Light emitting device

Abstract

Provided is a light-emitting device having high luminous efficiency. Provided is a light emitting device including a first electrode, a second electrode, a light emitting layer, a first hole transport layer, and a first electron transport layer, the first electrode being formed on a substrate and located between the second electrode and the substrate, the light emitting layer, the first hole transport layer, and the first electron transport layer being located between the first electrode and the second electrode, the light-emitting layer is located between the first hole transport layer and the first electron transport layer, the light-emitting layer and the first hole transport layer are in contact with each other, and the GSPslope (mV / nm) of a layer located on the second electrode side of the light-emitting layer and the first hole transport layer is smaller than the GSPslope (mV / nm) of a layer located on the first electrode side. Note that GSPslope (mV / nm) is represented by [Delta] V / [Delta] d, and [Delta] V (mV) is the amount of change in the surface potential with respect to the amount of change in the thickness [Delta] d (nm).

Description

Technical Field

[0001] One aspect of the present invention relates to an organic compound, an organic semiconductor element, a light-emitting element, an organic EL element, a photodiode, a display module, a lighting module, a display device, a light-emitting device, an electronic device, a lighting device, and an electronic device. Note that this aspect of the present invention is not limited to the above-described technical fields. The technical field of one aspect of the invention disclosed in this specification relates to an object, method, or manufacturing method. Furthermore, one aspect of the present invention relates to a process, machine, manufacture, or composition of matter. Therefore, more specifically, examples of the technical field of one aspect of the present invention disclosed in this specification include semiconductor devices, display devices, liquid crystal display devices, light-emitting devices, lighting devices, energy storage devices, storage devices, imaging devices, methods for driving these devices, or methods for manufacturing these devices. Background Technology

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

[0003] Because this type of organic EL element is a self-emissive element, it offers advantages over liquid crystal displays (LCDs) in terms of higher visibility and the elimination of the need for a backlight when used as pixels in a display, making it particularly suitable for flat panel displays. Furthermore, displays using this type of EL element can be manufactured to be thin and lightweight, which is a significant advantage. Moreover, its extremely fast response time is also a characteristic of this organic EL element.

[0004] Furthermore, because the light-emitting layer of this organic EL element can be formed continuously in a planar shape, surface emission can be achieved. Since this is a feature that is difficult to obtain in point light sources such as incandescent lamps and LEDs, or linear light sources such as fluorescent lamps, the light-emitting layer of the aforementioned organic EL element is also highly valuable as a surface light source that can be used for lighting and the like.

[0005] As mentioned above, displays or lighting devices using organic EL elements can be adapted for a wide variety of electronic devices, and research and development of organic EL elements with better characteristics are becoming increasingly active (see, for example, non-patent literature 1).

[0006] [Non-Patent Literature 1] Hiroshi Noguchi and 2 others, “Orientation polarization phenomenon of polar molecules and interfacial characteristics of organic thin film devices”, Journal of the Vacuum Society of Japan, 2015, Vol.58, No.3. Summary of the Invention

[0007] One objective of this invention is to provide a light-emitting device with high luminous efficiency. Another objective of this invention is to provide a light-emitting device with low driving voltage. Furthermore, another objective of this invention is to provide any one of a light-emitting device, an electronic device, and a display device with low power consumption.

[0008] Note that the description of these objectives does not preclude the existence of other objectives. Note that one embodiment of the invention does not necessarily require achieving all of the above objectives. Note that objectives other than those described above can be understood and extracted from the description, drawings, claims, etc.

[0009] One aspect of the present invention is a light-emitting device, wherein, by selecting organic compounds for each layer of the organic compound layer such that the GSP_slope (mV / nm) of the light-emitting layer is less than the GSP_slope (mV / nm) of at least one of the carrier transport layers sandwiching the light-emitting layer in the organic compound layer of a positive light-emitting device, and the GSP_slope (mV / nm) of the light-emitting layer is greater than the GSP_slope (mV / nm) of at least one of the carrier transport layers sandwiching the light-emitting layer in the organic compound layer of an inverted light-emitting device, excitons generated in the light-emitting layer can emit light efficiently, and GSP_slope (mV / nm) represents the magnitude of the giant surface potential (GSP) of the light-emitting layer.

[0010] One aspect of the present invention is a light-emitting device comprising a first electrode, a second electrode, a light-emitting layer, a first hole transport layer, and a first electron transport layer. The light-emitting layer, the first hole transport layer, and the first electron transport layer are located between the first electrode and the second electrode. The light-emitting layer is located between the first hole transport layer and the first electron transport layer, and the light-emitting layer and the first hole transport layer are in contact with each other. The gas permeable surface area (GSP) of the layer located on the second electrode side of the light-emitting layer and the first hole transport layer is smaller than that of the layer located on the first electrode side. Note that the first electrode is formed on a substrate and located between the second electrode and the substrate. Furthermore, the first electrode is electrically connected to a transistor. Additionally, a portion of the first electrode is covered by an insulator. Furthermore, the first electrode is formed on an insulating film and located between the second electrode and the insulating film, and an external connection electrode is disposed on the insulating film.

[0011] One aspect of the present invention is a light-emitting device comprising a first electrode, a second electrode, a light-emitting layer, a first hole transport layer, and a first electron transport layer. The light-emitting layer, the first hole transport layer, and the first electron transport layer are located between the first electrode and the second electrode. The light-emitting layer is located between the first hole transport layer and the first electron transport layer. The gas permeable surface area (GSP) of the layer located on the first electrode side of the light-emitting layer and the first electron transport layer is smaller than that of the layer located on the second electrode side. Note that the first electrode is formed on a substrate and located between the second electrode and the substrate. Furthermore, the first electrode is electrically connected to a transistor. Additionally, a portion of the first electrode is covered by an insulator. Furthermore, the first electrode is formed on an insulating film and located between the second electrode and the insulating film, and an external connection electrode is disposed on the insulating film.

[0012] One aspect of the present invention is a light-emitting device having the above-described structure, wherein the GSP_slope (mV / nm) of the layer located on the second electrode side of the light-emitting layer and the first hole transport layer is smaller than the GSP_slope (mV / nm) of the layer located on the first electrode side.

[0013] One aspect of the present invention is a light-emitting device having the above-described structure, the light-emitting device further comprising a second hole transport layer and a second electron transport layer, the second hole transport layer and the second electron transport layer being located between a first electrode and a second electrode, a first hole transport layer being located between the second hole transport layer and a light-emitting layer, a first electron transport layer being located between the second electron transport layer and a light-emitting layer, wherein the GSP_slope (mV / nm) of the layer located on the second electrode side of the first hole transport layer and the second hole transport layer is larger than the GSP_slope (mV / nm) of the layer located on the first electrode side of the first electron transport layer and the second electron transport layer is larger than the GSP_slope (mV / nm) of the layer located on the second electrode side of the first electron transport layer and the second electron transport layer.

[0014] One aspect of the present invention is a light-emitting device having the above-described structure, wherein the difference between the GSP_slope (mV / nm) of the light-emitting layer and the GSP_slope (mV / nm) of the first hole transport layer is greater than or equal to 0 mV / nm and less than or equal to 20 mV / nm.

[0015] One aspect of the present invention is a light-emitting device having the above-described structure, wherein the difference between the GSP_slope (mV / nm) of the light-emitting layer and the GSP_slope (mV / nm) of the first electron transport layer is greater than or equal to 0 mV / nm and less than or equal to 20 mV / nm.

[0016] One aspect of the present invention is a light-emitting device having the above-described structure, wherein the difference between the GSP_slope (mV / nm) of the first hole transport layer and the GSP_slope (mV / nm) of the first electron transport layer is greater than or equal to 0 mV / nm and less than or equal to 20 mV / nm.

[0017] One aspect of the present invention is a light-emitting device having the above-described structure, wherein at least one of the first hole transport layer and the first electron transport layer has a refractive index of 1.75 or less at the peak wavelength of the electroluminescence spectrum of the light-emitting device.

[0018] One aspect of the present invention is a light-emitting device having the above-described structure, wherein at least one of the second hole transport layer and the second electron transport layer has a refractive index of 1.75 or less at the peak wavelength of the electroluminescence spectrum of the light-emitting device.

[0019] One aspect of the present invention is a light-emitting device comprising a first electrode, a second electrode, a light-emitting layer, a first hole transport layer, and a first electron transport layer. The light-emitting layer, the first hole transport layer, and the first electron transport layer are located between the first electrode and the second electrode. The first hole transport layer is located between the first electrode and the light-emitting layer, and the first electron transport layer is located between the second electrode and the light-emitting layer. The light-emitting layer and the first hole transport layer are in contact with each other. The light-emitting layer comprises a host material and a light-emitting substance. The first hole transport layer comprises a first organic compound, and the first electron transport layer comprises a second organic compound. The gas-slope (GSP) of the vapor-deposited film of the host material is smaller than the GSP of the vapor-deposited film of the first organic compound (mV / nm). Note that the first electrode is formed on a substrate and located between the second electrode and the substrate. Furthermore, the first electrode is electrically connected to a transistor. Additionally, a portion of the first electrode is covered by an insulator. Furthermore, the first electrode is formed on an insulating film and located between the second electrode and the insulating film, and an external connection electrode is disposed on the insulating film.

[0020] One aspect of the present invention is a light-emitting device comprising a first electrode, a second electrode, a light-emitting layer, a first hole transport layer, and a first electron transport layer. The light-emitting layer, the first hole transport layer, and the first electron transport layer are located between the first electrode and the second electrode. The first hole transport layer is located between the first electrode and the light-emitting layer, and the first electron transport layer is located between the second electrode and the light-emitting layer. The light-emitting layer comprises a host material and a light-emitting substance. The first hole transport layer comprises a first organic compound, and the first electron transport layer comprises a second organic compound. The gas-shielded surface area (GSP) of the vapor-deposited film of the host material is smaller than that of the vapor-deposited film of the second organic compound (mV / nm). Note that the first electrode is formed on a substrate and located between the second electrode and the substrate. Furthermore, the first electrode is electrically connected to a transistor. Additionally, a portion of the first electrode is covered by an insulator. Furthermore, the first electrode is formed on an insulating film and located between the second electrode and the insulating film, and an external connection electrode is disposed on the insulating film.

[0021] One aspect of the present invention is a light-emitting device having the above-described structure, wherein the GSP_slope (mV / nm) of the vapor-deposited film of the host material is smaller than the GSP_slope (mV / nm) of the vapor-deposited film of the first organic compound.

[0022] One aspect of the present invention is a light-emitting device having the above-described structure, the light-emitting device further comprising a second hole transport layer and a second electron transport layer, the second hole transport layer and the second electron transport layer being located between a first electrode and a second electrode, the first hole transport layer being located between the second hole transport layer and the light-emitting layer, the first electron transport layer being located between the second electron transport layer and the light-emitting layer, the second hole transport layer comprising a third organic compound, the second electron transport layer comprising a fourth organic compound, the GSP_slope (mV / nm) of the vapor-deposited film of the first organic compound being larger than the GSP_slope (mV / nm) of the vapor-deposited film of the third organic compound, and the GSP_slope (mV / nm) of the vapor-deposited film of the second organic compound being larger than the GSP_slope (mV / nm) of the vapor-deposited film of the fourth organic compound.

[0023] One aspect of the present invention is a light-emitting device having the above-described structure, wherein the difference between the GSP_slope (mV / nm) of the vapor-deposited film of the host material and the GSP_slope (mV / nm) of the vapor-deposited film of the first organic compound is 0 mV / nm or more and 20 mV / nm or less.

[0024] One aspect of the present invention is a light-emitting device having the above-described structure, wherein the difference between the GSP_slope (mV / nm) of the vapor-deposited film of the host material and the GSP_slope (mV / nm) of the vapor-deposited film of the second organic compound is greater than or equal to 0 mV / nm and less than or equal to 20 mV / nm.

[0025] One aspect of the present invention is a light-emitting device having the above-described structure, wherein the difference between the GSP_slope (mV / nm) of the vapor-deposited film of the first organic compound and the GSP_slope (mV / nm) of the vapor-deposited film of the second organic compound is greater than or equal to 0 mV / nm and less than or equal to 20 mV / nm.

[0026] One aspect of the present invention is a light-emitting device having the above-described structure, wherein at least one of the refractive index of the first organic compound film and the refractive index of the second organic compound film is 1.75 or less at the peak wavelength of the electroluminescence spectrum of the light-emitting device.

[0027] One aspect of the present invention is a light-emitting device having the above-described structure, wherein at least one of the first organic compound and the second organic compound is an organic compound having at least one group selected from alkyl groups having 2 to 10 carbon atoms and cycloalkyl groups having 6 to 12 carbon atoms.

[0028] One aspect of the present invention is a light-emitting device having the above-described structure, wherein the refractive index of the film of the third organic compound is 1.75 or less at the peak wavelength of the electroluminescence spectrum of the light-emitting device.

[0029] One aspect of the present invention is a light-emitting device having the above-described structure, wherein at least one of the third and fourth organic compounds is an organic compound having at least one group selected from alkyl groups having 2 to 10 carbon atoms and cycloalkyl groups having 6 to 12 carbon atoms.

[0030] One aspect of the present invention is a light-emitting device having the above-described structure, wherein the light-emitting material is a fluorescent light-emitting material.

[0031] One aspect of the present invention is a light-emitting device having the above-described structure, wherein the energy difference between the HOMO energy level of the host material and the HOMO energy level of the luminescent material is 0.25 eV or more, and the concentration of the luminescent material in the light-emitting layer of the host material is 0.5 wt% or more and 25 wt% or less.

[0032] Note that in one embodiment of the invention, GSP_slope(mV / nm) is expressed as ΔV / Δd, where ΔV(mV) is the change in surface potential with respect to a change in thickness Δd(nm).

[0033] According to one aspect of the present invention, a light-emitting device with high luminous efficiency can be provided. According to one aspect of the present invention, a light-emitting device with low driving voltage can be provided. Furthermore, according to one aspect of the present invention, any one of a light-emitting device, an electronic device, and a display device with low power consumption can be provided.

[0034] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the invention does not necessarily require all of the above-described effects. Note that effects other than those described above can be understood and extracted from the description, drawings, claims, etc. Attached Figure Description

[0035] Figure 1A and Figure 1B This is a diagram illustrating the structure of the light-emitting device according to the embodiment; Figure 2A and Figure 2B This is a diagram illustrating the structure of the light-emitting device according to the embodiment; Figure 3A and Figure 3B This is a diagram illustrating the structure of the light-emitting device according to the embodiment; Figure 4A and Figure 4B This is a diagram illustrating the structure of the light-emitting device according to the embodiment; Figures 5A to 5D This is a diagram illustrating the structure of the light-emitting device according to the embodiment; Figures 6A to 6E This is a diagram illustrating the structure of the light-emitting device according to the embodiment; Figure 7A and Figure 7B These are the top view and cross-sectional view of the light-emitting device; Figures 8A to 8G This is a top view showing an example of the structure of a pixel; Figures 9A to 9I This is a top view showing an example of the structure of a pixel; Figure 10A and Figure 10B This is a perspective view showing an example of the structure of a display module; Figure 11A and Figure 11B This is a cross-sectional view showing an example of the structure of a light-emitting device; Figure 12 This is a perspective view showing an example of the structure of a light-emitting device; Figure 13A This is a cross-sectional view showing an example of the structure of a light-emitting device. Figure 13B and Figure 13C This is a cross-sectional view showing an example of a transistor structure; Figure 14 This is a cross-sectional view showing an example of the structure of a light-emitting device; Figures 15A to 15C These are cross-sectional and top views illustrating an example of the structure of a light-emitting device; Figures 16A to 16D This is a cross-sectional view showing an example of the structure of a light-emitting device; Figures 17A to 17CThese are cross-sectional and top views illustrating an example of the structure of a light-emitting device; Figures 18A to 18D This is a diagram illustrating an example of an electronic device; Figures 19A to 19F This is a diagram illustrating an example of an electronic device; Figures 20A to 20G This is a diagram illustrating an example of an electronic device; Figure 21A and Figure 21B This is a diagram showing an active matrix type light-emitting device; Figure 22A and Figure 22B This is a diagram showing an active matrix type light-emitting device; Figure 23 This is a diagram showing an active matrix type light-emitting device; Figure 24A and Figure 24B This is a diagram showing a passive matrix-type light-emitting device; Figure 25A and Figure 25B This is a diagram illustrating an electronic device according to an embodiment; Figure 26 This is a diagram illustrating an electronic device according to an embodiment; Figure 27 This is a diagram showing the structure of the device according to an embodiment; Figure 28 This is a graph showing the capacitance-voltage characteristics of measuring device 1; Figure 29 This is a graph showing the current density-voltage characteristics of measuring device 1; Figure 30 It is a diagram showing the luminance-current density characteristics of light-emitting device 1, light-emitting device 2, and comparative light-emitting devices 4 to 6; Figure 31 It is a diagram showing the brightness-voltage characteristics of light-emitting device 1, light-emitting device 2, and comparison light-emitting devices 4 to 6; Figure 32 It is a diagram showing the current efficiency-luminance characteristics of light-emitting device 1, light-emitting device 2, and comparative light-emitting devices 4 to 6; Figure 33 It is a graph showing the current density-voltage characteristics of light-emitting device 1, light-emitting device 2, and comparison light-emitting devices 4 to 6; Figure 34 It is a diagram showing the power efficiency-luminance characteristics of light-emitting device 1, light-emitting device 2, and comparative light-emitting devices 4 to 6; Figure 35 This is a diagram showing the external quantum efficiency-luminance characteristics of light-emitting device 1, light-emitting device 2, and comparative light-emitting devices 4 to 6; Figure 36 It is a diagram showing the blue index-brightness characteristics of light-emitting device 1, light-emitting device 2, and comparative light-emitting devices 4 to 6; Figure 37 It is a diagram showing the electroluminescence spectra of light-emitting device 1, light-emitting device 2, and comparative light-emitting devices 4 to 6; Figure 38 This is a diagram showing the luminance-current density characteristics of light-emitting device 3 and comparative light-emitting devices 7 to 9; Figure 39 This is a diagram showing the brightness-voltage characteristics of light-emitting device 3 and comparative light-emitting devices 7 to 9; Figure 40 This is a diagram showing the current efficiency-luminance characteristics of light-emitting device 3 and comparative light-emitting devices 7 to 9; Figure 41 This is a graph showing the current density-voltage characteristics of light-emitting device 3 and comparison light-emitting devices 7 to 9; Figure 42 This is a diagram showing the power efficiency-luminance characteristics of light-emitting device 3 and comparative light-emitting devices 7 to 9; Figure 43 This is a diagram showing the external quantum efficiency-luminance characteristics of light-emitting device 3 and comparative light-emitting devices 7 to 9; Figure 44 This is a diagram showing the blue index-brightness characteristics of light-emitting device 3 and comparative light-emitting devices 7 to 9; Figure 45 This is a diagram showing the electroluminescence spectra of light-emitting device 3 and comparative light-emitting devices 7 to 9; Figure 46A and Figure 46B This is a graph showing the emission spectrum of 3,10PCA2Nbf(IV)-02; Figure 47 This is a diagram showing the emission spectrum of Bnf(II)PhA-02-d5; Figure 48A and Figure 48B This is a graph showing the emission spectrum of Bnf(II)PhA-02-d5 (with the addition of a triplet sensitizer); Figure 49 This is a diagram showing the fluorescence lifetime of light-emitting device 1, light-emitting device 2, light-emitting device 3, and comparative light-emitting device 5; Figure 50 It is a diagram showing the luminance-current density characteristics of light-emitting devices 10 to 13, comparison light-emitting device 14, and comparison light-emitting device 15; Figure 51It is a diagram showing the brightness-voltage characteristics of light-emitting devices 10 to 13, comparison light-emitting device 14, and comparison light-emitting device 15; Figure 52 It is a graph showing the current efficiency-brightness characteristics of light-emitting devices 10 to 13, comparison light-emitting device 14, and comparison light-emitting device 15; Figure 53 It is a graph showing the current density-voltage characteristics of light-emitting devices 10 to 13, comparison light-emitting device 14, and comparison light-emitting device 15; Figure 54 It is a diagram showing the power efficiency-luminance characteristics of light-emitting devices 10 to 13, comparison light-emitting device 14, and comparison light-emitting device 15; Figure 55 It is a diagram showing the external quantum efficiency-luminance characteristics of light-emitting devices 10 to 13, comparison light-emitting device 14, and comparison light-emitting device 15; Figure 56 It is a diagram showing the blue index-brightness characteristics of light-emitting devices 10 to 13, comparative light-emitting device 14, and comparative light-emitting device 15; Figure 57 It is a diagram showing the electroluminescence spectra of light-emitting devices 10 to 13, comparison light-emitting device 14, and comparison light-emitting device 15; Figure 58 This is a diagram showing the emission spectrum of 2αN-αNPhA; Figure 59A and Figure 59B This is a graph showing the emission spectrum of 2αN-αNPhA (with the addition of a triplet sensitizer); Figure 60 This is a graph showing the fluorescence lifetime of light-emitting device 10 and comparative light-emitting device 15. Detailed Implementation

[0036] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the contents described below, and its methods and details can be varied in various forms without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited only to the contents described in the embodiments shown below.

[0037] Furthermore, for ease of understanding, the positions, sizes, and extents of various structures shown in the accompanying drawings, etc., do not necessarily represent their actual positions, sizes, and extents. Therefore, the disclosed invention is not necessarily limited to the positions, sizes, and extents disclosed in the accompanying drawings, etc.

[0038] In this specification, ordinal numbers such as "first" and "second" are used for convenience, but they do not limit the number of constituent elements or their order. The order of constituent elements may include, for example, a process sequence or a stacking sequence. That is, the ordinal numbers used in the embodiments of this specification may differ from those used in the claims. Furthermore, the ordinal numbers used in the embodiments of this specification may differ from those used in the claims.

[0039] Furthermore, in this specification and the like, when the structure of the invention is described using the accompanying drawings, the same symbol is sometimes used in different drawings to show the same parts.

[0040] Furthermore, in this specification and other materials, the terms "film" and "layer" may be interchanged. For example, "conductive layer" may sometimes be replaced with "conductive film." Or, for example, "insulating film" may sometimes be replaced with "insulating layer."

[0041] Note that in this specification, photoluminescence (PL) spectroscopy refers to the spectrum obtained by fixing the excitation wavelength of the excitation light and scanning the wavelength of the emitted light in fluorescence spectrophotometry. It is sometimes also called emission spectrum. Furthermore, emission spectra sometimes include fluorescent and phosphorescent components. In this specification, emission spectra consisting of fluorescent components are sometimes specifically referred to as fluorescence spectra, and emission spectra consisting of phosphorescent components are sometimes specifically referred to as phosphorescence spectra.

[0042] Implementation Method 1 In this embodiment, refer to Figures 1A to 5D The present invention describes a light-emitting device 10A of one embodiment of the present invention and a light-emitting device 10B of another embodiment of the present invention.

[0043] like Figures 1A to 4B As shown, both light-emitting devices 10A and 10B are located on the substrate 1000. Both light-emitting devices 10A and 10B include a first electrode 101, a second electrode 102, and an organic compound layer 103 located between the first electrode 101 and the second electrode 102. Additionally, as... Figures 1A to 4B As shown, the organic compound layer 103 includes at least a light-emitting layer 113, a hole transport layer 112, and an electron transport layer 114. The hole transport layer 112 functions to transport holes injected into the organic compound layer 103 from one of the first electrode 101 and the second electrode 102 to the light-emitting layer 113. The electron transport layer 114 functions to transport electrons injected into the organic compound layer 103 from the other of the first electrode 101 and the second electrode 102 to the light-emitting layer 113.

[0044] In addition, such as Figures 1A to 4B As shown, in light-emitting devices 10A and 10B, a first electrode 101 is formed on a substrate 1000. Alternatively, the first electrode 101 can be described as being disposed between the second electrode 102 and the substrate 1000. That is, the first electrode 101 is the electrode that is disposed before the second electrode 102. Furthermore, when a transistor is disposed on the substrate 1000, the first electrode 101 is electrically connected to the transistor via wiring. Alternatively, the first electrode 101 can be disposed on an insulating layer on which an external connection electrode is disposed, which is used as a terminal for disposing of an FPC (flexible printed circuit) or similar device. Additionally, a portion of the first electrode 101 may be covered by an insulator on the substrate 1000 or the insulating layer on which the first electrode 101 is disposed.

[0045] exist Figure 1A , Figure 2A , Figure 3A , Figure 4A The light-emitting device 10A shown is Figure 1B , Figure 2B , Figure 3B , Figure 4B In the light-emitting device 10B shown, the first electrode 101 and the second electrode 102 have different functions. In the light-emitting device 10A, the first electrode 101 is used as the anode, and the second electrode 102 is used as the cathode. In this specification, light-emitting devices such as the light-emitting device 10A, where the first electrode is disposed on one side of the substrate and is used as the anode, are sometimes referred to as upright light-emitting devices. On the other hand, in the light-emitting device 10B, the first electrode 101 is used as the cathode, and the second electrode 102 is used as the anode. In this specification, light-emitting devices such as the light-emitting device 10B, where the first electrode is disposed on one side of the substrate and is used as the cathode, are sometimes referred to as inverted light-emitting devices.

[0046] Holes injected from the first electrode 101 (serving as the anode) into the organic compound layer 103 and transported by the hole transport layer 112 recombine with electrons injected from the second electrode 102 (serving as the cathode) into the organic compound layer 103 and transported by the electron transport layer 114 in the light-emitting layer 113, thereby causing the upright light-emitting device 10A to emit light. Therefore, it is preferable that in the light-emitting device 10A, the hole transport layer 112 is located between the first electrode 101 and the light-emitting layer 113, and the electron transport layer 114 is located between the second electrode 102 and the light-emitting layer 113.

[0047] The inverted light-emitting device 10B emits light by recombination in the light-emitting layer 113 between electrons transported by the electron transport layer 114 from the first electrode 101 (serving as the cathode) and holes transported by the hole transport layer 112 from the second electrode 102 (serving as the anode) and the organic compound layer 103. Therefore, it is preferable that in the light-emitting device 10B, the hole transport layer 112 is located between the second electrode 102 and the light-emitting layer 113, and the electron transport layer 114 is located between the first electrode 101 and the light-emitting layer 113.

[0048] In light-emitting devices 10A and 10B, the hole transport layer 112 and the electron transport layer 114 can be either single layers or multiple layers stacked together (hereinafter also referred to as stacked structures). Figure 4A The light-emitting device 10A shown is Figure 4B The organic compound layer 103 of the light-emitting device 10B shown includes at least a light-emitting layer 113, a first hole transport layer 112_1, a second hole transport layer 1122, a first electron transport layer 114_1, and a second electron transport layer 1142. Figure 4A In the organic compound layer 103 of the light-emitting device 10A shown, a first hole transport layer 112_1 is located between the first electrode 101 and the light-emitting layer 113, a second hole transport layer 112_2 is located between the first hole transport layer 112_1 and the first electrode 101, a first electron transport layer 114_1 is located between the second electrode 102 and the light-emitting layer 113, and a second electron transport layer 114_2 is located between the first electron transport layer 114_1 and the second electrode 102. Additionally, in Figure 4B In the organic compound layer 103 of the light-emitting device 10B shown, the first electron transport layer 114_1 is located between the first electrode 101 and the light-emitting layer 113, the second electron transport layer 114_2 is located between the first electron transport layer 114_1 and the first electrode 101, the first hole transport layer 112_1 is located between the second electrode 102 and the light-emitting layer 113, and the second hole transport layer 112_2 is located between the first hole transport layer 112_1 and the second electrode 102. Note that the first hole transport layer 112_1 and the second hole transport layer 112_2 are sometimes collectively referred to as hole transport layer 112, and the first electron transport layer 114_1 and the second electron transport layer 114_2 are collectively referred to as electron transport layer 114.

[0049] Furthermore, more preferably, the light-emitting device 10A and the light-emitting device 10B include a hole injection layer 111 between the anode and the hole transport layer 112, and an electron injection layer 115 between the cathode and the electron transport layer 114. Figure 1A , Figure 2A and Figure 3AThe upright light-emitting device 10A shown has a structure in which a hole injection layer 111, a hole transport layer 112, a light-emitting layer 113, an electron transport layer 114, an electron injection layer 115, and a second electrode 102 serving as a cathode are sequentially stacked on a first electrode 101 serving as an anode. Furthermore, Figure 4A The upright light-emitting device 10A shown has a structure on which a hole injection layer 111, a second hole transport layer 112_2, a first hole transport layer 112_1, a light-emitting layer 113, a first electron transport layer 114_1, a second electron transport layer 114_2, an electron injection layer 115, and a second electrode 102 serving as a cathode are sequentially stacked on a first electrode 101 serving as an anode. Furthermore, Figure 1B , Figure 2B and Figure 3B The inverted light-emitting device 10B shown has a structure in which an electron injection layer 115, an electron transport layer 114, a light-emitting layer 113, a hole transport layer 112, a hole injection layer 111, and a second electrode 102 serving as an anode are sequentially stacked on a first electrode 101 serving as a cathode. Furthermore, Figure 4B The inverted light-emitting device 10B shown has a structure on which an electron injection layer 115, a second electron transport layer 114_2, a first electron transport layer 114_1, a light-emitting layer 113, a first hole transport layer 112_1, a second hole transport layer 112_2, a hole injection layer 111 and a second electrode 102 serving as an anode are stacked sequentially on a first electrode 101 serving as a cathode.

[0050] Note that the structures of light-emitting devices 10A and 10B are not limited to... Figures 1A to 4B The structure shown is an example. For instance, it may also have a structure where one of the hole transport layer and the electron transport layer is a single layer and the other is a two-layer structure. Furthermore, it may have a structure where one or both of the hole transport layer and the electron transport layer are three or more layers. Additionally, it may have a structure including functional layers that can lower the injection barrier for holes or electrons, improve the transport of holes or electrons, impede the transport of holes or electrons, or suppress quenching phenomena caused by electrodes.

[0051] The inventors have discovered that by selecting the material for each layer in light-emitting device 10A and light-emitting device 10B, taking into account the GSP_slope of the light-emitting layer 113 and the layers surrounding the light-emitting layer 113, the luminous efficiency of light-emitting device 10A and light-emitting device 10B can be improved.

[0052] GSP is a phenomenon caused by spontaneous polarization (SOP) resulting from the concentration of the permanent electric dipole moment of the vapor-deposited film along the thickness direction.

[0053] The surface potential of vapor-deposited films exhibiting GSP changes proportionally in an unsaturated manner with increasing thickness. For example, the surface potential of a vapor-deposited film of tris(8-hydroxyquinoline) aluminum (Alq3) reaches approximately 28V at a thickness of 560nm. Its electric field strength reaches 5×10⁻⁶. 5 V / cm, which is roughly equivalent to the electric field strength when a typical light-emitting device is driven.

[0054] GSP slope is expressed as ΔV / Δd, where ΔV (mV) is the change in surface potential in a film where the GSP slope varies proportionally to the thickness, with respect to a change in thickness Δd (nm). Furthermore, GSP slope is positive when the surface potential increases with increasing thickness, and negative when the surface potential decreases with increasing thickness. Alq3 described above can be considered a material with a positive GSP slope. Additionally, in layers with a positive GSP slope, the potential on the substrate side is low, and in layers with a negative GSP slope, the potential on the substrate side is high.

[0055] As described above, the GSP (Gas Plasma Spread) is a phenomenon caused by the SOP (Site Optimization Point) resulting from the concentration of the permanent electric dipole moment along the thickness direction. That is, in layers with a positive GSP slope, negative polarization charges can be considered to be generated on the side of the deposition start surface (substrate side) and positive polarization charges on the side of the deposition end surface (second electrode side). Similarly, in layers with a negative GSP slope, positive polarization charges can be considered to be generated on the side of the deposition start surface (substrate side) and negative polarization charges on the side of the deposition end surface (second electrode side). This generation of polarization charges is the source of the GSP.

[0056] In many cases, the vapor-deposited film of organic compounds has a positive GSP_slope. For example, when the second layer is deposited in contact with the first layer, the GSP_slope of the first and second layers has the same positive sign. This means that negative polarization charges are generated on the starting side of each layer's deposition and positive polarization charges are generated on the ending side. In this case, the negative polarization charge on the first layer side of the second layer cancels out the positive polarization charge on the second layer side of the first layer. Therefore, the remaining charge can be considered only as the interface charge (fixed charge) at the interface between the first and second layers. Note that in this specification, the virtual charge that can be considered as interface charge is sometimes referred to as interface charge.

[0057] This virtual interface charge can sometimes lead to a decrease in the luminous efficiency of the light-emitting device. For example, when there is an excessive amount of negative interface charge at the interface between the hole transport layer 112 and the light-emitting layer 113 in the light-emitting device, the excessive number of holes attracted to the interface from the anode side can cause exciton annihilation due to the interaction between excitons and polarons, which can sometimes reduce the luminous efficiency of the light-emitting device.

[0058] The aforementioned decrease in luminous efficiency occurs significantly in the following light-emitting device: This device adds a hole-trapping fluorescent material to the host material in the luminescent layer 113 and utilizes triplet-triplet annihilation (TTA) caused by multiple triplet excitons to improve luminous efficiency. This is because, in this structure, excitons are particularly localized on the hole transport layer 112 side of the luminescent layer 113. Therefore, excessive holes attracted from the anode side to the interface between the hole transport layer 112 and the luminescent layer 113 are easily interacted with these excitons, resulting in interactions between excitons and polarons.

[0059] In one aspect of the present invention, by controlling the polarization charge and the interface charge, which can be considered as being generated in the stacked film originating from the polarization charge, the efficiency degradation of the light-emitting device due to the interface charge can be suppressed, thereby achieving high efficiency of the light-emitting device. Note that in Figures 1A to 4B In the middle, with σ + and σ - This refers to spontaneous polarization that occurs due to the orientation of the permanent electric dipole moments of the layers deposited by vapor deposition being concentrated along the thickness direction. + Indicates positive polarization, σ - This indicates negative polarization. Additionally, σ near the interfaces of each layer... + or σ - The more elements there are, the greater the spontaneous polarization.

[0060] For example, in one embodiment of the light-emitting device of the present invention, the GSP_slope of the layer located on the side of the second electrode 102 in the light-emitting layer 113 and the hole transport layer 112 is preferably smaller than the GSP_slope of the layer located on the side of the first electrode 101 (structural example 1). Figure 1A This illustrates a positively positioned light-emitting device 10A using structure example 1. Figure 1B The inverted light-emitting device 10B using structural example 1 is shown.

[0061] exist Figure 1AIn the upright light-emitting device 10A shown, the layer located on the side of the second electrode 102 in the light-emitting layer 113 and the hole transport layer 112 refers to the light-emitting layer 113, and the layer located on the side of the first electrode 101 in the light-emitting layer 113 and the hole transport layer 112 refers to the hole transport layer 112. That is, when the upright light-emitting device 10A adopts structure example 1, the GSP_slope of the light-emitting layer 113 is preferably smaller than the GSP_slope of the hole transport layer 112.

[0062] exist Figure 1B In the inverted light-emitting device 10B shown, the layer located on the side of the second electrode 102 in the light-emitting layer 113 and the hole transport layer 112 refers to the hole transport layer 112, and the layer located on the side of the first electrode 101 in the light-emitting layer 113 and the hole transport layer 112 refers to the light-emitting layer 113. That is, when the inverted light-emitting device 10B adopts structure example 1, the GSP_slope of the hole transport layer 112 is preferably smaller than the GSP_slope of the light-emitting layer 113.

[0063] When the upright light-emitting device 10A and the inverted light-emitting device 10B adopt the structure example 1, such as Figure 1A and Figure 1B As shown, the polarization charge on the light-emitting layer 113 side of the hole transport layer 112 cancels out the polarization charge on the hole transport layer 112 side of the light-emitting layer 113. Therefore, it can be considered that a positive interface charge 50a remains at the interface between the hole transport layer 112 and the light-emitting layer 113. Consequently, hole injection into the hole transport layer 112 from the anode side is suppressed, preventing hole accumulation at the interface. As a result, exciton annihilation caused by the interaction between excitons and polarons can also be prevented, thereby improving the luminous efficiency of the light-emitting device. In particular, when structure example 1 is used in a light-emitting device where a fluorescent material is used in the light-emitting layer 113 as the light-emitting device and TTA is used to improve luminous efficiency, the effect of improving luminous efficiency is high, and therefore it is preferred.

[0064] Furthermore, when the difference between the GSP_slope of the light-emitting layer 113 and the GSP_slope of the hole transport layer 112 is too large in structural example 1, it can be considered that the positive interface charge 50a remaining at the interface between the hole transport layer 112 and the light-emitting layer 113 is too large. Therefore, electrons are attracted and accumulate at the interface, which sometimes blocks the recombination of charge carriers in the light-emitting layer 113, leading to a decrease in luminous efficiency. Therefore, the difference between the GSP_slope of the light-emitting layer 113 and the GSP_slope of the hole transport layer 112 is preferably 0 mV / nm or more and 20 mV / nm or less. By having this GSP_slope relationship, the luminous efficiency of the light-emitting device can be further improved.

[0065] Furthermore, as described above, in structural example 1, controlling the interface charge, which can be considered as generated at the interface between the light-emitting layer 113 and the layer in contact with the light-emitting layer 113, is important. Therefore, it is more preferable that the hole transport layer 112 is in contact with the light-emitting layer 113. Additionally, when the hole transport layer 112 has a stacked structure, it is preferable to design the light-emitting device in a manner that, when comparing the GSP_slope of the layer in the hole transport layer 112 in contact with the light-emitting layer 113 and the light-emitting layer 113, the GSP_slope has the same size relationship as in structural example 1. This can further improve the luminous efficiency of the light-emitting device.

[0066] In addition, in one embodiment of the light-emitting device of the present invention, the GSP_slope of the layer located on the side of the first electrode 101 in the light-emitting layer 113 and the electron transport layer 114 is preferably smaller than the GSP_slope of the layer located on the side of the second electrode 102 (structural example 2). Figure 2A This illustrates a positively positioned light-emitting device 10A using structural example 2. Figure 2B The inverted light-emitting device 10B using structural example 2 is shown.

[0067] exist Figure 2A In the upright light-emitting device 10A shown, the layer located on the side of the first electrode 101 in the light-emitting layer 113 and the electron transport layer 114 refers to the light-emitting layer 113, and the layer located on the side of the second electrode 102 in the light-emitting layer 113 and the electron transport layer 114 refers to the electron transport layer 114. That is, when the upright light-emitting device 10A adopts structure example 2, the GSP_slope of the light-emitting layer 113 is preferably smaller than the GSP_slope of the electron transport layer 114.

[0068] exist Figure 2B In the upright light-emitting device 10B shown, the layer located on the side of the first electrode 101 in the light-emitting layer 113 and the electron transport layer 114 refers to the electron transport layer 114, and the layer located on the side of the second electrode 102 in the light-emitting layer 113 and the electron transport layer 114 refers to the light-emitting layer 113. That is, when the inverted light-emitting device 10B adopts structure example 2, the GSP_slope of the electron transport layer 114 is preferably smaller than the GSP_slope of the light-emitting layer 113.

[0069] When the upright light-emitting device 10A and the inverted light-emitting device 10B adopt structural example 2, such as Figure 2A and Figure 2BAs shown, the polarization charge on the electron transport layer 114 side of the light-emitting layer 113 cancels out the polarization charge on the light-emitting layer 113 side of the electron transport layer 114. Therefore, it can be considered that a negative interface charge 50b remains at the interface between the light-emitting layer 113 and the electron transport layer 114. Consequently, when holes are attracted from the anode side to this interface, the concentration of excitons in the light-emitting layer 113 on the hole transport layer 112 side is mitigated. Therefore, even in situations such as... Figure 2A and Figure 2B When the GSP_slope of the layer located on the second electrode 102 side of the light-emitting layer 113 and the hole transport layer 112 shown is larger than the GSP_slope of the layer located on the first electrode 101 side, exciton annihilation caused by the interaction between excitons and polarons at the interface between the light-emitting layer 113 and the hole transport layer 112 can be suppressed, thereby improving the luminous efficiency of the light-emitting device. In particular, when structure example 2 is used in a light-emitting device in which a fluorescent luminescent material is used in the light-emitting layer 113 as the light-emitting device and TTA is used to improve the luminous efficiency, the effect of improving the luminous efficiency is high, and therefore it is preferred.

[0070] Furthermore, when the difference between the GSP_slope of the light-emitting layer 113 and the GSP_slope of the electron transport layer 114 is too large in structural example 2, it can be considered that the negative interface charge 50b remaining at the interface between the light-emitting layer 113 and the electron transport layer 114 increases. Therefore, holes are attracted and accumulate at the interface, which sometimes blocks the recombination of charge carriers in the light-emitting layer 113, leading to a decrease in luminous efficiency. Therefore, the difference between the GSP_slope of the light-emitting layer 113 and the GSP_slope of the electron transport layer 114 is preferably 0 mV / nm or more and 20 mV / nm or less. By having this GSP_slope relationship, the luminous efficiency of the light-emitting device can be further improved.

[0071] Furthermore, in one embodiment of the light-emitting device of the present invention, it is preferable that the GSP_slope of the layer located on the side of the second electrode 102 in the light-emitting layer 113 and the hole transport layer 112 is smaller than the GSP_slope of the layer located on the side of the first electrode 101, and that the GSP_slope of the layer located on the side of the first electrode 101 in the light-emitting layer 113 and the electron transport layer 114 is smaller than the GSP_slope of the layer located on the side of the second electrode 102 (structural example 3). Figure 3A This illustrates a positively positioned light-emitting device 10A using structure example 3. Figure 3B The inverted light-emitting device 10B using structural example 3 is shown.

[0072] In other words, when the upright light-emitting device 10A adopts structure example 3, the GSP_slope of the light-emitting layer 113 is preferably smaller than the GSP_slope of the hole transport layer 112 and the GSP_slope of the electron transport layer 114.

[0073] Furthermore, when the inverted light-emitting device 10B adopts structure example 3, the GSP_slope of the light-emitting layer 113 is preferably larger than the GSP_slope of the hole transport layer 112 and the GSP_slope of the electron transport layer 114.

[0074] Therefore, as Figure 3A and Figure 3B As shown, a positive interface charge 50a can be considered to remain at the interface between the hole transport layer 112 and the light-emitting layer 113. Therefore, hole injection from the anode side into the hole transport layer 112 is suppressed, and hole accumulation at the interface can be prevented. As a result, exciton annihilation caused by the interaction between excitons and polarons at the interface can be suppressed. In addition, a negative interface charge 50b can be considered to remain at the interface between the light-emitting layer 113 and the electron transport layer 114. As a result, electrons injected into the electron transport layer 114 from the cathode side are also blocked, and it is easy to maintain a balance between hole injection from the anode side into the light-emitting layer 113 and electron injection from the cathode side into the light-emitting layer 113. Therefore, the luminous efficiency of the light-emitting device can be improved. In particular, when structure example 3 is used in a light-emitting device in which a fluorescent luminescent material is used in the light-emitting layer 113 as the light-emitting device and TTA is used to improve the luminous efficiency, the effect of improving the luminous efficiency is high, so it is preferred.

[0075] Furthermore, in structural example 3, preferably, the difference between the GSP_slope of the light-emitting layer 113 and the GSP_slope of the hole transport layer 112 is 0 mV / nm or more and 20 mV / nm or less, the difference between the GSP_slope of the light-emitting layer 113 and the GSP_slope of the electron transport layer 114 is 0 mV / nm or more and 20 mV / nm or less, and the difference between the GSP_slope of the hole transport layer 112 and the GSP_slope of the electron transport layer 114 is 0 mV / nm or more and 20 mV / nm or less. By having this GSP_slope relationship, the luminous efficiency of the light-emitting device can be further improved.

[0076] Furthermore, when the electron transport layer 114 has a stacked structure in structural examples 2 and 3, it is preferable to compare the GSP_slope of one of the multiple electron transport layers 114 with the GSP_slope of the light-emitting layer 113. Specifically, in the upright type light-emitting device 10A, it is preferable to design the light-emitting device in a manner that, when comparing the GSP_slope of the layer with the largest GSP_slope among the multiple electron transport layers 114 with the GSP_slope of the light-emitting layer 113, the light-emitting device has the same size relationship as in structural examples 2 and 3. Moreover, in the inverted type light-emitting device 10B, it is preferable to design the light-emitting device in a manner that, when comparing the GSP_slope of the layer with the smallest GSP_slope among the multiple electron transport layers 114 with the GSP_slope of the light-emitting layer 113, the light-emitting device has the same size relationship as in structural examples 2 and 3.

[0077] Furthermore, when the hole transport layer 112 has a stacked structure in structural example 3, it is preferable to compare the GSP_slope of one of the multiple hole transport layers 112 with the GSP_slope of the light-emitting layer 113. Specifically, in the upright type light-emitting device 10A, it is preferable to design the light-emitting device in a manner that, when comparing the GSP_slope of the layer with the largest GSP_slope among the multiple hole transport layers 112 with the GSP_slope of the light-emitting layer 113, the size relationship of the GSP_slope in structural example 3 is maintained. Moreover, in the inverted type light-emitting device 10B, it is preferable to design the light-emitting device in a manner that, when comparing the GSP_slope of the layer with the smallest GSP_slope among the multiple hole transport layers 112 with the GSP_slope of the light-emitting layer 113, the size relationship of the GSP_slope in structural example 3 is maintained.

[0078] Furthermore, when the light-emitting layer 113 has a stacked structure in structural examples 1 to 3, it is preferable to compare the GSP_slope of one of the plurality of light-emitting layers 113 with the GSP_slope of the hole transport layer 112 or the electron transport layer 114. Specifically, in the upright type light-emitting device 10A, it is preferable to design the light-emitting device in such a way that when comparing the GSP_slope of the layer with the largest GSP_slope among the plurality of light-emitting layers 113 with the GSP_slope of the hole transport layer 112 or the electron transport layer 114, the size relationship of the GSP_slope in structural examples 1 to 3 is present. Furthermore, in the inverted type light-emitting device 10B, it is preferable to design the light-emitting device in such a way that when comparing the GSP_slope of the layer with the smallest GSP_slope among the plurality of light-emitting layers 113 with the GSP_slope of the hole transport layer 112 or the electron transport layer 114, the size relationship of the GSP_slope in structural examples 1 to 3 is present.

[0079] In addition, when the light-emitting device of one aspect of the present invention includes a plurality of hole transport layers 112 and a plurality of electron transport layers 114, in addition to the above-described structural examples 1 to 3, it is preferable to have the following structure: the GSP_slope of the layer of each hole transport layer 112 located on the side of the second electrode 102 is larger than the GSP_slope of the layer located on the side of the first electrode 101, and the GSP_slope of the layer of each electron transport layer 114 located on the side of the first electrode 101 is larger than the GSP_slope of the layer located on the side of the second electrode 102. For example, when a light-emitting device according to one aspect of the present invention includes two hole transport layers (a first hole transport layer 112_1 and a second hole transport layer 112_2) and two electron transport layers (a first electron transport layer 114_1 and a second electron transport layer 114_2), it preferably has the following structure: the GSP_slope of the layer located on the side of the second electrode 102 in the first hole transport layer 112_1 and the second hole transport layer 112_2 is larger than the GSP_slope of the layer located on the side of the first electrode 101, and the GSP_slope of the layer located on the side of the first electrode 101 in the first electron transport layer 114_1 and the second electron transport layer 114_2 is larger than the GSP_slope of the layer located on the side of the second electrode 102.

[0080] When using Figure 4AIn the upright light-emitting device 10A shown, in the first hole transport layer 112_1 and the second hole transport layer 112_2, the layer located on the side of the second electrode 102 refers to the first hole transport layer 112_1, and the layer located on the side of the first electrode 101 refers to the second hole transport layer 112_2. Similarly, in the first electron transport layer 114_1 and the second electron transport layer 114_2, the layer located on the side of the first electrode 101 refers to the first electron transport layer 114_1, and the layer located on the side of the second electrode 102 refers to the second electron transport layer 114_2. That is, when using... Figure 4A In the case of the upright light-emitting device 10A shown, in addition to the above-described structural examples 1 to 3, it is preferable to have the following structure: the GSP_slope of the first hole transport layer 112_1 is larger than the GSP_slope of the second hole transport layer 112_2, and the GSP_slope of the first electron transport layer 114_1 is larger than the GSP_slope of the second electron transport layer 114_2.

[0081] Therefore, as Figure 4A As shown, a negative interface charge 50b_1 can be considered to remain at the interface between the first hole transport layer 112_1 and the second hole transport layer 112_2. Due to this negative interface charge 50b_1, holes are attracted to the interface from the first electrode 101 side, thus an electric field can be effectively applied to the light-emitting layer 113. Additionally, a positive interface charge 50a_1 can be considered to remain at the interface between the first electron transport layer 114_1 and the second electron transport layer 114_2. Due to this positive interface charge 50a_1, electrons are attracted to the interface from the second electrode 102 side, thus an electric field can be effectively applied to the light-emitting layer 113. Therefore, it is easy to effectively apply an electric field to the light-emitting layer 113, thereby reducing the driving voltage of the light-emitting device.

[0082] On the other hand, when adopting Figure 4B In the inverted light-emitting device 10B shown, in the first hole transport layer 112_1 and the second hole transport layer 112_2, the layer located on the side of the second electrode 102 refers to the second hole transport layer 112_2, and the layer located on the side of the first electrode 101 refers to the first hole transport layer 112_1. Similarly, in the first electron transport layer 114_1 and the second electron transport layer 114_2, the layer located on the side of the second electrode 102 refers to the first electron transport layer 114_1, and the layer located on the side of the first electrode 101 refers to the second electron transport layer 114_2. That is, when using... Figure 4BIn the inverted light-emitting device 10B shown, in addition to the above-described structural examples 1 to 3, it is preferable to have the following structure: the GSP_slope of the second hole transport layer 112_2 is larger than the GSP_slope of the first hole transport layer 112_1, and the GSP_slope of the second electron transport layer 114_2 is larger than the GSP_slope of the first electron transport layer 114_1.

[0083] Therefore, as Figure 4B As shown, a negative interface charge 50b_1 can be considered to remain at the interface between the first hole transport layer 112_1 and the second hole transport layer 112_2. Due to this negative interface charge 50b_1, holes are attracted to the interface from the second electrode 102 side, thus an electric field can be effectively applied to the light-emitting layer 113. Additionally, a positive interface charge 50a_1 can be considered to remain at the interface between the first electron transport layer 114_1 and the second electron transport layer 114_2. Due to this positive interface charge 50a_1, electrons are attracted to the interface from the first electrode 101 side, thus an electric field can be effectively applied to the light-emitting layer 113. Therefore, it is easy to effectively apply an electric field to the light-emitting layer 113, thereby reducing the driving voltage of the light-emitting device.

[0084] <Methods for calculating GSP_slope> Here, we will explain the method for determining the GSP_slope of a film formed by vacuum evaporation.

[0085] As mentioned above, the phenomenon that the surface potential of a vapor-deposited film increases proportionally with its thickness is called the giant surface potential (GSP). Generally, the slope of the surface potential of the vapor-deposited film, measured using a Kelvin probe, plotted along the thickness direction is considered the magnitude of the giant surface potential, denoted as GSP_slope (mV / nm). However, when two different layers are stacked, the charge density accumulated at their interface (mC / m) can be used as the metric. 2 The GSP_slope is estimated by the change in GSP associated with it.

[0086] Non-Patent Document 1 shows that when an organic thin film (thin film 1 and thin film 2) with different spontaneous polarizations is stacked and a voltage is applied, the following formula holds when the charge carriers accumulated at the interface are holes. Note that thin film 1 is located on the anode side and thin film 2 is located on the cathode side. In addition, the anode is located on the substrate side.

[0087] [Equation 1] [Equation 2] In formula (1), σ if_h V represents the interface charge density. iRepresents the hole injection voltage, V bi d2 represents the threshold voltage, d2 represents the thickness of film 2, and ε2 represents the dielectric constant of film 2. i V bi It can be estimated from the capacitance-voltage characteristics of the device. Furthermore, the dielectric constant can be obtained using the ordinary optical refractive index n. o The square of (wavelength 633nm). Thus, V is estimated from the capacitance-voltage characteristic. i V bi The dielectric constant ε2 of thin film 2, calculated from the refractive index, and the thickness d2 of thin film 2, can be used to calculate the interfacial charge density σ using formula (1). if_h .

[0088] Next, in equation (2), σ if_h P represents the interfacial charge density. n ε represents the spontaneous polarization of the thin film n (n is 1 or 2) along the substrate normal direction. n V represents the dielectric constant of thin film n. n d represents the potential at the membrane surface. n This represents the thickness of the thin film n. Furthermore, the potential (V) at the film surface can be used to determine this. n ) divided by thickness (d) n The value obtained is used to calculate GSP_slope. Here, the interface charge density σ can be obtained from the above formula (1). if_h Therefore, by using a material with a known GSP_slope as thin film 2 and adopting a suitable dielectric constant, the GSP_slope of thin film 1 can be estimated.

[0089] The following example illustrates this: As thin film 2, measuring device 1 is fabricated using tris(8-hydroxyquinoline)aluminum (Alq3) with a known GSP_slope of 48 (mV / nm). The GSP_slope of 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB) is determined.

[0090] The device structure of the measuring device 1 is shown in Table 1. Layer 1_1 to the cathode of the measuring device 1 is formed from the anode side by vacuum evaporation at a substrate temperature of room temperature and a deposition rate of 0.2 nm / sec to 0.6 nm / sec. Furthermore, deposition continues without stopping when forming a layer. In the measuring device 1, layer 2_1 corresponds to thin film 1 and layer 3_1 corresponds to thin film 2. Additionally, OCHD-003 is an organic compound with electron acceptor properties.

[0091] Note that, when manufacturing the measurement device, the deposition rate of each layer is preferably 3 nm / min or higher and 600 nm / min or lower. The thickness of each layer in the measurement device is preferably 3 nm or higher and 500 nm or lower, more preferably 50 nm or higher and 300 nm or lower.

[0092] Figure 28 The capacitance-voltage characteristics of measuring device 1 are shown.

[0093] [Table 1] thickness Measuring device 1 cathode 200nm Al Layer 4_1 1nm LiF Layer 3_1 60nm <![CDATA[Alq3]]> Layer 2_1 80nm NPB Layer 1_1 10nm NPB: OCHD-003 (1:0.1) anode 70nm ITSO Table 2 shows the utilization Figure 28 The hole injection voltage V of measuring device 1 is obtained from formulas (1) and (2). i Threshold voltage V bi Interfacial charge density σ if_h GSP_slope, the refractive index n used for calculating NPB. o and the refractive index n of Alq3 o In addition, the refractive index was measured using a spectroscopic ellipsometry (JAWoollam Japan M-2000U).

[0094] [Table 2] Measuring device 1 <![CDATA[Hole injection voltage V1 (V)]]> -0.53 <![CDATA[Threshold voltage V bi (V)]]> 2.02 <![CDATA[Interface charge density σ if_h (mC / m 2 )]]> -1.1 <![CDATA[The ordinary refractive index n of NPB o (@633nm)]]> 1.77 <![CDATA[The ordinary refractive index n of Alq3 o (@633nm)]]> 1.71 GSP_slope(mV / nm) 5.2 Furthermore, a measurement device 2, which has a structure substantially the same as measurement device 1 except that the thickness of Alq3 is 80 nm, was fabricated. It was confirmed that the hole injection voltage drifted to a voltage lower than that of measurement device 1. In other words, it is known that holes are injected first in this device, and charge accumulates at the interface with Alq3. Additionally, it was confirmed that the same results were obtained when estimating the GSP_slope using measurement device 2 as with measurement device 1.

[0095] Furthermore, it is difficult to estimate the threshold voltage V from the capacitance-voltage characteristics. bi In such cases, the threshold voltage estimated from the current density-voltage characteristics can also be used.

[0096] Figure 29 The current density-voltage characteristics of measuring device 1 are shown.

[0097] V estimated from current density-voltage characteristics bi The value is 2.0V, which is the same as the value estimated from the capacitor-voltage characteristic.

[0098] Thus, by fabricating a device that combines a known membrane with an Alq3 membrane of GSP_slope and a membrane formed from an organic compound whose GSP_slope is to be determined, and measuring the capacitance-voltage characteristics, the GSP_slope of the organic compound can be estimated.

[0099] Note that the above explanation describes a method for calculating the GSP_slope when the charge carriers accumulated at the interface become holes. However, when calculating the GSP_slope of an organic film when the charge carriers accumulated at the interface become electrons, it can be calculated similarly using the following formulas (3) and (4). Furthermore, in the following formulas (3) and (4), σ if_e This represents the interface charge density.

[0100] [Equation 3] [Equation 4] The organic compounds used in the light-emitting device are preferably selected based on the GSP_slope of the vapor-deposited film of the organic compound, which is pre-measured by the above measurement method.

[0101] Note that sometimes layers co-deposited with multiple organic compounds are used in light-emitting devices. Since the gas-split slope (GSP) of this layer varies depending on the combination and mixing ratio of the organic compounds in the co-deposited layer, it is ideal to pre-measure the GSP of a film co-deposited using the same combination and mixing ratio of organic compounds as the layer actually used in the light-emitting device, and select the organic compound considering this GSP. However, in this method, different co-deposited films need to be fabricated according to the combination or mixing ratio of organic compounds, and the GSP slope needs to be measured, thus complicating the experiments required to select the organic compound.

[0102] Therefore, in light-emitting devices, when a layer contains multiple organic compounds, it is preferable to select the organic compounds by taking the average value of the pre-measured GSP_slope of the vapor-deposited films of each organic compound as the GSP_slope of that layer. This makes it easier to select organic compounds that take the GSP_slope into account.

[0103] However, even when a layer contains multiple organic compounds, if their contents vary significantly, the GSP_slope of the vapor-deposited film containing the most abundant organic compound can be considered the GSP_slope of that layer. For example, if a layer contains two organic compounds, and the content of one organic compound is less than 20% of the total organic compounds in that layer (wt%), then that organic compound can be identified as a secondary component of that layer, and the other, more abundant organic compound can be identified as the primary component. Therefore, the GSP_slope of the vapor-deposited film containing that primary component can be considered the GSP_slope of that layer. Similarly, if a layer contains three or four organic compounds, and the content of one organic compound is less than 20% of the total organic compounds in that layer (wt%), then that organic compound can be identified as a secondary component of that layer, and the other organic compounds can be identified as the primary components. Therefore, the average GSP_slope of the vapor-deposited films containing each primary component can be considered the GSP_slope of that layer.

[0104] Next, refer to Figure 5A and Figure 5B The light-emitting layer 113 included in the light-emitting device 10A is described. Furthermore, in the light-emitting layer 113, the host material 118 exists in a manner with the largest weight ratio, and the guest material 119 is dispersed in the host material 118.

[0105] Figure 5A The luminescent layer 113 shown comprises a guest material 119 and a host material 118. The guest material 119 is a luminescent substance. In the luminescent layer 113, the content of the guest material 119 is preferably less than 20% (wt%) of the total content of the materials in the layer. Figure 5A The light-emitting layer 113 shown contains a host material 118 as the main component and a guest material 119 as the secondary component. Therefore, it is preferable to regard the GSP_slope of the light-emitting layer 113 containing only one host material as the GSP_slope of the vapor-deposited film of the host material 118 as the main component, and to select organic compounds for each layer of the light-emitting device.

[0106] Figure 5B The light-emitting layer 113 shown comprises a guest material 119, a first host material 118_1, and a second host material 118_2. In the light-emitting layer 113, the contents of the first host material 118_1 and the second host material 118_2 are preferably 25% or more by wt%, and the contents of the guest material 119 are preferably less than 20% by wt% of the total material content in the layer. Therefore, it can be said that… Figure 5BThe light-emitting layer 113 shown comprises two host materials (first host material 118_1 and second host material 118_2) as main components and guest material 119 as a secondary component. Therefore, it is preferable to consider the GSP_slope of the light-emitting layer 113, which is composed mainly of the first host material 118_1 and the second host material 118_2, as the average value of the GSP_slope of the vapor-deposited film of the first host material 118_1 and the GSP_slope of the vapor-deposited film of the second host material 118_2, and select the organic compounds for each layer of the light-emitting device.

[0107] Furthermore, in one embodiment of the light-emitting device of the present invention, a fluorescent light-emitting material is particularly preferred as the guest material 119.

[0108] In addition, such as Figure 5C and Figure 5D As shown, hole transport layer 112 is a layer containing organic compound 112C as its main component, and electron transport layer 114 is a layer containing organic compound 114C as its main component. Additionally, although not shown, the first hole transport layer 112_1 contains organic compound 112_1C as its main component, the second hole transport layer 112_2 contains organic compound 112_2C as its main component, the first electron transport layer 114_1 contains organic compound 114_1C as its main component, and the second electron transport layer 114_2 contains organic compound 114_2C as its main component.

[0109] Note that when the light-emitting layer 113 contains two main materials (first main material 118_1 and second main material 118_2) as main components, the GSP_slope of the vapor-deposited film of the main component of the light-emitting layer 113 refers to the average value of the GSP_slope of the vapor-deposited film of the first main material 118_1 and the GSP_slope of the vapor-deposited film of the second main material 118_2.

[0110] When the light-emitting device 10A and the light-emitting device 10B adopt structural examples 1 to 3, the organic compounds used for each layer are preferably selected as shown in the following examples.

[0111] When structural example 1 is applied to light-emitting devices 10A and 10B, which include a hole transport layer 112 and an electron transport layer 114 (see reference...), Figure 1A and Figure 1B The GSP_slope of the vapor-deposited film of the main component of the layer located on the side of the second electrode 102 in the light-emitting layer 113 and the hole transport layer 112 is preferably smaller than the GSP_slope of the vapor-deposited film of the main component of the layer located on the side of the first electrode 101.

[0112] For example, in the upright light-emitting device 10A (reference) Figure 1A In the case where the light-emitting layer 113 contains a host material 118 as the main component (see reference...), Figure 5A The GSP_slope of the vapor-deposited film of the host material 118 is preferably smaller than that of the vapor-deposited film of the organic compound 112C. More preferably, the difference between the GSP_slope of the vapor-deposited film of the host material 118 and the GSP_slope of the vapor-deposited film of the organic compound 112C is 0 mV / nm or more and 20 mV / nm or less. Furthermore, in the case where the light-emitting layer 113 comprises two host materials (first host material 118_1 and second host material 118_2) (see...) Figure 5B The average value of the GSP_slope of the vapor-deposited film of the first host material 118_1 and the vapor-deposited film of the second host material 118_2 is preferably smaller than that of the vapor-deposited film of the organic compound 112C. More preferably, the difference between the average value of the GSP_slope of the vapor-deposited films of the first host material 118_1 and the second host material 118_2 and the GSP_slope of the vapor-deposited film of the organic compound 112C is 0 mV / nm or more and 20 mV / nm or less. This improves the luminous efficiency of the light-emitting device.

[0113] When structural example 2 is applied to light-emitting devices 10A and 10B, which include a hole transport layer 112 and an electron transport layer 114 (see reference...), Figure 2A and Figure 2B The GSP_slope of the vapor-deposited film of the main component of the layer located on the side of the first electrode 101 in the light-emitting layer 113 and the electron transport layer 114 is preferably smaller than the GSP_slope of the vapor-deposited film of the main component of the layer located on the side of the second electrode 102.

[0114] For example, in the upright light-emitting device 10A (reference) Figure 2A In the case where the light-emitting layer 113 contains a host material 118 as the main component (see reference...), Figure 5A The GSP_slope of the vapor-deposited film of the host material 118 is preferably smaller than that of the vapor-deposited film of the organic compound 114C. More preferably, the difference between the GSP_slope of the vapor-deposited film of the host material 118 and the GSP_slope of the vapor-deposited film of the organic compound 114C is 0 mV / nm or more and 20 mV / nm or less. Furthermore, in the case where the light-emitting layer 113 comprises two host materials (first host material 118_1 and second host material 118_2) (see [reference]). Figure 5BThe average value of the GSP_slope of the vapor-deposited film of the first host material 118_1 and the vapor-deposited film of the second host material 118_2 is preferably smaller than that of the vapor-deposited film of the organic compound 114C. More preferably, the difference between the average value of the GSP_slope of the vapor-deposited film of the first host material 118_1 and the vapor-deposited film of the second host material 118_2 and the GSP_slope of the vapor-deposited film of the organic compound 114C is 0 mV / nm or more and 20 mV / nm or less. This improves the luminous efficiency of the light-emitting device.

[0115] When structural example 3 is applied to light-emitting devices 10A and 10B, which include a hole transport layer 112 and an electron transport layer 114 (see reference...), Figure 3A and Figure 3B Preferably, the vapor deposition GSP_slope of the main component of the layer located on the side of the second electrode 102 in the light-emitting layer 113 and the hole transport layer 112 is smaller than the vapor deposition GSP_slope of the main component of the layer located on the side of the first electrode 101, and the vapor deposition GSP_slope of the main component of the layer located on the side of the first electrode 101 in the light-emitting layer 113 and the electron transport layer 114 is smaller than the vapor deposition GSP_slope of the main component of the layer located on the side of the second electrode 102.

[0116] For example, in the upright light-emitting device 10A (reference) Figure 3A In the case where the light-emitting layer 113 contains a host material 118 as the main component (see reference...), Figure 5A Preferably, the GSP_slope of the vapor-deposited film of the host material 118 is smaller than the GSP_slope of the vapor-deposited film of organic compound 112C and the GSP_slope of the vapor-deposited film of organic compound 114C. More preferably, the difference between the GSP_slope of the vapor-deposited film of the host material 118 and the GSP_slope of the vapor-deposited films of organic compound 112C and organic compound 114C is 0 mV / nm or more and 20 mV / nm or less. Furthermore, in the case where the light-emitting layer 113 comprises two host materials (first host material 118_1 and second host material 118_2) (see [reference]). Figure 5BPreferably, the average value of the GSP_slope of the vapor-deposited film of the first host material 118_1 and the vapor-deposited film of the second host material 118_2 is smaller than the GSP_slope of the vapor-deposited film of organic compound 112C and the vapor-deposited film of organic compound 114C. More preferably, the difference between the average value of the GSP_slope of the vapor-deposited film of the first host material 118_1 and the vapor-deposited film of the second host material 118_2 and the GSP_slope of the vapor-deposited film of organic compound 112C and the vapor-deposited film of organic compound 114C is 0 mV / nm or more and 20 mV / nm or less. This improves the luminous efficiency of the light-emitting device.

[0117] In addition to the above, it is preferable to also have the following structure: Light-emitting device 10A and light-emitting device 10B (refer to) include two hole transport layers (first hole transport layer 112_1 and second hole transport layer 112_2) and two electron transport layers (first electron transport layer 114_1 and second electron transport layer 114_2). Figure 4A and Figure 4B In the first hole transport layer 112_1 and the second hole transport layer 112_2, the vapor deposition film of the main component of the layer located on the side of the second electrode 102 is larger than the vapor deposition film of the main component of the layer located on the side of the first electrode 101, and the vapor deposition film of the main component of the first electron transport layer 114_1 and the second electron transport layer 114_2 located on the side of the first electrode 101 is larger than the vapor deposition film of the main component of the layer located on the side of the second electrode 102.

[0118] For example, in a positively positioned light-emitting device 10A (refer to) comprising two hole transport layers (first hole transport layer 112_1 and second hole transport layer 112_2) and two electron transport layers (first electron transport layer 114_1 and second electron transport layer 1144_2), Figure 4A In the preferred embodiment, the GSP_slope of the vapor-deposited film of organic compound 112_1C is larger than that of the vapor-deposited film of organic compound 112_2C, and the GSP_slope of the vapor-deposited film of organic compound 114_1C is larger than that of the vapor-deposited film of organic compound 114_2C.

[0119] As in the examples above, by selecting organic compounds for each layer, the luminous efficiency of light-emitting devices 10A and 10B can be improved and their driving voltage reduced. Note that the structure of the light-emitting device according to one embodiment of the present invention is not limited to the examples above.

[0120] For example, when a layer using co-deposited organic compounds is used as one or more layers of hole transport layer 112 and electron transport layer 114, the GSP_slope of the film co-deposited using the same combination of organic compounds and the same mixing ratio can be measured in advance, and the organic compound can be selected taking into account the GSP_slope. Alternatively, as described above, the average value of the pre-measured GSP_slope of the deposited films of each organic compound can be taken as the GSP_slope of the layer co-deposited with multiple organic compounds to select the organic compound. Furthermore, as described above, when the contents of the multiple organic compounds in the layer are significantly different, the organic compound with the higher content among the multiple organic compounds can be identified as the main component, and the GSP_slope of the deposited film of that main component can be taken as the GSP_slope of the layer to select the organic compound. In the case where a layer contains two organic compounds or a layer contains three or four organic compounds, the index for the content of the main component or secondary component is as described above, so it is omitted here.

[0121] Furthermore, for example, in a light-emitting device comprising three or more hole transport layers 112 and three or more electron transport layers 114, the organic compound can be selected such that the vapor deposition film of the organic compound used in the layer of the three or more hole transport layers 112 located on the side of the second electrode 102 has a larger GSP_slope than the organic compound used in the layer located on the side of the first electrode 101, and the vapor deposition film of the organic compound used in the layer of the three or more electron transport layers 114 located on the side of the first electrode 101 has a larger GSP_slope than the organic compound used in the layer located on the side of the second electrode 102.

[0122] In addition, when the light-emitting device of one aspect of the present invention has a structure with low refractive index of hole transport layer 112 and electron transport layer 114 in addition to the above-described structure, the light extraction efficiency can be further improved, thereby realizing a very good light-emitting device with high luminous efficiency and low driving voltage.

[0123] Therefore, in addition to GSP_slope, it is more preferable to select organic compounds for each layer of the light-emitting device by taking into account the refractive index of the film of the organic compound measured in advance.

[0124] Additionally, when a layer contains multiple organic compounds, the refractive index of films manufactured using the same combination of organic compounds and the same mixing ratio can be measured in advance, and the organic compounds can be selected taking this refractive index into account. Alternatively, the average refractive index of films containing each organic compound measured in advance can be used as the refractive index of the layer to select the organic compounds.

[0125] However, even when a layer contains multiple organic compounds, if their contents vary significantly, the refractive index of the film containing the most abundant organic compound can be used as the refractive index of the layer. For example, if a layer contains two organic compounds, and the content of one organic compound is less than 20% of the total organic compounds in the layer (wt%), the refractive index of the film containing the other organic compound can be used as the refractive index of the layer, disregarding that organic compound. Furthermore, if a layer contains three or more organic compounds, and the content of one organic compound is less than 20% of the total organic compounds in the layer (wt%), the average refractive index of the films containing the other organic compounds can be used as the refractive index of the layer, disregarding that organic compound.

[0126] In addition, the light-emitting layer 113 (refer to) can contain only one host material. Figure 5A The refractive index of the organic compound used in the light-emitting device is taken as the refractive index of the film of the host material 118.

[0127] In addition, the light-emitting layer 113 containing two host materials (see reference) can be used. Figure 5B The refractive index of the organic compound used in each layer of the light-emitting device is selected by taking the average of the refractive index of the film of the first host material 118_1 and the refractive index of the film of the second host material 118_2.

[0128] Therefore, in light-emitting devices 10A and 10B, when designed in a manner that takes into account the GSP slope and makes the refractive index of hole transport layer 112 and electron transport layer 114 low, the light extraction efficiency of the light-emitting device can be improved by selecting organic compounds for each layer as shown in the examples below.

[0129] For example, in light-emitting devices 10A and 10B (refer to...) including hole transport layer 112 and electron transport layer 114... Figures 1A to 3B In the light-emitting layer 113, only one host material 118 is included (see reference). Figure 5A In the case where, at the peak wavelength of the electroluminescence spectrum of the light-emitting device, at least one of the refractive indices of the film of organic compound 112C and the film of organic compound 114C is more preferably lower than the refractive index of the film of host material 118, and the refractive indices of the two films are further preferably lower than the refractive index of the film of host material 118. Furthermore, in the case where the light-emitting layer 113 comprises two host materials (first host material 118_1 and second host material 118_2) (see...), Figure 5BIn the case of [the above], at the peak wavelength of the electroluminescence spectrum of the light-emitting device, at least one of the refractive index of the film of organic compound 112C and the refractive index of the film of organic compound 114C is more preferably lower than the average of the refractive index of the film of the first host material 118_1 and the refractive index of the film of the second host material 118_2, and the refractive index of these two films is further preferably lower than the average of the refractive index of the film of the first host material 118_1 and the refractive index of the film of the second host material 118_2. Furthermore, in any case, at the peak wavelength of the electroluminescence spectrum of the light-emitting device, at least one of the refractive index of the film of organic compound 112C and the refractive index of the film of organic compound 114C is more preferably 1.75 or less, and the refractive index of these two films is further preferably 1.75 or less.

[0130] Additionally, for example, in light-emitting devices 10A and 10B (refer to) that include two hole transport layers (first hole transport layer 112_1 and second hole transport layer 112_2) and two electron transport layers (first electron transport layer 114_1 and second electron transport layer 114_2), Figure 4A and Figure 4B In the light-emitting layer 113, only one host material 118 is included (see reference). Figure 5A In the case where, at the peak wavelength of the electroluminescence spectrum of the light-emitting device, at least one of the refractive indices of the films of organic compound 112_1C, organic compound 112_2C, organic compound 114_1C, and organic compound 114_2C is more preferably lower than the refractive index of the film of the host material 118, and the refractive indices of two or more films selected from the films of organic compound 112_1C, organic compound 112_2C, organic compound 114_1C, and organic compound 114_2C are further preferably lower than the refractive index of the film of the host material 118. Furthermore, in the case where the light-emitting layer 113 comprises two host materials (first host material 118_1 and second host material 118_2) (see...),... Figure 5BIn the case of a light-emitting device, at the peak wavelength of the electroluminescence spectrum, at least one of the refractive indices of the films of organic compound 112_1C, organic compound 112_2C, organic compound 114_1C, and organic compound 114_2C is preferably lower than the average of the refractive indices of the films of the first host material 118_1 and the second host material 118_2. Furthermore, the refractive indices of two or more films selected from the films of organic compound 112_1C, organic compound 112_2C, organic compound 114_1C, and organic compound 114_2C are preferably lower than the average of the refractive indices of the films of the first host material 118_1 and the second host material 118_2. Furthermore, in any case, at the peak wavelength of the electroluminescence spectrum of the light-emitting device, at least one of the refractive indices of the films of organic compound 112_1C, organic compound 112_2C, organic compound 114_1C, and organic compound 114_2C is more preferably 1.75 or less, and the refractive indices of two or more films selected from the films of organic compound 112_1C, organic compound 112_2C, organic compound 114_1C, and organic compound 114_2C are even more preferably 1.75 or less.

[0131] Note that when the electroemission spectrum of the light-emitting device has multiple peaks, it is preferable that the refractive index of at least one peak wavelength or the wavelength of the largest peak is as described above. Furthermore, the refractive index of the peak wavelengths of the emission spectrum of the light-emitting material used in the light-emitting device can also have the above-described structure. The emission spectrum of the light-emitting material can be measured using a thin film or a solution.

[0132] Furthermore, as a material with a low refractive index, it is preferable to use an organic compound whose polarizability is lower than that of the aromatic skeleton by alkyl groups bonded to the aromatic skeleton. In particular, it is more preferable to use an organic compound having at least one group selected from alkyl groups having 2 to 10 carbon atoms and cycloalkyl groups having 6 to 12 carbon atoms.

[0133] Specific examples of organic compounds used in the light-emitting layer 113, hole transport layer 112, and electron transport layer 114 of a light-emitting device according to one aspect of the present invention are described. Preferably, an organic compound satisfying the above conditions is selected from the specific examples shown below or known organic compounds to manufacture a light-emitting device according to one aspect of the present invention. Example 1 or Example 2 shows the GSP slope and ordinary refractive index of the vapor-deposited films of the organic compounds whose structural formulas are shown below.

[0134] As one aspect of the present invention, the main material 118 of the light-emitting layer 113 of the light-emitting device can be an organic compound with hole transport properties, an organic compound with electron transport properties, a bipolar material, etc.

[0135] Especially in light-emitting devices that use fluorescent luminescent materials as the luminescent layer and utilize TTA to improve luminous efficiency, organic compounds with high singlet excitation energy levels and low triplet excitation energy levels, such as anthracene derivatives, tetraphenyl derivatives, phenanthrene derivatives, and pyrene derivatives, are more preferably used as the host material 118. (chrysene) derivatives, dibenzo[g, p] Derivatives and other fused polycyclic aromatic compounds.

[0136] Specific examples of the main material 118 include 2,9-bis(1-naphthyl)-10-phenylanthracene (abbreviated as: 2αN-αNPhA), 1-[10-(phenyl-2,3,4,5,6-d5)-9-anthrayl]benzo[b]naphtho[2,3-d]furan (abbreviated as: Bnf(II)PhA-02-d5), etc. Their structural formulas are shown below.

[0137] [Chemical Formula 1] Furthermore, in light-emitting devices that use a fluorescent material as the light-emitting layer and utilize TTA to improve luminous efficiency, it is preferable that the lowest singlet excitation energy level (S1 level) of the host material 118 is higher than the S1 energy level of the fluorescent material, and the lowest triplet excitation energy level (T1 level) of the host material 118 is lower than the T1 energy level of the fluorescent material. Additionally, the energy difference between the HOMO energy level of the host material 118 and the HOMO energy level of the fluorescent material is more preferably 0.25 eV or more. Furthermore, the concentration of the fluorescent material in the light-emitting layer relative to the host material 118 is preferably 0.5 wt% or more and 25 wt% or less. By employing this structure, holes are easily trapped within the light-emitting layer, and carrier recombination occurs locally in the region on the hole transport layer side of the light-emitting layer, thereby increasing the exciton density and improving the efficiency of TTA. Furthermore, in other structures utilizing TTA to improve luminous efficiency, the LUMO energy level of the fluorescent material is preferably lower than the LUMO energy level of the host material 118. By adopting this structure, electrons can be easily captured in the light-emitting layer, and carrier recombination occurs locally in the region on the hole transport layer side of the light-emitting layer, thereby increasing the exciton density and thus improving the efficiency of TTA.

[0138] In addition, the values ​​of the HOMO and LUMO energy levels used in this specification can be calculated through electrochemical measurements. Typical examples of electrochemical measurements include cyclic voltammetry (CV) measurements and differential pulse voltammetry (DPV) measurements.

[0139] In cyclic voltammetry (CV) measurements, the oxidation peak potential (Eo) can be obtained by changing the potential of the working electrode relative to the reference electrode. pa) and reduction peak potential (E pc The values ​​(E) of the HOMO and LUMO energy levels were calculated. During the measurement, the HOMO energy level was calculated from a potential scan in the positive direction, and the LUMO energy level was calculated from a potential scan in the negative direction. Furthermore, the scan rate during the measurement was 0.1 V / s.

[0140] Explain the specific methods for calculating the HOMO and LUMO energy levels. The oxidation peak potential (E0) obtained from the cyclic voltammogram of the material is also explained. pa ) and reduction peak potential (E pc Calculate the standard redox potential (E) o (=(E) pa +E pc ) / 2), the potential energy (E) of the reference electrode relative to the vacuum level. x Subtract the standard redox potential (E) o From this, the values ​​(E) of the HOMO and LUMO energy levels can be calculated separately (=E x -E o ).

[0141] Note that the above illustrates the case of obtaining a reversible redox wave. In the case of obtaining an irreversible redox wave, the oxidation peak potential (E) will be used to determine the redox wave. pa The value obtained by subtracting a certain value (0.1 eV) is assumed to be the reduction peak potential (E). pc ), calculate the standard redox potential (E) to one decimal place. o From this, the HOMO energy level can be calculated. Furthermore, the reduction peak potential (E) will be calculated. pc Add a certain value (0.1 eV) and assume it to be the oxidation peak potential (E). pa ), calculate the standard redox potential (E) to one decimal place. o ), thus the LUMO energy level can be calculated.

[0142] Note that the phosphorescent component of the PL spectrum (phosphorescence spectrum) observed at low temperatures (e.g., any temperature within the range of 4K to 80K) can be used as an indicator of the T1 energy level. For example, if the PL spectrum (phosphorescence spectrum) is measured at a measurement temperature of 10K, the energy at the emitting end of the short wavelength side of the phosphorescence spectrum can be considered as the T1 energy level. Conversely, the PL spectrum measured at low temperatures (e.g., any temperature within the range of 4K to 80K) or at room temperature can be used as an indicator of the S1 energy level. For example, the energy at the emitting end of the short wavelength side of the PL spectrum can be considered as the S1 energy level. Furthermore, when fluorescence and phosphorescence spectra are observed in the PL spectrum measured at low temperatures, the energy at the emitting end of the shortest wavelength side of the PL spectrum (fluorescence spectrum) can be considered as the S1 energy level. Additionally, the absorption spectrum measured at room temperature can also be used as an indicator of the S1 energy level of a fluorescent material. For example, the energy at the absorption end of the long wavelength side of the absorption spectrum can be considered as the S1 energy level.

[0143] Additionally, the emitting end on the short-wavelength side of the PL spectrum can be calculated by drawing a tangent at the point where the absolute value of the slope on the short-wavelength side of the peak (or shoulder) observed at the shortest wavelength of the PL spectrum is maximum, and then calculating the emitting end based on the intersection of this tangent with the horizontal axis (wavelength) or the baseline. Similarly, the emitting end on the long-wavelength side of the absorption spectrum can be calculated by drawing a tangent at the point where the absolute value of the slope on the long-wavelength side of the peak (or shoulder) observed at the longest wavelength of the absorption spectrum is maximum, and then calculating the emitting end based on the intersection of this tangent with the horizontal axis (wavelength) or the baseline.

[0144] As the organic compound used in the hole transport layer 112 of the light-emitting device, an organic compound with hole transport properties is preferred. More specifically, organic compounds having an aromatic skeleton or heteroaromatic skeleton such as a π-electron-rich heteroaromatic ring or an aromatic amine skeleton are preferred, and organic compounds containing nitrogen and having a highly symmetrical aromatic skeleton or heteroaromatic skeleton are more preferred. Examples of π-electron-rich heteroaromatic rings include heteroaromatic rings with a pyrrole skeleton, heteroaromatic rings with a furan skeleton, and heteroaromatic rings with a thiophene skeleton. Examples of aromatic skeletons or heteroaromatic skeletons containing nitrogen and having a highly symmetrical skeleton include triphenylamine skeletons and 3,3'-bicarbazole skeletons.

[0145] Specific examples of organic compounds used in hole transport layer 112 include N-(3',5'-di-tert-butylbiphenyl-4-yl)-N-(3',5'-di-tert-butylbiphenyl-2-yl)-9,9-dimethyl-9H-fluorene-2-amine (abbreviated as: dmmtBuopBBAF), N-(3',5'-di-tert-butylbiphenyl-4-yl)-N-(biphenyl-2-yl)-9,9-dimethyl-9H-fluorene-2-amine (abbreviated as: mmtBuBioFBi), N-(biphenyl-2-yl)-N-(3",5',5"-tri-tert-butyl-[1,1':3',1"-tert-butyl]-4-yl)-9,9-dimethyl- Organic compounds with π-electron-rich heteroaromatic rings or aromatic amine skeletons, such as 9H-fluorene-2-amine (abbreviated as mmtBumTPoFBi-04), N,N-bis(biphenyl-4-yl)-9,9'-spirodi[9H-fluorene]-2-amine (abbreviated as BBASF), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirodi[9H-fluorene]-2-amine (abbreviated as PCBASF), and N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviated as PCBiF), are shown below.

[0146] [Chemical Formula 2] Note that among the above-mentioned organic compounds, dmmtBuopBBAF, mmtBuBioFBi, and mmtBumTPoFBi-04 are organic compounds having at least one group selected from alkyl groups having 2 to 10 carbon atoms and cycloalkyl groups having 6 to 12 carbon atoms, and therefore have low refractive indices. Therefore, these organic compounds are more preferably used for the hole transport layer 112 of a light-emitting device.

[0147] As the organic compound used for electron transport layer 114, an organic compound with electron transport properties is preferred. More specifically, an organic compound containing at least one of nitrogen, oxygen, and sulfur atoms and having a highly symmetrical heteroaromatic skeleton is more preferred.

[0148] Specific examples of organic compounds used in electron transport layer 114 include 2-{3-(2,6-dimethylpyridin-3-yl)-5-[(3,5-di-tert-butyl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviated as: mmtBuPh-mDMePyPTzn), 2-[3-(2,6-dimethyl-3-pyridinyl)-5-(9-phenanthyl)phenyl]-4,6-diphenyl-1,3,5-triazine, and 2-[3-(2,6-dimethyl-3-pyridinyl)-5-(9-phenanthyl)phenyl]-4,6-diphenyl-1,3,5-triazine. - Triazine (abbreviation: mPn-mDMePyPTzn), 2-(biphenyl-2-yl)-4-[3-(3,5-dicyclohexylphenyl)-5-(2,6-dimethylpyridin-3-yl)]phenyl-6-phenyl-1,3,5-triazine (abbreviation: oBP-mmchPh-mDMePyPTzn), 2-[3,5-bis(2,6-dimethylpyridin-3-yl)phenyl]-4-(3',5'-di-tert-butylbiphenyl- 4-yl)-6-phenyl-1,3,5-triazine (abbreviation: mmtBuBP-DMePy2PTzn), 2-(2',7'-di-tert-butyl-9,9'-spirobis[9H-fluorene]-2-yl)-4,6-diphenyl-1,3,5-triazine (abbreviation: tBu-SFTzn), 2-[3'-(9,9'-spirobis[9H-fluorene]-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine ( Organic compounds with π-electron-deficient heteroaromatic rings, such as mSFBPTzn, 2,4,6-tris[3'-(pyridin-3-yl)-5'-tert-butyl-biphenyl-3-yl]-1,3,5-triazine (tBu-TmPPPyTz), 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine (TmPPPyTz), and 8-hydroxyquinoline-lithium (Liq), are shown below.

[0149] [Chemical Formula 3] Note that among the above-mentioned organic compounds, mmtBuPh-mDMePyPTzn, oBP-mmchPh-mDMePyPTzn, mmtBuBP-DMePy2PTzn, tBu-SFTzn, and tBu-TmPPPyTz are organic compounds having at least one group selected from alkyl groups having 2 to 10 carbon atoms and cycloalkyl groups having 6 to 12 carbon atoms, and therefore have low refractive indices. Therefore, these organic compounds are more preferably used for the electron transport layer 114.

[0150] Note that the organic compounds that can be used in the light-emitting device according to one aspect of the present invention are not limited to the specific examples described above.

[0151] Furthermore, the structure shown in this embodiment can be used in appropriate combinations with the structures shown in other embodiments.

[0152] Implementation Method 2 In this embodiment, refer to Figures 6A to 6E Other structures of the light-emitting device according to one aspect of the present invention will be described.

[0153] <Basic Structure of Light-Emitting Devices> The basic structure of light-emitting devices is explained. Figure 6A This illustrates a light-emitting device with a structure (single structure) comprising an organic compound layer having a light-emitting layer between a pair of electrodes. Specifically, an organic compound layer 103 is sandwiched between the first electrode 101 and the second electrode 102.

[0154] also, Figure 6B This shows that multiple ( ) are included between a pair of electrodes. Figure 6B A light-emitting device is a stacked structure (tandem structure) consisting of two organic compound layers (103a, 103b) and a charge-generating layer 106 between the organic compound layers. The tandem structure allows for high-efficiency light emission without changing the current.

[0155] The charge generation layer 106 functions as follows: when a potential difference is generated between the first electrode 101 and the second electrode 102, it injects electrons into one organic compound layer (103a or 103b) and injects holes into the other organic compound layer (103b or 103a). Thus, in Figure 6B When a voltage is applied in such a way that the potential of the first electrode 101 is higher than the potential of the second electrode 102, electrons are injected from the charge generation layer 106 into the organic compound layer 103a and holes are injected into the organic compound layer 103b.

[0156] Furthermore, from the viewpoint of light extraction efficiency, the charge generation layer 106 preferably has light transmittance to visible light (specifically, the visible light transmittance of the charge generation layer 106 is 40% or more). Moreover, it functions even if the electrical conductivity of the charge generation layer 106 is lower than that of the first electrode 101 and the second electrode 102.

[0157] also, Figure 6CThe diagram illustrates a stacked structure of an organic compound layer 103 in a light-emitting device according to one embodiment of the present invention. Note that in this case, the first electrode 101 is used as the anode, and the second electrode 102 is used as the cathode. The organic compound layer 103 has a structure in which a hole injection layer 111, a hole transport layer 112, a light-emitting layer 113, an electron transport layer 114, and an electron injection layer 115 are sequentially stacked on the first electrode 101. Note that the light-emitting layer 113 may also have a structure of stacked multiple light-emitting layers with different emission colors. For example, light-emitting layers containing red, green, and blue light-emitting materials may be stacked with or without separation between layers containing carrier transport materials. Alternatively, a light-emitting layer containing yellow and a light-emitting layer containing blue light-emitting materials may be combined. Note that the stacked structure of the light-emitting layer 113 is not limited to the above structures. For example, the light-emitting layer 113 may also have a structure of stacked multiple light-emitting layers with the same emission color. For example, a first luminescent layer containing a blue luminescent material and a second luminescent layer containing a blue luminescent material can be stacked, with or without separation of layers containing charge carrier transport materials. When multiple luminescent layers of the same color are stacked, reliability can sometimes be improved compared to a single-layer structure. Furthermore, in situations such as... Figure 6B In the case of a series structure with multiple organic compound layers, each organic compound layer also has a structure in which they are stacked sequentially from the anode side as described above. Furthermore, when the first electrode 101 is used as the cathode and the second electrode 102 is used as the anode, the stacking order of the organic compound layers 103 is reversed. Specifically, on the first electrode 101 used as the cathode, 111 is an electron injection layer, 112 is an electron transport layer, 113 is a light-emitting layer, 114 is a hole transport layer, and 115 is a hole injection layer.

[0158] By appropriately combining luminescent layers 113 within the organic compound layers (103, 103a, 103b) containing luminescent materials and multiple substances, fluorescent or phosphorescent emission exhibiting the desired emission color can be obtained. Furthermore, the luminescent layers 113 can also be a stacked structure with different emission colors. In this case, different materials can be used as the luminescent materials and other substances for each luminescent layer used in the stacking. Alternatively, materials from... Figure 6B The structure shown has multiple organic compound layers (103a, 103b) that produce different luminescent colors. In this case, different materials can be used as the luminescent material and other substances for each luminescent layer.

[0159] Furthermore, in one embodiment of the light-emitting device of the present invention, for example, by making Figure 6CThe first electrode 101 shown is a reflective electrode, and the second electrode 102 is a semi-transmissive-semi-reflective electrode with an optical microcavity resonator (microcavity) structure. This allows the light emitted from the light-emitting layer 113 in the organic compound layer 103 to resonate between the two electrodes, thereby enhancing the light emitted from the second electrode 102. This facilitates high-definition imaging. Furthermore, because the light emission intensity in the frontal direction at a specific wavelength can be enhanced, low power consumption can be achieved.

[0160] When the first electrode 101 of the light-emitting device is a reflective electrode composed of a stacked structure of a reflective conductive material and a light-transmitting conductive material (transparent conductive film), optical adjustment can be performed by adjusting the thickness of the transparent conductive film. Specifically, it is preferable to adjust the thickness of the transparent conductive film so that when the wavelength of the light obtained from the light-emitting layer 113 is λ, the optical distance (product of thickness and refractive index) between the first electrode 101 and the second electrode 102 is mλ / 2 (note that m is an integer greater than or equal to 1) or a value close to it.

[0161] Furthermore, in order to amplify the desired light obtained from the light-emitting layer 113 at the desired wavelength (wavelength: λ), it is preferable to adjust the optical distances from the first electrode 101 to the region in the light-emitting layer 113 where light emission is possible (light-emitting region) and from the second electrode 102 to the region in the light-emitting layer 113 where light emission is possible (light-emitting region) to be (2m'+1)λ / 4 (note that m' is an integer greater than or equal to 1) or a value close to that. Note that the light-emitting region described here refers to the recombination region of holes and electrons in the light-emitting layer 113.

[0162] By making the above optical adjustments, the spectrum of specific monochromatic light that can be obtained from the light-emitting layer 113 can be narrowed, thereby obtaining light emission with good color purity.

[0163] Furthermore, in the above-described case, strictly speaking, the optical distance between the first electrode 101 and the second electrode 102 can be considered as the total thickness from the reflective region in the first electrode 101 to the reflective region in the second electrode 102. However, since it is difficult to accurately determine the positions of the reflective regions in the first electrode 101 and the second electrode 102, the aforementioned effect can be sufficiently obtained by assuming any position in the first electrode 101 and the second electrode 102 as a reflective region. Furthermore, strictly speaking, the optical distance between the first electrode 101 and the light-emitting layer can be considered as the optical distance between the reflective region in the first electrode 101 and the light-emitting region in the light-emitting layer. However, since it is difficult to accurately determine the reflective region in the first electrode 101 and the light-emitting region in the light-emitting layer, the aforementioned effect can be sufficiently obtained by assuming any position in the first electrode 101 as a reflective region and any position in the light-emitting layer as a light-emitting region.

[0164] Figure 6D The light-emitting device shown is a series-connected device. By employing a series structure, a light-emitting device capable of high brightness can be achieved. Furthermore, the series structure improves reliability because it reduces the current required to achieve the same brightness compared to a single structure. Additionally, power consumption can be reduced.

[0165] Figure 6E The light-emitting device shown is Figure 6B An example of a series-connected light-emitting device, as shown in the attached figure, has a structure in which three organic compound layers (103a, 103b, 103c) sandwich a charge-generating layer (106a, 106b) stacked together. Furthermore, each of the three organic compound layers (103a, 103b, 103c) includes a light-emitting layer (113a, 113b, 113c), and the emission colors of each light-emitting layer can be freely combined. For example, a structure can be adopted where light-emitting layer 113a is blue, light-emitting layer 113b is any one of red, green, and yellow, and light-emitting layer 113c is blue; alternatively, a structure can be adopted where light-emitting layer 113a is red, light-emitting layer 113b is any one of blue, green, and yellow, and light-emitting layer 113c is red.

[0166] Furthermore, in the light-emitting device according to one aspect of the present invention described above, at least one of the first electrode 101 and the second electrode 102 is a light-transmitting electrode (transparent electrode, semi-transmissive-semi-reflective electrode, etc.). When the light-transmitting electrode is a transparent electrode, the transmittance of visible light by the transparent electrode is 40% or more. Furthermore, when the electrode is a semi-transmissive-semi-reflective electrode, the reflectance of visible light by the semi-transmissive-semi-reflective electrode is 20% or more and 80% or less, preferably 40% or more and 70% or less. Moreover, the resistivity of these electrodes is preferably 1 × 10⁻⁶. -2 Below Ω·cm.

[0167] Furthermore, in the light-emitting device according to one aspect of the present invention, when one of the first electrode 101 and the second electrode 102 is a reflective electrode (reflective electrode), the visible light reflectance of the reflective electrode is 40% or more and 100% or less, preferably 70% or more and 100% or less. Furthermore, the resistivity of this electrode is preferably 1 × 10⁻⁶. -2 Below Ω·cm.

[0168] <Specific Structure of Light-Emitting Devices> Next, a specific structure of a light-emitting device according to one aspect of the present invention will be described. Furthermore, reference is made here to a device having a series structure. Figure 6D Please explain. Note that... Figure 6A and Figure 6CThe light-emitting device with a single structure shown also employs the same organic compound layer structure. Furthermore, in Figure 6D In the case of a light-emitting device having a microcavity structure, a reflective electrode is formed as the first electrode 101, and a transmissive-reflective electrode is formed as the second electrode 102. Thus, the electrodes can be formed in a single layer or in a stack using a desired electrode material alone or using multiple electrode materials. Furthermore, the second electrode 102 is formed by appropriately selecting a material after forming the organic compound layer 103b.

[0169] Materials for Light-Emitting Devices Luminescent Layer The luminescent layers (113, 113a, 113b) are layers containing luminescent materials. Note that materials exhibiting luminescent colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, and red can be appropriately used as luminescent materials for the luminescent layers (113, 113a, 113b). Furthermore, when multiple luminescent layers are included, by using different luminescent materials in each luminescent layer, structures exhibiting different luminescent colors can be obtained (e.g., white light obtained by combining luminescent colors that are complementary colors). Alternatively, a stacked structure in which a single luminescent layer contains different luminescent materials can also be used.

[0170] Furthermore, the light-emitting layers (113, 113a, 113b) may contain one or more organic compounds (host materials, etc.) in addition to the luminescent material (guest material). When multiple host materials are used in the light-emitting layers (113, 113a, 113b), the material described in Embodiment 1 can be used as the light-emitting layer, for example. Figure 5B The structure is described below. In this light-emitting layer, the host material 118 has the largest weight ratio, and the guest material 119 is dispersed in the host material 118. The T1 energy level of the host material 118 (first host material 118_1 and second host material 118_2) of this light-emitting layer is preferably higher than the T1 energy level of the guest material (guest material 119).

[0171] As the first host material 118_1, a material with higher electron transport properties than hole transport properties can be used, preferably one with 1×10⁻⁶. -6 cm 2Materials with electron mobilities of / Vs or higher. As materials that readily accept electrons (materials with electron transport properties), compounds with π-electron-deficient heteroaromatic ring skeletons, such as nitrogen-containing heteroaromatic compounds, and zinc or aluminum metal complexes can be used. Examples of compounds with π-electron-deficient heteroaromatic ring skeletons include oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, phenanthroline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and triazine derivatives. Examples of zinc or aluminum metal complexes include metal complexes with quinoline ligands, benzoquinoline ligands, oxazole ligands, or thiazole ligands.

[0172] Specifically, examples include metal complexes with quinoline or benzoquinoline skeletons, such as tris(8-hydroxyquinoline)aluminum(III) (Alq), tris(4-methyl-8-hydroxyquinoline)aluminum(III) (Almq3), bis(10-hydroxybenzo[h]quinoline)beryllium(II) (BeBq2), bis(2-methyl-8-hydroxyquinoline)(4-phenylphenol)aluminum(III) (BAlq), and bis(8-hydroxyquinoline)zinc(II) (Znq). In addition to the above, metal complexes with oxazole or thiazole ligands, such as bis[2-(2-benzoxazolyl)phenol]zinc(II) (ZnPBO) and bis[2-(2-benzothiazolyl)phenol]zinc(II) (ZnBTZ), can also be used. Furthermore, besides metal complexes, 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated as PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (abbreviated as OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviated as CO11), and 3-(4-biphenyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole ( Abbreviations: TAZ), 9-[4-(4,5-diphenyl-4H-1,2,4-triazol-3-yl)phenyl]-9H-carbazole (abbreviation: CzTAZ1), 2,2',2”-(1,3,5-phenyltriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophene-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), phenanthroline (abbreviation: BPhen), copper bath (abbreviation: BCP), and other heterocyclic compounds. Compounds, 2-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4-(3,6-diphenyl-9H-carbazole-9-yl)phenyl] Dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), 6-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 2-[3-([3,9'-bi-9H-carbazole]-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzCzPDBq), 4,Heterocyclic compounds with a diazine skeleton, such as 6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviated as: 4,6mPnP2Pm), 4,6-bis[3-(dibenzothiophene-4-yl)phenyl]pyrimidine (abbreviated as: 4,6mDBTP2Pm-II), and 4,6-bis[3-(9H-carbazole-9-yl)phenyl]pyrimidine (abbreviated as: 4,6mCzP2Pm), and 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl} Heterocyclic compounds with a triazine skeleton, such as 4,6-diphenyl-1,3,5-triazine (abbreviated as PCCzPTzn), heterocyclic compounds with a pyridine skeleton, such as 3,5-bis[3-(9H-carbazole-9-yl)phenyl]pyridine (abbreviated as 35DCzPPy) and 1,3,5-tris[3-(3-pyridyl)phenyl]benzene (abbreviated as TmPyPB), and heteroaromatic compounds such as 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviated as BzOs), are preferred. Among these heterocyclic compounds, those with a triazine skeleton, a diazine (pyrimidine, pyrazine, pyridazine) skeleton, or a pyridine skeleton are stable and reliable. Heterocyclic compounds with this skeleton have high electron transport properties, which also helps to reduce the driving voltage. In addition, polymeric compounds such as poly(2,5-pyridindiyl) (abbreviated as PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridin-3,5-diyl)] (abbreviated as PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridin-6,6'-diyl)] (abbreviated as PF-BPy) can also be used. The substances described here are primarily those with a concentration of 1 × 10⁻⁶. -6 cm 2 Substances with an electron mobility of / Vs or higher. Note that any substance other than those mentioned above can also be used, as long as its electron transport is higher than its hole transport.

[0173] As the second host material 118_2, it is preferable to use a combination that can form an excimer complex with the first host material 118_1. Specifically, it is preferable to have a π-electron-rich heteroaromatic ring or a highly donor-oriented skeleton such as an aromatic amine skeleton. Examples of compounds with π-electron-rich heteroaromatic rings include dibenzothiophene derivatives, dibenzofuran derivatives, and carbazole derivatives. In this case, it is preferable to select the first host material 118_1, the second host material 118_2, and the guest material 119 in such a way that the emission peak of the excimer complex formed by the first host material 118_1 and the second host material 118_2 overlaps with the absorption band of the triple MLCT (Metal to Ligand Charge Transfer) transition of the guest material 119, more specifically, the absorption band at the longest wavelength. As a result, a light-emitting device with significantly improved luminescence efficiency can be realized. Note that when using a thermally activated delayed fluorescence material as the guest material 119, the absorption band at the longest wavelength is preferably a singlet absorption band.

[0174] As the second main material 118_2, the following hole transport materials can be used. As the hole transport material, materials with higher hole transport properties than electron transport properties can be used, preferably those with a hole transport property of 1×10⁻⁶. -6 cm 2 Materials with hole mobility of / Vs or higher can be used. Specifically, aromatic amines, carbazole derivatives, aromatic hydrocarbons, stilbene derivatives, etc., can be used. The aforementioned hole transport materials can also be polymer compounds.

[0175] As materials with high hole transport properties, specifically, as aromatic amine compounds, examples include N,N'-bis(p-tolyl)-N,N'-diphenyl-p-phenylene diamine (DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (DPAB), N,N'-bis[4-bis(3-methylphenyl)aminophenyl]-N,N'-diphenyl-4,4'-diaminobiphenyl (DNTPD), and 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (DPA3B), etc.

[0176] In addition, as carbazole derivatives, specifically, examples include 3-[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviated as PCzDPA1), 3,6-bis[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviated as PCzDPA2), and 3,6-bis[N-(4-diphenylaminophenyl)-N-(1-naphthyl)amino]-9-phenylcarbazole (abbreviated as PCzDPA2). Examples of such products include PCzTPN2, 3-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviated as PCzPCA1), 3,6-bis[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviated as PCzPCA2), and 3-[N-(1-naphthyl)-N-(9-phenylcarbazole-3-yl)amino]-9-phenylcarbazole (abbreviated as PCzPCN1).

[0177] In addition, other examples of carbazole derivatives include 4,4'-bis(N-carbazolyl)biphenyl (CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (TCPB), 9-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole (CzPA), and 1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene.

[0178] In addition, examples of aromatic hydrocarbons include 2-tert-butyl-9,10-bis(2-naphthyl)anthracene (t-BuDNA), 2-tert-butyl-9,10-bis(1-naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene (DPPA), 2-tert-butyl-9,10-bis(4-phenylphenyl)anthracene (t-BuDBA), 9,10-bis(2-naphthyl)anthracene (DNA), 9,10-diphenylanthracene (DPAnth), 2-tert-butylanthracene (t-BuAnth), and 9,10-bis(4-methyl-1-naphthyl)anthracene (DMNA). ), 2-tert-butyl-9,10-bis[2-(1-naphthyl)phenyl]anthracene, 9,10-bis[2-(1-naphthyl)phenyl]anthracene, 2,3,6,7-tetramethyl-9,10-bis(1-naphthyl)anthracene, 2,3,6,7-tetramethyl-9,10-bis(2-naphthyl)anthracene, 9,9'-bianthracene, 10,10'-diphenyl-9,9'-bianthracene, 10,10'-bis(2-phenylphenyl)-9,9'-bianthracene, 10,10'-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9'-bianthracene, anthracene, tetraphenylene, rubrogene, perylene, 2,5,8,11-tetra-tert-butylperylene, etc. In addition, pentaphenylene, benzobenzene, etc., can also be used. As described above, it is more preferable to use a compound with 1×10 -6 cm 2Aromatic hydrocarbons with a hole mobility of / Vs or higher and a carbon number of 14 or more and 42 or less.

[0179] Note that aromatic hydrocarbons can also have a vinyl skeleton. Examples of aromatic hydrocarbons with a vinyl skeleton include 4,4'-bis(2,2-diphenylvinyl)biphenyl (abbreviated as DPVBi) and 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviated as DPVPA).

[0180] In addition, polymers such as poly(N-vinylcarbazole) (PVK), poly(4-vinyltriphenylamine) (PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (PTPDMA) or poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (Poly-TPD) can also be used.

[0181] In addition, materials with high hole transport properties can be used, for example, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (TPD), 4,4',4”-tris(carbazole-9-yl)triphenylamine (TCTA), 4,4',4”-tris[N-(1-naphthyl)-N-phenylamino]triphenylamine (1'-TNATA), 4,4',4”-tris(N,N-diphenylamino)triphenylamine (TDATA), 4,4',4”- Tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: m-MTDATA), N,N'-bis(9,9'-spirobis[9H-fluorene]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluorene-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluorene-9-yl)triphenylamine (abbreviation: mBPAFLP), N-(9,9-dimethyl-9H-fluorene-2-yl)-N-{9,9-dimethyl-2-[N'-phenyl-N'-(9,9-dimethyl- [9H-fluorene-2-yl]amino]-9H-fluorene-7-yl}phenylamine (abbreviation: DFLADFL), N-(9,9-dimethyl-2-diphenylamino-9H-fluorene-7-yl)diphenylamine (abbreviation: DPNF), N-(9,9-spirobis[9H-fluorene]-2-yl)-N,N'N'-triphenyl-1,4-phenylene diamine (abbreviation: DPASF), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4”-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBBilB) P), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-bis(1-naphthyl)-4”-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCCNBB), 4-phenyldiphenyl-(9-phenyl-9H-carbazole-3-yl)amine (abbreviation: PCA1BP), N,N'-bis(9-phenylcarbazole-3-yl)-N,N'-diphenylphenyl-1,3-diamine (abbreviation: PCA2B), N,N',N”-triphenyl-N,N',N”-tris(9-phenylcarbazole-3-yl)phenyl-1,35-Triamine (abbreviated as PCA3B), N-(9,9-diphenyl-9H-fluoren-2-yl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviated as PCAFLP(2)), N-(9,9-diphenyl-9H-fluoren-2-yl)-N,9-diphenyl-9H-carbazole-2-amine (abbreviated as PCAFLP(2)-02), N-(biphenyl-4-yl)-N-(9, 9-Dimethyl-9H-fluorene-2-yl)-9-phenyl-9H-carbazole-3-amine (abbreviated as: PCBiF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviated as: PCBiF), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl Fluorene-2-amine (abbreviated as PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirodi[9H-fluorene]-2-amine (abbreviated as PCBAF), N-(9,9-spirodi[9H-fluorene]-2-yl)-N,9-diphenylcarbazole-3-amine (abbreviated as PCASF), N,N'-diphenyl-N,N'-bis(4-diphenyl) Aromatic amine compounds such as (4-(9H-carbazole-9-yl)phenyl)spirodi[9H-fluorene]-2,7-diamine (abbreviated as DPA2SF), N-[4-(9H-carbazole-9-yl)phenyl]-N-(4-phenyl)phenylaniline (abbreviated as YGA1BP), and N,N'-bis[4-(carbazole-9-yl)phenyl]-N,N'-diphenyl-9,9-dimethylfluorene-2,7-diamine (abbreviated as YGA2F). In addition, 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPN), 9-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]phenanthrene (abbreviated as PCPPn), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviated as PCCP), 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviated as BisBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H-3,3'-bicarbazole (abbreviated as mRPCCBP), and 9-(2-naphthyl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviated as β) can be used. NCCP), 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: Bisβ NCz), 9-[3-(triphenylsilyl)phenyl]-3,9'-bi-9H-carbazole (abbreviation: PSiCzCz), 1,3-bis(N-carbazolyl)phenyl (abbreviation: mCP), 3,6-bis(3,5-Diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 3,6-bis(9H-carbazol-9-yl)-9-phenyl-9H-carbazole (abbreviation: PhCzGI), 2,8-bis(9H-carbazol-9-yl)dibenzothiophene (abbreviation: Cz2DBT), 4-{3-[3-(9-phenyl-9H-fluorene-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II), 4,4',4”-(benzene-1,3,5-triyl)tris(dibenzofuran) (abbreviation: DBF3P-II), 4,4',4”-(benzene-1,3, The compounds include amine compounds such as 5-triyl)tris(dibenzothiophene) (abbreviated as DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluorene-9-yl)phenyl]dibenzothiophene (abbreviated as DBTFLP-III), 4-[4-(9-phenyl-9H-fluorene-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as DBTFLP-IV), and 4-[3-(triphenyl-2-yl)phenyl]dibenzothiophene (abbreviated as mDBTPTp-II), as well as carbazole compounds, thiophene compounds, furan compounds, fluorene compounds, triphenylene compounds, and phenanthrene compounds. Among these compounds, those with pyrrole, furan, thiophene, or aromatic amine skeletons are stable and reliable, and are therefore preferred. Furthermore, compounds with such skeletons exhibit high hole transport properties, which also helps to reduce the driving voltage.

[0182] When an organic compound with electron transport capabilities is used as the first host material 118_1 and an organic compound with hole transport capabilities is used as the second host material 118_2, the HOMO energy level of the organic compound with hole transport capabilities is preferably higher than or equal to the HOMO energy level of the organic compound with electron transport capabilities. Furthermore, when the LUMO energy level of the organic compound with hole transport capabilities is higher than or equal to the LUMO energy level of the organic compound with electron transport capabilities, the excitocomplex can be formed more efficiently, and this is therefore preferred.

[0183] There are no particular restrictions on the guest material 119 that can be used in the light-emitting layers (113, 113a, 113b). Light-emitting materials that convert single excitation energy into light emission in the visible light region or light-emitting materials that convert triple excitation energy into light emission in the visible light region can be used.

[0184] Luminescent materials that convert singlet excitation energy into luminescence As luminescent materials that convert singlet excitation energy into luminescence and can be used in luminescent layers (113, 113a, 113b), the following fluorescent materials (fluorescent luminescent materials) can be cited. Examples include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives. Pyrene derivatives, in particular, have a high luminescence quantum yield and are therefore preferred. Specific examples of pyrene derivatives include N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviated as: 1,6mMemFLPAPrn), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviated as: 1,6FLPAPrn), N,N'-bis(dibenzofuran-2-yl)-N,N'-diphenylpyrene-1,6-diamine (abbreviated as: 1,6FrAPrn), and N,N'-bis(dibenzothiophene-2-yl)-N,N' 1,6-Diphenylpyrene-1,6-diamine (abbreviated as: 1,6ThAPrn), N,N'-(pyrene-1,6-diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-6-amine] (abbreviated as: 1,6BnfAPrn), N,N'-(pyrene-1,6-diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviated as: 1,6BnfAPrn-02), N,N'-(pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviated as: 1,6BnfAPrn-03), etc.

[0185] In addition, 5,6-bis[4-(10-phenyl-9-anthrayl)phenyl]-2,2'-bipyridine (abbreviated as: PAP2BPy), 5,6-bis[4'-(10-phenyl-9-anthrayl)biphenyl-4-yl]-2,2'-bipyridine (abbreviated as: PAPP2BPy), and N,N'-bis[4-(9H-carbazole-9-yl)phenyl]-N,N'-diphenyl-4,4'-stilbenediamine (abbreviated as: Y) can be used. GA2S), 4-(9H-carbazole-9-yl)-4'-(10-phenyl-9-anthrayl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-diphenyl-2-anthrayl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole-3-amine (abbreviation: PCAPA), 4-(10 4-[4-(10-phenyl-9-anthrayl)phenyl]-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCPAPA), 4-[4-(10-phenyl-9-anthrayl)phenyl]-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCPABA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), N,N”-(2-tert-butylanthracene-9,10-diyldi-4,1) 3-phenylene)bis(N,N',N'-triphenyl-1,4-phenylene diamine) (abbreviated as DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthrayl)phenyl]-9H-carbazole-3-amine (abbreviated as 2PCAPPA), N-[4-(9,10-diphenyl-2-anthrayl)phenyl]-N,N',N'-triphenyl-1,4-phenylene diamine (abbreviated as 2DPAPPA), etc.

[0186] In addition, N,N,N',N',N",N",N",N"',N"'-octaphenyldibenzo[g,p] can be cited as an example. -2,7,10,15-Tetraamine (abbreviation: DBC1), Coumarin 30, N-(9,10-diphenyl-2-anthrayl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthrayl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCABPhA), N-(9,10- Diphenyl-2-anthrayl)-N,N',N'-triphenyl-1,4-phenylene diamine (abbreviated as: 2DPAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthrayl]-N,N',N'-triphenyl-1,4-phenylene diamine (abbreviated as: 2DPABPhA), 9,10-bis(biphenyl-2-yl)-N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylanthracene-2-amine (abbreviated as: 2YGABPhA), N,N,9-triphenylanthracene-9-amine (abbreviated as: DPhAPhA), coumarin 545T, N,N'-diphenylquinacridone (abbreviated as: DPQd), rubrene, 5,12-bis(biphenyl-4-yl)-6,11-diphenyltetraphenyl (abbreviated as: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]ethylene 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinazine-9-yl)vinyl]-4H-pyran-4-yl}malononitrile (abbreviated as: DCM1), N,N,N',N'-tetra(4-methylphenyl)tetraphenyl-5,11-diamine (abbreviated as: p) - mPhTD), 7,14-diphenyl-N,N,N',N'-tetra(4-methylphenyl)acenaphthene[1,2-a]fluoranthene-3,10-diamine (abbreviated as: p) -mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinazin-9-yl)vinyl]-4H-pyran-4-ylidene}malonium (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinazin-9-yl)vinyl]-4H-pyran-4-ylidene}malonium (abbreviation: DCJTB), 2-(2,6-bis{2-[4-(dimethylamino)phenyl]vinyl}-4H-pyran-4-ylidene)malonium (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy) -1,1,7,7-Tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinazine-9-yl]vinyl]-4H-pyran-4-ylidene}malononitrile (abbreviation: BisDCJTM), 1,6BnfAPrn-03, N,N'-diphenyl-N,N'-bis(9-phenyl-9H-carbazole-2-yl)naphtho[2,3-b;6,7-b']bisbenzofuran-3,10-diamine (abbreviation: 3,10PCA2Nbf(IV)-02), N,N'-bis(dibenzofuran-3-yl)-N,N'-diphenylnaphtho[2,3-b;6,7-b']bisbenzofuran-3,10-diamine (abbreviation: 3,10FrA2Nbf(IV)-02), etc. In particular, pyrene diamine compounds such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03 can be used.

[0187] In addition, 5,9-diphenyl-5H,9H-[1,4]benzozaborane[2,3,4-kl]phenazaborane (abbreviated as DABNA-1), 9-(biphenyl-3-yl)-N,N,5,11-tetraphenyl-5H,9H-[1,4]benzozaborane[2,3,4-kl]phenazabor-3-amine (abbreviated as DABNA-2), and 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl) can be used appropriately. -N,N-diphenyl-5H,9H-[1,4]benzozaborane[2,3,4-kl]phenazaboron-7-amine (abbreviation: DPhA-tBu4DABNA), 2,12-di(tert-butyl)-N,N,5,9-tetra(4-tert-butylphenyl)-5H,9H-[1,4]benzozaborane[2,3,4-kl]phenazaboron-7-amine (abbreviation: tBuDPhA-tBu4DABNA), 2,12-di( tert-Butyl)-5,9-di(4-tert-butylphenyl)-7-methyl-5H,9H-[1,4]benzozaborane[2,3,4-kl]phenazaborane (abbreviation: Me-tBu4DABNA), N7,N7,N13,N13,5,9,11,15-octaphenyl-5H,9H,11H,15H-[1,4]benzozaborane[2,3,4-kl][1,4]benzozaborane[4',3',2':4, Nitrogen- and boron-containing fused heteroaromatic compounds, such as [5][1,4]benzozaborane[3,2-b]phenazabor-7,13-diamine (abbreviation: v-DABNA), 2-(4-tert-butylphenyl)benzo[5,6]indolo[3,2,1-jk]benzo[b]carbazole (abbreviation: tBuPBibc), especially compounds with a diazaboranenaphthalene-anthracene skeleton, can produce blue luminescence with good color purity due to their narrow emission spectrum.

[0188] In addition, 9,10,11-tris[3,6-bis(1,1-dimethylethyl)-9H-carbazolyl-9-yl]-2,5,15,18-tetra(1,1-dimethylethyl)indolo[3,2,1-de]indolo[3',2',1':8,1][1,4]benzozaborane[2,3,4-kl]phenazaborane (abbreviated as: BBCz-G) can be appropriately used. Compounds with an indole skeleton, such as 9,11-bis[3,6-bis(1,1-dimethylethyl)-9H-carbazolyl-9-yl]-2,5,15,18-tetra(1,1-dimethylethyl)indolo[3,2,1-de]indolo[3',2',1':8,1][1,4]benzozaborane[2,3,4-kl]phenazaborane (abbreviated as: BBCz-Y), etc.

[0189] "Converting Triple Excitation Energy into Luminescent Materials" Next, as a luminescent material that can be used in the luminescent layer 113 to convert triple excitation energy into light emission, examples include phosphorescent materials (phosphorescent materials) or thermally activated delayed fluorescence (TADF) materials that exhibit thermally activated delayed fluorescence.

[0190] Phosphorescent materials are compounds that exhibit phosphorescence but not fluorescence at any temperature within a temperature range above low temperature (e.g., 77 K) and below room temperature (i.e., above 77 K and below 313 K). These phosphorescent materials preferably contain a metallic element with strong spin-orbit interactions, and organometallic complexes, metal complexes (platinum complexes), rare-earth metal complexes, etc., can be used. Specifically, it is preferable to contain transition metal elements, and particularly preferable to contain platinum group elements (ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), or platinum (Pt)). The inclusion of iridium increases the probability of direct transitions between the singlet ground state and the triplet excited state, and is therefore preferred.

[0191] Phosphorescent materials (wavelengths above 400nm and below 580nm: blue or green) Examples of phosphorescent substances that exhibit blue or green color and whose emission spectrum has a peak wavelength of 400 nm or more and less than 580 nm include the following substances.

[0192] For example, examples include: tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviated as: [Ir(mpptz-dmp)3]), and tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazol(triazolato))iridium(III) (abbreviated as: [Ir(Mptz)3] Organometallic complexes with a 4H-triazole ring, such as tri[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazole]iridium(III) (abbreviated as [Ir(iPrptz-3b)3]) and tri[3-(5-biphenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazole]iridium(III) (abbreviated as [Ir(iPr5btz)3]); tri[3-methyl-1- Organometallic complexes with a 1H-triazole ring, such as (2-methylphenyl)-5-phenyl-1H-1,2,4-triazole]iridium(III) (abbreviated as [Ir(Mptz1-mp)3]) and tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazole)iridium(III) (abbreviated as [Ir(Prptz1-Me)3]); fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl] [Ir(iPrpim)3]tri[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III)]tri[Ir(dmpimpt-Me)3]tri[2-{1-[2,6-bis(1-methylethyl)phenyl]-1H-imidazo-2-yl-κN] 3 Organometallic complexes with imidazole rings, such as}-4-cyanophenyl-κC)iridium(III) (abbreviated as CNImIr); tris[(6-tert-butyl-3-phenyl-2H-imidazo[4,5-b]pyrazin-1-yl-κC] 2 Organometallic complexes with a benzimidazole skeleton, such as phenyl-κC]iridium(III) (abbreviated as [Ir(cb)3]); and bis[2-(4',6'-difluorophenyl)pyridinium-N,C 2’ Iridium(III) tetrakis(1-pyrazolyl)borate (abbreviated as: FIr6), bis[2-(4',6'-difluorophenyl)pyridinium-N,C 2’ Iridium(III) pyridine carboxylate (abbreviated as FIRPIC), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinium-N,C 2’ Iridium(III)pyridinecarboxylate (abbreviated as: [Ir(CF3ppy)2(pic)]), bis[2-(4',6'-difluorophenyl)pyridinium-N,C 2’Organometallic complexes such as iridium(III) acetylacetone (abbreviated as: Fir(acac)) and phenylpyridine derivatives with electron-withdrawing groups as ligands, (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC 2 ]phenoxy-κC 2}-9-(4-tert-butyl-2-pyridyl-κN)carbazole-2,1-diyl-κC 1 Platinum(II) (abbreviated as PtON-TBBI) and other platinum complexes, etc. Alternatively, compounds containing a portion of the hydrogen atoms that are deuterium can also be used.

[0193] Phosphorescent materials (wavelength above 490nm and below 590nm: green or yellow) Examples of phosphorescent substances that exhibit green or yellow color and whose emission spectrum has a peak wavelength of 490 nm or higher but less than 590 nm include the following substances.

[0194] For example, examples include: tris(4-methyl-6-phenylpyrimidine)iridium(III) (abbreviated as [Ir(mppm)3]), tris(4-tert-butyl-6-phenylpyrimidine)iridium(III) (abbreviated as [Ir(tBuppm)3]), (acetylacetonate)bis(6-methyl-4-phenylpyrimidine)iridium(III) (abbreviated as [Ir(mppm)2(acac)]), (acetylacetonate)bis(6-tert-butyl-4-phenylpyrimidine)iridium(III) (abbreviated as [Ir(tBuppm)2(acac)]), (acetylacetonate)bis[6-(2-norborneol)-4-phenylpyrimidine]iridium(III) (abbreviated as [Ir(nbppm)2(acac)]), (acetylacetonate)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidine]iridium(III) (abbreviated as Ir(mpmppm)). Organometallic iridium complexes with pyrimidine rings, such as 2(acac)), (acetylacetonate)bis{4,6-dimethyl-2-[6-(2,6-dimethylphenyl)-4-pyrimidinyl-κN3]phenyl-κC}iridium(III) (abbreviated as: [Ir(dmppm-dmp)2(acac)]), (acetylacetonate)bis(4,6-diphenylpyrimidinyl)iridium(III) (abbreviated as: [Ir(dppm)2(acac)]); organometallic iridium complexes with pyrazine rings, such as (acetylacetonate)bis(3,5-dimethyl-2-phenylpyrazine)iridium(III) (abbreviated as: [Ir(mppr-Me)2(acac)]), (acetylacetonate)bis(5-isopropyl-3-methyl-2-phenylpyrazine)iridium(III) (abbreviated as: [Ir(mppr-iPr)2(acac)]); tri(2-phenylpyridinyl-N,C 2’Iridium(III) (abbreviated as: [Ir(ppy)3]), bis(2-phenylpyridinium-N,C) 2’ Iridium(III) acetylacetone (abbreviated as [Ir(ppy)2(acac)]), bis(benzo[h]quinoline)iridium(III) acetylacetone (abbreviated as [Ir(bzq)2(acac)]), tri(benzo[h]quinoline)iridium(III) (abbreviated as [Ir(bzq)3]), tri(2-phenylquinoline-N,C 2’ Iridium(III) (abbreviated as: [Ir(pq)3]), bis(2-phenylquinoline-N,C) 2’Iridium(III) acetylacetone (abbreviated as [Ir(pq)2(acac)]), bis[2-(2-pyridyl-κN)phenyl-κC][2-(4-phenyl-2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviated as [Ir(ppy)2(4dppy)]), bis[2-(2-pyridyl-κN)phenyl-κC][2-(4-methyl-5-phenyl-2-pyridyl-κN)phenyl-κC], [2-d3-methyl-8-(2-pyridyl-κN)benzofurano[2,3-b]pyridyl-κC]bis[2-(5-d3-methyl-2-pyridyl-κN2)phenyl-κC] Iridium (III) (abbreviated as: Ir(5mppy-d3)2(mbfpypy-d3)), {2-(methyl-d3)-8-[4-(1-methylethyl-1-d)-2-pyridyl-κN]benzofurano[2,3-b]pyridin-7-yl-κC}bis{5-(methyl-d3)-2-[5-(methyl-d3)2-pyridin-κN]phenyl-κC}Iridium (III) (abbreviated as: Ir(5mtpy-d6)2(mbfpypy-iPr-d4)), [2-(methyl-d3)-8-(2-pyridin-κN)benzofurano[2,3-b]pyridin-κC]bis[2-(2 [2-(4-methyl-5-phenyl-2-pyridyl-κN)phenyl-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviated as: Ir(ppy)2(mbfpypy-d3)), [2-(4-methyl-5-phenyl-2-pyridyl-κN)phenyl-κC]bis[2-(5-d3-methyl-2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviated as: Ir(ppy)2(mdppy)), [2-(4-d3-methyl-5-phenyl-2-pyridyl-κN2)phenyl-κC]bis[2-(5-d3-methyl-2-pyridyl-κN2)phenyl-κC]iridium(III) (abbreviated as: [Ir(5mppy-d3)2(mdppy-d3)]), [2- Organometallic iridium complexes with pyridine rings, such as methyl-8-(2-pyridyl-κN)benzofurano[2,3-b]pyridine-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviated as: [Ir(ppy)2(mbfpypy)]), tri{2-[5-(methyl-d3)4-phenyl-2-pyridyl-κ-d3]bis[2-(2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviated as: [Ir(ppy)2N]phenyl-κC}iridium(III) (abbreviated as: Ir(5m4dppy-d3)3), and bis(2,4-diphenyl-1,3-oxazol-N,C 2’ Iridium(III) acetylacetone (abbreviated as: [Ir(dpo)2(acac)]), bis{2-[4'-(perfluorophenyl)phenyl]pyridine-N,C 2’Iridium(III) acetylacetone (abbreviated as: [Ir(p-PF-ph)2(acac)]), bis(2-phenylbenzothiazole-N,C 2’ Organometallic complexes such as iridium(III) acetylacetone (abbreviated as [Ir(bt)2(acac)]); rare earth metal complexes such as tri(acetylacetone)(monophanyline)terbium(III) (abbreviated as [Tb(acac)3(Phen)]); platinum(II) (abbreviated as Pt(t)) Organometallic platinum complexes such as BudppymmtBubiz-tBubp), [2-(4-(3,5-di-tert-butylphenyl)-6-{3-[4-(5'-tert-butyl[1,1':3',1”-terphenyl]-2'-yl)-2-pyridyl-κN]phenyl-κC2}-2-pyridyl-κN)phenol-κO]platinum(II) (abbreviated as Pt(4tButpppypyp-mmtBup)) can also be used. Additionally, compounds containing hydrogen atoms that are partly deuterium can also be used.

[0195] Phosphorescent materials (wavelengths above 570nm and below 750nm: yellow or red) The following substances are examples of phosphorescent materials that exhibit yellow or red color and whose emission spectrum has a peak wavelength of 570 nm or higher and less than 750 nm.

[0196] For example, examples include (diisobutyrylmethane)bis[4,6-bis(3-methylphenyl)pyrimidinium]iridium(III) (abbreviated as: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinium](dineopentylmethane)iridium(III) (abbreviated as: [Ir(5mdppm)2(dpm)]), and (dineopentylmethane)bis[4,6-di(naphthyl-1-yl)pyrimidinium]iridium(III) (abbreviated as: [Ir(d1npm)2(dpm)]), etc. Organometallic complexes with pyrimidine rings; (acetylacetonate)bis(2,3,5-triphenylpyrazine)iridium(III) (abbreviation: [Ir(tppr)2(acac)]), bis(2,3,5-triphenylpyrazine)(dineopentylmethane)iridium(III) (abbreviation: [Ir(tppr)2(dpm)]), bis{4,6-dimethyl-2-[3-(3,5-dimethylphenyl)-5-phenyl-2-pyrazinyl-κN]phenyl-κC}(2,6-dimethyl-3,5-heptanedione-κC) 2O,O')iridium(III) (abbreviated as: [Ir(dmdppr-P)2(dibm)]), bis{4,6-dimethyl-2-[5-(4-cyano-2,6-dimethylphenyl)-3-(3,5-dimethylphenyl)-2-pyrazinyl-κN]phenyl-κC}(2,2,6,6-tetramethyl-3,5-heptanedione-κ 2 O,O')iridium(III) (abbreviated as: [Ir(dmdppr-dmCP)2(dpm)]), bis{2-[5-(2,6-dimethylphenyl)-3-(3,5-dimethylphenyl)-2-pyrazinyl-κN]-4,6-dimethylphenyl-κC}(2,2',6,6'-tetramethyl-3,5-heptanedione-κ) 2 O,O')iridium(III) (abbreviated as: [Ir(dmdppr-dmp)2(dpm)]),(acetylacetonate)bis(2-methyl-3-phenylquinoxalinato)]-N,C 2’ Iridium(III) (abbreviated as: [Ir(mpq)2(acac)]), (acetylacetonate)bis(2,3-diphenylquinoxalinato)-N,C 2’ Organometallic complexes with pyrazine rings, such as iridium(III) (abbreviated as [Ir(dpq)2(acac)]) and (acetylacetonate)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviated as [Ir(Fdpq)2(acac)]); tris(1-phenylisoquinoline-N,C 2’ Iridium(III) (abbreviated as: [Ir(piq)3]), bis(1-phenylisoquinoline-N,C) 2’ Iridium(III) acetylacetone (abbreviated as: [Ir(piq)2(acac)]) and bis[4,6-dimethyl-2-(2-quinolinyl-κN)phenyl-κC](2,4-pentanedione-κ) 2Organometallic complexes with pyridine rings, such as O,O')iridium(III) (abbreviated as: [Ir(dmpqn)2(acac)]), (3,7-diethyl-4,6-nonanedione-κO4,κO6)bis[2,4-dimethyl-6-[7-(1-methylethyl)-1-isoquinoline-κN]phenyl-κC]iridium(III), (3,7-diethyl-4,6-nonanedione-κO4,κO6)bis[2,4-dimethyl-6-[5-(1-methylethyl)-2-quinolinyl-κN]phenyl-κC]iridium(III). Platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (abbreviated as [PtOEP]); rare earth metal complexes such as tris(1,3-diphenyl-1,3-propanedionato) (monophanyline) europium(III) (abbreviated as [Eu(DBM)3(Phen)]) and tris[1-(2-thiophenecarboxyl)-3,3,3-trifluoroacetone] (monophanyline) europium(III) (abbreviated as [Eu(TTA)3(Phen)]). Additionally, compounds containing a portion of deuterium as hydrogen can also be used.

[0197] TADF Materials Furthermore, the following materials can be used as TADF materials. TADF materials refer to materials with a small energy difference between the S1 and T1 levels (preferably 0.20 eV or less) that can utilize minimal thermal energy to upconvert a triplet excited state into a singlet excited state (reverse intersystem crossing) and efficiently exhibit luminescence (fluorescence) from the singlet excited state. The conditions for efficiently obtaining thermally activated delayed fluorescence are as follows: the energy difference between the triplet and singlet excited levels is 0.00 eV or more and 0.20 eV or less, preferably 0.00 eV or more and 0.10 eV or less. The delayed fluorescence emitted by TADF materials refers to luminescence with the same spectrum as general fluorescence but with a very long lifetime. Its lifetime is 1 × 10⁻⁶. -6 seconds or more or 1×10 -3 seconds or more.

[0198] In addition, TADF materials can also be used as electron transport materials, hole transport materials, and host materials.

[0199] Examples of TADF materials include fullerenes and their derivatives, acridine derivatives such as pursanthin, and eosin. Additionally, examples include metalloporphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd). Examples of metalloporphyrins include protoporphyrin-tin fluoride complexes (SnF2(ProtoIX)), mesoporphyrin-tin fluoride complexes (SnF2(Meso IX)), hematoporphyrin-tin fluoride complexes (SnF2(Hemato IX)), tetramethyl coprophyrin-tin fluoride complexes (SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complexes (SnF2(OEP)), protoporphyrin-tin fluoride complexes (SnF2(Etio I)), and octaethylporphyrin-platinum chloride complexes (PtCl2OEP).

[0200] [Chemical Formula 4] In addition to the above, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazole-11-yl)-1,3,5-triazine (abbreviated as: PIC-TRZ), 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviated as: PCCzPTzn), 2-[4-(10H [-Phenoxazin-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-oxanthracene-9-one (abbreviation: ACRXTN), bis[4 -(9,9-dimethyl-9,10-dihydroacrylidine)phenyl]sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acrylidine-9,9'-anthraphen]-10'-one (abbreviation: ACRSA), 4-(9'-phenyl-[3,3'-bi-9H-carbazole]-9-yl)benzofurano[3,2-d]pyrimidine (abbreviation: 4PCCzBfpm), 4-[4-(9'-phenyl- [3,3'-bi-9H-carbazole]-9-yl)phenyl]benzofuran[3,2-d]pyrimidine (abbreviation: 4PCCzPBfpm), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), and other heteroaromatic compounds with π-electron-rich and π-electron-deficient forms.

[0201] Furthermore, in substances where π-electron-rich and π-electron-deficient heteroaromatic compounds are directly bonded, the π-electron-rich heteroaromatic compounds exhibit strong donor properties and the π-electron-deficient heteroaromatic compounds exhibit strong acceptor properties, resulting in a smaller energy difference between the singlet and triplet excited states, making them particularly preferred. Additionally, TADF materials in thermal equilibrium between the singlet and triplet excited states (TADF100) can also be used as TADF materials. Due to their short luminescence lifetime (excitation lifetime), these TADF materials can suppress efficiency degradation in the high-brightness regions of light-emitting devices.

[0202] [Chemical Formula 5] In addition to the above, nanostructures of transition metal compounds with a perovskite structure can be cited as materials capable of converting triple excitation energy into luminescence. Metal halide perovskite nanostructures are particularly preferred. Nanoparticles and nanorods are preferred as such nanostructures.

[0203] Furthermore, the light-emitting layer 113 can also be composed of two or more layers. For example, when the light-emitting layer 113 is formed by sequentially stacking a first light-emitting layer and a second light-emitting layer from the hole transport layer side, a material with hole transport properties can be used as the main material of the first light-emitting layer and a material with electron transport properties can be used as the main material of the second light-emitting layer. In addition, the light-emitting materials contained in the first and second light-emitting layers can be the same or different materials, and can be materials that emit light of the same color or materials that emit light of different colors. By using light-emitting materials that emit light of different colors in each of the two light-emitting layers, multiple light emission can be obtained simultaneously. In particular, it is preferable to select light-emitting materials for each light-emitting layer so that white light emission can be obtained by combining the light emitted by the two light-emitting layers.

[0204] In addition, the light-emitting layer 113 may also contain materials other than the host material 118 and the guest material 119.

[0205] In addition, the light-emitting layer 113 can be formed using methods such as vapor deposition (including vacuum vapor deposition), inkjet printing, coating, and gravure printing. Furthermore, besides the materials mentioned above, it may also contain inorganic compounds such as quantum dots or polymeric compounds (oligomers, dendritic polymers, polymers, etc.).

[0206] Hole Injection Layer The hole injection layer (111, 111a, 111b) is a layer in which holes are injected from the first electrode 101, which serves as the anode, and the charge generation layer (106, 106a, 106b) into the organic compound layer (103, 103a, 103b), and is a layer containing organic acceptor material and a material with high hole injection capability.

[0207] The hole injection layers (111, 111a, 111b) function to lower the injection barrier of holes from one of the pair of electrodes (first electrode 101 or second electrode 102) and promote hole injection. They are formed, for example, using transition metal oxides, phthalocyanine derivatives, or aromatic amines. Examples of transition metal oxides include molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide. Examples of phthalocyanine derivatives include phthalocyanine or metallic phthalocyanine. Examples of aromatic amines include benzidine derivatives or phenylene diamine derivatives. Furthermore, polymers such as polythiophene or polyaniline can also be used; typically, poly(ethyldioxythiophene) / polystyrene sulfonic acid is used as a self-doped polythiophene.

[0208] As hole injection layers (111, 111a, 111b), layers comprising a composite material consisting of a hole-transporting material and a material exhibiting electron-receptivity to the hole-transporting material can be used. Alternatively, a stack of layers containing electron-receptivity materials and layers containing hole-transporting materials can be used. Charge transfer and acceptance can occur between these materials in a stationary state or in the presence of an electric field. Examples of electron-receptivity materials include organic acceptors such as quinone dimethyl derivatives, chloroquinone derivatives, or hexaazatriphenylene derivatives. Specifically, compounds with electron-withdrawing groups (halogen or cyano groups) such as 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinone dimethyl (F4-TCNQ), chloroquinone, and 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HAT-CN) can be used. Furthermore, transition metal oxides, such as oxides of Group 4 to Group 8 metals, can also be used. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, rhenium oxide, etc., can be used. Molybdenum oxide is particularly preferred because it is stable in the atmosphere, has low hygroscopicity, and is easy to handle.

[0209] As a hole transport material, materials with higher hole transport than electron transport can be used, preferably those with a density of 1×10⁻⁶. -6 cm 2 Materials with a hole mobility of / Vs or higher can be used. Specifically, aromatic amines, carbazole derivatives, aromatic hydrocarbons, stilbene derivatives, etc., can be used as hole transport materials suitable for use in the light-emitting layer 113. The aforementioned hole transport materials can also be polymer compounds.

[0210] Hole transport layer The hole transport layers (112, 112a, 112b) are layers containing hole transport materials, and hole transport materials exemplified as those used in hole injection layers (111, 111a, 111b) can be used. The hole transport layers (112, 112a, 112b) have the function of transporting holes injected into the hole injection layers (111, 111a, 111b) to the light-emitting layers (113, 113a, 113b), so it is preferable that they have HOMO levels that are the same as or close to the HOMO levels of the hole injection layers (111, 111a, 111b).

[0211] Furthermore, the aforementioned hole transport material is preferably 1×10 -6 cm 2 Materials with a hole mobility of / Vs or higher. However, any material other than those described above can be used as long as its hole transport capacity is higher than its electron transport capacity. Furthermore, the layer containing the material with high hole transport capacity is not limited to a single layer, but can also be a layer composed of two or more layers of the above-mentioned materials.

[0212] Electron transport layer The electron transport layers (114, 114a, 114b) function to transport electrons injected from one of the two electrodes (first electrode 101 or second electrode 102) through the electron injection layers (115, 115a, 115b) to the light-emitting layer 113. As the electron transport material, a material with higher electron transport than hole transport can be used, preferably one with a electron transport capacity of 1×10⁻⁶. -6 cm 2 Materials with an electron mobility of 1 × 10⁻⁶ Vs or higher. Compounds that readily accept electrons (materials with electron transport properties) can be used, such as nitrogen-containing heteroaromatic compounds or metal complexes with a π-electron-deficient heteroaromatic ring skeleton. Specifically, examples of metal complexes containing quinoline ligands, benzoquinoline ligands, oxazole ligands, or thiazole ligands that can be used as electron transport materials for the luminescent layer 113 include those containing quinoline ligands, benzoquinoline ligands, oxazole ligands, or thiazole ligands. Furthermore, examples include oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, phenanthroline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and triazine derivatives. Moreover, the aforementioned electron transport materials preferably have an electron mobility of 1 × 10⁻⁶ Vs. -6 cm 2 Materials with an electron mobility of / Vs or higher. Any material whose electron transport is higher than its hole transport can be used as an electron transport layer. Furthermore, the electron transport layer (114, 114a, 114b) is not limited to a single layer, but can also be a layer composed of two or more of the above materials.

[0213] Furthermore, a layer for controlling the movement of electron carriers can be placed between the electron transport layer (114, 114a, 114b) and the light-emitting layer (113, 113a, 113b). This layer is formed by adding a small amount of a substance with high electron trapping properties to the aforementioned material with high electron transport properties. By suppressing the movement of electron carriers, the balance of carriers can be adjusted. This structure is very effective in suppressing problems caused by electrons passing through the light-emitting layer (such as a decrease in device lifetime).

[0214] Electron Injection Layer The electron injection layers (115, 115a, 115b) function to lower the injection barrier of electrons from the second electrode 102 and promote electron injection. For example, group 1 metals, group 2 metals, or their oxides, halides, carbonates, etc., can be used. Alternatively, composite materials of the aforementioned electron transport materials and materials exhibiting electron-donating properties can be used. Examples of electron-donating materials include group 1 metals, group 2 metals, or their oxides. Specifically, lithium fluoride (LiF), sodium fluoride (NaF), cesium fluoride (CsF), calcium fluoride (CaF2), and lithium oxide (LiO) can be used. x Alkali metals, alkaline earth metals, or compounds of these metals can be used. Additionally, rare earth metal compounds such as erbium fluoride (ErF3) can be used. Furthermore, electron salts can be used in the electron injection layer 115. Examples of such electron salts include substances that add electrons at high concentrations to a mixed oxide of calcium and aluminum. Furthermore, substances suitable for electron transport layers (114, 114a, 114b) can also be used in the electron injection layers (115, 115a, 115b).

[0215] Alternatively, a composite material formed by mixing an organic compound with an electron donor can be used for the electron injection layer (115, 115a, 115b). This composite material exhibits good electron injection and electron transport properties because electrons are generated in the organic compound through the electron donor. In this case, the organic compound is preferably a material with good performance in transporting the generated electrons. Specifically, for example, the material constituting the electron transport layer 114 of the positive-type light-emitting device described above (metal complex or heteroaromatic compound, etc.) can be used. As the electron donor, any material that provides electrons to the organic compound is acceptable. Specifically, alkali metals, alkaline earth metals, or rare earth metals are preferred, such as lithium, sodium, cesium, magnesium, calcium, erbium, and ytterbium. Furthermore, alkali metal oxides or alkaline earth metal oxides are preferred, such as lithium oxide, calcium oxide, and barium oxide. Additionally, Lewis bases such as magnesium oxide can also be used. Furthermore, organic compounds such as tetrathiofulvalene (TTF) can also be used.

[0216] Alternatively, materials with strong alkalinity can be used for the electron injection layer (115, 115a, 115b). As a strongly basic material, specifically, organic compounds such as 1-(9,9'-spirobis[9H-fluorene]-2-yl)-1,3,4,6,7,8-hexahydro-2H-pyrimidino[1,2-a]pyrimidine (abbreviated as: 2hppSF), 2,9-bis(1,3,4,6,7,8-hexahydro-2H-pyrimidino[1,2-a]pyrimidin-1-yl)-1,10-phenanthroline (abbreviated as: 2,9hpp2Phen), 4,7-di-1-pyrrolidinyl-1,10-phenanthroline (abbreviated as: Pyrrd-Phen), or 8,8'-pyridinyl-2,6-diyl-bis(5,6,7,8-tetrahydroimidazo[1,2-a]pyrimidine) (abbreviated as: 2,6tip2Py) can be used.

[0217] Furthermore, the aforementioned light-emitting layer is preferably formed by vapor deposition (including vacuum vapor deposition). Additionally, the hole injection layer, hole transport layer, electron transport layer, and electron injection layer can be formed by methods such as vapor deposition (including vacuum vapor deposition), inkjet printing, coating, and gravure printing. Moreover, in addition to the materials mentioned above, inorganic compounds such as quantum dots or polymeric compounds (oligomers, dendritic polymers, polymers, etc.) can also be used as the aforementioned light-emitting layer, hole injection layer, hole transport layer, electron transport layer, and electron injection layer.

[0218] In addition, as quantum dots, colloidal quantum dots, alloy quantum dots, core-shell quantum dots, and nucleated quantum dots can be used. Furthermore, quantum dots containing elements from Groups 2 and 16, 13 and 15, 13 and 17, 11 and 17, or 14 and 15 can also be used. Alternatively, quantum dots containing elements such as cadmium (Cd), selenium (Se), zinc (Zn), sulfur (S), phosphorus (P), indium (In), tellurium (Te), lead (Pb), gallium (Ga), arsenic (As), and aluminum (Al) can be used.

[0219] A pair of electrodes The first electrode 101 and the second electrode 102 are used as the anode or cathode of the light-emitting device. The first electrode 101 and the second electrode 102 can be formed using metals, alloys, conductive compounds, mixtures thereof, or laminates thereof.

[0220] One of the first electrode 101 and the second electrode 102 is preferably formed of a conductive material that has the function of reflecting light. Examples of such conductive material include aluminum (Al) or alloys containing Al. Examples of alloys containing Al include alloys containing Al and L (L represents one or more of titanium (Ti), neodymium (Nd), nickel (Ni), and lanthanum (La), such as alloys containing Al and Ti or alloys containing Al, Ni, and La. Aluminum has low resistivity and high light reflectivity. In addition, since aluminum is abundant in the Earth's crust and inexpensive, the manufacturing cost of the light-emitting device can be reduced by using aluminum. Alternatively, silver (Ag) or alloys containing Ag and N (N represents one or more of yttrium (Y), Nd, magnesium (Mg), ytterbium (Yb), Al, Ti, gallium (Ga), zinc (Zn), indium (In), tungsten (W), manganese (Mn), tin (Sn), iron (Fe), Ni, copper (Cu), palladium (Pd), iridium (Ir), and gold (Au)) can also be used. Examples of silver-containing alloys include: alloys containing silver, palladium, and copper; alloys containing silver and copper; alloys containing silver and magnesium; alloys containing silver and nickel; alloys containing silver and gold; and alloys containing silver and ytterbium. In addition to the above materials, transition metals such as tungsten, chromium (or), molybdenum (Mo), copper, and titanium can be used.

[0221] Furthermore, light obtained from the light-emitting layer is extracted through one or both of the first electrode 101 and the second electrode 102. Therefore, at least one of the first electrode 101 and the second electrode 102 is preferably formed of a conductive material that allows light to pass through. Examples of such conductive material include a visible light transmittance of 40% or more and 100% or less, preferably 60% or more and 100% or less, and a resistivity of 1 × 10⁻⁶. -2 Conductive materials with an Ω·cm or lower conductivity.

[0222] Furthermore, the first electrode 101 and the second electrode 102 may also be formed of a conductive material that has the function of allowing light to pass through and reflecting light. Examples of such conductive materials include those with a visible light reflectance of 20% or more and 80% or less, preferably 40% or more and 70% or less, and a resistivity of 1×10⁻⁶. -2Conductive materials with a thickness of less than Ω·cm. For example, one or more of conductive metals, alloys, and conductive compounds can be used. Specifically, indium tin oxide (ITO), indium tin oxide containing silicon or silicon oxide (ITSO), indium zinc oxide, indium tin oxide containing titanium, indium titanium oxide, indium oxide containing tungsten oxide and zinc oxide, and other metal oxides can be used. In addition, metal thin films with a thickness of at least 1 nm and less than 30 nm can be used. As metals, for example, Ag or alloys of Ag and Al, Ag and Mg, Ag and Au, and Ag and Yb can be used.

[0223] Note that in this specification, etc., as the material having the function of allowing light to pass through, any material that has the function of allowing visible light to pass through and is conductive can be used, such as oxide conductors represented by ITO, oxide semiconductors, or organic conductors containing organic matter. Examples of organic conductors containing organic matter include composite materials formed by mixing organic compounds with electron donors, and composite materials formed by mixing organic compounds with electron acceptors. In addition, inorganic carbon materials such as graphene can also be used. Furthermore, the resistivity of this material is preferably 1 × 10⁻⁶. 5 Ω·cm or less, more preferably 1×10 4 Below Ω·cm.

[0224] Alternatively, one or both of the first electrode 101 and the second electrode 102 can be formed by stacking multiple of the above materials.

[0225] To improve light extraction efficiency, a material with a higher refractive index than an electrode that allows light to pass through can be formed in contact with the electrode. This material can be either conductive or non-conductive, as long as it allows visible light to pass through. Examples include oxide conductors, oxide semiconductors, and organic materials. Examples of organic materials include those exemplified as light-emitting layers, hole injection layers, hole transport layers, electron transport layers, or electron injection layers. Furthermore, inorganic carbon materials or metal thin films with a thickness sufficient to allow light to pass through can also be used, and multiple layers with thicknesses ranging from a few nm to tens of nm can be stacked.

[0226] When the first electrode 101 or the second electrode 102 is used as a cathode, a material with a low work function (3.8 eV or less) is preferably used. For example, elements belonging to Group 1 or Group 2 of the periodic table (e.g., alkali metals such as lithium, sodium, and cesium, alkaline earth metals such as calcium or strontium, magnesium, etc.), alloys containing the above elements (e.g., Ag and Mg or Al and Li), rare earth metals such as europium (Eu) or Yb, alloys containing the above rare earth metals, alloys containing aluminum, silver, etc., can be used.

[0227] When the first electrode 101 or the second electrode 102 is used as the anode, a material with a large work function (above 4.0 eV) is preferably used.

[0228] The first electrode 101 and the second electrode 102 can also be a laminate of conductive materials that reflect light and conductive materials that allow light to pass through. In this case, the first electrode 101 and the second electrode 102 can have the function of adjusting the optical distance so that the light from each light-emitting layer resonates at the desired wavelength and enhances its wavelength, which is preferred.

[0229] As for the deposition method of the first electrode 101 and the second electrode 102, sputtering, vapor deposition, printing, coating, MBE (Molecular Beam Epitaxy), CVD (Chemical Vapor Deposition), pulsed laser deposition, atomic layer deposition (ALD), etc. can be appropriately utilized.

[0230] Charge Generation Layer The charge generation layer 106 functions to inject electrons into the organic compound layer 103a and holes into the organic compound layer 103b when a voltage is applied between the first electrode 101 (anode) and the second electrode 102 (cathode). The charge generation layer 106 can have either a structure that adds an electron acceptor to the hole transport material (also called a P-type layer) or a structure that adds an electron donor to the electron transport material (also called an electron injection buffer layer). Alternatively, both structures can be stacked. Furthermore, an electron relay layer can be provided between the P-type layer and the electron injection buffer layer. Note that by using the above-described materials to form the charge generation layer 106, the increase in driving voltage caused by the stacking of organic compound layers can be suppressed.

[0231] When the charge generation layer 106 has a structure (P-type layer) that adds an electron acceptor to the hole transport material of the organic compound, the material shown in this embodiment can be used as the hole transport material. Furthermore, examples of electron acceptors include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinone dimethane (abbreviated as F4-TCNQ), chloroquinone, etc. Additionally, oxides of metals belonging to Groups 4 to 8 of the periodic table can be used. Specifically, examples include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, rhenium oxide, etc. Furthermore, the above-mentioned acceptor materials can also be used. Furthermore, a hybrid film formed by mixing the materials constituting the P-type layer can be used, or a single film containing each material can be stacked.

[0232] When the charge generation layer 106 has a structure (electron injection buffer layer) for adding an electron donor to the electron transport material, the material shown in this embodiment can be used as the electron transport material. Furthermore, alkali metals, alkaline earth metals, rare earth metals, metals belonging to Groups 2 and 13 of the periodic table, and their oxides or carbonates can be used as electron donors. Specifically, lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium oxide (Li₂O), cesium carbonate, etc., are preferred. In addition, organic compounds such as tetrathianaphthacene can also be used as electron donors.

[0233] In the charge generation layer 106, when an electron relay layer is provided between the p-type layer and the electron injection buffer layer, the electron relay layer at least contains a material with electron transport properties and has the function of smoothly transferring electrons while preventing the interaction between the electron injection buffer layer and the p-type layer. The LUMO energy level of the electron-transporting material contained in the electron relay layer is preferably located between the LUMO energy level of the acceptor material in the p-type layer and the LUMO energy level of the electron-transporting material contained in the electron transport layer in contact with the charge generation layer 106. Specifically, the LUMO energy level of the electron-transporting material in the electron relay layer is preferably -5.0 eV or higher, more preferably -5.0 eV or higher and -3.0 eV or lower. Furthermore, phthalocyanine materials or metal complexes having metal-oxygen bonds and aromatic ligands are preferably used as the electron-transporting material in the electron relay layer.

[0234] In addition, although Figure 6D The diagram shows a structure with two stacked organic compound layers 103, but a stacked structure with more than three organic compound layers can also be used by setting a charge generation layer between different organic compound layers.

[0235] Covering Layer Note that, although in Figures 6A to 6EAlthough not shown in the diagram, a capping layer can also be provided on the second electrode 102 of the light-emitting device. For example, a material with a high refractive index can be used for the capping layer. By providing a capping layer on the second electrode 102, the extraction efficiency of light emitted from the second electrode 102 can be improved.

[0236] Specific examples of materials that can be used for coatings include 5,5'-diphenyl-2,2'-di-5H-[1]benzothiopheno[3,2-c]carbazole (abbreviated as BisBTc), 4,4',4”-(benzyl-1,3,5-triyl)tris(dibenzothiophene) (abbreviated as DBT3P-II), etc.

[0237] Substrate Furthermore, the light-emitting device according to one aspect of the present invention can be manufactured on a substrate made of glass, plastic, or the like. As for the stacking order on the substrate, it can be stacked sequentially from either the first electrode 101 side or the second electrode 102 side.

[0238] Furthermore, as a substrate for forming the light-emitting device according to one embodiment of the present invention, materials such as glass, quartz, or plastic can be used. Alternatively, a flexible substrate can also be used. A flexible substrate is a flexible substrate that can be bent, such as a plastic substrate made of materials such as polycarbonate or polyarylate. Additionally, thin films or inorganic vapor-deposited thin films can be used. Note that other materials can be used as long as they function as a support in the manufacturing process of the light-emitting device and optical elements. Alternatively, any material that functions to protect the light-emitting device and optical elements is acceptable.

[0239] For example, various substrates can be used to form light-emitting devices in this specification. There are no particular limitations on the type of substrate. Examples of substrates include semiconductor substrates (e.g., single-crystal substrates or silicon substrates), SOI substrates, glass substrates, quartz substrates, plastic substrates, metal substrates, stainless steel substrates, substrates with stainless steel foil, tungsten substrates, substrates with tungsten foil, flexible substrates, laminated films, cellulose nanofibers (CNF) containing fibrous materials, paper, or substrate films. Examples of glass substrates include barium borosilicate glass, aluminoborosilicate glass, and soda-lime glass. Examples of flexible substrates, laminated films, and substrate films include plastics such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), and polytetrafluoroethylene (PTFE). Alternatively, acrylic resins can be used as examples. Alternatively, polypropylene, polyester, ethylene fluoride, or polyvinyl chloride can be used as examples. Alternatively, examples could include resins such as polyamide resins, polyimide resins, aromatic polyamide resins, or epoxy resins, inorganic vapor-deposited films, or paper.

[0240] Alternatively, a flexible substrate can be used as the substrate, and the light-emitting device can be directly formed on the flexible substrate. Alternatively, a release layer can be provided between the substrate and the light-emitting device. A release layer can be used when part or all of the light-emitting device is fabricated on the release layer, and then it is separated from the substrate and transferred to another substrate. In this case, the light-emitting device can also be transferred to a substrate with low heat resistance or a flexible substrate. Furthermore, as the aforementioned release layer, for example, a stacked structure of inorganic films such as tungsten films and silicon oxide films, or a structure in which a resin film such as polyimide is formed on the substrate can be used.

[0241] In other words, a light-emitting device is formed on one substrate and then transferred to another substrate, thereby allowing the light-emitting device to be disposed on the other substrate. Examples of substrates for which the light-emitting device is transferred, besides those mentioned above, include cellophane substrates, stone substrates, wood substrates, cloth substrates (including natural fibers (silk, cotton, linen), synthetic fibers (nylon, polyurethane, polyester), or recycled fibers (acetate fiber, cupro fiber, rayon, recycled polyester), leather substrates, and rubber substrates. By using these substrates, it is possible to manufacture light-emitting devices that are not easily damaged, have high heat resistance, are lightweight, or are thin.

[0242] Alternatively, a field-effect transistor (FET) can be formed on the aforementioned substrate, and a light-emitting device can be fabricated on an electrode electrically connected to the FET. This allows for the fabrication of an active matrix display device in which the driving of the light-emitting device is controlled by the FET.

[0243] Therefore, the structure shown in this embodiment can be appropriately combined with the structures shown in other embodiments.

[0244] Implementation Method 3 like Figure 7B As shown, a plurality of light-emitting devices 130 are formed on an insulating layer 175 to constitute a display device. In this embodiment, a display device according to one aspect of the present invention will be described in detail.

[0245] The display device 100 includes a pixel section 177 in which a plurality of pixels 178 are arranged in a matrix. The pixels 178 include sub-pixels 110R, 110G, and 110B.

[0246] In this specification, etc., the term "subpixel 110" is sometimes used to describe the common content among subpixels 110R, 110G, and 110B. Regarding other constituent elements distinguished by letters, symbols omitting the letters are sometimes used to indicate the common content among these constituent elements.

[0247] Subpixel 110R emits red light, subpixel 110G emits green light, and subpixel 110B emits blue light. Thus, an image can be displayed on pixel unit 177. Note that in this embodiment, only subpixels of three colors—red (R), green (G), and blue (B)—are used as an example for explanation; other colors of subpixels can also be combined. Furthermore, the number of subpixels is not limited to three; it can be four or more. Examples of four subpixels include: subpixels of four colors—R, G, B, and white (W); subpixels of four colors—R, G, B, and yellow (Y); and subpixels of four colors—R, G, B, and infrared (IR); etc.

[0248] In this specification, the row direction is sometimes referred to as the X direction and the column direction as the Y direction. The X direction and the Y direction intersect, for example, perpendicularly.

[0249] exist Figure 7A In the example shown, subpixels of different colors are arranged in the X direction, and subpixels of the same color are arranged in the Y direction. Note that subpixels of different colors can also be arranged in the Y direction, and subpixels of the same color can also be arranged in the X direction.

[0250] A connecting portion 140 may be provided on the outer side of the pixel portion 177, and a region 141 may also be provided thereon. The region 141 is provided between the pixel portion 177 and the connecting portion 140. An organic compound layer 103 is provided in the region 141. In addition, a conductive layer 151C is provided in the connecting portion 140.

[0251] exist Figure 7A In the example shown, region 141 and connecting portion 140 are located to the right of pixel portion 177, but there are no particular restrictions on the position of region 141 and connecting portion 140. Furthermore, region 141 and connecting portion 140 may be one or more.

[0252] Figure 7B It is along Figure 7A An example of a cross-sectional view of the dashed-dot line A1-A2 in the diagram. For example... Figure 7A As shown, the display device 100 includes an insulating layer 171, a conductive layer 172 on the insulating layer 171, an insulating layer 173 on the insulating layer 171 and the conductive layer 172, an insulating layer 174 on the insulating layer 173, and an insulating layer 175 on the insulating layer 174. The insulating layer 171 is disposed on a substrate (not shown). The insulating layers 175, 174, and 173 are provided with openings leading to the conductive layer 172, and a plug 176 is disposed such that it is inserted into the openings.

[0253] In the pixel section 177, a light-emitting device 130 is disposed on the insulating layer 175 and the plug 176. Furthermore, a protective layer 135 is disposed to cover the light-emitting device 130. A substrate 120 is bonded to the protective layer 135 by a resin layer 122. Additionally, it is preferable to provide an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 between adjacent light-emitting devices 130.

[0254] Figure 7B Cross-sections of multiple inorganic insulating layers 125 and multiple insulating layers 127 are shown, but when viewed from above the display device 100, the inorganic insulating layers 125 and insulating layers 127 are preferably formed as continuous layers. In other words, the inorganic insulating layers 125 and insulating layers 127 are preferably insulating layers having openings on the first electrode.

[0255] Figure 7B Light-emitting devices 130R, 130G, and 130B are shown as light-emitting device 130. Light-emitting devices 130R, 130G, and 130B emit light of different colors from each other. For example, light-emitting device 130R may emit red light, light-emitting device 130G may emit green light, and light-emitting device 130B may emit blue light. Alternatively, light-emitting devices 130R, 130G, or 130B may also emit other visible or infrared light.

[0256] One aspect of the display device of the present invention may include a top-emitting structure (top-emitting structure) that emits light in a direction opposite to that of the substrate on which the light-emitting device is formed. Alternatively, another aspect of the display device of the present invention may include a bottom-emitting structure (bottom-emitting structure).

[0257] Examples of luminescent materials contained in the light-emitting device 130 include organic compounds or organometallic complexes such as substances that emit fluorescence (fluorescent materials), substances that emit phosphorescence (phosphorescent materials), and substances that exhibit thermally activated delayed fluorescence (TADF) materials. Alternatively, inorganic compounds such as quantum dots may also be used.

[0258] The light-emitting device 130R has the structure shown in Embodiment 1. The light-emitting device 130R includes a first electrode (pixel electrode) composed of conductive layers 151R and 152R, an organic compound layer 103R on the first electrode, a common layer 104 on the organic compound layer 103R, and a common electrode 155 on the common layer 104. Furthermore, the common electrode 155 corresponds to the second electrode 102 in Embodiments 1 and 2. The common layer 104 may or may not be provided, but its presence reduces damage to the organic compound layer 103R during processing, making it preferred. When the common layer 104 is provided, it is preferably an electron injection layer. In the absence of the common layer 104, the organic compound layer 103R corresponds to the organic compound layer 103 in Embodiments 1 and 2. When the common layer 104 is provided, the stacked structure of the organic compound layer 103R and the common layer 104 corresponds to the organic compound layer 103 in Embodiments 1 and 2.

[0259] The light-emitting device 130G has the structure shown in Embodiment 1. The light-emitting device 130G includes a first electrode (pixel electrode) composed of conductive layers 151G and 152G, an organic compound layer 103G on the first electrode, a common layer 104 on the organic compound layer 103G, and a common electrode 155 on the common layer 104. Furthermore, the common electrode 155 corresponds to the second electrode 102 in Embodiments 1 and 2. The common layer 104 may or may not be provided, but its presence reduces damage to the organic compound layer 103G during processing, making it preferred. In the absence of the common layer 104, the organic compound layer 103G corresponds to the organic compound layer 103 in Embodiments 1 and 2. When the common layer 104 is provided, the stacked structure of the organic compound layer 103G and the common layer 104 corresponds to the organic compound layer 103 in Embodiments 1 and 2.

[0260] The light-emitting device 130B has the structure shown in Embodiment 1. The light-emitting device 130B includes a first electrode (pixel electrode) composed of conductive layers 151B and 152B, an organic compound layer 103B on the first electrode, a common layer 104 on the organic compound layer 103B, and a common electrode 155 on the common layer 104. Furthermore, the common electrode 155 corresponds to the second electrode 102 in Embodiments 1 and 2. The common layer 104 may or may not be provided, but its presence reduces damage to the organic compound layer 103B during processing, making it preferred. In the absence of the common layer 104, the organic compound layer 103B corresponds to the organic compound layer 103 in Embodiments 1 and 2. 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.

[0261] In a light-emitting device, one of the pixel electrode and the common electrode is used as the anode, and the other is used as the cathode. Unless otherwise specified, the following description assumes that the pixel electrode is used as the anode and the common electrode is used as the cathode.

[0262] Organic compound layers 103R, 103G, and 103B are arranged independently in an island-like pattern according to each light-emitting device or each light-emitting color. By arranging the organic compound layers 103 in an island-like pattern according to each light-emitting device 130, leakage current between adjacent light-emitting devices 130 can be suppressed even in high-definition display devices. This prevents crosstalk and enables a display device with extremely high contrast. In particular, it enables a display device with high current efficiency at low brightness.

[0263] An island-shaped organic compound layer 103 is formed by depositing an EL film and processing the EL film using photolithography.

[0264] Furthermore, in one aspect of the display device of the present invention, the first electrode (pixel electrode) of the light-emitting device preferably has a stacked structure. For example, in Figure 7BIn the example shown, the first electrode of the light-emitting device 130 has a stacked structure of conductive layers 151 (151R, 151G, 151B) and conductive layers 152 (152R, 152G, 152B). For example, when the display device 100 has a top-emitting structure and the pixel electrode of the light-emitting device 130 is used as the anode, the conductive layer 151 is preferably a layer with high visible light reflectivity, and the conductive layer 152 is preferably a layer with, for example, visible light transmittance and a large work function. When the display device 100 has a top-emitting structure, the higher the visible light reflectivity of the pixel electrode, the higher the extraction efficiency of the light emitted by the organic compound layer 103. In addition, when the pixel electrode is used as the anode, the larger the work function of the pixel electrode, the easier it is to inject holes into the organic compound layer 103. Thus, by having a stacked structure of a conductive layer 151 with high visible light reflectivity and a conductive layer 152 with a large work function in the pixel electrode of the light-emitting device 130, the light-emitting device 130 can be a light-emitting device with high light extraction efficiency and low driving voltage. Note that in this specification, when describing the common elements among conductive layers 151R, 151G, and 151B, they are sometimes referred to as conductive layer 151.

[0265] When the conductive layer 151 is a layer with high visible light reflectivity, the visible light reflectivity of the conductive layer 151 is preferably, for example, 40% or more and 100% or less, or 70% or more and 100% or less. Furthermore, when the conductive layer 152 is an electrode with visible light transmittance, the visible light transmittance is preferably, for example, 40% or more.

[0266] In cases where the pixel electrode has a multi-layered stacked structure, the pixel electrode may sometimes deteriorate due to reactions between these layers. For example, when removing the film formed after the pixel electrode is formed by wet etching, galvanic corrosion may occur due to the contact of the chemical solution with the pixel electrode.

[0267] Therefore, in the display device 100 of this embodiment, insulating layers 156 (156R, 156G, 156B) are formed on the sides of conductive layers 151 and 152. This prevents the contact of the chemical solution with the conductive layer 151, for example, when the film formed after the pixel electrode including conductive layers 151 and 152 is removed by wet etching. Thus, galvanic corrosion in the pixel electrode can be suppressed, for example. Therefore, the display device 100 can be manufactured using a high-yield method, resulting in an inexpensive display device. Furthermore, defects in the display device 100 can be suppressed, making it a highly reliable display device. Note that in this specification, when describing the common elements among insulating layers 156R, 156G, and 156B, they are sometimes referred to as insulating layer 156.

[0268] As the conductive layer 151, a metallic material can be used, for example. 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), neodymium (Nd), and alloys thereof can also be used.

[0269] As the conductive layer 152, an oxide containing one or more of indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used. For example, conductive oxides containing one or more of indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, gallium-containing zinc oxide, titanium oxide, gallium-containing indium zinc oxide, aluminum-containing indium zinc oxide, silicon-containing indium tin oxide, and silicon-containing indium zinc oxide are preferred. In particular, silicon-containing indium tin oxide has a large work function, for example, 4.0 eV or more, so it is suitable for use as the conductive layer 152.

[0270] Conductive layer 151 and conductive layer 152 may each have a stacked structure containing multiple layers of different materials. In this case, conductive layer 151 may also include a layer using a material that can be used in conductive layer 152, such as a conductive oxide, and conductive layer 152 may also include a layer using a material that can be used in conductive layer 151, such as a metallic material. For example, when conductive layer 151 has a stacked structure of two or more layers, the layer in contact with conductive layer 152 may be a layer using a material that can be used in conductive layer 152.

[0271] The structure of this embodiment can be appropriately combined with the structures of other embodiments.

[0272] Implementation Method 4 In this embodiment, refer to Figures 8A to 8G as well as Figures 9A to 9I This invention describes a light-emitting device according to one aspect of the present invention.

[0273] [Pixel layout] In this embodiment, the main description is related to Figure 7A Different pixel layouts. There are no particular restrictions on the arrangement of subpixels; various arrangements can be used. Examples of subpixel arrangements include stripe arrangements, S-stripes, matrix arrangements, Delta arrangements, Bayer arrangements, and Pentile arrangements.

[0274] In this embodiment, the top surface shape of the sub-pixel shown in the accompanying drawings corresponds to the top surface shape of the light-emitting region.

[0275] In addition, the top surface shape of a sub-pixel can be, for example, a triangle, a quadrilateral (including a rectangle and a square), a pentagon or other polygon, the aforementioned polygonal shapes with rounded corners, an ellipse or a circle, etc.

[0276] Furthermore, the circuit layout constituting the sub-pixel is not limited to the range of the sub-pixel shown in the attached figure, and can also be arranged outside of it.

[0277] Figure 8A The pixel 178 shown is arranged in an S-stripes pattern. Figure 8A The pixel 178 shown is composed of three sub-pixels: sub-pixel 110R, sub-pixel 110G, and sub-pixel 110B.

[0278] Figure 8B The pixel 178 shown includes sub-pixels 110R, 110G, 110B, and 110B, each with a rounded corner, forming a top surface that is approximately trapezoidal or triangular. Furthermore, the light-emitting area of ​​sub-pixels 110R is larger than that of sub-pixels 110G. Thus, the shape and size of each sub-pixel can be determined independently. For example, the size of a sub-pixel including a highly reliable light-emitting device can be smaller.

[0279] Figure 8C Pixels 124a and 124b shown are arranged in a Pentile pattern. Figure 8C In the example shown, pixel 124a, which includes sub-pixels 110R and 110G, and pixel 124b, which includes sub-pixels 110G and 110B, are alternately configured.

[0280] Figures 8D to 8F Pixels 124a and 124b are arranged in a Delta pattern. Pixel 124a includes two sub-pixels (sub-pixels 110R and 110G) in the top row (first row) and one sub-pixel (sub-pixel 110B) in the bottom row (second row). Pixel 124b includes one sub-pixel (sub-pixel 110B) in the top row (first row) and two sub-pixels (sub-pixels 110R and 110G) in the bottom row (second row).

[0281] Figure 8D This example shows an example where each sub-pixel has a top surface shape that is approximately quadrilateral with rounded corners. Figure 8E This shows an example where each sub-pixel has a circular top surface shape. Figure 8F This example shows an example where each sub-pixel has an approximately hexagonal top surface shape with rounded corners.

[0282] exist Figure 8FIn this configuration, each subpixel is arranged inside a closely spaced hexagonal region. Each subpixel is arranged such that it is surrounded by six subpixels when focusing on one of them. Furthermore, subpixels that emit light of the same color are arranged so that they are not adjacent to each other. For example, each subpixel is arranged such that three subpixels 110G and three subpixels 110B are arranged alternately around subpixel 110R when focusing on it.

[0283] Figure 8G An example is shown where the subpixels of each color are configured in a zigzag shape. Specifically, when viewed from above, the upper positions of two subpixels arranged in the row direction (e.g., subpixel 110R and subpixel 110G or subpixel 110G and subpixel 110B) are offset.

[0284] exist Figures 8A to 8G Of the pixels shown, for example, it is preferable to set subpixel 110R as subpixel R that emits red light, subpixel 110G as subpixel G that emits green light, and subpixel 110B as subpixel B that emits blue light. Note that the structure of the subpixels is not limited to this, and the color emitted by the subpixels and their arrangement order can be appropriately determined. For example, subpixel 110G can also be set as subpixel R that emits red light, and subpixel 110R can be set as subpixel G that emits green light.

[0285] In photolithography, the finer the pattern, the more significant the effect of light diffraction becomes. Therefore, when transferring the photomask pattern through exposure, the fidelity deteriorates, making it difficult to process the resist mask into the desired shape. Consequently, even if the photomask pattern is rectangular, it is easy to form a pattern with rounded corners. Thus, the top surface shape of a subpixel sometimes takes the form of a polygon with rounded corners, an ellipse, or a circle.

[0286] Furthermore, in one embodiment of the manufacturing method of the light-emitting device of the present invention, an organic compound layer is processed into an island shape using a photoresist mask. The photoresist film formed on the organic compound layer needs to be cured at a temperature lower than the heat resistance temperature of the organic compound layer. Therefore, depending on the heat resistance temperature of the organic compound layer material and the curing temperature of the photoresist material, the curing of the photoresist film is sometimes insufficient. The insufficiently cured photoresist film sometimes takes on a shape far from the desired shape during processing. As a result, the top surface shape of the organic compound layer is sometimes a polygonal shape with rounded corners, an ellipse, or a circle, etc. For example, when a photoresist mask with a square top surface shape is to be formed, sometimes a photoresist mask with a circular top surface shape is formed, and the top surface shape of the organic compound layer is circular.

[0287] To ensure the top surface of the organic compound layer has the desired shape, a technique called OPC (Optical Proximity Correction) can be used to pre-correct the mask pattern in a manner that aligns the design pattern with the transfer pattern. Specifically, in OPC, for example, correction patterns are added to the corners of the pattern on the mask pattern.

[0288] like Figures 9A to 9I As shown, a pixel can include four types of sub-pixels.

[0289] Figures 9A to 9C The pixel 178 shown is arranged in stripes.

[0290] Figure 9A This shows an example where each sub-pixel has a rectangular top surface shape. Figure 9B This shows an example where each sub-pixel has a top surface shape formed by connecting two semicircles and a rectangle. Figure 9C This shows an example where each sub-pixel has an oval top surface shape.

[0291] Figures 9D to 9F The 178 pixels shown are arranged in a matrix.

[0292] Figure 9D This shows an example where each sub-pixel has a square top surface shape. Figure 9E This example shows an instance where each sub-pixel has an approximately square top surface shape with rounded corners. Figure 9F This shows an example where each sub-pixel has a circular top surface shape.

[0293] Figure 9G and Figure 9H This shows an example of a pixel 178 arranged in two rows and three columns.

[0294] Figure 9G The pixel 178 shown includes three subpixels (subpixel 110R, subpixel 110G, and subpixel 110B) in the top row (first row) and one subpixel (subpixel 110W) in the bottom row (second row). In other words, pixel 178 includes subpixel 110R in the left column (first column), subpixel 110G in the middle column (second column), subpixel 110B in the right column (third column), and subpixel 110W across these three columns.

[0295] Figure 9HThe pixel 178 shown includes three sub-pixels (sub-pixel 110R, sub-pixel 110G, and sub-pixel 110B) in the top row (first row) and three sub-pixels 110W in the bottom row (second row). In other words, pixel 178 includes sub-pixels 110R and 110W in the left column (first column), sub-pixels 110G and 110W in the middle column (second column), and sub-pixels 110B and 110W in the right column (third column). Figure 9H As shown, by aligning the configuration of the up and down sub-pixels, dust that may be generated during the manufacturing process can be efficiently removed, for example. This provides a light-emitting device with high display quality.

[0296] exist Figure 9G and Figure 9H In the pixel 178 shown, the sub-pixels 110R, 110G, and 110B are arranged in a striped pattern, which can improve the display quality.

[0297] Figure 9I This shows an example of a pixel 178 arranged in three rows and two columns.

[0298] Figure 9I The pixel 178 shown includes subpixel 110R in the top row (first row), subpixel 110G in the middle row (second row), subpixel 110B across the first and second rows, and subpixel 110W in the bottom row (third row). In other words, pixel 178 includes subpixels 110R and 110G in the left column (first column), subpixel 110B in the right column (second column), and subpixel 110W across both columns.

[0299] exist Figure 9I In the pixel 178 shown, the layout of sub-pixels 110R, 110G, and 110B is a so-called S-striped arrangement, which can improve the display quality.

[0300] Figures 9A to 9I Pixel 178 shown is composed of four sub-pixels: sub-pixel 110R, sub-pixel 110G, sub-pixel 110B, and sub-pixel 110W. For example, sub-pixel 110R can be set to emit red light, sub-pixel 110G can be set to emit green light, sub-pixel 110B can be set to emit blue light, and sub-pixel 110W can be set to emit white light. Alternatively, at least one of sub-pixels 110R, 110G, 110B, and 110W can be set to emit cyan light, magenta light, yellow light, or near-infrared light.

[0301] As described above, in one aspect of the light-emitting device of the present invention, various layouts can be adopted for pixels composed of sub-pixels including light-emitting devices.

[0302] This embodiment can be appropriately combined with other embodiments or examples. Furthermore, where multiple structural examples are shown in one embodiment in this specification, these structural examples can be appropriately combined.

[0303] Implementation Method 5 In this embodiment, a light-emitting device according to one aspect of the present invention will be described.

[0304] The light-emitting device in this embodiment can be a high-definition light-emitting device. Therefore, for example, the light-emitting device in this embodiment can be used as a display unit for information terminal devices (wearable devices) such as watch-type and bracelet-type devices, as well as a display unit for wearable devices that can be worn on the head, such as head-mounted displays (HMDs) for VR devices and glasses-type AR devices.

[0305] Furthermore, the light-emitting device in this embodiment can be a high-resolution light-emitting device or a large light-emitting device. Therefore, the light-emitting device in this embodiment can be used, for example, as a display unit for devices such as: electronic devices with large screens, such as television devices, desktop or laptop personal computers, monitors for computers, digital signage, and large game machines such as pinball machines; digital cameras; digital video cameras; digital photo frames; mobile phones; portable game consoles; portable information terminals; and sound reproduction devices.

[0306] [Display Module] Figure 10A A perspective view of display module 280 is shown. Display module 280 includes display device 100A and FPC 290. Note that the light-emitting devices included in display module 280 are not limited to display device 100A, but may be any of display devices 100B to 100F, which will be described later.

[0307] The display module 280 includes a substrate 291 and a substrate 292. The display module 280 includes a display section 281. The display section 281 is the image display area in the display module 280, and is the area where light from each pixel disposed in the pixel section 284 can be seen.

[0308] Figure 10BThis is a three-dimensional schematic diagram of the structure on one side of the substrate 291. A circuit section 282, a pixel circuit section 283 on the circuit section 282, and a pixel section 284 on the pixel circuit section 283 are stacked on the substrate 291. Furthermore, a terminal section 285 for connecting to the FPC 290 is provided on the portion of the substrate 291 that does not overlap with the pixel section 284. The terminal section 285 is electrically connected to the circuit section 282 via a wiring section 286 composed of multiple wirings.

[0309] The pixel unit 284 includes a plurality of pixels 284a arranged periodically. Figure 10B The right side shows a magnified view of pixel 284a. Pixel 284a can adopt various structures described in the above embodiments. Figure 10B Pixel 284a is shown to have the same Figure 7A The example shown is of the same structure as pixel 178.

[0310] The pixel circuit section 283 includes a plurality of pixel circuits 283a arranged periodically.

[0311] A pixel circuit 283a controls the driving of multiple elements included in a pixel 284a. A pixel circuit 283a may contain three circuits controlling the emission of a light-emitting device. For example, the pixel circuit 283a may employ a structure that includes at least one selection transistor, one current control transistor (driving transistor), and a capacitor for each light-emitting device. In this case, the gate of the selection transistor is input with a gate signal, and the source or drain is input with a video signal. This realizes an active matrix type light-emitting device.

[0312] The circuit section 282 includes circuitry for driving each pixel circuit 283a of the pixel circuit section 283. For example, it preferably includes one or both of a gate line driving circuit and a source line driving circuit. Furthermore, it may include at least one of an arithmetic circuit, a storage circuit, and a power supply circuit.

[0313] The FPC290 is used for wiring to supply video signals or power potentials to the circuit section 282 from the outside. Additionally, ICs can be mounted on the FPC290.

[0314] The display module 280 can adopt a structure in which one or both of the pixel circuit section 283 and the circuit section 282 are stacked on the lower side of the pixel section 284, so that the display section 281 can have an extremely high aperture ratio (effective display area ratio). For example, the aperture ratio of the display section 281 can be 40% or more and less than 100%, preferably 50% or more and less than 95%, more preferably 60% or more and less than 95%. In addition, the pixels 284a can be arranged in an extremely high density, thereby enabling the display section 281 to have extremely high resolution. For example, the display section 281 preferably has a resolution of 2000 ppi or more, more preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more and less than 20000 ppi or less or less than 30000 ppi.

[0315] The aforementioned display module 280 boasts extremely high resolution, making it suitable for use in VR devices such as HMDs or AR glasses-type devices. For example, because the display module 280 features a display section 281 with exceptionally high resolution, even when viewing the display section through a lens and magnifying it, no pixels are visible, thus achieving a highly immersive display experience. Furthermore, not limited to this, the display module 280 can also be applied to electronic devices with smaller display sections. For example, it is suitable for display sections in wearable electronic devices such as watches.

[0316] [Display Device 100A] Figure 11A The display device 100A shown includes a substrate 301, light-emitting devices 130R, 130G, 130B, a capacitor 240, and a transistor 310.

[0317] Substrate 301 is equivalent to Figure 10A and Figure 10B The substrate 291 is used in the transistor 310. 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 portion 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 serves as the gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and serves as the gate insulating layer. The low-resistance region 312 is a region in the substrate 301 doped with impurities and serves as the source or drain. The insulating layer 314 covers the sides of the conductive layer 311.

[0318] In addition, a component separation layer 315 is provided between two adjacent transistors 310 in a manner embedded in the substrate 301.

[0319] In addition, an insulating layer 261 is provided to cover the transistor 310, and a capacitor 240 is provided on the insulating layer 261.

[0320] The capacitor 240 includes a conductive layer 241, a conductive layer 245, and an insulating layer 243 located therebetween. The conductive layer 241 is used as one electrode in the capacitor 240, the conductive layer 245 is used as the other electrode in the capacitor 240, and the insulating layer 243 is used as the dielectric of the capacitor 240.

[0321] A conductive layer 241 is disposed on an insulating layer 261 and embedded within an insulating layer 254. The conductive layer 241 is electrically connected to one of the source and drain terminals of the transistor 310 via a connector 271 embedded in the insulating layer 261. An insulating layer 243 is disposed to cover the conductive layer 241. A conductive layer 245 is disposed in the region where it overlaps with the conductive layer 241, separated by the insulating layer 243.

[0322] An insulating layer 255 is provided to cover the capacitor 240, and an insulating layer 174 is provided on the insulating layer 255. An insulating layer 175 is provided on the insulating layer 174. Light-emitting devices 130R, 130G, and 130B are provided on the insulating layer 175. Figure 11A The light-emitting devices 130R, 130G, and 130B are shown to have Figure 1A The example shown is a stacked structure. An insulator is disposed in the region between adjacent light-emitting devices. For example, in... Figure 11A In this region, an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 are provided.

[0323] An insulating layer 156R is provided such that it overlaps with the side surface of the conductive layer 151R included in the light-emitting device 130R; an insulating layer 156G is provided such that it overlaps with the side surface of the conductive layer 151G included in the light-emitting device 130G; and an insulating layer 156B is provided such that it overlaps with the side surface of the conductive layer 151B included in the light-emitting device 130B. Furthermore, a conductive layer 152R is provided such that it covers the conductive layer 151R and the insulating layer 156R; a conductive layer 152G is provided such that it covers the conductive layer 151G and the insulating layer 156G; and a conductive layer 152B is provided such that it covers the conductive layer 151B and the insulating layer 156B. Furthermore, the sacrificial layer 158R is located on the organic compound layer 103R included in the light-emitting device 130R, the sacrificial layer 158G is located on the organic compound layer 103G included in the light-emitting device 130G, and the sacrificial layer 158B is located on the organic compound layer 103B included in the light-emitting device 130B.

[0324] Conductive layers 151R, 151G, and 151B are electrically connected to one of the source and drain terminals of transistor 310 via plugs 256 embedded in insulating layers 243, 255, 174, and 175, conductive layer 241 embedded in insulating layer 254, and plug 271 embedded in insulating layer 261. The height of the top surface of insulating layer 175 is the same as or approximately the same as the height of the top surface of plug 256. Various conductive materials can be used for the plugs.

[0325] Furthermore, a protective layer 135 is provided on the light-emitting devices 130R, 130G, and 130B. A substrate 120 is bonded to the protective layer 135 by a resin layer 122. Detailed descriptions of the components of the light-emitting devices 130 and 120 can be found in Embodiment 3. The substrate 120 corresponds to... Figure 10A Substrate 292.

[0326] Figure 11B Show Figure 11A A modified example of the display device 100A shown. Figure 11B The illustrated light-emitting device includes coloring layers 136R, 136G, and 136B, and the light-emitting device 130 has a region overlapping one of coloring layers 136R, 136G, and 136B. Figure 11B In the light-emitting device shown, the light-emitting device 130 can emit white light, for example. In addition, coloring layers 136R, 136G and 136B can transmit red light, green light and blue light, respectively.

[0327] [Display device 100B] Figure 12 A perspective view of the display device 100B is shown. Figure 13A A cross-sectional view of the display device 100B is shown.

[0328] The display device 100B has a structure that bonds substrate 352 and substrate 351. Figure 12 In the image, substrate 352 is represented by a dashed line.

[0329] The display device 100B includes a pixel unit 177, a connection unit 140, a circuit 356, and wiring 355, etc. Figure 12 An example is shown where a display device 100B is equipped with an IC (integrated circuit) 354 and an FPC 353. Therefore, it is also possible to... Figure 12 The structure shown is referred to as a display module including display device 100B, IC, and FPC. Here, the substrate on which the light-emitting device, such as the FPC, is mounted, or the substrate on which the IC is mounted, is referred to as the display module.

[0330] The connecting portion 140 is disposed on the outer side of the pixel portion 177. The connecting portion 140 may be disposed along one or more edges of the pixel portion 177. There may also be one or more connecting portions 140. Figure 12 An example is shown where the connecting portion 140 is arranged around the four sides of the pixel portion 177. In the connecting portion 140, the common electrode of the light-emitting device is electrically connected to the conductive layer, and a potential can be supplied to the common electrode.

[0331] For example, a scan line drive circuit can be used as circuit 356.

[0332] Wiring 355 has the function of supplying signals and power to pixel unit 177 and circuit 356. The signals and power are input to wiring 355 from the outside via FPC 353 or from IC 354.

[0333] Figure 12 An example is shown where IC 354 is mounted on substrate 351 using COG (Chip On Glass) or COF (Chip On Film) methods. IC 354 can be, for example, an IC including scan line drive circuitry or signal line drive circuitry. Note that it is not necessary for display device 100B and display module to have an IC mounted on them. Alternatively, IC can be mounted on an FPC using COF method, for example.

[0334] Figure 13A An example is shown where a portion of the display device 100B including the FPC 353, a portion of the circuit 356, a portion of the pixel portion 177, a portion of the connecting portion 140, and a portion of the region including the end are cut off.

[0335] Figure 13A The display device 100B shown includes transistors 201 and 205, a light-emitting device 130R that emits red light, a light-emitting device 130G that emits green light, and a light-emitting device 130B that emits blue light, etc., between substrates 351 and 352.

[0336] Aside from the difference in pixel electrode structure, the light-emitting devices 130R, 130G, and 130B all have... Figure 1A The layered structure is shown. For details regarding the light-emitting device, please refer to the above-described embodiments.

[0337] Light-emitting device 130R includes a conductive layer 224R, a conductive layer 151R on the conductive layer 224R, and a conductive layer 152R on the conductive layer 151R. Light-emitting device 130G includes a conductive layer 224G, a conductive layer 151G on the conductive layer 224G, and a conductive layer 152G on the conductive layer 151G. Light-emitting device 130B includes a conductive layer 224B, a conductive layer 151B on the conductive layer 224B, and a conductive layer 152B on the conductive layer 151B. Here, conductive layers 224R, 151R, and 152R can be collectively referred to as the pixel electrodes of light-emitting device 130R, or conductive layers 151R and 152R, excluding conductive layer 224R, can be referred to as the pixel electrodes of light-emitting device 130R. Similarly, conductive layers 224G, 151G, and 152G can be collectively referred to as the pixel electrodes of the light-emitting device 130G, or conductive layers 151G and 152G (excluding conductive layer 224G) can be referred to as the pixel electrodes of the light-emitting device 130G. Furthermore, conductive layers 224B, 151B, and 152B can be collectively referred to as the pixel electrodes of the light-emitting device 130B, or conductive layers 151B and 152B (excluding conductive layer 224B) can be referred to as the pixel electrodes of the light-emitting device 130B.

[0338] The conductive layer 224R is connected to the conductive layer 222b included in the transistor 205 through an opening provided in the insulating layer 214. The end of the conductive layer 151R is located outside the end of the conductive layer 224R. The insulating layer 156R is provided such that it has a region in contact with the side of the conductive layer 151R, and the conductive layer 152R is provided such that it covers the conductive layer 151R and the insulating layer 156R.

[0339] The conductive layers 224G, 151G, 152G, and 156G in the light-emitting device 130G, and the conductive layers 224B, 151B, 152B, and 156B in the light-emitting device 130B, are the same as the conductive layers 224R, 151R, 152R, and 156R in the light-emitting device 130R, so detailed descriptions are omitted.

[0340] The conductive layers 224R, 224G, and 224B have recesses formed in a manner that cover the openings provided in the insulating layer 214. These recesses are filled with layer 128.

[0341] Layer 128 has the function of planarizing the recesses of conductive layers 224R, 224G, and 224B. Conductive layers 151R, 151G, and 151B, which are electrically connected to conductive layers 224R, 224G, and 224B, are disposed on conductive layers 224R, 224G, and 224B. Therefore, the area overlapping the recesses of conductive layers 224R, 224G, and 224B can also be used as a light-emitting area, which can improve the pixel aperture ratio.

[0342] Layer 128 can also be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be suitably used for layer 128. In particular, layer 128 is preferably formed using an insulating material, and more preferably using an organic insulating material. For example, organic insulating materials that can be used in the aforementioned insulating layer 127 can be used for layer 128.

[0343] A protective layer 135 is provided on light-emitting devices 130R, 130G, and 130B. The protective layer 135 is bonded to the substrate 352 by an adhesive layer 142. A light-shielding layer 157 is provided on the substrate 352. The light-emitting device 130 can be sealed using a solid sealing structure or a hollow sealing structure, etc. Figure 13A In this configuration, the space between substrates 352 and 351 is filled with adhesive layer 142, thus employing a solid sealing structure. Alternatively, an inactive gas (such as nitrogen or argon) can be used to fill the space, resulting in a hollow sealing structure. In this case, adhesive layer 142 can also be configured in a frame shape to avoid overlapping with the light-emitting device. Furthermore, a resin different from the frame-shaped adhesive layer 142 can be used to fill the space.

[0344] Figure 13A An example is shown below: the connecting portion 140 includes a conductive layer 224C obtained by processing a conductive film identical to conductive layers 224R, 224G, and 224B; a conductive layer 151C obtained by processing a conductive film identical to conductive layers 151R, 151G, and 151B; and a conductive layer 152C obtained by processing a conductive film identical to conductive layers 152R, 152G, and 152B. Additionally, Figure 13A An example is shown in which the insulating layer 156C is arranged in such a way that it has a region that overlaps with the side of the conductive layer 151C.

[0345] Display device 100B is a top-emitting display device. The light-emitting device emits light onto one side of substrate 352. Substrate 352 is preferably made of a material with high visible light transmittance. Pixel electrodes contain a material that reflects visible light, and the counter electrode (common electrode 155) contains a material that allows visible light to pass through.

[0346] Transistor 201 and transistor 205 are both formed on substrate 351. These transistors can be formed using the same material and the same process.

[0347] An insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are sequentially disposed on a substrate 351. A portion of insulating layer 211 serves as the gate insulating layer for each transistor. A portion of insulating layer 213 serves as the gate insulating layer for each transistor. Insulating layer 215 is disposed to cover the transistor. Insulating layer 214 is disposed to cover the transistor and serves as a planarization layer. Furthermore, there is no particular limitation on the number of gate insulating layers and the number of insulating layers covering the transistor; there can be one or more.

[0348] Preferably, at least one of the insulating layers covering the transistor is made of a material that does not readily diffuse impurities such as water and hydrogen. This allows the insulating layer to function as a barrier layer. By employing this structure, the diffusion of impurities from the outside into the transistor can be effectively suppressed, thereby improving the reliability of the light-emitting device.

[0349] Inorganic insulating films are preferably used as insulating layers 211, 213, and 215. Examples of inorganic insulating films include silicon nitride films, silicon oxynitride films, silicon oxide films, silicon oxynitride films, aluminum oxide films, or aluminum nitride films. Additionally, hafnium oxide films, yttrium oxide films, zirconium oxide films, gallium oxide films, tantalum oxide films, magnesium oxide films, lanthanum oxide films, cerium oxide films, and neodymium oxide films can also be used. Furthermore, two or more of the above-mentioned insulating films may be laminated.

[0350] The insulating layer 214, used as a planarization layer, is preferably an organic insulating layer. Examples of materials suitable for use as organic insulating layers include acrylic resins, polyimide resins, epoxy resins, polyamide resins, polyimide amide resins, silicone resins, benzocyclobutene resins, phenolic resins, and precursors of the aforementioned resins. Furthermore, the insulating layer 214 may also have a laminated structure of organic and inorganic insulating layers. The outermost layer of the insulating layer 214 is preferably used as an etching protection layer. This prevents the formation of recesses in the insulating layer 214 during the processing of conductive layers 224R, 151R, or 152R. Alternatively, recesses may be formed in the insulating layer 214 during the processing of conductive layers 224R, 151R, or 152R.

[0351] Transistors 201 and 205 include: a conductive layer 221 serving as a gate; an insulating layer 211 serving as a gate insulating layer; conductive layers 222a and 222b serving as source and drain, respectively; a semiconductor layer 231; an insulating layer 213 serving as a gate insulating layer; and a conductive layer 223 serving as a gate. Here, multiple layers obtained by processing the same conductive film are given the same shaded lines. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

[0352] There are no particular limitations on the transistor structure included in the light-emitting device of this embodiment. For example, planar transistors, interleaved transistors, or anti-interleaved transistors can be used. Furthermore, the transistors can have either a top-gate structure or a bottom-gate structure. Alternatively, gates can be provided above and below the semiconductor layer forming the channel.

[0353] Transistors 201 and 205 employ a structure in which a semiconductor layer forming a channel is sandwiched between two gates. Alternatively, the two gates can be connected and the same signal supplied to both gates to drive the transistor. Or, the threshold voltage of the transistor can be controlled by applying a potential to one of the two gates to control the threshold voltage and applying a potential to the other to drive it.

[0354] There are no particular restrictions on the crystallinity of the semiconductor material used in transistors; amorphous semiconductors, crystalline semiconductors (microcrystalline semiconductors, polycrystalline semiconductors, single-crystal semiconductors, or semiconductors with a portion of crystalline regions) can be used. Crystalline semiconductors are preferred because they can suppress transistor performance degradation.

[0355] The semiconductor layer of the transistor preferably comprises a metal oxide. That is, the light-emitting device of this embodiment preferably uses a transistor (hereinafter, an OS transistor) that comprises a metal oxide in the channel forming region.

[0356] Examples of crystalline oxide semiconductors include CAAC (c-axis-aligned crystalline)-OS and nc (nanocrystalline)-OS.

[0357] Alternatively, transistors (Si transistors) in which silicon is used for the channel formation region can also be used. Examples of silicon include monocrystalline silicon, polycrystalline silicon, or amorphous silicon. In particular, transistors containing low-temperature polysilicon (LTPS) in the semiconductor layer (hereinafter also referred to as LTPS transistors) can be used. LTPS transistors have high field-effect mobility and good frequency characteristics.

[0358] By using Si transistors such as LTPS transistors, circuits requiring high-frequency driving (e.g., source driver circuits) and display sections can be formed on the same substrate. Therefore, the external circuitry mounted to the light-emitting device can be simplified, reducing component and installation costs.

[0359] Compared to transistors using amorphous silicon, OS transistors have a very high field-effect mobility. Furthermore, OS transistors exhibit extremely low leakage current between the source and drain in the off state, allowing them to retain the charge stored in the capacitor connected in series with the transistor for extended periods. Additionally, the use of OS transistors can reduce the power consumption of light-emitting devices.

[0360] Furthermore, to increase the luminous brightness of the light-emitting device included in the pixel circuit, it is necessary to increase the current flowing through the light-emitting device. For this purpose, it is necessary to increase the source-drain voltage of the driving transistor included in the pixel circuit. Because the source-drain breakdown voltage of an OS transistor is higher than that of a Si transistor, a high voltage can be applied between the source and drain of the OS transistor. Therefore, by using an OS transistor as the driving transistor included in the pixel circuit, the current flowing through the light-emitting device can be increased, thereby improving the luminous brightness of the light-emitting device.

[0361] Furthermore, regarding the saturation characteristics of the current flowing through a transistor when operating in the saturation region, compared to a Si transistor, an OS transistor can maintain a stable current (saturation current) even when the source-drain voltage is gradually increased. Therefore, by using an OS transistor as a driving transistor, a stable current can flow through the light-emitting device even if the current-voltage characteristics of the device, for example, become non-uniform. In other words, when operating in the saturation region, the source-drain current of an OS transistor remains almost unchanged even when the source-drain voltage is increased, thus stabilizing the brightness of the light-emitting device.

[0362] As described above, by using OS transistors as driving transistors included in pixel circuits, it is possible to achieve "suppression of black impurities", "increase in luminous brightness", "multi-grayscale conversion" and "suppression of non-uniformity of light-emitting devices".

[0363] For example, the semiconductor layer preferably comprises indium, M (M being one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, M is preferably one or more selected from aluminum, gallium, yttrium, and tin.

[0364] In particular, as the semiconductor layer, an oxide containing indium (In), gallium (Ga), and zinc (Zn) (also denoted as IGZO) is preferred. Alternatively, an oxide containing indium, tin, and zinc is preferred. Alternatively, an oxide containing indium, gallium, tin, and zinc is preferred. Alternatively, an oxide containing indium (In), aluminum (Al), and zinc (Zn) (also denoted as IAZO) is preferred. Alternatively, an oxide containing indium (In), aluminum (Al), gallium (Ga), and zinc (Zn) (also denoted as IAGZO) is preferred. Alternatively, an oxide containing (In) (also denoted as IO) is preferred.

[0365] When using In-M-Zn oxide in a semiconductor layer, the ratio of the number of In atoms in the In-M-Zn oxide is preferably greater than or equal to the number of M atoms. Examples of possible atomic ratios of the metallic elements in this In-M-Zn oxide include: In:M:Zn = 1:1:1 or similar; In:M:Zn = 1:1:1.2 or similar; In:M:Zn = 2:1:3 or similar; In:M:Zn = 3:1:2 or similar; In:M:Zn = 4:2:3 or similar; In:M:Zn = 4:2:4.1 or similar; In:M:Zn = 5:1:3 or similar; In:M:Zn = 5:1:6 or similar; In:M:Zn = 5:1:7 or similar; In:M:Zn = 5:1:8 or similar; In:M:Zn = 6:1:6 or similar; In:M:Zn = 5:2:5 or similar; etc. Furthermore, "similar" composition includes a range of ±30% of the desired atomic ratio.

[0366] When the atomic ratio of the metallic elements is recorded as In:Ga:Zn = 4:2:3 or similar, the content ratio of each element is as follows: when In is 4, Ga is 1 or more and 3 or less, and Zn is 2 or more and 4 or less. Furthermore, when the atomic ratio of the metallic elements is recorded as In:Ga:Zn = 5:1:6 or similar, the content ratio of each element is as follows: when In is 5, Ga is greater than 0.1 and 2 or less, and Zn is 5 or more and 7 or less. Furthermore, when the atomic ratio of the metallic elements is recorded as In:Ga:Zn = 1:1:1 or similar, the content ratio of each element is as follows: when In is 1, Ga is greater than 0.1 and 2 or less, and Zn is greater than 0.1 and 2 or less.

[0367] The transistors included in circuit 356 and the transistors included in pixel unit 177 can have the same structure or different structures. Similarly, the multiple transistors included in circuit 356 can have the same structure or more than two different structures.

[0368] All transistors included in the pixel section 177 can be OS transistors, all transistors included in the pixel section 177 can be Si transistors, some transistors included in the pixel section 177 can be OS transistors and the remaining transistors can be Si transistors.

[0369] For example, by using both LTPS transistors and OS transistors in the pixel section 177, a light-emitting device with low power consumption and high driving capability can be realized. Furthermore, the structure combining LTPS transistors and OS transistors is sometimes referred to as LTPO. Moreover, for example, it is preferable to use an OS transistor as a switch for controlling the wiring (turning on and off) and an LTPS transistor as a transistor for controlling the current.

[0370] For example, one of the transistors included in the pixel section 177 is used as a transistor to control the current flowing through the light-emitting device, and can be referred to as a driving transistor. One of the source and drain of the driving transistor is electrically connected to the pixel electrode of the light-emitting device. An LTPS transistor is preferably used as this driving transistor. Therefore, the current flowing through the light-emitting device in the pixel circuit can be increased.

[0371] On the other hand, one of the transistors included in the pixel section 177 is used as a switch to control the selection and non-selection of the pixel, and can be referred to as a selection transistor. The gate of the selection transistor is electrically connected to the gate line, and one of the source and drain is electrically connected to the source line (signal line). An OS transistor is preferably used as the selection transistor. Therefore, since the grayscale of the pixel can be maintained even at extremely low frame rates (e.g., below 1 fps), power consumption can be reduced by stopping the driver when displaying a static image.

[0372] Thus, the light-emitting device of one aspect of the present invention can simultaneously possess high aperture ratio, high definition, high display quality, and low power consumption.

[0373] Note that one embodiment of the light-emitting device of the present invention employs a structure including an OS transistor and a light-emitting device having an MML (Metal Mask Less) structure. By employing this structure, the leakage current flowing through the transistor and the leakage current flowing between adjacent light-emitting devices (sometimes referred to as lateral leakage current, transverse leakage current, or horizontal leakage current) can be extremely low. Furthermore, by employing the above structure, when an image is displayed on the light-emitting device, the viewer can observe one or more of the following: image sharpness, image clarity, high color saturation, and high contrast. Moreover, by employing a structure with extremely low leakage current flowing through the transistor and extremely low transverse leakage current between light-emitting devices, minimal light leakage (so-called impure black) that can occur when displaying black can be achieved.

[0374] In particular, when the above-mentioned SBS (Side By Side) structure is used in the light-emitting device with MML structure to form light-emitting layers or to coat light-emitting layers separately, the layer disposed between the light-emitting devices (also known as the organic layer or common layer used between the light-emitting devices) is broken, thereby eliminating side leakage current or making side leakage current extremely low.

[0375] Figure 13B and Figure 13C Other examples of transistor structures are shown.

[0376] Transistors 209 and 210 include: a conductive layer 221 serving as a gate; an insulating layer 211 serving as a gate insulating layer; a semiconductor layer 231 having a channel formation region 231i and a pair of low-resistance regions 231n; a conductive layer 222a connected to one of the pair of low-resistance regions 231n; a conductive layer 222b connected to the other of the pair of low-resistance regions 231n; an insulating layer 225 serving as a gate insulating layer; a conductive layer 223 serving as a gate; and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel formation region 231i. The insulating layer 225 is located at least between the conductive layer 223 and the channel formation region 231i. Furthermore, an insulating layer 218 covering the transistor may also be provided.

[0377] exist Figure 13B In the example shown, in transistor 209, insulating layer 225 covers the top and side surfaces of semiconductor layer 231. Conductive layers 222a and 222b are connected to low-resistance region 231n through openings provided in insulating layers 225 and 215. One of conductive layers 222a and 222b is used as the source, and the other is used as the drain.

[0378] On the other hand, Figure 13CIn the transistor 210 shown, the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231 but not with the low-resistance region 231n. For example, it can be manufactured by processing the insulating layer 225 using the conductive layer 223 as a mask. Figure 13C The structure shown. In Figure 13C In the middle, insulating layer 215 covers insulating layer 225 and conductive layer 223, and conductive layer 222a and conductive layer 222b are respectively connected to low resistance region 231n through openings in insulating layer 215.

[0379] A connection portion 204 is provided in a region of substrate 351 that does not overlap with substrate 352. In the connection portion 204, wiring 355 is electrically connected to FPC 353 via conductive layer 166 and connection layer 242. An example is shown where conductive layer 166 has a stacked structure consisting of a conductive film processed from the same conductive films as conductive layers 224R, 224G, and 224B; a conductive film processed from the same conductive films as conductive layers 151R, 151G, and 151B; and a conductive film processed from the same conductive films as conductive layers 152R, 152G, and 152B. Conductive layer 166 is exposed on the top surface of connection portion 204. Therefore, connection portion 204 can be electrically connected to FPC 353 via connection layer 242.

[0380] Preferably, a light-shielding layer 157 is provided on the surface of the substrate 352 on the substrate 351 side. The light-shielding layer 157 can be provided between adjacent light-emitting devices, in the connection portion 140, and in the circuit 356, etc. In addition, various optical components can be arranged on the outer side of the substrate 352.

[0381] Substrate 351 and substrate 352 may each be made of a material that can be used in substrate 120.

[0382] As the adhesive layer 142, a material suitable for the resin layer 122 can be used.

[0383] As the connecting layer 242, anisotropic conductive film (ACF) or anisotropic conductive paste (ACP) can be used.

[0384] [Display Device 100C] Figure 14 The display device 100C shown is Figure 13A The main difference between the display device 100B and the display device 100C is that the display device 100C is a bottom-emitting type light-emitting device.

[0385] The light emitted by the light-emitting device is directed onto one side of the substrate 351. The substrate 351 is preferably made of a material with high transmittance to visible light. On the other hand, there are no restrictions on the transmittance of the material used for the substrate 352.

[0386] Preferably, a light-shielding layer 157 is formed between the substrate 351 and the transistor 201 and between the substrate 351 and the transistor 205. Figure 14 An example is shown where a light-shielding layer 157 is disposed on a substrate 351, an insulating layer 153 is disposed on the light-shielding layer 157, and transistors 201, 205, etc. are disposed on the insulating layer 153.

[0387] The light-emitting device 130R includes a conductive layer 112R, a conductive layer 126R on the conductive layer 112R, and a conductive layer 129R on the conductive layer 126R.

[0388] The light-emitting device 130B includes a conductive layer 112B, a conductive layer 126B on the conductive layer 112B, and a conductive layer 129B on the conductive layer 126B.

[0389] The conductive layers 112R, 112B, 126R, 126B, 129R, and 129B all use materials with high transmittance to visible light. The common electrode 155 preferably uses a material that reflects visible light.

[0390] Note that, although Figure 14 The light-emitting device 130G is not shown in the figure, but it is still provided.

[0391] In addition, although Figure 14 Examples of layer 128 with a flat portion on the top surface are shown, but there are no particular restrictions on the shape of layer 128.

[0392] [Display Device 100D] Figures 15A to 15C The display device 100D shown is related to Figure 14 This is an example of a bottom-emitting display device different from the display device 100C. The display device 100D includes an organic resin layer 180, which differs from the display device 100C. Note that details different from those in the drawings are sometimes omitted. Figure 14 For details regarding symbols representing the same constituent elements, please refer to [link / reference]. Figure 14 The records.

[0393] in addition, Figure 15B The diagram shows a top view layout of pixels 178 (pixels 178a and 178b) including sub-pixels 110 (sub-pixels 110R, 110G, 110B, and 110W). Figure 15CA top view of the organic resin layer 180 in the region forming sub-pixels 110R and 110W included in pixel 178 is shown. Note that the width 110Rw in the light-emitting region of sub-pixel 110R is between the light-shielding layers 317 and 317.

[0394] like Figure 15A As shown, the organic resin layer 180 is disposed on the insulating layer 214. (As indicated...) Figure 15A The area enclosed by dotted lines and Figure 15C As shown, the organic resin layer 180 includes at least a curved recess 181 (recess 181a, recess 181b) in the region forming the sub-pixel. Alternatively, the recess 181 may be disposed outside the light-emitting region, as in recess 181c. By providing the recess 181c, light emitted in the region overlapping with the light-shielding layer 317, or light entering the region overlapping with the light-shielding layer 317, can be extracted from the light-emitting region through refraction, thereby improving luminous efficiency.

[0395] Multiple recesses 181 can also be formed in a matrix. Recesses 181a and 181b can be disposed in contact with each other or have a plane between them.

[0396] In addition, Figure 15A and Figure 15C In the middle, the top surface of the concave part is hexagonal in shape. Figure 15C The cross-sectional shape is semi-circular. Figure 15A However, other shapes can also be used as needed. For example, the top surface shape of the concave part can be a triangle, a quadrilateral (including a rectangle and a square), a pentagon or other polygon, the above-mentioned polygonal shapes with rounded corners, an ellipse or a circle, etc.

[0397] As the organic resin layer 180, an insulating layer containing organic materials can be used. For example, as the organic resin layer 180, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimide amide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenolic resin, and precursors of these resins can be used. Furthermore, as the organic resin layer 180, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerol, pullulan, water-soluble cellulose, or polyamide resins soluble in alcohols can also be used.

[0398] Furthermore, a photosensitive resin can be used as the organic resin layer 180. A photoresist can also be used as the photosensitive resin. The photosensitive resin can be either a positive or negative material.

[0399] The organic resin layer 180 may also contain materials that absorb visible light. For example, the organic resin layer 180 itself may be composed of materials that absorb visible light, and the organic resin layer 180 may also contain pigments that absorb visible light. As the organic resin layer 180, for example, a resin that can be used as a color filter that allows red, blue, or green light to pass through and absorbs other light, or a resin that contains carbon black as a pigment and is used as a black matrix, etc.

[0400] Additionally, the organic resin layer 180 includes a first electrode 101 (first electrode 101R and first electrode 101W), and the first electrode 101 includes an organic compound layer 103. The ends of the first electrode 101 and the organic compound layer 103 may also be covered by an insulating layer 127.

[0401] Furthermore, the first electrode 101 formed on the organic resin layer 180 also has a recess along the recess of the organic resin layer 180. Furthermore, the organic compound layer 103 formed on the first electrode 101 also has a recess along the recess of the first electrode 101. Furthermore, the common layer 104 formed on the organic compound layer 103 also has a recess along the recess of the organic compound layer 103. Furthermore, the common electrode 155 formed on the common layer 104 also has a recess along 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 common electrode 155 overlap each other.

[0402] Additionally, a common layer 104 is included on the organic compound layer 103 and the insulating layer 127, and a common electrode 155 is included on the common layer 104. A protective layer 135 is provided on the common electrode 155, and it is attached to the substrate 352 through an adhesive layer 142.

[0403] Note that, although in Figures 15A to 15C The light-emitting devices 130G and 130B are not shown in the figure, but light-emitting devices 130G and 130B are also provided.

[0404] [Display Device 100E] Figure 16A The display device 100E shown is Figure 13A The top-emitting display device 100B shown is a modified example of the top-emitting display device 100B. The display device 100E includes a color layer 136R, a color layer 136G, and a color layer 136B, which is the main difference from the display device 100B.

[0405] In the display device 100E, the light-emitting device 130 has a region that overlaps with one of the coloring layers 136R, 136G, and 136B. The coloring layers 136R, 136G, and 136B can be disposed on a surface of the substrate 352 on the substrate 351 side. The ends of the coloring layers 136R, 136G, and 136B can overlap with the light-shielding layer 157.

[0406] In the display device 100E, the light-emitting device 130 can emit white light, for example. Additionally, color layers 136R, 136G, and 136B can transmit red, green, and blue light, respectively. Alternatively, the display device 100E may also employ a structure in which color layers 136R, 136G, and 136B are disposed between the protective layer 135 and the adhesive layer 142.

[0407] Although Figure 13A and Figure 16A Examples of layer 128 with a flat portion on the top surface are shown, but there are no particular restrictions on the shape of layer 128. Figures 16B to 16D A variation of layer 128 is shown.

[0408] like Figure 16B and Figure 16D As shown, in cross-section, the top surface of layer 128 can have a concave shape in the center and surrounding area, i.e., a concave curved surface shape. Furthermore, the common layer 154 can also be provided in contact with the common electrode 155.

[0409] In addition, such as Figure 16C As shown, when viewed in section, the top surface of layer 128 can have a shape that expands in the center and its vicinity, that is, a shape with a convex curved surface.

[0410] Furthermore, the top surface of layer 128 may also have one or both of a convex surface and a concave surface. Moreover, there is no limitation on the number of convex and concave surfaces on the top surface of layer 128; it can be one or more.

[0411] Furthermore, the top surface height of layer 128 can be the same as, approximately the same as, or different from the top surface height of conductive layer 224R. For example, the top surface height of layer 128 can be lower or higher than the top surface height of conductive layer 224R.

[0412] Figure 16B This can also be described as an example where layer 128 is housed within a recess formed in conductive layer 224R. On the other hand, as... Figure 16D As shown, layer 128 can also be formed in a manner that exists outside the recess formed in conductive layer 224R, that is, layer 128 can also be formed in a manner that the top surface width is greater than the recess.

[0413] [Display Device 100F] Figure 17A The display device 100F shown is Figures 13A to 13C The modified example of the top-emitting display device 100B shown includes microlenses 182 on the color layers 136R, 136G, and 136B. Note that the details are sometimes omitted in the drawings. Figures 13A to 13C For details regarding symbols representing the same constituent elements, please refer to [link / reference]. Figures 13A to 13C The records.

[0414] in addition, Figure 17B The diagram shows a top view layout of pixels 178 (pixels 178a and 178b) including sub-pixels 110 (sub-pixels 110R, 110G, and 110B). Figure 17C A top view is shown of the microlens 182 in the region comprising sub-pixels 110R, 110G, and 110B of pixel 178. Note that the area where the common electrode 155 contacts the organic compound layer 103 is the width 110Gw in the light-emitting region of sub-pixel 110G.

[0415] exist Figure 15A In the display device 100F shown, a planarization film 143 is provided on a protective layer 135, and color layers 136R, 136G, and 136B are provided on the planarization film 144. The planarization film 144 is provided to cover the color layers 136R, 136G, and 136B. A microlens 182 is provided on the planarization film 144.

[0416] In addition, such as Figure 17C As shown, it is preferable to provide a microlens 182 for each sub-pixel in the region where the sub-pixel is formed.

[0417] Note that in Figure 17C In this embodiment, the top surface of the microlens 182 is hexagonal, but other shapes can be used as needed. For example, the top surface shape of the microlens 182 can be a triangle, a quadrilateral (including a rectangle and a square), a pentagon or other polygon, the above-mentioned polygonal shapes with rounded corners, an ellipse or a circle, etc.

[0418] The microlens 182 can be formed using the same material as the organic resin layer 180.

[0419] This embodiment can be appropriately combined with other embodiments or examples. Furthermore, where multiple structural examples are shown in one embodiment in this specification, these structural examples can be appropriately combined.

[0420] Implementation Method 6 In this embodiment, an electronic device according to one aspect of the present invention will be described.

[0421] The electronic device of this embodiment includes a light-emitting device according to one aspect of the present invention in its display unit. The light-emitting device according to one aspect of the present invention has high reliability and is easily implemented with high definition and high resolution. Therefore, it can be used in the display units of various electronic devices.

[0422] As electronic devices, in addition to large-screen electronic devices such as television sets, desktop or laptop personal computers, monitors for computers, digital signage, and large game machines such as pinball machines, other examples include digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, portable information terminals, and sound reproduction devices.

[0423] In particular, because the light-emitting device of one aspect of the present invention can improve clarity, it can be suitably used in electronic devices that include a small display section. Examples of such electronic devices include watch-type and bracelet-type information terminal devices (wearable devices), wearable devices that can be worn on the head, VR devices such as head-mounted displays, AR devices such as glasses, and MR devices.

[0424] One aspect of the light-emitting device of the present invention preferably has an extremely high resolution, such as HD (1280×720 pixels), FHD (1920×1080 pixels), WQHD (2560×1440 pixels), WQXGA (2560×1600 pixels), 4K (3840×2160 pixels), 8K (7680×4320 pixels), etc. In particular, a resolution of 4K, 8K, or higher is preferred. Furthermore, the pixel density (clarity) of the light-emitting device of one aspect of the present invention is preferably 100 ppi or higher, preferably 300 ppi or higher, more preferably 500 ppi or higher, more preferably 1000 ppi or higher, more preferably 2000 ppi or higher, more preferably 3000 ppi or higher, more preferably 5000 ppi or higher, and even more preferably 7000 ppi or higher. By using the above-described light-emitting device with one or both of high resolution and high clarity, realism and depth perception can be further improved. Furthermore, there is no particular limitation on the screen ratio (aspect ratio) of the light-emitting device according to one aspect of the present invention. For example, the light-emitting device can adapt to various screen ratios such as 1:1 (square), 4:3, 16:9, and 16:10.

[0425] The electronic device in this embodiment may also include a sensor (which has the function of measuring factors such as force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, tilt, vibration, odor, or infrared radiation).

[0426] The electronic device of this embodiment can have various functions. For example, it can have the following functions: displaying various information (static images, dynamic images, text images, etc.) on the display unit; touch panel function; displaying calendar, date, or time, etc.; executing various software (programs); wireless communication function; reading programs or data stored in the storage medium; etc.

[0427] use Figures 18A to 18D This section describes an example of a wearable device that can be worn on the head. These wearable devices have at least one of the following functions: displaying AR content, displaying VR content, displaying SR content, and displaying MR content. When an electronic device has the function of displaying at least one of AR, VR, SR, and MR content, it can enhance the user's sense of immersion.

[0428] Figure 18A The electronic device 700A shown and Figure 18B The electronic devices 700B shown include a pair of display panels 751, a pair of frames 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 components 753, an eyeglass frame 757, and a pair of nose pads 758.

[0429] The display panel 751 can utilize a light-emitting device according to one aspect of the present invention. This enables the realization of a highly reliable electronic device.

[0430] Both electronic devices 700A and 700B can project images displayed on the display panel 751 onto the display area 756 in the optical component 753. Because the optical component 753 is translucent, the user can see the image displayed on the display area by overlapping the transmitted image seen through the optical component 753. Therefore, both electronic devices 700A and 700B are capable of AR display.

[0431] Both electronic devices 700A and 700B can be equipped with cameras capable of capturing images of the front as imaging units. Furthermore, by including accelerometer sensors such as gyroscopes in each of the electronic devices 700A and 700B, the orientation of the user's head can be detected, and an image corresponding to that orientation can be displayed on the display area 756.

[0432] The communications unit includes a wireless communication device through which video signals can be supplied, for example. Additionally, a connector capable of connecting cables supplying video signals and power potential may be included, either in place of the wireless communication device or in addition to the wireless communication device.

[0433] In addition, electronic devices 700A and 700B are equipped with batteries that can be charged wirelessly or via wired means, or both.

[0434] The frame 721 may also be equipped with a touch sensor module. The touch sensor module has the function of detecting whether the outer surface of the frame 721 is touched. Through the touch sensor module, various processes can be performed based on user tap or swipe operations. For example, a tap operation can temporarily pause or restart a moving image, while a swipe operation can fast forward or rewind. Furthermore, by providing a touch sensor module in each of the two frames 721, the operating range can be expanded.

[0435] Various touch sensors can be used as touch sensor modules. For example, capacitive, resistive, infrared, electromagnetic induction, surface acoustic wave, or optical sensors can be employed. In particular, capacitive or optical sensors are preferred for use in touch sensor modules.

[0436] When using an optical touch sensor, a photoelectric conversion device (also known as a photoelectric conversion element) can be used as the light-receiving element. One or both of inorganic and organic semiconductors can be used in the active layer of the photoelectric conversion device.

[0437] Figure 18C The electronic device 800A shown and Figure 18D The electronic devices 800B shown include a pair of display units 820, a frame 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.

[0438] The display unit 820 can utilize a light-emitting device according to one aspect of the present invention. This allows for the realization of a highly reliable electronic device.

[0439] The display unit 820 is located inside the housing 821 in a position visible through the lens 832. Furthermore, by displaying different images on each of the pair of display units 820, three-dimensional display utilizing parallax can be achieved.

[0440] Both electronic devices 800A and 800B can be used as VR electronic devices. Users who have installed electronic devices 800A or 800B can see the image displayed on the display unit 820 through the lens 832.

[0441] Electronic devices 800A and 800B preferably have a mechanism in which the left and right positions of the lens 832 and the display unit 820 can be adjusted so that the lens 832 and the display unit 820 are in the most suitable position according to the position of the user's eyes. Furthermore, it is preferable to have a mechanism in which the focus is adjusted by changing the distance between the lens 832 and the display unit 820.

[0442] The user can use the mounting unit 823 to attach electronic device 800A or electronic device 800B to their head. For example, in Figure 18C In this case, the mounting part 823 has a shape similar to the temple of an eyeglass (also called a hinge or temple thread, etc.), but is not limited to this. As long as the user can attach it, the mounting part 823 can have a helmet-shaped or strap-shaped shape, for example.

[0443] The imaging unit 825 has the function of acquiring external information. The data acquired by the imaging unit 825 can be output to the display unit 820. An image sensor can be used in the imaging unit 825. In addition, multiple cameras can be set to support various viewing angles such as telephoto and wide-angle.

[0444] Note that the example shown here includes an imaging unit 825, which can be a ranging sensor (hereinafter also referred to as a detection unit) capable of measuring the distance to an object. In other words, the imaging unit 825 is one type of detection unit. For example, an image sensor or a distance image sensor such as LiDAR (Light Detection and Ranging) can be used as the detection unit. By using images acquired by a camera and images acquired by a distance image sensor, more information can be obtained, enabling more precise attitude control.

[0445] The electronic device 800A may also include a vibration mechanism for use as bone conduction headphones. For example, one or more of the display unit 820, the frame 821, and the mounting unit 823 may adopt a structure including this vibration mechanism. Thus, there is no need to separately install audio equipment such as headphones, earphones, or speakers; one can enjoy images and sound simply by installing the electronic device 800A.

[0446] Electronic devices 800A and 800B may also include input terminals. Cables supplying image signals from image output devices and the like, as well as power for charging batteries installed within the electronic devices, can be connected to the input terminals.

[0447] An electronic device according to one aspect of the present invention may also have the function of wirelessly communicating with the headset 750. The headset 750 includes a communication unit (not shown) and has wireless communication functionality. The headset 750 can receive information (e.g., voice data) from the electronic device via the wireless communication function. For example, Figure 18A The illustrated electronic device 700A has the function of transmitting information to the headset 750 via wireless communication. Furthermore, for example... Figure 18C The electronic device 800A shown has the function of sending information to the headset 750 via wireless communication.

[0448] In addition, electronic devices may also include an earphone unit. Figure 18B The illustrated electronic device 700B includes an earphone unit 727. For example, a structure in which the earphone unit 727 and the control unit are connected by a wire can be adopted. A portion of the wiring connecting the earphone unit 727 and the control unit can also be configured inside the housing 721 or the mounting portion 723.

[0449] same, Figure 18D The illustrated electronic device 800B includes an earphone unit 827. For example, a structure can be adopted in which the earphone unit 827 and the control unit 824 are connected by a wire. A portion of the wiring connecting the earphone unit 827 and the control unit 824 can also be disposed inside the housing 821 or the mounting portion 823. Furthermore, the earphone unit 827 and the mounting portion 823 can also include magnets. Thus, the earphone unit 827 can be magnetically secured to the mounting portion 823, making storage easy, which is preferable.

[0450] Additionally, the electronic device may include an audio output terminal capable of connecting to headphones or headsets. Furthermore, the electronic device may include one or both of an audio input terminal and an audio input mechanism. For example, a microphone or other sound-receiving device can be used as the audio input mechanism. By including an audio input mechanism, the electronic device can function as a so-called headset.

[0451] Thus, as an embodiment of the present invention, both eyeglass type (electronic device 700A and electronic device 700B, etc.) and goggle type (electronic device 800A and electronic device 800B, etc.) are preferred electronic devices.

[0452] In addition, one aspect of the present invention allows the electronic device to transmit information to headphones in a wired or wireless manner.

[0453] Figure 19A The electronic device 6500 shown is a portable information terminal device that can be used as a smartphone.

[0454] Electronic device 6500 includes a frame 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508, etc. The display unit 6502 has a touch panel function.

[0455] The display unit 6502 can use a light-emitting device according to one aspect of the present invention. This allows for the realization of a highly reliable electronic device.

[0456] Figure 19B This is a cross-sectional schematic diagram of one end of the microphone 6506, including the frame 6501.

[0457] A light-transmitting protective component 6510 is provided on one side of the display surface of the frame 6501. The space surrounded by the frame 6501 and the protective component 6510 contains a display panel 6511, an optical component 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc.

[0458] The display panel 6511, optical component 6512, and touch sensor panel 6513 are fixed to the protective component 6510 using an adhesive layer (not shown).

[0459] In the area outside the display unit 6502, a portion of the display panel 6511 is folded, and this folded portion is connected to an FPC 6515. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to terminals disposed on a printed circuit board 6517.

[0460] The display panel 6511 can use a light-emitting device according to one aspect of the present invention. This allows for the realization of an extremely lightweight electronic device. Furthermore, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be installed while minimizing the thickness of the electronic device. Additionally, by folding a portion of the display panel 6511 to arrange the connection portion with the FPC 6515 on the back of the pixel section, a narrow-bezel electronic device can be realized.

[0461] Figure 19C An example of a television device is shown. In the television device 7100, a display unit 7000 is assembled in a frame 7171. The structure in which the frame 7171 is supported by a bracket 7173 is shown here.

[0462] The display unit 7000 can use a light-emitting device according to one aspect of the present invention. This allows for the realization of a highly reliable electronic device.

[0463] The operation can be performed using the operating switch provided in the housing 7171 and the additionally provided remote control 7151. Figure 19CThe operation of the television device 7100 shown is illustrated. Alternatively, a touch sensor may be provided in the display unit 7000, allowing operation of the television device 7100 by touching the display unit 7000 with a finger or the like. Furthermore, a display unit that displays information output from the remote control 7151 may be provided in the remote control 7151. Using the operation keys or touch panel provided in the remote control 7151, channel and volume can be adjusted, and the images displayed on the display unit 7000 can be manipulated.

[0464] In addition, the television device 7100 includes a receiver and a modem. Using the receiver, general television broadcasts can be received. Furthermore, by connecting to a wired or wireless communication network via the modem, one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers, etc.) information communication can be performed.

[0465] Figure 19D An example of a notebook computer is shown. The notebook computer 7200 includes a chassis 7211, a keyboard 7212, a pointing device 7213, and an external connection port 7214, etc. A display unit 7000 is assembled in the chassis 7211.

[0466] The display unit 7000 can use a light-emitting device according to one aspect of the present invention. This allows for the realization of a highly reliable electronic device.

[0467] Figure 19E and Figure 19F This shows an example of digital signage that can be used in shop windows and display cases.

[0468] Figure 19E The digital sign 7300 shown includes a frame 7301, a display unit 7000, and a speaker 7303. It may also include LEDs, operation keys (including a power switch or operation switch), connection terminals, various sensors, a microphone, etc.

[0469] Figure 19F A digital sign 7400 is shown mounted on a cylindrical column 7401. The digital sign 7400 includes a display section 7000 disposed along the curved surface of the column 7401.

[0470] exist Figure 19E and Figure 19F In this embodiment, the light-emitting device according to one aspect of the present invention can be used in the display unit 7000. This allows for the realization of a highly reliable electronic device.

[0471] The larger the display unit (7000), the more information it can provide at once. A larger display unit (7000) is also more likely to attract attention, which can improve the effectiveness of advertising.

[0472] In particular, when using a display device according to one aspect of the present invention... Figure 19E and Figure 19F When displaying advertisements using digital signage 7300 and 7400, the use of a light-transmitting panel increases the freedom of expression. For example, by adjusting the distance between pixel electrodes using wiring and support members of a conductive film that allows visible light to pass through, a light-transmitting display device can be manufactured.

[0473] Furthermore, by using a light-emitting device according to one aspect of the present invention, in addition to the wiring and support members that utilize a conductive film that allows visible light to pass through, as described above, the brightness of a single pixel can also be increased. In other words, good display quality can be achieved even with a reduced aperture ratio in the display device, thereby improving the light transmittance of the display section of the display device. Therefore, the above structure is suitable for use in a light-transmitting display device according to one aspect of the present invention.

[0474] like Figure 19E and Figure 19F As shown, digital signage 7300 or digital signage 7400 preferably connects wirelessly with information terminal devices 7311 or 7411, such as smartphones carried by the user. For example, advertising information displayed on display unit 7000 can be displayed on the screen of information terminal device 7311 or information terminal device 7411. Furthermore, the display on display unit 7000 can be switched by operating information terminal device 7311 or information terminal device 7411.

[0475] Furthermore, the game can be executed on the digital signage 7300 or 7400 using the screen of information terminal device 7311 or 7411 as the operating unit (controller). This allows multiple users, not specifically designated, to participate in the game simultaneously and enjoy the experience.

[0476] Figures 20A to 20G The electronic device shown includes a frame 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or operation switch), a connection terminal 9006, a sensor 9007 (which has the function of measuring the following factors: force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, tilt, vibration, odor, or infrared radiation), a microphone 9008, etc.

[0477] Figures 20A to 20GThe electronic device shown has various functions. For example, it may have the following functions: displaying various information (still images, moving images, text images, etc.) on a display unit; a touch panel function; displaying calendars, dates, or times; being controlled and processed by various software (programs); wireless communication function; reading and processing programs or data stored in a storage medium; etc. Note that the functions of the electronic device are not limited to the above functions, but can have various functions. The electronic device may also include multiple display units. In addition, a camera or the like may be installed in the electronic device to give it the following functions: capturing still or moving images and storing the captured images in a storage medium (external storage medium or storage medium built into the camera); displaying the captured images on a display unit; etc.

[0478] The following is a detailed explanation. Figures 20A to 20G The electronic device shown.

[0479] Figure 20A This is a perspective view showing a portable information terminal 9171. The portable information terminal 9171 can be used, for example, as a smartphone. Note that a speaker 9003, a connection terminal 9006, or a sensor 9007 may also be included in the portable information terminal 9171. Furthermore, as a portable information terminal 9171, text or image information can be displayed on multiple surfaces. Figure 20A The image shows an example displaying three icons 9050. Furthermore, information 9051, shown as a dashed rectangle, can be displayed on other surfaces of the display unit 9001. Examples of information 9051 include notifications of received emails, SNS messages, or phone calls; the subject of the email or SNS message; the sender's name; the date; the time; remaining battery level; and radio wave strength. Alternatively, icons 9050 can be displayed in the same location where information 9051 is displayed.

[0480] Figure 20B This is a perspective view showing a portable information terminal 9172. The portable information terminal 9172 has the function of displaying information on three or more surfaces of the display unit 9001. Here, examples are shown where information 9052, information 9053, and information 9054 are displayed on different surfaces. For example, when the portable information terminal 9172 is placed in a jacket pocket, the user can check information 9053 displayed in a position visible from above the portable information terminal 9172. For example, the user can check this display without taking the portable information terminal 9172 out of their pocket, thereby determining whether to answer a phone call.

[0481] Figure 20CThis is a perspective view of a tablet terminal 9173. The tablet terminal 9173 can, for example, execute various application software such as mobile phone, email, and article reading and editing, music playback, network communication, and computer games. The tablet terminal 9173 includes a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front of its housing 9000; operation keys 9005 serving as operating buttons on the left side of the housing 9000; and a connection terminal 9006 on the bottom surface.

[0482] Figure 20D This is a perspective view showing a watch-type portable information terminal 9200. The portable information terminal 9200 can be used, for example, as a smartwatch (registered trademark). The portable information terminal 9200 may also include operation buttons 9005 on the left side of the frame 9000 and a sensor 9007 on the bottom surface. Furthermore, as an example, a curved bracelet-type frame 9000 is shown, but a structure combining the frame 9000 with a watch strap or similar components for wearability can also be adopted. Furthermore, the display surface of the display unit 9001 is curved, allowing display along its curved surface. Furthermore, the power storage device 9004 may also have a shape that curves along the frame 9000. Furthermore, the power storage device 9004 is flexible and can be bent according to changes in shape when worn or removed. Additionally, a charging control IC connected to the power storage device 9004 may be included. Furthermore, the portable information terminal 9200 can perform hands-free calls, for example, by communicating with a headset capable of wireless communication. Furthermore, the portable information terminal 9200 can wirelessly transmit data with other information terminals and can also be charged wirelessly. Alternatively, it can transmit data and charge via a wired connection via a connection terminal 9006 located in the housing 9000.

[0483] Figures 20E to 20G This is a perspective view showing the foldable portable information terminal 9201. Furthermore, Figure 20E This is a 3D view of the portable information terminal 9201 in its unfolded state. Figure 20G It is a 3D image of the folded state. Figure 20F From Figure 20E status and Figure 20G The portable information terminal 9201 is a three-dimensional representation of the state transitioning between different states. In its folded state, it is highly portable, while in its unfolded state, it offers excellent browsing capabilities due to its large, seamlessly integrated display area. The display unit 9001 included in the portable information terminal 9201 is supported by three frames 9000 connected by hinges 9055. The display unit 9001 can be bent, for example, within a radius of curvature of 0.1 mm or more and 150 mm or less.

[0484] This embodiment can be appropriately combined with other embodiments or examples. Furthermore, where multiple structural examples are shown in one embodiment in this specification, these structural examples can be appropriately combined.

[0485] Implementation Method 7 In this embodiment, a light-emitting device using the organic EL element described in Embodiments 1 and 2 will be described.

[0486] In this embodiment, refer to Figure 21A and Figure 21B A light-emitting device manufactured using the organic EL element described in Embodiments 1 and 2 will be described. Note that... Figure 21A It is a top view showing the light-emitting device, and Figure 21B It is along Figure 21A The diagram shows a cross-sectional view of lines AB and CD cut off. This light-emitting device, as a unit for controlling the light emission of an organic EL element, includes a driving circuit section (source line driving circuit) 601 (indicated by dashed lines), a pixel section 602, and a driving circuit section (gate line driving circuit) 603. Furthermore, reference numeral 604 is a sealing substrate, reference numeral 605 is a sealing material, and the inner side surrounded by the sealing material 605 is a space 607.

[0487] Note that the guide wiring 608 is used to transmit signals input to the source line drive circuit 601 and the gate line drive circuit 603, and receives video signals, clock signals, start signals, reset signals, etc., from the FPC 609, which serves as an external input terminal. Note that although only the FPC is shown here, it can also be equipped with a printed circuit board (PWB). The light-emitting device in this specification includes not only the light-emitting device itself, but also light-emitting devices mounted on an FPC or PWB.

[0488] Below, refer to Figure 21B Explanation of the cross-sectional structure. Although a driving circuit section and a pixel section are formed on the element substrate 610, here we show one pixel that serves as the source line driving circuit 601 of the driving circuit section and one pixel of the pixel section 602.

[0489] In addition to substrates made of glass, quartz, organic resin, metal, alloy, semiconductor, etc., the component substrate 610 can also use plastic substrates made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fluoride), polyester or acrylic resin.

[0490] There are no particular restrictions on the structure of the transistors used in the pixel and driving circuitry. For example, anti-interleaved transistors or interleaved transistors can be used. Furthermore, top-gate transistors or bottom-gate transistors can also be used. There are no particular restrictions on the semiconductor materials used in the transistors; for example, silicon, germanium, silicon carbide, gallium nitride, etc., can be used. Alternatively, oxide semiconductors containing at least one of indium, gallium, and zinc, such as In-Ga-Zn metal oxides, can be used.

[0491] There are no particular restrictions on the crystallinity of the semiconductor material used in the transistor; any combination of amorphous semiconductors and crystalline semiconductors (microcrystalline semiconductors, polycrystalline semiconductors, single-crystal semiconductors, or semiconductors with a portion of crystalline regions) can be used. Using crystalline semiconductors can suppress transistor performance degradation, and is therefore preferred.

[0492] Here, oxide semiconductors are preferably used in semiconductor devices such as transistors disposed in the aforementioned pixels and driving circuits, and in transistors for touch sensors, etc., which will be described later. Oxide semiconductors with a wider bandgap than silicon are particularly preferred. By using oxide semiconductors with a wider bandgap than silicon, the off-state current of the transistors can be reduced.

[0493] The aforementioned oxide semiconductor preferably contains at least indium (In) or zinc (Zn). Furthermore, the aforementioned oxide semiconductor is more preferably an oxide semiconductor containing oxides represented by In-M-Zn type oxides (M being metals such as Al, Ti, Ga, Ge, Y, Zr, Sn, La, Ce, or Hf).

[0494] In particular, as a semiconductor layer, an oxide semiconductor film is preferably used that has a plurality of crystal portions, the c-axis of which is oriented in a direction perpendicular to the surface to which the semiconductor layer is formed or the top surface of the semiconductor layer, and there are no grain boundaries between adjacent crystal portions.

[0495] By using the aforementioned materials as semiconductor layers, highly reliable transistors with suppressed variations in electrical characteristics can be achieved.

[0496] Furthermore, because the transistors with the aforementioned semiconductor layer have low off-state currents, the charge stored in the capacitors through the transistors can be maintained for extended periods. By using such transistors in pixels, the driving circuit can be stopped while maintaining the grayscale of the image displayed in each display area. As a result, electronic devices with extremely low power consumption can be realized.

[0497] To stabilize transistor characteristics, a base film is preferably provided. As the base film, inorganic insulating films such as silicon oxide, silicon nitride, silicon oxynitride, and silicon oxynitride can be used and fabricated as a single layer or in stacks. The base film can be formed by sputtering, CVD (plasma CVD, thermal CVD, MOCVD (Metal Organic CVD), etc.), ALD, coating, printing, etc. Note that a base film may be omitted if not required.

[0498] Note that FET623 represents one of the transistors formed in the source line drive circuit 601. Furthermore, the drive circuit can also be formed using various CMOS, PMOS, or NMOS circuits. Although this embodiment shows an integrated driver type with the drive circuit formed on the substrate, this structure is not mandatory; the drive circuit can also be formed externally instead of on the substrate.

[0499] Furthermore, the pixel unit 602 is formed by a plurality of pixels, each of which includes a switching FET 611, a current control FET 612, and a first electrode 613 electrically connected to the drain of the current control FET 612. However, it is not limited to this and a pixel unit combining three or more FETs and capacitors may also be used.

[0500] Note that an insulator 614 is formed at the end covering the first electrode 613. Here, a positive photosensitive acrylic resin film can be used to form the insulator 614.

[0501] Furthermore, the upper or lower end of the insulator 614 is formed as a curved surface to obtain good coverage for the subsequently formed EL layer, etc. For example, when using a positive photosensitive acrylic resin as the material of the insulator 614, it is preferable that only the upper end of the insulator 614 includes a curved surface with a radius of curvature (0.2 μm to 3 μm). Negative or positive photosensitive resins can be used as the insulator 614.

[0502] An EL layer 616 and a second electrode 617 are formed on the first electrode 613. Here, a material with a high work function is preferably used as the material for the first electrode 613, which serves as the anode. For example, in addition to single-layer films such as ITO films, indium tin oxide films containing silicon, indium oxide films containing 2 wt% to 20 wt% zinc oxide, titanium nitride films, chromium films, tungsten films, Zn films, and Pt films, multilayer films composed of titanium nitride films and aluminum-based films, as well as three-layer structures composed of titanium nitride films, aluminum-based films, and titanium nitride films, can also be used. Note that by employing a multilayer structure, the resistance of the wiring can be lower, good ohmic contact can be obtained, and it can be used as the anode.

[0503] Furthermore, the EL layer 616 is formed using various methods such as vapor deposition using a vapor deposition mask, inkjet printing, and spin coating. The EL layer 616 includes the structures shown in Embodiments 1 and 2. When the EL layer 616 is formed from the side of the first electrode 613, if the first electrode 613 is an anode, a first hole transport layer 112_1 and a second hole transport layer 112_2 are deposited sequentially, that is, the anode, the first hole transport layer 112_1, the second hole transport layer 112_2, and the cathode are sequentially stacked from the substrate side. In addition, low-molecular-weight compounds or high-molecular-weight compounds (including oligomers and dendritic polymers) can also be used as other materials constituting the EL layer 616.

[0504] Furthermore, as the material for the second electrode 617 formed on the EL layer 616 and used as a cathode, a material with a low work function (Al, Mg, Li, Ca, or their alloys and compounds (MgAg, MgIn, AlLi, etc.)) is preferably used. Note that when light generated in the EL layer 616 is transmitted through the second electrode 617, a stack consisting of a thinned metal film and a transparent conductive film (ITO, indium oxide containing 2 wt% to 20 wt% zinc oxide, indium tin oxide containing silicon, zinc oxide (ZnO), etc.) is preferably used as the second electrode 617.

[0505] Furthermore, the organic EL element is formed by a first electrode 613, an EL layer 616, and a second electrode 617. This organic EL element is the organic EL element described in Embodiments 1 and 2. Additionally, the pixel portion is composed of multiple organic EL elements, and the light-emitting device of this embodiment may also include both the organic EL element described in Embodiments 1 and 2 and organic EL elements having other structures.

[0506] Furthermore, by attaching the sealing substrate 604 to the element substrate 610 using a sealing material 605, the organic EL element 618 is disposed within a space 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealing material 605. Note that the space 607 is filled with a filler material; in addition to inactive gases (nitrogen, argon, etc.), the sealing material can also be used as the filler. It is preferable to form a recess in the sealing substrate and place a desiccant therein to suppress deterioration caused by moisture.

[0507] Furthermore, epoxy resin and glass powder are preferably used as sealing materials 605. These materials are also preferably those that minimize the permeability of moisture and oxygen. In addition to glass substrates and quartz substrates, plastic substrates made of FRP (Fiber Reinf...

Claims

1. A light-emitting device, comprising: First electrode; Second electrode; Emissive layer; First hole transport layer; as well as First electron transport layer, The first electrode is located on the substrate and between the second electrode and the substrate. The light-emitting layer, the first hole transport layer, and the first electron transport layer are located between the first electrode and the second electrode. The light-emitting layer is located between the first hole transport layer and the first electron transport layer. The light-emitting layer and the first hole transport layer are in contact with each other. The GSP_slope (mV / nm) of one of the light-emitting layer and the first hole transport layer located on the second electrode side is smaller than the GSP_slope (mV / nm) of the other located on the first electrode side. Furthermore, the GSP_slope (mV / nm) is expressed as ΔV / Δd, where ΔV (mV) is the change in surface potential with respect to the change in thickness Δd (nm).

2. A light-emitting device, comprising: First electrode; Second electrode; Emissive layer; First hole transport layer; as well as First electron transport layer, The first electrode is located on the substrate and between the second electrode and the substrate. The light-emitting layer, the first hole transport layer, and the first electron transport layer are located between the first electrode and the second electrode. The light-emitting layer is located between the first hole transport layer and the first electron transport layer. The GSP_slope (mV / nm) of one of the light-emitting layers and the first electron transport layer located on the first electrode side is smaller than the GSP_slope (mV / nm) of the other located on the second electrode side. Furthermore, the GSP_slope (mV / nm) is expressed as ΔV / Δd, where ΔV (mV) is the change in surface potential with respect to the change in thickness Δd (nm).

3. The light-emitting device according to claim 2, The GSP_slope (mV / nm) of one of the light-emitting layer and the first hole transport layer located on the side of the second electrode is smaller than the GSP_slope (mV / nm) of the other located on the side of the first electrode.

4. The light-emitting device according to claim 1, further comprising: Second hole transport layer; as well as The second electron transport layer, The second hole transport layer and the second electron transport layer are located between the first electrode and the second electrode. The first hole transport layer is located between the second hole transport layer and the light-emitting layer. The first electron transport layer is located between the second electron transport layer and the light-emitting layer. The GSP_slope (mV / nm) of one of the first hole transport layers and the second hole transport layer located on the side of the second electrode is larger than the GSP_slope (mV / nm) of the other located on the side of the first electrode. Furthermore, the GSP_slope (mV / nm) of one of the first electron transport layers and the second electron transport layer located on the side of the first electrode is larger than the GSP_slope (mV / nm) of the other located on the side of the second electrode.

5. The light-emitting device according to claim 1, The difference between the GSP_slope (mV / nm) of the light-emitting layer and the GSP_slope (mV / nm) of the first hole transport layer is greater than 0mV / nm and less than 20mV / nm.

6. The light-emitting device according to claim 2, The difference between the GSP_slope (mV / nm) of the light-emitting layer and the GSP_slope (mV / nm) of the first electron transport layer is greater than or equal to 0 mV / nm and less than or equal to 20 mV / nm.

7. The light-emitting device according to claim 3, The difference between the GSP_slope (mV / nm) of the first hole transport layer and the GSP_slope (mV / nm) of the first electron transport layer is greater than 0 mV / nm and less than 20 mV / nm.

8. The light-emitting device according to claim 1, Wherein, at least one of the first hole transport layer and the first electron transport layer has a refractive index of 1.75 or less at the peak wavelength of the electroluminescence spectrum of the light-emitting device.

9. The light-emitting device according to claim 4, Wherein, at least one of the second hole transport layer and the second electron transport layer has a refractive index of 1.75 or less at the peak wavelength of the electroluminescence spectrum of the light-emitting device.

10. A light-emitting device, comprising: First electrode; Second electrode; Emissive layer; First hole transport layer; as well as First electron transport layer, The first electrode is located on the substrate and between the second electrode and the substrate. The light-emitting layer, the first hole transport layer, and the first electron transport layer are located between the first electrode and the second electrode. The first hole transport layer is located between the first electrode and the light-emitting layer. The first electron transport layer is located between the second electrode and the light-emitting layer. The light-emitting layer is in contact with the first hole transport layer. The light-emitting layer comprises a main material and a light-emitting substance. The first hole transport layer contains a first organic compound. The first electron transport layer contains a second organic compound. The GSP_slope (mV / nm) of the vapor-deposited film of the host material is smaller than that of the vapor-deposited film of the first organic compound. Furthermore, the GSP_slope (mV / nm) is expressed as ΔV / Δd, where ΔV (mV) is the change in surface potential with respect to the change in thickness Δd (nm).

11. The light-emitting device according to claim 10, The GSP_slope (mV / nm) of the vapor-deposited film of the host material is smaller than that of the vapor-deposited film of the second organic compound.

12. The light-emitting device according to claim 10, further comprising: Second hole transport layer; as well as The second electron transport layer, The second hole transport layer and the second electron transport layer are located between the first electrode and the second electrode. The first hole transport layer is located between the second hole transport layer and the light-emitting layer. The first electron transport layer is located between the second electron transport layer and the light-emitting layer. The second hole transport layer contains a third organic compound. The second electron transport layer contains a fourth organic compound. The GSP_slope (mV / nm) of the vapor-deposited film of the first organic compound is larger than that of the vapor-deposited film of the third organic compound. Furthermore, the GSP_slope (mV / nm) of the vapor-deposited film of the second organic compound is larger than that of the vapor-deposited film of the fourth organic compound.

13. The light-emitting device according to claim 10, The difference between the GSP_slope (mV / nm) of the vapor-deposited film of the host material and the GSP_slope (mV / nm) of the vapor-deposited film of the first organic compound is greater than or equal to 0 mV / nm and less than or equal to 20 mV / nm.

14. The light-emitting device according to claim 11, The difference between the GSP_slope (mV / nm) of the vapor-deposited film of the host material and the GSP_slope (mV / nm) of the vapor-deposited film of the second organic compound is greater than or equal to 0 mV / nm and less than or equal to 20 mV / nm.

15. The light-emitting device according to claim 12, The difference between the GSP_slope (mV / nm) of the vapor-deposited film of the first organic compound and the GSP_slope (mV / nm) of the vapor-deposited film of the second organic compound is greater than or equal to 0 mV / nm and less than or equal to 20 mV / nm.

16. The light-emitting device according to claim 10, Wherein, at least one of the films of the first organic compound and the second organic compound has a refractive index of 1.75 or less at the peak wavelength of the electroluminescence spectrum of the light-emitting device.

17. The light-emitting device according to claim 10, At least one of the first organic compound and the second organic compound has at least one group selected from alkyl groups having 2 to 10 carbon atoms and cycloalkyl groups having 6 to 12 carbon atoms.

18. The light-emitting device according to claim 12, The refractive index of the film of the third organic compound is below 1.75 at the peak wavelength of the electroluminescence spectrum of the light-emitting device.

19. The light-emitting device according to claim 12, At least one of the third organic compound and the fourth organic compound has at least one group selected from alkyl groups having 2 to 10 carbon atoms and cycloalkyl groups having 6 to 12 carbon atoms.

20. The light-emitting device according to claim 10, The luminescent material mentioned therein is a fluorescent luminescent material.

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