Light emitting device, display device, display module, and electronic apparatus

Abstract

Provided is a novel light-emitting device having excellent convenience, usefulness, or reliability. The light emitting device includes a first light source and a first conversion unit, the first light source overlapping the first conversion unit, the first light source irradiating a first light to the first conversion unit, the first light having a spectrum having an intensity in a region of a first wavelength. The first conversion unit includes a first layer and a second layer, the first layer is sandwiched between the second layer and the first light source, and the first layer converts the first light into the second light. The first light has a spectrum having a peak at a first wavelength, the second light has a spectrum having a peak at a second wavelength, the second wavelength is longer than the first wavelength, the second layer has a reflectance of 0.8-1.0 with respect to a wave of the first wavelength, and the second layer has a transmittance of 0.8-1.0 with respect to a wave of the second wavelength.

Description

TECHNICAL FIELD

[0001] One embodiment of the present application relates to a display device, a display module, an electronic device, or a semiconductor device.

[0002] Note that one embodiment of the present application is not limited to the technical field described above. The technical field of one embodiment of the present application disclosed in this specification and the like relates to an object, a method, or a manufacturing method. In addition, one embodiment of the present application relates to a process, a machine, manufacture, or a composition of matter. Thus, more specifically, examples of the technical field of one embodiment of the present application disclosed in this specification include a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, a driving method thereof, and a manufacturing method thereof. BACKGROUND

[0003] For example, a display device including a first quantum dot layer that converts the wavelength of light emitted from a first light-emitting element, a second quantum dot layer that converts the wavelength of light emitted from a second light-emitting element, and a light-reducing film that reduces external light incident on the first quantum dot layer and the second quantum dot layer, and in which no color filter and no quantum dot layer are formed in a blue sub-pixel is known (Patent Document 1).

[0004] [Prior Art Document]

[0005] [Patent Document]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2021-21875 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] As described above, although various inventions are disclosed in the prior art document, there are many problems in convenience, practicality, or reliability, and thus the inventions are not satisfactory. In view of this, one of objects of one embodiment of the present application is to provide a novel light-emitting device which is high in convenience, practicality, or reliability. Furthermore, one of objects of one embodiment of the present application is to provide a novel display device which is high in convenience, practicality, or reliability. Furthermore, one of objects of one embodiment of the present application is to provide a novel display module which is high in convenience, practicality, or reliability. Furthermore, one of objects of one embodiment of the present application is to provide a novel electronic device which is high in convenience, practicality, or reliability. Furthermore, one of objects of one embodiment of the present application is to provide a novel light-emitting device, a novel display device, a novel display module, a novel electronic device, or a novel semiconductor device.

[0009] Note that the description of these objects does not preclude the presence of other objects. Note that one embodiment of the present application does not necessarily achieve all the objects. Furthermore, an object other than those described above can be extracted from the description, drawings, claims, and the like.

[0010] Means of solving the technical problem

[0011] (1) One embodiment of the present application is a light-emitting device including a first light source and a first conversion unit.

[0012] The first light source overlaps with the first conversion unit. The first light source irradiates the first conversion unit with first light, and the first light has a spectrum that has intensity in a region of a first wavelength.

[0013] The first conversion unit includes a first layer and a second layer.

[0014] The first layer is interposed between the second layer and the first light source, and the first layer converts the first light into second light.

[0015] The second light has a spectrum that has a peak at a second wavelength, and the second wavelength is longer than the first wavelength.

[0016] The second layer has a reflectance of 0.8 or more and 1.0 or less for a wave of the first wavelength, and has a transmittance of 0.8 or more and 1.0 or less for a wave of the second wavelength.

[0017] Thus, the first layer can convert the first light emitted from the first light source into the second light. In addition, the second layer can reflect the first light that has reached the second layer through the first layer toward the first layer. In addition, the first layer can convert the first light reflected by the second layer into the second light. Furthermore, the first light emitted from the first light source can be efficiently converted into the second light. Furthermore, for example, blue light can be efficiently converted into green light or red light. As a result, a novel light-emitting device with high convenience, utility, or reliability can be provided.

[0018] (2) Furthermore, one embodiment of the present application is the above light-emitting device in which the first layer includes a quantum dot.

[0019] Thus, the first layer can convert the first light emitted from the first light source into the second light having a spectrum with a narrow full width at half maximum. In addition, the first light emitted from the first light source can be converted into the second light with high chromaticity. As a result, a novel light-emitting device with high convenience, utility, or reliability can be provided.

[0020] (3) Furthermore, one embodiment of the present application is the above light-emitting device in which the second layer includes a third layer, a fourth layer, and a fifth layer.

[0021] The fourth layer has a refractive index of less than 1.6 for the first wavelength when the fourth layer is in a film state, and the third layer and the fifth layer each have a refractive index of 1.6 or more for the first wavelength when the third layer and the fifth layer are in a film state.

[0022] The third layer and the fifth layer each have a refractive index of less than 1.6 for the first wavelength when the third layer and the fifth layer are in a film state, and the fourth layer has a refractive index of 1.6 or more for the first wavelength when the fourth layer is in a film state.

[0023] Thus, the second layer can constitute a dielectric multilayer film. In addition, the second layer can have a prescribed reflectance for the first wavelength and a prescribed transmittance for the second wavelength. As a result, a novel light-emitting device having high convenience, utility, or reliability can be provided.

[0024] (4) Furthermore, one embodiment of the present application is the above-described light-emitting device in which the first conversion unit includes a sixth layer.

[0025] The sixth layer is interposed between the first layer and the first light source. The sixth layer has a transmittance of 0.8 or more and 1.0 or less for the first wavelength, and the sixth layer has a reflectance of 0.8 or more and 1.0 or less for the second wavelength.

[0026] Thus, the sixth layer can reflect the second light that has reached the sixth layer through the first layer, toward the first layer. Furthermore, the second light can be extracted from the light-emitting device with high efficiency. Furthermore, the first light emitted by the first light source can be converted into the second light with high efficiency. As a result, a novel light-emitting device having high convenience, utility, or reliability can be provided.

[0027] (5) Furthermore, one embodiment of the present application is the above-described light-emitting device in which the sixth layer includes a seventh layer, an eighth layer, and a ninth layer.

[0028] The eighth layer is interposed between the seventh layer and the ninth layer. The seventh layer and the ninth layer each have a refractive index of 1.6 or more for the second wavelength when the seventh layer and the ninth layer are in a film state, and the eighth layer has a refractive index of less than 1.6 for the second wavelength when the eighth layer is in a film state.

[0029] The seventh layer and the ninth layer each have a refractive index of less than 1.6 for the second wavelength when the seventh layer and the ninth layer are in a film state, and the eighth layer has a refractive index of 1.6 or more for the second wavelength when the eighth layer is in a film state.

[0030] Thus, the sixth layer can constitute a dielectric multilayer film. In addition, the sixth layer can have a prescribed transmittance for the first wavelength and a prescribed reflectance for the second wavelength. As a result, a novel light-emitting device having high convenience, utility, or reliability can be provided.

[0031] (6) In addition, one embodiment of the present application is the above-described light-emitting device, in which the first conversion unit includes a tenth layer.

[0032] The second layer is interposed between the tenth layer and the first light source. The tenth layer has a transmittance of greater than 0 and less than or equal to 0.2 for a wave of the first wavelength, and the tenth layer has a transmittance of greater than or equal to 0.6 and less than or equal to 1.0 for a wave of the second wavelength.

[0033] Thus, the second light can be extracted from the light-emitting device without mixing of the first light. In addition, for example, green light with high chroma or red light with high chroma can be extracted from the light-emitting device without mixing of blue light. Furthermore, a part of external light can be absorbed by the tenth layer. In addition, external light reaching the second layer can be reduced. In addition, external light reflected by the second layer can be reduced. As a result, a novel light-emitting device with high convenience, utility, or reliability can be provided.

[0034] (7) One embodiment of the present application is a display device including a set of pixels, in which the set of pixels includes a first pixel, a second pixel, and a third pixel.

[0035] The first pixel includes a first light-emitting device and a first pixel circuit, and the first light-emitting device is electrically connected to the first pixel circuit.

[0036] The second pixel includes a second light-emitting device and a second pixel circuit, and the second light-emitting device is electrically connected to the second pixel circuit.

[0037] The third pixel includes a third light-emitting device and a third pixel circuit, and the third light-emitting device is electrically connected to the third pixel circuit.

[0038] The first light-emitting device includes a second light source and a second conversion unit, the second light source overlaps with the second conversion unit, the second light source irradiates the second conversion unit with first light, and the first light has an emission spectrum including blue light.

[0039] The second conversion unit includes an eleventh layer and a twelfth layer, and the eleventh layer is interposed between the twelfth layer and the second light source.

[0040] The eleventh layer converts the first light into third light, and the third light has an emission spectrum including red light.

[0041] The twelfth layer has a reflectance of greater than or equal to 0.8 and less than or equal to 1.0 for the first light, and the twelfth layer has a transmittance of greater than or equal to 0.8 and less than or equal to 1.0 for the third light.

[0042] The second light-emitting device includes a third light source and a third conversion unit, the third light source overlaps with the third conversion unit, and the third light source irradiates the third conversion unit with the first light.

[0043] The third conversion unit includes a thirteenth layer and a fourteenth layer, with the thirteenth layer sandwiched between the fourteenth layer and the third light source.

[0044] The thirteenth layer converts the first light into the fourth light, which has an emission spectrum that includes green light.

[0045] The fourteenth layer has a reflectivity of 0.8 or higher and 1.0 or lower for the first light, and a transmittance of 0.8 or higher and 1.0 or lower for the fourth light.

[0046] The third light-emitting device includes a fourth light source, which emits the first light.

[0047] Therefore, the second, third, and fourth light sources can adopt the same structure. Furthermore, the second, third, and fourth light sources can be manufactured using the same manufacturing process. Furthermore, the manufacturing process of the display device can be simplified. Furthermore, the first light can be efficiently converted into the third light. Furthermore, the first light can be efficiently converted into the fourth light. Furthermore, for example, blue light can be efficiently converted into green or red light. As a result, a novel display device with good convenience, practicality, and reliability can be provided.

[0048] (8) In addition, one aspect of the present invention is the above-described display device, wherein the eleventh layer contains quantum dots and the thirteenth layer also contains quantum dots.

[0049] (9) In addition, one aspect of the present invention is the above-described light-emitting device, wherein the second conversion unit includes a fifteenth layer.

[0050] The fifteenth layer is sandwiched between the eleventh layer and the second light source. The fifteenth layer has a transmittance of 0.8 or more and less than 1.0 for the first light, and a reflectance of 0.8 or more and less than 1.0 for red light.

[0051] Therefore, the fifteenth layer can reflect the third light that has passed through the eleventh layer back to the eleventh layer. Furthermore, the third light can be efficiently extracted from the light-emitting device. Additionally, the first light emitted by the second light source can be efficiently converted into the third light. As a result, a novel display device with good convenience, practicality, and reliability can be provided.

[0052] (10) In addition, one aspect of the present invention is the above-described display device, wherein the second conversion unit includes a sixteenth layer.

[0053] The sixteenth layer has a transmittance of greater than 0 and less than 0.2 for the first light, and a transmittance of greater than 0.6 and less than 1.0 for the red light.

[0054] Therefore, for example, bright red light can be efficiently converted. Bright red can be displayed efficiently. Furthermore, a portion of the external light can be absorbed using the sixteenth layer. Additionally, the amount of external light reaching the twelfth layer can be reduced. Furthermore, the amount of external light reflected by the twelfth layer can be reduced. As a result, a novel display device with good convenience, practicality, and reliability can be provided.

[0055] (11) In addition, one aspect of the present invention is the above-described light-emitting device, wherein the third conversion unit includes a seventeenth layer.

[0056] The seventeenth layer is sandwiched between the thirteenth layer and the third light source. The seventeenth layer has a transmittance of 0.8 or higher and 1.0 or lower for the first light, and a reflectance of 0.8 or higher and 1.0 or lower for green light.

[0057] Therefore, the seventeenth layer can reflect the fourth light, which has passed through the thirteenth layer and reached the seventeenth layer, back to the thirteenth layer. Furthermore, the fourth light can be efficiently extracted from the light-emitting device. Additionally, the first light emitted by the third light source can be efficiently converted into the fourth light. As a result, a novel display device with good convenience, practicality, and reliability can be provided.

[0058] (12) In addition, one aspect of the present invention is the above-described display device, wherein the third conversion unit includes an eighteenth layer.

[0059] The eighteenth layer has a transmittance of greater than 0 and less than 0.2 for the first light, and a transmittance of greater than 0.6 and less than 1.0 for green light.

[0060] Therefore, for example, it is possible to efficiently convert light into a bright green color. Furthermore, a bright green color can be displayed. Additionally, a portion of the external light can be absorbed using the eighteenth layer. Furthermore, the amount of external light reaching the fourteenth layer can be reduced. Additionally, the amount of external light reflected by the fourteenth layer can be reduced. As a result, a novel display device with good convenience, practicality, and reliability can be provided.

[0061] (13) In addition, one aspect of the present invention is the above-described display device, wherein the third light-emitting device includes a fourth conversion unit.

[0062] The fourth light source overlaps with the fourth conversion unit. The fourth light source illuminates the fourth conversion unit with first light, which has an emission spectrum that includes both blue and green light.

[0063] The fourth conversion unit includes a nineteenth layer. The nineteenth layer has a transmittance of greater than 0 and less than 0.2 for green light, and a transmittance of greater than 0.6 and less than 1.0 for blue light.

[0064] This allows for the display of a bright blue color. As a result, a novel display device with good convenience, practicality, and reliability can be provided.

[0065] (14) In addition, one aspect of the present invention is the above-described display device, wherein a set of pixels includes a fourth pixel, the fourth pixel includes a fifth light source, and the fifth light source emits a first light.

[0066] Therefore, a fourth pixel can be used to display blue light. Alternatively, for example, a hue between blue and green can be displayed. Alternatively, for example, a hue between blue and red can be displayed. Furthermore, for example, white can be displayed. Additionally, the energy efficiency of the display device can be improved. As a result, a novel display device with good convenience, practicality, and reliability can be provided.

[0067] (15) In addition, one aspect of the present invention is a display module comprising: the above-described display device; and at least one of a connector and an integrated circuit.

[0068] (16) In addition, one aspect of the present invention is an electronic device comprising: the above-described display device; and at least one of a battery, a camera, a speaker, and a microphone.

[0069] In the accompanying drawings of this specification, the constituent elements are shown as independent blocks according to their functions. However, in reality, it is difficult to completely divide the constituent elements according to their functions, and a constituent element may involve multiple functions.

[0070] In this specification, a light-emitting device includes an image display device that uses a light-emitting element. Furthermore, a light-emitting device sometimes includes modules such as: modules in which the light-emitting element is mounted with connectors such as anisotropic conductive film (ACF) or TCP (Tape Carrier Package); modules in which a printed circuit board is provided at the end of the TCP; or modules in which an IC (integrated circuit) is directly mounted on the light-emitting element via COG (Chip On Glass) packaging. Moreover, lighting devices and the like sometimes include light-emitting devices.

[0071] Invention Effects

[0072] According to one aspect of the present invention, a novel light-emitting device with good convenience, practicality, or reliability can be provided. Furthermore, according to one aspect of the present invention, a novel display device with good convenience, practicality, or reliability can be provided. Furthermore, according to one aspect of the present invention, a novel display module with good convenience, practicality, or reliability can be provided. Furthermore, according to one aspect of the present invention, a novel electronic device with good convenience, practicality, or reliability can be provided. Furthermore, a novel display device can be provided. Furthermore, a novel light-emitting device can be provided. Furthermore, a novel display device can be provided. Furthermore, a novel display module can be provided. Furthermore, a novel electronic device can be provided.

[0073] Note that the description of these effects does not preclude the existence of other effects. Furthermore, one embodiment of the invention does not necessarily require all of the aforementioned effects. Note that effects other than those described above can be understood and extracted from the specification, drawings, claims, etc. Attached Figure Description

[0074] Figure 1 This is a diagram illustrating the structure of the light-emitting device according to an embodiment.

[0075] Figures 2A-2D This is a diagram illustrating the structure of the light-emitting device according to an embodiment.

[0076] Figure 3A and Figure 3B This is a diagram illustrating the structure of the light-emitting device according to an embodiment.

[0077] Figure 4 This is a diagram illustrating the structure of the light source according to the embodiment.

[0078] Figure 5A and Figure 5B This is a diagram illustrating the structure of the light source according to the embodiment.

[0079] Figure 6 This is a diagram illustrating the structure of the light source according to the embodiment.

[0080] Figure 7A and Figure 7B This is a diagram illustrating the structure of a display device according to an embodiment.

[0081] Figure 8A and Figure 8B This is a diagram illustrating the structure of a display device according to an embodiment.

[0082] Figures 9A-9D This is a diagram illustrating the structure of a display device according to an embodiment.

[0083] Figures 10A-10DThis is a diagram illustrating the structure of a display device according to an embodiment.

[0084] Figure 11A and Figure 11B This is a diagram illustrating the structure of a display device according to an embodiment.

[0085] Figures 12A-12C This is a diagram illustrating the structure of a display device according to an embodiment.

[0086] Figure 13 This is a diagram illustrating the structure of a display device according to an embodiment.

[0087] Figure 14 This is a diagram illustrating the structure of the display module according to the implementation method.

[0088] Figure 15 This is a diagram illustrating the structure of a display device according to an embodiment.

[0089] Figure 16 This is a diagram illustrating the structure of a display device according to an embodiment.

[0090] Figure 17 This is a diagram illustrating the structure of a display device according to an embodiment.

[0091] Figure 18 This is a diagram illustrating the structure of a display device according to an embodiment.

[0092] Figure 19 This is a diagram illustrating the structure of a display device according to an embodiment.

[0093] Figure 20 This is a diagram illustrating the structure of a display device according to an embodiment.

[0094] Figure 21 This is a diagram illustrating the structure of the display module according to the implementation method.

[0095] Figures 22A-22C This is a diagram illustrating the structure of a display device according to an embodiment.

[0096] Figure 23 This is a diagram illustrating the structure of a display device according to an embodiment.

[0097] Figure 24 This is a diagram illustrating the structure of a display device according to an embodiment.

[0098] Figure 25 This is a diagram illustrating the structure of a display device according to an embodiment.

[0099] Figure 26 This is a diagram illustrating the structure of a display device according to an embodiment.

[0100] Figure 27 This is a diagram illustrating the structure of a display device according to an embodiment.

[0101] Figures 28A-28D This is a diagram illustrating an example of an electronic device according to an embodiment.

[0102] Figures 29A-29F This is a diagram illustrating an example of an electronic device according to an embodiment.

[0103] Figures 30A-30G This is a diagram illustrating an example of an electronic device according to an embodiment. Detailed Implementation

[0104] One aspect of the present invention provides a light-emitting device comprising a first light source and a first conversion unit. The first light source overlaps with the first conversion unit, and the first light source irradiates the first conversion unit with first light, the first light having a spectrum with intensity in the region of a first wavelength. The first conversion unit comprises a first layer and a second layer, the first layer being sandwiched between the second layer and the first light source. The first layer converts the first light into second light, the second light having a spectrum with a peak at a second wavelength. The second wavelength is longer than the first wavelength, and the second layer has a reflectivity of 0.8 or more and 1.0 or less for the first wavelength, and a transmittance of 0.8 or more and 1.0 or less for the second wavelength.

[0105] Therefore, the first layer can convert the first light emitted by the first light source into second light. Furthermore, the second layer can reflect the first light that has passed through the first layer back to the second layer. Additionally, the first layer can convert the first light reflected by the second layer into second light. Furthermore, the first light emitted by the first light source can be efficiently converted into second light. Furthermore, for example, blue light can be efficiently converted into green or red light. As a result, a novel light-emitting device with good convenience, practicality, and reliability can be provided.

[0106] The embodiments will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the following description, and those skilled in the art will readily understand that its methods and details can be varied in many ways without departing from the spirit and scope of the invention. Therefore, the present invention should not be construed as being limited only to the contents described in the embodiments shown below. Note that in the inventive structures described below, the same reference numerals are used in different drawings to denote the same parts or parts having the same function, and repeated descriptions are omitted.

[0107] (Implementation Method 1)

[0108] In this embodiment, refer to Figures 1-3B The structure of a light-emitting device according to one aspect of the present invention is described.

[0109] Figure 1 This is a cross-sectional view illustrating the structure of a light-emitting device according to one aspect of the present invention.

[0110] Figure 2A This is a diagram illustrating the emission spectrum of a light-emitting device according to one aspect of the present invention. Furthermore, Figure 2B and Figure 2C These are graphs illustrating the wavelength-transmittance and wavelength-reflectance characteristics of a light-emitting device according to one aspect of the present invention. Figure 2D This is a graph illustrating the wavelength-transmittance characteristics of a light-emitting device according to one aspect of the present invention.

[0111] <Structure Example 1 of the 550X Light-Emitting Device>

[0112] One aspect of the present invention is a light-emitting device comprising a light source LSX and a conversion unit CUX (see reference). Figure 1 ).

[0113] <Structural Example of a Light Source LSX>

[0114] The light source LSX overlaps with the conversion unit CUX, and the light source LSX illuminates the conversion unit CUX with light LL. Light LL has a spectrum with intensity in the region of wavelength λL (see reference). Figure 2A In other words, light LL contains light with wavelength λL.

[0115] For example, light-emitting diodes (LEDs) can be used in light sources such as LSX. This allows for high reliability, high brightness, and high current efficiency.

[0116] Furthermore, for example, an organic light-emitting diode (OLED) can be used in the light source LSX. This allows the light source to be expanded into a planar shape. Additionally, the area of ​​the light source can be increased. Note that a detailed structure suitable for the light source LSX is described in detail in Embodiment 2.

[0117] The light LL contains blue light. For example, the light LL includes light with wavelengths above 380 nm and below 480 nm, preferably having a spectrum with a maximum peak in the range of above 380 nm and below 480 nm.

[0118] Furthermore, the light LL can also contain both blue and green light. Alternatively, the light LL can also contain blue, green, and red light. This allows for the easy selection of materials relevant to the light emission of the light source LSX. Furthermore, the luminous efficiency of the light source LSX can be improved.

[0119] <Example 1 of the structure of a conversion unit CUX>

[0120] The conversion unit CUX includes layer CCX and layer DMX1 (see reference). Figure 1 The CCX layer is sandwiched between the DMX1 layer and the light source LSX.

[0121] <<Example 1 of a layered CCX structure>>

[0122] The CCX layer has the function of converting light LL into light LX. Light LX has a spectrum with a peak at wavelength λX, which is longer than wavelength λL (see reference). Figure 2A In other words, layer CCX converts light of wavelength λL, which is included in light LL, into light of wavelength λX, which is longer than wavelength λL. Note that the spectrum of light LX has a peak at wavelength λX.

[0123] For example, phosphors can be used in layered CCX.

[0124] <<Example 1 of Layer DMX1 Structure>>

[0125] Layer DMX1 has a reflectivity of 0.8 or higher and 1.0 or lower for wavelengths λL (refer to...). Figure 2B Furthermore, layer DMX1 has a transmittance of 0.8 or higher and 1.0 or lower for wavelength λX. Note that the closer the reflectance of layer DMX1 is to wavelength λL, the better; below 0.8, the loss of LX becomes significant. Additionally, the closer the transmittance of layer DMX1 is to wavelength λX, the better; below 0.8, the loss of LX becomes more significant.

[0126] Therefore, layer CCX can convert the light LL emitted by light source LSX into light LX. Additionally, layer DMX1 can reflect the light LL that passes through layer CCX and reaches layer DMX1 back to layer CCX. Furthermore, layer CCX can convert the light LL reflected by layer DMX1 into light LX. Moreover, the light LL emitted by light source LSX can be efficiently converted into light LX. Furthermore, for example, blue light can be efficiently converted into green or red light. As a result, a novel light-emitting device with good convenience, practicality, and reliability can be provided.

[0127] <<Example 2 of a Layered CCX Structure>>

[0128] Layered CCXs may contain quantum dots (QDs). Quantum dots have diameters ranging from several nanometers to tens of nanometers and contain semiconductor crystals. For example, cadmium sulfide (CdS) and indium phosphide (InP) can be used for semiconductor crystal formation.

[0129] Therefore, the CCX layer can convert the light LL emitted by the light source LSX into light LX with a narrow full width at half maximum (FWHM) spectrum. Furthermore, it can convert the light LL emitted by the light source LSX into light LX with high chroma. As a result, a novel light-emitting device with good convenience, practicality, and reliability can be provided.

[0130] <<Example 2 of Layer DMX1 Structure>>

[0131] For example, layer DMX1 includes layer DMX11, layer DMX12, and layer DMX13 (see reference). Figure 3A Layer DMX12 is sandwiched between layers DMX11 and DMX13. Layer DMX1 comprises three or more layers, preferably five or more layers. This allows for a reflectivity of 0.8 or higher at a specified wavelength. Furthermore, it allows for a transmittance of 0.8 or higher at other specified wavelengths. Note that the more layers there are, the higher the reflectivity can be, and the narrower the full width at half maximum (FWHM) of the bandpass filter can be achieved.

[0132] When layer DMX12, in its film state, has a refractive index of less than 1.6 for wavelength λL, layers DMX11 and DMX13, both in their film state, have a refractive index of 1.6 or higher for wavelength λL. Note that when using 1.6 as an indicator to distinguish between materials with high and low refractive indices in their film state, two or more materials with different refractive indices can be easily selected from the group of materials available for industrial applications. Note that in this specification, the refractive index for wavelength λL in its film state is equivalent to the value measured using a spectroscopic ellipsometry on a sample of a target layer (e.g., a layer relative to layer DMX12) deposited on a Si wafer.

[0133] For example, silicon oxide (SiO2), magnesium fluoride (MgF2), lithium fluoride (LiF), or sodium fluoride (NaF) can be used as materials with a refractive index of less than 1.6 in the film state.

[0134] In addition, for example, materials with a refractive index of 1.6 or higher can be used in the film state, such as titanium oxide, silicon nitride (SiNx: x is any number greater than 0), aluminum oxide, zirconium oxide or hafnium oxide.

[0135] When layer DMX12 is in the film state and has a refractive index greater than 1.6 for wavelength λL, layers DMX11 and DMX13, when both are in the film state, have a refractive index less than 1.6 for wavelength λL.

[0136] Therefore, layer DMX1 can constitute a dielectric multilayer film. Furthermore, layer DMX1 can have a specified reflectivity for wavelength λL and a specified transmittance for wavelength λX. As a result, a novel light-emitting device with good convenience, practicality, and reliability can be provided.

[0137] <Example 2 of the structure of the conversion unit CUX>

[0138] The conversion unit CUX includes layer DMX2 (see reference). Figure 1 Layer DMX2 is sandwiched between layer CCX and the light source LSX.

[0139] <<Example 1 of Layer DMX2 Structure>>

[0140] Layer DMX2 has a transmittance of 0.8 or higher and 1.0 or lower for wavelength λL (refer to...). Figure 2C Layer DMX2 has a reflectivity of 0.8 or higher and 1.0 or lower for wavelength λX.

[0141] Therefore, layer DMX2 can reflect the light LX that has passed through layer CCX and reached layer DMX2 back to layer CCX. Furthermore, light LX can be efficiently extracted from the light-emitting device. In addition, the light LL emitted by the light source LSX can be efficiently converted into light LX. As a result, a novel light-emitting device with good convenience, practicality, and reliability can be provided.

[0142] <<Example 2 of Layer DMX2 Structure>>

[0143] For example, layer DMX2 includes layers DMX21, DMX22, and DMX23 (see reference). Figure 3B Layer DMX22 is sandwiched between layers DMX21 and DMX23. Layer DMX2 comprises three or more layers, preferably five or more layers. This allows for a reflectivity of 0.8 or higher at a specified wavelength. Furthermore, it allows for a transmittance of 0.8 or higher at other specified wavelengths. Note that the more layers there are, the higher the reflectivity can be, and the narrower the full width at half maximum (FWHM) of the bandpass filter can be achieved.

[0144] When layer DMX22 is in the film state, it has a refractive index of less than 1.6 for wavelength λX, while layers DMX21 and DMX23 are both in the film state, they have a refractive index of more than 1.6 for wavelength λX.

[0145] When layer DMX22 is in the film state and has a refractive index greater than 1.6 for wavelength λX, layers DMX21 and DMX23, when both are in the film state, have a refractive index less than 1.6 for wavelength λX.

[0146] Therefore, layer DMX2 can constitute a dielectric multilayer film. Furthermore, layer DMX2 can have a specified transmittance for wavelength λL and a specified reflectance for wavelength λX. As a result, a novel light-emitting device with good convenience, practicality, and reliability can be provided.

[0147] <Example 3 of the structure of the conversion unit CUX>

[0148] The conversion unit CUX includes the layer CFX (see reference). Figure 1 Layer DMX1 is sandwiched between layer CFX and the light source LSX.

[0149] <<Example of Layered CFX Structure>>

[0150] Layer CFX has a transmittance greater than 0 and less than 0.2 for wavelengths λL (refer to...). Figure 2D Furthermore, layer CFX has a transmittance of 0.6 to 1.0 for wavelength λX. Note that the closer the transmittance of layer CFX is to wavelength λL, the better, as light LL leaks from the light-emitting device when it is above 0.2. Additionally, the closer the transmittance of layer CFX is to wavelength λX, the better, as the effectiveness of extracting light LX from the light-emitting device decreases when it is below 0.6. Moreover, external light reflection can be suppressed; the full width at half maximum (FWHM) of the reflection spectrum of layer DMX2 is narrower than that of the transmission spectrum of layer CFX.

[0151] Therefore, the mixing of light LL can be suppressed, and light LX can be extracted from the light-emitting device. Furthermore, for example, the mixing of blue light can be prevented, and high-chroma green light, high-chroma red light, or high-chroma red light can be extracted from the light-emitting device. Additionally, a portion of the external light can be absorbed using layer CFX. Furthermore, the amount of external light reaching layer DMX1 can be reduced. Additionally, the amount of external light reflected by layer DMX1 can be reduced. As a result, a novel light-emitting device with good convenience, practicality, and reliability can be provided.

[0152] Note that this embodiment can be appropriately combined with other embodiments shown in this specification.

[0153] (Implementation Method 2)

[0154] In this embodiment, refer to Figure 4 The structure of the light source LSX of a light-emitting device that can be used in one aspect of the present invention is described.

[0155] Figure 4 This is a cross-sectional view illustrating the structure of the light source LSX of a display device that can be used in one aspect of the present invention.

[0156] The structure of the light source LSX described in this embodiment can be used in a display device according to one aspect of the present invention. Specifically, the symbol "X" for the structure of the light source LSX can be replaced with "A" to describe the light source LSA. Similarly, "X" can be replaced with "B" or "C" to apply the structure of the light source LSX to the light source LSB or light source LSC.

[0157] <Structural Example of a Light Source LSX>

[0158] The light source LSX described in this embodiment includes electrode 551X, electrode 552X, and unit 103X. Electrode 552X overlaps with electrode 551X, and unit 103X is sandwiched between electrode 552X and electrode 551X.

[0159] <Structural Example of Unit 103X>

[0160] Unit 103X has a single-layer structure or a multi-layer structure. For example, unit 103X includes layer 111X, layer 112X, and layer 113X (see reference). Figure 4 Unit 103X has the function of emitting light LL.

[0161] Layer 111X is sandwiched between layers 113X and 112X, layer 113X is sandwiched between electrode 552X and layer 111X, and layer 112X is sandwiched between layer 111X and electrode 551X.

[0162] For example, a layer selected from functional layers such as a light-emitting layer, a hole transport layer, an electron transport layer, and a carrier blocking layer can be used in cell 103X. Furthermore, a layer selected from functional layers such as a hole injection layer, an electron injection layer, an exciton blocking layer, and a charge generation layer can be used in cell 103X.

[0163] <<Example of a Layer 112X Structure>>

[0164] For example, a hole-transporting material can be used for layer 112X. Furthermore, layer 112X can be referred to as a hole transport layer. Note that it is preferable to use a material whose band gap is larger than that of the luminescent material in layer 111X for layer 112X. Therefore, energy transfer from excitons generated in layer 111X to layer 112X can be suppressed.

[0165] Hole-transporting materials

[0166] The hole mobility can be 1×10 -6 cm 2 Materials with a value of / Vs or higher are appropriately used for hole transport materials.

[0167] For example, amine compounds or organic compounds with π-electron-rich heteroaromatic ring skeletons can be used in hole-transporting materials. Specifically, compounds with aromatic amine skeletons, carbazole skeletons, thiophene skeletons, furan skeletons, etc., can be used. In particular, compounds with aromatic amine skeletons or carbazole skeletons are preferred because they exhibit good reliability and high hole transport properties and help reduce the driving voltage.

[0168] As compounds with an aromatic amine skeleton, for example, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminebiphenyl (abbreviated as TPD), N,N'-bis(9,9'-spirobis[9H-fluorene]-2-yl)-N,N'-diphenyl-4,4'-diaminebiphenyl (abbreviated as BSPB), 4-phenyl-4'-(9-phenylfluorene-9-yl)triphenylamine (abbreviated as BPAFLP), 4-phenyl-3'-(9-phenylfluorene-9-yl)triphenylamine (abbreviated as mBPAFLP), and 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as PCB) can be used. A1BP), 4,4'-diphenyl-4”-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCBANB), 4,4'-di(1-naphthyl)-4”-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCCNBB), 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: PCBASF), etc.

[0169] Compounds with a carbazole skeleton can be used, for example, 1,3-bis(N-carbazole)benzene (mCP), 4,4'-bis(N-carbazole)biphenyl (CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (CzTP), 3,3'-bis(9-phenyl-9H-carbazole) (PCCP), etc.

[0170] As compounds with a thiophene skeleton, examples include 4,4',4”-(benzyl-1,3,5-triyl)tris(dibenzothiophene) (abbreviated as DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluorene-9-yl)phenyl]dibenzothiophene (abbreviated as DBTFLP-III), and 4-[4-(9-phenyl-9H-fluorene-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as DBTFLP-IV).

[0171] As compounds with a furan skeleton, for example, 4,4',4”-(benzyl-1,3,5-triyl)tris(dibenzofuran) (abbreviated as DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluorene-9-yl)phenyl]phenyl}dibenzofuran (abbreviated as mmDBFFLBi-II) can be used.

[0172] <<Example of a Layer 113X Structure>>

[0173] For example, electron transport materials, materials with an anthracene framework, and mixed materials can be used for layer 113X. Furthermore, layer 113X can be referred to as an electron transport layer. Note that it is preferable to use a material whose band gap is larger than that of the luminescent material in layer 111X for layer 113X. Therefore, energy transfer from excitons generated in layer 111X to layer 113X can be suppressed.

[0174] Electron transport materials

[0175] For example, the following material can be appropriately used as an electron transport material: having an electron mobility of 1 × 10⁻⁶ under an electric field strength V / cm square root of 600. -7 cm 2 / Vs or more and 5×10 -5 cm 2 Materials with a value of / Vs or less. This allows control over the electron transport properties in the electron transport layer. Furthermore, it allows control over the amount of electrons injected into the luminescent layer. Additionally, it prevents the luminescent layer from becoming overloaded with electrons.

[0176] For example, metal complexes or organic compounds with π-electron-deficient heteroaromatic ring skeletons can be used in electron transport materials.

[0177] As metal complexes, for example, bis(10-hydroxybenzo[h]quinoline)beryllium(II) (abbreviated as BeBq2), bis(2-methyl-8-hydroxyquinoline)(4-phenylphenol)aluminum(III) (abbreviated as BAlq), bis(8-hydroxyquinoline)zinc(II) (abbreviated as Znq), bis[2-(2-benzoxazolyl)phenol]zinc(II) (abbreviated as ZnPBO), bis[2-(2-benzothiazolyl)phenol]zinc(II) (abbreviated as ZnBTZ), etc.

[0178] Organic compounds with a π-electron-deficient heterocyclic ring skeleton can be used, for example, heterocyclic compounds with a polyazole skeleton, heterocyclic compounds with a diazine skeleton, heterocyclic compounds with a pyridine skeleton, and heterocyclic compounds with a triazine skeleton. In particular, heterocyclic compounds with a diazine skeleton or a pyridine skeleton are preferred due to their good reliability. Furthermore, heterocyclic compounds with a diazine (pyrimidine or pyrazine) skeleton exhibit high electron transport properties, thereby reducing the driving voltage.

[0179] As heterocyclic compounds with a polyazole skeleton, examples include 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated as PBD), 3-(4-biphenyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviated as TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]phenyl (abbreviated as OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviated as CO11), 2,2',2”-(1,3,5-phenyltriyl)tris(1-phenyl-1H-benzimidazole) (abbreviated as TPBI), and 2-[3-(dibenzothiophene-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviated as mDBTBIm-II), etc.

[0180] As heterocyclic compounds with a diazine skeleton, 2-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as: 2mDBTPDBq-II), 2-[3-(3'-dibenzothiophene-4-yl)biphenyl]dibenzo[f,h]quinoxaline (abbreviated as: 2mDBTBPDBq-II), 2-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f [h]quinoxaline (abbreviation: 2mCzBPDBq), 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothiophene-4-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,8-bis[3-(dibenzothiophene-4-yl)phenyl]-benzo[h]quinoxaline (abbreviation: 4,8mDBtP2Bqn), etc.

[0181] As heterocyclic compounds with a pyridine skeleton, for example, 3,5-bis[3-(9H-carbazole-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy) and 1,3,5-tris[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB) can be used.

[0182] As heterocyclic compounds with a triazine skeleton, 2-[3'-(9,9-dimethyl-9H-fluorene-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviated as mFBPTzn) and 2-(biphenyl-4-yl)-4-phenyl-6-(9,9'-spirobis[9H-fluorene]-2-yl)-1,3,5-triazine (abbreviated as BP-SFTzn) can be used, for example. 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn-02), etc.

[0183] [Materials with an anthracene skeleton]

[0184] Organic compounds having an anthracene skeleton can be used in layer 113X. In particular, organic compounds having both an anthracene skeleton and a heterocyclic skeleton can be used appropriately.

[0185] For example, organic compounds having both an anthracene skeleton and a nitrogen-containing five-membered ring skeleton can be used in layer 113X. Furthermore, organic compounds having both a nitrogen-containing five-membered ring skeleton containing two heteroatoms and an anthracene skeleton can be used in layer 113X. Specifically, pyrazole rings, imidazole rings, oxazole rings, thiazole rings, etc., can be appropriately used in this heterocyclic skeleton.

[0186] Furthermore, for example, organic compounds having both an anthracene skeleton and a nitrogen-containing six-membered ring skeleton can be used in layer 113X. Additionally, organic compounds having both a nitrogen-containing six-membered ring skeleton containing two heteroatoms and an anthracene skeleton can be used in layer 113X. Specifically, pyrazine rings, pyridine rings, pyridazine rings, etc., can be suitably used in this heterocyclic skeleton.

[0187] [Examples of hybrid material structures]

[0188] Furthermore, materials that mix multiple substances can be used in layer 113X. Specifically, a mixture of materials containing alkali metals, alkali metal compounds or alkali metal complexes and electron transport materials can be used in layer 113X. Note that the highest occupied molecular orbital (HOMO) energy level of the electron transport material is more preferably -6.0 eV or higher.

[0189] Note that the mixed material can be appropriately used in layer 113X in combination with the structure of layer 104X described in Embodiment 3. For example, a composite material of an electron-receiving material and a hole-transporting material can be used in layer 104X. Specifically, a composite material of an electron-receiving material and a material having a deep HOMO energy level HM1 of -5.7 eV or higher and -5.4 eV or lower can be used in layer 104X. By combining this mixed material with the structure of layer 104X, the reliability of the light-emitting device can be improved.

[0190] Furthermore, it is preferable to combine a structure in which the mixed material is used in layer 113X and the composite material is used in layer 104X, and a hole-transporting material is used in layer 112X. For example, a material having a HOMO level HM2 in the range of -0.2 eV to 0 eV relative to the deeper HOMO level HM1 can be used in layer 112X. This improves the reliability of the light-emitting device. Note that in this specification, the light-emitting device is sometimes referred to as a Recombination-Site Tailoring Injection structure (ReSTI structure).

[0191] Alkali metals, alkali metal compounds, or alkali metal complexes are preferably present in a manner that creates a concentration difference (including the case where the concentration is 0) along the thickness direction of layer 113X.

[0192] For example, metal complexes having an 8-hydroxyquinoline structure can be used. Alternatively, methyl-substituted derivatives of metal complexes having an 8-hydroxyquinoline structure (e.g., 2-methyl-substituted or 5-methyl-substituted derivatives) can also be used.

[0193] As metal complexes having an 8-hydroxyquinoline structure, lithium 8-hydroxyquinoline (Liq) and sodium 8-hydroxyquinoline (Naq) can be used. In particular, among complexes of monovalent metal ions, lithium complexes are preferred, and Liq is more preferred.

[0194] <<Example 1 of the structure of layer 111X>>

[0195] For example, a luminescent material or a combination of a luminescent material and a host material can be used in layer 111X. Furthermore, layer 111X can be referred to as a light-emitting layer. Preferably, layer 111X is disposed in regions where holes and electrons recombine. This allows the energy generated by carrier recombination to be efficiently converted into light and emitted.

[0196] Furthermore, layer 111X is preferably disposed away from the metal used for electrodes, etc. Therefore, quenching caused by the metal used for electrodes, etc., can be suppressed.

[0197] Furthermore, it is preferable to adjust the distance from the reflective electrode to the layer 111X so that the layer 111X is positioned at a suitable location corresponding to the emission wavelength. This allows the amplitude to be mutually reinforced by utilizing the interference phenomenon between the light reflected from the electrode and the light emitted by the layer 111X. Furthermore, light of a predetermined wavelength can be amplified to narrow the spectrum. Additionally, a vivid emission color with higher light intensity can be obtained. In other words, a microcavity structure can be obtained by positioning the layer 111X at a suitable location between the electrodes.

[0198] For example, fluorescent substances, phosphorescent substances, or substances exhibiting thermally activated delayed fluorescence (TADF) (also known as TADF materials) can be used as luminescent materials. Thus, the energy generated by carrier recombination can be emitted from the luminescent material as light (see [reference]). Figure 4 ).

[0199] [Fluorescent substances]

[0200] Fluorescent materials can be used in layer 111X. For example, the following fluorescent materials can be used in layer 111X. Note that the fluorescent materials are not limited to these; various known fluorescent materials can be used in layer 111X.

[0201] Specifically, 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), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluorene-9-yl)phenyl]pyrene-1,6-diamine (abbreviated as: 1,6FLPAPrn), and N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluorene-9-yl)phenyl]pyrene-1,6 3-Diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)-4'-(10-phenyl-9-anthrayl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-anthrayl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazol-3-amine (abbreviation: PC) APA), perylene, 2,5,8,11-tetra(tert-butyl)perylene (abbreviated as TBP), 4-(10-phenyl-9-anthrayl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as PCPAPA), N,N”-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis(N,N',N'-triphenyl-1,4-phenylenediamine) (abbreviated as DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthrayl)phenyl]-9H-carbazole-3-amine (abbreviated as 2PCAPPA), N,N'-(pyrene-1,6-) 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 (abbreviated as 3,10PCA2Nbf(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviated as 3,10FrA2Nbf(IV)-02), etc.

[0202] In particular, fused aromatic diamine compounds, such as pyrene diamine compounds like 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03, are preferred due to their high hole trapping ability and good luminescence efficiency or reliability.

[0203] Alternatively, N-[4-(9,10-diphenyl-2-anthrayl)phenyl]-N,N',N'-triphenyl-1,4-phenylene diamine (abbreviated as: 2DPAPPA), N,N,N',N',N",N",N"',N"'-octaphenyldibenzo[g,p] can be used. -2,7,10,15-Tetraamine (abbreviation: DBC1), Coumarin 30, 9,10-Diphenyl-2-[N-phenyl-N-(9-phenyl-carbazole-3-yl)amino]anthracene (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-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(biphenyl-2-yl)amino]-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-yl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(biphenyl-2-yl)amino]-2,7,10,15-tetraamine (abbreviation: 2DPAPA), N-[9,10-bis(biphenyl-2-yl)-2-phenylenedi ... [-2-anthrayl]-N,N',N'-triphenyl-1,4-phenylene diamine (abbreviation: 2DPABPhA), 9,10-bis(biphenyl-2-yl)-N-[4-(9H-carbazole-9-yl)phenyl]-N-phenylaminoanthracene-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracene-9-amine (abbreviation: DPhAPhA), coumarin 545T, N,N'-diphenylquinacridone (abbreviation: DPQd), rubrene, 5,12-bis(biphenyl-4-yl)-6,11-diphenyltetraphenyl (abbreviation: BPT), etc.

[0204] In addition, 2-(2-{2-[4-(dimethylamino)phenyl]vinyl}-6-methyl-4H-pyran-4-ylidene)malononitrile (abbreviated as: DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinazin-9-yl)vinyl]-4H-pyran-4-ylidene}malononitrile (abbreviated as: DCM2), N,N,N' can be used. N'-Tetra(4-methylphenyl)-tetraphenyl-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetra(4-methylphenyl)acenaphthene[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5-diamine] H-Benzo[ij]quinazine-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]quinazine-9-yl)vinyl]-4H-pyran-4-ylidene}malonium (abbreviation: DCJTB), 2-(2,6-bis) {2-[4-(dimethylamino)phenyl]vinyl}-4H-pyran-4-ylidene)malononitrile (abbreviated as BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinazin-9-yl)vinyl]-4H-pyran-4-ylidene}malononitrile (abbreviated as BisDCJTM), etc.

[0205] [Phosphorescent substances]

[0206] Phosphorescent materials can be used in layer 111X. For example, the following phosphorescent materials can be used in layer 111X. Note that the phosphorescent materials are not limited to these, and various known phosphorescent materials can be used in layer 111X.

[0207] For example, the following materials can be used in layer 111X: organometallic iridium complexes with a 4H-triazole skeleton, organometallic iridium complexes with a 1H-triazole skeleton, organometallic iridium complexes with an imidazole skeleton, organometallic iridium complexes with electron-withdrawing groups and phenylpyridine derivatives as ligands, organometallic iridium complexes with a pyrimidine skeleton, organometallic iridium complexes with a pyrazine skeleton, organometallic iridium complexes with a pyridine skeleton, rare earth metal complexes, platinum complexes, etc.

[0208] [Phosphorescent material (blue)]

[0209] As organometallic iridium complexes with a 4H-triazole skeleton, for example, tri{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN] can be used. 2 Iridium (III) of the phenyl-κC group (abbreviated as [Ir(mpptz-dmp)3]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolium(triazolato))iridium(III) (abbreviated as [Ir(Mptz)3]), tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolium(triazolato)]iridium(III) (abbreviated as [Ir(iPrptz-3b)3]), etc.

[0210] Organometallic iridium complexes with a 1H-triazole skeleton, for example, can be tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviated as [Ir(Mptz1-mp)3]) or tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato))iridium(III) (abbreviated as [Ir(Prptz1-Me)3]).

[0211] As organometallic iridium complexes with an imidazole skeleton, for example, fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazolium]iridium(III) (abbreviated as [Ir(iPrpim)3]) and tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviated as [Ir(dmpimpt-Me)3]) can be used.

[0212] Organometallic iridium complexes, such as those using phenylpyridine derivatives with electron-withdrawing groups as ligands, can be used, for example, bis[2-(4',6'-difluorophenyl)pyridinium-N,C 2’ Iridium(III) tetratetra(1-pyrazole)borate (abbreviated as FIR6), bis[2-(4',6'-difluorophenyl)pyridinium-N,C] 2’ Iridium(III)pyridinecarboxylate (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’ Iridium(III) acetylacetone (abbreviated as FIracac), etc.

[0213] The aforementioned substance is a compound that emits blue phosphorescence and has a peak emission wavelength between 440 nm and 520 nm.

[0214] [Phosphorescent material (green)]

[0215] As organometallic iridium complexes with a pyrimidine skeleton, for example, 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 ... and (acetylacetonate)bis(6-tert-butyl-4-phenylpyrimidine)iridium(III) (abbreviated as: [Ir(mppm)3]) can be used. (r(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)2(acac)]), (acetylacetonate)bis(4,6-diphenylpyrimidine)iridium(III) (abbreviated as: [Ir(dppm)2(acac)]), etc.

[0216] As organometallic iridium complexes with a pyrazine skeleton, for example, (acetylacetonate)bis(3,5-dimethyl-2-phenylpyrazine)iridium(III) (abbreviated as: [Ir(mppr-Me)2(acac)]) and (acetylacetonate)bis(5-isopropyl-3-methyl-2-phenylpyrazine)iridium(III) (abbreviated as: [Ir(mppr-iPr)2(acac)]) can be used.

[0217] As organometallic iridium complexes with a pyridine skeleton, for example, tris(2-phenylpyridinium-N,C) can be used. 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)]), [2-d3-methyl-8-(2-pyridyl-κN)benzofurano[2,3-b]pyridine-κC]bis[2-(5-d3-methyl-2-pyridyl-κN) 2 [2-(2-pyridyl-κN)benzofurano[2,3-b]pyridyl-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviated as [Ir(5mppy-d3)2(mbfpypy-d3)]), [2-d3-methyl-(2-pyridyl-κN)benzofurano[2,3-b]pyridyl-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviated as [Ir(ppy)2(mbfpypy-d3)]), etc.

[0218] Examples of rare earth metal complexes include tri(acetylacetone)(monophenanthrene)terbium(III) (abbreviated as: [Tb(acac)3(Phen)]).

[0219] The aforementioned substances are primarily compounds that emit green phosphorescence, with emission wavelength peaks in the 500 nm to 600 nm range. Furthermore, organometallic iridium complexes with a pyrimidine framework exhibit particularly superior reliability or luminescent efficiency.

[0220] [Phosphorescent substance (red)]

[0221] As organometallic iridium complexes with a pyrimidine skeleton, for example, (diisobutyrylmethane)bis[4,6-bis(3-methylphenyl)pyrimidinium]iridium(III) (abbreviated as: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinium](dineopentamethanyl)iridium(III) (abbreviated as: [Ir(5mdppm)2(dpm)]), bis[4,6-bis(naphthyl-1-yl)pyrimidinium](dineopentamethanyl)iridium(III) (abbreviated as: [Ir(d1npm)2(dpm)]), etc.

[0222] As organometallic iridium complexes with a pyrazine skeleton, for example, (acetylacetonate)bis(2,3,5-triphenylpyrazine)iridium(III) (abbreviated as [Ir(tppr)2(acac)]), bis(2,3,5-triphenylpyrazine)(dineovaleylmethane)iridium(III) (abbreviated as [Ir(tppr)2(dpm)]), and (acetylacetonate)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviated as [Ir(Fdpq)2(acac)]) can be used.

[0223] As organometallic iridium complexes with a pyridine skeleton, for example, tris(1-phenylisoquinoline-N,C) can be used. 2’Iridium(III) (abbreviated as: [Ir(piq)3]), bis(1-phenylisoquinoline-N,C) 2’ Iridium(III) acetylacetone (abbreviated as: [Ir(piq)2(acac)]) etc.

[0224] As rare earth metal complexes, for example, tris(1,3-diphenyl-1,3-propanedione) (monophenanthrene) europium(III) (abbreviated as [Eu(DBM)3(Phen)]) and tris[1-(2-thiophenecarboxyl)-3,3,3-trifluoroacetone] (monophenanthrene) europium(III) (abbreviated as [Eu(TTA)3(Phen)]) can be used.

[0225] As platinum complexes, for example, 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (abbreviated as PtOEP) can be used.

[0226] The aforementioned substances are compounds that emit red phosphorescence and have an emission peak in the 600 nm to 700 nm range. Furthermore, organometallic iridium complexes with a pyrazine framework can also produce red emission, possessing chromaticity suitable for use in display devices.

[0227] [Substances exhibiting thermally activated delayed fluorescence (TADF)]

[0228] TADF material can be used in layer 111X. Furthermore, when using TADF material as the luminescent material, the S1 energy level of the host material is preferably higher than the S1 energy level of the TADF material. Additionally, the T1 energy level of the host material is preferably higher than the T1 energy level of the TADF material.

[0229] For example, the TADF material shown below can be used as a luminescent material. Note that this is not a limitation; various known TADF materials can be used.

[0230] Because the energy difference between the S1 and T1 levels in TADF materials is small, a small amount of thermal energy can be used to convert a triplet excited state into a singlet excited state via an antisystem crossover (upconversion). Therefore, singlet excited states can be generated efficiently from triplet excited states. Furthermore, the triplet excitation energy can be converted into luminescence.

[0231] Exciplexes formed by two substances in an excited state have the function of converting triple excitation energy into single excitation energy due to the extremely small difference between the S1 and T1 energy levels.

[0232] Note that the phosphorescence spectrum observed at low temperatures (e.g., 77K to 10K) can be used as an indicator of the T1 energy level. For TADF materials, it is preferable that the difference between the S1 and T1 energy levels is 0.3 eV or less, more preferably 0.2 eV or less, when the wavelength energy of the extrapolated line obtained by drawing a tangent at the tail of the short-wavelength side of the fluorescence spectrum is taken as the S1 energy level and the wavelength energy of the extrapolated line obtained by drawing a tangent at the tail of the short-wavelength side of the phosphorescence spectrum is taken as the T1 energy level.

[0233] For example, fullerenes and their derivatives, acridines and their derivatives, and eosin derivatives can be used in TADF materials. Furthermore, metalloporphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd) can be used in TADF materials.

[0234] Specifically, the following structural formulas can be used: protoporphyrin-tin fluoride complex (SnF2(ProtoIX)), mesoporphyrin-tin fluoride complex (SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (SnF2(Hemato IX)), tetramethyl coprophyrin-tin fluoride complex (SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complex (SnF2(OEP)), protoporphyrin-tin fluoride complex (SnF2(Etio I)), and octaethylporphyrin-platinum chloride complex (PtCl2OEP).

[0235] [Chemical Formula 1]

[0236]

[0237] In addition, heterocyclic compounds having one or both of π-electron-rich and π-electron-deficient heterocyclic rings can be used in TADF materials.

[0238] Specifically, the following structural formulas can be used: 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazole-11-yl)-1,3,5-triazine (abbreviated as: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviated as: PCCzTzn), 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-phenoxazine-10-yl]phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviated as: PCCzPTzn), and 2-[4-(10H-phenoxazine-10-yl]phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviated as: PCCzPTzn). [4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazine (abbreviated as PXZ-TRZ), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-oxanthracene-9-one (abbreviated as ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridin)phenyl]sulfone (abbreviated as DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridin-9,9'-anthracene]-10'-one (abbreviated as ACRSA), etc.

[0239] [Chemical Formula 2]

[0240]

[0241] Because these heterocyclic compounds possess both π-electron-rich and π-electron-deficient heteroaromatic rings, they exhibit high electron and hole transport capabilities, making them preferred. In particular, among the skeletons possessing π-electron-deficient heteroaromatic rings, pyridine, diazine (pyrimidine, pyrazine, pyridazine), and triazine skeletons are stable and reliable, and are therefore preferred. Especially, benzofuran-pyrimidine, benzothiophene-pyrimidine, benzofuran-pyrazine, and benzothiophene-pyrazine skeletons exhibit high electron acceptability and good reliability, and are therefore preferred.

[0242] Furthermore, among the skeletons having π-electron-rich heteroaromatic rings, acridine, phenoxazine, phenothiazine, furan, thiophene, and pyrrole skeletons are stable and reliable, so having at least one of these skeletons is preferred. Moreover, dibenzofuran skeleton is preferred as the furan skeleton, and dibenzothiophene skeleton is preferred as the thiophene skeleton. As the pyrrole skeleton, indole, carbazole, indolocarbazole, bicarbazole, and 3-(9-phenyl-9H-carbazole-3-yl)-9H-carbazole skeletons are particularly preferred.

[0243] In substances where π-electron-rich and π-electron-deficient heteroaromatic rings are directly bonded, the π-electron-rich heteroaromatic ring exhibits high electron-donating and electron-accepting properties, while the energy difference between the S1 and T1 energy levels decreases, resulting in highly efficient thermally activated delayed fluorescence. Therefore, it is particularly preferred. Furthermore, aromatic rings bonded with electron-withdrawing groups such as cyano groups can be used instead of π-electron-deficient heteroaromatic rings. Additionally, aromatic amine skeletons, phenazine skeletons, etc., can be used as π-electron-rich skeletons.

[0244] In addition, as π-electron-deficient skeletons, the following can be used: xanthracene skeleton, thioxanthenedioxide skeleton, oxadiazole skeleton, triazole skeleton, imidazole skeleton, anthraquinone skeleton, boron-containing skeletons such as phenylborane or boranthrene, aromatic rings or heteroaromatic rings with nitrile or cyanobenzene, carbonyl skeletons such as benzophenone, phosphine oxide skeleton, sulfone skeleton, etc.

[0245] Thus, at least one of the π-electron-deficient and π-electron-rich heteroaryl rings can be replaced by a π-electron-deficient framework and a π-electron-rich framework.

[0246] <<Example 2 of the structure of layer 111X>>

[0247] Carrier transport materials can be used as host materials. For example, hole transport materials, electron transport materials, substances exhibiting thermally activated delayed fluorescence (TADF), materials with an anthracene framework, and mixed materials can be used as host materials. Note that materials with a band gap larger than that of the luminescent material in layer 111X are preferred as host materials. Therefore, energy transfer from excitons to the host material generated in layer 111X can be suppressed.

[0248] Hole-transporting materials

[0249] The hole mobility can be 1×10 -6 cm 2 Materials with a density of / Vs or higher can be appropriately used as hole-transporting materials. For example, hole-transporting materials suitable for layer 112X can be used for layer 111X.

[0250] Electron transport materials

[0251] Metal complexes or organic compounds with π-electron-deficient heteroaromatic ring skeletons can be used in electron transport materials. For example, electron transport materials that can be used in layer 113X can be used in layer 111X.

[0252] [Materials with an anthracene skeleton]

[0253] Organic compounds with an anthracene framework can be used as host materials. In particular, they are well-suited for use as fluorescent materials. This allows for the development of light-emitting devices with both high luminous efficiency and durability.

[0254] As anthracene-based organic compounds, those with a diphenylanthracene skeleton, especially those with a 9,10-diphenylanthracene skeleton, are chemically stable and therefore preferred. Furthermore, when the host material has a carbazole skeleton, hole injection and transport are improved, making it preferred. In particular, when the host material has a dibenzo-carbazole skeleton, its HOMO level is approximately 0.1 eV shallower than that of a host material with a carbazole skeleton, which not only facilitates hole injection but also improves hole transport and heat resistance, making it preferred. Note that from the perspective of hole injection and transport, a benzo[a]fluorene skeleton or a dibenzo[a]fluorene skeleton can also be used instead of a carbazole skeleton.

[0255] Therefore, substances having a 9,10-diphenylanthracene skeleton and a carbazole skeleton, substances having a 9,10-diphenylanthracene skeleton and a benzo[carbazole] skeleton, and substances having a 9,10-diphenylanthracene skeleton and a dibenzo[carbazole] skeleton are preferably used as the main material.

[0256] For example, 6-[3-(9,10-diphenyl-2-anthracene)phenyl]benzo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10-[4'-(9-phenyl-9H-fluorene-9-yl)biphenyl-4-yl]anthracene (abbreviation: FLPPA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth), 9-[4-(9-phenylcarbazole] The following are listed: 3-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviated as PCzPA), 7-[4-(10-phenyl-9-anthracenyl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviated as cgDBCzPA), 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPN), etc.

[0257] In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA exhibit very good properties.

[0258] Materials exhibiting thermally activated delayed fluorescence (TADF)

[0259] TADF materials can be used as the host material. When using TADF materials as the host material, the triplet excitation energy generated in the TADF material can be converted into a singlet excitation energy through anti-intersystem crossing. Furthermore, the excitation energy can be transferred to the luminescent material. In other words, the TADF material is used as an energy donor, and the luminescent material is used as an energy acceptor. This improves the luminous efficiency of the light-emitting device.

[0260] This is highly effective when the luminescent material is a fluorescent material. Furthermore, to obtain high luminescent efficiency, the S1 energy level of the TADF material is preferably higher than the S1 energy level of the fluorescent material. Additionally, the T1 energy level of the TADF material is preferably higher than the S1 energy level of the fluorescent material. Therefore, the T1 energy level of the TADF material is preferably higher than the T1 energy level of the fluorescent material.

[0261] Furthermore, it is preferable to use a TADF material that emits light at a wavelength that overlaps with the absorption band on the lowest energy side of the fluorescent material. This allows for efficient transfer of excitation energy from the TADF material to the fluorescent material, resulting in highly efficient luminescence, and is therefore preferred.

[0262] To efficiently generate a singlet excitation energy from a triplet excitation energy via antisystem crossing, it is preferable to generate carrier recombination within the TADF material. Furthermore, it is preferable that the triplet excitation energy generated in the TADF material does not transfer to the triplet excitation energy of the fluorescent material. For this purpose, the fluorescent material preferably has a protecting group surrounding its luminescent component (the backbone that causes luminescence). This protecting group is preferably a substituent without π bonds, preferably a saturated hydrocarbon; specifically, examples include alkyl groups with 3 or more but less than 10 carbon atoms, substituted or unsubstituted cycloalkyl groups with 3 or more but less than 10 carbon atoms, and trialkylsilyl groups with 3 or more but less than 10 carbon atoms; more preferably, a group with multiple protecting groups. Substituents without π bonds have almost no function in transporting carriers, so they have little effect on carrier transport or carrier recombination, allowing the TADF material and the luminescent component of the fluorescent material to be kept apart.

[0263] Here, the luminescent body refers to the atomic group (backbone) that causes luminescence in a fluorescent material. The luminescent body is preferably a backbone with π bonds, more preferably an aromatic ring, and even more preferably a fused aromatic ring or a fused heteroaromatic ring.

[0264] Examples of the aforementioned luminescent materials include phenanthrene skeletons, stilbene skeletons, acridinone skeletons, phenoxazine skeletons, phenothiazine skeletons, naphthalene skeletons, anthracene skeletons, and fluorene skeletons. The skeleton includes triphenylene skeleton, tetraphenylene skeleton, pyrene skeleton, perylene skeleton, coumarin skeleton, quinacridone skeleton, naphthobisbenzofuran skeleton, etc. In particular, those possessing naphthalene skeleton, anthracene skeleton, fluorene skeleton, etc. Fluorescent materials with skeletons such as triphenylene skeleton, tetraphenylene skeleton, pyrene skeleton, perylene skeleton, coumarin skeleton, quinacridone skeleton, and naphthobisbenzofuran skeleton have high fluorescence quantum yields and are therefore preferred.

[0265] For example, TADF materials, which can be used in luminescent materials, can be used as the host material.

[0266] [Example 1 of a hybrid material structure]

[0267] Furthermore, materials that mix multiple substances can be used as the host material. For example, electron transport materials and hole transport materials can be used in the hybrid material. In the hybrid material, the weight ratio of hole transport material relative to electron transport material can be (hole transport material / electron transport material) = (1 / 19) or more and (19 / 1) or less. This allows for easy adjustment of the carrier transport properties of layer 111X. Furthermore, the control of the composite region can be made simpler.

[0268] [Example 2 of a hybrid material structure]

[0269] Materials containing phosphorescent substances can be used as the host material. When phosphorescent substances are used as luminescent materials or fluorescent materials, they can be used as energy donors to supply excitation energy to the fluorescent materials.

[0270] [Example 3 of a hybrid material structure]

[0271] A mixed material containing materials that form exciplexes can be used as the host material. For example, a material whose emission spectrum overlaps with the wavelength of the absorption band on the lowest energy side of the luminescent material can be used as the host material. Therefore, energy transfer can be facilitated, thereby improving luminescence efficiency. Furthermore, the driving voltage can be suppressed. By employing such a structure, ExTET (Exciplex-Triplet Energy Transfer) luminescence utilizing energy transfer from the exciplex to the luminescent material (phosphorescent material) can be efficiently obtained.

[0272] Phosphorescent materials can be used in at least one of the materials forming excitocomplexes. This allows for the utilization of antisystem crossing. Alternatively, triple excitation energies can be efficiently converted into single excitation energies.

[0273] As a combination of materials for forming excitocomplexes, the HOMO energy level of the hole-transporting material is preferably higher than the HOMO energy level of the electron-transporting material. Alternatively, the lowest unoccupied molecular orbital (LUMO) energy level of the hole-transporting material is preferably higher than the LUMO energy level of the electron-transporting material. This allows for efficient formation of excitocomplexes. Furthermore, the LUMO and HOMO energy levels of the material can be determined from electrochemical properties (reduction potential and oxidation potential). Specifically, the reduction potential and oxidation potential can be measured using cyclic voltammetry (CV).

[0274] Note that the formation of excitocomplexes can be confirmed, for example, by comparing the emission spectra of hole-transporting materials, electron-transporting materials, and the emission spectra of a hybrid film formed by mixing these materials. When the emission spectrum of the hybrid film is observed to shift towards a longer wavelength (or to have a new peak on the longer wavelength side) compared to the emission spectra of each material, it indicates the formation of excitocomplexes. Alternatively, by comparing the transient photoluminescence (PL) of hole-transporting materials, the transient PL of electron-transporting materials, and the transient PL of a hybrid film formed by mixing these materials, when a difference in transient response is observed, such as the mixed film having a longer lifetime component or a higher proportion of delayed components compared to the transient PL lifetimes of each material, it indicates the formation of excitocomplexes. Furthermore, the aforementioned transient PL can be referred to as transient electroluminescence (EL). In other words, by comparing the transient EL of hole-transporting materials, the transient EL of electron-transporting materials, and the transient EL of a hybrid film of these materials, and observing the differences in transient responses, the formation of excitocomplexes can be confirmed.

[0275] This embodiment can be appropriately combined with other embodiments shown in this specification.

[0276] (Implementation Method 3)

[0277] In this embodiment, refer to Figure 4 The structure of the light source LSX of a light-emitting device that can be used in one aspect of the present invention is described.

[0278] The structure of the light source LSX described in this embodiment can be used in a display device according to one aspect of the present invention. Specifically, the symbol "X" for the structure of the light source LSX can be replaced with "A" to describe the light source LSA. Similarly, "X" can be replaced with "B" or "C" to apply the structure of the light source LSX to the light source LSB or light source LSC.

[0279] <Structural Example of a Light Source LSX>

[0280] The light source LSX described in this embodiment includes electrode 551X, electrode 552X, unit 103X, and layer 104X (see reference). Figure 4 ).

[0281] Electrode 552X overlaps with electrode 551X, and unit 103X is located between electrode 551X and electrode 552X. Furthermore, layer 104X is located between electrode 551X and unit 103X. Note that, for example, the structure described in embodiment 2 can be used for unit 103X.

[0282] <Structural Example of Electrode 551X>

[0283] For example, conductive materials can be used in electrode 551X. Specifically, a single layer or stack of films containing metals, alloys, or conductive compounds can be used in electrode 551X.

[0284] For example, a film that efficiently reflects light can be used in electrode 551X. Specifically, an alloy containing silver and copper, an alloy containing silver and palladium, or a metal film such as aluminum can be used in electrode 551X.

[0285] Furthermore, for example, a metal film that allows a portion of the light to pass through and the rest to be reflected can be used for the electrode 551X. This allows the light source LSX to have a microcavity structure. Furthermore, light of a specified wavelength can be extracted more efficiently compared to other light sources. Furthermore, light with a full width at half maximum (FWHM) of the spectrum can be extracted. Furthermore, light with vivid colors can be extracted.

[0286] Furthermore, for example, a film that is transparent to visible light can be used for electrode 551X. Specifically, a single layer or stack of a metal film, alloy film, or conductive oxide film that is thin enough to transmit light can be used for electrode 551X.

[0287] For example, conductive oxides containing indium can be used. Specifically, indium oxide, indium tin oxide (ITO), indium tin oxide containing silicon or silicon oxide (ITSO), indium zinc oxide, and indium oxide containing tungsten oxide and zinc oxide (IWZO) can be used.

[0288] In addition, conductive oxides containing zinc can be used, for example. Specifically, zinc oxide, zinc oxide with gallium added, zinc oxide with aluminum added, etc., can be used.

[0289] In addition, materials such as gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), or nitrides of metallic materials (e.g., titanium nitride) can be used. Furthermore, graphene can be used.

[0290] In particular, when the electrode 551X is used as the anode of the light source LSX, it is preferable to use a material with a work function of 4.0 eV or higher.

[0291] <<Example 1 of a 104X Layer Structure>>

[0292] For example, a hole-injecting material can be used for layer 104X. Furthermore, layer 104X can be referred to as a hole-injecting layer.

[0293] For example, the hole mobility can be 1×10 when the square root of the electric field strength V / cm is 600. -3 cm 2 Materials with a value of / Vs or less can be used for layer 104X. Additionally, materials with a value of 1×10 can be used. 4 Ω·cm or more and 1×10 7 A film with a resistivity of less than Ω·cm is used for layer 104X. Furthermore, layer 104X preferably has a resistivity of 5 × 10⁻⁶ Ω·cm. 4 Ω·cm or more and 1×10 7 Resistivity below Ω·cm, more preferably 1×10 5 Ω·cm or more and 1×10 7 Resistivity below Ω·cm.

[0294] <<Example 2 of a 104X Layer Structure>>

[0295] Specifically, electron-accepting materials can be used in layer 104X. Alternatively, composite materials containing multiple substances can be used in layer 104X.

[0296] Specifically, 1×10⁻⁶ can be observed in the membrane state using electron spin resonance. 18 spins / cm 3 The material with the above spin density is used in layer 104X. Therefore, for example, holes can be easily injected from electrode 551X. Furthermore, the driving voltage of the light source LSX can be reduced.

[0297] Electron-receiving substances

[0298] Organic and inorganic compounds can be used as electron-accepting substances.

[0299] For example, compounds with electron-withdrawing groups (halogen or cyano groups) can be used as electron-accepting materials. Furthermore, electron-accepting organic compounds can be easily deposited using vapor deposition. Therefore, the productivity of light source LSXs can be improved.

[0300] Specifically, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinone dimethyl ether (abbreviated as F4-TCNQ), chloroquinone, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviated as HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinone dimethyl ether (abbreviated as F6-TCNNQ), and 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyrene-2-ylidene)malonitrile, etc., can be used.

[0301] In particular, compounds with electron-withdrawing groups such as HAT-CN bonded to fused aromatic rings with multiple heteroatoms are thermally stable and are therefore preferred.

[0302] Furthermore, [3] axylene derivatives, which include electron-withdrawing groups (especially halogens such as fluorine or cyano groups), are preferred because they have very high electron acceptability.

[0303] Specifically, α,α',α”-1,2,3-cyclopropanetrimethylenetri[4-cyano-2,3,5,6-tetrafluorophenylacetonitrile], α,α',α”-1,2,3-cyclopropanetrimethylenetri[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)phenylacetonitrile], and α,α',α”-1,2,3-cyclopropanetrimethylenetri[2,3,4,5,6-pentafluorophenylacetonitrile] can be used.

[0304] In addition, transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide can be used as electron-accepting materials.

[0305] In addition, phthalocyanine compounds or complexes such as phthalocyanine (abbreviated as: H2Pc), copper(II) phthalocyanine (abbreviated as: CuPc) and other compounds with aromatic amine skeletons such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as: DPAB), N,N'-bis[4-bis(3-methylphenyl)aminophenyl]-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviated as: DNTPD) and other compounds can be used.

[0306] In addition, polymers such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (abbreviated as: PEDOT / PSS) can be used.

[0307] [Structural Example 1 of Composite Materials]

[0308] Furthermore, for example, a composite material containing both electron-receiving and hole-transporting materials can be used for layer 104X. Thus, regardless of the work function, materials for electrode 551X can be selected from a wide range of materials.

[0309] For example, compounds with aromatic amine skeletons, carbazole derivatives, aromatic hydrocarbons, vinyl aromatic hydrocarbons, and polymers (oligomers, dendritic polymers, polymers, etc.) can be used as hole transport materials in composite materials. Furthermore, materials with a hole mobility of 1×10⁻⁶ can be used. -6 cm 2 Materials with a density of / Vs or higher are suitable for use as hole-transporting materials in composite materials. For example, hole-transporting materials suitable for layer 112X can be used as composite materials.

[0310] Furthermore, materials with deep HOMO energy levels can be suitable for use as hole-transporting materials in composite materials. Specifically, the HOMO energy level is preferably above -5.7 eV and below -5.4 eV. This allows for easy hole injection into cell 103X. Furthermore, it allows for easy hole injection into layer 112X. Additionally, it improves the reliability of the light source LSX.

[0311] As compounds with an aromatic amine skeleton, 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).

[0312] As carbazole derivatives, for example, 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), 3-[N-(1-naphthyl)-N-(9-phenylcarbazole-3-yl)amino]-9-phenylcarbazole (abbreviated as PCzPCN1), 4,4'-bis(N-carbazole)biphenyl (abbreviated as CBP), 1,3,5-tris[4-(N-carbazole)phenyl]benzene (abbreviated as TCPB), 9-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole (abbreviated as CzPA), 1,4-bis[4-(N-carbazole)phenyl]-2,3,5,6-tetraphenylbenzene, etc.

[0313] As aromatic hydrocarbons, for example, 2-tert-butyl-9,10-bis(2-naphthyl)anthracene (abbreviated as t-BuDNA), 2-tert-butyl-9,10-bis(1-naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviated as DPPA), 2-tert-butyl-9,10-bis(4-phenylphenyl)anthracene (abbreviated as t-BuDBA), 9,10-bis(2-naphthyl)anthracene (abbreviated as DNA), 9,10-diphenylanthracene (abbreviated as DPANth), 2-tert-butylanthracene (abbreviated as t-BuAnth), 9,10-bis(4-methyl-1-naphthyl)anthracene (abbreviated as DMNA), 2-tert-butylanthracene, etc., can be used. 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-butyl)perylene, pentaphenyl, halophenyl, etc.

[0314] As aromatic hydrocarbons containing vinyl groups, for example, 4,4'-bis(2,2-diphenylvinyl)biphenyl (abbreviated as DPVBi) and 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviated as DPVPA) can be used.

[0315] As high molecular weight compounds, for example, poly(N-vinylcarbazole) (abbreviated as PVK), poly(4-vinyltriphenylamine) (abbreviated as PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviated as PTPDMA), poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviated as Poly-TPD), etc.

[0316] Furthermore, substances having any one of the following skeletons—carbazole, dibenzofuran, dibenzothiophene, and anthracene—can be suitable for use as hole-transporting materials in composite materials. Additionally, substances containing aromatic amines having substituents including a dibenzofuran ring or a dibenzothiophene ring, aromatic monoamines including a naphthyl ring, or aromatic monoamines with a 9-fluorene group bonded to the nitrogen of the amine via an arylene group can be used. Note that using substances including N,N-bis(4-biphenyl)amino groups can improve the reliability of the light source LSX.

[0317] For example, N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviated as: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviated as: BBABnf), 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4”-phenyltriphenylamine (abbreviated as: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviated as: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviated as: BBA) Bnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl-4-benzidine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4”-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4”-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4”-(6;1'-binaphthyl-2-yl)triphenylamine Phenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4”-(7;1'-binathyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4”-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4”-(6;2'-binathyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4”-(7;2'-binathyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4”-(4;2'-binathyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4 '-Diphenyl-4'-(5;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenyl)-4'-(2-naphthyl)-4"-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenyl)-4'-[4-(2-naphthyl)phenyl]-4"-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenyl)-4'-[4-(2-naphthyl)phenyl]-4"-phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-Diphenyl-4”-[4'-(carbazole-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazole-9-yl)phenyl]tri(1,1'-biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazole-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4”-phenyltriphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirodi[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N-bis(biphenyl-4-yl)-9,9' -spirodi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(biphenyl-4-yl)-9,9'-spirodi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirodi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluorene-2-yl)-dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-( 9-Phenylen-9-yl)triphenylamine (abbreviation: BPAFLP), 4-Phenylen-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-Phenylen-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-Phenylen-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-Diphenyl-4”-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCCBI1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)- 4”-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCCNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirodi[9H-fluorene]-2-amine (abbreviated as: PCBASF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviated as: PCBiF), N,N-bis(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirodi-9H-fluorene-4-amine, N,N-bis(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirodi-9H-fluorene-3-amine, N,N-bis(9,9-Dimethyl-9H-fluorene-2-yl)-9,9'-spirodi-9H-fluorene-2-amine, N,N-bis(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirodi-9H-fluorene-1-amine, etc.

[0318] [Structural Example 2 of Composite Materials]

[0319] For example, composite materials containing electron-receiving materials, hole-transporting materials, and fluorides of alkali metals or alkaline earth metals can be used as hole-injecting materials. In particular, composite materials with an atomic ratio of fluorine atoms of 20% or more are suitable for use. Therefore, the refractive index of layer 104X can be reduced. Furthermore, a low-refractive-index layer can be formed inside the light source LSX. In addition, the external quantum efficiency of the light source LSX can be improved.

[0320] Note that this embodiment can be appropriately combined with other embodiments shown in this specification.

[0321] (Implementation Method 4)

[0322] In this embodiment, refer to Figure 4 The structure of the light source LSX of a light-emitting device that can be used in one aspect of the present invention is described.

[0323] The structure of the light source LSX described in this embodiment can be used in a display device according to one aspect of the present invention. Specifically, the symbol "X" for the structure of the light source LSX can be replaced with "A" to describe the light source LSA. Similarly, "X" can be replaced with "B" or "C" to apply the structure of the light source LSX to the light source LSB or light source LSC.

[0324] <Structural Example of a Light Source LSX>

[0325] The light source LSX described in this embodiment includes an electrode 551X, an electrode 552X, a unit 103X, and a layer 105X. Electrode 552X includes a region overlapping with electrode 551X, and unit 103X includes a region sandwiched between electrode 551X and electrode 552X. Furthermore, layer 105X includes a region sandwiched between unit 103X and electrode 552X. Note that, for example, the structure described in Embodiment 2 can be used for unit 103X.

[0326] <Structural Example of Electrode 552X>

[0327] For example, conductive materials can be used in electrode 552X. Specifically, a single layer or stack of materials comprising metals, alloys, or conductive compounds can be used in electrode 552X.

[0328] For example, the material that can be used for electrode 551X as described in Embodiment 3 can be used for electrode 552X.

[0329] In particular, when electrode 552X is used as the anode of the light source LSX, it is preferable to use a material with a lower work function than electrode 551X for electrode 552X. Specifically, a material with a work function of 3.8 eV or less can be used.

[0330] For example, elements belonging to Group 1 of the periodic table, elements belonging to Group 2 of the periodic table, rare earth metals, and alloys containing them can be used in electrode 552X.

[0331] Specifically, lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), strontium (Sr), europium (Eu), ytterbium (Yb), and alloys containing them (such as magnesium-silver alloys or aluminum-lithium alloys) can be used in electrode 552X.

[0332] <<Example of a 105X Layer Structure>>

[0333] For example, an electron-injectable material can be used for layer 105X. Furthermore, layer 105X can be referred to as an electron-injected layer.

[0334] Specifically, an electron-donating material can be used for layer 105X. Alternatively, a composite material of an electron-donating material and an electron-transporting material can be used for layer 105X. Alternatively, an electron compound can be used for layer 105X. Thus, for example, electrons can be easily injected from electrode 552X. Alternatively, materials for electrode 552X can be selected from a wide range of materials regardless of the work function. Specifically, aluminum (Al), silver (Ag), indium tin oxide (ITO), and indium tin oxide containing silicon or silicon oxide can be used for electrode 552X. Furthermore, the driving voltage of the light source LSX can be reduced.

[0335] [Substances with electron-donating properties]

[0336] For example, alkali metals, alkaline earth metals, rare earth metals, or their compounds (oxides, halides, carbonates, etc.) can be used as electron-donating substances. Furthermore, organic compounds such as tetrathianaphthacene (TTN), nickel dicene, and decamethylnickel dicene can be used as electron-donating substances.

[0337] As alkali metal compounds (including oxides, halides, and carbonates), lithium oxide, lithium fluoride (LiF), cesium fluoride (CsF), lithium carbonate, cesium carbonate, and 8-hydroxyquinoline-lithium (Liq) can be used.

[0338] Calcium fluoride (CaF2) and other compounds can be used as alkaline earth metal compounds (including oxides, halides, and carbonates).

[0339] [Structural Example 1 of Composite Materials]

[0340] Furthermore, materials that combine multiple substances can be used as electron-injecting materials. For example, substances with electron-supplying and electron-transporting properties can be used in composite materials.

[0341] Electron transport materials

[0342] For example, the following material can be applied to electron transport materials: Under the condition that the square root of the electric field strength [V / cm] is 600, the electron mobility is 1×10⁻⁶. -7 cm 2 / Vs or more and 5×10 -5 cm 2 / Vs or less. This allows for control over the amount of electrons injected into the emissive layer. Furthermore, it prevents the emissive layer from becoming overloaded with electrons.

[0343] Metal complexes or organic compounds with π-electron-deficient heteroaromatic ring skeletons can be used in electron transport materials. For example, electron transport materials that can be used in layer 113X can be used in layer 105X.

[0344] [Structural Example 2 of Composite Materials]

[0345] Furthermore, fluorides of alkali metals in a microcrystalline state and electron transport materials can be used in composite materials. Additionally, fluorides of alkaline earth metals in a microcrystalline state and electron transport materials can be used in composite materials. In particular, composite materials containing fluorides of alkali metals or alkaline earth metals of 50 wt% or more are suitable. Furthermore, composite materials containing organic compounds with a bipyridine framework are suitable. Therefore, the refractive index of layer 105X can be reduced. Furthermore, the external quantum efficiency of the LSX light source can be improved.

[0346] [Structural Example 3 of Composite Materials]

[0347] For example, a composite material comprising a first organic compound having non-shared electron pairs and a first metal can be used for layer 105X. Furthermore, the sum of the number of electrons in the first organic compound and the first metal is preferably an odd number. Additionally, the molar ratio of the first metal to 1 mole of the first organic compound is preferably 0.1 or more and 10 or less, more preferably 0.2 or more and 2 or less, and even more preferably 0.2 or more and 0.8 or less.

[0348] Thus, the first organic compound with non-shared electron pairs can interact with the first metal to form a single-occupied molecular orbital (SOMO). Furthermore, by injecting electrons from electrode 552X into layer 105X, the potential barrier between them can be reduced.

[0349] Furthermore, a composite material can be used in layer 105X, wherein the spin density, as measured by electron spin resonance (ESR), is preferably 1 × 10⁻⁶. 16 spins / cm 3 The above is preferred, with 5×10 being more ideal. 16 spins / cm 3 The above is further preferred to be 1×10 17 spins / cm 3 above.

[0350] [Organic compounds with non-shared electron pairs]

[0351] For example, electron-transporting materials can be used in organic compounds with non-shared electron pairs. For instance, compounds with π-electron-deficient heteroaromatic rings can be used. Specifically, compounds having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), and a triazine ring can be used. This allows for a reduction in the driving voltage of the light source LSX.

[0352] Furthermore, the LUMO energy level of organic compounds with non-shared electron pairs is preferably above -3.6 eV and below -2.3 eV. Generally, cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, and inverse photoelectron spectroscopy can be used to estimate the HOMO and LUMO energy levels of organic compounds.

[0353] For example, as organic compounds with non-shared electron pairs, 4,7-diphenyl-1,10-phenanthroline (abbreviated as BPhen), 2,9-di(naphthyl-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA), 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviated as TmPPPyTz), and 2,2'-(1,3-phenylene)bis[(9-phenyl-1,10-phenanthroline] (abbreviated as mPPhen2P) can be used. Furthermore, compared to BPhen, NBPhen has a higher glass transition temperature (Tg), thus exhibiting higher heat resistance.

[0354] Furthermore, copper phthalocyanine can be used, for example, as an organic compound with non-shared electron pairs. Copper phthalocyanine has an odd number of electrons.

[0355] [First Metal]

[0356] For example, when the number of electrons in the first organic compound having non-shared electron pairs is even, a composite material of the first metal and the first organic compound belonging to an odd group in the periodic table can be used for layer 105X.

[0357] For example, manganese (Mn) from Group 7, cobalt (Co) from Group 9, copper (Cu), silver (Ag), and gold (Au) from Group 11, and aluminum (Al) and indium (In) from Group 13 all belong to odd-numbered groups in the periodic table. Furthermore, Group 11 elements have lower melting points than Group 7 or Group 9 elements, making them suitable for vacuum evaporation. Ag, in particular, has a low melting point, making it a preferred choice. Moreover, by using a metal with low reactivity with water or oxygen as the first metal, the moisture resistance of the light source LSX can be improved.

[0358] By using Ag in electrode 552X and layer 105X, the adhesion between layer 105X and electrode 552X can be improved.

[0359] Furthermore, when the number of electrons in the first organic compound having non-shared electron pairs is odd, a composite material of the first metal and the first organic compound belonging to an even group in the periodic table can be used for layer 105X. For example, iron (Fe), a Group 8 metal, belongs to an even group in the periodic table.

[0360] [Electronic Compounds]

[0361] For example, a mixture of calcium and aluminum oxides with high concentrations of added electrons can be used in electron-injecting materials.

[0362] Note that this embodiment can be appropriately combined with other embodiments shown in this specification.

[0363] (Implementation Method 5)

[0364] In this embodiment, refer to Figure 5A The structure of the light source LSX of a light-emitting device that can be used in one aspect of the present invention is described.

[0365] Figure 5A This is a cross-sectional view illustrating the structure of the light source LSX of a display device that can be used in one aspect of the present invention.

[0366] The structure of the light source LSX described in this embodiment can be used in a display device according to one aspect of the present invention. Specifically, the symbol "X" for the structure of the light source LSX can be replaced with "A" to describe the light source LSA. Similarly, "X" can be replaced with "B" or "C" to apply the structure of the light source LSX to the light source LSB or light source LSC.

[0367] <Structural Example of a Light Source LSX>

[0368] Furthermore, the light source LSX described in this embodiment includes electrode 551X, electrode 552X, unit 103X, and intermediate layer 106X (see reference). Figure 5A ).

[0369] Electrode 552X includes a region overlapping with electrode 551X, and unit 103X includes a region sandwiched between electrode 551X and electrode 552X. Intermediate layer 106X includes a region sandwiched between electrode 552X and unit 103X.

[0370] <<Example 1 of the 106X intermediate layer structure>>

[0371] The intermediate layer 106X has the function of supplying electrons to the anode side and holes to the cathode side by applying a voltage. In addition, the intermediate layer 106X can be referred to as the charge generation layer.

[0372] For example, the hole-injecting material described in Embodiment 3 that can be used for layer 104X can be used for intermediate layer 106X. Specifically, an electron-receiving material or a composite material can be used for intermediate layer 106X.

[0373] For example, a laminated membrane comprising a membrane containing the composite material and a membrane containing a hole transport material can be used as the intermediate layer 106X. Note that the membrane containing the hole transport material is sandwiched between the membrane containing the composite material and the cathode.

[0374] <<Example 2 of the 106X intermediate layer structure>>

[0375] The laminated film of layers 106X1 and 106X2 can be used as the intermediate layer 106X. Layer 106X1 includes a region sandwiched between cell 103X and electrode 552X, and layer 106X2 includes a region sandwiched between cell 103X and layer 106X1.

[0376] <<Example of a 106x1 layer structure>>

[0377] For example, a hole-injecting material that can be used in layer 104X as described in embodiment 3 can be used in layer 106X1. Specifically, an electron-receiving material or a composite material can be used in layer 106X1. Furthermore, a material with a 1×10⁻⁶ particle size distribution can be used.4 Ω·cm or more and 1×10 7 A film with a resistivity of less than Ω·cm is used for layer 106X1. Layer 106X1 preferably has a resistivity of 5×10⁻⁶ Ω·cm. 4 Ω·cm or more and 1×10 7 Ω · A resistivity of less than cm, more preferably 1×10⁻⁶ cm, is preferred. 5 Ω·cm or more and 1×10 7 Resistivity below Ω·cm.

[0378] <<Example of a 106x2 layer structure>>

[0379] For example, the material that can be used for layer 105X as described in embodiment 4 can be used for layer 106X2.

[0380] <<Example 3 of the 106X intermediate layer structure>>

[0381] A laminated film consisting of layers 106X1, 106X2, and an intermediate layer 106X3 can be used for the intermediate layer 106X. The intermediate layer 106X3 includes a region sandwiched between layers 106X1 and 106X2.

[0382] <<Example of a 106x3 layer structure>>

[0383] For example, an electron transport material can be used for layer 106X3. Furthermore, layer 106X3 can be referred to as an electron relay layer. By using layer 106X3, the layer contacting the anode side of layer 106X3 can be moved away from the layer contacting the cathode side of layer 106X3. Furthermore, the interaction between the layer contacting the anode side of layer 106X3 and the layer contacting the cathode side of layer 106X3 can be reduced. Therefore, electrons can be smoothly supplied to the layer contacting the anode side of layer 106X3.

[0384] The following substances are suitable for use in layer 106X3: substances whose LUMO level is located between the LUMO level of the electron-accepting substance in layer 106X1 and the LUMO level of the substance in layer 106X2.

[0385] For example, materials with LUMO energy levels in the range of -5.0 eV and above, preferably -5.0 eV and below -3.0 eV, can be used for layer 106X3.

[0386] Specifically, phthalocyanine materials can be used for layer 106X3. For example, phthalocyanine (abbreviated as H2Pc), copper(II) phthalocyanine (abbreviated as CuPc), zinc phthalocyanine (abbreviated as ZnPc), or metal complexes with metal-oxygen bonds and aromatic ligands can be used for layer 106X3.

[0387] This embodiment can be appropriately combined with other embodiments shown in this specification.

[0388] (Implementation Method 6)

[0389] In this embodiment, refer to Figure 5B and Figure 6 The structure of the light source LSX of a light-emitting device that can be used in one aspect of the present invention is described.

[0390] Figure 5B This indicates that it can be used to have with Figure 5A The diagram shows a cross-sectional view of the structure of the light source LSX of a display device according to one embodiment of the present invention, which has different structures.

[0391] Figure 6 This indicates that it can be used to have with Figure 5B The diagram shows a cross-sectional view of the structure of the light source LSX of a display device according to one embodiment of the present invention, which has different structures.

[0392] The structure of the light source LSX described in this embodiment can be used in a display device according to one aspect of the present invention. Specifically, the symbol "X" for the structure of the light source LSX can be replaced with "A" to describe the light source LSA. Similarly, "X" can be replaced with "B" or "C" to apply the structure of the light source LSX to the light source LSB or light source LSC.

[0393] <Example 1 of the structure of a light source LSX>

[0394] The light source LSX described in this embodiment includes electrode 551X, electrode 552X, unit 103X, intermediate layer 106X, and unit 103X2 (see reference). Figure 5B ).

[0395] Unit 103X is located between electrode 552X and electrode 551X, and intermediate layer 106X is located between electrode 552X and unit 103X.

[0396] Unit 103X2 is located between electrode 552X and intermediate layer 106X. Note that unit 103X2 has the function of emitting light LL2.

[0397] In other words, the light source LSX comprises multiple units stacked between electrodes 551X and 552X. Furthermore, the number of stacked units is not limited to two, but can be three or more. Sometimes, the structure comprising multiple stacked units located between electrodes 551X and 552X and an intermediate layer 106X located between the multiple units is referred to as a stacked light-emitting device or a series-type light-emitting device.

[0398] Therefore, high brightness emission can be achieved while maintaining a low current density. Furthermore, reliability can be improved. Additionally, the driving voltage can be reduced when comparing at the same brightness. Furthermore, power consumption can be suppressed.

[0399] <<Structure Example 1 of Unit 103X2>>

[0400] Unit 103X2 has a single-layer structure or a stacked structure. For example, unit 103X2 includes layers 111X2, 112X2, and 113X2. Note that unit 103X2 has the function of emitting light LL2.

[0401] Layer 111X2 is sandwiched between layer 112X2 and layer 113X2, layer 113X2 is sandwiched between electrode 552X and layer 111X2, and layer 112X2 is sandwiched between layer 111X2 and intermediate layer 106X.

[0402] Furthermore, the structure applicable to element 103X can be used for element 103X2. Specifically, the symbol "X" for the structure used in element 103X can be replaced with "X2" and applied to the description of element 103X2. For example, the same structure as element 103X can be used for element 103X2.

[0403] <<Structure Example 2 of Unit 103X2>>

[0404] A structure different from that of unit 103X can be used for unit 103X2. For example, a structure that emits light with a hue different from that of unit 103X can be used for unit 103X2.

[0405] Specifically, units 103X that emit red and green light and units 103X2 that emit blue light can be stacked together. This provides a light source that emits light of a desired color. For example, a light source that emits white light can be provided.

[0406] <<Structure Example of 106X Intermediate Layer>>

[0407] The intermediate layer 106X has the function of supplying electrons to one of the cells 103X and 103X2 and supplying holes to the other. For example, the intermediate layer 106X described in Embodiment 5 can be used.

[0408] <Example 2 of LSX light source structure>

[0409] The light source LSX described in this embodiment includes electrode 551X, electrode 552X, unit 103X, intermediate layer 106X, unit 103X2, intermediate layer 106X(2), unit 103X3, intermediate layer 106X(3), and unit 103X4 (see reference). Figure 6).

[0410] Unit 103X is located between electrode 552X and electrode 551X, and intermediate layer 106X is located between electrode 552X and unit 103X. Note that unit 103X includes layer 111X, which has the function of emitting light LL1. For example, a structure that emits blue light can be used for unit 103X.

[0411] Unit 103X2 is located between electrode 552X and intermediate layer 106X, and intermediate layer 106X(2) is located between electrode 552X and unit 103X2. Note that unit 103X2 includes layer 111X2, which has the function of emitting light LL2. For example, a structure that emits blue light can be used for unit 103X2.

[0412] Unit 103X3 is located between electrode 552X and intermediate layer 106X(2), and intermediate layer 106X(3) is located between electrode 552X and unit 103X3. Note that unit 103X3 includes layer 111X3, which has the function of emitting light LL3. For example, a structure that emits blue light can be used for unit 103X3.

[0413] Unit 103X4 is located between electrode 552X and intermediate layer 106X(3). Note that unit 103X4 includes layer 111X4, which has the function of emitting light LL4. For example, a structure that emits green light can be used in unit 103X4. Specifically, a phosphorescent material can be used in unit 103X4. This can improve the current efficiency required to emit green light. Furthermore, by making the number of units emitting blue light greater than the number of units emitting green light, the reliability of the light source LSX can be improved.

[0414] <Manufacturing Method of LSX Light Source>

[0415] For example, the layers 551X, 552X, 103X, intermediate layer 106X, and 103X2 can be formed by dry methods, wet methods, vapor deposition, droplet spraying, coating, or printing. Furthermore, the constituent elements can be formed by different methods.

[0416] Specifically, light source LSX can be manufactured using coating equipment such as vacuum evaporation equipment, inkjet equipment, spin coater, gravure printing equipment, offset printing equipment, and screen printing equipment.

[0417] Electrodes can be formed, for example, by a wet process or a sol-gel process using a paste of metallic materials. Alternatively, an indium oxide-zinc oxide film can be formed by sputtering using a target containing 1 wt% to 20 wt% zinc oxide relative to indium oxide. Furthermore, an indium oxide (IWZO) film containing tungsten oxide and zinc oxide can be formed by sputtering using a target containing 0.5 wt% to 5 wt% tungsten oxide and 0.1 wt% to 1 wt% zinc oxide relative to indium oxide.

[0418] This embodiment can be appropriately combined with other embodiments shown in this specification.

[0419] (Implementation Method 7)

[0420] In this embodiment, refer to Figures 7A-11B The structure of a display device according to one aspect of the present invention will be described.

[0421] Figure 7A This is a perspective view illustrating the structure of a display device according to one aspect of the present invention. Figure 7B This is an explanation Figure 7A A partial front view. Furthermore... Figure 8A It is along Figure 7B The cross-sectional view of the cut-off line PQ shown is as follows. Figure 8B It is an explanation and Figure 8A Cross-sectional views of different structures.

[0422] Figure 9A This is a diagram illustrating the emission spectrum of a display device according to one aspect of the present invention. Figure 9B and Figure 9C These are diagrams illustrating the wavelength-transmittance and wavelength-reflectance characteristics of a display device according to one aspect of the present invention. Figure 9D This is a diagram illustrating the wavelength-transmittance characteristics of a display device structure according to one aspect of the present invention.

[0423] Figure 10A This is a diagram illustrating the emission spectrum of a display device according to one aspect of the present invention. Figure 10B and Figure 10C These are diagrams illustrating the wavelength-transmittance and wavelength-reflectance characteristics of a display device according to one aspect of the present invention. Figure 10D This is a diagram illustrating the wavelength-transmittance characteristics of a display device structure according to one aspect of the present invention.

[0424] Figure 11A This is a diagram illustrating the emission spectrum of a display device according to one aspect of the present invention. Figure 11B This is a diagram illustrating the wavelength-transmittance characteristics of a display device structure according to one aspect of the present invention.

[0425] <Example 1 of the structure of display device 700>

[0426] The display device 700 described in this embodiment includes a set of pixels 703 (see reference). Figure 7A In addition, the display device 700 includes a substrate 510 and a functional layer 520.

[0427] A group of pixels 703 includes pixels 702A, 702B, and 702C (see reference). Figure 7B Additionally, a group of pixels 703 includes pixel 702D.

[0428] Pixel 702A includes a light-emitting device 550A and a pixel circuit 530A, with the light-emitting device 550A and the pixel circuit 530A electrically connected (see reference). Figure 8A ).

[0429] Pixel 702B includes a light-emitting device 550B and a pixel circuit 530B, with the light-emitting device 550B and the pixel circuit 530B being electrically connected.

[0430] Pixel 702C includes a light-emitting device 550C and a pixel circuit 530C, with the light-emitting device 550C and the pixel circuit 530C being electrically connected.

[0431] The pixel 702D includes a light-emitting device 550D and a pixel circuit 530D, with the light-emitting device 550D and the pixel circuit 530D being electrically connected.

[0432] The functional layer 520 includes pixel circuits 530A, 530B, and 530C. Furthermore, pixel circuit 530A is sandwiched between light-emitting device 550A and substrate 510, pixel circuit 530B is sandwiched between light-emitting device 550B and substrate 510, and pixel circuit 530C is sandwiched between light-emitting device 550C and substrate 510.

[0433] For example, in a display device 700 according to one aspect of the present invention, the light-emitting device 550A emits light LL in a direction in which no pixel circuit 530A is disposed (see reference). Figure 8A Furthermore, the light-emitting device 550B emits light LL in the direction where the pixel circuit 530B is not configured. Furthermore, the light-emitting device 550C emits light LL in the direction where the pixel circuit 530C is not configured. In other words, one embodiment of the display device 700 of the present invention is a top-emitting type display device.

[0434] Furthermore, for example, in a display device 700 according to one aspect of the present invention, the light-emitting device 550A emits light LL in the direction in which the pixel circuit 530A is arranged (see reference). Figure 8BFurthermore, the light-emitting device 550B emits light LL in the direction where the pixel circuit 530B is configured. Furthermore, the light-emitting device 550C emits light LL in the direction where the pixel circuit 530C is configured. In other words, one embodiment of the display device 700 of the present invention is a bottom-emitting type display device.

[0435] <Light Emitting Device 550A>

[0436] The light-emitting device 550A includes a light source LSA and a conversion unit CUA, with the light source LSA and the conversion unit CUA overlapping. For example, the light-emitting device 550X described in Embodiment 1 can be used for the light-emitting device 550A.

[0437] <<Light Source LSA>>

[0438] The light source LSA illuminates the conversion unit CUA with light LL, and light LL has an emission spectrum that includes blue light (see reference). Figure 9A For example, blue light, light containing both blue and green light, light containing both blue and red light, and white light can be used for light LL.

[0439] <<Example 1 of the structure of a conversion unit CUA>>

[0440] The conversion unit CUA includes a layer CCA and a layer DMA1. The layer CCA is sandwiched between the layer DMA1 and the light source LSA (see reference). Figure 8A ).

[0441] [Layer CCA]

[0442] The CCA layer converts light LL into light LA, which has an emission spectrum that includes red light (see reference). Figure 9A ).

[0443] For example, the CCA layer includes quantum dots. This allows for the display of highly saturated reds.

[0444] [Layer DMA1]

[0445] Layer DMA1 has a reflectivity of 0.8 or higher and 1.0 or lower for light LL, and layer DMA1 has a transmittance of 0.8 or higher and 1.0 or lower for light LA.

[0446] For example, a dielectric multilayer film can be used for layer DMA1. This allows light of a specified wavelength to pass through. Additionally, light of a specified wavelength can be reflected. Furthermore, the full width at half maximum (FWHM) of the transmitted light can be controlled.

[0447] <<Example 2 of the structure of the conversion unit CUA>>

[0448] The conversion unit CUA includes layer DMA2. Layer DMA2 is sandwiched between layer CCA and the light source LSA.

[0449] [Layer DMA2]

[0450] Layer DMA2 has a transmittance of 0.8 or higher and 1.0 or lower for light LL, and a reflectance of 0.8 or higher and 1.0 or lower for red light.

[0451] For example, a dielectric multilayer film can be used for layer DMA2. This allows light of a specified wavelength to pass through. Additionally, light of a specified wavelength can be reflected. Furthermore, the full width at half maximum (FWHM) of the transmitted light can be controlled.

[0452] Therefore, layer DMA2 can reflect the light LA ​​that reaches layer DMA2 through layer CCA back to layer CCA. Furthermore, light LA ​​can be efficiently extracted from the light-emitting device. Additionally, the light LL emitted by the light source LSA can be efficiently converted into light LA. As a result, a novel display device with good convenience, practicality, and reliability can be provided.

[0453] <<Example 3 of the structure of the conversion unit CUA>>

[0454] The conversion unit CUA includes the layer CFA.

[0455] [Layered CFA]

[0456] The CFA layer has a transmittance of greater than 0 and less than 0.2 for LL light, and a transmittance of greater than 0.6 and less than 1.0 for red light. For example, it absorbs blue light and transmits red light. Alternatively, for example, it absorbs both blue and green light and transmits red light.

[0457] Thus, for example, it can be efficiently converted into bright red light. Bright red can be displayed efficiently. As a result, a novel display device with good convenience, practicality, or reliability can be provided.

[0458] <Light-emitting device 550B>

[0459] The light-emitting device 550B includes a light source LSB and a conversion unit CUB, with the light source LSB and the conversion unit CUB overlapping (see reference). Figure 8A For example, the light-emitting device 550X described in Embodiment 1 can be used for the light-emitting device 550B.

[0460] <<Light Source LSB>>

[0461] The light source LSB illuminates the conversion unit CUB with light LL. For example, the same structure as the light source LSA can be used for the light source LSB. Thus, for example, the light source LSB can be formed in the process of forming the light source LSA.

[0462] <<Example 1 of the structure of the conversion unit CUB>>

[0463] The conversion unit CUB includes layer CCB and layer DMB1. Layer CCB is sandwiched between layer DMB1 and the light source LSB.

[0464] [Layer CCB]

[0465] The CCB layer converts light LL into light LB, which has an emission spectrum that includes green light (see reference). Figure 9B ).

[0466] For example, the CCB layer includes quantum dots. This allows for the display of highly saturated green colors.

[0467] [Layer DMB1]

[0468] Layer DMB1 has a reflectivity of 0.8 or higher and 1.0 or lower for light LL, and layer DMB1 has a transmittance of 0.8 or higher and 1.0 or lower for light LB.

[0469] For example, a dielectric multilayer film can be used for layer DMB1. This allows light of a specified wavelength to pass through. Additionally, light of a specified wavelength can be reflected. Furthermore, the full width at half maximum (FWHM) of the transmitted light can be controlled.

[0470] <<Structure Example 2 of the Conversion Unit CUB>>

[0471] The conversion unit CUB includes layer DMB2. Layer DMB2 is sandwiched between layer CCB and the light source LSB.

[0472] [Layer DMB2]

[0473] Layer DMB2 has a transmittance of 0.8 or higher and 1.0 or lower for light LL, and layer DMB2 has a reflectance of 0.8 or higher and 1.0 or lower for green light.

[0474] For example, a dielectric multilayer film can be used for layer DMB2. This allows light of a specified wavelength to pass through. Additionally, light of a specified wavelength can be reflected. Furthermore, the full width at half maximum (FWHM) of the transmitted light can be controlled.

[0475] Therefore, layer DMB2 can reflect the light LB that has passed through layer CCB and reached layer DMB2 back to layer CCB. Furthermore, light LB can be efficiently extracted from the light-emitting device. Additionally, the light LL emitted by the light source LSB can be efficiently converted into light LB. As a result, a novel display device with good convenience, practicality, and reliability can be provided.

[0476] <<Example 3 of the structure of the conversion unit CUB>>

[0477] The conversion unit CUB includes the layer CFB.

[0478] [Layer CFB]

[0479] The CFB layer has a transmittance of greater than 0 and less than 0.2 for LL light, and a transmittance of greater than 0.6 and less than 1.0 for green light. For example, it absorbs blue light and transmits green light. Alternatively, for example, it absorbs both blue and red light and transmits green light.

[0480] Thus, for example, it can be efficiently converted into bright green light. Furthermore, it can display a bright green color. As a result, a novel display device with good convenience, practicality, and reliability can be provided.

[0481] <Example 1 of the structure of the 550C light-emitting device>

[0482] The 550C light-emitting device includes a light source LSC.

[0483] <<Example 1 of the structure of a light source LSC>>

[0484] The light source LSC emits light LL. For example, blue light can be used as the light LL.

[0485] Alternatively, the same structure as the light source LSA can be used for the light source LSC. Thus, for example, the light source LSC can be formed in the process of forming the light source LSA.

[0486] Therefore, the light source LSA, light source LSB, and light source LSC can adopt the same structure. Furthermore, the light source LSA, light source LSB, and light source LSC can be manufactured using the same manufacturing process. This simplifies the manufacturing process of the display device. Additionally, light LL can be efficiently converted into light LA. Furthermore, light LL can be efficiently converted into light LB. Furthermore, for example, blue light can be efficiently converted into green or red light. As a result, a novel display device with good convenience, practicality, and reliability can be provided.

[0487] <Structure Example 2 of Light Emitting Device 550C>

[0488] The light-emitting device 550C includes a conversion unit CUC, and the light source LSC overlaps with the conversion unit CUC (see reference). Figure 8A For example, the light-emitting device 550X described in Embodiment 1 can be used for the light-emitting device 550C.

[0489] <<Example 2 of LSC Light Source Structure>>

[0490] The light source LSC illuminates the conversion unit CUC with light LL, and the light LL has an emission spectrum that includes both blue and green light (see reference). Figure 11A For example, light containing blue and green light, and white light can be used for light LL.

[0491] <<Structure Example of a Conversion Unit (CUC)>>

[0492] The conversion unit CUC includes the layer CFC.

[0493] [CFC layer]

[0494] The CFC layer has a transmittance of greater than 0 and less than 0.2 for green light, and a transmittance of greater than 0.6 and less than 1.0 for blue light. For example, it absorbs green light and transmits blue light. Alternatively, for example, it absorbs both green and red light and transmits blue light.

[0495] This allows for the display of a bright blue color. As a result, a novel display device with good convenience, practicality, and reliability can be provided.

[0496] <Structure Example 2 of Display Device 700>

[0497] One aspect of the present invention is a display device 700 comprising a set of pixels 703 (see reference 700). Figure 7A A group of pixels 703 includes pixels 702A, 702B, 702C, and 702D (see reference). Figure 7B ).

[0498] A group of pixels 703 includes pixel 702D, and pixel 702D includes a light source LSD.

[0499] <<Light Source LSD>>

[0500] The light source LSD emits light LL.

[0501] Therefore, pixels 702D can be used to display blue light. Additionally, for example, hues between blue and green can be displayed. Furthermore, for example, hues between blue and red can be displayed. Moreover, for example, white can be displayed. Furthermore, the energy efficiency of the display device can be improved. As a result, a novel display device with good convenience, practicality, and reliability can be provided.

[0502] Note that this embodiment can be appropriately combined with other embodiments shown in this specification.

[0503] (Implementation Method 8)

[0504] In this embodiment, refer to Figures 12A-12C as well as Figure 13 The structure of a display device according to one aspect of the present invention will be described.

[0505] Figures 12A-12C This is a diagram illustrating the structure of a display device according to one aspect of the present invention. Figure 12A This is a top view of a display device according to one aspect of the present invention. Figure 12B This is an explanation Figure 12A A top view of a portion of it.Figure 12C yes Figure 12A The cross-sectional view of cut-off lines X1-X2, cut-off lines X3-X4, and a group of pixels 703(i,j) is shown.

[0506] Figure 13 This is a circuit diagram illustrating the structure of a display device according to one aspect of the present invention.

[0507] Note that in this specification, variables with integer values ​​greater than 1 are sometimes used as symbols. For example, sometimes (p) of a variable p containing integer values ​​greater than 1 is used as part of the symbol for any one of the maximum number of components. Furthermore, for example, sometimes (m, n) of variables m and n containing integer values ​​greater than 1 is used as part of the symbol for any one of the maximum number of components.

[0508] <Example 1 of the structure of display device 700>

[0509] One embodiment of the display device 700 of the present invention includes region 731 (see reference 731). Figure 12A Region 731 includes a set of pixels 703(i, j).

[0510] <<Example 1 of the structure of a set of pixels 703(i,j)>>

[0511] A group of pixels 703(i,j) includes pixels 702A(i,j), 702B(i,j), and 702C(i,j) (see reference). Figure 12B and Figure 12C ).

[0512] Pixel 702A(i,j) includes pixel circuit 530A(i,j) and light-emitting device 550A. Light-emitting device 550A is electrically connected to pixel circuit 530A(i,j).

[0513] For example, the light-emitting device described in Embodiments 1 to 4 can be used in light-emitting device 550A.

[0514] Furthermore, pixel 702B(i,j) includes pixel circuit 530B(i,j) and light-emitting device 550B, which is electrically connected to pixel circuit 530B(i,j). Similarly, pixel 702C(i,j) includes light-emitting device 550C.

[0515] For example, the structures described in Embodiments 1 to 4 can be used in light-emitting devices 550A and 550B.

[0516] <Structure Example 2 of Display Device 700>

[0517] Furthermore, a display device 700 according to one aspect of the present invention includes a functional layer 540 and a functional layer 520 (see reference 540). Figure 12C Functional layer 540 overlaps with functional layer 520.

[0518] Functional layer 540 includes light-emitting device 550A.

[0519] Functional layer 520 includes pixel circuits 530A(i, j) and wiring (see reference). Figure 12C Pixel circuits 530A(i, j) are electrically connected to wiring. For example, the conductive film provided in the opening 591A of the functional layer 520 can be used as wiring, which electrically connects the terminal 519B and the pixel circuits 530A(i, j). The conductive material CP electrically connects the terminal 519B and the flexible printed substrate FPC1. Furthermore, for example, the conductive film provided in the opening 591B of the functional layer 520 can be used as wiring.

[0520] <Example 3 of the structure of display device 700>

[0521] Furthermore, one embodiment of the display device 700 of the present invention includes a driving circuit GD and a driving circuit SD (see reference). Figure 12A ).

[0522] <<Structure Example of GD Driver Circuit>>

[0523] The drive circuit GD supplies the first selection signal and the second selection signal.

[0524] <<Example of the structure of a driver circuit SD>>

[0525] The drive circuit SD supplies the first control signal and the second control signal.

[0526] <<Examples of Wiring Structures>>

[0527] The wiring includes conductive film G1(i), conductive film G2(i), conductive film S1(j), conductive film S2(j), conductive film ANO, conductive film VCOM2, and conductive film V0 (refer to...). Figure 13 ).

[0528] The conductive film G1(i) is supplied with a first selection signal, and the conductive film G2(i) is supplied with a second selection signal.

[0529] The conductive film S1(j) is supplied with a first control signal, and the conductive film S2(j) is supplied with a second control signal.

[0530] <<Example 1 of the structure of pixel circuit 530A(i,j)>>

[0531] Pixel circuit 530A(i,j) is electrically connected to conductive film G1(i) and conductive film S1(j). Conductive film G1(i) supplies a first selection signal, and conductive film S1(j) supplies a first control signal.

[0532] Pixel circuit 530A(i, j) drives light-emitting device 550A according to first selection signal and first control signal. In addition, light-emitting device 550A emits light.

[0533] One electrode of the light-emitting device 550A is electrically connected to the pixel circuit 530A(i,j), and the other electrode is electrically connected to the conductive film VCOM2.

[0534] <<Example 2 of the structure of pixel circuit 530A(i,j)>>

[0535] The pixel circuit 530A(i,j) includes switch SW21, switch SW22, transistor M21, capacitor C21 and node N21.

[0536] Transistor M21 includes a gate electrode electrically connected to node N21, a first electrode electrically connected to light-emitting device 550A, and a second electrode electrically connected to conductive film ANO.

[0537] The switch SW21 includes a first terminal electrically connected to node N21, a second terminal electrically connected to conductive film S1(j), and a gate electrode having the function of controlling the on state or the off state according to the potential of conductive film G1(i).

[0538] The switch SW22 includes a first terminal electrically connected to the conductive film S2(j) and a gate electrode having the function of controlling the on state or the off state according to the potential of the conductive film G2(i).

[0539] Capacitor C21 includes a conductive film electrically connected to node N21 and a conductive film electrically connected to the second electrode of switch SW22.

[0540] Therefore, image signals can be stored in node N21. Furthermore, the potential of node N21 can be changed using switch SW22. Additionally, the intensity of light emitted by the light-emitting device 550A can be controlled using the potential of node N21. As a result, a novel device with good convenience, practicality, and reliability can be provided.

[0541] <<Example 3 of the structure of pixel circuit 530A(i,j)>>

[0542] The pixel circuit 530A(i,j) includes a switch SW23, a node N22, and a capacitor C22.

[0543] The switch SW23 includes a first terminal electrically connected to the conductive film V0, a ​​second terminal electrically connected to the node N22, and a gate electrode having the function of controlling the on state or the off state according to the potential of the conductive film G2(i).

[0544] Capacitor C22 includes a conductive film electrically connected to node N21 and a conductive film electrically connected to node N22.

[0545] Note that the first electrode of transistor M21 is electrically connected to node N22.

[0546] Note that this embodiment can be appropriately combined with other embodiments shown in this specification.

[0547] (Implementation Method 9)

[0548] In this embodiment, a display module according to one aspect of the present invention is described.

[0549] <Display Module>

[0550] Figure 14 This is a 3D diagram illustrating the structure of the display module 280.

[0551] Display module 280 includes display device 100 and FPC 290 or connector. Display device 100 includes display area 80. For example, the display device described in embodiment 7 can be used for display device 100.

[0552] The FPC290 supplies signals or power to the display device 100 from an external source. Furthermore, an IC can be mounted on the FPC290. A connector is a mechanical component used to electrically connect conductors, allowing the display device 100 to be electrically connected to the component of the connected object. For example, the FPC290 can be used as a conductor. Additionally, the connector allows the display device 100 to be detached from the connected object.

[0553] <<Display Device 100A>>

[0554] Figure 15 This is a cross-sectional view illustrating the structure of the display device 100A. For example, the display device 100A can be used in the display module 280. The substrate 301 corresponds to... Figure 14 Substrate 71 in the middle.

[0555] The display device 100A includes a substrate 301, a transistor 310, a component separation layer 315, an insulating layer 261, a capacitor 240, insulating layers 255 (insulating layers 255a, 255b, and 255c), and multiple light sources 61W. The insulating layer 261 is disposed on the substrate 301A, and the transistor 310 is located between the substrate 301 and the insulating layer 261. The insulating layer 255a is disposed on the insulating layer 261, and the capacitor 240 is located between the insulating layer 261 and the insulating layer 255a. The insulating layer 255a is also located between the multiple light sources 61W and the capacitor 240.

[0556] [Transistor 310]

[0557] Transistor 310 includes a conductive layer 311, a pair of low-resistance regions 312, an insulating layer 313, and an insulating layer 314, with its channel formed in a portion of substrate 301. The conductive layer 311 serves as the gate electrode. The insulating layer 313 is located between substrate 301 and the conductive layer 311 and serves as the gate insulating layer. Substrate 301 has a pair of low-resistance regions 312 doped with impurities. These regions serve as the source and drain. The sides of the conductive layer 311 are covered by the insulating layer 314.

[0558] The component separation layer 315 is embedded in the substrate 301 and located between two adjacent transistors 310.

[0559] [Capacitor 240]

[0560] The capacitor 240 includes a conductive layer 241, a conductive layer 245, and an insulating layer 243, with the insulating layer 243 located between the conductive layers 241 and 245. 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.

[0561] Conductive layer 241 is located on insulating layer 261 and embedded in insulating layer 254. Conductive layer 241 is electrically connected to one of the source and drain terminals of transistor 310 via a connector 275 embedded in insulating layer 261. Insulating layer 243 covers conductive layer 241. Conductive layer 245 overlaps conductive layer 241 through insulating layer 243.

[0562] [Insulation layer 255a, insulation layer 255b and insulation layer 255c]

[0563] The display device 100A includes an insulating layer 255a, an insulating layer 255b and an insulating layer 255c, with the insulating layer 255b located between the insulating layers 255a and 255c.

[0564] [Light source 61W]

[0565] Light source 61W is disposed on insulating layer 255c. Light source 61W can emit blue light, for example. For example, the light source described in Embodiment 1 can be applied to light source 61W. Light source 61W can emit light including blue light. For example, it can emit blue light, light including blue and green light, or white light. In addition, the light-emitting device includes a common layer 174.

[0566] The light source 61W includes a conductive layer 171 and an EL layer 172W, with the EL layer 172W covering the top and side surfaces of the conductive layer 171. Furthermore, a sacrificial layer 270 is located on the EL layer 172W.

[0567] Conductive layer 171 is electrically connected to one of the source and drain terminals of transistor 310 via plug 256 embedded in insulating layers 243, 255a, 255b, and 255c, conductive layer 241 embedded in insulating layer 254, and plug 275 embedded in insulating layer 261. The height of the top surface of insulating layer 255c 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 plug.

[0568] [Protective layer 271, Insulating layer 278, Protective layer 273, Adhesive layer 122]

[0569] The protective layer 271 and the insulating layer 278 are located between adjacent light sources 61W, with the insulating layer 278 disposed on the protective layer 271. In addition, a protective layer 273 is disposed on the light source 61W.

[0570] The adhesive layer 122 bonds the protective layer 273 and the substrate 120 together.

[0571] [Substrate 120]

[0572] Substrate 120 is equivalent to Figure 14 The substrate 73 is located in the substrate 120. For example, a light-shielding layer can be disposed on the side of the adhesive layer 122 of the substrate 120. In addition, various optical components can be disposed on the outer side of the substrate 120.

[0573] The thin film can be used as a substrate. In particular, a thin film with low water absorption can be used appropriately. For example, the water absorption rate is preferably 1% or less, more preferably 0.1% or less. This can suppress dimensional changes in the thin film. Furthermore, the formation of wrinkles and the like can be suppressed. In addition, shape changes in the display device can be suppressed.

[0574] For example, polarizers, phase retardation plates, light diffusion layers (e.g., diffusion films), anti-reflection layers, and condensing films can be used as optical components.

[0575] A circular polarizer can be superimposed on the display device using a substrate made of a material with high optical isotropy, i.e., a material with a phase retardation value of 30 nm or less, preferably 20 nm or less, and more preferably 10 nm or less. For example, cellulose triacetate (TAC, also known as cellulose triacetate) films, cyclic olefin polymer (COP) films, cyclic olefin copolymer (COC) films, and acrylic resin films can be used as films with high optical isotropy.

[0576] Furthermore, surface protective layers such as an antistatic film to inhibit dust adhesion, a water-repellent film to prevent dirt accumulation, a hard coating to inhibit damage during use, and an impact-absorbing layer can also be disposed on the outer side of the substrate 120. For example, a glass layer or a silicon dioxide layer (SiO2) can be used. x Layers), DLC (diamond-like carbon), aluminum oxide (AlO) x Materials such as polyesters or polycarbonates can be used for the surface protective layer. Additionally, materials with high visible light transmittance can be appropriately used for the surface protective layer. Furthermore, materials with high hardness can be appropriately used for the surface protective layer.

[0577] Additionally, the display device 100A includes a conversion unit 183R, a conversion unit 183G, and a conversion unit 183B. Conversion unit 183B overlaps with a light source 61W, and conversion unit 183G overlaps with other light sources 61W. The conversion unit also has an area overlapping with other light sources 61W. Conversion unit 183R includes a CCR layer and a DMR layer. The CCR layer includes quantum dots, and the DMR layer includes a dielectric multilayer film. Conversion unit 183G includes a CCG layer and a DMG layer. The CCG layer includes quantum dots, and the DMG layer includes a dielectric multilayer film. Furthermore, the display device 100A includes a gap 276 between the light-emitting device and the conversion unit.

[0578] Thus, for example, conversion unit 183R converts the light emitted by light source 61W into red light, conversion unit 183G converts the light emitted by light source 61W into green light, and conversion unit 183B allows the blue light contained in the light emitted by light source 61W to pass through.

[0579] <<Display Device 100C>>

[0580] Figure 16 This is a cross-sectional view illustrating the structure of the display device 100C. The display device 100C can, for example, be used in the display module 280 (see reference 100). Figure 14 Note that in the following description of the display device, parts that are the same as those described previously are sometimes omitted.

[0581] The display device 100C includes a substrate 301B and a substrate 301A. The display device 100C includes a transistor 310B, a capacitor 240, a plurality of light sources 61W, and a transistor 310A. The channel of the transistor 310A is formed in a portion of the substrate 301A, and the channel of the transistor 310B is formed in a portion of the substrate 301B.

[0582] [Insulation layer 345, Insulation layer 346]

[0583] Insulating layer 345 is in contact with the bottom surface of substrate 301B, and insulating layer 346 is located on insulating layer 261. For example, an inorganic insulating film that can be used for protective layer 273 can be used as insulating layer 345 and insulating layer 346. Insulating layer 345 and insulating layer 346 are used as protective layers and can suppress the diffusion of impurities to substrate 301B and substrate 301A.

[0584] [Plug 343]

[0585] The plug 343 passes through the substrate 301B and the insulating layer 345. The insulating layer 344 covers the sides of the plug 343. For example, an inorganic insulating film that can be used for the protective layer 273 can be used as the insulating layer 344. The insulating layer 344 serves as a protective layer and can inhibit the diffusion of impurities into the substrate 301B.

[0586] [Conductive layer 342]

[0587] The conductive layer 342 is located between the insulating layers 345 and 346. Furthermore, preferably, the conductive layer 342 is embedded within the insulating layer 335, and the surface formed by the conductive layer 342 and the insulating layer 335 is planarized. The conductive layer 342 is electrically connected to the plug 343.

[0588] [Conductive layer 341]

[0589] The conductive layer 341 is located between the insulating layer 346 and the insulating layer 335. Furthermore, preferably, the conductive layer 341 is embedded within the insulating layer 336, and the surface formed by the conductive layer 341 and the insulating layer 336 is planarized. The conductive layer 341 is bonded to the conductive layer 342. Thus, substrate 301A and substrate 301B are electrically connected.

[0590] The conductive layer 341 is preferably made of the same conductive material as the conductive layer 342. For example, a metal film containing elements selected from Al, Cr, Cu, Ta, Ti, Mo, and W, or a metal nitride film (e.g., titanium nitride film, molybdenum nitride film, or tungsten nitride film) composed of the aforementioned elements can be used. Copper is particularly preferred as both the conductive layer 341 and the conductive layer 342. This allows for the use of Cu-Cu (copper-copper) direct bonding technology (a technology that enables electrical conduction by connecting Cu (copper) pads to each other).

[0591] <<Display Device 100D>>

[0592] Figure 17 This is a cross-sectional view illustrating the structure of the display device 100D. The display device 100D can, for example, be used in the display module 280 (see reference 100). Figure 14 ).

[0593] The display device 100D has bumps 347 that bond conductive layers 341 and 342. Furthermore, the bumps 347 electrically connect conductive layers 341 and 342. For example, conductive materials including gold (Au), nickel (Ni), indium (In), or tin (Sn) can be used for the bumps 347. Additionally, solder can be used for the bumps 347, for example.

[0594] In addition, the display device 100D includes an adhesive layer 348. The adhesive layer 348 bonds the insulating layer 345 and the insulating layer 346 together.

[0595] <<Display Device 100E>>

[0596] Figure 18 This is a cross-sectional view illustrating the structure of the display device 100E. The display device 100E can, for example, be used in the display module 280 (see reference 100). Figure 14 Substrate 331 is equivalent to Figure 14 Substrate 71. An insulating substrate or a semiconductor substrate may be used for substrate 331. Display device 100E includes transistor 320. The transistors of display device 100E are OS transistors, which differs from display device 100A.

[0597] [Insulation layer 332]

[0598] An insulating layer 332 is disposed on the substrate 331. For example, a film that makes it less susceptible to hydrogen or oxygen diffusion compared to a silicon oxide film can be used for the insulating layer 332. Specifically, an aluminum oxide film, a hafnium oxide film, or a silicon nitride film can be used for the insulating layer 332. Thus, the insulating layer 332 can prevent impurities such as water or hydrogen from diffusing from the substrate 331 to the transistor 320. Furthermore, it can prevent oxygen from escaping from the semiconductor layer 321 towards the insulating layer 332.

[0599] [Transistor 320]

[0600] Transistor 320 includes a semiconductor layer 321, an insulating layer 323, a conductive layer 324, a pair of conductive layers 325, an insulating layer 326, and a conductive layer 327.

[0601] A conductive layer 327 is disposed on the insulating layer 332 and serves as the first gate electrode of the transistor 320. An insulating layer 326 covers the conductive layer 327. A portion of the insulating layer 326 serves as the first gate insulating layer. The insulating layer 326 includes an oxide insulating film at least in the region in contact with the semiconductor layer 321. Specifically, a silicon oxide film or the like is preferably used. Furthermore, the insulating layer 326 has a planarized top surface. A semiconductor layer 321 is disposed on the insulating layer 326. A metal oxide film with semiconductor properties can be used for the semiconductor layer 321. A pair of conductive layers 325 contact the semiconductor layer 321 and serve as the source electrode and drain electrode.

[0602] [Insulation layer 328, Insulation layer 264]

[0603] An insulating layer 328 covers the top and side surfaces of a pair of conductive layers 325 and the side surface of the semiconductor layer 321. An insulating layer 264 is disposed on the insulating layer 328 and serves as an interlayer insulating layer. Furthermore, both the insulating layers 328 and 264 have openings that extend to the semiconductor layer 321. For example, the same insulating film as the insulating layer 332 can be used as the insulating layer 328. Thus, the insulating layer 328 can, for example, prevent impurities such as water or hydrogen from diffusing from the insulating layer 264 to the semiconductor layer 321. Furthermore, it can prevent oxygen from detaching from the semiconductor layer 321.

[0604] [Insulation layer 323]

[0605] The insulating layer 323 is in contact with the sides of the insulating layer 264, the insulating layer 328 and the conductive layer 325 and the top surface of the semiconductor layer 321 inside the opening.

[0606] [Conductive layer 324]

[0607] The conductive layer 324 is embedded inside the opening in a manner that contacts the insulating layer 323. The conductive layer 324 has a planarized top surface, the height of which is the same as or substantially the same as the top surface of the insulating layer 323 and the top surface of the insulating layer 264. The conductive layer 324 is used as the second gate electrode, and the insulating layer 323 is used as the second gate insulating layer.

[0608] [Insulation layer 329, Insulation layer 265]

[0609] Insulating layer 329 covers conductive layer 324, insulating layer 323, and insulating layer 264. Insulating layer 265 is disposed on insulating layer 329 and serves as an interlayer insulating layer. For example, the same insulating film as insulating layers 328 and 332 can be used as insulating layer 329. This prevents impurities such as water or hydrogen from diffusing from insulating layer 265 into transistor 320.

[0610] [Plug 274]

[0611] The plug 274 is embedded in insulating layers 265, 329, 264, and 328 and is electrically connected to one of a pair of conductive layers 325. The plug 274 includes conductive layers 274a and 274b. Conductive layer 274a contacts the side surfaces of openings in insulating layers 265, 329, 264, and 328. It also covers a portion of the top surface of conductive layer 325. Conductive layer 274b contacts the top surface of conductive layer 274a. For example, a conductive material that does not readily diffuse with hydrogen and oxygen can be suitably used for conductive layer 274a.

[0612] <<Display Device 100F>>

[0613] Figure 19 This is a cross-sectional view illustrating the structure of the display device 100F. The display device 100F has a structure in which transistors 320A and 320B are stacked. Both transistors 320A and 320B contain oxide semiconductors, and their channels are formed in the oxide semiconductors. Note that the structure is not limited to stacking two transistors; for example, a structure in which three or more transistors are stacked can also be used.

[0614] The structure of transistor 320A and its vicinity is the same as that of transistor 320 and its vicinity in the display device 100E described above. The structure of transistor 320B and its vicinity is the same as that of transistor 320 and its vicinity in the display device 100E described above.

[0615] <<Display Device 100G>>

[0616] Figure 20 This is a cross-sectional view illustrating the structure of the display device 100G. The display device 100G has a structure in which transistors 310 and 320 are stacked. The channel of transistor 310 is formed in substrate 301. Furthermore, transistor 320 comprises an oxide semiconductor, and its channel is formed in the oxide semiconductor.

[0617] An insulating layer 261 covers the transistor 310, and a conductive layer 251 is disposed on the insulating layer 261. An insulating layer 262 covers the conductive layer 251, and a conductive layer 252 is disposed on the insulating layer 262. Furthermore, insulating layers 263 and 332 cover the conductive layer 252. In addition, both conductive layers 251 and 252 are used for wiring.

[0618] Transistor 320 is disposed on insulating layer 332, and insulating layer 265 covers transistor 320. In addition, capacitor 240 is disposed on insulating layer 265, and capacitor 240 is electrically connected to transistor 320 via connector 274.

[0619] For example, transistor 320 can be used as a transistor constituting a pixel circuit. Furthermore, transistor 310 can be used as a transistor constituting a pixel circuit or as a driving circuit (gate driver circuit or source driver circuit, etc.) to drive the pixel circuit. Additionally, transistors 310 and 320 can be used in various circuits such as arithmetic circuits or memory circuits. Thus, for example, a driving circuit can be configured directly under the light-emitting device in addition to the pixel circuit. Furthermore, compared to a structure where the driving circuit is placed near the display area, the display device can be further miniaturized.

[0620] At least a portion of this embodiment can be implemented in combination with other embodiments described in this specification.

[0621] (Implementation Method 10)

[0622] In this embodiment, a display module according to one aspect of the present invention will be described.

[0623] <Display Module>

[0624] Figure 21 It is a 3D diagram illustrating the structure of the display module.

[0625] The display module includes a display device 100, an IC (integrated circuit) 176, and an FPC 177 or a connector. For example, the display device described in Embodiment 7 can be used in the display device 100.

[0626] Display device 100 is electrically connected to IC176 and FPC177. FPC177 supplies signals and power to display device 100 from an external source. A connector is a mechanical part that electrically connects conductors, allowing display device 100 to be electrically connected to a component of a connected object. For example, FPC177 can be used as a conductor. Furthermore, the connector allows display device 100 to be detached from the connected object.

[0627] The display module includes IC176. For example, IC176 can be disposed on substrate 14b using a COG method or the like. Alternatively, IC176 can be disposed on an FPC using a COF (Chip On Film) method or the like. For example, gate driver circuitry or source driver circuitry can be used for IC176.

[0628] <<Display Device 100H>>

[0629] Figure 22A This is a cross-sectional view illustrating the structure of the display device 100H.

[0630] The display device 100H includes a display portion 37b, a connecting portion 140, a circuit 164, and wiring 165, etc. The display device 100H includes a substrate 16b and a substrate 14b, which are bonded together. The display device 100H includes one or more connecting portions 140. The connecting portions 140 can be disposed on the outer side of the display portion 37b. For example, the connecting portion 140 can be disposed along one side of the display portion 37b. Alternatively, it can be disposed around multiple sides, such as four sides. In the connecting portion 140, a common electrode of a light-emitting device is electrically connected to a conductive layer, which supplies a predetermined potential to the common electrode.

[0631] Wiring 165 is supplied with signals and power from FPC177 or IC176. Wiring 165 supplies signals and power to display unit 37b and circuit 164.

[0632] For example, the gate driver circuit can be used as circuit 164.

[0633] The display device 100H includes a substrate 14b, a substrate 16b, a transistor 201, a transistor 205, and multiple light sources 63W, etc. (see reference) Figure 22A ).

[0634] The 63W light source can emit light that includes blue light. For example, the 63W light source can emit blue light, light that includes both blue and green light, or white light.

[0635] The display device 100H includes a conversion unit 183R, a conversion unit 183G, and a conversion unit 183B.

[0636] [Conversion Unit 183R, Conversion Unit 183G, and Conversion Unit 183B]

[0637] Conversion unit 183R is located between a light source 63W and a substrate 16b, conversion unit 183G is located between another light source 63W and the substrate 16b, and conversion unit 183B is located between another light source 63W and the substrate 16b. Conversion unit 183R includes a CCR layer and a DMR layer. The CCR layer includes quantum dots, and the DMR layer includes a dielectric multilayer film. Conversion unit 183G includes a CCG layer and a DMG layer. The CCG layer includes quantum dots, and the DMG layer includes a dielectric multilayer film. Furthermore, conversion unit 183B contains a coloring material and is used as a color filter.

[0638] Thus, for example, conversion unit 183R converts the light emitted by light source 63W into red light 83R and transmits it, conversion unit 183G converts the light emitted by light source 63W into green light 83G and transmits it, and conversion unit 183B transmits the blue light 83B contained in the light emitted by light source 63W. Thus, display device 100H can perform full-color display.

[0639] Furthermore, various optical components can be disposed on the outer side of the substrate 16b. For example, polarizers, retardation plates, light diffusion layers (e.g., diffusion films), anti-reflection layers, and light-concentrating films can be disposed.

[0640] The light source 63W includes a conductive layer 171 and an EL layer 172W. For example, the light source described in Embodiment 1 can be used for the light source 63W.

[0641] The light-emitting device includes a conductive layer 171, which serves as a pixel electrode. The conductive layer 171 has a recess that overlaps with openings provided in insulating layers 214, 215, and 213. Furthermore, the transistor 205 includes a conductive layer 222b, which is electrically connected to the conductive layer 171.

[0642] The display device 100H includes an insulating layer 272. The insulating layer 272 covers the ends of the conductive layer 171 and fills the recesses of the conductive layer 171 (see reference). Figure 22A ).

[0643] The display device 100H includes a protective layer 273 and an adhesive layer 142. The protective layer 273 covers multiple light sources 63W. The adhesive layer 142 bonds the protective layer 273 to the substrate 16b. The adhesive layer 142 fills the space between the substrate 16b and the protective layer 273. Alternatively, for example, the adhesive layer 142 can be formed in a frame shape without overlapping the light sources, and the area surrounded by the adhesive layer 142, the substrate 16b, and the protective layer 273 can be filled with a resin different from that used for the adhesive layer 142. Alternatively, an inert gas (such as nitrogen or argon) can be used to fill the space, i.e., a hollow sealed structure can be adopted. For example, a material suitable for the adhesive layer 122 can be applied to the adhesive layer 142.

[0644] The display device 100H includes a connection portion 140, which includes a conductive layer 168. The conductive layer 168 is supplied with a power supply potential. Furthermore, a light-emitting device includes a conductive layer 173, which is electrically connected to the conductive layer 168 and is also supplied with a power supply potential. The conductive layer 173 serves as a common electrode. Alternatively, for example, a conductive film can be fabricated to form both the conductive layer 171 and the conductive layer 168.

[0645] Display device 100H is a top-emitting display device. The light source emits light toward the substrate 16b. The conductive layer 171 contains a material that reflects visible light, and the conductive layer 173 transmits visible light.

[0646] [Insulating layer 211, insulating layer 213, insulating layer 215, insulating layer 214]

[0647] Insulating layers 211, 213, 215, and 214 are sequentially disposed on substrate 14b. Note that there is no limit to the number of insulating layers; they can be a single layer or two or more layers.

[0648] For example, inorganic insulating films can be used as insulating layers 211, 213, and 215. For example, silicon nitride films, silicon oxynitride films, silicon oxide films, silicon oxynitride films, aluminum oxide films, or aluminum nitride films can be used. Furthermore, hafnium oxide films, yttrium oxide films, zirconium oxide films, gallium oxide films, tantalum oxide films, magnesium oxide films, lanthanum oxide films, cerium oxide films, or neodymium oxide films can also be used. In addition, two or more of the above insulating films can be laminated.

[0649] Insulating layers 215 and 214 cover the transistor. Insulating layer 214 serves as a planarization layer. For example, it is preferable to use a material that does not readily diffuse impurities such as water and hydrogen for insulating layer 215 or insulating layer 214. This effectively suppresses the diffusion of impurities from the outside into the transistor. Furthermore, it improves the reliability of the display device.

[0650] For example, an organic insulating layer can be suitable as the insulating layer 214. Specifically, acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimide amide resin, silicone resin, benzocyclobutene resin, phenolic resin, and precursors of the above resins can be used as the organic insulating layer. Furthermore, a laminated structure of organic and inorganic insulating layers can be used for the insulating layer 214. Thus, the outermost surface layer of the insulating layer 214 can be used as an etching protection layer. For example, when it is desired to prevent the formation of recesses in the insulating layer 214 when the conductive layer 171 is processed into a predetermined shape, this phenomenon can be suppressed.

[0651] [Transistor 201, Transistor 205]

[0652] Transistor 201 and transistor 205 are both formed on substrate 14b. These transistors can be manufactured using the same materials and the same process.

[0653] Transistors 201 and 205 include a conductive layer 221, an insulating layer 211, conductive layers 222a and 222b, a semiconductor layer 231, an insulating layer 213, and a conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The conductive layer 221 serves as the gate, and the insulating layer 211 serves as the first gate insulating layer. The conductive layers 222a and 222b serve as the source and drain, respectively. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231. The conductive layer 223 serves as the gate, and the insulating layer 213 serves as the second gate insulating layer. Here, multiple layers obtained by processing the same conductive film are covered with the same shaded lines.

[0654] There are no particular limitations on the structure of the transistors included in the display 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.

[0655] 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 together, and the transistor can be driven by supplying the same signal to both gates. 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 a potential to drive the transistor to the other.

[0656] There are no particular restrictions on the crystallinity of the semiconductor layer of the transistor; amorphous semiconductors, crystalline semiconductors (microcrystalline semiconductors, polycrystalline semiconductors, single-crystal semiconductors, or semiconductors in which a portion has crystalline regions) can be used. Using crystalline semiconductors can suppress the degradation of transistor characteristics, making them preferred.

[0657] The semiconductor layer of the transistor preferably comprises a metal oxide. That is, the transistors included in the display device of this embodiment preferably use OS transistors.

[0658] [Semiconductor layer]

[0659] For example, indium oxide, gallium oxide, and zinc oxide can be used in the semiconductor layer. Furthermore, the metal oxide preferably comprises two or three selected from indium, element M, and zinc. Note that element M is selected from one or more of gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, cobalt, and magnesium. In particular, element M is preferably selected from one or more of aluminum, gallium, yttrium, and tin.

[0660] In particular, as the metal oxide used for 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 (also denoted as ITZO (registered trademark)) 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.

[0661] When the metal oxide used for the semiconductor layer is an In-M-Zn oxide, the atomic ratio of In in the In-M-Zn oxide is preferably greater than or equal to the atomic ratio of M. Examples of such atomic ratios of metal elements in the 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 = 1:3:2 or similar; In:M:Zn = 1:3:4 or similar; In:M:Zn = 2:1:3 or similar; In:M:Zn = 3:1:2 or similar; In:M: Compositions with 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. Note that "simultaneous" composition includes a range of ±30% of the desired atomic number ratio.

[0662] For example, when the atomic number ratio is described as In:Ga:Zn = 4:2:3 or similar, the following cases are included: 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 number ratio is described as In:Ga:Zn = 5:1:6 or similar, the following cases are included: when In is 5, Ga is greater than 0.1 and 2 or less, and Zn is 5 or more and 7 or less. Moreover, when the atomic number ratio is described as In:Ga:Zn = 1:1:1 or similar, the following cases are included: 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.

[0663] The semiconductor layer may also comprise two or more metal oxide layers with different compositions. For example, a stacked structure may be suitable, consisting of a first metal oxide layer with an In:M:Zn ratio of 1:3:4 or similar, and a second metal oxide layer disposed on the first metal oxide layer with an In:M:Zn ratio of 1:1:1 or similar. Furthermore, gallium or aluminum is particularly preferred as element M.

[0664] For example, a stacked structure selected from any one of indium oxide, indium gallium oxide and IGZO, and any one of IAZO, IAGZO and ITZO (registered trademark) can also be used.

[0665] Examples of crystalline oxide semiconductors include CAAC (c-axis-aligned crystalline)-OS and nc (nanocrystalline)-OS.

[0666] 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, and amorphous silicon. In particular, transistors containing low-temperature polysilicon (LTPS) in the semiconductor layer (also known as LTPS transistors) can be used. LTPS transistors have high field-effect mobility and good frequency characteristics.

[0667] By using Si transistors such as LTPS transistors, circuits requiring high-frequency driving (e.g., data driver circuits) and display sections can be formed on the same substrate. Therefore, the external circuitry mounted to the display device can be simplified, reducing component and installation costs.

[0668] OS transistors have a much higher field-effect mobility than transistors using amorphous silicon. Furthermore, OS transistors exhibit extremely low source-drain leakage current (also known as off-state current) 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 display devices.

[0669] Furthermore, increasing the luminous brightness of a light-emitting device requires increasing the current flowing through it. This necessitates increasing 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 higher voltage can be applied between the source and drain of the OS transistor. Therefore, by using an OS transistor as the driving transistor in the pixel circuit, the current flowing through the light-emitting device can be increased, thereby improving its luminous brightness.

[0670] Furthermore, when driven in the saturation region, OS transistors, compared to Si transistors, allow for smaller variations in the source-drain current as the gate-source voltage changes. Therefore, by using OS transistors as driving transistors included in pixel circuits, the current flowing through the source-drain junction can be precisely determined by controlling the gate-source voltage. This allows control over the amount of current flowing through the light-emitting device. Consequently, the number of gray levels represented by the pixel circuit can be increased.

[0671] Furthermore, regarding the saturation characteristics of the current flowing through a transistor when driven 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 an OS transistor is driven in the saturation region, the source-drain current remains almost unchanged even when the source-drain voltage is increased. This allows for stable luminous intensity of the light-emitting device.

[0672] As described above, by using OS transistors as driving transistors included in pixel circuits, it is possible to achieve suppression of black impurities, increase of light emission brightness, multi-grayscale scaling, and suppression of light emission device non-uniformity.

[0673] The transistors included in circuit 164 and the transistors included in display unit 107 can have the same structure or different structures. Similarly, the multiple transistors included in circuit 164 can have the same structure or two or more different structures.

[0674] All transistors included in the display unit 107 may be OS transistors or Si transistors. Alternatively, some transistors included in the display unit 107 may be OS transistors and the remaining transistors may be Si transistors.

[0675] For example, by using both LTPS transistors and OS transistors in the display section 107, a display 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 the OS transistor as a switch used for controlling the on / off state of the wiring and the LTPS transistor as a transistor for controlling the current.

[0676] For example, one of the transistors included in the display unit 107 is used as a transistor to control the current flowing through the light-emitting device, and can be called 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 can be increased.

[0677] On the other hand, one of the other transistors included in the display unit 107 is used as a switch to control the selection and non-selection of pixels, and can also be referred to as a selection transistor. The gate of the selection transistor is electrically connected to the gate line, and one of the source and drain is electrically connected to the signal line. An OS transistor is preferably used as the selection transistor. Therefore, even with a significantly low frame rate (e.g., below 1 fps), the grayscale level of the pixels can be maintained, thereby reducing power consumption by stopping the driver when displaying a static image.

[0678] Thus, a display device according to one aspect of the present invention can simultaneously possess high aperture ratio, high definition, high display quality, and low power consumption.

[0679] One aspect of the present invention provides a display device comprising an OS transistor and a light-emitting device having an MML structure. By employing this structure, leakage current flowing through the transistor and leakage current flowing between adjacent light-emitting devices can be extremely low. Furthermore, by employing the above structure, when an image is displayed on the display 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 transverse leakage current between light-emitting devices, for example, a display with minimal light leakage (so-called impure black) that may occur when displaying black can be achieved.

[0680] In particular, the MML structure of the light-emitting device can make the current flowing between adjacent light-emitting devices extremely low.

[0681] [Transistor 209, Transistor 210]

[0682] Figure 22B and Figure 22C This is a cross-sectional view illustrating another example of the cross-sectional structure of a transistor that can be used in the display device 100H.

[0683] Transistors 209 and 210 include a conductive layer 221, an insulating layer 211, a semiconductor layer 231, conductive layers 222a and 222b, an insulating layer 225, a conductive layer 223, and an insulating layer 215. The semiconductor layer 231 has a channel forming region 231i and a pair of low-resistance regions 231n. The insulating layer 211 is located between the conductive layer 221 and the channel forming region 231i. The conductive layer 221 serves as the gate, and the insulating layer 211 serves as a first gate insulating layer. The insulating layer 225 is located at least between the conductive layer 223 and the channel forming region 231i. The conductive layer 223 serves as the gate, and the insulating layer 225 serves as a second gate insulating layer. The conductive layer 222a is electrically connected to one of the pair of low-resistance regions 231n, and the conductive layer 222b is electrically connected to the other of the pair of low-resistance regions 231n. The insulating layer 215 covers the conductive layer 223. The insulating layer 218 also covers the transistor.

[0684] [Example 1 of the structure of insulating layer 225]

[0685] In transistor 209, insulating layer 225 covers the top and side surfaces of semiconductor layer 231 (see reference). Figure 22B Insulating layers 225 and 215 have openings in which conductive layers 222a and 222b are electrically connected to the low-resistance region 231n. Furthermore, one of conductive layers 222a and 222b is used as a source, and the other as a drain.

[0686] [Structural Example 2 of Insulation Layer 225]

[0687] In transistor 210, the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231 but not with the low-resistance region 231n (see reference). Figure 22C For example, conductive layer 223 can be used as a mask to process insulating layer 225 into a specified shape. Insulating layer 215 covers insulating layer 225 and conductive layer 223. In addition, insulating layer 215 has an opening, and conductive layers 222a and 222b are electrically connected to low-resistance region 231n.

[0688] [Connecting part 204]

[0689] A connection portion 204 is disposed on the substrate 14b. The connection portion 204 includes a conductive layer 166, which is electrically connected to the wiring 165. The connection portion 204 does not overlap with the substrate 16b, and the conductive layer 166 is exposed. A conductive film can be fabricated to form the conductive layer 166 and the conductive layer 171. Furthermore, the conductive layer 166 is electrically connected to the FPC 177 via a connection layer 242. For example, anisotropic conductive film (ACF) or anisotropic conductive paste (ACP) can be used as the connection layer 242.

[0690] <<Display Device 100I>>

[0691] Figure 23 This is a cross-sectional view illustrating the structure of display device 100I. Display device 100I differs from display device 100H in that it is flexible. In other words, display device 100I is a flexible display. Display device 100I includes a substrate 17 replacing substrate 14b and a substrate 18 replacing substrate 16b. Both substrate 17 and substrate 18 are flexible.

[0692] The display device 100I includes an adhesive layer 156 and an insulating layer 162. The adhesive layer 156 bonds the insulating layer 162 to a substrate 17. For example, a material suitable for the adhesive layer 122 can be applied to the adhesive layer 156. Furthermore, for example, a material suitable for insulating layers 211, 213, or 215 can be used for the insulating layer 162. Transistors 201 and 205 are disposed on the insulating layer 162.

[0693] For example, an insulating layer 162 is formed on a manufacturing substrate, and transistors and light-emitting devices are formed on the insulating layer 162. Next, for example, an adhesive layer 142 is formed on the light-emitting device, and the manufacturing substrate is bonded to the substrate 18 using the adhesive layer 142. Next, the manufacturing substrate is separated from the insulating layer 162, exposing the surface of the insulating layer 162. Then, an adhesive layer 156 is formed on the exposed surface of the insulating layer 162, and the insulating layer 162 is bonded to the substrate 17 using the adhesive layer 156. Thus, the constituent elements formed on the manufacturing substrate can be transferred to the substrate 17 to manufacture the display device 100I.

[0694] <<Display Device 100J>>

[0695] Figure 24 This is a cross-sectional view illustrating the structure of display device 100J. The difference between display device 100J and display device 100H is that display device 100J has a continuous EL layer 172W between adjacent light sources 63W, instead of a separate EL layer 172W between adjacent light sources 63W.

[0696] The display device 100J includes a conversion unit 183R, a conversion unit 183G, and a conversion unit 183B located between substrates 16b and 14b. The conversion unit 183R overlaps with a light source 63W, the conversion unit 183G overlaps with another light source 63W, and the conversion unit 183B overlaps with another light source 63W.

[0697] The display device 100J includes a light-shielding layer 117. For example, it includes a light-shielding layer 117 located between the conversion unit 183R and the conversion unit 183G, between the conversion unit 183G and the conversion unit 183B, and between the conversion unit 183B and the conversion unit 183R. In addition, the light-shielding layer 117 includes a region that overlaps with the connection portion 140 and a region that overlaps with the circuit 164.

[0698] The light source 63W can, for example, emit blue light. Furthermore, for example, conversion unit 183R converts the light emitted by the light source 63W into red light, conversion unit 183G converts the light emitted by the light source 63W into green light, and conversion unit 183B transmits the blue light emitted by the light source 63W. Thus, the display device 100J can, for example, emit red light 83R, green light 83G, and blue light 83B to perform a full-color display.

[0699] <<Display Device 100K>>

[0700] Figure 25 This is a cross-sectional view illustrating the structure of display device 100K. The difference between display device 100K and display device 100H is that display device 100K is a bottom-emitting display device. The light-emitting device emits light onto the substrate 14b side, and display device 100K emits light 83R, light 83G, and light 83B from the substrate 14b side. A material that transmits visible light is used in conductive layer 171. Furthermore, a material that reflects visible light is used in conductive layer 173.

[0701] The display device 100K includes a conversion unit 183R, a conversion unit 183G, and a conversion unit 183B. Furthermore, the display device 100K includes a light-shielding layer 117.

[0702] [Conversion Unit 183R, Conversion Unit 183G, and Conversion Unit 183B]

[0703] Conversion unit 183R is located between one light source 63W and substrate 14b, conversion unit 183G is located between another light source 63W and substrate 14b, and conversion unit 183B is located between yet another light source 63W and substrate 14b. For example, conversion units 183R, 183G, and 183B can be disposed between insulating layer 215 and insulating layer 214. Conversion unit 183R includes a CCR layer and a DMR layer. The CCR layer includes quantum dots, and the DMR layer includes a dielectric multilayer film. Conversion unit 183G includes a CCG layer and a DMG layer. The CCG layer includes quantum dots, and the DMG layer includes a dielectric multilayer film.

[0704] [Light-shielding layer 117]

[0705] A light-shielding layer 117 is disposed on the substrate 14b and is located between the substrate 14b and the transistor 205. Furthermore, an insulating layer 153 is located between the light-shielding layer 117 and the transistor 205. For example, the light-shielding layer 117 does not overlap with the light-emitting area of ​​the light source 63W. Additionally, for example, the light-shielding layer 117 overlaps with the connection portion 140 and the circuit 164.

[0706] The light-shielding layer 117 can also be provided in the display device 100L or the display device 100M. In this case, the light emitted by the light source 63W can be suppressed from being reflected by the substrate 14b and diffused inside the display device 100K or the display device 100L. Thus, the display device 100L and the display device 100M can be display devices with high display quality.

[0707] <<Display Device 100L>>

[0708] Figure 26 This is a cross-sectional view illustrating the structure of display device 100L. Display device 100L differs from display device 100H in that it is flexible and is a bottom-emitting display device. Display device 100L includes substrate 17 instead of substrate 14b, and substrate 18 instead of substrate 16b. Both substrate 17 and substrate 18 are flexible. A light-emitting device emits light onto one side of substrate 17, and display device 100L emits light 83R, light 83G, and light 83B from one side of substrate 17.

[0709] Furthermore, conductive layers 221 and 223 can be both transparent and reflective of visible light. When conductive layers 221 and 223 are transparent to visible light, the visible light transmittance of the display unit 107 can be increased. On the other hand, when conductive layers 221 and 223 are reflective of visible light, the amount of visible light incident on the semiconductor layer 231 can be reduced. In addition, damage to the semiconductor layer 231 can be reduced. As a result, the reliability of the display device 100K or the display device 100L can be improved.

[0710] Note that even when using a top-emitting display device such as display device 100H or display device 100I, at least a portion of the layer constituting transistor 205 can be transparent to visible light. In this case, conductive layer 171 is also transparent to visible light. As described above, the visible light transmittance of display section 107 can be improved.

[0711] <<Display Device 100M>>

[0712] Figure 27 This is a cross-sectional view illustrating the structure of display device 100M. The difference between display device 100M and display device 100H is that display device 100M has a structure in which the EL layers 172W are continuous between adjacent light sources 63W instead of a structure in which each EL layer 172W is separate; and display device 100M is a bottom-emitting type display device.

[0713] The display device 100M includes a conversion unit 183R, a conversion unit 183G, and a conversion unit 183B. Furthermore, the display device 100M includes a light-shielding layer 117.

[0714] [Light-shielding layer 117]

[0715] A light-shielding layer 117 is disposed on the substrate 16b, and the light-shielding layer 117 includes an opening in the region overlapping with the light source 63W. For example, the light-shielding layer 117 is included between conversion units 183R and 183G, between conversion units 183G and 183B, and between conversion units 183B and 183R. In addition, the light-shielding layer 117 includes a region overlapping with the connection portion 140 and a region overlapping with the circuit 164.

[0716] At least a portion of this embodiment can be implemented in combination with other embodiments described in this specification.

[0717] (Implementation Method 11)

[0718] In this embodiment, an electronic device according to one aspect of the present invention will be described.

[0719] The electronic device of this embodiment includes a display device according to one aspect of the present invention in its display unit. The display 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.

[0720] As electronic devices, in addition to large-screen electronic devices such as television sets, desktop or laptop personal computers, computer monitors, digital signage, and large game machines such as pinball machines, examples include digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, portable information terminals, and sound reproduction devices.

[0721] In particular, because the display device of one aspect of the present invention can improve clarity, it can be suitably used in electronic devices that include a smaller 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 such as head-mounted displays for VR, glasses-type AR devices, and MR devices.

[0722] The display device of one aspect of the present invention preferably has extremely high resolutions 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 display 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, further preferably 1000 ppi or higher, even more preferably 2000 ppi or higher, even more preferably 3000 ppi or higher, still more preferably 5000 ppi or higher, and even more preferably 7000 ppi or higher. By using the aforementioned display device with one or both of high resolution and high definition, realism and depth can be further enhanced in personal electronic devices for portable or home use. Furthermore, there is no particular limitation on the screen ratio (aspect ratio) of the display device according to one aspect of the present invention. For example, the display device can accommodate various screen ratios such as 1:1 (square), 4:3, 16:9, and 16:10.

[0723] 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).

[0724] 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; or reading programs or data stored in the storage medium; etc.

[0725] use Figures 28A-28D 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.

[0726] Figure 28A The electronic device 6700A shown and Figure 28BThe electronic devices 6700B shown include a pair of display panels 6751, a pair of frames 6721, a communication unit (not shown), a pair of mounting units 6723, a control unit (not shown), an imaging unit (not shown), a pair of optical components 6753, an eyeglass frame 6757, and a pair of nose pads 6758.

[0727] The display panel 6751 can be used with a display device according to one aspect of the present invention. Thus, a highly reliable electronic device can be realized.

[0728] Both electronic devices 6700A and 6700B can project images displayed on the display panel 6751 onto the display area 6756 in the optical component 6753. Because the optical component 6753 is transparent, the user can see the image displayed on the display area by overlapping the image seen through the optical component 6753. Therefore, both electronic devices 6700A and 6700B are capable of AR display.

[0729] Both electronic devices 6700A and 6700B can be equipped with cameras capable of capturing images from the front, serving as imaging units. Furthermore, by incorporating accelerometers such as gyroscopes into both electronic devices 6700A and 6700B, the orientation of the user's head can be detected, and the corresponding image can be displayed on the display area 6756.

[0730] The communications unit includes a wireless communication device through which video signals can be supplied, for example. Furthermore, in addition to or in addition to the wireless communication device, a connector capable of connecting cables supplying video signals and power potential may also be included.

[0731] In addition, electronic devices 6700A and 6700B are equipped with batteries that can be charged wirelessly or via wired means, or both.

[0732] The frame 6721 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 6721 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 perform processing such as temporarily pausing or replaying a moving image, while a swipe operation can perform processing such as fast forward or rewind. Furthermore, by providing a touch sensor module in each of the two frames 6721, the operating range can be expanded.

[0733] Various touch sensors can be used as touch sensor modules. For example, capacitive, resistive, infrared, electromagnetic induction, surface acoustic wave, and optical sensors can be employed. In particular, capacitive or optical sensors are preferred for use in touch sensor modules.

[0734] When using optical touch sensors, photoelectric conversion elements (also known as photoelectric conversion devices) can be used as the light-receiving element. The active layer of the photoelectric conversion element can use one or both of inorganic and organic semiconductors.

[0735] Figure 28C The electronic device 6800A shown and Figure 28D The electronic devices 6800B shown include a pair of display units 6820, a frame 6821, a communication unit 6822, a pair of mounting units 6823, a control unit 6824, a pair of imaging units 6825, and a pair of lenses 6832.

[0736] The display unit 6820 can be equipped with a display device according to one aspect of the present invention. This allows for the realization of a highly reliable electronic device.

[0737] The display unit 6820 is located inside the housing 6821 in a position visible through the lens 6832. Furthermore, by displaying different images on each of the pair of display units 6820, three-dimensional display utilizing parallax can be achieved.

[0738] Both electronic devices 6800A and 6800B can be referred to as VR-oriented electronic devices. Users wearing electronic devices 6800A or 6800B can see the image displayed on the display unit 6820 through the lens 6832.

[0739] Electronic devices 6800A and 6800B preferably have a mechanism in which the left and right positions of the lens 6832 and the display unit 6820 can be adjusted to position the lens 6832 and the display unit 6820 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 6832 and the display unit 6820.

[0740] Users can wear electronic devices 6800A or 6800B on their heads using the mounting unit 6823. For example, in Figure 28C In this case, the mounting part 6823 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 wear it, the mounting part 6823 can have a helmet-like or strap-like shape, for example.

[0741] The imaging unit 6825 has the function of acquiring external information. The data acquired by the imaging unit 6825 can be output to the display unit 6820. An image sensor can be used in the imaging unit 6825. Furthermore, multiple cameras can be provided to accommodate various viewing angles such as telephoto and wide-angle.

[0742] Note that the example shown here includes an imaging unit 6825, which can be a ranging sensor (also called a detection unit) capable of measuring the distance to an object. In other words, the imaging unit 6825 is one type of detection unit. For example, an image sensor or a distance image sensor such as a Light Detection and Ranging (LIDAR) sensor 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.

[0743] The electronic device 6800A may also include a vibration mechanism for use as bone conduction headphones. For example, the display unit 6820, the frame 6821, and the mounting unit 6823 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 wearing the electronic device 6800A.

[0744] Electronic devices 6800A and 6800B may also include input terminals. For example, cables supplying image signals from image output devices and power for charging batteries installed in the electronic devices can be connected to the input terminals.

[0745] An electronic device according to one aspect of the present invention may also have the function of wirelessly communicating with the headset 6750. The headset 6750 includes a communication unit (not shown) and has wireless communication functionality. The headset 6750 can receive information (e.g., voice data) from the electronic device via the wireless communication function. For example, Figure 28A The illustrated electronic device 6700A has the function of transmitting information to the headset 6750 via wireless communication. Furthermore, for example... Figure 28C The electronic device 6800A shown has the function of sending information to the headset 6750 via wireless communication.

[0746] In addition, electronic devices may also include an earphone unit. Figure 28B The illustrated electronic device 6700B includes an earphone unit 6727. For example, a structure can be adopted in which the earphone unit 6727 and the control unit are connected in a wired manner. A portion of the wiring connecting the earphone unit 6727 and the control unit can also be configured inside the housing 6721 or the mounting portion 6723.

[0747] same,Figure 28D The illustrated electronic device 6800B includes an earphone unit 6827. For example, a structure can be adopted in which the earphone unit 6827 and the control unit 6824 are connected by a wire. A portion of the wiring connecting the earphone unit 6827 and the control unit 6824 can also be disposed inside the housing 6821 or the mounting portion 6823. Furthermore, the earphone unit 6827 and the mounting portion 6823 can also include magnets. Thus, the earphone unit 6827 can be magnetically secured to the mounting portion 6823, making storage easy, which is therefore preferred.

[0748] Electronic devices may also include an audio output terminal capable of connecting to headphones or headsets. Furthermore, electronic devices may include one or both of an audio input terminal and an audio input mechanism. As an audio input mechanism, a microphone or similar recording device can be used. By incorporating an audio input mechanism into the electronic device, it can be made to function as a so-called headset.

[0749] Thus, as an embodiment of the present invention, both eyeglass type (electronic device 6700A and electronic device 6700B, etc.) and goggle type (electronic device 6800A and electronic device 6800B, etc.) are preferred electronic devices.

[0750] Furthermore, one aspect of the present invention allows the electronic device to transmit information to headphones in a wired or wireless manner.

[0751] Figure 29A The electronic device 6500 shown is a portable information terminal device that can be used as a smartphone.

[0752] 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.

[0753] The display unit 6502 can use a display device according to one aspect of the present invention. Therefore, a highly reliable electronic device can be realized.

[0754] Figure 29B It is a cross-sectional schematic diagram of one end of the microphone 6506, including the frame 6501.

[0755] 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.

[0756] 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).

[0757] In the area outside the display unit 6502, a portion of the display panel 6511 is folded back, and this folded area 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.

[0758] The display panel 6511 can be a flexible display 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 provide a connection to the FPC 6515 on the back of the pixel portion, a narrow-bezel electronic device can be realized.

[0759] Figure 29C An example of a television device is shown. In the television device 7100, a display unit 7000 is assembled in a frame 7101. Here is shown the structure in which the frame 7101 is supported by a bracket 7103.

[0760] The display unit 7000 can use a display device according to one aspect of the present invention. This allows for the realization of a highly reliable electronic device.

[0761] It can be operated using the operating switch on the housing 7101 and the separately provided remote control 7111. Figure 29C The operation of the television device 7100 shown is illustrated. Alternatively, a touch sensor may be included in the display unit 7000, allowing operation of the television device 7100 by touching the display unit 7000 with a finger or similar object. Furthermore, a display unit for displaying data output from the remote control 7111 may be included in the remote control 7111. Channel and volume adjustments can be made using the operation keys or touch panel of the remote control 7111, and the images displayed on the display unit 7000 can also be manipulated.

[0762] Furthermore, the television device 7100 includes a receiver and a modem. It can receive general television broadcasts using the receiver. Moreover, it can connect to a wired or wireless communication network via the modem, enabling one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers, etc.) information communication.

[0763] Figure 29DAn 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.

[0764] The display unit 7000 can use a display device according to one aspect of the present invention. This allows for the realization of a highly reliable electronic device.

[0765] Figure 29E and Figure 29F Here is an example of digital signage.

[0766] Figure 29E The digital sign 7300 shown includes a frame 7301, a display unit 7000, and a speaker 7303. It may also include LEDs, operation buttons (including a power switch or operation switch), connection terminals, various sensors, and a microphone.

[0767] Figure 29F 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.

[0768] exist Figure 29E and Figure 29F In this embodiment, a display 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.

[0769] 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.

[0770] By using a touch panel in the display unit 7000, not only can static or dynamic images be displayed on the display unit 7000, but users can also operate it intuitively, making it preferable. Furthermore, when used to provide information such as route information or traffic information, intuitive operation enhances ease of use.

[0771] like Figure 29E and Figure 29F 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.

[0772] 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). Thus, multiple users can participate in the game simultaneously and enjoy the experience.

[0773] Figures 30A-30G 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), and a microphone 9008, etc.

[0774] Figures 30A-30G The 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 a calendar, date, or time; controlling processing using various software (programs); wireless communication function; or 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 can be installed in the electronic device to enable it to have 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); and displaying the captured images on a display unit; etc.

[0775] The following is a detailed explanation. Figures 30A-30G The electronic device shown.

[0776] Figure 30A This is a perspective view showing a portable information terminal 9101. The portable information terminal 9101 can be used, for example, as a smartphone. Note that a speaker 9003, a connection terminal 9006, a sensor 9007, etc., may also be included in the portable information terminal 9101. Furthermore, as a portable information terminal 9101, text or image information can be displayed on multiple surfaces. Figure 30AThe image shows an example displaying three icons 9050. Additionally, 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, phone calls, etc.; 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, for example, at the location where information 9051 is displayed.

[0777] Figure 30B This is a perspective view showing a portable information terminal 9102. The portable information terminal 9102 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 9102 is placed in a jacket pocket, the user can check information 9053 displayed in a position visible from above the portable information terminal 9102. For example, the user can check this display without taking the portable information terminal 9102 out of their pocket, thereby enabling them to determine, for example, whether to answer a phone call.

[0778] Figure 30C This is a perspective view of a tablet terminal 9103. The tablet terminal 9103 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 9103 includes a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front of the frame 9000; operation keys 9005 serving as operating buttons on the left side of the frame 9000; and a connection terminal 9006 on the bottom surface.

[0779] Figure 30D 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). Furthermore, the display surface of the display unit 9001 is curved, allowing display along its curved surface. Additionally, the portable information terminal 9200 can perform hands-free calls, for example, by communicating with a headset capable of wireless communication. Furthermore, by utilizing the connection terminal 9006, the portable information terminal 9200 can transmit data or charge with other information terminals. Charging can also be performed wirelessly.

[0780] Figures 30E-30G This is a perspective view showing the foldable portable information terminal 9201. Furthermore, Figure 30E This is a 3D view of the portable information terminal 9201 in its unfolded state. Figure 30G It is a 3D image of the folded state. Figure 30F FromFigure 30E status and Figure 30G 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.

[0781] This embodiment can be appropriately combined with other embodiments. Furthermore, in this specification, where multiple structural examples are shown in one embodiment, these structural examples can be appropriately combined.

[0782] [Symbol Explanation]

[0783] ANO: Conductive film, C21: Capacitor, C22: Capacitor, CCA: Layer, CCB: Layer, CCR: Layer, CCG: Layer, CCX: Layer, CFA: Layer, CFB: Layer, CFC: Layer, CFX: Layer, CP: Conductive material, CUA: Conversion unit, CUB: Conversion unit, CUC: Conversion unit, CUX: Conversion unit, DMR: Layer, DMG: Layer, DMX1: Layer, DMX11: Layer, DMX12: Layer, DMX13: Layer, DMX2: Layer, DMX21: Layer, DMX22: Layer, DMX23: Layer, GD: Driving circuit, LA: Light, LB: Light, LL: Light, LSA: Light source, LSB: Light source, LSC: Light source, LSD: Light source, L SX: Light source, LX: Light, M21: Transistor, N21: Node, N22: Node, SD: Driver circuit, SW21: Switch, SW22: Switch, SW23: Switch, 14b: Substrate, 16b: Substrate, 17: Substrate, 18: Substrate, 37b: Display section, 61W: Light source, 63W: Light source, 71: Substrate, 73: Substrate, 80: Display area, 83B: Light, 83G: Light, 83R: Light, 100A: Display device, 100C: Display device, 100D: Display device, 100E: Display device, 100F: Display device, 100G: Display device, 100H: Display device, 100I: Display device, 100J: Display device, 100K: Display device 100L: Display device; 100M: Display device; 100: Display device; 103X: Unit; 104X: Layer; 105X: Layer; 106X: Intermediate layer; 107: Display section; 111X: Layer; 112X: Layer; 113X: Layer; 117: Light-shielding layer; 120: Substrate; 122: Adhesive layer; 140: Connector; 142: Adhesive layer; 153: Insulating layer; 156: Adhesive layer; 162: Insulating layer; 164: Circuit; 165: Wiring; 166: Conductive layer; 168: Conductive layer; 171: Conductive layer; 172W: EL layer; 173: Conductive layer; 174: Common layer; 176: IC; 177: FPC; 183B: Conversion unit; 183G: Conversion unit Unit, 183R: Conversion unit, 201: Transistor, 204: Connector, 205: Transistor, 209: Transistor, 210: Transistor, 211: Insulating layer, 213: Insulating layer, 214: Insulating layer, 215: Insulating layer, 218: Insulating layer, 221: Conductive layer, 222a: Conductive layer, 222b: Conductive layer, 223: Conductive layer, 225: Insulating layer, 231i: Channel forming region, 231n: Low resistance region, 231: Semiconductor layer, 240: Capacitor, 241: Conductive layer, 242: Connector layer, 243: Insulating layer, 245: Conductive layer, 251: Conductive layer, 252: Conductive layer, 254: Insulating layer, 255a: Insulating layer, 255b: Insulating layer255c: Insulating layer, 255: Insulating layer, 256: Plug, 261: Insulating layer, 262: Insulating layer, 263: Insulating layer, 264: Insulating layer, 265: Insulating layer, 270: Sacrificial layer, 271: Protective layer, 272: Insulating layer, 273: Protective layer, 274a: Conductive layer, 274b: Conductive layer, 274: Plug, 275: Plug, 278: Insulating layer, 280: Display module, 290: FPC, 301A: Substrate, 301B: Substrate, 301: Substrate, 310A: Transistor, 310B: Transistor, 310: Transistor, 311: Conductive layer, 312: Low resistance region, 313: Insulating layer, 314: Insulating layer, 315: Component separation layer, 32 0A: Transistor, 320B: Transistor, 320: Transistor, 321: Semiconductor layer, 323: Insulating layer, 324: Conductive layer, 325: Conductive layer, 326: Insulating layer, 327: Conductive layer, 328: Insulating layer, 329: Insulating layer, 331: Substrate, 332: Insulating layer, 335: Insulating layer, 336: Insulating layer, 341: Conductive layer, 342: Conductive layer, 343: Connector, 344: Insulating layer, 345: Insulating layer, 346: Insulating layer, 347: Bump, 348: Adhesive layer, 510: Substrate, 519B: Terminal, 520: Functional layer, 530A: Pixel circuit, 530B: Pixel circuit, 530C: Pixel circuit, 530D: Pixel circuit, 540: Functional layer, 550A: Light-emitting device, 550B: Light-emitting device, 550C: Light-emitting device, 550D: Light-emitting device, 550X: Light-emitting device, 551X: Electrode, 552X: Electrode, 591A: Opening, 591B: Opening, 700: Display device, 702A: Pixel, 702B: Pixel, 702C: Pixel, 702D: Pixel, 703: Pixel, 731: Area, 6500: Electronic device, 6501: Frame, 6502: Display unit, 6503: Power button, 6504: Button, 6505: Speaker, 6506: Microphone, 6507: Camera, 6508: Light source, 6510: Protective component, 6511: Display panel, 6512: Optical components, 6513: Touch sensor panel, 6515: FPC, 6516: IC, 6517: Printed circuit board, 6518: Battery, 6700A: Electronic device, 6700B: Electronic device, 6721: Frame, 6723: Mounting part, 6727: Earphone part, 6750: Earphone, 6751: Display panel, 6753: Optical component, 6756: Display area, 6757: Eyeglass frame, 6758: Nose pad, 6800A: Electronic device, 6800B: Electronic device, 6820: Display part, 6821: Frame, 6822: Communication part, 6823: Mounting part, 6824: Control part, 6825: Imaging part, 6827: Earphone part, 6832: Lens,7000: Display unit; 7100: Television unit; 7101: Cabinet; 7103: Stand; 7111: Remote control; 7200: Notebook computer; 7211: Cabinet; 7212: Keyboard; 7213: Pointing device; 7214: External connection port; 7300: Digital signage; 7301: Cabinet; 7303: Speaker; 7311: Information terminal equipment; 7400: Digital signage; 7401: Column; 7411: Information terminal equipment; 9000: Cabinet 9001: Display unit; 9002: Camera; 9003: Speaker; 9005: Operation keys; 9006: Connection terminal; 9007: Sensor; 9008: Microphone; 9050: Icon; 9051: Information; 9052: Information; 9053: Information; 9054: Information; 9055: Hinge; 9101: Portable information terminal; 9102: Portable information terminal; 9103: Tablet terminal; 9200: Portable information terminal; 9201: Portable information terminal.

Claims

1. A light-emitting device, comprising: First light source; as well as First conversion unit The first light source overlaps with the first conversion unit. The first light source illuminates the first conversion unit with first light. The first light has a spectrum with intensity in the region of a first wavelength. The first conversion unit includes a first layer and a second layer. The first layer is sandwiched between the second layer and the first light source. The first layer converts the first light into the second light. The second light has a spectrum with a peak at the second wavelength. The second wavelength is longer than the first wavelength. The second layer has a reflectivity of 0.8 or higher and 1.0 or lower for the first wavelength. Furthermore, the second layer has a transmittance of 0.8 or more and 1.0 or less for the second wavelength.

2. The light-emitting device according to claim 1, The first layer contains quantum dots.

3. The light-emitting device according to claim 1, The second layer includes the third, fourth, and fifth layers. The fourth layer is sandwiched between the third layer and the fifth layer. When the fourth layer is in a film state and has a refractive index of less than 1.6 for the first wavelength, Both the third and fifth layers, in their film state, have a refractive index of 1.6 or higher for the first wavelength. Furthermore, when the fourth layer is in a film state and has a refractive index of 1.6 or higher for the first wavelength, the third layer and the fifth layer, both in a film state, have a refractive index of less than 1.6 for the first wavelength.

4. The light-emitting device according to claim 1, The first conversion unit includes a sixth layer. The sixth layer is sandwiched between the first layer and the first light source. The sixth layer has a transmittance of 0.8 or higher and 1.0 or lower for the first wavelength. Furthermore, the sixth layer has a reflectivity of 0.8 or higher and 1.0 or lower for the second wavelength.

5. The light-emitting device according to claim 4, The sixth layer includes the seventh, eighth, and ninth layers. The eighth layer is sandwiched between the seventh layer and the ninth layer. When the eighth layer is in a film state and has a refractive index of less than 1.6 for the second wavelength, Both the seventh and ninth layers, in their film state, have a refractive index of 1.6 or higher for the second wavelength. Furthermore, when the eighth layer is in a film state and has a refractive index of 1.6 or higher for the second wavelength, the seventh layer and the ninth layer are both in a film state and have a refractive index of less than 1.6 for the second wavelength.

6. The light-emitting device according to claim 1, The first conversion unit includes a tenth layer. The second layer is sandwiched between the tenth layer and the first light source. The tenth layer has a transmittance greater than 0 and less than 0.2 for the first wavelength. Furthermore, the tenth layer has a transmittance of 0.6 or more and 1.0 or less for the second wavelength.

7. The light-emitting device according to claim 1, comprising: A set of pixels, The set of pixels includes a first pixel, a second pixel, and a third pixel. The first pixel includes a first light-emitting device and a first pixel circuit. The first light-emitting device is electrically connected to the first pixel circuit, and the second pixel includes a second light-emitting device and a second pixel circuit, with the second light-emitting device being electrically connected to the second pixel circuit. The third pixel includes a third light-emitting device and a third pixel circuit, and the third light-emitting device is electrically connected to the third pixel circuit. The first light-emitting device includes a second light source and a second conversion unit, wherein the second light source and the second conversion unit overlap. The second light source illuminates the second conversion unit with the first light. The first light has an emission spectrum that includes blue light. The second conversion unit includes an eleventh layer and a twelfth layer. The eleventh layer is sandwiched between the twelfth layer and the second light source, and the eleventh layer converts the first light into the third light. The third light has an emission spectrum that includes red light. The twelfth layer has a reflectivity of 0.8 or higher and 1.0 or lower for the first light, and a transmittance of 0.8 or higher and 1.0 or lower for the third light. The second light-emitting device includes a third light source and a third conversion unit, wherein the third light source and the third conversion unit overlap. The third light source illuminates the first light onto the third conversion unit, and the third conversion unit includes a thirteenth layer and a fourteenth layer. The thirteenth layer is sandwiched between the fourteenth layer and the third light source, and the thirteenth layer converts the first light into a fourth light. The fourth light has an emission spectrum that includes green light. The fourteenth layer has a reflectivity of 0.8 or higher and 1.0 or lower for the first light, and a transmittance of 0.8 or higher and 1.0 or lower for the fourth light. The third light-emitting device includes a fourth light source. Furthermore, the fourth light source emits the first light.

8. The light-emitting device according to claim 7, The eleventh layer contains quantum dots. Furthermore, the thirteenth layer contains quantum dots.

9. The display device according to claim 7, The second conversion unit includes a fifteenth layer. The fifteenth layer is sandwiched between the eleventh layer and the second light source. The fifteenth layer has a transmittance of 0.8 or more and 1.0 or less for the first light, and the fifteenth layer has a reflectance of 0.8 or more and 1.0 or less for red light.

10. The display device according to claim 7, The second conversion unit includes a sixteenth layer. The sixteenth layer has a transmittance of greater than 0 and less than 0.2 for the first light, and the sixteenth layer has a transmittance of greater than 0.6 and less than 1.0 for red light.

11. The display device according to claim 7, The third conversion unit includes a seventeenth layer. The seventeenth layer is sandwiched between the thirteenth layer and the third light source. The seventeenth layer has a transmittance of 0.8 or more and 1.0 or less for the first light, and the seventeenth layer has a reflectance of 0.8 or more and 1.0 or less for green light.

12. The display device according to claim 7, The third conversion unit includes an eighteenth layer. The eighteenth layer has a transmittance of greater than 0 and less than 0.2 for the first light, and the eighteenth layer has a transmittance of greater than 0.6 and less than 1.0 for green light.

13. The display device according to claim 7, The third light-emitting device includes a fourth conversion unit. The fourth light source overlaps with the fourth conversion unit. The fourth light source illuminates the fourth conversion unit with the first light. The first light has an emission spectrum that includes both blue and green light. The fourth conversion unit includes a nineteenth layer. The nineteenth layer has a transmittance of green light greater than 0 and less than 0.

2. Furthermore, the nineteenth layer has a transmittance of 0.6 or higher and 1.0 or lower for blue light.

14. The display device according to claim 7, The set of pixels includes the fourth pixel. The fourth pixel includes a fifth light source. And the fifth light source emits the first light.

15. A display module, comprising: The display device according to any one of claims 7 to 14; as well as At least one of a connector and an integrated circuit.

16. An electronic device comprising: The display device according to any one of claims 7 to 14; as well as At least one of a battery, camera, speaker, and microphone.

Images