of one embodiment of the present invention is to provide a display device with good display quality. Another object of one embodiment of the present invention is to provide a display device with good display quality and good reliability.

[0010] Another 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 that consumes little power, or to provide any one of an electronic device and a lighting device that has high reliability.

[0011] The present invention is intended to solve any one of the above problems.

[0012] One embodiment of the present invention is a light-emitting device including a first electrode, a second electrode, a light-emitting layer, and a first layer. The light-emitting layer is located between the first electrode and the second electrode. The first layer is in contact with the light-emitting layer. The light-emitting layer includes a fluorescent material, a first organic compound, and a second organic compound. The first layer includes a third organic compound. The first organic compound includes a first polycyclic hydrocarbon. The second organic compound includes a second polycyclic hydrocarbon. The third organic compound includes an amine skeleton and a first polycyclic heteroaromatic ring.

[0013] Another embodiment of the present invention is a light-emitting device having the above structure, in which the first polycyclic hydrocarbon is a substituted or unsubstituted aromatic hydrocarbon having 6 to 22 carbon atoms, and the second polycyclic hydrocarbon is a substituted or unsubstituted aromatic hydrocarbon having 6 to 22 carbon atoms.

[0014] Another embodiment of the present invention is a light-emitting device having the above structure, in which the first polycyclic hydrocarbon and the second polycyclic hydrocarbon each have an anthracene skeleton.

[0015] Another embodiment of the present invention is a light-emitting device having the above structure, in which the first polycyclic hydrocarbon and the second polycyclic hydrocarbon are substituted or unsubstituted anthracenyl groups.

[0016] Another embodiment of the present invention is a light-emitting device having the above structure, in which the first polycyclic hydrocarbon and the second polycyclic hydrocarbon are the same.

[0017] Another embodiment of the present invention is a light-emitting device having the above structure, in which the first polycyclic hydrocarbon and the second polycyclic hydrocarbon are anthracenyl groups.

[0018] Another embodiment of the present invention is a light-emitting device having the above structure, in which the first organic compound is an aromatic hydrocarbon and the second organic compound further includes a second polycyclic heteroaromatic ring.

[0019] Another embodiment of the present invention is a light-emitting device having any of the above structures, in which both the first organic compound and the second organic compound are aromatic hydrocarbons.

[0020] Another embodiment of the present invention is light emission in which one or both of the first organic compound and the second organic compound in the above structure are deuterated.

[0021] Another embodiment of the present invention is a light-emitting device having the above structure, in which the first organic compound and the second organic compound are each independently an organic compound represented by General Formula (G0) below:

[0022]

[0023] However, in general formula (G0), R １０１ ~R １１０ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted branched or linear alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 22 carbon atoms, and a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms, and the first organic compound and the second organic compound are different organic compounds.

[0024] Another embodiment of the present invention is a light-emitting device having the above structure, in which the first organic compound is an organic compound represented by General Formula (G1) below.

[0025]

[0026] In the above general formula (G1), R １ ~R １０ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted branched or linear alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 22 carbon atoms.

[0027] Another embodiment of the present invention is a light-emitting device having the above structure, in which the second organic compound is an organic compound represented by General Formula (G2) below.

[0028]

[0029] In general formula (G2), R １１ ~R ２０ each independently represents hydrogen (including deuterium), a substituted or unsubstituted branched or linear alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 22 carbon atoms, or a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms; R １１ ~R ２０ At least one of the groups represents a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms.

[0030] Another embodiment of the present invention is a light-emitting device having the above structure, in which the first organic compound and the second organic compound are each independently an organic compound represented by General Formula (G1) below:

[0031]

[0032] However, in general formula (G1), R １ ~R １０ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted branched or linear alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 22 carbon atoms, and the first organic compound and the second organic compound are different organic compounds.

[0033] Another embodiment of the present invention is a light-emitting device having the above structure, in which the first organic compound is an organic compound represented by General Formula (G1) below, and the second organic compound is an organic compound represented by General Formula (G2) below:

[0034]

[0035] In general formula (G1), R １ ~R １０ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted branched or linear alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 22 carbon atoms.

[0036]

[0037] In general formula (G2), R １１ ~R ２０ each independently represents hydrogen (including deuterium), a substituted or unsubstituted branched or linear alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 22 carbon atoms, or a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms; R １１ ~R ２０ At least one of the groups represents a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms.

[0038] Another embodiment of the present invention is a light-emitting device having the above structure, in which the third organic compound is an organic compound represented by General Formula (G3) below.

[0039]

[0040] In general formula (G3), Ar １ , Ar ３ and Ar ５ represents a substituted or unsubstituted arylene group having 6 to 22 carbon atoms or a substituted or unsubstituted heteroarylene group having 1 to 30 carbon atoms; Ar ２ and Ar ４ represents any one of a substituted or unsubstituted aryl group having 6 to 22 carbon atoms and a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms; n, m, and l represent an integer of 0 to 3; when n, m, and l are 2 or more, a plurality of Ar １ or Ar ３ or Ar ５ may be the same or different, and Ar ６ is represented by any one of the following general formulas (g3-1) to (g3-4).

[0041]

[0042] In the general formulas (g3-1) to (g3-4), X represents an oxygen atom, a sulfur atom, or a nitrogen atom. When X is a nitrogen atom, the nitrogen atom has any one of a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, a linear or branched alkyl group having 1 to 6 carbon atoms, and a cycloalkyl group having 3 to 10 carbon atoms. ２１ ~R ２８ , and R ３０ ~R ３５ and R ４０ ~R ４５ and R ５０ ~R ５５ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted branched or linear alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 22 carbon atoms, and a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms; R ２１ ~R ２８ One of the following, or R ３０ ~R ３５ One of the following, or R ４０ ~R ４５ One of the following, or R ５０ ~R ５５ One of them is Ar in general formula (G3). ５ Or it represents a bond to nitrogen.

[0043] Another embodiment of the present invention is a display device including any of the above light-emitting devices.

[0044] Another embodiment of the present invention is an electronic device including any of the above light-emitting devices and a sensor, an operation button, a speaker, or a microphone.

[0045] Another embodiment of the present invention is a lighting device including the above-described light-emitting device and a housing.

[0046] According to one embodiment of the present invention, a light-emitting device with high emission efficiency can be provided. According to another embodiment of the present invention, a light-emitting device with high reliability can be provided. According to another embodiment of the present invention, a light-emitting device with small change in efficiency relative to luminance can be provided. According to one embodiment of the present invention, a light-emitting device with which a display device with high display quality can be fabricated can be provided. According to another embodiment of the present invention, a display device, an electronic device, or a lighting device with low power consumption can be provided. According to another embodiment of the present invention, a display device with high display quality can be provided. According to another embodiment of the present invention, a display device with high display quality and high reliability can be provided.

[0047] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. Note that effects other than these will become apparent from the description in the specification, drawings, claims, etc., and it is possible to extract other effects from the description in the specification, drawings, claims, etc.

[0048] FIGS. 1A to 1C are schematic diagrams of a light-emitting device according to one embodiment of the present invention. FIGS. 2A and 2B are diagrams illustrating a display device according to one embodiment of the present invention. FIGS. 3A and 3B are diagrams illustrating a display device according to one embodiment of the present invention. FIGS. 4A to 4E are cross-sectional views illustrating an example of a manufacturing method of a display device. FIGS. 5A and 5B are cross-sectional views illustrating an example of a manufacturing method of a display device. FIGS. 6A to 6D are cross-sectional views illustrating an example of a manufacturing method of a display device. FIGS. 7A to 7C are cross-sectional views illustrating an example of a manufacturing method of a display device. FIGS. 8A to 8C are cross-sectional views illustrating an example of a manufacturing method of a display device. FIGS. 9A to 9C are cross-sectional views illustrating an example of a manufacturing method of a display device. FIGS. 10A and 10B are perspective views illustrating a structural example of a display module. FIGS. 11A and 11B are cross-sectional views illustrating a structural example of a display device. FIG. 12 is a perspective view illustrating a structural example of a display device. FIG. 13 is a cross-sectional view illustrating a structural example of a display device. FIG. 14 is a cross-sectional view illustrating a structural example of a display device. 15A, 15B, and 15C are cross-sectional views showing an example of the configuration of a display device. FIG. 16 is a cross-sectional view showing an example of the configuration of a display device. FIG. 17A, 17B, and 17C are cross-sectional views showing an example of the configuration of a display device. FIG. 18A, 18B, 18C, and 18D are diagrams explaining an example of a wearable device. FIG. 19A to 19F are diagrams showing an example of an electronic device. FIG. 20A to 20G are diagrams showing an example of an electronic device. FIG. 21 is a diagram showing the luminance-current density characteristics of light-emitting device 1, comparative light-emitting device 1-1, and comparative light-emitting device 1-2. FIG. 22 is a diagram showing the current efficiency-luminance characteristics of light-emitting device 1, comparative light-emitting device 1-1, and comparative light-emitting device 1-2. FIG. 23 is a diagram showing the current density-voltage characteristics of light-emitting device 1, comparative light-emitting device 1-1, and comparative light-emitting device 1-2. FIG. 24 is a diagram showing the external quantum efficiency-luminance characteristics of light-emitting device 1, comparative light-emitting device 1-1, and comparative light-emitting device 1-2. Fig. 25 is a graph showing electroluminescence spectra of light-emitting device 1, comparative light-emitting device 1-1, and comparative light-emitting device 1-2. Fig. 26 is a graph showing normalized luminance time change characteristics of light-emitting device 1, comparative light-emitting device 1-1, and comparative light-emitting device 1-2.FIG. 27 is a graph showing the luminance-current density characteristics of light-emitting device 2 and comparative light-emitting device 2. FIG. 28 is a graph showing the current efficiency-luminance characteristics of light-emitting device 2 and comparative light-emitting device 2. FIG. 29 is a graph showing the current density-voltage characteristics of light-emitting device 2 and comparative light-emitting device 2. FIG. 30 is a graph showing the external quantum efficiency-luminance characteristics of light-emitting device 2 and comparative light-emitting device 2. FIG. 31 is a graph showing the electroluminescence spectra of light-emitting device 2 and comparative light-emitting device 2. FIG. 32 is a graph showing the normalized luminance time change characteristics of light-emitting device 2 and comparative light-emitting device 2. FIG. 33 is a graph showing the luminance-current density characteristics of light-emitting device 3 and comparative light-emitting device 3. FIG. 34 is a graph showing the current efficiency-luminance characteristics of light-emitting device 3 and comparative light-emitting device 3. FIG. 35 is a graph showing the current density-voltage characteristics of light-emitting device 3 and comparative light-emitting device 3. FIG. 36 is a graph showing the external quantum efficiency-luminance characteristics of light-emitting device 3 and comparative light-emitting device 3. FIG. 37 is a graph showing the electroluminescence spectra of light-emitting device 3 and comparative light-emitting device 3. FIG. 38 is a graph showing the normalized luminance time characteristics of light-emitting device 3 and comparative light-emitting device 3. FIG. 39 is a graph showing the luminance-current density characteristics of light-emitting device 4 and comparative light-emitting device 4. FIG. 40 is a graph showing the current efficiency-luminance characteristics of light-emitting device 4 and comparative light-emitting device 4. FIG. 41 is a graph showing the current density-voltage characteristics of light-emitting device 4 and comparative light-emitting device 4. FIG. 42 is a graph showing the external quantum efficiency-luminance characteristics of light-emitting device 4 and comparative light-emitting device 4. FIG. 43 is a graph showing the electroluminescence spectra of light-emitting device 4 and comparative light-emitting device 4. FIG. 44 is a graph showing the normalized luminance time characteristics of light-emitting device 4 and comparative light-emitting device 4. FIG. 45 is a graph showing the luminance-current density characteristics of light-emitting device 5 and comparative light-emitting device 5. FIG. 46 is a graph showing the current efficiency-luminance characteristics of light-emitting device 5 and comparative light-emitting device 5. FIG. 47 is a graph showing the current density-voltage characteristics of light-emitting device 5 and comparative light-emitting device 5. FIG. 48 is a graph showing the external quantum efficiency-luminance characteristics of light-emitting device 5 and comparative light-emitting device 5. FIG. 49 shows electroluminescence spectra of Light-Emitting Device 5 and Comparative Light-Emitting Device 5.FIG. 50 is a graph showing the normalized luminance time change characteristics of the light-emitting device 5 and the comparative light-emitting device 5.

[0049] 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 it will be readily understood by those skilled in the art that various changes in form and details can be made without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the embodiments shown below.

[0050] In this specification, etc., a device fabricated using a metal mask or an FMM (fine metal mask, high-resolution metal mask) may be referred to as a device with an MM (metal mask) structure. In addition, in this specification, etc., a device fabricated without using a metal mask or an FMM may be referred to as a device with an MML (metal maskless) structure.

[0051] Furthermore, in this specification, the term "deuterated organic compound" refers to an organic compound in which, when focusing on hydrogen (including deuterium) present at a specific position in the organic compound, the proportion of the hydrogen (including deuterium) that is deuterium is greater than the natural abundance of deuterium. This proportion is preferably sufficiently greater than the natural abundance. In this case, "sufficiently" refers to, for example, 7.5% or more being deuterated. The deuteration of an organic compound can be confirmed by methods such as NMR and mass spectrometry.

[0052] In this specification, ordinal numbers such as "first" and "second" are used for convenience and do not limit the number of components or the order of the components. The order of the components includes, for example, the order of processes or the order of stacking. In other words, the ordinal numbers used in the embodiments of this specification may not match the ordinal numbers used in the claims. Furthermore, the ordinal numbers used in the examples of this specification may not match the ordinal numbers used in the claims. Furthermore, the ordinal numbers used in the embodiments of this specification may not match the ordinal numbers used in the examples of this specification.

[0053] In this specification and the like, a photoluminescence (PL) spectrum refers to a spectrum obtained in fluorometry by fixing the excitation wavelength of excitation light and measuring the wavelength of emitted light. It may also be referred to as an emission spectrum. The emission spectrum may contain a fluorescent component and a phosphorescent component. In this specification and the like, an emission spectrum consisting of a fluorescent component may be particularly referred to as a fluorescence spectrum, and an emission spectrum consisting of a phosphorescent component may be particularly referred to as a phosphorescent spectrum.

[0054] (Embodiment 1) An organic semiconductor device has at least a pair of electrodes (a first electrode and a second electrode) and an organic compound layer, and the organic compound layer has an active layer or active region. The organic compound layer preferably has a laminated structure made up of functional layers each containing an organic compound that is functionally separated and has properties according to its role, as shown in Figure 1.

[0055] These functional layers are required to have a variety of functions, and representative examples of such functional layers include a carrier injection layer, a carrier transport layer, an active layer (such as a light-emitting layer or a photoelectric conversion layer), a charge generation layer, a carrier blocking layer, and an exciton blocking layer. Each functional layer may also have other functions. For example, since the electron blocking layer is intended to transport holes and the hole blocking layer is intended to transport electrons, they can also be referred to as carrier transport layers (hole transport layers or electron transport layers).

[0056] As described above, each functional layer is composed of an organic compound having properties corresponding to the function required for that layer. Therefore, the development of organic compounds having properties suitable for each functional layer has been actively pursued, and many organic compounds have been proposed and put to practical use.

[0057] Furthermore, the characteristics of organic semiconductor devices vary greatly depending on how these organic compounds are combined, and research into such organic semiconductor device structures is also being actively conducted.

[0058] An organic semiconductor device (also referred to as a light-emitting device) in which the active layer is a light-emitting layer contains a light-emitting center substance in the light-emitting layer. Representative examples of the light-emitting center substance contained in the light-emitting layer of a light-emitting device include a fluorescent substance, a phosphorescent substance, and a thermally activated delayed fluorescence (TADF) substance.

[0059] Light-emitting devices using fluorescent materials as the luminescent center materials have good color purity and good reliability, and therefore fluorescent materials are often used as the luminescent center materials in light-emitting devices.

[0060] In a light-emitting device according to one embodiment of the present invention, a fluorescent material is used in an light-emitting layer, the light-emitting layer contains a host material composed of a plurality of organic compounds including a polycyclic hydrocarbon, and a hole-transport layer (which also functions as an electron-blocking layer) formed in contact with the electrode side of the light-emitting layer that functions as an anode contains an organic compound having a specific structure. This configuration enables the light-emitting device according to one embodiment of the present invention to have significantly improved reliability.

[0061] That is, a light-emitting device of one embodiment of the present invention includes, in a light-emitting layer, a fluorescent substance, a first organic compound including a first polycyclic hydrocarbon, and a second organic compound including a second polycyclic hydrocarbon, and includes, in a hole-transport layer in contact with the light-emitting layer, a third organic compound having an amine skeleton and a polycyclic heteroaromatic ring.

[0062] In this structure, the first polycyclic hydrocarbon contained in the first organic compound is preferably an aromatic hydrocarbon having 6 to 22 carbon atoms in order to efficiently inject carriers into the light-emitting layer. Furthermore, the first polycyclic hydrocarbon preferably has a substituted or unsubstituted aryl group having 6 to 22 carbon atoms in order to provide a light-emitting device with high luminous efficiency and long operating life. Furthermore, the first polycyclic hydrocarbon preferably has an anthracene skeleton in order to efficiently emit light from the fluorescent material, improve the carrier balance in the light-emitting layer, and provide a light-emitting device with high luminous efficiency and enable the device to be driven at a low voltage. When the first polycyclic hydrocarbon has an anthracene skeleton, it is preferable that the anthracene skeleton has substituents at the 9th and 10th positions in order to provide a light-emitting device with high reliability.

[0063] In this configuration, the second polycyclic hydrocarbon contained in the second organic compound is preferably an aromatic hydrocarbon having 6 to 22 carbon atoms in order to efficiently inject carriers into the light-emitting layer. Furthermore, the second polycyclic hydrocarbon is preferably a substituted or unsubstituted aryl group having 6 to 22 carbon atoms in order to provide a light-emitting device with high luminous efficiency and long operating life. Furthermore, the second polycyclic hydrocarbon preferably has an anthracene skeleton in order to efficiently emit light from the fluorescent material, improve the carrier balance in the light-emitting layer, and obtain a light-emitting device with high luminous efficiency, and also enable the device to be driven at a low voltage. When the second polycyclic hydrocarbon has an anthracene skeleton, the anthracene skeleton preferably has substituents at the 9th and 10th positions.

[0064] It is preferable that both the first polycyclic hydrocarbon in the first organic compound and the second polycyclic hydrocarbon in the second organic compound contain an anthracene skeleton, and preferably both contain an anthracene skeleton, because this improves the carrier balance of the light-emitting layer, allows for a light-emitting device with high luminous efficiency, and enables the device to be driven at a low voltage. However, the first organic compound and the second organic compound are different organic compounds. Furthermore, since the anthracene skeleton has a low lowest triplet excitation level (T1 level), when used as a host material for the light-emitting layer, it is preferable that upconversion to singlet excitons can be efficiently induced using triplet-triplet annihilation (TTA), thereby enabling a device with high luminous efficiency. Furthermore, it is preferable that both the first organic compound and the second organic compound contain an anthracene skeleton, because this improves the carrier balance of the light-emitting layer and also improves the heat resistance of the light-emitting layer, thereby improving the heat resistance of the entire device.

[0065] The first organic compound and the second organic compound have, in addition to the first polycyclic hydrocarbon and the second polycyclic hydrocarbon, one or both of an aromatic hydrocarbon and a polycyclic heteroaromatic ring.

[0066] It is preferable that both the first organic compound and the second organic compound are aromatic hydrocarbons in order to obtain a light-emitting device with high luminous efficiency and long operating life.Furthermore, it is preferable that one of the first organic compound and the second organic compound is an aromatic hydrocarbon and the other is an organic compound having a polycyclic heteroaromatic ring, in order to suppress changes in luminous efficiency due to changes in luminance, thereby providing a light-emitting device that can provide a display device with good display quality.

[0067] As described above, the first polycyclic hydrocarbon in the first organic compound and the second polycyclic hydrocarbon in the second organic compound preferably contain an anthracene skeleton. That is, in the light-emitting device of one embodiment of the present invention, the first organic compound and the second organic compound are preferably each independently an organic compound represented by the following general formula (G0). However, the first organic compound and the second organic compound are different organic compounds.

[0068]

[0069] However, in general formula (G0), R １０１ ~R １１０ are each independently any one of hydrogen (including deuterium), a substituted or unsubstituted branched or linear alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 22 carbon atoms, and a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms, and hydrogen (including deuterium), a phenyl group, a naphthyl group, a phenylnaphthyl group, a dibenzofuranyl group, a naphthobenzofuranyl group, etc. are preferred. Note that the organic compound represented by the above general formula (G0) can be １０９ and R １１０ It is preferred that the group has a substituent.

[0070] Furthermore, it is preferable that both the first organic compound and the second organic compound are aromatic hydrocarbons in order to obtain a light-emitting device with high emission efficiency and long operating lifetime. That is, in the light-emitting device of one embodiment of the present invention, the first organic compound and the second organic compound are each independently an organic compound represented by the following general formula (G1). However, the first organic compound and the second organic compound are different organic compounds.

[0071]

[0072] However, in general formula (G1), R １ ~R １０are each independently any one of hydrogen (including deuterium), a substituted or unsubstituted branched or linear alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 22 carbon atoms, and hydrogen (including deuterium), a phenyl group, a naphthyl group, a phenylnaphthyl group, etc. are preferred. Note that the organic compound represented by the general formula (G1) can be formed by adding R ９ and R １０ It is preferred that the group has a substituent.

[0073] Furthermore, it is preferable that the first organic compound be an aromatic hydrocarbon and the second organic compound be an organic compound having a polycyclic heteroaromatic ring, because this makes it possible to suppress a change in luminance-related luminance efficiency and provide a display device with good display quality. That is, it is preferable that the first organic compound be an organic compound represented by the following general formula (G1), and the second organic compound be an organic compound represented by the following general formula (G2):

[0074]

[0075] However, in general formula (G1), R １ ~R １０ are each independently any one of hydrogen (including deuterium), a substituted or unsubstituted branched or linear alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 22 carbon atoms, and hydrogen (including deuterium), a phenyl group, a naphthyl group, a phenylnaphthyl group, etc. are preferred. Note that the organic compound represented by the general formula (G1) can be formed by adding R ９ and R １０ It is preferred that the group has a substituent.

[0076]

[0077] However, in general formula (G2), R １１ ~R ２０each independently represents hydrogen (including deuterium), a substituted or unsubstituted branched or linear alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 22 carbon atoms, or a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms; R １１ ~R ２０ At least one of the groups represents a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms. The aryl group having 6 to 22 carbon atoms is preferably a phenyl group, a naphthyl group, or a phenylnaphthyl group, and the heteroaryl group having 1 to 30 carbon atoms is preferably a dibenzofuranyl group, a naphthobenzofuranyl group, or the like. The organic compound represented by the general formula (G2) can be formed by adding R １９ and R ２０ It is preferred that the group has a substituent.

[0078] It is preferable that one or both of the first organic compound and the second organic compound be deuterated, since this allows for the provision of a light-emitting device with a long operating life. All hydrogen atoms in the organic compound may be deuterium, or only a portion of the hydrogen atoms may be deuterium. Furthermore, when only a portion of the hydrogen atoms are deuterated, it is more preferable that the first polycyclic hydrocarbon, the second polycyclic hydrocarbon, and the polycyclic heteroaromatic ring are deuterated, since this enhances the effect of extending the operating life. It is preferable that one or both of the first organic compound and the second organic compound are deuterated, since the proportion of deuterium atoms in the hydrogen atoms (including deuterium atoms) in the organic compound is 10% or more, preferably 30% or more, and more preferably 50% or more.

[0079] The third organic compound is preferably an organic compound represented by the following general formula (G3).

[0080]

[0081] In general formula (G3), Ar １ , Ar ３ and Ar ５ represents a substituted or unsubstituted arylene group having 6 to 22 carbon atoms or a substituted or unsubstituted heteroarylene group having 1 to 30 carbon atoms; Ar ２and Ar ４ represents any one of a substituted or unsubstituted aryl group having 6 to 22 carbon atoms and a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms; n, m, and l represent an integer of 0 to 3; when n, m, and l are 2 or more, a plurality of Ar １ or Ar ３ or Ar ５ may be the same or different, and Ar ６ is represented by any one of the following general formulas (g3-1) to (g3-4).

[0082]

[0083] In the general formulae (g3-1) to (g3-4), X represents an oxygen atom, a sulfur atom, or nitrogen. When X is a nitrogen atom, the nitrogen atom is ５ or a bond to nitrogen, a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, a linear or branched alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms. ２１ ~R ２８ , and R ３０ ~R ３５ and R ４０ ~R ４５ and R ５０ ~R ５５ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted branched or linear alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 22 carbon atoms, and a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms; R ２１ ~R ２８ One of the following, or R ３０ ~R ３５ One of the following, or R ４０ ~R ４５ One of the following, or R ５０ ~R ５５ One of them is Ar in general formula (G3). ５ Or it represents a bond to nitrogen.

[0084] In the general formulas (g3-1) to (g3-4), X is preferably a sulfur atom or an oxygen atom because the highest occupied molecular orbital (HOMO) level is lower than when it is a nitrogen atom. When a material having an anthracene skeleton is used for the light-emitting layer, the HOMO level of the host material for the light-emitting layer tends to be lower than −5.6 eV, so a low HOMO level of the third organic compound is preferred because it facilitates hole injection into the light-emitting layer. An oxygen atom is preferred because it prevents the molecular weight from becoming too large and the deposition temperature from becoming too high.

[0085] The third organic compound is preferably an organic compound whose lowest unoccupied molecular orbital (LUMO) level is higher than the LUMO level of the materials constituting the light-emitting layer (at least the first organic compound and the second organic compound, and preferably also the fluorescent material), preferably by 0.30 eV or more. This is preferable because it can more effectively prevent electrons from penetrating from the light-emitting layer to the first electrode (anode) side, and it is possible to prevent carrier escape from the light-emitting layer, thereby providing a light-emitting device with high light-emitting efficiency. Furthermore, it is possible to suppress injection of electrons into the third organic compound, thereby preventing deterioration of the third organic compound due to electrons, and resulting in a light-emitting device with better reliability.

[0086] In the above general formulae (G0) to (G3), examples of the branched or linear alkyl group having 1 to 8 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, a neopentyl group, a hexyl group, an isohexyl group, a heptyl group, an octyl group, a 3-methylpentyl group, a 2-methylpentyl group, a 2-ethylbutyl group, a 1,2-dimethylbutyl group, a 2,3-dimethylbutyl group, a 2-ethylhexyl group, a 1-ethylpropyl group, a heptyl group, an octyl group, a 3-methylpentyl group, a 2-methylpentyl group, a 2-ethylbutyl group, a 1,2-dimethylbutyl group, and a 2,3-dimethylbutyl group. When the alkyl group having 1 to 8 carbon atoms has a substituent, examples of the substituent include a cycloalkyl group having 3 to 6 carbon atoms, an aryl group having 6 to 13 carbon atoms, and the like.

[0087] In the above general formulae (G0) to (G3), examples of the substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a 1-methylcyclohexyl group, a cycloheptyl group, a 1-adamantyl group, and a 2-adamantyl group. When the cycloalkyl group having 3 to 10 carbon atoms has a substituent, examples of the substituent include an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms.

[0088] In the above general formulas (G0) to (G3), examples of the substituted or unsubstituted aryl group having 6 to 22 carbon atoms include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a mesityl group, a biphenyl-2-yl group (o-biphenyl group), a biphenyl-3-yl group (m-biphenyl group), a biphenyl-4-yl group (p-biphenyl group), a 1-naphthyl group, a 2-naphthyl group, a phenylnaphthyl group, a naphthylphenyl group, a terphenyl group, a fluorenyl group, a 9,9-dimethylfluorenyl group, a quaterphenyl group, a spirobifluorenyl group, a phenanthrenyl group, an anthracenyl group, a binaphthylphenyl group, a fluoranthenyl group, etc. When the aryl group having 6 to 22 carbon atoms has a substituent, the substituent can be an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, or an aryl group having 6 to 13 carbon atoms.

[0089] In the above General Formulae (G0) to (G2), examples of the substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms include a pyridinyl group, a pyrimidinyl group, a triazinyl group, a phenanthroline-yl group, a carbazolyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a bipyridinyl group, a bipyrimidinyl group, a pyrazinyl group, a bipyrazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a benzoquinoxalinyl group, a dibenzoquinoxalinyl group, an azofluorenyl group, a diazofluorenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzofuranyl group, a benzofuranyl group, and a benzonaphthofuranyl group. , a dinaphthofuran-yl group, a dibenzothiophen-yl group, a benzothiophen-yl group, a benzonaphthothiophen-yl group, a dinaphthothiophen-yl group, a benzofuropyridin-yl group, a benzofuropyrimidin-yl group, a benzothiopyridin-yl group, a benzothiopyrimidin-yl group, a naphthofuropyridin-yl group, a naphthofuropyrimidin-yl group, a naphthothiopyridin-yl group, a naphthothiopyrimidin-yl group, a dibenzoquinoxalin-yl group, an acridine-yl group, a xanthene-yl group, a phenothiazin-yl group, a phenoxazin-yl group, a phenazin-yl group, a triazol-yl group, an oxazol-yl group, an oxadiazol-yl group, a thiazol-yl group, a thiadiazol-yl group, a benzimidazol-yl group, or a pyrazol-yl group. When the heteroaryl group having 1 to 30 carbon atoms has a substituent, examples of the substituent include an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms.

[0090] In General Formula (G3), examples of the substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms include a carbazole group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazole group, a benzocarbazole group, a dibenzocarbazole group, a dibenzofuranyl group, a benzofuranyl group, a benzonaphthofuranyl group, a dinaphthofuranyl group, a dibenzothiophenyl group, a benzothiophenyl group, a benzonaphthothiophenyl group, a dinaphthothiophenyl group, an acridine group, a xanthene group, a phenothiazinyl group, a phenoxazinyl group, and a benzimidazole group. When the heteroaryl group having 1 to 30 carbon atoms has a substituent, examples of the substituent include an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 13 carbon atoms.

[0091] Examples of the organic compound represented by the general formula (G1) include organic compounds represented by the following structural formulas (100) to (117).

[0092]

[0093]

[0094] Examples of the organic compound represented by the general formula (G2) include organic compounds represented by the following structural formulas (200) to (215).

[0095]

[0096]

[0097] The organic compound represented by the general formula (G0) corresponds to both the specific example of the organic compound represented by the general formula (G1) and the specific example of the organic compound represented by the general formula (G2).

[0098] Examples of the organic compound represented by the general formula (G3) include organic compounds represented by the following structural formulas (300) to (339).

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105] A light-emitting device according to one embodiment of the present invention having such a structure can be a highly reliable light-emitting device and can provide a display device with high display quality.

[0106] In the light-emitting device of one embodiment of the present invention, the lowest singlet excitation level (S1 level) of the fluorescent substance used in the light-emitting layer is preferably lower than the S1 level of the first organic compound and the S1 level of the second organic compound, and the T1 level of the fluorescent substance is preferably higher than the T1 level of the first organic compound and / or the T1 level of the second organic compound. This allows efficient upconversion to singlet excitons using TTA.

[0107] The upconversion to singlet excitons using TTA occurs when triplet excitons generated by carrier recombination interact with each other, transferring excitation energy and exchanging spin angular momentum, resulting in conversion to singlet excitons having the energy of the S1 level of the host material. Because the energy of the generated singlet excitons is higher than the energy of the S1 level of the fluorescent material, the triplet excitation energy of the host material can be converted into fluorescent light. This allows the light-emitting device of one embodiment of the present invention to emit light more efficiently.

[0108] The S1 level of an organic compound can be calculated by drawing a tangent at the value where the slope of the short wavelength side of the peak in the fluorescence spectrum is maximum, and the energy of the wavelength at the intersection of the tangent with the horizontal axis (wavelength) or the baseline can be taken as the S1 level. The T1 level of an organic compound can be calculated by drawing a tangent at the value where the slope of the short wavelength side of the peak in the phosphorescence spectrum is maximum, and the energy of the intersection of the tangent with the horizontal axis (wavelength) or the baseline can be taken as the T1 level (see, for example, Daisaku Tanaka et al., "Ultra High Efficiency Green Organic Light-Emitting Devices," Japanese Journal of Applied Physics, Vol. 46, No. 1, 2007, pp. L10-L12). Alternatively, when a ν=0→ν=0 transition (0→0 band) between the vibrational levels of the ground state and the excited state is clearly observed in the fluorescence spectrum or phosphorescence spectrum, the D* level, the S1 level, or the T1 level can also be calculated using the 0→0 band. (Nicholas J. Turro, V. Ramamurthy, J.C. Scaiano, Haruo Inoue, Osamu Ito, Supervising Editor, Translated, "Principles of Molecular Photochemistry", Maruzen Publishing Co., Ltd., July 30, 2013, pp. 165-169; Nicholas J. Turro, V. Ramamurthy, J.C. Scaiano, "MODERN MOLECULAR PHOTOCHEMISTRY OF ORGANIC MOLECULES", University Science Books, published February 10, 2010, pp. 204-208). In this specification, each level is calculated by the former method of drawing a tangent line. Furthermore, when comparing levels, the comparison should be made at levels calculated using the same method.

[0109] Here, each spectrum may be measured in a thin film state or in a solution state, but for fluorescent substances, a solution is preferred from the viewpoint of verifying the state of isolated molecules. However, when comparing spectra, comparison should be made as much as possible using data obtained in the same sample form, such as measurement results of thin films or solutions.

[0110] When the measurement is carried out in a solution state, the solvent may be hexane, benzene, toluene, diethyl ether, ethyl acetate, chloroform, chlorobenzene, dichloromethane, 2-methyltetrahydrofuran (2-MeTHF), or the like, with toluene, dichloromethane, and 2-MeTHF being preferred.

[0111] When observing phosphorescent components at low temperatures, a mixed solvent of iodobenzene:dichloromethane:toluene=20%:40%:40% may be used because it can form a good glass state.

[0112] When observing a phosphorescence spectrum in a solution, it is preferable to measure at 77 K, which is the temperature of liquid nitrogen. When observing a phosphorescence spectrum in a thin film, it is preferable to measure between about 4 K and 10 K, since the temperature of liquid helium is 4 K. When measuring an emission spectrum at a low temperature, a delayed fluorescence spectrum may appear in addition to the phosphorescence spectrum. In this case, a comparison with the emission spectrum (fluorescence spectrum) at room temperature can be made, and an emission spectrum having a peak at the same wavelength as the fluorescence emission spectrum can be determined to be a delayed fluorescence spectrum.

[0113] This embodiment mode can be used in any combination with other embodiments.

[0114] Embodiment 2 In this embodiment, a light-emitting device that is an organic semiconductor according to one embodiment of the present invention will be described in detail. FIG. 1A illustrates a light-emitting device according to one embodiment of the present invention. The light-emitting device according to one embodiment of the present invention includes an organic compound layer 103 between a first electrode 101 formed over an insulating layer 1000 and a second electrode 102 facing the first electrode. The organic compound layer 103 includes at least a light-emitting layer 113 and may further include other functional layers. 1A and 1B show an example in which the device includes the hole injection layer 111, the hole transport layer 112, and the electron transport layer 114 (and the electron injection layer 115), but the device may also include an exciton blocking layer, a charge generating layer, or the like. Note that, in the hole transport layer 112, a layer that is in contact with the light-emitting layer 113 may be particularly referred to as an electron blocking layer, and in the electron transport layer 114, a layer that is in contact with the light-emitting layer may be particularly referred to as a hole blocking layer. In this embodiment, a case in which the first electrode 101 functions as an anode and the second electrode 102 functions as a cathode will be described as an example, but the reverse may also be true.

[0115] Note that the light-emitting layer and the hole-transport layer have the structures described in Embodiment 1. Thus, the light-emitting device of one embodiment of the present invention can be a highly reliable light-emitting device.

[0116] The anode is preferably formed using a metal, alloy, conductive compound, or mixture thereof having a large work function (specifically, 4.0 eV or more). Specific examples include indium oxide-tin oxide (ITO), indium oxide-tin oxide containing silicon or silicon oxide (ITSO), indium oxide-zinc oxide, and indium oxide containing tungsten oxide and zinc oxide (IWZO). These conductive metal oxide films are usually formed by sputtering, but may also be formed by applying a sol-gel method. As an example of a fabrication method, indium oxide-zinc oxide can be formed by sputtering using a target in which 1 to 20 wt % of zinc oxide is added to indium oxide. Indium oxide containing tungsten oxide and zinc oxide (IWZO) can also be formed by sputtering using a target containing 0.5 to 5 wt % tungsten oxide and 0.1 to 1 wt % zinc oxide relative to indium oxide. Other materials that can be 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), titanium (Ti), aluminum (Al), or nitrides of metal materials (e.g., titanium nitride). A layer formed by stacking these materials can also be used as the anode. For example, a film formed by stacking Al, Ti, and ITSO on Ti in this order is preferred because it has good reflectivity, is highly efficient, and enables high resolution of several thousand ppi. Graphene can also be used as the anode material. In addition, by using a composite material capable of forming the hole injection layer 111 described later as a layer in contact with the anode (typically, a hole injection layer), it becomes possible to select an electrode material regardless of the work function.

[0117] The hole injection layer 111 is provided in contact with the anode and has a function of facilitating injection of holes into the organic compound layer 103. The hole injection layer 111 is made of phthalocyanine (abbreviation: H ２The organic EL element can be formed from a phthalocyanine compound or complex compound such as copper phthalocyanine (abbreviated as CuPc), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as DPAB) or 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviated as DNTPD), or a polymer such as poly(3,4-ethylenedioxythiophene) / polystyrene sulfonic acid (abbreviated as PEDOT / PSS).

[0118] The hole-injection layer 111 may be formed using a substance having electron acceptor properties. Examples of the substance having acceptor properties include organic compounds having an electron-withdrawing group (such as a halogen group or a cyano group), such as 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-TCCNNQ), and 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile. In particular, compounds in which an electron-withdrawing group is bonded to a fused aromatic ring having a plurality of heteroatoms, such as HAT-CN, are thermally stable and preferred. Also, [3]radialene derivatives having an electron-withdrawing group (especially a halogen group such as a fluoro group, a cyano group, etc.) are preferred because they have very high electron-accepting properties, and specific examples thereof include α,α',α''-1,2,3-cyclopropanetriylidenetris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidenetris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], and α,α',α''-1,2,3-cyclopropanetriylidenetris[2,3,4,5,6-pentafluorobenzeneacetonitrile]. As the substance having 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. ２The hole injection layer 111 can also be formed from a phthalocyanine compound or complex compound such as copper phthalocyanine (abbreviated as CuPc), aromatic amine compounds such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as DPAB) or 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviated as DNTPD), or a polymer such as poly(3,4-ethylenedioxythiophene) / polystyrene sulfonic acid (abbreviated as PEDOT / PSS). A substance having acceptor properties can extract electrons from an adjacent hole transport layer (or hole transport material) when an electric field is applied.

[0119] The hole-injection layer 111 is preferably formed using a composite material containing the above-described material having an acceptor property and a substance having a hole-transport property.

[0120] As a substance having a hole transport 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. −６ cm ２ / Vs or more. The substance having hole transport properties used in the composite material is preferably a compound having a fused aromatic hydrocarbon ring or a π-electron-rich heteroaromatic ring. As the fused aromatic hydrocarbon ring, an anthracene ring, a naphthalene ring, or the like is preferable. As the π-electron-rich heteroaromatic ring, a fused aromatic ring containing at least one of a pyrrole skeleton, a furan skeleton, and a thiophene skeleton 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 fused to the above ring is preferable.

[0121] Such a substance having hole-transporting properties preferably has a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, or an anthracene skeleton. In particular, the substance 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. It is preferable that the substance having hole-transporting properties is a substance having an N,N-bis(4-biphenyl)amino group, since this allows the manufacture of a light-emitting device with a long lifetime.

[0122] Specific examples of the substance having the hole transport property as described above include 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-8-yl, and N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-yl. [b]naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]- N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (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: BBAαNβN B-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'-(3-phenyl-9H-carbazol-9-yl)biphenyl-4''-[ ... N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9′-spirobi[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N- Bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-[4-(9-phenylfluoren- 4,4'-diphenyl-4'-(9-phenyl-9H-carbazol-3-yl)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 N-(biphenyl-3-yl)triphenylamine (abbreviation: PCBNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF), N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-4- amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-1-amine, 9-[3-(triphenylsilyl)phenyl]-3,9'-bi-9H-carbazole (abbreviation: PSiCzCz), 9'-phenyl-9'H-9,3':6',9"-tercarbazole (abbreviation: PSiCzGI), etc.

[0123] Other aromatic amine compounds that can be used as the substance having hole-transporting properties include 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), and 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B).

[0124] By forming the hole injection layer 111, the hole injection property becomes good, and a light emitting device with a low driving voltage can be obtained.

[0125] Among substances having acceptor properties, organic compounds having acceptor properties are easy to use because they can be easily vapor-deposited and formed into a film.

[0126] The hole transport layer 112 is formed by including a substance having a hole transport property. −６ cm ２ It is preferable that the material has a hole mobility of 1.0 V or more.

[0127] The hole-transporting layer 112 may have either a single-layer structure or a stacked-layer structure, but the layer in contact with the light-emitting layer 113 has the structure described in Embodiment 1. Note that repeated description of this structure will be omitted.

[0128] When the hole-transport layer 112 has a stacked structure, layers other than the layer in contact with the light-emitting layer 113 do not necessarily have the structure described in Embodiment 1. In the hole-transport layer having a stacked structure, layers other than the layer in contact with the light-emitting layer 113 are formed containing a substance having a hole-transport property. −６ cm ２ It is preferable that the material has a hole mobility of 1.0 V or more.

[0129] Examples of the substance having a hole-transporting property include 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N′-diphenyl-N,N′-bis(3-methylphenyl)-4,4′-diaminobiphenyl (abbreviation: TPD), N,N′-bis(9,9′-spirobi[9H-fluoren]-2-yl)-N,N′-diphenyl-4,4′-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), and 4-phenyl-3-methylphenyl-4,4′-diaminobiphenyl (abbreviation: 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB). 4,4'-diphenyl-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: PCBA1BP), compounds having an aromatic amine skeleton such as 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-3,3'-bi-9H-carbazole (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'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, 9-phenyl-9'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviation: PCCzTp), 9,9'-bis(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(4-biphenyl)-9'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, compounds having a carbazole skeleton such as N,N-bis(9,9-dimethyl-9H-fluoren-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-fluoren-1-amine, and 9-[3-(triphenylsilyl)phenyl]-3,9'-bi-9H-carbazole (abbreviation: PSiCzCz); 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II);Examples of suitable compounds include compounds having a thiophene skeleton, such as 8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III) and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), and compounds having a furan skeleton, such as 4,4′,4″-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II). Among the compounds listed above, compounds having an aromatic amine skeleton and compounds having a carbazole skeleton are preferred because they have good reliability, high hole transport properties, and contribute to reducing driving voltage. The organic compounds listed as the substances having hole-transport properties used in the composite material of the hole-injection layer 111 can also be suitably used as materials for the hole-transport layer 112. It is more preferable to use an organic compound having an amine skeleton and a fluorene skeleton. Furthermore, organic compounds having an amine skeleton and a fluorene skeleton are preferable because they have good reliability and high hole-transport properties, thereby reducing the power consumption of the light-emitting device.

[0130] The luminescent center substance contained in the light-emitting layer 113 is a fluorescent substance. Examples of the fluorescent substance include the following: In addition, fluorescent substances other than these may also be used.

[0131] 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 )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-carbazol-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), N,N''-(2-tert-butylanthracene-9,10-diyldi-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-carbazol-3-amine (abbreviation: 2PAPPA), 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, N-(9,10-diphenyl-2-anthryl)-N,9-Diphenyl-9H-carbazole-3-amine (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-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracen-9-amine (abbreviation: DPhAPhA), Coumarin 545T, N,N'-diphenylquinacridone (abbreviation: DPQd), rubrene, 5,12-bis(biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyra N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhTD), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: 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-mPhTD), Name: 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: BisDCJ™), N,N'-diphenyl-N,N'-(1,6-pyren-diyl)bis[(6-phenylbenzo[b]naphthyl)benzo[b]naphthyl] ... 6,7-b']bisbenzofuran-3,10-diamine (abbreviation: 3,10PCA2Nbf(IV)-02), and 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02). In particular, condensed aromatic diamine compounds, such as pyrenediamine compounds 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03, are preferred because they have high hole trapping properties and excellent luminous efficiency or reliability.

[0132] Furthermore, 5,9-diphenyl-5,9-diaza-13b-boranaphtho[3,2,1-de]anthracene (abbreviation: DABNA1), 9-(biphenyl-3-yl)-N,N,5,11-tetraphenyl-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborin-3-amine (abbreviation: DABNA2), 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl)-N,N-diphenyl-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborin-7-amine (abbreviation: DABNA3), amine (abbreviation: DPhA-tBu4DABNA), 2,12-di(tert-butyl)-N,N,5,9-tetra(4-tert-butylphenyl)-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborin-7-amine (abbreviation: tBuDPhA-tBu4DABNA), 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl)-7-methyl-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborin (abbreviation: Me-tBu4DABNA), N ７ , N ７ , N １３ , N １３ Condensed heteroaromatic compounds containing nitrogen and boron, such as 5,9,11,15-octaphenyl-5H,9H,11H,15H-[1,4]benzazaborino[2,3,4-kl][1,4]benzazaborino[4',3',2':4,5][1,4]benzazaborino[3,2-b]phenazaborine-7,13-diamine (abbreviation: v-DABNA), and 2-(4-tert-butylphenyl)benz[5,6]indolo[3,2,1-jk]benzo[b]carbazole (abbreviation: tBuPBibc), in particular compounds having a diazaboranaphthoanthracene skeleton, can be suitably used because they have a narrow emission spectrum and can emit blue light with good color purity.

[0133] In addition to these, 9,10,11-tris[3,6-bis(1,1-dimethylethyl)-9H-carbazolyl-9-yl]-2,5,15,18-tetrakis(1,1-dimethylethyl)indolo[3,2,1-de]indolo[3',2',1':8,1][1,4]benzazaborino[2,3,4-kl]phenazaborine (abbreviation: BBCz-G), 9,11-bis[3,6-bis(1,1-dimethylethyl)-9H-carbazolyl-9-yl]-2,5,15,18-tetrakis(1,1-dimethylethyl)indolo[3,2,1-de]indolo[3',2',1':8,1][1,4]benzazaborino[2,3,4-kl]phenazaborine (abbreviation: BBCz-Y) and the like can be preferably used.

[0134] The first host material and the second host material contained together with the fluorescent material in the light-emitting layer 113 have been described in detail in Embodiment 1, and therefore, repeated description will be omitted. Please refer to Embodiment 1.

[0135] In a light-emitting device according to one embodiment of the present invention, at least one of the light-emitting layer and the hole-transport layer has the structure disclosed in Embodiment 1. When a light-emitting device has a plurality of light-emitting layers, the other light-emitting layers do not need to have a fluorescent material as the luminescence center substance. In a light-emitting device according to one embodiment of the present invention, at least one light-emitting device has the structure disclosed in Embodiment 1. The other light-emitting devices included in the light-emitting device do not need to have a fluorescent material as the luminescence center substance. In this case, the light-emitting layer of the light-emitting device may have the following structure.

[0136] When a phosphorescent material is used as the light-emitting material in the light-emitting layer, the phosphorescent material is preferably a metal complex, particularly an iridium complex or a platinum complex, and examples thereof include the following materials.

[0137] Tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN]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 ]), organometallic iridium complexes having a 4H-triazole skeleton such as 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 organometallic iridium complexes having a 1H-triazole skeleton, such as 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 organometallic iridium complexes having an imidazole skeleton, such as tris(2-{1-[2,6-bis(1-methylethyl)phenyl]-1H-imidazol-2-yl-κN}-4-cyanophenyl-κC)iridium(III) (abbreviation: CNImIr), tris[(6-tert-butyl-3-phenyl-2H-imidazo[4,5-b]pyrazin-1-yl-κC)phenyl-κC]iridium(III) (abbreviation: [Ir(cb) ３ organometallic complexes having a benzimidazolidene skeleton, such as 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(CF ３ ppy) ２(pic)]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C ２’ Examples of suitable iridium complexes include organometallic iridium complexes having a phenylpyridine derivative having an electron-withdrawing group as a ligand, such as iridium(III) acetylacetonate (abbreviation: FIracac), and platinum complexes such as (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-(4-tert-butyl-2-pyridinyl-κN)carbazole-2,1-diyl-κC1)platinum(II) (abbreviation: PtON-TBBI). These compounds exhibit blue phosphorescence and have an emission peak in the wavelength range of 450 nm to 520 nm. Compounds in which some of the hydrogen atoms in these compounds are replaced with deuterium atoms can also be used.

[0138] Also, 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) ２organometallic iridium complexes having a pyrimidine 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 organometallic iridium complexes having a pyrazine skeleton, such as tris(2-phenylpyridinato-N,C(acac)]); 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-d ３ [5-methyl-2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(5mppy-d ３ ) ２ (mbfpypy-d ３ )), {2-(methyl-d ３ )-8-[4-(1-methylethyl-1-d)-2-pyridinyl-κN]benzofuro[2,3-b]pyridin-7-yl-κC}bis{5-(methyl-d ３ )-2-[5-(methyl-d ３)-2-pyridinyl-κN]phenyl-κC}iridium(III) (abbreviation: Ir(5mtpy-d6) ２ (mbfpypy-iPr-d ４ )), [2-d ３ -methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy) ２ (mbfpypy-d ３ )), [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-d ３ -methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(5-d ３ [Ir(5mppy-d-methyl-2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(5mppy-d-methyl-2-pyridinyl-κN)phenyl-κC]iridium(III) ３ )2(mdppy-d ３ ) )]), [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-d ３ ) ３In addition to organometallic iridium complexes having a pyridine skeleton such as (2-{1-(5-tert-butylbiphenyl-2-yl)-4-[3-tert-butyl-5-(4-phenyl-2-pyridinyl-κN)phenyl-κC6]-2-benzimidazolyl-κN3}-4,6-di-tert-butylphenolato-κO)platinum(II) (abbreviation: Pt(tBudppymmtBubiz-tBubp)), {2-[4-(3,5-di-te organometallic platinum complexes such as tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: [Tb(acac)]), ... ３ Examples of suitable compounds include rare earth metal complexes such as iridium complexes containing iridium ions (Phen). These compounds are primarily compounds that exhibit green phosphorescence and have an emission peak in the wavelength range of 500 nm to 600 nm. Organometallic iridium complexes having a pyrimidine skeleton are particularly preferred because they are remarkably excellent in reliability and luminous efficiency. Compounds in which some of the hydrogen atoms in these compounds are replaced with deuterium atoms can also be used.

[0139] Also, (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(dpm) ２ organometallic iridium complexes having a pyrimidine skeleton, such as (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 organometallic iridium complexes having a pyrazine skeleton, such as tris(1-phenylisoquinolinato-N,C(acac)]); ２’ ) Iridium(III) (abbreviation: [Ir(piq) ３ ]), bis(1-phenylisoquinolinato-N,C ２’ ) iridium(III) acetylacetonate (abbreviation: [Ir(piq) ２ (acac)]), (3,7-diethyl-4,6-nonanedionato-κO4,κO6)bis[2,4-dimethyl-6-[7-(1-methylethyl)-1-isoquinolinyl-κN]phenyl-κC]iridium(III), (3,7-diethyl-4,6-nonanedionato-κO4,κO6)bis[2,4-dimethyl-6-[5-(1-methylethyl)-2-quinolinyl-κN]phenyl-κC]iridium(III). In addition to organometallic iridium complexes having a pyridine skeleton such as [ru-κC]iridium(III), platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrinplatinum(II) (abbreviation: PtOEP), tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: [Eu(DBM) ３ (Phen)]), tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: [Eu(TTA) ３ Examples of suitable compounds include rare earth metal complexes such as iridium fluoride (Phen). These compounds exhibit red phosphorescence and have an emission peak in the wavelength range of 600 nm to 700 nm. Organometallic iridium complexes having a pyrazine skeleton can emit red light with good chromaticity. Compounds in which some of the hydrogen atoms in these compounds are replaced with deuterium atoms can also be used.

[0140] Note that, by using a deuterated compound as the luminescent center substance, the luminescent efficiency is improved, and therefore, the luminescent center substance is preferably a deuterated material.

[0141] In addition to the phosphorescent compounds described above, known phosphorescent compounds may be selected and used.

[0142] When a substance exhibiting thermally activated delayed fluorescence (thermally activated delayed fluorescence (TADF) material) is used as the luminescent center substance, fullerene and its derivatives, acridine and its derivatives, eosin derivatives, etc. can be used. Further, metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), palladium (Pd), etc. can be used. Examples of the metal-containing porphyrins include protoporphyrin-tin fluoride complexes (SnF) represented by the following structural formula: ２ (Proto IX)), mesoporphyrin-tin fluoride complex (SnF ２ (Meso IX)), hematoporphyrin-tin fluoride complex (SnF ２ (Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (SnF ２ (Copro III-4Me)), octaethylporphyrin-tin fluoride complex (SnF ２ (OEP)), etioporphyrin-tin fluoride complex (SnF ２ (Etio I)), octaethylporphyrin-platinum chloride complex (PtCl ２ OEP) and the like.

[0143]

[0144] Further, 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: PCCzPTzn), and Heterocyclic compounds having one or both of a π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring, such as 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), and 10-phenyl-10H,10′H-spiro[acridine-9,9′-anthracene]-10′-one (abbreviation: ACRSA), can also be used. The heterocyclic compound has a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring, and therefore has high electron transport and hole transport properties, and is therefore preferred. Among the skeletons having a π-electron-deficient heteroaromatic ring, pyridine skeleton, diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), and triazine skeleton are preferred because they are stable and reliable. In particular, benzofuropyrimidine skeleton, benzothienopyrimidine skeleton, benzofuropyrazine skeleton, and benzothienopyrazine skeleton are preferred because they have high acceptor properties and good reliability. Furthermore, among the skeletons having a π-electron-rich heteroaromatic ring, acridine skeleton, phenoxazine skeleton, phenothiazine skeleton, furan skeleton, thiophene skeleton, and pyrrole skeleton are preferred because they are stable and reliable.The furan skeleton is preferably a dibenzofuran skeleton, and the thiophene skeleton is preferably a dibenzothiophene skeleton. Furthermore, the pyrrole skeleton is particularly preferably an indole skeleton, a carbazole skeleton, an indolocarbazole skeleton, a bicarbazole skeleton, or a 3-(9-phenyl-9H-carbazole-3-yl)-9H-carbazole skeleton. Furthermore, in a substance in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded, the electron-donating property of the π-electron-rich heteroaromatic ring and the electron-accepting property of the π-electron-deficient heteroaromatic ring are both enhanced, resulting in S. １ Level and T １ This is particularly preferred because the energy difference between the levels is small, allowing thermally activated delayed fluorescence to be obtained efficiently. Instead of the π-electron-deficient heteroaromatic ring, an aromatic ring bonded to an electron-withdrawing group such as a cyano group may be used. Furthermore, an aromatic amine skeleton, a phenazine skeleton, or the like can be used as the π-electron-rich skeleton. Furthermore, as the π-electron-deficient 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 or boranthrene, 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, or the like can be used. In this way, a π-electron-deficient skeleton and a π-electron-rich skeleton can be used in place of at least one of the π-electron-deficient heteroaromatic ring and the π-electron-rich heteroaromatic ring. Furthermore, compounds in which some of the hydrogen atoms in these compounds are replaced with deuterium can also be used.

[0145]

[0146] The TADF material is S １ Level and T １This material has a small difference in energy level between triplet and singlet excitations, and has the ability to convert energy from triplet excitation to singlet excitation through reverse intersystem crossing. Therefore, triplet excitation energy can be upconverted to singlet excitation energy (reverse intersystem crossing) with a small amount of thermal energy, allowing for efficient generation of a singlet excited state. In addition, triplet excitation energy can be converted into luminescence.

[0147] In addition, an excited complex (also called an exciplex) that forms an excited state with two kinds of substances is S １ Level and T １ The difference between the triplet excitation energy and the singlet excitation energy is extremely small, and the TADF material functions as a TADF material that can convert triplet excitation energy into singlet excitation energy.

[0148] In addition, T １ The phosphorescence spectrum observed at low temperatures (for example, 77 K to 10 K) can be used as an index of the level. For the TADF material, a tangent line is drawn at the base of the fluorescence spectrum on the short wavelength side, and the energy of the wavelength of the extrapolated line is expressed as S １ The level is set as the tangent line at the base of the phosphorescence spectrum on the short wavelength side, and the energy of the wavelength of the extrapolated line is T １ When the level is reached, the S １ and T １ The difference is preferably 0.3 eV or less, and more preferably 0.2 eV or less.

[0149] In addition, when a TADF material is used as a light-emitting material, the energy donor S １ The level is S of the TADF material. １ It is preferable that the T level is higher than the T level of the energy donor. １ The level is the T １ It is preferable that the level is higher.

[0150] In the light-emitting layer, the light-emitting center substance is preferably used together with a host material. As the host material, various organic compounds having carrier transport properties can be used, such as organic compounds having electron transport properties, organic compounds having hole transport properties, and organic compounds having bipolar properties. As the organic compound having electron transport properties that can be used as the host material of the light-emitting layer, an organic compound having an electron mobility of 1×10 or less at a square root of an electric field strength [V / cm] of 600 can be used. −７ cm ２ / Vs or more, preferably 1×10 −６ cm ２ An organic compound having electron transport properties and an electron mobility of 1 / Vs or more is preferred.

[0151] The organic compound having electron transport properties is preferably an organic compound having a π-electron-deficient heteroaromatic ring. Examples of the organic compound having a π-electron-deficient heteroaromatic ring skeleton include an organic compound having a heteroaromatic ring with an azole skeleton, an organic compound having a heteroaromatic ring with a pyridine skeleton, an organic compound having a heteroaromatic ring with a diazine skeleton, and an organic compound having a heteroaromatic ring with a triazine skeleton.

[0152] Among these, organic compounds containing a heteroaromatic ring having a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), organic compounds containing a heteroaromatic ring having a pyridine skeleton, and organic compounds containing a heteroaromatic ring having a triazine skeleton are preferred because of their high reliability. In particular, organic compounds containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing a heteroaromatic ring having a triazine skeleton have high electron transport properties and contribute to reducing driving voltage. In addition, benzofuropyrimidine skeletons, benzothienopyrimidine skeletons, benzofuropyrazine skeletons, and benzothienopyrazine skeletons are preferred because of their high acceptor properties and high reliability.

[0153] As organic compounds having a π-electron-deficient heteroaromatic ring skeleton that can be used as organic compounds having electron transport properties, for example, the following organic compounds are preferred: 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs), and other organic compounds having an azole skeleton, such as 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35 DCzPPy), 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 organic compounds containing a heteroaromatic ring having a pyridine skeleton, such as 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4'-(9-phenyl-9H-carbazol-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), 2-[4-(3,6-diphenyl 1-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 9-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNf pr), 9-[3'-(dibenzothiophen-4-yl)biphenyl-4-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9pmDBtBPNfpr), 4,6-bis[3-(phenanthrene-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'-[pyrimidinyl 4,6-diphenyl-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]pyrimidine [4-(9-phenyl-9H-carbazol-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: PC-cgDBCzQz), 8-(p-terphenyl-3-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm), 2,2'-(2,2'-bipyridine-6,6'-diyl)bis(4-phenylbenzo[h ]quinazoline) (abbreviation: 6,6'(P-Bqn)2BPy), organic compounds having a diazine skeleton such as 2-(biphenyl-4-yl)-4-phenyl-6-(9,9'-spirobi[9H-fluoren]-2-yl)-1,3,5-triazine (abbreviation: BP-SFTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn-02), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]- 4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-{3-[3-(dibenzothiophen-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTzn), 2,4,6-tris[3′-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmP PPyTz), 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-phenyl-indolo[2,3-a]carbazole (abbreviation: BP-Icz(II)Tzn), 2-[3′-(triphenylen-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mT pBPTzn), 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-(biphenylsilyl)phenyl]-1,3,5-triazine (abbreviation: mSiTrz),

[0033] 3-{3-[9-(4,6-diphenyl-1,3,5-triazin-2-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 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]- ... mPCPDBfTzn), 9,9′-[6-(biphenyl-4-yl)-2-phenyl-1,3,5-triazine-4,3″-diyl]bis(9H-carbazole) (abbreviation: mPCPDBfTzn), 9,9′-[6-(biphenyl-4-yl)-2-phenyl-1,3,5-triazine-4,3″-diyl]bis(9H-carbazole) (abbreviation: mPCPDBfTzn), 9,9′-[6-(biphenyl-4-yl)-2-phenyl-1,3,5-triazine-4,3″-diyl]bis(9H-carbazole) (abbr Examples of suitable organic compounds include organic compounds containing a heteroaromatic ring with a triazine skeleton, such as 9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzothienyl]-2-phenyl-9H-carbazole (abbreviation: PCzDBtTzn), 9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzothienyl]-2-phenyl-9H-carbazole (abbreviation: PCzDBtTzn), and 2,4,6-tris(2-pyridyl)-1,3,5-triazine (abbreviation: 2Py3Tz). Organic compounds containing a heteroaromatic ring with a diazine skeleton, organic compounds containing a heteroaromatic ring with a pyridine skeleton, and organic compounds containing a heteroaromatic ring with a triazine skeleton are preferred due to their high reliability. In particular, organic compounds containing a heteroaromatic ring with a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing a heteroaromatic ring with a triazine skeleton have high electron transport properties and contribute to reduced driving voltage.

[0154] The organic compound having hole transport properties and usable as a host material for the light-emitting layer is preferably an organic compound having an amine skeleton or a π-electron-rich heteroaromatic ring skeleton. The π-electron-rich heteroaromatic ring is preferably a fused aromatic ring containing at least one of an acridine skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a furan skeleton, a thiophene skeleton, and a pyrrole skeleton, and specifically preferably a carbazole ring, a dibenzothiophene ring, or a ring in which an aromatic ring or a heteroaromatic ring is fused to one of these rings.

[0155] Such organic compounds having hole-transporting properties preferably have a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, or an anthracene skeleton. In particular, aromatic amines having a substituent containing a dibenzofuran ring or a dibenzothiophene ring, aromatic monoamines having a naphthalene ring, or aromatic monoamines in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group may be used. It is preferable that these hole-transporting substances are organic compounds having an N,N-bis(4-biphenyl)amino group, since this allows the manufacture of light-emitting devices with a long lifetime.

[0156] As such an organic compound, 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-fluoren]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3 ... 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: PCBA1BP), )triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), compounds having an aromatic amine skeleton such as 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-carbazole-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-3,3'-bi-9H-carbazole (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 9-(2-naphthyl)-9'-[1,1':4',1"-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole (abbreviation: βNCCBP), 9,9'-di-2-naphthyl-3,3'-9H,9'H-bicarbazole (abbreviation: BisβNCz), 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'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, 9-phenyl-9'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviation: PCCzTp), 9,9'-bis(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole Carbazole, 9-(4-biphenyl)-9'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(triphenylen-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-fluoren-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]dibenzothiophene (abbreviation: DBTFLP-III), Examples of suitable compounds include compounds having a thiophene skeleton such as [phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), and compounds having a furan skeleton such as 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II). Among the above, compounds having an aromatic amine skeleton or a carbazole skeleton are preferred because they have good reliability, high hole transport properties, and contribute to reducing driving voltage.

[0157] By mixing an organic compound having an electron-transporting property with an organic compound having a hole-transporting property, the transporting property of the light-emitting layer 113 can be easily adjusted, and the recombination region can also be easily controlled. The weight ratio of the contents of the first substance and the second substance may be such that the substance having a hole-transporting property:the substance having an electron-transporting property=1:19 to 19:1.

[0158] In addition, it is preferable that an organic compound having electron transport properties and an organic compound having hole transport properties are combined to form an exciplex. The exciplex is preferably selected from a combination that forms an exciplex that emits light that overlaps with the lowest-energy absorption band of the light-emitting substance, because this allows for smooth energy transfer and efficient light emission. In addition, the use of this structure is also preferable because it reduces the driving voltage.

[0159] As a combination of materials that efficiently form an exciplex, it is preferable that the HOMO level of the organic compound having hole transport properties is equal to or higher than the HOMO level of the organic compound having electron transport properties. It is also preferable that the LUMO level of the organic compound having hole transport properties is equal to or higher than the LUMO level of the organic compound having electron transport properties. The LUMO level and HOMO level of the material can be derived from the electrochemical properties (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV).

[0160] The formation of exciplexes can be confirmed, for example, by comparing the emission spectra of the second organic compound, the first organic compound, and a mixed film obtained by mixing these materials and observing the phenomenon that the emission spectrum of the mixed film is shifted to longer wavelengths than the emission spectra of each material (or has a new peak at longer wavelengths). Alternatively, the formation of exciplexes can be confirmed by comparing the transient photoluminescence (PL) of the second organic compound, the transient PL of the first organic compound, and a mixed film obtained by mixing these materials and observing differences in transient response, such as the transient PL lifetime of the mixed film having a longer-lifetime component or a larger proportion of delayed components than the transient PL lifetimes of each material. The above-mentioned transient PL may also be interpreted as transient electroluminescence (EL). In other words, the formation of exciplexes can also be confirmed by comparing the transient EL of the second organic compound, the transient EL of the first organic compound, and a mixed film obtained by mixing these materials and observing differences in transient response.

[0161] The electron transport layer 114 is a layer containing a substance having an electron transport property. The substance having an electron transport property is a material having an electron mobility of 1×10 or more at a square root of an electric field strength [V / cm] of 600. −７ cm ２ / Vs or more, preferably 1×10 −６ cm ２A substance having an electron mobility of 1 / Vs or more is preferred. Note that, other substances can be used as long as they have a higher electron transporting property than holes. Note that, as the organic compound, an organic compound having a π-electron-deficient heteroaromatic ring is preferred. As the organic compound having a π-electron-deficient heteroaromatic ring, for example, one or more of an organic compound including a heteroaromatic ring having an azole skeleton, an organic compound including a heteroaromatic ring having a pyridine skeleton, an organic compound including a heteroaromatic ring having a diazine skeleton, and an organic compound including a heteroaromatic ring having a triazine skeleton are preferred.

[0162] As a substance having an electron-transporting property that can be used in the electron-transporting layer 114, the organic compounds exemplified as the organic compounds having an electron-transporting property that are preferably used as a host material in the light-emitting layer 113 can be used in the same way.

[0163] Among the organic compounds listed as organic compounds having electron transport properties that are preferably used as host materials, organic compounds containing a heteroaromatic ring having a diazine skeleton, organic compounds containing a heteroaromatic ring having a pyridine skeleton, and organic compounds containing a heteroaromatic ring having a triazine skeleton are preferred because of their excellent reliability. In particular, organic compounds containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing a heteroaromatic ring having a triazine skeleton have high electron transport properties and contribute to reducing driving voltage. In particular, organic compounds having a phenanthroline skeleton such as mTpPPhen, PnNPhen, and mPPhen2P are preferred, and organic compounds having a phenanthroline dimer structure such as mPPhen2P are more preferred because of their excellent stability.

[0164] The electron transport layer 114 may have a stacked structure. A layer in the electron transport layer 114 having a stacked structure that is in contact with the light-emitting layer 113 may function as a hole-blocking layer. When the electron transport layer in contact with the light-emitting layer is made to function as a hole-blocking layer, it is preferable to use a material whose HOMO level is lower by 0.5 eV or more than the HOMO level of a material contained in the light-emitting layer 113.

[0165] The electron-injection layer 115 may be provided as a layer containing an alkali metal or alkaline earth metal, a compound or complex of an alkali metal or alkaline earth metal, 1,1′-pyridine-2,6-diyl-bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) (abbreviation: hpp2Py), or the like. The electron-injection layer 115 may be formed by incorporating such a compound or complex into a layer made of a substance having an electron-transporting property.

[0166] Alternatively, a charge generation layer 116 may be provided instead of the electron injection layer 115 ( FIG. 1B ). The charge generation layer 116 is a layer capable of injecting holes into a layer in contact with the cathode side of the charge generation layer 116 and electrons into a layer in contact with the anode side of the charge generation layer 116 by applying a potential. The charge generation layer 116 includes at least a P-type layer 117. The P-type layer 117 is preferably formed using the composite material listed above as a material that can constitute the hole injection layer 111. The P-type layer 117 may also be formed by stacking a film containing an acceptor material and a film containing a hole transport material, both of which are materials that constitute the composite material. By applying a potential to the P-type layer 117, electrons are injected into the electron transport layer 114 and holes are injected into the cathode, thereby operating the light-emitting device. Furthermore, since the organic compound of one embodiment of the present invention has a low refractive index, using it for the P-type layer 117 can provide a light-emitting device with excellent external quantum efficiency.

[0167] It is preferable that the charge generating layer 116 be provided with either or both of an electron relay layer 118 and an electron injection buffer layer 119 in addition to the P-type layer 117 .

[0168] The electron relay layer 118 contains at least a substance having electron transport properties and has the function of preventing interaction between the electron injection buffer layer 119 and the P-type layer 117 and smoothly transferring electrons. The LUMO level of the substance having electron transport properties contained in the electron relay layer 118 is preferably located between the LUMO level of the acceptor substance in the P-type layer 117 and the LUMO level of the substance contained in the layer of the electron transport layer 114 that is in contact with the charge generation layer 116. The specific energy level of the LUMO level of the substance having electron transport properties used in the electron relay layer 118 is preferably −5.0 eV or higher, preferably −5.0 eV or higher to −3.0 eV or lower, more preferably −4.30 eV or higher to −3.00 eV or lower, and more preferably −4.30 eV or higher to −3.30 eV or lower, because this can suppress an increase in driving voltage. As the substance having electron transport properties used in the electron relay layer 118, a phthalocyanine-based material or a metal complex having a metal-oxygen bond and an aromatic ligand is preferably used.

[0169] Specific examples of the substance having electron transport properties that can be used in the electron relay layer 118 include diquinoxalino[2,3-a:2′,3′-c]phenazine (abbreviation: HATNA), 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2′,3′-c]phenazine (abbreviation: HATNA-F6), perylene tetracarboxylic acid derivatives such as 3,4,9,10-perylene tetracarboxylic diimide (abbreviation: PTCDI) and 3,4,9,10-perylene tetracarboxylic bis-benzimidazole (abbreviation: PTCBI), (C60-Ih)[5,6]fullerene (abbreviation: C60), and (C70-D5h)[5,6]fullerene (abbreviation: C70). Furthermore, a compound having a heterophane skeleton, which is a cyclophane skeleton containing a heterocycle, can be used. Examples of such a compound include phthalocyanine (abbreviation: H ２Phthalocyanine compounds such as copper phthalocyanine (abbreviated as CuPc), zinc phthalocyanine (abbreviated as ZnPc), cobalt phthalocyanine (abbreviated as CoPc), iron phthalocyanine (abbreviated as FePc), tin phthalocyanine (abbreviated as SnPc), tin oxide phthalocyanine (abbreviated as SnOPc), titanium oxide phthalocyanine (abbreviated as TiOPc), vanadium oxide phthalocyanine (abbreviated as VOPc), and their derivatives can also be used. 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 particularly preferred.

[0170] The electron injection buffer layer 119 can be made of a material with high electron injection properties, such as an alkali metal, an alkaline earth metal, a rare earth metal, or a compound thereof (an alkali metal compound (including an oxide such as lithium oxide, a halide, or a carbonate such as lithium carbonate or cesium carbonate), an alkaline earth metal compound (including an oxide, a halide, or a carbonate), or a rare earth metal compound (including an oxide, a halide, or a carbonate)).

[0171] When the electron-injection buffer layer 119 is formed to contain a substance having electron-transporting properties and a donor substance, examples of the donor substance include alkali metals, alkaline earth metals, rare earth metals, and compounds thereof (alkali metal compounds (including oxides such as lithium oxide, halides, and carbonates such as lithium carbonate and cesium carbonate), alkaline earth metal compounds (including oxides, halides, and carbonates), and rare earth metal compounds (including oxides, halides, and carbonates)), as well as organic compounds such as tetrathianaphthacene (abbreviation: TTN), nickelocene, and decamethylnickelocene. Note that the substance having electron-transporting properties can be formed using the same material as the material constituting the electron-transporting layer 114 described above.

[0172] The second electrode 102 is an electrode including a cathode. The second electrode 102 may have a laminated structure, in which case the layer in contact with the organic compound layer 103 functions as the cathode. Materials that form the cathode include metals, alloys, electrically conductive compounds, and mixtures thereof, each having a small work function (specifically, 3.8 eV or less). 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), and strontium (Sr), and alloys (MgAg, AlLi) and compounds (lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF), etc.) containing these elements. ２ However, by providing the electron injection layer 115 or a thin film of the above-mentioned material having a small work function between the second electrode 102 and the electron transport layer, various conductive materials such as Al, Ag, ITO, indium oxide-tin oxide containing silicon or silicon oxide can be used as the cathode regardless of the magnitude of the work function.

[0173] When the second electrode 102 is formed using a material that is transparent to visible light, a light-emitting device that emits light from the second electrode 102 side can be obtained. Furthermore, by forming a capping layer on the second electrode 102 using a material with a high refractive index (for example, a material having an ordinary refractive index (no) of 1.90 or more at a wavelength of 450 nm, an ordinary refractive index (no) of 1.80 or more at a wavelength of 520 nm, or an ordinary refractive index (no) of 1.75 or more at a wavelength of 630 nm), the light extraction efficiency can be improved. Note that it is preferable to use an organic compound for the capping layer because it is easy to form.

[0174] These conductive materials can be formed into films by dry methods such as vacuum deposition or sputtering, inkjet methods, spin coating methods, etc. Alternatively, they may be formed by wet methods using a sol-gel method, or by wet methods using a paste of a metal material.

[0175] In addition, various methods, whether dry or wet, can be used to form the organic compound layer 103. For example, vacuum deposition, gravure printing, offset printing, screen printing, inkjet printing, spin coating, or the like may be used.

[0176] Furthermore, the above-mentioned electrodes or layers may be formed using different film formation methods.

[0177] Next, an embodiment of a light-emitting device having a configuration in which multiple light-emitting units are stacked (also referred to as a stacked element or a tandem element) will be described with reference to FIG. 1C . This light-emitting device has multiple light-emitting units between an anode and a cathode. One light-emitting unit has a configuration substantially similar to that of the organic compound layer 103 shown in FIG. 1A . In other words, the light-emitting device shown in FIG. 1C is a light-emitting device having multiple light-emitting units, and the light-emitting device shown in FIG. 1A or 1B can be said to be a light-emitting device having one light-emitting unit.

[0178] 1C , a first light-emitting unit 511 and a second light-emitting unit 512 are stacked between a first electrode 501 and a second electrode 502, and a charge generation layer 513 is provided between the first light-emitting unit 511 and the second light-emitting unit 512. The first electrode 501 and the second electrode 502 correspond to the first electrode 101 and the second electrode 102 in FIG. 1A , respectively, and the same explanation as given in the explanation of FIG. 1A can be applied thereto. In addition, the first light-emitting unit 511 and the second light-emitting unit 512 may be composed of the same material or different materials.

[0179] The charge generation layer 513 has a function of injecting electrons into one light-emitting unit and injecting holes into the other light-emitting unit when a voltage is applied between the first electrode 501 and the second electrode 502. That is, in FIG. 1C , when a voltage is applied so that the potential of the anode is higher than the potential of the cathode, the charge generation layer 513 may inject electrons into the first light-emitting unit 511 and inject holes into the second light-emitting unit 512.

[0180] The charge generation layer 513 is preferably formed to have the same structure as the charge generation layer 116 described in FIG. 1B. A composite material of an organic compound and a metal oxide has excellent carrier injection and carrier transport properties, and therefore can achieve low-voltage driving and low-current driving. Note that when the anode side surface of the light-emitting unit is in contact with the charge generation layer 513, the charge generation layer 513 can also serve as a hole injection layer for the light-emitting unit, and therefore the light-emitting unit does not need to be provided with a hole injection layer.

[0181] Furthermore, when the electron injection buffer layer 119 is provided in the charge generation layer 513, the electron injection buffer layer 119 plays the role of an electron injection layer in the light-emitting unit on the anode side, and therefore, it is not necessarily required to form an electron injection layer in the light-emitting unit on the anode side.

[0182] 1C illustrates a light-emitting device having two light-emitting units, but the present invention can be applied to a light-emitting device having three or more stacked light-emitting units. By arranging a plurality of light-emitting units between a pair of electrodes and separating them with a charge generating layer 513, as in the light-emitting device according to this embodiment, it is possible to realize a device that can emit high-luminance light while maintaining a low current density and has a long life. Furthermore, it is possible to realize a light-emitting device that can be driven at a low voltage and consumes low power.

[0183] Furthermore, by making the emission colors of the respective light-emitting units different, it is possible to obtain light emission of a desired color from the light-emitting device as a whole. For example, in a light-emitting device having two light-emitting units, it is possible to obtain a light-emitting device that emits white light as a whole by obtaining red and green emission colors from the first light-emitting unit and blue emission color from the second light-emitting unit. Furthermore, by having the luminescent center substances of the respective light-emitting units exhibit emission colors of the same hue, it is possible to provide a light-emitting device with extremely high current efficiency.

[0184] Furthermore, each layer and electrode such as the organic compound layer 103, the first light-emitting unit 511, the second light-emitting unit 512, and the charge generation layer can be formed by, for example, a vapor deposition method (including a vacuum vapor deposition method), a droplet discharge method (also called an ink-jet method), a coating method, a gravure printing method, etc. Furthermore, they may contain a low-molecular-weight material, a medium-molecular-weight material (including an oligomer and a dendrimer), or a polymer material.

[0185] (Embodiment 3) In this embodiment, a display device manufactured using the light-emitting device described in Embodiments 1 and 2 will be described with reference to Fig. 2. Fig. 2A is a top view showing the display device, and Fig. 2B is a cross-sectional view taken along lines A-B and C-D in Fig. 2A. This display device includes a driver circuit section (source line driver circuit) 601, a pixel section 602, and a driver circuit section (gate line driver circuit) 603, all of which are shown by dotted lines, to control light emission from the light-emitting device. Also, 604 is a sealing substrate, 605 is a sealant, and the inside surrounded by the sealant 605 is a space 607.

[0186] The lead wiring 608 is wiring for transmitting signals input to the source line driver circuit 601 and the gate line driver circuit 603, and receives video signals, clock signals, start signals, reset signals, etc. from an FPC (flexible print circuit) 609, which serves as an external input terminal. Although only the FPC is shown here, a printed wiring board (PWB) may be attached to this FPC. The display device in this specification includes not only the display device itself, but also a state in which an FPC or PWB is attached to it.

[0187] Next, the cross-sectional structure will be described with reference to Fig. 2B. A driver circuit portion and a pixel portion are formed on an element substrate 610, and here, a source line driver circuit 601, which is the driver circuit portion, and one pixel in a pixel portion 602 are shown.

[0188] The element substrate 610 may be made of a substrate made of glass, quartz, organic resin, metal, alloy, semiconductor, or the like, or a plastic substrate made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fluoride), polyester, acrylic resin, or the like.

[0189] The structure of the transistors used in the pixels and the driver circuits is not particularly limited. For example, they may be inverted staggered transistors or staggered transistors. Furthermore, they may be top-gate or bottom-gate transistors. The semiconductor material used for the transistors is not particularly limited, and examples thereof include silicon, germanium, silicon carbide, and gallium nitride. 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.

[0190] The crystallinity of a semiconductor material used for a transistor is not particularly limited, and any of an amorphous semiconductor and a crystalline semiconductor (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor having a crystalline region in part) may be used. The use of a crystalline semiconductor is preferable because it can suppress deterioration of transistor characteristics.

[0191] Here, it is preferable to use an oxide semiconductor for the transistors provided in the pixel and the driver circuit, as well as for semiconductor devices such as transistors used in touch sensors, which will be described later. In particular, it is preferable to use 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.

[0192] The oxide semiconductor preferably contains at least indium (In) or zinc (Zn), and more preferably contains an oxide represented by In-M-Zn-based oxide (M is a metal such as Al, Ti, Ga, Ge, Y, Zr, Sn, La, Ce, or Hf).

[0193] In particular, it is preferable to use, as the semiconductor layer, an oxide semiconductor film which has a plurality of crystal parts whose c-axes are oriented perpendicular to a surface on which the semiconductor layer is formed or a top surface of the semiconductor layer and which has no grain boundaries between adjacent crystal parts.

[0194] By using such a material for the semiconductor layer, fluctuations in electrical characteristics are suppressed, and a highly reliable transistor can be realized.

[0195] Furthermore, a transistor having the above-described semiconductor layer can retain charge stored in a capacitor through the transistor for a long period of time due to its low off-state current. By applying such a transistor to a pixel, it is possible to stop the driver circuit while maintaining the gray level of an image displayed in each display region. As a result, an electronic device with extremely low power consumption can be realized.

[0196] For example, to stabilize the characteristics of a transistor, it is preferable to provide a base film. The base film can be formed as a single layer or a stacked layer using an inorganic insulating film such as a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a silicon nitride oxide film. The base film can be formed by a sputtering method, a CVD (Chemical Vapor Deposition) method (such as a plasma CVD method, a thermal CVD method, or a MOCVD (Metal Organic CVD) method), an ALD (Atomic Layer Deposition) method, a coating method, a printing method, or the like. Note that the base film need not be provided if it is not necessary.

[0197] The FET 623 indicates one of the transistors formed in the drive circuit section 601. The drive circuit may be formed of various CMOS circuits, PMOS circuits, or NMOS circuits. Although this embodiment shows a driver-integrated type in which the drive circuit is formed on a substrate, this is not necessarily required, and the drive circuit may also be formed externally rather than on the substrate.

[0198] Furthermore, 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 of the FET, but is not limited to this, and the pixel portion may be formed by combining three or more FETs and a capacitance element.

[0199] An insulator 614 is formed to cover an end portion of the first electrode 613. Here, the insulator 614 can be formed by using a positive photosensitive acrylic resin film.

[0200] Furthermore, in order to improve the coverage of organic compound layers and the like to be formed later, a curved surface having a curvature is formed at the upper or lower end of the insulator 614. For example, when a positive photosensitive acrylic resin is used as the material for the insulator 614, it is preferable to provide a curved surface having a curvature radius (0.2 μm to 3 μm) only at the upper end of the insulator 614. Furthermore, either a negative photosensitive resin or a positive photosensitive resin can be used as the insulator 614.

[0201] An organic compound layer 616 and a second electrode 617 are formed on the first electrode 613. Here, it is desirable to use a material with a large work function as the material used for the first electrode 613, which functions as an anode. For example, a single layer film such as an ITO film, an indium tin oxide film containing silicon, an indium oxide film containing 2 to 20 wt % zinc oxide, a titanium nitride film, a chromium film, a tungsten film, a Zn film, or a Pt film can be used. It is also possible to use a stacked structure of a titanium nitride film and a film mainly composed of aluminum, or a three-layer structure of a titanium nitride film, a film mainly composed of aluminum, and a titanium nitride film. The stacked structure provides low resistance as a wiring, good ohmic contact, and the first electrode 613 can further function as an anode.

[0202] The organic compound layer 616 is formed by various methods such as a vapor deposition method using a vapor deposition mask, an inkjet method, or a spin coating method. The organic compound layer 616 includes the structures described in Embodiment Mode 1 and Embodiment Mode 2. Other materials constituting the organic compound layer 616 may be low-molecular-weight compounds or high-molecular-weight compounds (including oligomers and dendrimers).

[0203] Furthermore, as a material used for the second electrode 617 formed on the organic compound layer 616 and functioning as a cathode, a material having a small work function (Al, Mg, Li, Ca, or alloys and compounds thereof (MgAg, MgIn, AlLi, etc.)) is preferably used. Note that, when light generated in the organic compound layer 616 is transmitted through the second electrode 617, it is preferable to use a stack of a thin metal thin film and a transparent conductive film (ITO, indium oxide containing 2 to 20 wt % zinc oxide, indium tin oxide containing silicon, zinc oxide (ZnO), etc.) as the second electrode 617.

[0204] Note that a light-emitting device is formed with 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 Mode 1 and Embodiment Mode 2. Note that a pixel portion is formed with a plurality of light-emitting devices, but the display device in this embodiment mode may include both the light-emitting devices described in Embodiment Mode 1 and Embodiment Mode 2 and light-emitting devices having other structures.

[0205] Furthermore, by bonding the sealing substrate 604 to the element substrate 610 with a sealing material 605, a structure is formed in which a light-emitting device 618 is provided in a space 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealing material 605. The space 607 is filled with a filler, and in some cases, the space is filled with an inert gas (nitrogen, argon, etc.), or with a sealing material. A recess is formed in the sealing substrate, and by providing a desiccant therein, deterioration due to the influence of moisture can be suppressed, which is a preferable configuration.

[0206] It is preferable to use epoxy resin or glass frit for the sealing material 605. It is also desirable that these materials are as moisture and oxygen impermeable as possible. In addition, materials that can be used for the sealing substrate 604 include glass substrates, quartz substrates, and plastic substrates made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fluoride), polyester, acrylic resin, etc.

[0207] Although not shown in FIG. 2 , a cap layer and / or a protective film may be provided on the second electrode. Forming the cap layer can improve light extraction efficiency. The cap layer is preferably formed using a material having, for example, an ordinary refractive index (n o ) of 1.90 or more at a wavelength of 450 nm, an ordinary refractive index (n o ) of 1.80 or more at a wavelength of 520 nm, or an ordinary refractive index (n o ) of 1.75 or more at a wavelength of 630 nm. Furthermore, the cap layer is preferably formed by depositing an organic compound by a vapor deposition method, as this method can be easily formed.

[0208] The protective film may be formed of an organic resin film or an inorganic insulating film. In particular, it is preferable to use a material that can be formed using the atomic layer deposition (ALD) method for the protective film. By using the ALD method, it is possible to form a dense protective film with reduced defects such as cracks and pinholes, or with a uniform thickness. Furthermore, it is possible to reduce damage to the processed member when forming the protective film.

[0209] A protective film may be formed so as to cover the exposed portion of the sealing material 605. The protective film may be provided so as to cover the surfaces and side surfaces of the pair of substrates, the exposed side surfaces of the sealing layer, the insulating layer, and the like.

[0210] The protective film can be made of a material that is impermeable to impurities such as water, and therefore can effectively prevent impurities such as water from diffusing from the outside to the inside.

[0211] The protective film may be made of an oxide, nitride, fluoride, sulfide, ternary compound, metal, polymer, or the like. For example, 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; aluminum nitride, hafnium nitride, silicon nitride, tantalum nitride, titanium nitride, niobium nitride, molybdenum nitride, zirconium nitride, or gallium nitride, or the like; titanium and aluminum nitride, titanium and aluminum oxide, aluminum and zinc oxide, manganese and zinc sulfide, cerium and strontium sulfide, erbium and aluminum oxide, or yttrium and zirconium oxide. Aluminum oxide is particularly preferred as the protective film.

[0212] The protective film is preferably formed using a film formation method that provides good step coverage. One such method is the ALD method. For example, by forming the protective film using the ALD method, it is possible to form a uniform protective film with few defects even on surfaces with complex uneven shapes, including the top, side, and back surfaces of the touch panel.

[0213] In this manner, a display device manufactured using the light-emitting device described in Embodiment 1 or 2 can be obtained.

[0214] The display device in this embodiment uses the light-emitting device described in Embodiment 1 and Embodiment 2, and therefore, a display device with excellent characteristics can be obtained. Specifically, the light-emitting devices described in Embodiments 1 and 2 have high emission efficiency, and therefore, a display device with low power consumption can be obtained. Furthermore, the light-emitting devices described in Embodiments 1 and 2 have high reliability, and therefore, a display device with high reliability can be obtained. In addition, the light-emitting devices described in Embodiments 1 and 2 can be light-emitting devices with excellent display quality.

[0215] This embodiment mode can be freely combined with other embodiment modes.

[0216] 3A and 3B, a display device is formed by forming a plurality of light-emitting devices 130 over an insulating layer 175. In this embodiment, a display device according to another embodiment of the present invention will be described in detail.

[0217] The display device 100 has a pixel section 177 in which a plurality of pixels 178 are arranged in a matrix. The pixel 178 has a sub-pixel 110R, a sub-pixel 110G, and a sub-pixel 110B.

[0218] In this specification and the like, when describing matters common to, for example, the subpixels 110R, 110G, and 110B, they may be referred to as the subpixels 110. When describing matters common to other components distinguished by alphabets, they may also be described using symbols without the alphabets.

[0219] The sub-pixel 110R emits red light, the sub-pixel 110G emits green light, and the sub-pixel 110B emits blue light. This allows an image to be displayed in the pixel unit 177. Note that in this embodiment, sub-pixels of three colors, red (R), green (G), and blue (B), are described as an example, but combinations of sub-pixels of other colors may also be used. The number of sub-pixels is not limited to three, and may be four or more. Examples of four sub-pixels include sub-pixels of four colors, R, G, B, and white (W), sub-pixels of four colors, R, G, B, and Y, and sub-pixels of R, G, B, and infrared (IR).

[0220] In this specification, 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.

[0221] 3A shows an example in which subpixels of different colors are arranged side by side in the X direction, and subpixels of the same color are arranged side by side in the Y direction. Note that subpixels of different colors may also be arranged side by side in the Y direction, and subpixels of the same color may also be arranged side by side in the X direction.

[0222] A connection portion 140 and a region 141 may be provided outside the pixel portion 177. When the region 141 is provided, the region 141 is provided between the pixel portion 177 and the connection portion 140. When the region 141 is provided, an organic compound layer is provided in the region 141. Furthermore, a conductive layer 151C is provided in the connection portion 140.

[0223] 3 shows an example in which the region 141 and the connection portion 140 are located on the right side of the pixel portion 177, but the positions of the region 141 and the connection portion 140 are not particularly limited. The region 141 and the connection portion 140 may be singular or plural.

[0224] Fig. 3B is an example of a cross-sectional view taken along dashed line A1-A2 in Fig. 3A. As shown in Fig. 3B, display device 100 has insulating layer 171, conductive layer 172 on insulating layer 171, insulating layer 173 on insulating layer 171 and on conductive layer 172, insulating layer 174 on insulating layer 173, and insulating layer 175 on insulating layer 174. Insulating layer 171 is provided on a substrate (not shown). Insulating layer 175, insulating layer 174, and insulating layer 173 have openings that reach conductive layer 172, and plugs 176 are provided to fill the openings.

[0225] In the pixel section 177, the light-emitting device 130 is provided on the insulating layer 175 and the plug 176. A protective layer 131 is provided to cover the light-emitting device 130. The substrate 120 is bonded to the protective layer 131 by a resin layer 122. Preferably, an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 are provided between adjacent light-emitting devices 130.

[0226] Although multiple cross sections of the inorganic insulating layer 125 and the insulating layer 127 are shown in Figure 3B, 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.

[0227] 3B shows light emitting device 130 as light emitting device 130R, light emitting device 130G, and light emitting device 130B. Light emitting device 130R, light emitting device 130G, and light emitting device 130B emit light of different colors. For example, light emitting device 130R can emit red light, light emitting device 130G can emit green light, and light emitting device 130B can emit blue light. Furthermore, light emitting device 130R, light emitting device 130G, or light emitting device 130B may emit other visible light or infrared light.

[0228] The display device of one embodiment of the present invention can be, for example, a top-emission type in which light is emitted in a direction opposite to a substrate on which a light-emitting device is formed. Note that the display device of one embodiment of the present invention may also be a bottom-emission type.

[0229] The light-emitting device 130R has 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. Note that the common layer 104 may or may not be provided, but it is preferable that the common layer 104 be provided because it can reduce damage to the organic compound layer 103R during processing.

[0230] The light-emitting device 130G has 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. Note that the common layer 104 may or may not be provided, but it is preferable that the common layer 104 be provided because it can reduce damage to the organic compound layer 103G during processing.

[0231] The light-emitting device 130B has a configuration as described in Embodiments 1 and 2. It includes a first electrode 101B (pixel electrode) composed of a conductive layer 151B and a conductive layer 152B, an organic compound layer 103B on the first electrode, a common layer 104 on the organic compound layer 103B, and a second electrode (common electrode) 102 on the common layer. The common layer 104 may or may not be provided, but is preferably provided because it can reduce damage to the organic compound layer 103B during processing. When the common layer 104 is provided, the stacked structure of the organic compound layer 103B and the common layer 104 corresponds to the organic compound layer 103 in Embodiments 1 and 2.

[0232] The common layer 104 is preferably an electron injection layer or an electron transport layer, more preferably an electron injection layer. In addition, when the common layer 104 is an electron transport layer, the electron transport layer preferably has a stacked structure, and it is more preferable that 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.

[0233] Furthermore, since light-emitting device 130R and light-emitting device 130G are also light-emitting devices fabricated through a photolithography process, an increase in drive voltage due to the photolithography process is suppressed, and light-emitting devices with a low drive voltage can be obtained.

[0234] One of the pixel electrode and the common electrode of the light-emitting device 130 functions as an anode, and the other functions as a cathode. In the following description, unless otherwise specified, the pixel electrode functions as an anode and the common electrode functions as a cathode.

[0235] The organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B are each formed as an island for each light-emitting device or for each emitted 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-resolution display device. This makes it possible to prevent crosstalk and realize a display device with extremely high contrast. In particular, a display device with high current efficiency at low brightness can be realized.

[0236] The island-shaped organic compound layer 103 is formed by depositing an organic compound film and processing the organic compound film by photolithography.

[0237] The organic compound layer 103 is preferably provided so as to cover the top and side surfaces of the first electrode (pixel electrode) of the light-emitting device 130. This makes it easier to increase the aperture ratio of the display device 100 compared to a configuration in which the end of the organic compound layer 103 is located inside the end of the pixel electrode. Furthermore, covering the side surfaces of the pixel electrode of the light-emitting device 130 with the organic compound layer 103 can prevent the pixel electrode and the second electrode 102 from coming into contact with each other, thereby preventing short circuits in the light-emitting device 130.

[0238] In the display device of one embodiment of the present invention, the first electrode (pixel electrode) of the light-emitting device preferably has a stacked-layer structure. For example, in the example shown in FIG. 3B , the first electrode of the light-emitting device 130 has a stacked-layer structure of a conductive layer 151 and a conductive layer 152.

[0239] For example, a metal material can be used as the conductive layer 151. Specifically, 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), and neodymium (Nd), as well as alloys containing appropriate combinations of these metals, can also be used.

[0240] An oxide containing one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used for the conductive layer 152. For example, it is preferable to use a conductive oxide containing 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, a work function of 4.0 eV or more, and therefore can be suitably used for the conductive layer 152.

[0241] The conductive layer 151 may have a stacked structure of multiple layers containing different materials, and the conductive layer 152 may have a stacked structure of multiple layers containing different materials. In this case, the conductive layer 151 may include a layer containing a material that can be used for the conductive layer 152, such as a conductive oxide, or the conductive layer 152 may include a layer containing 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 stacked structure of two or more layers, a layer in contact with the conductive layer 152 can be a layer containing a material that can be used for the conductive layer 152.

[0242] Note that the side surface of the conductive layer 151 preferably has a tapered shape. Specifically, the side surface of the conductive layer 151 preferably has a tapered shape with a taper angle of less than 90°. In this case, the conductive layer 152 provided along the side surface of the conductive layer 151 also has a tapered shape. By tapering the side surface of the conductive layer 152, coverage of the organic compound layer 103 provided along the side surface of the conductive layer 152 can be improved.

[0243] Next, an example of a method for manufacturing the display device 100 having the configuration shown in FIG. 3A will be described with reference to FIGS.

[0244] [Fabrication Method Example 1] Thin films (insulating films, semiconductor films, conductive films, etc.) constituting a display device can be formed using a sputtering method, a chemical vapor deposition (CVD) method, a vacuum evaporation method, a pulsed laser deposition (PLD) method, an ALD method, or the like.

[0245] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) 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 knife method, slit coating, roll coating, curtain coating, or knife coating.

[0246] Furthermore, when processing the thin films that constitute the display device, they can be processed using, for example, photolithography.

[0247] In photolithography, the light used for exposure may be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these. Other light sources that can be used include ultraviolet light, KrF laser light, and ArF laser light. Exposure may also be performed by immersion exposure technology. Extreme ultraviolet (EUV) light or X-rays may also be used as the light used for exposure. An electron beam may also be used instead of the light used for exposure.

[0248] The thin film can be etched by dry etching, wet etching, sandblasting, or the like.

[0249] 2A , an insulating layer 171 is formed on a substrate (not shown). Subsequently, conductive layers 172 and 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 layers 172 and 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.

[0250] The substrate may be a substrate having heat resistance sufficient to withstand at least a subsequent heat treatment, such as a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, an organic resin substrate, a single crystal semiconductor substrate made of silicon, silicon carbide, or the like, a polycrystalline semiconductor substrate, a compound semiconductor substrate made of silicon germanium, or the like, or an SOI substrate.

[0251] 4A, openings are formed in the insulating layers 175, 174, and 173, reaching the conductive layer 172. Then, plugs 176 are formed to fill the openings.

[0252] 4A , a conductive film 151f, which will later become conductive layers 151R, 151G, 151B, and 151C, and a conductive film 152f, which will later become conductive layers 152R, 152G, 152B, and 152C, are formed on the plug 176 and the insulating layer 175. The conductive film 151f may be formed of, for example, a metal material. The conductive film 152f may be formed of, for example, an oxide containing one or more elements selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon.

[0253] 4A, a resist mask 191 is formed over the conductive film 152f. The resist mask 191 can be formed by applying a photosensitive material (photoresist) and then performing exposure and development.

[0254] 4B, for example, the conductive films 151f and 152f are removed from regions that do not overlap with the resist mask 191. As a result, the conductive layers 151 and 152 are formed.

[0255] 4C, the resist mask 191 is removed by, for example, ashing using oxygen plasma.

[0256] Subsequently, as shown in FIG. 4D , an insulating film 156f, which will later become insulating layers 156R, 156G, 156B, and 156C, is formed on the conductive layer 152R, the conductive layer 152G, the conductive layer 152B, the conductive layer 152C, and the insulating layer 175.

[0257] The insulating film 156f can be an inorganic insulating film such as an insulating oxide film, an insulating nitride film, an insulating oxynitride film, or an insulating nitride oxide film, for example, a silicon oxynitride film.

[0258] Subsequently, as shown in FIG. 4E, the insulating film 156f is processed to form insulating layers 156R, 156G, 156B, and 156C.

[0259] 5A, the organic compound film 103Rf is formed on the conductive layer 152R, the conductive layer 152G, the conductive layer 152B, and the insulating layer 175. Note that, as shown in FIG. 5A, the organic compound film 103Rf is not formed on the conductive layer 152C.

[0260] Subsequently, as shown in FIG. 5A, a sacrificial film 158Rf and a mask film 159Rf are formed.

[0261] 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.

[0262] The sacrificial film 158Rf is made of a film that is highly resistant to the processing conditions of the organic compound film 103Rf, specifically, a film that has a large etching selectivity with respect to the organic compound film 103Rf.The mask film 159Rf is made of a film that has a large etching selectivity with respect to the sacrificial film 158Rf.

[0263] The sacrificial film 158Rf and the mask film 159Rf are formed at a temperature lower than the heat resistance temperature of the organic compound film 103Rf. The substrate temperature when the sacrificial film 158Rf and the mask film 159Rf are formed is typically 100° C. or higher and 200° C. or lower, preferably 100° C. or higher and 150° C. or lower, and more preferably 100° C. or higher and 120° C. or lower. The light-emitting device of one embodiment of the present invention includes the first compound, and therefore a display device with good display quality can be provided even after a heating step at a higher temperature.

[0264] It is preferable to use a film that can be removed by wet etching or dry etching for the sacrificial film 158Rf and the mask film 159Rf.

[0265] The sacrificial film 158Rf formed on and in contact with the organic compound film 103Rf is preferably formed using a formation method that causes less damage to the organic compound film 103Rf than the mask film 159Rf. For example, the ALD method (Atomic Layer Deposition method) or the vacuum evaporation method is more preferable than the sputtering method.

[0266] The sacrificial film 158Rf and the mask film 159Rf may each be made of one or more of a metal film, an alloy film, a metal oxide film, a semiconductor film, an organic insulating film, an inorganic insulating film, or the like.

[0267] The sacrificial film 158Rf and the mask film 159Rf can be made of a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, or tantalum, or an alloy material containing such a metal material. It is particularly preferable to use a low-melting-point material such as aluminum or silver. Using a metal material capable of blocking ultraviolet rays for one or both of the sacrificial film 158Rf and the mask film 159Rf is preferable because it can prevent the organic compound film 103Rf from being irradiated with ultraviolet rays during pattern exposure, thereby suppressing deterioration of the organic compound film 103Rf.

[0268] Furthermore, for the sacrificial film 158Rf and the mask film 159Rf, metal oxides such as In—Ga—Zn oxide, indium oxide, In—Zn oxide, In—Sn oxide, indium titanium oxide (In—Ti oxide), indium tin zinc oxide (In—Sn—Zn oxide), indium titanium zinc oxide (In—Ti—Zn oxide), indium gallium tin zinc oxide (In—Ga—Sn—Zn oxide), and indium tin oxide containing silicon can be used, respectively.

[0269] In addition, in the above metal oxide, an element M (wherein M is one or more elements selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) may be used instead of gallium.

[0270] The sacrificial film 158Rf and the mask film 159Rf are preferably made of a semiconductor material such as silicon or germanium, which has a high affinity with the semiconductor manufacturing process. Alternatively, compounds containing the semiconductor materials can be used.

[0271] The sacrificial film 158Rf and the mask film 159Rf may be made of various inorganic insulating films, and an oxide insulating film is particularly preferable because it has higher adhesion to the organic compound film 103Rf than a nitride insulating film.

[0272] 5A, a resist mask 190R is formed. The resist mask 190R can be formed by applying a photosensitive material (photoresist) and then performing exposure and development.

[0273] The resist mask 190R is provided in a position overlapping with the conductive layer 152R. The resist mask 190R is preferably provided also in a position overlapping with the conductive layer 152C. This can prevent the conductive layer 152C from being damaged during the manufacturing process of the display device.

[0274] 5B , a resist mask 190R is used to remove a portion of the mask film 159Rf to form a mask layer 159R. The mask layer 159R remains on the conductive layer 152R and the conductive layer 152C. The resist mask 190R is then removed. The mask layer 159R is used as a mask (also referred to as a hard mask) to remove a portion of the sacrificial film 158Rf to form a sacrificial layer 158R.

[0275] By using the wet etching method, damage to the organic compound film 103Rf during processing of the sacrificial film 158Rf and the mask film 159Rf can be reduced compared to when using the dry etching method. When using the wet etching method, it is preferable to use an acid aqueous solution such as a developing solution, an alkaline aqueous solution such as a tetramethylammonium hydroxide aqueous solution (TMAH), a chemical solution using dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture of these.

[0276] Furthermore, when dry etching is used to process the sacrificial film 158Rf, deterioration of the organic compound film 103Rf can be suppressed by not using a gas containing oxygen as the etching gas.

[0277] The resist mask 190R can be removed in the same manner as the resist mask 191.

[0278] 5B, the organic compound film 103Rf is processed to form the organic compound layer 103R. For example, the mask layer 159R and the sacrificial layer 158R are used as a hard mask to remove a portion of the organic compound film 103Rf, thereby forming the organic compound layer 103R.

[0279] 5B, 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 layers 152G and 152B are exposed.

[0280] The organic compound film 103Rf is preferably processed by anisotropic etching, particularly anisotropic dry etching, or wet etching may be used.

[0281] When dry etching is used, deterioration of the organic compound film 103Rf can be suppressed by not using a gas containing oxygen as the etching gas.

[0282] Alternatively, a gas containing oxygen may be used as the etching gas. By using an etching gas containing oxygen, the etching rate can be increased. Therefore, etching can be performed under low power conditions while maintaining a sufficiently high etching rate. This makes it possible to suppress damage to the organic compound film 103Rf. Furthermore, problems such as adhesion of reaction products generated during etching can be suppressed.

[0283] When dry etching is used, for example, H ２ , C.F. ４ , C ４ F ８ , SF ６ , CHF ３ , Cl ２ , H ２ O, BCl ３ It is preferable to use a gas containing one or more of Group 18 elements such as He and Ar as the etching gas. Alternatively, it is preferable to use a gas containing one or more of these elements and oxygen as the etching gas. Alternatively, oxygen gas may be used as the etching gas.

[0284] Subsequently, as shown in FIG. 6A, an organic compound film 103Gf, which will later become the organic compound layer 103G, is formed.

[0285] The organic compound film 103Gf can be formed by the same method as that used to form the organic compound film 103Rf, and can have the same structure as the organic compound film 103Rf.

[0286] Next, as shown in FIG. 6A , a sacrificial film 158Gf and a mask film 159Gf are formed in this order. Then, a resist mask 190G is formed. The materials and forming methods of the sacrificial film 158Gf and the mask film 159Gf are the same as those applicable to the sacrificial film 158Rf and the mask film 159Rf. The materials and forming methods of the resist mask 190G are the same as those applicable to the resist mask 190R.

[0287] The resist mask 190G is provided in a position overlapping with the conductive layer 152G.

[0288] 6B, a resist mask 190G is used to remove a portion of the mask film 159Gf to form a mask layer 159G. The mask layer 159G remains on the conductive layer 152G. The resist mask 190G is then removed. Next, the mask layer 159G is used as a mask to remove a portion of the sacrificial film 158Gf to form a sacrificial layer 158G. Next, the organic compound film 103Gf is processed to form an organic compound layer 103G.

[0289] Subsequently, as shown in FIG. 6C, an organic compound film 103Bf is formed.

[0290] The organic compound film 103Bf can be formed by the same method as that used to form the organic compound film 103Rf, and can have the same structure as the organic compound film 103Rf.

[0291] 6C, a sacrificial film 158Bf and a mask film 159Bf are formed in this order. Then, a resist mask 190B is formed. The materials and forming methods of the sacrificial film 158Bf and the mask film 159Bf are the same as those applicable to the sacrificial film 158Rf and the mask film 159Rf. The materials and forming methods of the resist mask 190B are the same as those applicable to the resist mask 190R.

[0292] The resist mask 190B is provided in a position overlapping with the conductive layer 152B.

[0293] 6D, a resist mask 190B is used to remove a portion of the mask film 159Bf to form a mask layer 159B. The mask layer 159B remains on the conductive layer 152B. The resist mask 190B is then removed. The mask layer 159B is then used as a mask to remove a portion of the sacrificial film 158Bf to form a sacrificial layer 158B. The organic compound film 103Bf is then processed to form the organic compound layer 103B. For example, the mask layer 159B and the sacrificial layer 158B are used as hard masks to remove a portion of the organic compound film 103Bf to form the organic compound layer 103B.

[0294] 6D, a laminated structure of the organic compound layer 103B, the sacrificial layer 158B, and the mask layer 159B remains on the conductive layer 152B, and the mask layers 159R and 159G are exposed.

[0295] It is preferable that the side surfaces of the organic compound layers 103R, 103G, and 103B are perpendicular or substantially perpendicular to the surface on which they are formed. For example, it is preferable that the angle formed between the surface on which they are formed and these side surfaces be 60 degrees or more and 90 degrees or less.

[0296] As described above, the distance between adjacent pairs of the organic compound layers 103R, 103G, and 103B formed using photolithography 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, for example, as the distance between the opposing ends of adjacent pairs of the organic compound layers 103R, 103G, and 103B. By narrowing the distance between the island-shaped organic compound layers in this manner, a display device with high definition and a large aperture ratio can be provided. Furthermore, the distance between the first electrodes of adjacent light-emitting devices can also be narrowed, for example, to 10 μm or less, 8 μm or less, 5 μm or less, 3 μm or less, or 2 μm or less. Note that the distance between the first electrodes of adjacent light-emitting devices is preferably 2 μm or more and 5 μm or less.

[0297] Subsequently, as shown in FIG. 7A, it is preferable to remove the mask layers 159R, 159G, and 159B.

[0298] The mask layer removal process can be performed using the same method as the mask film processing process. In particular, by using a wet etching method, damage to the organic compound layer 103 during the mask layer removal can be reduced compared to when a dry etching method is used.

[0299] The mask layer may also be removed by dissolving it in a polar solvent such as water or alcohol, such as ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin.

[0300] After removing the mask layer, a drying treatment may be performed to remove water adsorbed on the surface. For example, a heat treatment can be performed in an inert gas atmosphere or a reduced pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50°C or higher and 200°C or lower, preferably 60°C or higher and 150°C or lower, and more preferably 70°C or higher and 120°C or lower. A reduced pressure atmosphere is preferred because it allows drying at a lower temperature.

[0301] Subsequently, as shown in FIG. 7B, an inorganic insulating film 125f is formed.

[0302] Subsequently, as shown in FIG. 7C, an insulating film 127f, which will later become the insulating layer 127, is formed on the inorganic insulating film 125f.

[0303] The substrate temperature when forming the inorganic insulating film 125f and the insulating film 127f 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.

[0304] As the inorganic insulating film 125f, it is preferable to form an insulating film having a thickness of 3 nm or more, 5 nm or more, or 10 nm or more, and 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less within the above substrate temperature range.

[0305] The inorganic insulating film 125f is preferably formed by, for example, the ALD method. The ALD method is preferable because it can reduce film formation damage and form a film with high coverage. The inorganic insulating film 125f is preferably formed as an aluminum oxide film by, for example, the ALD method.

[0306] The insulating film 127f is preferably formed by the wet film formation method described above. The insulating film 127f is preferably formed by, for example, spin coating using a photosensitive material, more specifically, using a photosensitive resin composition containing an acrylic resin.

[0307] Subsequently, exposure is performed to expose a portion of the insulating film 127f to visible light or ultraviolet light. The insulating layer 127f is formed in a region sandwiched between any two of the conductive layers 152R, 152G, and 152B, and around the conductive layer 152C.

[0308] The width of the insulating layer 127 to be formed later can be controlled by the exposed region of the insulating film 127f. In this embodiment mode, the insulating layer 127 is processed to have a portion overlapping with the top surface of the conductive layer 151.

[0309] The light used for exposure preferably contains i-line (wavelength 365 nm), and may contain at least one of g-line (wavelength 436 nm) and h-line (wavelength 405 nm).

[0310] Subsequently, as shown in FIG. 8A, development is performed to remove the exposed area of ​​the insulating film 127f, thereby forming an insulating layer 127a.

[0311] 8B, an etching process is performed using the insulating layer 127a as a mask to remove a portion of the inorganic insulating film 125f and thin the film thickness of a portion of the sacrificial layers 158R, 158G, and 158B. This results in the formation of the inorganic insulating layer 125 below the insulating layer 127a. Furthermore, the surfaces of the thin portions of the sacrificial layers 158R, 158G, and 158B are exposed. Hereinafter, the etching process using the insulating layer 127a as a mask may be referred to as the first etching process.

[0312] The first etching treatment can be performed by dry etching or wet etching. Note that it is preferable to form the inorganic insulating film 125f using the same material as the sacrificial layers 158R, 158G, and 158B because the first etching treatment can be performed all at once.

[0313] When dry etching is performed, it is preferable to use a chlorine-based gas. ２ , BCl ３ , SiCl ４ , and CCl ４ The chlorine-based gas may be added with oxygen gas, hydrogen gas, helium gas, argon gas, or the like, either alone or in combination of two or more gases. By using dry etching, thin regions of the sacrificial layers 158R, 158G, and 158B can be formed with good in-plane uniformity.

[0314] The dry etching apparatus may be a dry etching apparatus having a high-density plasma source, such as an inductively coupled plasma (ICP) etching apparatus, or a capacitively coupled plasma (CCP) etching apparatus having parallel plate electrodes.

[0315] Furthermore, it is preferable to perform the first etching process by wet etching. Using the wet etching method can reduce damage to the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B compared to using the dry etching method. For example, the wet etching can be performed using an alkaline solution. For example, TMAH, which is an alkaline solution, can be used for wet etching of an aluminum oxide film. Alternatively, an acid solution containing fluoride can also be used. In this case, the wet etching can be performed by the paddle method. Note that if the inorganic insulating film 125f is formed using the same material as the sacrificial layers 158R, 158G, and 158B, the above-mentioned etching process can be performed simultaneously, which is preferable.

[0316] In the first etching process, the sacrificial layers 158R, 158G, and 158B are not completely removed, and the etching process is stopped when the film thicknesses of the sacrificial layers 158R, 158G, and 158B are reduced. In this manner, by leaving the corresponding sacrificial layers 158R, 158G, and 158B on the organic compound layers 103R, 103G, and 103B, it is possible to prevent the organic compound layers 103R, 103G, and 103B from being damaged in subsequent processes.

[0317] Subsequently, the entire substrate is exposed to visible light or ultraviolet light, and the insulating layer 127a is preferably irradiated with the energy density of the exposure. ２ Larger than 800 mJ / cm ２ It is preferable that the dose is 0 mJ / cm or less. ２ Greater than 500 mJ / cm ２ It is more preferable to perform the following. By performing such exposure after development, the transparency of the insulating layer 127a can be improved in some cases. Furthermore, the substrate temperature required for heat treatment to transform the insulating layer 127a into a tapered shape in a later step can be reduced in some cases.

[0318] Here, the presence of a barrier insulating layer against oxygen (e.g., an aluminum oxide film, etc.) as the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B can reduce the diffusion of oxygen into the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B.

[0319] Next, heat treatment (also referred to as post-baking) is performed. By performing the heat treatment, the insulating layer 127a can be transformed into an insulating layer 127 having tapered side surfaces ( FIG. 8C ). The heat treatment is performed at a temperature lower than the upper temperature limit of the organic compound layer. The heat treatment can be performed at a substrate temperature of 50° C. to 200° C., preferably 60° C. to 150° C., and more preferably 70° C. to 130° C. The heating atmosphere may be an air atmosphere or an inert gas atmosphere. The heating atmosphere may be an atmospheric pressure atmosphere or a reduced-pressure atmosphere. This can improve the adhesion between the insulating layer 127 and the inorganic insulating layer 125 and also improve the corrosion resistance of the insulating layer 127.

[0320] By leaving the sacrificial layers 158R, 158G, and 158B in a thinner state without completely removing them in the first etching treatment, the organic compound layers 103R, 103G, and 103B can be prevented from being damaged and deteriorated in the heat treatment, thereby improving the reliability of the light-emitting device.

[0321] 9A , an etching process is performed using the insulating layer 127 as a mask to remove portions of the sacrificial layers 158R, 158G, and 158B. As a result, openings are formed in the sacrificial layers 158R, 158G, and 158B, respectively, and the top surfaces of the organic compound layers 103R, 103G, 103B, and the conductive layer 152C are exposed. Note that, hereinafter, this etching process may be referred to as a second etching process.

[0322] The end of the inorganic insulating layer 125 is covered with the insulating layer 127. Also, Fig. 9A shows an example 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.

[0323] The second etching process is performed by wet etching. By using wet etching, damage to the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B can be reduced compared to when dry etching is used. Wet etching can be performed using, for example, an alkaline solution or an acidic solution. An aqueous solution is preferably used so that the organic compound layer 103 does not dissolve.

[0324] 9B , a common electrode 155 is formed on the organic compound layer 103R, the organic compound layer 103G, the organic compound layer 103B, the conductive layer 152C, and the insulating layer 127. The common electrode 155 can be formed by a method such as sputtering or vacuum deposition.

[0325] Next, as shown in FIG. 9C , a protective layer 131 is formed on the common electrode 155. The protective layer 131 can be formed by a method such as vacuum deposition, sputtering, CVD, or ALD. By providing a capping layer that can also serve as a capping layer, the protective layer 131 can improve the light extraction efficiency in a top-emission light-emitting device. For example, by using a material with an ordinary refractive index (n o ) of 1.90 or more at a wavelength of 450 nm, an ordinary refractive index (n o ) of 1.80 or more at a wavelength of 520 nm, or an ordinary refractive index (n o ) of 1.75 or more at a wavelength of 630 nm, total reflection of light from the organic compound layer 103 at the capping layer can be suppressed, thereby improving the light extraction efficiency. Furthermore, the capping layer can also serve as a protective layer.

[0326] Furthermore, a sealing film may be provided on the protective layer 131 to prevent the light-emitting device from being exposed to the atmosphere before being incorporated into a display device or a light-emitting device. A material that is less permeable to impurities such as water can be used for the sealing film. Specifically, an alumina oxide film may be provided by the ALD method. After the protective layer 131 is formed, the light-emitting device may be transported to the ALD apparatus in a glove box with a nitrogen atmosphere to prevent exposure to the atmosphere until the sealing film is provided. In this case, the oxygen concentration in the glove box is preferably 100 ppm or less, more preferably 10 ppm or less, and even more preferably 1 ppm or less.

[0327] Subsequently, the substrate 120 is attached to the protective layer 131 using the resin layer 122, whereby a display device can be manufactured. As described above, in the manufacturing method of a display device according to one embodiment of the present invention, the insulating layer 156 is provided so as to have a region overlapping with a side surface of the conductive layer 151, and the conductive layer 152 is formed so as to cover the conductive layer 151 and the insulating layer 156. This can increase the yield of the display device and suppress the occurrence of defects. Note that a display device having a microlens array can also be manufactured by providing a microlens array on the protective layer 131 or the sealing film before attaching the substrate 120, and then attaching the substrate 120.

[0328] As described above, in the manufacturing method of a display device according to one embodiment of the present invention, the island-shaped organic compound layers 103R, 103G, and 103B are formed by forming films over the entire surface and then processing them, rather than using a fine metal mask. This allows the island-shaped layers to be formed with uniform thicknesses. This allows a high-resolution display device or a display device with a high aperture ratio to be realized. Furthermore, even when the resolution or aperture ratio is high and the distance between subpixels is extremely short, the organic compound layers 103R, 103G, and 103B can be prevented from contacting each other in adjacent subpixels. Therefore, leakage current between subpixels can be suppressed. This prevents crosstalk and realizes a display device with extremely high contrast. Furthermore, even in a display device including tandem light-emitting devices manufactured by photolithography, a display device with excellent characteristics can be provided.

[0329] Embodiment 5 In this embodiment, a display device according to one embodiment of the present invention will be described.

[0330] The display device of the present embodiment can be a high-definition display device, and can therefore be used, for example, as a display unit for a wristwatch-type or bracelet-type information terminal (wearable device), as well as a display unit for a wearable device that can be worn on the head, such as a head-mounted display (HMD) for VR, or a glasses-type device for AR.

[0331] 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 in electronic devices having relatively large screens, such as television devices, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as in the display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and sound reproducing devices.

[0332] 10A shows a perspective view of a 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 of the display devices 100B to 100E described below.

[0333] The display module 280 has a substrate 291 and a substrate 292. The display module 280 has a display portion 281. The display portion 281 is a region that displays an image in the display module 280, and is a region where light from each pixel provided in a pixel portion 284 (described later) can be viewed.

[0334] 10B is a perspective view schematically illustrating the configuration on the substrate 291 side. A circuit portion 282, a pixel circuit portion 283 on the circuit portion 282, and a pixel portion 284 on the pixel circuit portion 283 are stacked on the substrate 291. A terminal portion 285 for connecting to the FPC 290 is provided in a portion of the substrate 291 that does not overlap with the pixel portion 284. The terminal portion 285 and the circuit portion 282 are electrically connected by a wiring portion 286 composed of a plurality of wirings.

[0335] The pixel portion 284 has a plurality of periodically arranged pixels 284a. An enlarged view of one pixel 284a is shown on the right side of Fig. 10B. The various structures described in the above embodiments can be applied to the pixel 284a.

[0336] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0337] One pixel circuit 283a is a circuit that controls the driving of a plurality of elements included in one pixel 284a.

[0338] The circuit portion 282 includes a circuit for driving each pixel circuit 283 a of the pixel circuit portion 283. For example, the circuit portion 282 preferably includes one or both of a gate line driver circuit and a source line driver circuit. In addition, the circuit portion 282 may include at least one of an arithmetic circuit, a memory circuit, a power supply circuit, and the like.

[0339] The FPC 290 functions as wiring for supplying a video signal, a power supply potential, or the like from the outside to the circuit portion 282. An IC may be mounted on the FPC 290.

[0340] The display module 280 can be configured such that one or both of the pixel circuit unit 283 and the circuit unit 282 are stacked below the pixel unit 284, thereby making it possible to extremely increase the aperture ratio (effective display area ratio) of the display unit 281.

[0341] Because such a display module 280 has extremely high resolution, it can be suitably used in VR devices such as HMDs or eyeglass-type AR devices. For example, even in a configuration in which the display unit of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display unit 281, so that even if the display unit is enlarged with the lens, the pixels are not visible, allowing for a highly immersive display. Furthermore, the display module 280 is not limited to this, and can be suitably used in electronic devices having relatively small display units.

[0342] Display Device 100A The display device 100A shown in FIG. 11A includes a substrate 301, a light-emitting device 130R, a light-emitting device 130G, a light-emitting device 130B, a capacitor 240, and a transistor 310.

[0343] The substrate 301 corresponds to the substrate 291 in FIGS. 11A and 11B . The transistor 310 is a transistor having a channel formation region in the substrate 301. The substrate 301 can be, for example, a semiconductor substrate such as a single crystal silicon substrate. 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 drain. The insulating layer 314 is provided to cover a side surface of the conductive layer 311.

[0344] An element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301 .

[0345] In addition, an insulating layer 261 is provided to cover the transistor 310 , and a capacitor 240 is provided over the insulating layer 261 .

[0346] The capacitor 240 has 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.

[0347] The conductive layer 241 is provided over the insulating layer 261 and is buried in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source and the drain of the transistor 310 by a plug 271 buried 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 with the conductive layer 241 with the insulating layer 243 interposed therebetween.

[0348] An insulating layer 255 is provided to cover the capacitor 240, an insulating layer 174 is provided on the insulating layer 255, and an insulating layer 175 is provided on the insulating layer 174. Light-emitting device 130R, light-emitting device 130G, and light-emitting device 130B are provided on the insulating layer 175. An insulator is provided in the region between adjacent light-emitting devices.

[0349] An insulating layer 156R is provided to have a region overlapping with a side surface of the conductive layer 151R, an insulating layer 156G is provided to have a region overlapping with a side surface of the conductive layer 151G, and an insulating layer 156B is provided to have a region overlapping with a side surface of the conductive layer 151B. Furthermore, a conductive layer 152R is provided to cover the conductive layer 151R and the insulating layer 156R, a conductive layer 152G is provided to cover the conductive layer 151G and the insulating layer 156G, and a conductive layer 152B is provided 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.

[0350] The conductive layer 151R, the conductive layer 151G, and the conductive layer 151B are electrically connected to one of the source and the drain of the transistor 310 by an insulating layer 243, an insulating layer 255, an insulating layer 174, a plug 256 embedded in 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 plugs.

[0351] Furthermore, a protective layer 131 is provided on the light-emitting devices 130R, 130G, and 130B. A substrate 120 is bonded to the protective layer 131 with a resin layer 122. For details of the components from the light-emitting device 130 to the substrate 120, refer to the fourth embodiment. The substrate 120 corresponds to the substrate 292 in FIG. 10A .

[0352] Fig. 11B is a modified example of the display device 100A shown in Fig. 11A. The display device shown in Fig. 11B has a colored layer 132R, a colored layer 132G, and a colored layer 132B, and the light-emitting device 130 has an area where it overlaps with one of the colored layers 132R, 132G, and 132B. In the display device shown in Fig. 11B, the light-emitting device 130 can emit, for example, white light. Furthermore, 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.

[0353] [Display Device 100B] FIG. 12 shows a perspective view of the display device 100B, and FIG. 12 shows a cross-sectional view of the display device 100C.

[0354] The display device 100B has a configuration in which a substrate 352 and a substrate 351 are bonded together. In Fig. 12, the substrate 352 is indicated by a dashed line.

[0355] The display device 100B includes a pixel portion 177, a connection portion 140, a circuit 356, wiring 355, and the like. Fig. 12 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. 12 can also be called a display module including 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 a substrate or a display device in which an IC is mounted on the substrate is called a display module.

[0356] The connection portion 140 is provided outside the pixel portion 177. There may be one or more connection portions 140. 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.

[0357] The circuit 356 can be, for example, a scanning line driver circuit.

[0358] 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.

[0359] 12 shows an example in which an IC 354 is provided on a substrate 351 by a chip-on-glass (COG) method, a chip-on-film (COF) method, or the like. For example, an IC having a scanning line driver circuit or a signal line driver circuit can be used as the IC 354. Note that the display device 100B and the display module may not include an IC. Alternatively, the IC may be mounted on an FPC by a COF method, for example.

[0360] Figure 13 shows an example of a cross section of the display device 100B in Figure 12, in which a portion of the region including the FPC 353, a portion of the circuit 356, a portion of the pixel portion 177, a portion of the connection portion 140, and a portion of the region including the end portion are cut away, as display device 100C.

[0361] [Display Device 100C] The display device 100C shown in FIG. 13 has, between a substrate 351 and a substrate 352, 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.

[0362] For details of the light emitting device 130R, the light emitting device 130G, and the light emitting device 130B, refer to the fourth embodiment.

[0363] Light-emitting device 130R has conductive layer 224R, conductive layer 151R on conductive layer 224R, and conductive layer 152R on conductive layer 151R. Light-emitting device 130G has conductive layer 224G, conductive layer 151G on conductive layer 224G, and conductive layer 152G on conductive layer 151G. Light-emitting device 130B has conductive layer 224B, conductive layer 151B on conductive layer 224B, and conductive layer 152B on conductive layer 151B.

[0364] The conductive layer 224R is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214. An end of the conductive layer 151R is located outside an end of the conductive layer 224R. An insulating layer 156R is provided to have a region in contact with the side surface of the conductive layer 151R, and a conductive layer 152R is provided to cover the conductive layer 151R and the insulating layer 156R.

[0365] Conductive layer 224G, conductive layer 151G, conductive layer 152G, and insulating layer 156G in light-emitting device 130G, and conductive layer 224B, conductive layer 151B, conductive layer 152B, and insulating layer 156B in light-emitting device 130B are similar to conductive layer 224R, conductive layer 151R, conductive layer 152R, and insulating layer 156R in light-emitting device 130R, and therefore detailed description thereof will be omitted.

[0366] Recesses are formed in the conductive layers 224R, 224G, and 224B so as to cover the openings provided in the insulating layer 214. A layer 128 is buried in the recesses.

[0367] The layer 128 has a function of filling in recesses of the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B and planarizing the surface. Conductive layers 151R, 151G, and 151B, which are electrically connected to the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B, are provided on the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B and the layer 128. Therefore, the regions overlapping with the recesses of the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B can also be used as light-emitting regions, thereby increasing the aperture ratio of the pixel.

[0368] The layer 128 may be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be used as appropriate for the layer 128. In particular, the layer 128 is preferably formed using an insulating material, and more preferably using an organic insulating material. For example, the organic insulating material that can be used for the insulating layer 127 described above can be used for the layer 128.

[0369] A protective layer 131 is provided on the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B. The protective layer 131 and the substrate 352 are bonded via an adhesive layer 142. A light-shielding layer 157 is provided on the substrate 352. A solid sealing structure, a hollow sealing structure, or the like can be applied to seal the light-emitting device 130. In FIG. 13 , the space between the substrate 352 and the substrate 351 is filled with the adhesive layer 142, and a solid sealing structure is applied. Alternatively, the space may be filled with an inert gas (nitrogen, argon, etc.), and a hollow sealing structure may be applied. In this case, the adhesive layer 142 may be provided so as not to overlap with the light-emitting device. Alternatively, the space may be filled with a resin different from the frame-shaped adhesive layer 142.

[0370] 13 shows an example in which the connection portion 140 has a conductive layer 224C obtained by processing the same conductive film as the conductive layers 224R, 224G, and 224B, a conductive layer 151C obtained by processing the same conductive film as the conductive layers 151R, 151G, and 151B, and a conductive layer 152C obtained by processing the same conductive film as the conductive layers 152R, 152G, and 152B. Also, FIG. 13 shows an example in which an insulating layer 156C is provided so as to have a region overlapping with a side surface of the conductive layer 151C.

[0371] The display device 100C is a top-emission type. Light emitted by the light-emitting device is emitted toward the substrate 352. The substrate 352 is preferably made of a material that is highly transparent to visible light. The pixel electrode contains a material that reflects visible light, and the counter electrode (common electrode 155) contains a material that transmits visible light.

[0372] An insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are provided over the substrate 351 in this order. A part of the insulating layer 211 functions as a gate insulating layer for each transistor. A part of the insulating layer 213 functions as a gate insulating layer for each transistor. The insulating layer 215 is provided to cover the transistor. The insulating layer 214 is provided to cover the transistor and functions as a planarization layer. Note that the number of gate insulating layers and the number of insulating layers covering the transistors are not limited, and each may be a single layer or two or more layers.

[0373] The insulating layers 211, 213, and 215 are each preferably formed using an inorganic insulating film.

[0374] The insulating layer 214 that functions as a planarizing layer is preferably an organic insulating layer.

[0375] The transistor 201 and the transistor 205 each include a conductive layer 221 functioning as a gate, an insulating layer 211 functioning as a gate insulating layer, a conductive layer 222a and a conductive layer 222b functioning as a source and a drain, a semiconductor layer 231, an insulating layer 213 functioning as a gate insulating layer, and a conductive layer 223 functioning as a gate.

[0376] A connection portion 204 is provided in a region of the substrate 351 where the substrate 352 does not overlap. In the connection portion 204, a source electrode or a drain electrode of the transistor 201 is electrically connected to the FPC 353 through a conductive layer 166 and a connection layer 242. The conductive layer 166 has an example of a stacked structure including a conductive film obtained by processing the same conductive film as the conductive layers 224R, 224G, and 224B, a conductive film obtained by processing the same conductive film as the conductive layers 151R, 151G, and 151B, and a conductive film obtained by processing the same conductive film as the conductive layers 152R, 152G, and 152B. The conductive layer 166 is exposed on the top surface of the connection portion 204. This allows the connection portion 204 and the FPC 353 to be electrically connected via the connection layer 242.

[0377] It is preferable to provide a light-shielding layer 157 on the surface of the substrate 352 facing the substrate 351. The light-shielding layer 157 can be provided between adjacent light-emitting devices, on the connection section 140, on the circuit 356, etc. In addition, various optical members can be arranged on the outside of the substrate 352.

[0378] The substrate 351 and the substrate 352 can be made of the same material as can be used for the substrate 120 .

[0379] The adhesive layer 142 can be made of a material that can be used for the resin layer 122 .

[0380] The connection layer 242 may be an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like.

[0381] [Display Device 100D] The display device 100D shown in FIG. 14 differs from the display device 100C shown in FIG. 14 mainly in that it is a bottom-emission display device.

[0382] Light emitted from the light-emitting device is emitted toward the substrate 351. A material that is highly transparent to visible light is preferably used for the substrate 351. On the other hand, the light-transmitting property of the material used for the substrate 352 does not matter.

[0383] A light-shielding layer 317 is preferably formed between the substrate 351 and the transistor 201 and between the substrate 351 and the transistor 205. In the example shown in FIG. 14, the light-shielding layer 317 is provided over the substrate 351, the insulating layer 153 is provided over the light-shielding layer 317, and the transistors 201, 205, and the like are provided over the insulating layer 153.

[0384] Light emitting device 130R has conductive layer 121R, conductive layer 126R on conductive layer 121R, and conductive layer 129R on conductive layer 126R.

[0385] Light emitting device 130B has conductive layer 121B, conductive layer 126B on conductive layer 121B, and conductive layer 129B on conductive layer 126B.

[0386] The conductive layers 121R, 121B, 126R, 126B, 129R, and 129B are each made of a material that is highly transparent to visible light. The second electrode 102 is preferably made of a material that reflects visible light.

[0387] Although the light emitting device 130G is not shown in FIG. 14, the light emitting device 130G is also provided.

[0388] Although FIG. 14 and other figures show an example in which the top surface of the layer 128 has a flat portion, the shape of the layer 128 is not particularly limited.

[0389] [Display Device 100D2] The display device 100D2 shown in Fig. 15 is an example of a bottom-emission type display device that differs from the display device 100D shown in Fig. 15. The display device 100D2 differs from the display device 100D in that it has an organic resin layer 180. Note that in the figure, the reference numerals of the same components as those in Fig. 15 may be omitted, and the description in Fig. 15 may be referred to for details.

[0390] 15B shows a top view layout of a pixel 178 (pixel 178a and pixel 178b) having subpixels 110 (subpixels 110R, 110G, 110B, and 110W), and Fig. 15C shows a top view of the organic resin layer 180 in a region where the subpixels 110R and 110G of the pixel 178 are formed. Note that the distance between the light-shielding layers 317 is 110Rw in the light-emitting region of the subpixel 110R.

[0391] As shown in FIG. 15A , organic resin layer 180 is provided on insulating layer 214. As shown in the region surrounded by the dashed dotted line in FIG. 15A and in FIG. 15C , organic resin layer 180 has curved recesses 181 (recesses 181 a and 181 b) at least in the region where the subpixels are formed. Note that recesses 181 may be provided outside the light-emitting region, such as recess 181 c. Providing recess 181 c refracts light emitted in the region overlapping with light-shielding layer 317 or light traveling to the region overlapping with light-shielding layer 317, allowing it to be extracted from the light-emitting region, thereby improving light-emitting efficiency.

[0392] A plurality of recesses 181 may be formed in a matrix. Recesses 181a and 181b may be provided in contact with each other, or may have a flat surface therebetween.

[0393] 15, the recess has a hexagonal top surface shape (FIG. 15C) and a semicircular cross-sectional shape (FIG. 15A), but may have other shapes as needed. For example, the recess may have a polygonal top surface shape such as a triangle, a quadrangle (including a rectangle and a square), a pentagon, or any other polygon with rounded corners, an ellipse, or a circle.

[0394] An insulating layer containing an organic material can be used as the organic resin layer 180. For example, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimideamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenolic resin, precursors of these resins, etc. can be used as the organic resin layer 180. Alternatively, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin can be used as the organic resin layer 180.

[0395] Furthermore, a photosensitive resin can be used as the organic resin layer 180. A photoresist can be used as the photosensitive resin. The photosensitive resin can be a positive-type material or a negative-type material.

[0396] The organic resin layer 180 may contain a material that absorbs visible light. For example, the organic resin layer 180 itself may be made of a material that absorbs visible light, or the organic resin layer 180 may contain a pigment that absorbs visible light. For example, the organic resin layer 180 may be made of 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.

[0397] In addition, the first electrode 101 (the first electrode 101R and the first electrode 101W) is provided on the organic resin layer 180, and the organic compound layer 103 is provided on the first electrode 101. Ends of the first electrode 101 and the organic compound layer 103 may be covered with an insulating layer 127.

[0398] Furthermore, the first electrode 101 formed on the organic resin layer 180 has a recess similar to the recess of the organic resin layer 180. Furthermore, the organic compound layer 103 formed on the first electrode 101 has a recess similar to the recess of the first electrode 101. Furthermore, the common layer 104 formed on the organic compound layer 103 has a recess similar to the recess of the organic compound layer 103. Furthermore, the second electrode 102 formed on the common layer 104 has a recess similar to the recess of the common layer 104. That is, the recesses of the organic resin layer 180, the first electrode 101, the organic compound layer 103, the common layer 104, and the second electrode 102 have a structure in which they overlap one another.

[0399] In addition, a common layer 104 is provided over the organic compound layer 103 and the insulating layer 127, and a second electrode 102 is provided over the common layer 104. A protective layer 131 is provided over the second electrode 102, and the second electrode 102 is bonded to a substrate 352 via an adhesive layer 142.

[0400] Although the light emitting device 130G and the light emitting device 130B are not shown in FIG. 15, the light emitting device 130G and the light emitting device 130B are also provided.

[0401] The light-emitting device of one embodiment of the present invention having the organic resin layer 180 as described above contains the organic compound represented by the general formula (Gh1) in the organic compound layer 103 as described in Embodiment 1. Therefore, due to the effect of the organic resin layer 180 and the effect of the organic semiconductor device using the organic compound of the present application being inseparably integrated, an organic semiconductor device with high light-emitting efficiency can be provided. Therefore, an organic semiconductor device with good reliability, low driving voltage, and low power consumption can be provided.

[0402] [Display Device 100E] The display device 100E shown in FIG. 16 is a modification of the display device 100C shown in FIG. 13, and differs from the display device 100C mainly in that it has colored layers 132R, 132G, and 132B.

[0403] In the display device 100E, the light-emitting device 130 has an area that overlaps one of the colored layers 132R, 132G, and 132B. The colored layers 132R, 132G, and 132B can be provided on the surface of the substrate 352 facing the substrate 351. An end of the colored layer 132R, an end of the colored layer 132G, and an end of the colored layer 132B can overlap the light-shielding layer 157.

[0404] In the display device 100E, the light-emitting device 130 can emit, for example, white light. Furthermore, 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. The display device 100E may be configured such that the colored layers 132R, 132G, and 132B are provided between the protective layer 131 and the adhesive layer 142.

[0405] [Display Device 100E2] The display device 100E2 shown in Fig. 17 is a modified example of the display device 100E shown in Fig. 16, and has microlenses 182 on the colored layers 132R, 132G, and 132B. Note that in the figure, the reference numerals of the same components as those in Fig. 16 may be omitted, and for details, the description in Fig. 16 may be referred to.

[0406] 17B shows a top view layout of a pixel 178 (pixel 178a and pixel 178b) having subpixels 110 (subpixels 110R, 110G, and 110B), and Fig. 17C shows a top view of a microlens 182 in a region where the subpixels 110R and 110G of the pixel 178 are formed. Note that the region where the common electrode 155 and the organic compound layer 103 are in contact has a width 110Gw in the light-emitting region of the subpixel 110G.

[0407] 17A has a planarization film 143 provided on a protective layer 131, and colored layers 132R, 132G, and 132B provided on the planarization film 144. The planarization film 144 is provided so as to cover the colored layers 132R, 132G, and 132B. A microlens 182 is provided on the planarization film 144.

[0408] As shown in FIG. 17C, the microlens 182 may be provided for each sub-pixel in the region where the sub-pixels are formed.

[0409] 17C, the top surface shape of the microlens 182 is shown as a hexagon, but other shapes may be used as needed. For example, the top surface shape of the recess may be a polygon such as a triangle, a quadrangle (including a rectangle and a square), a pentagon, or a polygon with rounded corners, an ellipse, or a circle.

[0410] The microlenses 182 can be formed using the same material as the organic resin layer 180 .

[0411] The light-emitting device of one embodiment of the present invention having the above-described microlens 182 contains the organic compound represented by the general formula (Gh1) in the organic compound layer 103 as described in Embodiment 1. Therefore, an organic semiconductor device with high emission efficiency can be provided due to the effect of the microlens 182 and the effect of the organic semiconductor device using the organic compound of the present invention being inseparably integrated. Therefore, an organic semiconductor device that is highly reliable, has a low driving voltage, and consumes low power can be provided.

[0412] This embodiment mode can be combined with other embodiment modes or examples as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0413] Embodiment 6 In this embodiment, an electronic device according to one embodiment of the present invention will be described.

[0414] The electronic devices of this embodiment include the display device of one embodiment of the present invention in a display portion. The display device of one embodiment of the present invention has low power consumption and high reliability. Therefore, the display device of one embodiment of the present invention can be used in the display portion of various electronic devices.

[0415] Examples of electronic devices include electronic devices with relatively large screens such as television sets, desktop or notebook personal computers, computer monitors, digital signage, large game machines such as pachinko machines, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and sound playback devices.

[0416] An example of a wearable device that can be worn on the head will be described with reference to FIGS. 18A to 18D.

[0417] The electronic device 700A shown in FIG. 18A and the electronic device 700B shown in FIG. 18B each have a pair of display panels 751, a pair of housings 721, a communication unit (not shown), a pair of mounting units 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.

[0418] The display device of one embodiment of the present invention can be applied to the display panel 751. Therefore, the electronic device can be highly reliable.

[0419] Each of the electronic device 700A and the electronic device 700B can project an image displayed on the display panel 751 onto a display area 756 of the optical member 753. Because the optical member 753 is translucent, the user can see the image displayed in the display area superimposed on a transmitted image visible through the optical member 753.

[0420] The electronic device 700A and the electronic device 700B may be provided with a camera capable of capturing an image in front of them as an imaging unit. Furthermore, the electronic device 700A and the electronic device 700B may each be provided with an acceleration sensor such as a gyro sensor, thereby detecting the orientation of the user's head and displaying an image corresponding to that orientation in the display area 756.

[0421] The communication unit has a wireless communication device, and can supply, for example, a video signal via the wireless communication device. Note that instead of or in addition to the wireless communication device, a connector to which a cable through which a video signal and a power supply potential can be connected may be provided.

[0422] Furthermore, the electronic device 700A and the electronic device 700B are provided with batteries, which can be charged wirelessly and / or wired.

[0423] The housing 721 may be provided with a touch sensor module.

[0424] Various touch sensors can be used as the touch sensor module. For example, various types of touch sensors can be used, such as a capacitance type, a resistive film type, an infrared type, an electromagnetic induction type, a surface acoustic wave type, or an optical type. In particular, it is preferable to use a capacitance type or an optical type sensor in the touch sensor module.

[0425] The electronic device 800A shown in Figure 18C and the electronic device 800B shown in Figure 18D 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.

[0426] The display device of one embodiment of the present invention can be applied to the display portion 820. Therefore, the electronic device can have high reliability.

[0427] The display unit 820 is provided inside the housing 821 at a position that can be viewed through the lens 832. In addition, by displaying different images on the pair of display units 820, it is possible to perform three-dimensional display using parallax.

[0428] It is preferable that electronic device 800A and electronic device 800B each have a mechanism that allows the left and right positions of lens 832 and display unit 820 to be adjusted so that they are optimally positioned according to the position of the user's eyes.

[0429] The mounting portion 823 allows the user to mount the electronic device 800A or the electronic device 800B on the head.

[0430] The imaging unit 825 has a function of acquiring external information. 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. Furthermore, multiple cameras may be provided to support multiple angles of view, such as telephoto and wide-angle.

[0431] The electronic device 800A may have a vibration mechanism that functions as a bone conduction earphone.

[0432] The electronic device 800A and the electronic device 800B may each have an input terminal to which a cable can be connected for supplying a video signal from a video output device or the like and power for charging a battery provided in the electronic device.

[0433] The electronic device of one embodiment of the present invention may have a function of wirelessly communicating with the earphone 750 .

[0434] 18B includes earphone unit 727. A portion of the wiring connecting earphone unit 727 and the control unit may be disposed inside housing 721 or attachment unit 723.

[0435] 18D includes an earphone unit 827. For example, the earphone unit 827 and the control unit 824 may be configured to be connected to each other by wire.

[0436] As described above, as electronic devices according to one embodiment of the present invention, both glasses-type devices (such as the electronic devices 700A and 700B) and goggle-type devices (such as the electronic devices 800A and 800B) are suitable.

[0437] The electronic device 6500 shown in FIG. 19A is a portable information terminal that can be used as a smartphone.

[0438] The electronic device 6500 includes a housing 6501, a display portion 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, a light source 6508, and the like. The display portion 6502 has a touch panel function.

[0439] The display device of one embodiment of the present invention can be applied to the display portion 6502. Therefore, the electronic device can have high reliability.

[0440] FIG. 19B is a schematic cross-sectional view including the end of the housing 6501 on the microphone 6506 side.

[0441] A light-transmitting protective member 6510 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 the space surrounded by the housing 6501 and the protective member 6510.

[0442] A display panel 6511, an optical member 6512, and a touch sensor panel 6513 are fixed to the protective member 6510 by adhesive layers (not shown).

[0443] In a region outside the display portion 6502, a part of the display panel 6511 is folded back, and an FPC 6515 is connected to the folded back part. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on a printed circuit board 6517.

[0444] The display device of one embodiment of the present invention can be applied to the display panel 6511. Therefore, an extremely lightweight electronic device can be realized. Furthermore, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be mounted thereon while keeping the thickness of the electronic device small. Furthermore, by folding back a part of the display panel 6511 and arranging a connection portion with the FPC 6515 on the back side of the pixel portion, an electronic device with a narrow frame can be realized.

[0445] 19C shows an example of a television set. A television set 7100 has a display portion 7000 built into a housing 7171. Here, the housing 7171 is supported by a stand 7173.

[0446] The display device of one embodiment of the present invention can be applied to the display portion 7000. Therefore, the electronic device can have high reliability.

[0447] The television set 7100 shown in FIG. 19C can be operated using an operation switch provided on the housing 7171 and a separate remote control 7151 .

[0448] 19D shows an example of a laptop personal computer 7200. The laptop personal computer 7200 includes a housing 7211, a keyboard 7212, a pointing device 7213, and an external connection port 7214. The housing 7211 includes a display portion 7000.

[0449] The display device of one embodiment of the present invention can be applied to the display portion 7000. Therefore, the electronic device can have high reliability.

[0450] 19E and 19F show an example of digital signage that can be used in shop windows, showcases, and the like.

[0451] 19E includes a housing 7301, a display portion 7000, and a speaker 7303. The digital signage 7300 may further include an LED lamp, operation keys (including a power switch or an operation switch), a connection terminal, various sensors, a microphone, and the like.

[0452] 19F shows a digital signage 7400 attached to a cylindrical pillar 7401. The digital signage 7400 has a display unit 7000 provided along the curved surface of the pillar 7401.

[0453] 19E and 19F, the display device of one embodiment of the present invention can be applied to the display portion 7000. Therefore, the electronic device can have high reliability.

[0454] The larger the display unit 7000, the more information can be provided at one time. Also, the larger the display unit 7000, the more easily it will attract people's attention, which can increase the advertising effectiveness of, for example, advertisements.

[0455] In particular, when the display device of one embodiment of the present invention is used for advertisements using the digital signage 7400 shown in Figures 19E and 19F, the degree of freedom of expression can be increased by using a light-transmitting panel. For example, a light-transmitting display device can be manufactured by using wiring and a support member using a conductive film that transmits visible light and adjusting the distance between pixel electrodes. Furthermore, when the pillars 7401 are made of tempered glass or the like, the display device can also be used as a showcase.

[0456] In addition to the wiring and the support member using the conductive film that transmits visible light, the tandem light-emitting device according to one embodiment of the present invention can increase the luminance per pixel. That is, even if the aperture ratio of the display device is small, good display is possible, and the light transmittance in the display portion of the display device can be increased. Therefore, the tandem light-emitting device according to one embodiment of the present invention is suitable as a light-transmitting display device.

[0457] Furthermore, as shown in Figures 19E and 19F, it is preferable that the digital signage 7300 or the digital signage 7400 be able to wirelessly connect with an information terminal 7311 or an information terminal 7411 such as a smartphone carried by a user.

[0458] The electronic device shown in Figures 20A to 20G has a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), a connection terminal 9006, a sensor (including a function to measure 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.

[0459] 20A to 20G have various functions, such as a function to display various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function to display a calendar, date, time, etc., a function to control processing using various software (programs), a wireless communication function, a function to read and process programs or data recorded on a recording medium, etc.

[0460] The electronic devices shown in FIGS. 20A to 20G will be described in detail below.

[0461] FIG. 20A is a perspective view showing a mobile information terminal 9171. The mobile information terminal 9171 can be used as, for example, a smartphone. Note that the mobile information terminal 9171 may be provided with a speaker 9003, a connection terminal 9006, a sensor 9007, or the like. The mobile information terminal 9171 can display text and image information on multiple surfaces. FIG. 20A shows an example in which three icons 9050 are displayed. Information 9051, indicated by a dashed rectangle, can also be displayed on another surface of the display unit 9001. Examples of the information 9051 include notifications of incoming emails, SNS messages, phone calls, etc., the title of the email or SNS message, the sender's name, the date and time, the remaining battery level, and radio wave intensity. Alternatively, the icon 9050 or the like may be displayed in the position where the information 9051 is displayed.

[0462] 20B is a perspective view showing a mobile information terminal 9172. The mobile information terminal 9172 has a function of displaying information on three or more surfaces of the display portion 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different surfaces. For example, a user can check information 9053 displayed in a position that can be observed from above the mobile information terminal 9172 while the mobile information terminal 9172 is stored in a breast pocket of clothes.

[0463] 20C is a perspective view showing a tablet terminal 9173. The tablet terminal 9173 is capable of executing various applications such as mobile phone calls, e-mail, document browsing and creation, music playback, internet communication, and computer games, for example. The tablet terminal 9173 has a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front side of a housing 9000, operation keys 9005 as operation buttons on the left side of the housing 9000, and a connection terminal 9006 on the bottom.

[0464] FIG. 20D is a perspective view showing a wristwatch-type mobile information terminal 9200. The mobile information terminal 9200 can be used as, for example, a smart watch (registered trademark). The mobile information terminal 9200 may have an operation key 9005 as an operation button on the left side of the housing 9000 and a sensor 9007 on the bottom. Although the curved bangle-type housing 9000 is shown as an example, the housing 9000 may be attached to a belt or the like. The display surface of the display unit 9001 is curved, and a display can be performed along the curved display surface. The power storage device 9004 may be curved along the housing 9000. The power storage device 9004 is flexible and can be bent according to changes in shape when attached or detached. A charging control IC connected to the power storage device 9004 may be included. The mobile information terminal 9200 can also perform hands-free conversations by communicating with, for example, a wireless headset. The portable information terminal 9200 can also wirelessly transmit data to and from other information terminals and can be charged by wireless power supply. Note that data transmission and charging may be performed by wire using a connection terminal 9006 provided on the housing 9000.

[0465] 20E to 20G are perspective views showing a foldable mobile information terminal 9201. Also, FIG. 20E is a perspective view of the mobile information terminal 9201 in an unfolded state, FIG. 20G is a perspective view of the mobile information terminal 9201 in a folded state, and FIG. 20F is a perspective view of a state in the process of changing from one of FIG. 20E and FIG. 20G to the other. The mobile information terminal 9201 is highly portable when folded, and has a seamless, wide display area when unfolded, providing excellent visibility of the display. The display portion 9001 of the mobile information terminal 9201 is supported by three housings 9000 connected by hinges 9055. For example, the display portion 9001 can be bent with a curvature radius of 0.1 mm or more and 150 mm or less.

[0466] This embodiment mode can be combined with other embodiment modes or examples as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0467] In this example, a manufacturing method and characteristics of a light-emitting device 1 according to one embodiment of the present invention and comparative light-emitting devices 1-1 and 1-2 will be described in detail. The structural formulae of main compounds used in the light-emitting device 1, the comparative light-emitting device 1-1, and the comparative light-emitting device 1-2 are shown below.

[0468]

[0469] (Method for Fabricating Light-Emitting Device 1) First, indium tin oxide containing silicon oxide (ITSO) was deposited to a thickness of 110 nm on a glass substrate by sputtering to form a first electrode 101 having a size of 2 mm x 2 mm. The first electrode 101 functions as an anode.

[0470] Next, the surface of the substrate was washed with water as a pretreatment for forming a light-emitting device on the substrate.

[0471] After that, about 1 × 10 −４ The substrate was introduced into a vacuum deposition apparatus whose inside had been reduced in pressure to 100 Pa, and vacuum baked at 170° C. for 30 minutes in a heating chamber of the vacuum deposition apparatus, and then the substrate was allowed to cool for about 30 minutes.

[0472] 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. N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF) represented by the above structural formula (i) and an electron acceptor material (OCHD-003) having a molecular weight of 672 and containing fluorine were co-deposited by a deposition method to a thickness of 10 nm on the inorganic insulating film and the first electrode 101 in a weight ratio of 1:0.03 (= PCBBiF:OCHD-003), thereby forming a hole injection layer 111.

[0473] On the hole injection layer 111, PCBBiF was evaporated to a thickness of 90 nm to form a first hole transport layer, and then N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP) represented by the above structural formula (ii) was evaporated to a thickness of 10 nm to form a second hole transport layer, thereby forming the hole transport layer 112. Note that the second hole transport layer also functions as an electron blocking layer.

[0474] Subsequently, on the hole transport layer 112, 1-[10-(phenyl-2,3,4,5,6-d ５ )-9-anthracenyl]benzo[b]naphtho[2,3-d]furan (abbreviation: Bnf(II)PhA-02-d ５ ), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviation: α,β-ADN) represented by the above structural formula (iv), 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 (v) were mixed in a weight ratio of 0.5:0.5:0.015 (=Bnf(II)PhA-02-d ５ The light-emitting layer 113 was formed by co-evaporation of a fluorescent substance, a first organic compound, and a second organic compound, which is one embodiment of the present invention.

[0475] Thereafter, 2-(biphenyl-4-yl)-4-phenyl-6-(spiro[9H-fluorene-9,9′-[9H]xanthene]-2′-yl)-1,3,5-triazine (abbreviation: BP-SFxTzn) represented by the structural formula (vi) above was evaporated to a thickness of 10 nm to form a first electron transport layer, and subsequently 2,2′-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P) represented by the structural formula (vii) above was evaporated to a thickness of 15 nm to form a second electron transport layer, thereby forming an electron transport layer 114.

[0476] Subsequently, lithium fluoride (LiF) was evaporated to a thickness of 1 nm to form the electron injection layer 115, and then aluminum (Al) was evaporated to a thickness of 200 nm to form the second electrode 102.

[0477] Next, in a glove box with a nitrogen atmosphere, the light-emitting device was sealed with a glass substrate to prevent it from being exposed to the atmosphere (a UV-curable sealant was applied around the element, UV was irradiated only onto the sealant without irradiating the light-emitting device, and heat treatment was performed at 80°C under atmospheric pressure for 1 hour), thereby forming light-emitting device 1.

[0478] (Method for producing comparative light-emitting device 1-1) Comparative light-emitting device 1-1 was produced by replacing the light-emitting layer of light-emitting device 1 with Bnf(II)PhA-02-d ５ and 3,10PCA2Nbf(IV)-02 in a weight ratio of 1:0.015 (=Bnf(II)PhA-02-d ５ The light-emitting device was fabricated in the same manner as in the light-emitting device 1, except that the layer was formed by co-evaporation so that the composition was: 1, 2, 3, 10PCA2Nbf(IV)-02.

[0479] (Method for manufacturing comparative light-emitting device 1-2) Comparative light-emitting device 1-2 was manufactured in the same manner as light-emitting device 1, except that the light-emitting layer in light-emitting device 1 was formed by co-evaporation of α,β-ADN and 3,10PCA2Nbf(IV)-02 in a weight ratio of 1:0.015 (=α,β-ADN:3,10PCA2Nbf(IV)-02).

[0480] The device structures of the light-emitting device 1, the comparative light-emitting device 1-1, and the comparative light-emitting device 1-2 are shown below.

[0481]

[0482]

[0483] The luminance-current density characteristics of light-emitting device 1, comparative light-emitting device 1-1, and comparative light-emitting device 1-2 are shown in Figure 21, their current efficiency-luminance characteristics in Figure 22, their current density-voltage characteristics in Figure 23, their external quantum efficiency-luminance characteristics in Figure 24, and their electroluminescence spectra in Figure 25.

[0484] Also, 1000 cd / cm ２ The values ​​of voltage, current, current density, CIE chromaticity, current efficiency, and external quantum efficiency around 1000 kJ / cm2 are shown below. The luminance, CIE chromaticity, and electroluminescence spectrum were measured using a spectroradiometer (SR-UL1R, manufactured by Topcon Corporation) at room temperature.

[0485]

[0486] 21 to 25 and Table 3, it can be seen that light-emitting device 1 and comparative light-emitting device 1-2 are light-emitting devices that exhibit a deep blue color with a chromaticity y value of 0.10 or less. Furthermore, the maximum external quantum efficiency exceeded 10%, indicating that these light-emitting devices exhibit good current efficiency and external quantum efficiency. It was also found that light-emitting device 1 exhibited small changes in current efficiency and external quantum efficiency due to changes in luminance.

[0487] When a light-emitting device whose efficiency varies greatly with luminance is used in a display device, if the device is driven without taking this variation into consideration, the luminance of the blue pixel will vary greatly depending on the gradation to be displayed. In this case, it becomes difficult to adjust the luminance with other colors, and it becomes difficult to display with the intended quality. However, since the variation in efficiency with respect to luminance is small in the light-emitting device 1, it is possible to obtain a display with good quality.

[0488] In addition, the current density of the light-emitting device 1 and the comparative light-emitting devices 1-1 and 1-2 was 50 mA / cm ２FIG. 26 shows the normalized luminance time change characteristics in the above case.

[0489] From FIG. 26, it is clear that the light-emitting device 1 and the comparative light-emitting device 1-1 are light-emitting devices exhibiting good reliability.

[0490] The above results demonstrate that the light-emitting device 1 of one embodiment of the present invention is a light-emitting device with excellent characteristics, including excellent light-emitting efficiency, high reliability, and little change in efficiency relative to luminance.

[0491] That is, a light-emitting device according to one embodiment of the present invention, which includes a fluorescent substance, a first organic compound having a polycyclic hydrocarbon, and a second organic compound having a polycyclic hydrocarbon in an light-emitting layer, and which includes a third organic compound having an amine skeleton and a first polycyclic heteroaromatic ring in a hole-transport layer in contact with the light-emitting layer, is found to be a light-emitting device with excellent characteristics, such as good light-emitting efficiency and reliability and little change in efficiency relative to luminance.

[0492] In this example, a manufacturing method and characteristics of a light-emitting device 2 that is a light-emitting device of one embodiment of the present invention and a comparative light-emitting device 2 will be described in detail. The structural formulae of main compounds used in the light-emitting device 2 and the comparative light-emitting device 2 are shown below.

[0493]

[0494] (Method for Fabricating Light-Emitting Device 2) First, indium tin oxide containing silicon oxide (ITSO) was deposited to a thickness of 110 nm on a glass substrate by sputtering to form a first electrode 101 having a size of 2 mm x 2 mm. The first electrode 101 functions as an anode.

[0495] Next, the surface of the substrate was washed with water as a pretreatment for forming a light-emitting device on the substrate.

[0496] After that, about 1 × 10 −４ The substrate was introduced into a vacuum deposition apparatus whose inside had been reduced in pressure to 100 Pa, and vacuum baked at 170° C. for 30 minutes in a heating chamber of the vacuum deposition apparatus, and then the substrate was allowed to cool for about 30 minutes.

[0497] 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. N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF) represented by the above structural formula (i) and an electron acceptor material (OCHD-003) having a molecular weight of 672 and containing fluorine were co-deposited by a deposition method to a thickness of 10 nm on the inorganic insulating film and the first electrode 101 in a weight ratio of 1:0.03 (= PCBBiF:OCHD-003), thereby forming a hole injection layer 111.

[0498] On the hole injection layer 111, PCBBiF was evaporated to a thickness of 90 nm to form a first hole transport layer, and then N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf) represented by the above structural formula (viii) was evaporated to a thickness of 10 nm to form a second hole transport layer, thereby forming the hole transport layer 112. Note that the second hole transport layer also functions as an electron blocking layer.

[0499] Subsequently, on the hole transport layer 112, 1-[10-(phenyl-2,3,4,5,6-d ５ )-9-anthracenyl]benzo[b]naphtho[2,3-d]furan (abbreviation: Bnf(II)PhA-02-d ５ ), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviation: α,β-ADN) represented by the above structural formula (iv), 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 (v) were mixed in a weight ratio of 0.5:0.5:0.015 (=Bnf(II)PhA-02-d ５ The light-emitting layer 113 was formed by co-evaporation of a fluorescent substance, a first organic compound, and a second organic compound, which is one embodiment of the present invention.

[0500] Thereafter, 2-(biphenyl-4-yl)-4-phenyl-6-(spiro[9H-fluorene-9,9′-[9H]xanthene]-2′-yl)-1,3,5-triazine (abbreviation: BP-SFxTzn) represented by the structural formula (vi) above was evaporated to a thickness of 10 nm to form a first electron transport layer, and subsequently 2,2′-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P) represented by the structural formula (vii) above was evaporated to a thickness of 15 nm to form a second electron transport layer, thereby forming an electron transport layer 114.

[0501] Subsequently, lithium fluoride (LiF) was evaporated to a thickness of 1 nm to form the electron injection layer 115, and then aluminum (Al) was evaporated to a thickness of 200 nm to form the second electrode 102.

[0502] Next, in a glove box with a nitrogen atmosphere, the light-emitting device was sealed with a glass substrate to prevent it from being exposed to the atmosphere (a UV-curable sealant was applied around the element, UV was irradiated only onto the sealant without irradiating the light-emitting device, and a heat treatment was performed at 80°C under atmospheric pressure for 1 hour), thereby forming light-emitting device 2.

[0503] (Method for manufacturing comparative light-emitting device 2) Comparative light-emitting device 2 was manufactured in the same manner as light-emitting device 2, except that the second hole transport layer in light-emitting device 2 was formed using 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP) represented by the above structural formula (ix).

[0504] The device structures of the light-emitting device 2 and the comparative light-emitting device 2 are shown below.

[0505]

[0506] The luminance-current density characteristics of light-emitting device 2 and comparative light-emitting device 2 are shown in FIG. 27, the current efficiency-luminance characteristics in FIG. 28, the current density-voltage characteristics in FIG. 29, the external quantum efficiency-luminance characteristics in FIG. 30, and the electroluminescence spectra in FIG. 31.

[0507] Also, 1000 cd / cm ２The values ​​of voltage, current, current density, CIE chromaticity, current efficiency, and external quantum efficiency around 1000 kJ / cm2 are shown below. The luminance, CIE chromaticity, and electroluminescence spectrum were measured using a spectroradiometer (SR-UL1R, manufactured by Topcon Corporation) at room temperature.

[0508]

[0509] 27 to 31 and Table 5 show that light-emitting device 2 and comparative light-emitting device 2 are light-emitting devices that exhibit a deep blue color with a chromaticity y value of 0.10 or less. Furthermore, the maximum external quantum efficiency exceeded 10%, indicating that both devices exhibited favorable characteristics. Furthermore, both light-emitting device 2 and comparative light-emitting device 2 were light-emitting devices with small changes in current efficiency and external quantum efficiency due to changes in luminance.

[0510] In addition, the current density of the light-emitting device 2 and the comparative light-emitting device 2 was 50 mA / cm ２ The normalized luminance time change characteristics in this case are shown in FIG.

[0511] As can be seen from Figure 32, light-emitting device 2 is a light-emitting device that exhibits good reliability, while comparative light-emitting device 2, in which the organic compound contained in the hole transport layer is an organic compound that does not have a polycyclic heteroaromatic ring, is a light-emitting device with very low reliability.

[0512] The above results demonstrate that the light-emitting device 2 of one embodiment of the present invention has favorable characteristics, including high emission efficiency, high reliability, and small change in efficiency relative to luminance.

[0513] That is, a light-emitting device according to one embodiment of the present invention, which includes a fluorescent substance, a first organic compound having a polycyclic hydrocarbon, and a second organic compound having a polycyclic hydrocarbon in an light-emitting layer, and which includes a third organic compound having an amine skeleton and a first polycyclic heteroaromatic ring in a hole-transport layer in contact with the light-emitting layer, has good characteristics in both emission efficiency and reliability. Furthermore, it has been found that a light-emitting device having good characteristics in which the change in efficiency with respect to luminance is small when one of the first organic compound and the second organic compound is an aromatic hydrocarbon and the other is an organic compound having a polycyclic heteroaromatic ring.

[0514] In this example, a manufacturing method and characteristics of a light-emitting device 3 which is a light-emitting device of one embodiment of the present invention and a comparative light-emitting device 3 will be described in detail. Structural formulas of main compounds used in the light-emitting device 3 and the comparative light-emitting device 3 are shown below.

[0515]

[0516] (Method for Fabricating Light-Emitting Device 3) First, indium tin oxide containing silicon oxide (ITSO) was deposited to a thickness of 110 nm on a glass substrate by sputtering to form a first electrode 101 having a size of 2 mm x 2 mm. The first electrode 101 functions as an anode.

[0517] Next, the surface of the substrate was washed with water as a pretreatment for forming a light-emitting device on the substrate.

[0518] After that, about 1 × 10 −４ The substrate was introduced into a vacuum deposition apparatus whose inside had been reduced in pressure to 100 Pa, and vacuum baked at 170° C. for 30 minutes in a heating chamber of the vacuum deposition apparatus, and then the substrate was allowed to cool for about 30 minutes.

[0519] 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. N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF) represented by the above structural formula (i) and an electron acceptor material (OCHD-003) having a molecular weight of 672 and containing fluorine were co-deposited by a deposition method to a thickness of 10 nm on the inorganic insulating film and the first electrode 101 in a weight ratio of 1:0.03 (= PCBBiF:OCHD-003), thereby forming a hole injection layer 111.

[0520] On the hole injection layer 111, PCBBiF was evaporated to a thickness of 90 nm to form a first hole transport layer, and then N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf) represented by the above structural formula (viii) was evaporated to a thickness of 10 nm to form a second hole transport layer, thereby forming the hole transport layer 112. Note that the second hole transport layer also functions as an electron blocking layer.

[0521] Subsequently, on the hole transport layer 112, 7-(phenyl-2,3,4,5,6-d ５ )-1-[10-(phenyl-2,3,4,5,6-d ５ )-9-anthracenyl]dibenzofuran (abbreviation: PDBfPhA-d １０ ), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviation: α,β-ADN) represented by the above structural formula (iv), 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 (v) were mixed in a weight ratio of 0.5:0.5:0.015 (=PDBfPhA-d １０ The light-emitting layer 113 was formed by co-evaporation of a fluorescent substance, a first organic compound, and a second organic compound, which is one embodiment of the present invention.

[0522] Thereafter, 2-(biphenyl-4-yl)-4-phenyl-6-(spiro[9H-fluorene-9,9′-[9H]xanthene]-2′-yl)-1,3,5-triazine (abbreviation: BP-SFxTzn) represented by the structural formula (vi) above was evaporated to a thickness of 10 nm to form a first electron transport layer, and subsequently 2,2′-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P) represented by the structural formula (vii) above was evaporated to a thickness of 15 nm to form a second electron transport layer, thereby forming an electron transport layer 114.

[0523] Subsequently, lithium fluoride (LiF) was evaporated to a thickness of 1 nm to form the electron injection layer 115, and then aluminum (Al) was evaporated to a thickness of 200 nm to form the second electrode 102.

[0524] Next, in a glove box with a nitrogen atmosphere, the light-emitting device was sealed with a glass substrate to prevent it from being exposed to the atmosphere (a UV-curable sealant was applied around the element, UV was irradiated only onto the sealant without irradiating the light-emitting device, and heat treatment was performed at 80°C under atmospheric pressure for 1 hour), thereby forming light-emitting device 3.

[0525] (Method for manufacturing comparative light-emitting device 3) Comparative light-emitting device 3 was manufactured in the same manner as light-emitting device 3, except that the second hole transport layer in light-emitting device 3 was formed using 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP) represented by the above structural formula (ix).

[0526] The device structures of the light-emitting device 3 and the comparative light-emitting device 3 are shown below.

[0527]

[0528] The luminance-current density characteristics of light-emitting device 3 and comparative light-emitting device 3 are shown in FIG. 33, the current efficiency-luminance characteristics in FIG. 34, the current density-voltage characteristics in FIG. 35, the external quantum efficiency-luminance characteristics in FIG. 36, and the electroluminescence spectrum in FIG. 37.

[0529] Also, 1000 cd / cm ２The values ​​of voltage, current, current density, CIE chromaticity, current efficiency, and external quantum efficiency around 1000 kJ / cm2 are shown below. The luminance, CIE chromaticity, and electroluminescence spectrum were measured using a spectroradiometer (SR-UL1R, manufactured by Topcon Corporation) at room temperature.

[0530]

[0531] 33 to 37 and Table 7 show that light-emitting device 3 and comparative light-emitting device 3 are light-emitting devices that exhibit a deep blue color with a chromaticity y value of 0.10 or less. Furthermore, the maximum external quantum efficiency exceeded 10%, indicating that both devices exhibited favorable characteristics. Furthermore, light-emitting device 3 and comparative light-emitting device 3 were light-emitting devices with small changes in current efficiency and external quantum efficiency due to changes in luminance.

[0532] In addition, the current density of the light-emitting device 3 and the comparative light-emitting device 3 was 50 mA / cm ２ The normalized luminance time change characteristics in this case are shown in FIG.

[0533] As can be seen from Figure 38, light-emitting device 3 is a light-emitting device that exhibits good reliability, while comparative light-emitting device 3, in which the organic compound contained in the hole-transport layer is an organic compound that does not have a polycyclic heteroaromatic ring, is a light-emitting device with very low reliability.

[0534] The above results show that the light-emitting device 3 of one embodiment of the present invention has favorable characteristics, such as high emission efficiency, high reliability, and small change in efficiency relative to luminance.

[0535] That is, a light-emitting device according to one embodiment of the present invention, which includes a fluorescent substance, a first organic compound having a polycyclic hydrocarbon, and a second organic compound having a polycyclic hydrocarbon in an light-emitting layer, and which includes a third organic compound having an amine skeleton and a first polycyclic heteroaromatic ring in a hole-transport layer in contact with the light-emitting layer, has good characteristics in both emission efficiency and reliability. Furthermore, it has been found that a light-emitting device having good characteristics in which the change in efficiency with respect to luminance is small when one of the first organic compound and the second organic compound is an aromatic hydrocarbon and the other is an organic compound having a polycyclic heteroaromatic ring.

[0536] In this example, a manufacturing method and characteristics of a light-emitting device 4, which is a light-emitting device of one embodiment of the present invention, and a comparative light-emitting device, a comparative light-emitting device, will be described in detail. The structural formulae of main compounds used in the light-emitting device 4 and the comparative light-emitting device 4 are shown below.

[0537]

[0538] (Method for Fabricating Light-Emitting Device 4) First, indium tin oxide containing silicon oxide (ITSO) was deposited to a thickness of 110 nm on a glass substrate by sputtering to form a first electrode 101 having a size of 2 mm x 2 mm. The first electrode 101 functions as an anode.

[0539] Next, the surface of the substrate was washed with water as a pretreatment for forming a light-emitting device on the substrate.

[0540] After that, about 1 × 10 −４ The substrate was introduced into a vacuum deposition apparatus whose inside had been reduced in pressure to 100 Pa, and vacuum baked at 170° C. for 30 minutes in a heating chamber of the vacuum deposition apparatus, and then the substrate was allowed to cool for about 30 minutes.

[0541] 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. N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF) represented by the above structural formula (i) and an electron acceptor material (OCHD-003) having a molecular weight of 672 and containing fluorine were co-deposited by a deposition method to a thickness of 10 nm on the inorganic insulating film and the first electrode 101 in a weight ratio of 1:0.03 (= PCBBiF:OCHD-003), thereby forming a hole injection layer 111.

[0542] On the hole injection layer 111, PCBBiF was evaporated to a thickness of 90 nm to form a first hole transport layer, and then N-[4-(1-naphthyl)phenyl]-N-(9,9'-spirobi[9H-fluoren]-2-yl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: SFNBBnf) represented by the above structural formula (xi) was evaporated to a thickness of 10 nm to form a second hole transport layer, thereby forming the hole transport layer 112. The second hole transport layer also functions as an electron blocking layer.

[0543] Subsequently, on the hole transport layer 112, 2-(10-phenyl-9-anthracenyl)benzo[b]naphtho[2,3-d]furan (abbreviation: Bnf(II)PhA) represented by the structural formula (xii) above, 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth) represented by the structural formula (xiii) above, and N,N′-diphenyl benzo[b]naphtho[2,3-d]furan (abbreviation: Bnf(II)PhA) represented by the structural formula (v) above were deposited. and -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) were co-evaporated to a thickness of 25 nm so as to achieve a weight ratio of 0.5:0.5:0.015 (=Bnf(II)PhA:αN-βNPAnth:3,10PCA2Nbf(IV)-02). The light-emitting layer 113 has a structure of a light-emitting layer including a fluorescent substance, a first organic compound, and a second organic compound, which is one embodiment of the present invention.

[0544] Thereafter, 2-(biphenyl-4-yl)-4-phenyl-6-(spiro[9H-fluorene-9,9′-[9H]xanthene]-2′-yl)-1,3,5-triazine (abbreviation: BP-SFxTzn) represented by the structural formula (vi) above was evaporated to a thickness of 10 nm to form a first electron transport layer, and subsequently 2,2′-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P) represented by the structural formula (vii) above was evaporated to a thickness of 15 nm to form a second electron transport layer, thereby forming an electron transport layer 114.

[0545] Subsequently, lithium fluoride (LiF) was evaporated to a thickness of 1 nm to form the electron injection layer 115, and then aluminum (Al) was evaporated to a thickness of 200 nm to form the second electrode 102.

[0546] Next, in a glove box with a nitrogen atmosphere, the light-emitting device was sealed with a glass substrate to prevent it from being exposed to the atmosphere (a UV-curable sealant was applied around the element, UV was irradiated only onto the sealant without irradiating the light-emitting device, and heat treatment was performed at 80°C under atmospheric pressure for 1 hour), thereby forming light-emitting device 4.

[0547] (Method for fabricating comparative light-emitting device 4) Comparative light-emitting device 4 was fabricated in the same manner as light-emitting device 4, except that the second hole transport layer in light-emitting device 4 was formed using N,N-bis(biphenyl-4-yl)-9,9′-diphenyl-9H-fluorene-4-amine (abbreviation: BBAFLP(4)) represented by the above structural formula (ivx).

[0548] The device structures of the light-emitting device 4 and the comparative light-emitting device 4 are shown below.

[0549]

[0550] The luminance-current density characteristics of light-emitting device 4 and comparative light-emitting device 4 are shown in Figure 39, the current efficiency-luminance characteristics in Figure 40, the current density-voltage characteristics in Figure 41, the external quantum efficiency-luminance characteristics in Figure 42, and the electroluminescence spectrum in Figure 43.

[0551] Also, 1000 cd / cm ２The values ​​of voltage, current, current density, CIE chromaticity, current efficiency, and external quantum efficiency around 1000 kJ / cm2 are shown below. The luminance, CIE chromaticity, and electroluminescence spectrum were measured using a spectroradiometer (SR-UL1R, manufactured by Topcon Corporation) at room temperature.

[0552]

[0553] 39 to 43 and Table 9 show that light-emitting device 4 and comparative light-emitting device 4 are light-emitting devices that exhibit a deep blue color with a chromaticity y value of 0.10 or less. Among them, light-emitting device 4 has an external quantum efficiency of over 10% over a wide range of chromaticity, and is therefore a light-emitting device that exhibits good current efficiency and external quantum efficiency. Furthermore, light-emitting device 4 is also found to have a low driving voltage.

[0554] In addition, the current density of the light-emitting device 4 and the comparative light-emitting device 4 was 50 mA / cm ２ The normalized luminance time change characteristics are shown in FIG.

[0555] As can be seen from Figure 44, light-emitting device 4 is a light-emitting device that exhibits good reliability, while comparative light-emitting device 4, in which the organic compound contained in the hole-transport layer is an organic compound that does not have a polycyclic heteroaromatic ring, is a light-emitting device with low reliability.

[0556] The above results demonstrate that light-emitting device 4 of one embodiment of the present invention has excellent characteristics, including high emission efficiency, high reliability, and small change in efficiency relative to luminance.

[0557] That is, a light-emitting device according to one embodiment of the present invention, which includes a fluorescent substance, a first organic compound having a polycyclic hydrocarbon, and a second organic compound having a polycyclic hydrocarbon in an light-emitting layer, and which includes a third organic compound having an amine skeleton and a first polycyclic heteroaromatic ring in a hole-transport layer in contact with the light-emitting layer, has favorable characteristics in both emission efficiency and reliability. Furthermore, it has been found that the light-emitting device has favorable characteristics in that the current efficiency and external quantum efficiency are high because both the first organic compound and the second organic compound are aromatic hydrocarbons.

[0558] In this example, a manufacturing method and characteristics of a light-emitting device 5 that is a light-emitting device of one embodiment of the present invention and a comparative light-emitting device 5 will be described in detail. Structural formulas of main compounds used in the light-emitting device 5 and the comparative light-emitting device 5 are shown below.

[0559]

[0560] (Method for Fabricating Light-Emitting Device 5) First, indium tin oxide containing silicon oxide (ITSO) was deposited to a thickness of 110 nm on a glass substrate by sputtering to form a first electrode 101 having a size of 2 mm x 2 mm. The first electrode 101 functions as an anode.

[0561] Next, the surface of the substrate was washed with water as a pretreatment for forming a light-emitting device on the substrate.

[0562] After that, about 1 × 10 −４ The substrate was introduced into a vacuum deposition apparatus whose inside had been reduced in pressure to 100 Pa, and vacuum baked at 170° C. for 30 minutes in a heating chamber of the vacuum deposition apparatus, and then the substrate was allowed to cool for about 30 minutes.

[0563] 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. N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF) represented by the above structural formula (i) and an electron acceptor material (OCHD-003) having a molecular weight of 672 and containing fluorine were co-deposited by a deposition method to a thickness of 10 nm on the inorganic insulating film and the first electrode 101 in a weight ratio of 1:0.03 (= PCBBiF:OCHD-003), thereby forming a hole injection layer 111.

[0564] On the hole injection layer 111, PCBBiF was evaporated to a thickness of 90 nm to form a first hole transport layer, and then N-[4-(1-naphthyl)phenyl]-N-(9,9'-spirobi[9H-fluoren]-2-yl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: SFNBBnf) represented by the above structural formula (xi) was evaporated to a thickness of 10 nm to form a second hole transport layer, thereby forming the hole transport layer 112. The second hole transport layer also functions as an electron blocking layer.

[0565] Subsequently, on the hole transport layer 112, 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth) represented by the structural formula (xiii) above, 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviation: α,β-ADN) represented by the structural formula (iv) above, 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) was co-evaporated to a thickness of 25 nm, with Bnf(II)PhA and α,β-ADN in a weight ratio of 0.5:0.5:0.015 (=Bnf(II)PhA:α,β-ADN:3,10PCA2Nbf(IV)-02). The light-emitting layer 113 has a structure of a light-emitting layer including a fluorescent substance, a first organic compound, and a second organic compound, which is one embodiment of the present invention.

[0566] Thereafter, 2-(biphenyl-4-yl)-4-phenyl-6-(spiro[9H-fluorene-9,9′-[9H]xanthene]-2′-yl)-1,3,5-triazine (abbreviation: BP-SFxTzn) represented by the structural formula (vi) above was evaporated to a thickness of 10 nm to form a first electron transport layer, and subsequently 2,2′-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P) represented by the structural formula (vii) above was evaporated to a thickness of 15 nm to form a second electron transport layer, thereby forming an electron transport layer 114.

[0567] Subsequently, lithium fluoride (LiF) was evaporated to a thickness of 1 nm to form the electron injection layer 115, and then aluminum (Al) was evaporated to a thickness of 200 nm to form the second electrode 102.

[0568] Next, in a glove box with a nitrogen atmosphere, the light-emitting device was sealed with a glass substrate to prevent it from being exposed to the atmosphere (a UV-curable sealant was applied around the element, UV was irradiated only onto the sealant without irradiating the light-emitting device, and heat treatment was performed at 80°C under atmospheric pressure for 1 hour), thereby forming light-emitting device 5.

[0569] (Method for fabricating comparative light-emitting device 5) Comparative light-emitting device 5 was fabricated in the same manner as light-emitting device 5, except that the second hole transport layer in light-emitting device 5 was formed using N,N-bis(biphenyl-4-yl)-9,9′-diphenyl-9H-fluorene-4-amine (abbreviation: BBAFLP(4)) represented by the above structural formula (ivx).

[0570] The device structures of light-emitting device 5 and comparative light-emitting device 5 are shown below.

[0571]

[0572] The luminance-current density characteristics of light-emitting device 5 and comparative light-emitting device 5 are shown in Figure 45, their current efficiency-luminance characteristics in Figure 46, their current density-voltage characteristics in Figure 47, their external quantum efficiency-luminance characteristics in Figure 48, and their electroluminescence spectra in Figure 49.

[0573] Also, 1000 cd / cm ２ The values ​​of voltage, current, current density, CIE chromaticity, current efficiency, and external quantum efficiency around 1000 kJ / cm2 are shown below. The luminance, CIE chromaticity, and electroluminescence spectrum were measured using a spectroradiometer (SR-UL1R, manufactured by Topcon Corporation) at room temperature.

[0574]

[0575] 45 to 49 and Table 11 show that light-emitting device 5 is a light-emitting device that exhibits good current efficiency and external quantum efficiency. It is also found that light-emitting device 5 is a light-emitting device that requires a low driving voltage.

[0576] In addition, the current density of the light-emitting device 5 and the comparative light-emitting device 5 was 50 mA / cm ２ The normalized luminance time change characteristics are shown in FIG.

[0577] As can be seen from Figure 50, light-emitting device 5 is a light-emitting device that exhibits good reliability, while comparative light-emitting device 5, in which the organic compound contained in the hole transport layer is an organic compound that does not have a polycyclic heteroaromatic ring, is a light-emitting device with low reliability.

[0578] The above results demonstrate that light-emitting device 5 of one embodiment of the present invention has excellent characteristics, including high emission efficiency, high reliability, and small change in efficiency relative to luminance.

[0579] That is, a light-emitting device according to one embodiment of the present invention, which includes a fluorescent substance, a first organic compound having a polycyclic hydrocarbon, and a second organic compound having a polycyclic hydrocarbon in an light-emitting layer, and which includes a third organic compound having an amine skeleton and a first polycyclic heteroaromatic ring in a hole-transport layer in contact with the light-emitting layer, has favorable characteristics in both emission efficiency and reliability. Furthermore, it has been found that the light-emitting device has favorable characteristics in that the current efficiency and external quantum efficiency are high because both the first organic compound and the second organic compound are aromatic hydrocarbons.

[0580] Reference Example This reference example describes a synthesis method for N-[4-(1-naphthyl)phenyl]-N-(9,9'-spirobi[9H-fluoren]-2-yl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: SFNBBnf) (specific example (339)) used in the examples. The structural formula of SFNBBnf is shown below.

[0581]

[0582] <Step 1: Synthesis of N-(9,9'-spirobi[9H-fluoren]-2-yl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine> 6.6 g (20 mmol) of 9,9'-spirobi[9H-fluoren]-2-amine and 8.4 g (20 mmol) of 6-phenyl-8-iodobenzo[b]naphtho[1,2-d]furan were added to a 200 mL three-neck flask. After replacing the atmosphere in the flask with nitrogen, 5.8 g (60 mmol) of sodium tert-butoxide and 100 mL of toluene were added. The mixture was degassed by stirring under reduced pressure. Tri-tert-butylphosphine (10 wt % hexane solution) (abbreviated as P(tBu)) was added to the mixture. ３ ) 1.3 mL (0.40 mmol) and bis(dibenzylideneacetone)palladium(0) (abbreviation: Pd(dba) ２ 115 mg (0.20 mmol) of hexane / ethyl acetate (hexane:ethyl acetate) was added to the resulting mixture and stirred at 120°C for 6 hours. After stirring, toluene was added to the resulting mixture and heated and stirred at 100°C. This mixture was suction filtered at the same temperature through alumina, Celite (Fujifilm Wako Pure Chemical Industries, Ltd., catalog number: 537-02305), and Florisil (Wako Pure Chemical Industries, Ltd., catalog number: 066-05265). The resulting filtrate was concentrated, and the resulting solid was purified by silica gel column chromatography (the developing solvent was gradually changed from hexane:ethyl acetate = 7:1 to 3:1), yielding a solid containing the target product. The resulting solid was dissolved in toluene, and ethanol was added to the toluene solution. The precipitated solid was collected by suction filtration, yielding 6.6 g of the target pale yellow solid in a 53% yield. The synthesis scheme for Step 1 is shown below.

[0583]

[0584] <Step 2: Synthesis of SFNBBnf> 3.5 g (5.6 mmol) of N-(9,9'-spirobi[9H-fluoren]-2-yl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine obtained in Step 1 and 1.67 g (5.6 mmol) of 1-(4-bromophenyl)naphthalene were added to a 200 mL three-neck flask. After replacing the atmosphere in the flask with nitrogen, 1.6 g (17 mmol) of sodium tert-butoxide (abbreviation: tBuONa) and 30 mL of toluene were added. This mixture was degassed by stirring under reduced pressure. Tri-tert-butylphosphine (10 wt % hexane solution) (abbreviation: P(tBu) ３ ) 0.30 mL (0.11 mmol) and bis(dibenzylideneacetone)palladium(0) (abbreviation: Pd(dba) ２ 30 mg (56 μmol) of hexane (H2SO4) was added to the resulting mixture and stirred at 120°C for 7 hours. After stirring, toluene was added to the resulting mixture and heated and stirred at 100°C. This mixture was suction filtered at the same temperature through alumina, Celite (Wako Pure Chemical Industries, Ltd., catalog number: 537-02305), and Florisil (Wako Pure Chemical Industries, Ltd., catalog number: 066-05265). The resulting filtrate was concentrated, and the resulting solid was purified by liquid chromatography to obtain a solid containing the target substance. This solid was purified by silica gel column chromatography (the developing solvent was gradually changed from hexane:ethyl acetate = 7:1 to 4:1), yielding 1.1 g of the target pale yellow solid in a yield of 24%.

[0585] The obtained solid was purified by train sublimation. The sublimation purification was carried out by heating the solid at 320°C under a pressure of 3.2 Pa for 19 hours while flowing argon at 10 mL / min. After sublimation purification, 0.81 g of the target solid was obtained with a recovery rate of 74%. The synthesis scheme of Step 2 is shown below.

[0586]

[0587] As described above, SFNBBnf was synthesized.

[0588] The obtained solid １The results of H NMR measurement are shown below, which confirmed that SFNBBnf was obtained in this synthesis example.

[0589] １ H NMR (dichloromethane-d ２ , 500MHz, 22°C): δ = 8.61 (d, J = 8.0Hz, 1H), 8.14 (dd, J = 8.0Hz, 1.0Hz, 1H), 8 .10 (d, J=8.0Hz, 1H), 8.09 (s, 1H), 7.95 (d, J=8.0Hz, 1H), 7.91-7.83 (m, 4 H), 7.74 (dt, J = 7.5Hz, 1.0Hz, 1H), 7.67 (d, J = 7.5Hz, 2H), 7.60 (dt, J = 7.5 Hz, 1.0Hz, 1H), 7.55-7.47 (m, 4H), 7.44-7.33 (m, 7H), 7.29-7.21 (m, 4H), 7 .17-7.13 (m, 4H), 7.04 (dt, J=8.0Hz, 1.0Hz, 1H), 6.83 (dt, J=7.0Hz, 1.5H) z, 2H), 6.65 (d, J = 7.0Hz, 2H), 6.59 (d, J = 8.0Hz, 1H), 6.43 (d, J = 2.5Hz, 1H)

[0590] 100A: display device, 100B: display device, 100C: display device, 100D: display device, 100E: display device, 100: display device, 101: first electrode, 101B: first electrode, 101G: first electrode, 101R: first electrode, 101W: first electrode, 102: second electrode, 103B: organic compound layer, 103G: organic compound layer, 103R: organic compound layer, 103: organic compound layer, 104: common layer, 110B: subpixel, 110G: subpixel, 110R: subpixel, 110W: subpixel, 110: subpixel, 111: hole injection layer, 121B: conductive layer, 121R: conductive conductive layer, 112: hole transport layer, 113: light-emitting layer, 114: electron transport layer, 115: electron injection layer, 116: charge generation layer, 117: P-type layer, 118: electron relay layer, 119: electron injection buffer 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, 131: protective layer, 132B: Colored layer, 132G: colored layer, 132R: colored layer, 140: connecting portion, 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 portion, 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 portion, 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: capacitor, 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 portion, 282: circuit portion, 283a: Pixel circuit, 283: pixel circuit section, 284a: pixel, 284: pixel section, 285: terminal section, 286: wiring section, 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 electrode, 502: second electrode, 511: first light-emitting unit, 512: second light-emitting unit, 513: charge generation layer, 601: source line driving circuit, Drive circuit section, 602: pixel section, 603: gate line drive circuit, 604: sealing substrate, 605: sealant, 607: space, 608: routing wiring, 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: wearing section, 727: earphone section, 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 unit, 823: wearing unit, 824: control unit, 825: imaging unit, 827: earphone unit, 832: lens, 1000: insulating layer, 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 device, 7151: remote control device, 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, 7400: digital signage page, 7401: pillar, 7411: information terminal, 9000: housing, 9001: display unit, 9002: camera, 9003: speaker, 9005: operation keys, 9006: connection terminal, 9007: sensor, 9008: microphone, 9050: icon, 9051: information, 9052: information, 9053: information, 9054: information, 9055: hinge, 9171: mobile information terminal, 9172: mobile information terminal, 9173: tablet terminal, 9200: mobile information terminal, 9201: mobile information terminal,

Claims

a first electrode; a second electrode; and a light-emitting layer; a first layer; the light-emitting layer is located between the first electrode and the second electrode; the first layer is in contact with the light-emitting layer, the light-emitting layer includes a fluorescent material, a first organic compound, and a second organic compound; the first layer comprises a third organic compound; the first organic compound has a first polycyclic hydrocarbon; the second organic compound has a second polycyclic hydrocarbon; The third organic compound has an amine skeleton and a first polycyclic heteroaromatic ring. In claim 1, the first polycyclic hydrocarbon is a substituted or unsubstituted aromatic hydrocarbon having 6 to 22 carbon atoms, A light-emitting device, wherein the second polycyclic hydrocarbon is a substituted or unsubstituted aromatic hydrocarbon having 6 to 22 carbon atoms. In claim 1, A light-emitting device, wherein the first polycyclic hydrocarbon and the second polycyclic hydrocarbon have an anthracene skeleton. In claim 1, A light-emitting device, wherein the first polycyclic hydrocarbon and the second polycyclic hydrocarbon are substituted or unsubstituted anthracenyl groups. In claim 1, A light-emitting device wherein the first polycyclic hydrocarbon and the second polycyclic hydrocarbon are the same. In claim 1, The light-emitting device, wherein the first polycyclic hydrocarbon and the second polycyclic hydrocarbon are anthracenyl groups. In claim 1, the first organic compound is an aromatic hydrocarbon; The light-emitting device wherein the second organic compound further comprises a second polycyclic heteroaromatic ring. In claim 1, A light-emitting device wherein the first organic compound and the second organic compound are both aromatic hydrocarbons.

10. The light-emitting device of claim 1, wherein one or both of the first organic compound and the second organic compound are deuterated. In claim 1, The light-emitting device, wherein the first organic compound and the second organic compound are each independently an organic compound represented by the following general formula (G0): (However, in general formula (G0), R １０１ ~R １１０ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted branched or linear alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 22 carbon atoms, and a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms, and the first organic compound and the second organic compound are different organic compounds. In claim 1, The light-emitting device, wherein the first organic compound is an organic compound represented by the following general formula (G1): (In general formula (G1), R １ ~R １０ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted branched or linear alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 22 carbon atoms. In claim 1, The light-emitting device, wherein the second organic compound is an organic compound represented by the following general formula (G2): (In general formula (G2), R １１ ~R ２０ each independently represents hydrogen (including deuterium), a substituted or unsubstituted branched or linear alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 22 carbon atoms, or a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms; R １１ ~R ２０ At least one of the groups represents a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms. In claim 1, The light-emitting device, wherein the first organic compound and the second organic compound are each independently an organic compound represented by the following general formula (G1): (However, in general formula (G1), R １ ~R １０ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted branched or linear alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 22 carbon atoms, and the first organic compound and the second organic compound are different organic compounds. In claim 1, the first organic compound is an organic compound represented by the following general formula (G1): The light-emitting device, wherein the second organic compound is an organic compound represented by the following general formula (G2): (In general formula (G1), R １ ~R １０ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted branched or linear alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 22 carbon atoms. (In general formula (G2), R １１ ~R ２０ each independently represents hydrogen (including deuterium), a substituted or unsubstituted branched or linear alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 22 carbon atoms, or a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms; R １１ ~R ２０ At least one of the groups represents a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms. In any one of claims 1 to 12, The light-emitting device, wherein the third organic compound is an organic compound represented by the following general formula (G3): (In the general formula (G3), Ar １ , Ar ３ and Ar ５ represents a substituted or unsubstituted arylene group having 6 to 22 carbon atoms or a substituted or unsubstituted heteroarylene group having 1 to 30 carbon atoms; Ar ２ and Ar ４ represents any one of a substituted or unsubstituted aryl group having 6 to 22 carbon atoms and a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms; n, m, and l represent an integer of 0 to 3; when n, m, and l are 2 or more, a plurality of Ar １ or Ar ３ or Ar ５ may be the same or different, and Ar ６ is represented by any one of the following general formulas (g3-1) to (g3-4): In the general formulas (g3-1) to (g3-4), X represents an oxygen atom, a sulfur atom, or a nitrogen atom. When X is a nitrogen atom, the nitrogen atom has one of a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, a linear or branched alkyl group having 1 to 6 carbon atoms, and a cycloalkyl group having 3 to 10 carbon atoms. In addition, R ２１ ~R ２８ , and R ３０ ~R ３５ and R ４０ ~R ４５ and R ５０ ~R ５５ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted branched or linear alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 22 carbon atoms, and a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms; R ２１ ~R ２８ One of the following, or R ３０ ~R ３５ One of the following, or R ４０ ~R ４５ One of the following, or R ５０ ~R ５５ One of them is Ar in general formula (G3). ５ or a bond to nitrogen.)

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