Display device, display module, and electronic apparatus

Abstract

Provided is a display device having high display quality. Provided is a display device capable of performing desired display without performing conversion of image data. A display device according to one embodiment of the present invention includes a first pixel. The first pixel includes a first light emitting element, a color conversion layer, and a first storage circuit. The first light-emitting element emits blue light. The color conversion layer has a function of converting light emitted by the first light emitting element into light of a longer wavelength. A first image signal and a first correction signal are supplied to a first pixel. The first storage circuit has a function of holding the first correction signal and a function of adding the first correction signal to the first image signal. The first pixel has a function of displaying an image using the first image signal and the first correction signal.

Description

Technical Field

[0001] One embodiment of the present invention relates to a display device, a display module, and an electronic device.

[0002] In addition, one embodiment of the present invention is not limited to the above-mentioned technical field. Examples of technical fields of one embodiment of the present invention include semiconductor devices, display devices, light-emitting devices, power storage devices, storage devices, electronic devices, lighting devices, input devices (e.g., touch sensors, etc.), input / output devices (e.g., touch panels, etc.), driving methods of these devices, or manufacturing methods of these devices. Background Art

[0003] In recent years, there has been a demand for larger display devices. For example, the mainstream of home television devices is a TV device with a screen size of more than 50 inches diagonally. The larger the screen size, the more information can be displayed at one time, so there is a demand for further larger screens for digital signage and the like.

[0004] In addition, there is a demand for high-resolution display devices. For example, the development of display devices with a large number of pixels, such as full HD (1920×1080 pixels) display panels, 4K (3840×2160 or 4096×2160 pixels, etc.) display panels, and 8K (7680×4320 or 8192×4320 pixels, etc.) display panels, is booming.

[0005] Light-emitting elements (hereinafter referred to as "EL elements") that utilize the electroluminescence phenomenon are easy to achieve in terms of thinness and lightness, can respond to input signals at high speed, and can be driven using a DC low-voltage power supply, etc. Therefore, their application in display devices is being studied. For example, Patent Document 1 discloses a flexible light-emitting device that uses an organic EL element.

[0006] In addition, the use of quantum dots as color conversion (wavelength conversion) materials for EL elements is being studied. Quantum dots are semiconductor nanocrystals with a diameter of several nanometers and include 1×10 3 to 1×10 6 Atoms. Electrons, holes and excitons are enclosed in quantum dots, resulting in discrete energy states, and energy transfer depends on the size of the quantum dots. In other words, even quantum dots containing the same substance have different emission wavelengths depending on their size, so the emission wavelength can be easily adjusted by changing the size of the quantum dots used.

[0007] Silicon is mainly used as a semiconductor material for transistors constituting display devices, but in recent years, a technology for using transistors using metal oxides for pixels of display devices has also been developed. Patent Documents 2 and 3 disclose technologies for using metal oxides as semiconductor materials for transistors. [Prior technical literature] [Patent Document]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2014-197522 [Patent Document 2] Japanese Patent Application Publication No. 2007-123861 [Patent Document 3] Japanese Patent Application Publication No. 2007-96055 Summary of the invention Technical problem to be solved by the invention

[0009] In order to correctly display on the display device, the image data needs to correspond to the resolution of the display device. For example, when the resolution of the display device is 8K and the image data is data for 4K, full-screen display cannot be performed unless the amount of data is converted to 4 times. On the contrary, when the resolution of the display device is 4K and the image data is data for 8K, the amount of data needs to be converted to 1 / 4. In addition, the introduction of HDR (high dynamic range) display technology that improves image quality by adjusting brightness has been promoted. The conversion of the amount of data or the generation of image data processed by HDR requires a dedicated circuit, so the power consumption is high. It is preferable that the image data can be input to the pixels of the display device at least without converting the original image data.

[0010] One of the purposes of one embodiment of the present invention is to realize a large-scale display device. One of the purposes of one embodiment of the present invention is to provide a display device with high display quality. One of the purposes of one embodiment of the present invention is to provide a display device with high reliability. One of the purposes of one embodiment of the present invention is to provide a display device with low power consumption. One of the purposes of one embodiment of the present invention is to realize a thin or lightweight display device.

[0011] One of the purposes of one embodiment of the present invention is to provide a display device that can perform correct display without converting image data. In addition, one of the purposes of one embodiment of the present invention is to provide a display device capable of HDR display. One of the purposes of one embodiment of the present invention is to provide a display device capable of up-conversion. One of the purposes of one embodiment of the present invention is to provide a display device capable of increasing the brightness of a displayed image. One of the purposes of one embodiment of the present invention is to provide a display device capable of displaying two or more images in an overlapping manner. In addition, one of the purposes of one embodiment of the present invention is to provide a display device capable of applying a voltage higher than the output voltage of a driving circuit to a pixel.

[0012] Note that the description of the above-mentioned objects does not prevent the existence of other objects. One embodiment of the present invention does not necessarily need to achieve all of the above-mentioned objects. Objects other than the above-mentioned objects can be extracted from the description of the specification, drawings, and claims. Solutions to technical problems

[0013] A display device according to one embodiment of the present invention includes a first pixel. The first pixel includes a first light-emitting element, a color conversion layer, and a first storage circuit. The first light-emitting element emits blue light. The color conversion layer has a function of converting light emitted by the first light-emitting element into light of a longer wavelength. A first image signal and a first correction signal are supplied to the first pixel. The first storage circuit has a function of retaining the first correction signal and a function of adding the first correction signal to the first image signal. The first pixel has a function of displaying an image using the first image signal and the first correction signal.

[0014] The first light-emitting element preferably includes a stack of a first light-emitting unit and a second light-emitting unit, each of which emits blue light. Alternatively, the first light-emitting element preferably includes a stack of a first light-emitting unit, a second light-emitting unit, and a third light-emitting unit, each of which emits blue light. Each light-emitting unit preferably emits fluorescence.

[0015] The color conversion layer preferably comprises quantum dots.

[0016] The first pixel preferably further includes a transistor including a metal oxide in a channel formation region.

[0017] The display device preferably also includes a second pixel. The second pixel includes a second light-emitting element and a second storage circuit. The second light-emitting element presents blue light. A second image signal and a second correction signal are supplied to the second pixel. The second storage circuit has a function of holding the second correction signal and a function of adding the second correction signal to the second image signal. The second pixel has a function of displaying an image using the second image signal and the second correction signal. The first pixel is a pixel presenting a color different from that of the second pixel. The second pixel is a pixel presenting blue light.

[0018] The second light-emitting element preferably includes a stack of a first light-emitting unit and a second light-emitting unit, each of which emits blue light. Alternatively, the second light-emitting element preferably includes a stack of a first light-emitting unit, a second light-emitting unit, and a third light-emitting unit, each of which emits blue light.

[0019] The first pixel is preferably also supplied with a third correction signal. In this case, the first storage circuit has a function of retaining the third correction signal and a function of adding the third correction signal to the first image signal. The first pixel has a function of displaying an image using the first image signal, the first correction signal, and the third correction signal.

[0020] A display device according to one embodiment of the present invention includes a first pixel. The first pixel includes a first light-emitting element, a color conversion layer, and a first storage circuit. The first light-emitting element presents blue light. The first light-emitting element includes a stack of a first light-emitting unit presenting blue light, a second light-emitting unit presenting blue light, and a third light-emitting unit presenting blue light. The color conversion layer has a function of converting light emitted by the first light-emitting element into light of a longer wavelength. A first image signal, a first correction signal, and a second correction signal are supplied to the first pixel. The first storage circuit has a function of maintaining the first correction signal, a function of adding the first correction signal to the first image signal, a function of maintaining the second correction signal, and a function of adding the second correction signal to the first image signal. The first pixel has a function of displaying an image using the first image signal, the first correction signal, and the second correction signal. Each light-emitting unit preferably emits fluorescence.

[0021] The display device preferably also includes a second pixel. The second pixel includes a second light-emitting element and a second storage circuit. The second light-emitting element presents blue light. The first light-emitting element includes a stack of a first light-emitting unit presenting blue light, a second light-emitting unit presenting blue light, and a third light-emitting unit presenting blue light. The second pixel is supplied with a second image signal, a third correction signal, and a fourth correction signal. The second storage circuit has a function of maintaining the third correction signal, a function of adding the third correction signal to the second image signal, a function of maintaining the fourth correction signal, and a function of adding the fourth correction signal to the second image signal. The second pixel has a function of displaying an image using the second image signal, the third correction signal, and the fourth correction signal. The first pixel is a pixel presenting a color different from that of the second pixel, and the second pixel is a pixel presenting blue light.

[0022] One embodiment of the present invention is a module including a display device having any of the above-mentioned structures, which module is equipped with a connector such as a flexible printed circuit (Flexible printed circuit, hereinafter referred to as FPC) or TCP (Tape Carrier Package) or an integrated circuit (IC) is installed using a COG (Chip On Glass) method or a COF (Chip On Film) method.

[0023] One embodiment of the present invention is an electronic device including at least one of the above-mentioned module, an antenna, a battery, a housing, a camera, a speaker, a microphone, and an operation button. Effects of the Invention

[0024] According to one embodiment of the present invention, a display device can be enlarged. According to one embodiment of the present invention, a display device with high display quality can be provided. According to one embodiment of the present invention, a display device with high reliability can be provided. According to one embodiment of the present invention, a display device with low power consumption can be provided. According to one embodiment of the present invention, a display device can be made thinner or lighter.

[0025] According to one embodiment of the present invention, a display device that can correctly display without converting image data can be provided. According to one embodiment of the present invention, a display device capable of HDR display can be provided. According to one embodiment of the present invention, a display device capable of up-conversion can be provided. According to one embodiment of the present invention, a display device capable of increasing the brightness of a displayed image can be provided. According to one embodiment of the present invention, a display device capable of displaying two or more images in an overlapping manner can be provided. According to one embodiment of the present invention, a display device capable of applying a voltage higher than the output voltage of a driving circuit to a pixel can be provided.

[0026] Note that the description of the above effects does not prevent the existence of other effects. One embodiment of the present invention does not necessarily have all of the above effects. Effects other than the above effects can be extracted from the description of the specification, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] [Figure 1] Figure 1A and Figure 1B is a block diagram showing an example of a pixel. [Figure 2] Figure 2A and Figure 2B is a cross-sectional view showing an example of a pixel. [Figure 3] FIG. 3A to FIG. 3C is a cross-sectional view showing an example of a pixel. [Figure 4] FIG. 4A to FIG. 4D is a cross-sectional view showing an example of a light emitting element. [Figure 5] Figure 5A is a plan view showing an example of a display device. Figure 5B is a cross-sectional view showing an example of a display device. [ Figure 6 ] Figure 6 is a cross-sectional view showing an example of a display device. [ Figure 7 ] Figure 7 is a cross-sectional view showing an example of a display device. [ Figure 8 ] Figure 8 is a cross-sectional view showing an example of a display device. [Figure 9] Fig. 9A and Fig. 9B is a cross-sectional view showing an example of a transistor. [Figure 10] Fig. 10A is a block diagram showing an example of a pixel. Fig. 10B is a circuit diagram showing an example of a pixel. [Figure 11] Fig.11A and Fig. 11B is a timing chart showing an operation example of a pixel. [Figure 12] Fig. 12A and Fig. 12B is a circuit diagram showing an example of a pixel. [Figure 13] FIG. 13A to FIG. 13C is a timing chart showing an operation example of a pixel. [Figure 14] FIG. 14A to FIG. 14C is a timing chart showing an operation example of a pixel. [Figure 15] FIG. 15A to FIG. 15C is a circuit diagram showing an example of a circuit block. [Figure 16] Fig.16A and Fig. 16B It is a diagram showing correction of image data and synthesis of images. [Figure 17] 17A to 17D is a diagram showing an example of an electronic device. [Figure 18] FIG. 18A to FIG. 18F is a diagram showing an example of an electronic device. Modes for Carrying Out the Invention

[0028] The embodiments are described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the following description, and a person skilled in the art can easily understand that the mode and details can be transformed into various forms without departing from the purpose and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the contents described in the embodiments shown below.

[0029] Note that in the inventive structure described below, the same reference numerals are used in common in different drawings to show the same parts or parts with the same function, and repeated descriptions are omitted. In addition, when showing parts with the same function, the same hatching is sometimes used without adding a reference numeral in particular.

[0030] In addition, for ease of understanding, the positions, sizes, and ranges of various components shown in the drawings may not represent their actual positions, sizes, and ranges. Therefore, the disclosed invention is not necessarily limited to the positions, sizes, and ranges disclosed in the drawings.

[0031] In addition, depending on the situation or state, the "film" and the "layer" may be interchanged. For example, the "conductive layer" may be replaced with the "conductive film". Also, the "insulating film" may be replaced with the "insulating layer".

[0032] (Implementation Method 1) In this embodiment, a display device according to one embodiment of the present invention is described with reference to Figures 1A to 9B Provide explanation.

[0033] A display device according to one embodiment of the present invention includes a first pixel and a second pixel. The first pixel includes a first light-emitting element, a color conversion layer, and a first storage circuit. The second pixel includes a second light-emitting element and a second storage circuit.

[0034] The second pixel is a pixel that emits blue light. The second light emitting element emits blue light.

[0035] The first pixel is a pixel that presents a different color from the second pixel. For example, the first pixel is a pixel that presents red light, green light, or white light. The first light-emitting element presents blue light. The color conversion layer has a function of converting the light emitted by the first light-emitting element into light of a longer wavelength.

[0036] The light-emitting elements included in each pixel emit blue light, so compared with the case of manufacturing a light-emitting element that emits white light, the number of layers or types of materials for forming the film can be reduced, and the manufacturing device and manufacturing process can be simplified. In addition, because each pixel includes a light-emitting element of the same structure, compared with the case of forming multiple light-emitting elements separately (forming light-emitting elements that emit red light, green light, and blue light separately), high alignment accuracy of the metal mask and suppression of bending are not required. Therefore, it is easy to apply this pixel structure to large display devices.

[0037] In addition, when an organic EL element is used as a light-emitting element, it is easy to achieve a thinner and lighter display device, so it is preferred. In particular, by using an organic EL element with a series structure in which a plurality of light-emitting units are stacked, the life of the light-emitting element can be extended, and a display device with high reliability can be provided. For example, the light-emitting element preferably includes two or three light-emitting units that each emit blue light.

[0038] In addition, it is preferable to use quantum dots (QD) as the color conversion layer. The peak width of the emission spectrum of quantum dots is narrow, so light with high color purity can be obtained. Therefore, the display quality of the display device can be improved.

[0039] The first pixel is supplied with a first image signal and a first correction signal. The first storage circuit has a function of retaining the first correction signal and a function of adding the first correction signal to the first image signal. The first pixel has a function of displaying an image using the first image signal and the first correction signal.

[0040] The second pixel is supplied with the second image signal and the second correction signal. The second storage circuit has the function of retaining the second correction signal and the function of adding the second correction signal to the second image signal. The second pixel has the function of displaying an image using the second image signal and the second correction signal.

[0041] In a display device of one embodiment of the present invention, in addition to an image signal corresponding to image data, a signal (correction signal) corresponding to the correction data can also be supplied to the pixel. Thus, even if unconverted image data is supplied to the pixel, the desired display can be performed, thereby enabling reduction of the dedicated circuit required for the conversion of the image data or low power consumption. By supplying the correction signal to the pixel, for example, HDR display, up-conversion operation, and improvement of the brightness of the displayed image can be performed. In addition, by setting the correction signal to an image signal different from the image signal, two or more images can be displayed overlappingly.

[0042] Note that the correction signal supplied to one pixel may be one or more (eg, two).

[0043] In addition, when the transistor included in the pixel contains a metal oxide in the channel formation region, the off-state current is extremely low and the correction signal can be held for a long time, which is preferable.

[0044] [Pixels] Figure 1A and Figure 1B A block diagram showing pixels included in a display device according to one embodiment of the present invention.

[0045] like Figure 1A As shown, a pixel included in a display device according to one embodiment of the present invention includes a switching transistor (Switching Tr), a driving transistor (Driving Tr), a light emitting element (Light emitting element) and a memory (Memory).

[0046] The memory is supplied with data DATA_W. When the pixel is supplied with data DATA_W in addition to the image data DATA, the current flowing through the light emitting element increases, and thus the display device can express high brightness.

[0047] By supplying data DATA_W to pixels, in a display device according to one embodiment of the present invention, for example, image up-conversion, HDR display for correcting a portion or the entire image in a display area, or image correction such as brightness improvement of a displayed image can be performed. In addition, a plurality of images can be displayed in an overlapping manner or a voltage higher than the output voltage of a driving circuit can be supplied to a pixel.

[0048] Note that a pixel may include a plurality of memories. Thus, a plurality of data other than the image data DATA may be supplied to the pixel. Therefore, a plurality of processes such as the above-mentioned image correction process or the process of overlapping and displaying a plurality of images may be performed and the processes may be performed with high precision.

[0049] Figure 1B An example of a pixel including two memories is shown. Memory Memory_A is supplied with data DATA_W1, and memory Memory_B is supplied with data DATA_W2. For example, one memory may be used to perform image correction of image data DATA, and another memory may be used to superimpose other images on the image data DATA.

[0050] An example of the structure of the pixel circuit will be described in detail in Embodiment 2.

[0051] Figure 2A and Figure 2B A cross-sectional view showing a pixel of a display device according to one embodiment of the present invention.

[0052] Figure 2AThe display device shown has a top emission (top emission) structure. Figure 2B The display device shown has a bottom emission (bottom emission) structure.

[0053] exist Figure 2A and Figure 2B In the example, a display device that uses three color pixels of R (red), G (green), and B (blue) to present one color is described. Specifically, in Figure 2A and Figure 2B Pixel 1100R presenting red light, pixel 1100G presenting green light, and pixel 1100B presenting blue light are shown in FIG. Note that in a display device of one embodiment of the present invention, color elements are not limited, and colors other than RGB (for example, white, yellow, cyan, and magenta, etc.) may also be used.

[0054] In this specification, a pixel refers to a unit that can control brightness, for example. Therefore, as an example, a pixel refers to a color unit, and brightness is displayed using the color unit. Therefore, in the case of a color display device composed of color units such as R (red), G (green), and B (blue), the minimum unit of the image is set to a pixel composed of three pixels: a pixel of R, a pixel of G, and a pixel of B. At this time, each pixel of RGB can also be called a sub-pixel, and the three sub-pixels of RGB can be collectively referred to as a pixel.

[0055] The pixels 1100R, 1100G, and 1100B each include a light-emitting element 1105B that emits blue light.

[0056] The pixel 1100R further includes a color conversion layer 1104R. The color conversion layer 1104R can convert blue light into red light.

[0057] In the pixel 1100R, blue light emitted from the light emitting element 1105B is converted into red light by the color conversion layer 1104R, and thus red light 1106R is extracted to the outside.

[0058] The pixel 1100G further includes a color conversion layer 1104G. The color conversion layer 1104G can convert blue light into green light.

[0059] In the pixel 1100G, the wavelength of blue light emitted from the light emitting element 1105B is converted into green light by the color conversion layer 1104G, and thus green light 1106G is extracted to the outside.

[0060] The pixel 1100B is not provided with a color conversion layer, and thus blue light 1106B emitted from the light emitting element 1105B is extracted to the outside.

[0061] Examples of the color conversion layer include fluorescent materials and quantum dots.

[0062] Quantum dots are preferably used as the color conversion layer. By using quantum dots, the color conversion layer can emit light with a narrow half-width and bright colors. In addition, the color reproducibility of the display device can be improved.

[0063] The color conversion layer is formed by a droplet discharge method (eg, inkjet method), coating method, imprint method, various printing methods (screen printing method, offset printing method), etc. Alternatively, a color conversion film such as a quantum dot film may be used.

[0064] There are no particular restrictions on the materials that constitute quantum dots, and examples include Group 14 elements, Group 15 elements, Group 16 elements, compounds containing multiple Group 14 elements, compounds of Group 4 to Group 14 elements and Group 16 elements, compounds of Group 2 elements and Group 16 elements, compounds of Group 13 elements and Group 15 elements, compounds of Group 13 elements and Group 17 elements, compounds of Group 14 elements and Group 15 elements, compounds of Group 11 elements and Group 17 elements, iron oxides, titanium oxides, chalcogenides, semiconductor clusters, and the like.

[0065] Specifically, cadmium selenide, cadmium sulfide, cadmium telluride, zinc selenide, zinc oxide, zinc sulfide, zinc telluride, mercury sulfide, mercury selenide, mercury telluride, indium arsenide, indium phosphide, gallium arsenide, gallium phosphide, indium nitride, gallium nitride, indium antimonide, gallium antimonide, aluminum phosphide, aluminum arsenide, aluminum antimonide, lead selenide, lead telluride, lead sulfide, indium selenide, indium telluride, indium sulfide, gallium selenide, arsenic sulfide, arsenic selenide, arsenic telluride, antimony sulfide, antimony selenide, antimony telluride, bismuth sulfide, bismuth selenide, bismuth telluride, silicon, silicon carbide, germanium, tin, selenium, tellurium, boron, carbon, phosphorus, boron nitride, boron phosphide, boron arsenide, aluminum nitride, aluminum sulfide, barium sulfide, barium selenide, barium telluride, calcium sulfide, selenium Calcium fluoride, calcium telluride, beryllium sulfide, beryllium selenide, beryllium telluride, magnesium sulfide, magnesium selenide, germanium sulfide, germanium selenide, germanium telluride, tin sulfide, tin selenide, tin telluride, lead oxide, copper fluoride, copper chloride, copper bromide, copper iodide, copper oxide, copper selenide, nickel oxide, cobalt oxide, cobalt sulfide, iron oxide, iron sulfide, manganese oxide, molybdenum sulfide, vanadium oxide, tungsten oxide, tantalum oxide, titanium oxide, zirconium oxide, silicon nitride, germanium nitride, aluminum oxide, barium titanate, selenium zinc cadmium compound, indium arsenic phosphorus compound, cadmium selenium sulfur compound, cadmium selenium tellurium compound, indium gallium arsenic compound, indium gallium selenide compound, indium selenium sulfur compound, copper indium sulfur compound, and combinations thereof. In addition, so-called alloy-type quantum dots whose composition is expressed in an arbitrary ratio may also be used.

[0066] As the structure of quantum dots, there are core type, core shell type, core multishell type, etc. In addition, in quantum dots, since the proportion of surface atoms is high, the reactivity is high and condensation is easy to occur. Therefore, the surface of the quantum dots is preferably attached with a protective agent or provided with a protective group. By attaching a protective agent or providing a protective group, condensation can be prevented and the solubility in the solvent can be improved. In addition, electrical stability can also be improved by reducing reactivity.

[0067] The smaller the size of the quantum dot, the larger the band gap, so the size is appropriately adjusted to obtain the desired wavelength of light. As the crystal size becomes smaller, the luminescence of the quantum dot migrates to the blue side (that is, to the high energy side), so by changing the size of the quantum dot, the luminescence wavelength can be adjusted in the wavelength region of the spectrum covering the ultraviolet region, the visible light region and the infrared region. The size (diameter) of the commonly used quantum dots is, for example, more than 0.5nm and less than 20nm, preferably more than 1nm and less than 10nm. The smaller the size distribution of the quantum dot, the narrower the emission spectrum, so luminescence with high color purity can be obtained. In addition, there is no particular restriction on the shape of the quantum dot, which can be spherical, rod-shaped, disc-shaped, or other shapes. The quantum dot that is a rod-shaped quantum dot has the function of presenting directional light.

[0068] The light-emitting element 1105B includes a first electrode 1101 , an EL layer 1103B that emits blue light, and a second electrode 1102 .

[0069] One of the first electrode 1101 and the second electrode 1102 is used as an anode, and the other is used as a cathode. In this embodiment, the first electrode 1101 is used as an anode, and the second electrode 1102 is used as a cathode.

[0070] When a voltage higher than the threshold voltage of the light-emitting element is applied between the first electrode 1101 and the second electrode 1102, holes are injected into the EL layer 1103B from the anode (first electrode 1101) side, and electrons are injected into the EL layer 1103B from the cathode (second electrode 1102) side. The injected electrons and holes recombine in the EL layer 1103B, whereby a light-emitting substance included in the EL layer 1103B emits light.

[0071] Note that although Figure 2A and Figure 2B Although not shown in the figure, the light-emitting element 1105B is electrically connected to a transistor for controlling light emission.

[0072] The EL layer 1103B includes at least a light-emitting layer of a light-emitting substance that emits blue light.

[0073] The light-emitting substance is not particularly limited, and substances that emit fluorescence (fluorescent materials), substances that emit phosphorescence (phosphorescent materials), substances that exhibit thermally activated delayed fluorescence (TADF materials), and inorganic compounds (quantum dot materials, etc.) can be used.

[0074] The EL layer 1103B further includes functional layers such as a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. In addition, when a plurality of EL layers are stacked, a charge generation layer is included between the EL layers. The EL layer 1103B may be made of a low molecular weight compound or a high molecular weight compound, and may also contain an inorganic compound.

[0075] The EL layer 1103B may include a plurality of light-emitting units. Each light-emitting unit includes at least a light-emitting layer containing a light-emitting substance that emits blue light. Each light-emitting unit also includes functional layers such as a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. A charge generation layer is sandwiched between two light-emitting units.

[0076] The display device of one embodiment of the present invention is not limited to a structure in which three color pixels are used to present one color. For example, the display device may adopt a structure in which four color pixels of R (red), G (green), B (blue), and W (white) are used to present one color. Specifically, Figure 3A A pixel 1100R emitting red light, a pixel 1100G emitting green light, a pixel 1100B emitting blue light, and a pixel 1100W emitting white light are shown.

[0077] like Figure 3A The pixel 1100W that emits white light includes a light-emitting element 1105B that emits blue light and a color conversion layer 1104W. The color conversion layer 1104W can convert the blue light into white light.

[0078] In the pixel 1100W, blue light emitted from the light emitting element 1105B is converted into white light by the color conversion layer 1104W, and thus white light 1106W is extracted to the outside.

[0079] like Figure 3B and Figure 3C As shown in the figure, in order to enhance only blue light, a reflective electrode (reflective electrode) can be used as the first electrode 1101 and a semi-transmissive-semi-reflective electrode can be used as the second electrode 1102, and an optical microcavity resonator (microcavity structure) structure can be adopted. By adopting the microcavity structure, light obtained from the light-emitting layer in the EL layer 1103B can be resonated between the two electrodes, and the light emitted through the second electrode 1102 can be enhanced.

[0080] exist Figure 3B and Figure 3C In the embodiment, an optical adjustment layer 1107 is provided between the first electrode 1101 and the second electrode 1102 .

[0081] Figure 3B An example is shown in which a microcavity structure is used for pixels that emit light of each color. Figure 3C An example is shown in which a microcavity structure is used only for the pixel 1100B that emits blue light.

[0082] A light-transmitting conductive film (transparent conductive film) is used as the optical adjustment layer 1107, and optical adjustment can be performed by controlling the film thickness of the transparent conductive film. Note that the optical adjustment layer 1107 can also be regarded as an electrode of the light-emitting element. For example, a stacked structure of a reflective electrode and an optical adjustment layer can be used for the first electrode 1101.

[0083] Alternatively, the optical distance between the first electrode 1101 and the second electrode 1102 can be adjusted using one or more functional layers included in the EL layer 1103B.

[0084] Specifically, it is preferably adjusted so that the inter-electrode distance between the first electrode 1101 and the second electrode 1102 is approximately mλ / 2 (note that m is a natural number) when the wavelength of light obtained from the light-emitting layer is λ.

[0085] In order to amplify the desired light (wavelength: λ) obtained from the light-emitting layer, it is preferably adjusted as follows: the optical distance from the first electrode 1101 to the region (light-emitting region) in the light-emitting layer where the desired light can be obtained and the optical distance from the second electrode 1102 to the region (light-emitting region) in the light-emitting layer where the desired light can be obtained are both about (2m'+1)λ / 4 (note that m' is a natural number). Note that the "light-emitting region" described here refers to the recombination region of holes and electrons in the light-emitting layer.

[0086] By performing the above optical adjustment, the spectrum of specific monochromatic light (in this embodiment, blue light) obtainable from the light-emitting layer can be narrowed, thereby obtaining light emission with high color purity.

[0087] In addition, in the above case, strictly speaking, the optical distance between the first electrode 1101 and the second electrode 1102 can be said to be the total thickness from the reflective region in the first electrode 1101 to the reflective region in the second electrode 1102. However, since it is difficult to accurately determine the positions of the reflective regions in the first electrode 1101 and the second electrode 1102, it is assumed that the above effect can be fully obtained even if any position in the first electrode 1101 and the second electrode 1102 is set as the reflective region. In addition, strictly speaking, the optical distance between the first electrode 1101 and the light-emitting layer that can obtain the desired light can be said to be the optical distance between the reflective region in the first electrode 1101 and the light-emitting region in the light-emitting layer that can obtain the desired light. However, since it is difficult to accurately determine the positions of the reflective region in the first electrode 1101 and the light-emitting region in the light-emitting layer that can obtain the desired light, it is assumed that the above effect can be fully obtained even if any position in the first electrode 1101 is set as the reflective region and any position in the light-emitting layer that can obtain the desired light is set as the light-emitting region.

[0088] By adopting a microcavity structure, the luminous intensity of blue light in the front direction can be enhanced, thereby achieving low power consumption.

[0089] One or both of the first electrode 1101 and the second electrode 1102 is a light-transmitting electrode (transparent electrode, semi-transmissive-semi-reflective electrode, etc.). The other of the first electrode 1101 and the second electrode 1102 is preferably a reflective electrode. The visible light transmittance of the transparent electrode is 40% or more. In addition, the visible light reflectance of the semi-transmissive-semi-reflective electrode is 20% or more and 80% or less, preferably 40% or more and 70% or less. The visible light reflectance of the reflective electrode is 40% or more and 100% or less, preferably 70% or more and 100% or less.

[0090] [Light-emitting element] Figure 4A A specific example of a light-emitting element having a single structure is shown.

[0091] Figure 4A The light-emitting element shown includes an EL layer 1103B between a first electrode 1101 and a second electrode 1102. In the EL layer 1103B, a hole injection layer 1111, a hole transport layer 1112, a light-emitting layer 1113, an electron transport layer 1114, and an electron injection layer 1115 are stacked in this order from the first electrode 1101. The EL layer 1103B emits blue light.

[0092] FIG. 4B to FIG. 4D A specific example of a light-emitting element having a tandem structure is shown. FIG. 4B to FIG. 4DThe light-emitting element shown includes a plurality of light-emitting units between a first electrode 1101 and a second electrode 1102. A charge generation layer 1109 is preferably provided between two light-emitting units. Each light-emitting unit emits blue light. Note that the plurality of light-emitting units may have the same light-emitting substance or different light-emitting substances.

[0093] For example, Figure 4B The EL layer 1103B shown includes a charge generation layer 1109 between the light emitting unit 1123B(1) and the light emitting unit 1123B(2).

[0094] The charge generation layer 1109 has a function of injecting electrons into one of the light-emitting unit 1123B(1) and the light-emitting unit 1123B(2) and injecting holes into the other when a voltage is applied to the first electrode 1101 and the second electrode 1102. Figure 4B When a voltage higher than the potential of the second electrode 1102 is applied to the first electrode 1101 , electrons are injected from the charge generation layer 1109 into the light-emitting unit 1123B( 1 ) and holes are injected into the light-emitting unit 1123B( 2 ).

[0095] In view of light extraction efficiency, the charge generation layer 1109 preferably transmits visible light (specifically, the visible light transmittance of the charge generation layer 1109 is 40% or more). The charge generation layer 1109 can function even if its electrical conductivity is lower than that of the first electrode 1101 or the second electrode 1102.

[0096] Figure 4C The EL layer 1103B shown includes the charge generation layer 1109 between the first light-emitting unit 1123B(1) and the second light-emitting unit 1123B(2), and includes the charge generation layer 1109 between the second light-emitting unit 1123B(2) and the third EL layer 1103B(3). Figure 4D The light-emitting element shown has n EL layers (n is a natural number equal to or greater than 2), and a charge generation layer 1109 is provided between the EL layers.

[0097] The behavior of electrons and holes in the charge generation layer 1109 provided between the light-emitting unit 1123B(m) and the light-emitting unit 1123B(m+1) is described. When a voltage higher than the threshold voltage of the light-emitting element is applied between the first electrode 1101 and the second electrode 1102, holes and electrons are generated in the charge generation layer 1109, the holes move to the light-emitting unit 1123B(m+1) provided on the second electrode 1102 side, and the electrons move to the light-emitting unit 1123B(m) provided on the first electrode 1101 side. The holes injected into the light-emitting unit 1123B(m+1) and the electrons injected from the second electrode 1102 side recombine, and the light-emitting substance contained in the light-emitting unit 1123B(m+1) emits light. In addition, the electrons injected into the light-emitting unit 1123B(m) and the holes injected from the first electrode 1101 side recombine, and the light-emitting substance contained in the light-emitting unit 1123B(m) emits light. Therefore, holes and electrons generated in the charge generation layer 1109 each emit light in a different light-emitting unit.

[0098] Note that when the light-emitting units are arranged in contact with each other and the same structure as the charge generation layer is formed between the light-emitting units, the light-emitting units may be arranged in contact with each other without sandwiching the charge generation layer. For example, when a charge generation region is formed on one surface of the light-emitting unit, the light-emitting unit may be arranged in contact with the surface.

[0099] Compared with a single-structure light-emitting element, a tandem-structured light-emitting element has a high current efficiency and can emit light of the same brightness with less current. Therefore, the life of the light-emitting element is long and the reliability of the display device can be improved.

[0100] There is no particular restriction on the luminescent material of each luminescent unit. In order to improve reliability, it is preferred to stack a plurality of fluorescent luminescent units. Alternatively, one or more fluorescent luminescent units and one or more phosphorescent luminescent units may be stacked.

[0101] [Display device] use FIG. 5A to FIG. 8 A specific example of a display device according to one embodiment of the present invention will be described.

[0102] Figure 5A A top view of the display device 10A is shown. Figure 5B Shown along Figure 5A A cross-sectional view along the dashed line A1-A2 is shown.

[0103] Figure 5A The display device 10A shown includes a display unit 71 and a drive circuit 78. An FPC 74 is connected to the display device 10A.

[0104] The display device 10A is a display device of a top emission structure.

[0105] like Figure 5B As shown, the display device 10A includes a substrate 361, an insulating layer 367, transistors 301, 303, wiring 307, an insulating layer 314, a light-emitting element 110B, an insulating layer 104, a protective layer 117, a partition wall 107, a color conversion layer CCMR, a color conversion layer CCMG, an adhesive layer 318 and a substrate 371, etc.

[0106] The light-emitting element 110B emits blue light. The light-emitting element 110B includes a pixel electrode 111, an EL layer 113, and a common electrode 115. The pixel electrode 111 is electrically connected to the source or drain of the transistor 303. These components may be directly connected or connected to each other through other conductive layers. The EL layer 113 and the common electrode 115 are continuously provided in a plurality of light-emitting elements.

[0107] The light emitting element 110B is covered with a protective layer 117 .

[0108] In the pixel emitting red light, the light emitting element 110B overlaps the color conversion layer CCMR via the protective layer 117. The blue light emitted from the light emitting element 110B is converted into red light by the color conversion layer CCMR, so that the red light 106R is extracted to the outside.

[0109] In the pixel emitting green light, the light emitting element 110B overlaps the color conversion layer CCMG via the protective layer 117. The blue light emitted from the light emitting element 110B is converted into green light by the color conversion layer CCMG, so that the green light 106G is extracted to the outside.

[0110] Since the color conversion layer is not provided in the pixel emitting blue light, the blue light 106B emitted from the light emitting element 110B is extracted to the outside via the protective layer 117 .

[0111] For example, the color conversion layers CCMR and CCMG may be formed by an inkjet method after forming the partition wall 107. This makes it possible to easily form the color conversion layer in a desired region.

[0112] The insulating layer 104 covers the end of the pixel electrode 111. The insulating layer 104 electrically insulates two adjacent pixel electrodes 111.

[0113] The protective layer 117 is provided on the light-emitting element 110B and covers the end of the common electrode 115, and is in contact with the insulating layer 104 and the insulating layer 313 on the outside of the end of the common electrode 115. Thus, it is possible to suppress the intrusion of impurities into the transistor and the light-emitting element. In particular, it is preferred to use an inorganic film (or inorganic insulating film) with high barrier properties as the protective layer 117 and the insulating layer 313. Moreover, it is preferred that an inorganic insulating film with high barrier properties is also used for the insulating layer 104. At the end of the display device and its vicinity, by stacking a plurality of inorganic films (or inorganic insulating films) in contact, impurities are not easily intruded from the outside, and thus the degradation of the transistor and the light-emitting element can be suppressed.

[0114] The substrate 361 and the substrate 371 are bonded together by the adhesive layer 318. The space 121 sealed by the substrate 361, the substrate 371, and the adhesive layer 318 is preferably filled with an inert gas such as nitrogen or argon, or a resin.

[0115] The substrate 361 and the substrate 371 can be made of a material such as glass, quartz, resin, metal, alloy, or semiconductor. The substrate 371 on the side where light is extracted from the light-emitting element is made of a material that transmits the light. As the substrate 361 and the substrate 371, a flexible substrate is preferably used.

[0116] As the adhesive layer, various curing adhesives such as light curing adhesives such as ultraviolet curing adhesives, reaction curing adhesives, heat curing adhesives, and anaerobic adhesives can be used. In addition, an adhesive sheet or the like can also be used.

[0117] The driving circuit 78 includes a transistor 301 . The display portion 71 includes a transistor 303 .

[0118] Each transistor includes a gate, a gate insulating layer 311, a semiconductor layer, a back gate, a source and a drain. The gate (the lower gate) overlaps with the semiconductor layer via the gate insulating layer 311. The back gate (the upper gate) overlaps with the semiconductor layer via the insulating layer 312 and the insulating layer 313. The two gates are preferably electrically connected.

[0119] The drive circuit 78 and the display unit 71 may have different transistor structures. The drive circuit 78 and the display unit 71 may both include transistors of multiple types.

[0120] By arranging transistors, wirings, and the like so as to overlap with the light-emitting region of the light-emitting element 110B, the aperture ratio of the display portion 71 can be increased.

[0121] It is preferred that a material in which impurities such as water or hydrogen are not easily diffused be used for at least one of the insulating layer 312, the insulating layer 313, and the insulating layer 314. This can effectively suppress the diffusion of impurities from the outside into the transistor, thereby improving the reliability of the display device. The insulating layer 314 is used as a planarization layer.

[0122] The insulating layer 367 has a function as a base film. The insulating layer 367 is preferably made of a material in which impurities such as water and hydrogen are not easily diffused.

[0123] The connection portion 306 includes a wiring 307. The wiring 307 can be formed using the same material and the same process as the source and drain of the transistor. The wiring 307 is electrically connected to an external input terminal that transmits a signal or potential from the outside to the drive circuit 78. Here, an example in which an FPC 74 is provided as an external input terminal is shown. The FPC 74 and the wiring 307 are electrically connected via a connector 319.

[0124] As the connection body 319 , various anisotropic conductive films (ACF: Anisotropic Conductive Film) and anisotropic conductive pastes (ACP: Anisotropic Conductive Paste) can be used.

[0125] The protective layer 117 preferably includes at least one inorganic film (or inorganic insulating film), and more preferably includes more than one inorganic film and more than one organic film. For example, the protective layer 117 may include a first inorganic film on the common electrode 115, an organic film on the first inorganic film, and a second inorganic film on the organic film.

[0126] The inorganic film (or inorganic insulating film) preferably has high moisture resistance and is not easy for water to diffuse and penetrate. Furthermore, the inorganic film (or inorganic insulating film) is preferably not easy for one or both of hydrogen and oxygen to diffuse and penetrate. Thus, the inorganic film (or inorganic insulating film) can be used as a barrier film. Moreover, impurities diffused from the outside to the light-emitting element can be effectively suppressed, so that a display device with high reliability can be realized.

[0127] As the protective layer 117, an oxide insulating film, a nitride insulating film, an oxynitride insulating film, a nitride oxide insulating film, or the like can be used. As the oxide insulating film, a silicon oxide film, an aluminum oxide film, a gallium oxide film, a germanium oxide film, an yttrium oxide film, a zirconium oxide film, a lanthanum oxide film, a neodymium oxide film, a hafnium oxide film, and a tantalum oxide film can be cited. As the nitride insulating film, a silicon nitride film and an aluminum nitride film can be cited. As the oxynitride insulating film, an oxynitride silicon film can be cited. As the nitride oxide insulating film, a silicon nitride oxide film can be cited.

[0128] In this specification and the like, an oxynitride refers to a material containing more oxygen than nitrogen in its composition, and an oxynitride refers to a material containing more nitrogen than oxygen in its composition.

[0129] In particular, a silicon nitride film, a silicon nitride oxide film, and an aluminum oxide film are all highly moisture resistant and thus are suitable for use as the protective layer 117 .

[0130] In addition, as the protective layer 117, an inorganic film including ITO, Ga-Zn oxide, Al-Zn oxide, In-Ga-Zn oxide, etc. can be used. The inorganic film preferably has a high resistance, and specifically, the inorganic film preferably has a higher resistance than the common electrode 115. The inorganic film may further contain nitrogen.

[0131] For example, the conductive film for the common electrode 115 that transmits visible light and the inorganic film for the protective layer 117 that transmits visible light may also have the same metal element. When the two films have the same metal element, the closeness between the common electrode 115 and the protective layer 117 can be improved, and film peeling and impurities intruding from the interface can be suppressed.

[0132] In addition, the protective layer 117 may include an organic insulating film using acrylic resin, epoxy resin, polyimide resin, polyamide resin, polyimide amide resin, polysiloxane resin, benzocyclobutene-based resin, phenolic resin, or the like.

[0133] The intrinsic resistance of the protective layer 117 at 20°C is preferably 10 10 Ωcm or more.

[0134] The protective layer 117 can be formed by a chemical vapor deposition (CVD) method (such as a plasma enhanced chemical vapor deposition (PECVD) method), a sputtering method (such as a DC sputtering method, an RF sputtering method, and an ion beam sputtering method), an atomic layer deposition (ALD) method, or the like.

[0135] Sputtering and ALD methods can realize low-temperature film formation. The EL layer 113 included in the light-emitting element has low heat resistance. Therefore, the protective layer 117 formed after manufacturing the light-emitting element is preferably formed at a relatively low temperature, typically below 100° C., preferably using sputtering and ALD methods.

[0136] As the protective layer 117 , two or more insulating films formed by different deposition methods may be stacked.

[0137] Note that as the insulating layer 104 , an inorganic insulating film or an organic insulating film which can be used for the protective layer 117 can be used.

[0138] The insulating layer 104 formed before manufacturing the light-emitting element can be formed at a high temperature. By setting the substrate temperature during film formation to a high temperature (for example, 100° C. or higher and 350° C. or lower), a dense film with high barrier properties can be formed. In addition to the sputtering method and the ALD method, it is also preferred to use the CVD method to form the insulating layer 104. The CVD method is preferred because of its high film formation speed.

[0139] The substrate 361 and the substrate 371 can be made of a material such as glass, quartz, an organic resin, a metal, an alloy, or a semiconductor.

[0140] The partition wall 107 may have a light-shielding property. Specifically, the partition wall 107 blocks light from an adjacent light-emitting element or color conversion layer, thereby suppressing color mixing between adjacent pixels. The partition wall 107 may be formed using, for example, a metal material or a resin material containing a pigment or a dye. Note that when the partition wall 107 has a light-shielding property, it is preferable to provide the partition wall 107 in a region other than the display portion such as a drive circuit, because light leakage due to waveguide light or the like can be suppressed.

[0141] Figure 6 A cross-sectional view showing a display device 10B is shown. Figure 7 A cross-sectional view of a display device 10C is shown, and Figure 8 10B, 10C, and 10D are shown in cross-sectional view. Figure 5A The display device 10A shown is identical. Figures 6 to 8 Equivalent to Figure 5A A cross-sectional view taken along the dashed line A1 - A2 is shown. Note that description of the same parts as those of the display device 10A may be omitted.

[0142] Figure 6 The display device 10B shown is a display device of a top emission structure.

[0143] The display device 10B includes a substrate 361, an adhesive layer 363, an insulating layer 365, transistors 301, 303, wiring 307, an insulating layer 314, a light-emitting element 110B, an insulating layer 104, a protective layer 117, a color conversion layer CCMR, a color conversion layer CCMG, an adhesive layer 317 and a substrate 371.

[0144] exist Figure 5B In the display device 10A shown in FIG. 1 , the color conversion layer CCMR and the color conversion layer CCMG are disposed on a substrate 371. Specifically, Figure 5B In the embodiment, the light emitting element 110B and the color conversion layer CCMR or the color conversion layer CCMG overlap each other via the protective layer 117 and the space 121. Figure 6In the display device 10B shown in FIG. 1 , the color conversion layer CCMR and the color conversion layer CCMG are provided in contact with the protective layer 117. Specifically, Figure 6 In the embodiment, the light emitting element 110B and the color conversion layer CCMR or the color conversion layer CCMG overlap with each other via the protective layer 117 , and the color conversion layer CCMR or the color conversion layer CCMG and the substrate 371 overlap with each other via the adhesive layer 317 .

[0145] In the case where the color conversion layer is directly formed on the protective layer 117, it is easier to align the position of the light-emitting region of the light-emitting element than in the case where the color conversion layer is formed on the substrate 371, so it is preferred. In the case where the color conversion layer is formed on the substrate 371, the range of choices of the formation method and formation conditions is wider than in the case where the color conversion layer is formed on the protective layer 117, so it is preferred.

[0146] The substrate 361 and the substrate 371 are bonded together by an adhesive layer 317. In addition, the substrate 361 and the insulating layer 365 are bonded together by an adhesive layer 363.

[0147] The display device 10B is formed by transferring transistors, light-emitting elements, and the like formed on a formation substrate onto a substrate 361. Each of the substrate 361 and the substrate 371 preferably has flexibility. Thus, the flexibility of the display device 10B can be improved.

[0148] The display device 10B is different from the display device 10A in the structure of the transistors 301 and 303 .

[0149] Figure 6 The transistors 301 and 303 shown include a back gate, a gate insulating layer 311, a semiconductor layer, a gate insulating layer, a gate, an insulating layer 315, a source and a drain. The semiconductor layer includes a channel formation region and a pair of low resistance regions. The back gate (the gate on the lower side) overlaps with the channel formation region through the gate insulating layer 311. The gate (the gate on the upper side) overlaps with the channel formation region through the gate insulating layer. The source and the drain are electrically connected to the low resistance region through an opening formed in the insulating layer 315.

[0150] Figure 7 The display device 10C shown is a display device with a bottom emission structure.

[0151] The display device 10C includes a substrate 361, an insulating layer 367, transistors 301 and 303, wiring 307, a conductive layer 355, an insulating layer 314, a light-emitting element 110B, an insulating layer 104, a protective layer 117, a color conversion layer CCMG, an adhesive layer 317, and a substrate 371.

[0152] In the pixel emitting green light, the light emitting element 110B overlaps the color conversion layer CCMG via the insulating layer 314. The blue light emitted from the light emitting element 110B is converted into green light by the color conversion layer CCMG, so that the green light 106G is extracted to the outside.

[0153] Since the color conversion layer is not provided in the pixel that exhibits blue light, the blue light 106B emitted from the light emitting element 110B is extracted to the outside through the insulating layer 314 .

[0154] The color conversion layer CCMG may be provided in contact with the top surface of any one of the plurality of insulating layers provided between the light emitting element 110B and the substrate 361. When the color conversion layer CCMG is provided on the insulating layer, it is easier to align the position of the light emitting region of the light emitting element than when the color conversion layer CCMG is provided on another substrate, so it is preferred.

[0155] The display device 10C has a bottom emission structure, and therefore the transistor 303 is provided at a position that does not overlap with the light emitting region of the light emitting element 110B. The transistor 303 is provided at a position that does not overlap with the insulating layer 104.

[0156] The connection portion 306 includes a wiring 307 and a conductive layer 355. The wiring 307 can be formed using the same material and the same process as the source and drain of the transistor. The conductive layer 355 can be formed using the same material and the same process as the pixel electrode 111. The wiring 307 is electrically connected to an external input terminal that transmits a signal or potential from the outside to the drive circuit 78. Here, an example in which an FPC 74 is provided as an external input terminal is shown. The FPC 74 and the wiring 307 are electrically connected through the conductive layer 355 and the connector 319.

[0157] Figure 8 The display device 10D shown is a display device with a bottom emission structure.

[0158] The display device 10D includes a substrate 361, an adhesive layer 363, an insulating layer 365, transistors 301, 303, wiring 307, a conductive layer 355, an insulating layer 314, a light-emitting element 110B, an insulating layer 104, a protective layer 117, a color conversion layer CCMG, a partition wall 107, an adhesive layer 317 and a substrate 371.

[0159] The display device 10D is formed by transferring transistors and light-emitting elements formed on a formation substrate onto a substrate 361. The color conversion layer can be formed on the formation substrate in the same manner as the transistors and light-emitting elements. Alternatively, the color conversion layer can be formed in advance on the substrate 361, and the surface exposed by peeling off the formation substrate and the color conversion layer can be bonded together. Figure 8The display device 10D shown is formed by attaching the insulating layer 365 exposed by peeling and the substrate 361 including the color conversion layer CCMG and the partition wall 107 together using the adhesive layer 363 .

[0160] When the color conversion layer is formed on the substrate 361, the color conversion layer does not affect the layout, structure, characteristics, etc. of the transistor or the light-emitting element. Therefore, compared with the case where the color conversion layer is formed on the formation substrate, the range of choices of formation methods and formation conditions is wider, so it is preferred.

[0161] In the pixel emitting green light, the light emitting element 110B overlaps the color conversion layer CCMG via the insulating layer 314 and the adhesive layer 363. The blue light emitted from the light emitting element 110B is converted into green light by the color conversion layer CCMG, and thus the green light 106G is extracted to the outside.

[0162] Since the color conversion layer is not provided in the pixel emitting blue light, the blue light 106B emitted from the light emitting element 110B is extracted to the outside through the insulating layer 314 and the adhesive layer 363 and the like.

[0163] [transistor] Next, transistors that can be used in a display device will be described.

[0164] There is no particular restriction on the transistor structure included in the display device. For example, a planar transistor, a staggered transistor, or an inversely staggered transistor may be used. In addition, the transistor may have a top gate structure or a bottom gate structure. Alternatively, gate electrodes may be provided above and below the channel.

[0165] As a transistor included in the display device, for example, a transistor using a metal oxide for a channel formation region can be used. Therefore, a transistor with extremely low off-state current can be realized.

[0166] Alternatively, a transistor included in a display device may include a transistor containing silicon in a channel formation region, such as a transistor containing amorphous silicon, a transistor containing crystalline silicon (typically low temperature polysilicon), and a transistor containing single crystal silicon.

[0167] Fig. 9A and Fig. 9B An example of the structure of a transistor is shown. Each transistor is provided between the insulating layer 141 and the insulating layer 208. The insulating layer 141 is preferably used as a base film. The insulating layer 208 is preferably used as a planarizing film.

[0168] Fig. 9A The transistor 220 shown is a bottom-gate structure transistor including metal oxide in the semiconductor layer 204. Metal oxide can be used as the oxide semiconductor.

[0169] As the semiconductor of the transistor, an oxide semiconductor is preferably used. This is preferable because the off-state current of the transistor can be reduced by using a semiconductor material having a wider band gap than silicon and a smaller carrier density than silicon.

[0170] The transistor 220 includes a conductive layer 201, an insulating layer 202, a conductive layer 203a, a conductive layer 203b, and a semiconductor layer 204. The conductive layer 201 is used as a gate. The insulating layer 202 is used as a gate insulating layer. The semiconductor layer 204 overlaps with the conductive layer 201 via the insulating layer 202. Both the conductive layer 203a and the conductive layer 203b are electrically connected to the semiconductor layer 204. The transistor 220 is preferably covered with an insulating layer 211 and an insulating layer 212. Various inorganic insulating films can be used as the insulating layer 211 and the insulating layer 212. In particular, as the insulating layer 211, an oxide insulating film is preferably used, and as the insulating layer 212, a nitride insulating film is preferably used.

[0171] Fig. 9B The transistor 230 shown is a bottom-gate structure transistor including polysilicon in a semiconductor layer.

[0172] The transistor 230 includes a conductive layer 201, an insulating layer 202, a conductive layer 203a, a conductive layer 203b, a semiconductor layer, and an insulating layer 213. The conductive layer 201 is used as a gate. The insulating layer 202 is used as a gate insulating layer. The semiconductor layer includes a channel formation region 214a and a pair of low resistance regions 214b. The semiconductor layer may also include an LDD (Lightly Doped Drain) region. Fig. 9B An example is shown in which an LDD region 214c is included between a channel forming region 214a and a low resistance region 214b. The channel forming region 214a overlaps with the conductive layer 201 via the insulating layer 202. The conductive layer 203a is electrically connected to one of a pair of low resistance regions 214b through an opening provided in the insulating layer 202 and the insulating layer 213. Similarly, the conductive layer 203b is electrically connected to the other of the pair of low resistance regions 214b. As the insulating layer 213, various inorganic insulating films can be used. In particular, as the insulating layer 213, a nitride insulating film is preferably used.

[0173] [Metal oxides] It is preferable to use a metal oxide used as an oxide semiconductor for the semiconductor layer. Hereinafter, the metal oxide that can be used for the semiconductor layer will be described.

[0174] The metal oxide preferably contains at least indium or zinc. In particular, it preferably contains indium and zinc. In addition, it preferably contains aluminum, gallium, yttrium or tin. Alternatively, it may contain one or more of boron, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten or magnesium.

[0175] Here, the case where the metal oxide is an In-M-Zn oxide containing indium, element M and zinc is considered. Note that element M is aluminum, gallium, yttrium or tin, etc. Other elements that can be used as element M include boron, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, etc. Note that as element M, a plurality of the above elements may be combined.

[0176] In this specification, etc., metal oxides containing nitrogen are sometimes also referred to as metal oxides. In addition, metal oxides containing nitrogen may also be referred to as metal oxynitrides. For example, metal oxides containing nitrogen such as zinc oxynitride (ZnON) may be used for semiconductor layers.

[0177] In this specification, etc., it may be described as CAAC (c-axis aligned crystal) or CAC (Cloud-Aligned Composite). Note that CAAC is an example of a crystal structure, and CAC is an example of a function or a material composition.

[0178] For example, CAC (Cloud-Aligned Composite)-OS can be used as the semiconductor layer.

[0179] CAC-OS or CAC-metal oxide has the function of conductivity in a part of the material, has the function of insulation in another part of the material, and has the function of semiconductor as a whole. In addition, when CAC-OS or CAC-metal oxide is used in the light-emitting layer of a transistor, the function of conductivity is to allow electrons (or holes) used as carriers to flow through, and the function of insulation is to prevent electrons used as carriers from flowing through. Through the complementary effects of the functions of conductivity and insulation, CAC-OS or CAC-metal oxide can have a switching function (a function of controlling on / off). By separating each function in CAC-OS or CAC-metal oxide, each function can be maximized.

[0180] In addition, CAC-OS or CAC-metal oxide includes a conductive region and an insulating region. The conductive region has the function of the above-mentioned conductivity, and the insulating region has the function of the above-mentioned insulation. In addition, in the material, the conductive region and the insulating region are sometimes separated with a nanoparticle level. In addition, the conductive region and the insulating region are sometimes distributed unevenly in the material. In addition, sometimes the conductive region whose edge is fuzzy and connected with a cloud shape is observed.

[0181] In CAC-OS or CAC-metal oxide, the conductive region and the insulating region may be dispersed in the material with a size of 0.5 nm to 10 nm, preferably 0.5 nm to 3 nm.

[0182] In addition, CAC-OS or CAC-metal oxide is composed of components with different band gaps. For example, CAC-OS or CAC-metal oxide is composed of a component with a wide gap caused by an insulating region and a component with a narrow gap caused by a conductive region. In this structure, when carriers are allowed to flow through, the carriers mainly flow through the component with the narrow gap. In addition, the component with the narrow gap interacts with the component with the narrow gap through the complementary effect with the component with the wide gap, so that the carriers flow through the component with the wide gap. Therefore, when the above-mentioned CAC-OS or CAC-metal oxide is used in the channel formation region of a transistor, a high current driving force, that is, a large on-state current and a high field effect mobility can be obtained in the on-state of the transistor.

[0183] That is, CAC-OS or CAC-metal oxide may also be referred to as a matrix composite material (matrix composite) or a metal matrix composite material (metal matrix composite).

[0184] Oxide semiconductors (metal oxides) are classified into single crystal oxide semiconductors and non-single crystal oxide semiconductors. Examples of non-single crystal oxide semiconductors include CAAC-OS (c-axis aligned crystalline oxide semiconductor), polycrystalline oxide semiconductors, nc-OS (nanocrystalline oxide semiconductor), a-like OS (amorphous-like oxide semiconductor), and amorphous oxide semiconductors.

[0185] CAAC-OS has c-axis orientation, and its multiple nanocrystals are connected in the ab plane direction and the crystal structure has distortion. Note that distortion refers to the part where the lattice arrangement direction changes between the region where the multiple nanocrystals are connected and the region where the lattice arrangement is consistent.

[0186] Although nanocrystals are basically hexagonal, they are not limited to regular hexagons, and there are cases where they are not regular hexagons. In addition, in the distortion, there is sometimes a lattice arrangement such as a pentagon or a heptagon. In addition, in CAAC-OS, it is difficult to observe a clear grain boundary even near the distortion. That is, it can be seen that the formation of grain boundaries can be suppressed due to the distortion of the lattice arrangement. This is because CAAC-OS can accommodate distortion due to the low density of oxygen atoms arranged in the ab plane direction or the change in the bonding distance between atoms caused by the substitution of metal elements.

[0187] CAAC-OS tends to have a layered crystal structure (also referred to as a layered structure) in which a layer containing indium and oxygen (hereinafter referred to as an In layer) and a layer containing element M, zinc, and oxygen (hereinafter referred to as an (M, Zn) layer) are stacked. In addition, indium and element M can replace each other. When indium replaces element M in the (M, Zn) layer, the layer can also be expressed as an (In, M, Zn) layer. In addition, when indium in the In layer is replaced by element M, the layer can also be expressed as an (In, M) layer.

[0188] CAAC-OS is a metal oxide with high crystallinity. On the other hand, it is not easy to observe clear grain boundaries in CAAC-OS, so it is not easy to cause a decrease in electron mobility due to grain boundaries. In addition, the crystallinity of metal oxides is sometimes reduced due to the entry of impurities or the generation of defects, so it can be said that CAAC-OS is a metal oxide with high crystallinity (oxygen vacancies (also called V O Therefore, the physical properties of the metal oxide including CAAC-OS are stable. Therefore, the metal oxide including CAAC-OS has high heat resistance and high reliability.

[0189] In nc-OS, the atomic arrangement in a tiny region (e.g., a region between 1 nm and 10 nm, especially a region between 1 nm and 3 nm) is periodic. In addition, in nc-OS, no regularity of crystal orientation is observed between different nanocrystals. Therefore, no orientation is observed in the entire film. Therefore, sometimes nc-OS is no different from a-like OS or amorphous oxide semiconductors in some analysis methods.

[0190] In addition, indium-gallium-zinc oxide (hereinafter, IGZO), which is a kind of metal oxide containing indium, gallium and zinc, sometimes has a stable structure when it is composed of the above-mentioned nanocrystal. In particular, IGZO has a tendency that it is not easy to grow crystals in the atmosphere, so sometimes IGZO is structurally stable when it is formed by small crystals (for example, the above-mentioned nanocrystals) than when it is formed by large crystals (here, crystals of several mm or several cm).

[0191] a-like OS is a metal oxide having a structure between nc-OS and amorphous oxide semiconductor. a-like OS contains voids or low-density regions. In other words, the crystallinity of a-like OS is lower than that of nc-OS and CAAC-OS.

[0192] Oxide semiconductors (metal oxides) have various structures and various characteristics. The oxide semiconductor of one embodiment of the present invention may include two or more of an amorphous oxide semiconductor, a polycrystalline oxide semiconductor, a-like OS, nc-OS, and CAAC-OS.

[0193] The metal oxide film used as the semiconductor layer can be formed using either or both of an inert gas and an oxygen gas. Note that there is no particular restriction on the oxygen flow rate ratio (oxygen partial pressure) when the metal oxide film is formed. However, in the case of obtaining a transistor with high field effect mobility, the oxygen flow rate ratio (oxygen partial pressure) when the metal oxide film is formed is preferably 0% or more and 30% or less, more preferably 5% or more and 30% or less, and further preferably 7% or more and 15% or less.

[0194] The energy gap of the metal oxide is preferably 2 eV or more, more preferably 2.5 eV or more, and further preferably 3 eV or more. Thus, by using a metal oxide with a wide energy gap, the off-state current of the transistor can be reduced.

[0195] The metal oxide film can be formed by a sputtering method, and other methods such as PLD, PECVD, thermal CVD, ALD, and vacuum evaporation can also be used.

[0196] As materials that can be used to form various conductive layers of display devices, metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum or tungsten or alloys with the above metals as main components can be cited. In addition, films containing these materials can be used in a single layer or a laminated structure. For example, a single layer structure of an aluminum film containing silicon, a two-layer structure of an aluminum film stacked on a titanium film, a two-layer structure of an aluminum film stacked on a tungsten film, a two-layer structure of a copper film stacked on a copper-magnesium-aluminum alloy film, a two-layer structure of a copper film stacked on a titanium film, a two-layer structure of a copper film stacked on a tungsten film, a three-layer structure of a titanium film or a titanium nitride film, an aluminum film or a copper film, and a titanium film or a titanium nitride film stacked in sequence, and a three-layer structure of a molybdenum film or a molybdenum nitride film, an aluminum film or a copper film, and a molybdenum film or a molybdenum nitride film stacked in sequence, etc. In addition, oxides such as indium oxide, tin oxide or zinc oxide can be used. In addition, by using copper containing manganese, the controllability of the shape during etching can be improved, so it is preferred.

[0197] Examples of insulating materials that can be used for each insulating layer constituting the display device include resins such as acrylic resins, polyimide, epoxy, and silicone, and inorganic insulating materials such as silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, and aluminum oxide.

[0198] As described above, in the display device of this embodiment, by combining a blue light-emitting element and a color conversion layer, a full-color display can be performed. In addition, the number of layers constituting the light-emitting element can be reduced, and the manufacturing device and the manufacturing process can be simplified. In addition, in the display device of this embodiment, in addition to the image signal corresponding to the image data, a signal (correction signal) corresponding to the correction data can also be supplied to the pixel. Therefore, the desired display can be performed without converting the image data.

[0199] This embodiment mode can be appropriately combined with other embodiment modes. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, these configuration examples can be appropriately combined.

[0200] (Implementation Method 2) In this embodiment, refer to FIG. 10A to FIG. 16B A pixel circuit included in a display device according to one embodiment of the present invention will be described.

[0201] [Display device] Fig. 10A 2 is a block diagram of a display device 15. The display device 15 includes a display unit 11 having a plurality of pixels PIX, a gate driver 13, and a source driver 14.

[0202] The pixel PIX includes at least one storage circuit MEM. The storage circuit MEM can maintain the potential of at least one storage node. The storage circuit MEM can also maintain the potentials of a plurality of storage nodes connected in series or in parallel. Fig. 10A Although not shown in the figure, the pixel PIX includes a display element (a light-emitting element in this embodiment) and a transistor for driving the display element. A signal is supplied to the pixel PIX from the gate driver 13 through a plurality of wirings GL to control the driving of the pixel PIX. A signal is supplied to the pixel PIX from the source driver 14 through a plurality of wirings DL to control the driving of the pixel PIX.

[0203] A plurality of wirings GL are used as scanning lines. The signal transmitted by the wiring GL is used as a scanning signal (also referred to as a control signal). The scanning signal is a signal used to control the conduction state or non-conduction state (on or off) of the transistor used as a switch in the pixel PIX. The signal transmitted by the wiring GL is output from the gate driver 13.

[0204] A plurality of wirings DL are used as data lines. The signals transmitted by the wirings DL are used as data signals. The data signals are also referred to as data, image data, or image signals. The data signals are signals used to display images. As data signals, in addition to the signals held in the storage circuit MEM, there are also signals supplied after the signals are held in the storage circuit MEM. The wirings DL are used as wirings for supplying voltages required for driving the pixels PIX, for example, wirings used as reference voltages. The signals transmitted by the wirings DL are output from the source driver 14.

[0205] The storage circuit MEM includes a capacitor and a transistor. The storage circuit MEM has a function of holding a signal supplied through the wiring DL as a charge (potential) in the capacitor. The storage circuit MEM has a function of holding a voltage obtained by adding the potential of the held potential to the potential of the signal written later by supplying another signal through the wiring DL. Specifically, the addition of signals can be performed by using capacitive coupling in the capacitor. Note that the operation of the storage circuit MEM of holding a signal supplied through the wiring DL as a charge in the capacitor is sometimes referred to as "holding a signal".

[0206] In the display device of this embodiment, since the pixel PIX includes the memory circuit MEM, the image data can be corrected in the pixel PIX.

[0207] [Structural Example 1 of Pixel Circuit] Fig. 10B The pixel 100 shown includes a transistor M1 , a transistor M2 , a transistor M3 , a transistor M4 , a transistor M5 , a capacitor C1 , a capacitor C2 , and a light emitting element 110 .

[0208] One of the source and drain of the transistor M1 is electrically connected to one electrode of the capacitor C2. The other electrode of the capacitor C2 is electrically connected to one of the source and drain of the transistor M4. One of the source and drain of the transistor M4 is electrically connected to the gate of the transistor M2. The gate of the transistor M2 is electrically connected to one electrode of the capacitor C1. The other electrode of the capacitor C1 is electrically connected to one of the source and drain of the transistor M2. One of the source and drain of the transistor M2 is electrically connected to one of the source and drain of the transistor M5. One of the source and drain of the transistor M5 is electrically connected to one of the source and drain of the transistor M3. The other of the source and drain of the transistor M5 is electrically connected to one electrode of the light emitting element 110. Fig. 10B Each of the transistors shown includes a back gate electrically connected to the gate. However, in the display device of this embodiment, there is no particular limitation on the presence or absence of a back gate of the transistor and the connection of the back gate.

[0209] Here, a node connected to the other electrode of capacitor C2, one of the source and drain of transistor M4, the gate of transistor M2, and one electrode of capacitor C1 is referred to as node ND1. In addition, a node connected to the other of the source and drain of transistor M5 and one electrode of light emitting element 110 is referred to as node ND2.

[0210] The gate of the transistor M1 is electrically connected to the wiring GL1. The gate of the transistor M3 is electrically connected to the wiring GL1. The gate of the transistor M4 is electrically connected to the wiring GL2. The gate of the transistor M5 is electrically connected to the wiring GL3. The other of the source and the drain of the transistor M1 is electrically connected to the wiring DL1. The other of the source and the drain of the transistor M3 is electrically connected to the wiring V0. The other of the source and the drain of the transistor M4 is electrically connected to the wiring DLW1.

[0211] The other of the source and the drain of the transistor M2 is electrically connected to the power supply line 187 (high potential). The other electrode of the light emitting element 110 is electrically connected to the common wiring 189. Note that the common wiring 189 can be supplied with an arbitrary potential.

[0212] Wiring GL1, GL2, and GL3 can be used as signal lines for controlling the operation of transistors. Wiring DL1 can be used as a signal line for supplying image signals to pixels. In addition, wiring DLW1 can be used as a signal line for writing data to storage circuit MEM. Wiring DLW1 can be used as a signal line for supplying correction signals to pixels. Wiring V0 is used as a monitoring line for obtaining the electrical characteristics of transistor M4. In addition, by supplying a specific potential from wiring V0 to one electrode of capacitor C1 through transistor M3, the writing of image signals can be stabilized.

[0213] The transistor M2, the transistor M4 and the capacitor C2 constitute a storage circuit MEM. The node ND1 is a storage node. By turning on the transistor M4, a signal supplied to the wiring DLW1 can be written to the node ND1. By using a transistor with an extremely low off-state current as the transistor M4, the potential of the node ND1 can be maintained for a long time.

[0214] As the transistor M4, for example, a transistor using a metal oxide in the channel formation region (hereinafter referred to as an OS transistor) can be used. As a result, the off-state current of the transistor M4 can be made extremely low, and the potential of the node ND1 can be maintained for a long time. In this case, an OS transistor is preferably used as other transistors constituting the pixel. For specific examples of metal oxides, reference can be made to the contents of Implementation 1. The atoms constituting the crystal in CAAC-OS are stable, and it is suitable for transistors that emphasize reliability, etc. CAC-OS exhibits high mobility characteristics, and is suitable for transistors that are driven at high speed, etc.

[0215] OS transistors have a large energy gap and extremely small off-state current. Unlike transistors including Si in the channel formation region (hereinafter referred to as Si transistors), OS transistors do not cause impact ionization, avalanche breakdown, short channel effects, etc., and can therefore form highly reliable circuits.

[0216] Alternatively, a Si transistor may be used as the transistor M4. In this case, it is preferable to use a Si transistor as other transistors constituting the pixel.

[0217] Examples of Si transistors include transistors containing amorphous silicon, transistors containing crystalline silicon (typically, low-temperature polysilicon), and transistors containing single-crystal silicon.

[0218] A pixel may also include both OS transistors and Si transistors.

[0219] In the pixel, a signal written to the node ND1 is capacitively coupled with an image signal supplied from the wiring DL1 and output to the node ND2. The transistor M1 may have a function of selecting a pixel. The transistor M5 may be used as a switch for controlling light emission of the light emitting element 110.

[0220] For example, when the signal written from the wiring DLW1 to the node ND1 is greater than the threshold voltage (V th ), the transistor M2 is turned on before the image signal is written to make the light emitting element 110 emit light. Therefore, it is preferable to provide the transistor M5 and turn on the transistor M5 after the potential of the node ND1 is fixed to make the light emitting element 110 emit light.

[0221] That is, if a desired correction signal is stored in the node ND1, the correction signal can be added to the supplied image signal. Note that the correction signal may be attenuated due to factors on the transmission path, and therefore it is preferable to generate the correction signal in consideration of the attenuation.

[0222] use Fig.11A and Fig. 11B The timing diagram shown is for Fig. 10B The operation of the pixel 100 shown in the figure is described in detail. In addition, as the correction signal (Vp) supplied to the wiring DLW1, a positive signal or a negative signal can be used, and the case of supplying a positive signal is described here. In addition, in the following description and timing diagram, "H" represents a high potential and "L" represents a low potential. In addition, in this embodiment, an ideal operation is described, and the detailed change of the potential due to the structure of the circuit, the operation timing, etc. is not considered in the distribution, coupling or loss of the potential.

[0223] First, refer to Fig.11AThe operation of writing the correction signal (Vp) to the node ND1 will be described. This operation can be performed for each frame, and the writing may be performed at least once before supplying the image signal. In addition, the correction signal is rewritten to the node ND1 by appropriately performing a refresh operation.

[0224] At time T1, the potential of wiring GL1 is set to "H", the potential of wiring GL2 is set to "L", the potential of wiring GL3 is set to "L", and the potential of wiring DL1 is set to "L", whereby transistor M1 is turned on and the potential of the other electrode of capacitor C2 becomes "L".

[0225] This operation is a reset operation performed before the capacitive coupling. Before time T1, the light emitting element 110 emits light in the previous frame. However, since the potential of the reset operation node ND1 changes and the current flowing through the light emitting element 110 changes, it is preferred to make the transistor M5 non-conductive to stop the light emitting element 110 from emitting light.

[0226] At time T2, the potential of wiring GL1 is set to "H", the potential of wiring GL2 is set to "H", the potential of wiring GL3 is set to "L", and the potential of wiring DL1 is set to "L", whereby transistor M4 is turned on and the potential of wiring DLW1 (correction signal (Vp)) is written into node ND1.

[0227] At time T3, the potential of wiring GL1 is set to "H", the potential of wiring GL2 is set to "L", the potential of wiring GL3 is set to "L", and the potential of wiring DL1 is set to "L", whereby transistor M4 is non-conductive and the correction signal (Vp) is held at node ND1.

[0228] At time T4, the potential of wiring GL1 is set to "L", the potential of wiring GL2 is set to "L", the potential of wiring GL3 is set to "L", and the potential of wiring DL1 is set to "L", thereby making transistor M1 non-conductive, thereby completing the writing of the correction signal (Vp).

[0229] Next, refer to Fig. 11B The operation of correcting the image signal (Vs) and the operation of causing the light emitting element 110 to emit light will be described.

[0230] At time T11, the potential of the wiring GL1 is set to "H", the potential of the wiring GL2 is set to "L", the potential of the wiring GL3 is set to "L", and the potential of the wiring DLW1 is set to "L", whereby the transistor M1 is turned on, and the potential of the wiring DL1 is added to the potential of the node ND1 through the capacitive coupling of the capacitor C2. That is, the node ND1 becomes a potential (Vs+Vp) obtained by adding the correction signal (Vp) to the image signal (Vs).

[0231] At time T12, the potentials of wiring GL1, GL2, GL3, and DLW1 are set to "L", whereby transistor M1 is turned off and the potential of node ND1 is fixed to Vs+Vp.

[0232] At time T13, the potential of wiring GL1 is set to "L", the potential of wiring GL2 is set to "L", the potential of wiring GL3 is set to "H", and the potential of wiring DLW1 is set to "L", whereby transistor M5 is turned on, the potential of node ND2 becomes Vs+Vp, and light emitting element 110 emits light. Strictly speaking, the potential of node ND2 is equivalent to subtracting the threshold voltage (V th ), where V th is a negligible minimum value.

[0233] The above is the correction work of the image signal (Vs) and the work of making the light-emitting element 110 emit light. Note that although the writing work of the correction signal (Vp) and the input work of the image signal (Vs) described above can be performed continuously, it is preferred to write the correction signal (Vp) to all pixels first and then perform the input work of the image signal (Vs). In one embodiment of the present invention, since the same image signal can be supplied to multiple pixels at the same time, the operation speed can be increased by writing the correction signal (Vp) to all pixels first.

[0234] [Pixel Circuit Configuration Example 2] Next, a pixel circuit in which a plurality of storage nodes are provided in series will be described. In this pixel circuit, a light emitting element can be operated according to the sum of a plurality of input data.

[0235] Fig. 12A The pixel 101 shown includes two capacitors, and can display according to the sum of a maximum of three data through capacitive coupling.

[0236] Fig. 12A shows a structure where two capacitors are connected in series, such as Fig. 12B As shown, more capacitors C1 to C n A structure connected in series. In this case, a transistor is added at the same time as a capacitor. One of the source and drain of the transistor is electrically connected to the wiring connecting one capacitor to another capacitor. That is, a node such as node ND12 is added.

[0237] The number n of capacitors connected in series is preferably 2 or more and 8 or less, more preferably 2 or more and 6 or less, and further preferably 2 or more and 4 or less. The more the number of capacitors, the higher the effect of one embodiment of the present invention. Note that, since transistors and signal lines need to be increased as the number of capacitors increases, problems such as a decrease in the aperture ratio and resolution of pixels and inability to ensure signal input time may sometimes occur. Therefore, it is preferred that the number n of capacitors connected in series be selected within the above range according to the intended use.

[0238] Fig. 12A The pixel 101 shown includes a transistor M11, a transistor M12, a transistor M13, a capacitor C11, a capacitor C12 and a circuit block 150. The circuit block 150 may include transistors, capacitors and a light emitting element, etc. The circuit block 150 will be described in detail later.

[0239] One of the source and drain of the transistor M11 is electrically connected to one electrode of the capacitor C11. One electrode of the capacitor C11 is electrically connected to the circuit block 150. The other electrode of the capacitor C11 is electrically connected to one of the source and drain of the transistor M12. One of the source and drain of the transistor M12 is electrically connected to one electrode of the capacitor C12. The other electrode of the capacitor C12 is electrically connected to one of the source and drain of the transistor M13.

[0240] Here, the wiring connected to one of the source and drain of the transistor M11, one electrode of the capacitor C11, and the circuit block 150 is referred to as a node ND13. In addition, the constituent elements of the circuit block 150 connected to the node ND13 can make the node ND13 in a floating state. In addition, the wiring connected to the other electrode of the capacitor C11, one of the source and drain of the transistor M12, and one electrode of the capacitor C12 is referred to as a node ND12. In addition, the wiring connected to one of the source and drain of the transistor M13 and the other electrode of the capacitor C12 is referred to as a node ND11.

[0241] The gate of the transistor M11 is electrically connected to the wiring GL11. The gate of the transistor M12 is electrically connected to the wiring GL12. The gate of the transistor M13 is electrically connected to the wiring GL13. The other of the source and the drain of the transistor M11 is electrically connected to the wiring DL11. The other of the source and the drain of the transistor M12 is electrically connected to the wiring DL12. The other of the source and the drain of the transistor M13 is electrically connected to the wiring DL13.

[0242] The wirings GL11, GL12, and GL13 may be used as signal lines for controlling the operation of transistors. The wiring DL11 may be used as a signal line for supplying first data. The wiring DL12 may be used as a signal line for supplying second data. The wiring DL13 may be used as a signal line for supplying third data.

[0243] Node ND11, node ND12, and node ND13 are storage nodes. By turning on transistor M11, first data supplied to wiring DL11 can be written to node ND13. By making transistor M11 non-conductive, first data can be maintained in node ND13. In addition, by turning on transistor M12, second data supplied to wiring DL12 can be written to node ND12. By making transistor M12 non-conductive, second data can be maintained in node ND12. In addition, by turning on transistor M13, third data supplied to wiring DL13 can be written to node ND11. By making transistor M13 non-conductive, third data can be maintained in node ND11.

[0244] By using transistors with extremely low off-state current as the transistors M11, M12, and M13, the potentials of the nodes ND13 and ND12 can be held for a long time. For example, an OS transistor can be used as the transistor.

[0245] The OS transistor can be used as other transistors included in the pixel. In addition, the transistor included in the pixel can also use a Si transistor. Alternatively, both the OS transistor and the Si transistor can be used.

[0246] Reference Fig.13A , Fig. 13B and Fig. 13C The timing chart shown in FIG. 1 illustrates an example of the operation of the pixel 101 in which the second data and the third data are added to the first data. Note that in the following description, the first data is represented as “V data1 ", the second data is represented as "V data2 ”, and the third data is represented as “V data3 In addition, one of the reference potentials (for example, 0 V, GND potential, or a specific potential) is represented as “V ref ". Note that the first data, the second data and the third data can also be negative values, respectively, and also correspond to data subtraction.

[0247] First, refer to Fig.13A Description The first data "V data1 ” is written to the work of node ND13.

[0248] At time T1, the potential of the wiring GL11 is set to "H", the potential of the wiring GL12 is set to "H", and the potential of the wiring DL11 is set to "Vdata1 ”, so that the potential of the wiring DL12 is “V ref ”, whereby the transistor M12 is turned on and the potential of the node ND12 becomes “V ref ". This work is the reset work performed before the capacitive coupling.

[0249] In addition, the transistor M11 is turned on, and the potential of the wiring DL11 (the first data “V data1 ”).

[0250] At time T2, the potential of wiring GL11 is set to “L”, and the potential of wiring GL12 is set to “L”, thereby turning off transistors M11 and M12, and holding the first data “V data1 In addition, capacitor C11 holds "V data1 -V ref ”.

[0251] Here is the first data "V data1 In addition, when the first data is not reflected in the display, the first data "V data1 ”Supply and “V ref "The same potential is sufficient.

[0252] Next, refer to Fig. 13B Description The second data "V data2 ” is written to the work of node ND12.

[0253] At time T11, the potential of the wiring GL12 is set to "H", the potential of the wiring GL13 is set to "H", and the potential of the wiring DL12 is set to "V data2 ”, so that the potential of the wiring DL13 is “V ref ”, whereby the transistor M13 is turned on and the potential of the node ND11 becomes “V ref ". This work is the reset work performed before the capacitive coupling.

[0254] In addition, the transistor M12 is turned on, and the potential of the wiring DL12 (the second data “V data2 ”).

[0255] At this time, the potential of the node ND12 is added to the potential of the node ND13 by the capacitive coupling of the capacitor C11. Therefore, the potential of the node ND13 is "V data1 -V ref +V data2 ”, in “V ref ”=0, the potential of node ND13 is “V data1 +V data2 ”.

[0256] At time T12, the potential of wiring GL12 is set to “L”, and the potential of wiring GL13 is set to “L”, thereby turning off transistor M12 and retaining the second data “V data2 In addition, the node ND13 holds the sum of the first data and the second data. data1 +V data2 In addition, capacitor C12 holds "V data2 -V ref ”.

[0257] Here is the second data "V data2 "Write operation. In addition, when the second data is not reflected in the display, the second data "V data2 ”Supply and “V ref "The same potential is sufficient.

[0258] Next, refer to Fig. 13C Description Write the third data "V data3 ” work.

[0259] At time T21, the potential of the wiring GL13 is set to "H", and the potential of the wiring DL13 is set to "V data3 ”, whereby the transistor M13 is turned on and the potential of the node ND11 becomes “V data3 ”.

[0260] At this time, the potential of the node ND11 is added to the potential of the node ND12 by the capacitive coupling of the capacitor C12. Therefore, the potential of the node ND12 is "V data2 -V ref +V data3 ”, in “V ref ”=0, the potential of node ND12 is “V data2 +V data3 ”.

[0261] Furthermore, the potential of the node ND12 is added to the potential of the node ND13 by the capacitive coupling of the capacitor C11. Therefore, the potential of the node ND12 is “V data1 +V data2 +V data3 ”.

[0262] At time T22, the potential of wiring GL13 is set to “L”, thereby turning off transistor M13 and maintaining the potential of node ND13 at “V data1 +V data2 +V data3 ”.

[0263] As mentioned above, the first data "V data1 ", the second data "V data2" and the third data "V data3 "The writing work is completed. In addition, when the third data is not reflected in the display, the third data "V data3 ”Supply and “V ref " The same potential can be used. Alternatively, the writing of the third data can be omitted.

[0264] Then, a display operation corresponding to the potential of the node ND13 is performed in the light emitting element included in the circuit block 150. Note that, depending on the structure of the circuit block, the display operation may be performed from time T1 or time T11.

[0265] In addition, if Fig.14A , Fig. 14B and Fig. 14C As shown, you can also replace Fig.13A The work shown and Fig. 13B The order of work shown.

[0266] Reference Fig.14A Description The first data "V data2 ” is written to the work of node ND12.

[0267] At time T1, the potential of the wiring GL12 is set to "H", the potential of the wiring GL13 is set to "H", and the potential of the wiring DL12 is set to "V data2 ”, so that the potential of the wiring DL13 is “V ref ”, whereby the transistor M13 is turned on and the potential of the node ND11 becomes “V ref In addition, the transistor M12 is turned on, and the potential of the wiring DL12 (the second data “V data2 ”).

[0268] At time T2, the potential of wiring GL12 is set to "L", the potential of wiring GL13 is set to "L", transistors M12 and M13 are turned off, and the second data "V data2 In addition, capacitor C12 holds "V data2 -V ref ”.

[0269] First, refer to Fig. 14B Description The first data "V data1 ” is written to the work of node ND13.

[0270] At time T11, the potential of the wiring GL11 is set to "H", the potential of the wiring GL12 is set to "H", and the potential of the wiring DL11 is set to "V data1 ”, so that the potential of the wiring DL12 is “V ref ”, whereby the transistor M12 is turned on and the potential of the node ND12 becomes “Vref In addition, the transistor M11 is turned on, and the potential of the wiring DL11 (the first data “V data1 ”).

[0271] At time T12, the potential of wiring GL11 is set to "L", and the potential of wiring GL12 is set to "L", so that transistor M12 is turned off and "V ref In addition, the first data “V data1 In addition, since capacitor C12 holds "V data2 -V ref ”, so in “V ref ”=0, the potential of node ND11 is “-V data2 ”.

[0272] Next, refer to Fig. 14C Description Write the third data "V data3 ” work.

[0273] At time T21, the potential of the wiring GL13 is set to "H", and the potential of the wiring DL13 is set to "V data3 ”, whereby the transistor M13 is turned on and the potential of the node ND11 becomes “V data3 ”.

[0274] At this time, the potential of the node ND11 is added to the potential of the node ND12 by the capacitive coupling of the capacitor C12. Therefore, the potential of the node ND12 is "V data3 -(-V data2 )+V ref ”, in “V ref ”=0, the potential of node ND12 is “V data2 +V data3 ”.

[0275] Furthermore, the potential of the node ND12 is added to the potential of the node ND13 by the capacitive coupling of the capacitor C11. Therefore, the potential of the node ND13 is “V data1 +V data2 +V data3 ”.

[0276] At time T22, the potential of wiring GL13 is set to “L”, thereby turning off transistor M13 and maintaining the potential of node ND13 at “V data1 +V data2 +V data3 ”.

[0277] As mentioned above, the first data "V data1 ", the second data "V data2 " and the third data "Vdata3 The writing of " is completed.

[0278] Notice, Fig.13A , Fig. 13B and Fig. 13C The work can be performed continuously during a horizontal period. Fig.13A The work is performed on the kth frame (k is a natural number). Fig. 13B and Fig. 13C The work is performed on the k+1th frame. Alternatively, Fig.13A and Fig. 13B The work is performed on the kth frame. Fig. 13C The work is performed on the k+1 frame. Or you can also Fig.13A , Fig. 13B and Fig. 13C The work is performed in different consecutive frames. Alternatively, Fig.13A The work is performed on the kth frame. Fig. 13B and Fig. 13C The work is repeated after the k+1th frame. Alternatively, Fig.13A and Fig. 13B The work is performed on the kth frame. Fig. 13C The work is repeated after the k+1th frame. In addition, Fig.14A , Fig. 14B and Fig. 14C The work can be done in the same way.

[0279] FIG. 15A to FIG. 15C A specific example of the circuit block 150 is shown.

[0280] Fig.15A The circuit block 150 shown includes a transistor 171, a capacitor 173, and a light emitting element 110. One of the source and the drain of the transistor 171 is electrically connected to one electrode of the light emitting element 110. One electrode of the light emitting element 110 is electrically connected to one electrode of the capacitor 173. The other electrode of the capacitor 173 is electrically connected to the gate of the transistor 171. The gate of the transistor 171 is electrically connected to the node ND13.

[0281] The other of the source and the drain of the transistor 171 is electrically connected to a power supply line 187 (high potential). The other electrode of the light-emitting element 110 is electrically connected to a common wiring 189. Note that the common wiring 189 can be supplied with an arbitrary potential (for example, a low potential).

[0282] exist Fig.15A In the structure shown in FIG. 1 , when the potential of the node ND13 becomes equal to or higher than the threshold voltage of the transistor 171, current flows through the light emitting element 110. Therefore, the light emission of the light emitting element 110 may be Fig.13A and Fig.14AThe phase begins at time T1 of the timing diagram shown, so the usefulness of this structure may be limited.

[0283] Fig. 15B Yes Fig.15A The structure of the transistor 172 is added. One of the source and the drain of the transistor 172 is electrically connected to one of the source and the drain of the transistor 171. The other of the source and the drain of the transistor 172 is electrically connected to the light emitting element 110. The gate of the transistor 172 is electrically connected to the wiring 186. The wiring 186 can have a function as a signal line for controlling conduction of the transistor 172.

[0284] In this structure, when the potential of the node ND13 is equal to or higher than the threshold voltage of the transistor 171 and the transistor 172 is turned on, current flows through the light emitting element 110. Therefore, the light emitting element 110 can emit light at Fig. 13C and Fig. 14C The timing chart shown starts after time T22, so that the structure is suitable for operation with correction.

[0285] Fig. 15C Yes Fig. 15B The structure of the transistor 175 is added. One of the source and the drain of the transistor 175 is electrically connected to one of the source and the drain of the transistor 171. The other of the source and the drain of the transistor 175 is electrically connected to the wiring 190. The gate of the transistor 175 is electrically connected to the wiring 191. The wiring 191 can have a function as a signal line for controlling conduction of the transistor 175. Note that the gate of the transistor 175 can also be electrically connected to the wiring GL13.

[0286] The wiring 190 can be electrically connected to a supply source of a specific potential such as a reference potential. By supplying a specific potential from the wiring 190 to one of the source and the drain of the transistor 171, writing of image data can be stabilized.

[0287] In addition, the wiring 190 may be connected to the circuit 120 and may have a function of a monitoring line. The circuit 120 may have one or more of a function of supplying the above-mentioned specific potential, a function of obtaining the electrical characteristics of the transistor 171, and a function of generating correction data.

[0288] When the wiring 190 is used as a monitor line, for example, a potential of the threshold voltage of the correction transistor 171 is generated in the circuit 120 as data to be written in the node ND13 .

[0289] Next, refer to Fig.16A and Fig. 16B The correction operation of image data will be described.

[0290] Fig.16AAn example of data potential input to four pixels (P1 to P4) arranged in a 2×2 matrix is ​​shown. The generated image data is the sum of the first data (+A1, +A2, -A1, A0), the second data (+B1, B0, B0, -B1) and the third data (+C3, C2, C2, +C1). In each pixel, display can be performed based on the sum of the first data to the third data, and correction of the original image data can be performed.

[0291] For example, the first data and the second data may be data used for correction. In addition, the third data may be original image data.

[0292] By combining correction data and image data in this way, up-conversion, HDR display, correction of display unevenness inherent to the display device, correction of the threshold voltage of transistors included in pixels, etc. can be performed. Alternatively, the above operations can be performed in combination.

[0293] In the up-conversion operation, for example, the same image data is supplied to all four pixels, and different images can be displayed at each pixel according to the correction data. For example, image data for a specific pixel of 4K2K data can be input to specific four pixels of a display device including 8K4K pixels, and the resolution can be increased by the correction data input to each pixel for display.

[0294] By using the same image data as the first data to the third data, the brightness of the displayed image can be greatly improved. In this operation, since a voltage higher than the maximum output value of the column driving circuit can be supplied to the pixel, not only the image quality can be improved, but also the product cost can be reduced, such as reducing power consumption or using a cheap driver IC chip.

[0295] In addition, in a broad sense, it is a correction of image data, but different images can be displayed in an overlapping manner. Fig. 16B An image showing the entire display unit is shown, showing a first image composed of first data, a second image composed of second data, a third image composed of third data, and an image synthesized from the first image, the second image, and the third image.

[0296] Such a combination of different image data can be applied to, for example, character insertion or AR (Augmented Reality) display.

[0297] As described above, by using an image signal (image data) and a correction signal (correction data) to make the light-emitting element emit light, the current flowing through the light-emitting element can be increased, so that high brightness can be displayed. Therefore, image correction such as up-conversion of the image, HDR display that corrects a part or the entire image in the display area, or improvement of the brightness of the displayed image can be performed. In addition, multiple images can be displayed overlappingly. In addition, a voltage higher than the output voltage of the source driver can be applied as the gate voltage of the driving transistor, so the power consumption of the source driver can be reduced.

[0298] This embodiment mode can be combined with other embodiment modes as appropriate.

[0299] (Implementation 3) In this embodiment, materials that can be used for the light-emitting element are described.

[0300] [Material of light-emitting element] The following example can be used FIG. 4A to FIG. 4D The material of each layer of the light emitting element is shown. Note that each layer is not limited to a single layer, and two or more layers may be stacked.

[0301] <First Electrode and Second Electrode> As materials for forming the first electrode 1101 and the second electrode 1102, if the functions of the above two electrodes can be satisfied, the following materials can be appropriately combined. For example, metals, alloys, conductive compounds and mixtures thereof can be appropriately used. Specifically, In-Sn oxide (also known as ITO), In-Si-Sn oxide (also known as ITSO), In-Zn oxide, and In-W-Zn oxide can be cited. In addition to the above, aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd) and other metals and alloys appropriately combined therewith can also be cited. In addition to the above, elements belonging to Group 1 or Group 2 of the periodic table (for example, lithium (Li), cesium (Cs), calcium (Ca), strontium (Sr)), rare earth metals such as europium (Eu), ytterbium (Yb), alloys appropriately combined therefrom, and graphene, etc. can be used.

[0302] <Luminous Layer> The light-emitting layer 1113 is a layer containing a light-emitting substance. As described in Embodiment 1, the light-emitting substance is not particularly limited. For example, a fluorescent material, a phosphorescent material, a TADF material, a quantum dot material, and a metal halide perovskite can be used as the light-emitting substance.

[0303] Pyrene derivatives have high luminescence quantum yields and are therefore preferably used as fluorescent materials that emit blue light. Specific examples of pyrene derivatives include N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluorene-9-yl)phenyl]pyrene-1,6-diamine (abbreviated as 1,6mMemFLPAPrn), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluorene-9-yl)phenyl]pyrene-1,6-diamine (abbreviated as 1,6FLPAPrn), N,N'-bis(dibenzofuran-2-yl)-N,N'-diphenylpyrene-1,6-diamine (abbreviated as 1,6FrAPrn), N,N'-bis(dibenzothiophene-2-yl)-N,N' -diphenylpyrene-1,6-diamine (abbreviation: 1,6ThAPrn), N,N'-(pyrene-1,6-diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-6-amine] (abbreviation: 1,6BnfAPrn), N,N'-(pyrene-1,6-diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-02), N,N'-(pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), etc.

[0304] In addition, a polymer compound can also be used as the light-emitting layer 1113. For example, as a material emitting blue light, poly(9,9-dioctylfluorene-2,7-diyl) (abbreviated as POF), poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,5-dimethoxybenzene-1,4-diyl)] (abbreviated as PF-DMOP), poly{(9,9-dioctylfluorene-2,7-diyl)-co-[N,N'-di-(p-butylphenyl)-1,4-diaminobenzene]} (abbreviated as TAB-PFH), etc. can be cited.

[0305] Examples of phosphorescent materials that exhibit blue or green color and have an emission spectrum with a peak wavelength of 450 nm to 570 nm include the following.

[0306] For example, tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviated as [Ir(mpptz-dmp)3]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazole)iridium(III) (abbreviated as [Ir(Mptz)3]), tris[4-(3-biphenyl)-iridium(III)] (abbreviated as [Ir(Mptz)3]), organic metal complexes having a 4H-triazole skeleton, such as tris[3-(5-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazole]iridium(III) (abbreviated as [Ir(iPrptz-3b)3]), tris[3-(5-biphenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazole]iridium(III) (abbreviated as [Ir(iPr5btz)3]); tris[3-(5-biphenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazole]iridium(III) (abbreviated as [Ir(iPr5btz)3]); -5-phenyl-1H-1,2,4-triazole]iridium (III) (abbreviated as [Ir(Mptz1-mp)3]), tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazole)iridium (III) (abbreviated as [Ir(Prptz1-Me)3]), etc. having a 1H-triazole skeleton; fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium (III) (abbreviated as [Ir(iPrpmi)3]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium (III) (abbreviated as [Ir(dmpimpt-Me)3]), etc. having an imidazole skeleton; and bis[2-(4',6'-difluorophenyl)pyridinium-N,C 2 '] iridium (III) tetrakis (1-pyrazolyl) borate (abbreviated as FIr6), bis [2-(4', 6'-difluorophenyl) pyridinium-N, C 2 '] iridium (III) picolinate (abbreviated as FIrpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinium-N,C 2 '}iridium(III) picolinate (abbreviated as [Ir(CF3ppy)2(pic)]), bis[2-(4',6'-difluorophenyl)pyridinium-N,C 2 '] iridium (III) acetylacetonate (abbreviated as FIr(acac)) and other organic metal complexes with phenylpyridine derivatives having electron-withdrawing groups as ligands.

[0307] In addition, as a blue light-emitting substance, it is preferable to use a substance having a peak wavelength of photoluminescence of 430 nm to 470 nm, and more preferably a substance having a peak wavelength of 430 nm to 460 nm. In addition, a solution or a thin film can be used for the measurement of photoluminescence.

[0308] By using the above-mentioned compound and the microcavity effect at the same time, the above-mentioned chromaticity can be more easily achieved. At this time, the thickness of the semi-transmissive-semi-reflective electrode (metal film part) required to obtain the microcavity effect is preferably greater than 20nm and less than 40nm, more preferably greater than 25nm and less than 40nm. When the thickness exceeds 40nm, the efficiency may be reduced.

[0309] The light-emitting layer 1113 may include one or more organic compounds (host material, auxiliary material) in addition to the light-emitting substance (guest material). As the organic compound, a substance having an energy gap greater than that of the light-emitting substance may be used. In addition, as the one or more organic compounds, one or both of a compound that easily receives holes (hole transport material) and a compound that easily receives electrons (electron transport material) may be used.

[0310] When the luminescent material is a fluorescent material, it is preferred to use an organic compound with a large energy level of a singlet excited state and a small energy level of a triplet excited state as a host material. For example, an anthracene derivative or a tetracene derivative is preferably used. Specifically, 9-phenyl-3-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviated as: PCzPA), 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviated as: PCPN), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviated as: CzPA), 7-[4-(10-phenyl-9-anthracenyl)phenyl]-7H-dibenzo[ c, g] carbazole (abbreviation: cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthracenyl)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), 5,12-diphenyl tetracene, 5,12-bis(biphenyl-2-yl) tetracene, etc.

[0311] In the case where the luminescent material is a phosphorescent material, an organic compound whose triplet excitation energy (energy difference between the ground state and the triplet excited state) is larger than that of the luminescent material can be selected as the host material. In this case, zinc metal complexes or aluminum metal complexes, oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, pyrimidine derivatives, triazine derivatives, pyridine derivatives, bipyridine derivatives, phenanthroline derivatives, aromatic amines or carbazole derivatives can be used.

[0312] Specifically, metal complexes such as tris(8-hydroxyquinoline)aluminum(III) (abbreviated as Alq), tris(4-methyl-8-hydroxyquinoline)aluminum(III) (abbreviated as Almq3), 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); 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated as PBD), 1,3- Heterocyclic compounds such as bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 3-(4-biphenyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 2,2',2"-(1,3,5-benzenetriyl)-tri(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), bathophenanthroline (abbreviation: BPhen), bathocuproin (abbreviation: BCP), 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), and aromatic amine compounds such as NPB, TPD, and BSPB.

[0313] In addition, anthracene derivatives, phenanthrene derivatives, pyrene derivatives, (chrysene) derivatives, dibenzo[g,p] Condensed polycyclic aromatic compounds such as derivatives. Specifically, 9,10-diphenylanthracene (abbreviation: DPAnth), N,N-diphenyl-9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole-3-amine (abbreviation: CzA1PA), 4-(10-phenyl-9-anthracenyl)triphenylamine (abbreviation: DPhPA), YGAPA, PCAPA, N,9-diphenyl-N-{4-[4-(10-phenyl-9-anthracenyl)phenyl]phenyl}-9H-carbazole-3-amine (abbreviation: PCAPBA), 9,10-diphenyl-2-[N-phenyl-N-(9-phenyl-9H-carbazole-3-yl)amino]anthracene (abbreviation: 2PCAPA), 6,12-dimethoxy-5,11-diphenyl N,N,N',N',N",N",N"',N"'-octaphenyldibenzo[g,p] -2,7,10,15-tetramine (abbreviation: DBC1), 9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: CzPA), 3,6-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: DPCzPA), 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 9,9'-bianthracene (abbreviation: BANT), 9,9'-(phenylethylene-3,3'-diyl)phenanthrene (abbreviation: DPNS), 9,9'-(phenylethylene-4,4'-diyl)phenanthrene (abbreviation: DPNS2) and 1,3,5-tri(1-pyrenyl)benzene (abbreviation: TPB3), etc.

[0314] When a plurality of organic compounds are used for the light-emitting layer 1113, it is preferable to mix a compound that forms an exciplex and a light-emitting substance. In this case, various organic compounds can be used in combination as appropriate, but in order to efficiently form an exciplex, it is particularly preferable to combine a hole transport material and an electron transport material.

[0315] TADF material refers to a material that can use tiny thermal energy to convert the triplet excited state into a singlet excited state (reverse intersystem crossing) and efficiently present luminescence (fluorescence) from the singlet excited state. The condition for efficiently obtaining thermally activated delayed fluorescence is that the energy difference between the triplet excited energy level and the singlet excited energy level is greater than 0eV and less than 0.2eV, preferably greater than 0eV and less than 0.1eV. The delayed fluorescence emitted by the TADF material refers to luminescence with the same spectrum as general fluorescence but with a very long lifetime. Its lifetime is 10 -6 More than 10 seconds, preferably 10 -3 seconds or more.

[0316] Examples of TADF materials include fullerene or its derivatives, acridine derivatives such as prussicin, eosin, etc. In addition, metal-containing porphyrins including magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd) can be cited. As metal-containing porphyrins, for example, protoporphyrin-tin fluoride complex (abbreviated as SnF2(Proto IX)), mesoporphyrin-tin fluoride complex (abbreviated as SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (abbreviated as SnF2(Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (abbreviated as SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complex (abbreviated as SnF2(OEP)), protoporphyrin-tin fluoride complex (abbreviated as SnF2(Etio I)) and octaethylporphyrin-platinum chloride complex (abbreviated as PtCl2OEP) can be mentioned.

[0317] In addition to the above, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazole-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2-[4-(10H-phenoxazine-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4-(5-phenyl- The invention relates to heterocyclic compounds having π-electron-rich heteroaromatic rings and π-electron-deficient heteroaromatic rings, such as 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-oxanthene-9-one (abbreviation: ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridinium)phenyl]sulfone (abbreviation: DMAC-DPS), and 10-phenyl-10H,10'H-spiro[acridin-9,9'-anthracene]-10'-one (abbreviation: ACRSA). In addition, in a substance in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded, the donor property of the π-electron-rich heteroaromatic ring and the acceptor property of the π-electron-deficient heteroaromatic ring are both strong, and the energy difference between the singlet excited state and the triplet excited state becomes small, so it is particularly preferred.

[0318] In addition, when using a TADF material, it can be combined with other organic compounds.

[0319] <Hole Injection Layer and Hole Transport Layer> The hole-injection layer 1111 is a layer that injects holes from the first electrode 1101 of the anode or the charge-generating layer 1109 into the EL layer 1103B or the light-emitting unit 1123B and includes a layer with high hole-injection properties.

[0320] As materials with high hole injection properties, transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide can be cited. In addition to the above, phthalocyanine compounds such as phthalocyanine (abbreviated as: H2Pc), copper phthalocyanine (CuPc), etc.; aromatic amine compounds such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as: DPAB), N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviated as: DNTPD), etc.; or polymers such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (abbreviated as: PEDOT / PSS), etc. can be used.

[0321] As a material with high hole injection properties, a composite material containing a hole transport material and an acceptor material (electron acceptor material) can also be used. In this case, the acceptor material extracts electrons from the hole transport material to generate holes in the hole injection layer 1111, and the holes are injected into the light-emitting layer 1113 through the hole transport layer 1112. In addition, the hole injection layer 1111 can be a single layer composed of a composite material containing a hole transport material and an acceptor material (electron acceptor material), or a stack of layers formed using hole transport materials and acceptor materials (electron acceptor materials) respectively.

[0322] The hole transport layer 1112 is a layer that transports holes injected from the first electrode 1101 through the hole injection layer 1111 to the light-emitting layer 1113. The hole transport layer 1112 is a layer containing a hole transport material. As the hole transport material used for the hole transport layer 1112, it is particularly preferred to use a material having a HOMO energy level that is the same as or close to the HOMO energy level of the hole injection layer 1111.

[0323] As an acceptor material for the hole injection layer 1111, an oxide of a metal belonging to Group 4 to Group 8 in the periodic table can be used. Specifically, molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide can be cited. Molybdenum oxide is particularly preferably used because it is also stable in the atmosphere, has low hygroscopicity, and is easy to handle. In addition to the above, organic acceptors such as quinone dimethane derivatives, tetrachlorobenzoquinone derivatives, and hexaazatriphenylene derivatives can be cited. Specifically, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviated as: F4-TCNQ), chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviated as: HAT-CN) and the like can be used.

[0324] As the hole-transporting material used for the hole injection layer 1111 and the hole transport layer 1112, it is preferable that the hole-transporting material has 10 - 6 cm 2 In addition, any substance other than the above may be used as long as the hole transport property is higher than the electron transport property.

[0325] As hole transport materials, it is preferred to use π-electron-rich heteroaromatic compounds (for example, carbazole derivatives or indole derivatives) or aromatic amine compounds, and specific examples are as follows: 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as: NPB or α-NPD), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviated as: TPD), 4,4'-bis[N-(spiro-9,9'-difluorene-2-yl)-N-phenylamino]biphenyl (abbreviated as: BSPB), 4-phenyl-4'-(9-phenylfluorene)- -9-yl) triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl) triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl) triphenylamine (abbreviation: PCBA1BP), 3-[4-(9-phenanthrenyl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPPn), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole-3-amine (abbreviation: PCBiF), N-(1,1'-biphenyl-4-yl)-N- [4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as PCBBiF), 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 PCBANBB), 9,9-dimethyl-N-phenyl-N-[4-(9 Compounds having an aromatic amine skeleton such as N-phenyl-9H-carbazole-3-yl)phenyl]spiro-9,9'-difluorene-2-amine (abbreviated as: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]spiro-9,9'-difluorene-2-amine (abbreviated as: PCBASF), 4,4',4"-tris(carbazole-9-yl)triphenylamine (abbreviated as: TCTA), 4,4',4"-tris(N,N-diphenylamino)triphenylamine (abbreviated as: TDATA), 4,4',4"-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviated as: MTDATA);1,3-bis(N-carbazolyl)benzene (abbreviated as mCP), 4,4'-bis(N-carbazolyl)biphenyl (abbreviated as CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviated as CzTP), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviated as PCCP), 3-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviated as PCz PCA1), 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), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviated as TCPB), 9-[4-(10-phenyl-9 -anthryl)phenyl]-9H-carbazole (abbreviated as CzPA), etc.; 4,4',4"-(benzene-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), 4-[4-(9-phenyl-9H-fluorene-9-yl)phenyl]dibenzothiophene (abbreviated as DBTFLP-III), Compounds having a thiophene skeleton such as 4,4',4"-(benzene-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).

[0326] Furthermore, high molecular weight compounds such as poly(N-vinylcarbazole) (abbreviated as PVK), poly(4-ethylenetriphenylamine) (abbreviated as PVTPA), poly[N-(4-{N'-[4-(4-diphenylamine)phenyl]phenyl-N'-aniline}phenyl)methacrylamide] (abbreviated as PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviated as Poly-TPD) can also be used.

[0327] Note that the hole-transport material is not limited to the materials described above, and a combination of one or more of various known materials can be used as a hole-transport material for the hole-injection layer 1111 and the hole-transport layer 1112 .

[0328] <Electron Transport Layer> The electron transport layer 1114 is a layer that transports electrons injected from the second electrode 1102 through the electron injection layer 1115 to the light-emitting layer 1113. The electron transport layer 1114 is a layer containing an electron transport material. The electron transport material used for the electron transport layer 1114 preferably has a 1×10 -6 cm 2 In addition, any substance other than the above may be used as long as the electron transport property is higher than the hole transport property.

[0329] Examples of electron transporting materials include metal complexes having quinoline ligands, benzoquinoline ligands, oxazole ligands, thiazole ligands, oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, pyridine derivatives, bipyridine derivatives, etc. In addition to the above, π-electron-deficient heteroaromatic compounds such as nitrogen-containing heteroaromatic compounds can also be used.

[0330] Specifically, metal complexes such as Alq3, tris(4-methyl-8-hydroxyquinoline)aluminum(III) (abbreviated as Almq3), bis(10-hydroxybenzo[h]-quinoline)beryllium(II) (abbreviated as BeBq2), BAlq, Zn(BOX)2, bis[2-(2-hydroxyphenyl)benzothiazole]zinc(II) (abbreviated as Zn(BTZ)2), 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated as PBD), 1,3-bis[5-(p-tert-butylphenyl)benzothiazole] 1,3,4-oxadiazol-2-yl]benzene (abbreviated as OXD-7), 3-(4'-tert-butylphenyl)-4-phenyl-5-(4"-biphenyl)-1,2,4-triazole (abbreviated as TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenyl)-1,2,4-triazole (abbreviated as p-EtTAZ), bathophenanthroline (abbreviated as Bphen), bathocuproin (abbreviated as BCP), 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviated as BzO S) and other heteroaromatic compounds, quinoxaline derivatives or dibenzoquinoxaline derivatives such as 2-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[4-(3,6-diphenyl-9H-carbazole-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II) and 6-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II).

[0331] In addition, polymer compounds such as poly(2,5-pyridinediyl) (abbreviation: PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviation: PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviation: PF-BPy) can also be used.

[0332] <Electron Injection Layer> The electron injection layer 1115 is a layer containing a substance with high electron injection properties. As the electron injection layer 1115, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), and lithium oxide (LiO x ) or other alkali metals, alkaline earth metals, or compounds of these metals. In addition, rare earth metal compounds such as erbium fluoride (ErF3) can be used. In addition, electron salts can also be used for the electron injection layer 1115. As electron salts, for example, substances that add electrons to a mixed oxide of calcium and aluminum at a high concentration can be cited. In addition, the substances that constitute the electron transport layer 1114 as described above can also be used.

[0333] In addition, a composite material formed by mixing an organic compound with an electron donor (donor) can also be used for the electron injection layer 1115. This composite material has excellent electron injection and electron transport properties because electrons are generated in the organic compound by the electron donor. In this case, the organic compound is preferably a material with excellent performance in transporting the generated electrons. Specifically, for example, an electron transport material (metal complex, heteroaromatic compound, etc.) for the electron transport layer 1114 as described above can be used. As an electron donor, any substance that exhibits electron donating properties to an organic compound can be used. Specifically, alkali metals, alkaline earth metals and rare earth metals are preferably used, and lithium, cesium, magnesium, calcium, erbium, ytterbium, etc. can be cited. In addition, alkali metal oxides or alkaline earth metal oxides are preferably used, and lithium oxide, calcium oxide, barium oxide, etc. can be cited. In addition, Lewis bases such as magnesium oxide can also be used. In addition, organic compounds such as tetrathiafulvalene (abbreviated as: TTF) can also be used.

[0334] <Charge Generation Layer> The charge generation layer 1109 may have a structure in which an electron acceptor (acceptor) is added to a hole transport material, or may have a structure in which an electron donor (donor) is added to an electron transport material. Alternatively, these two structures may be stacked. In addition, by using the above-mentioned materials to form the charge generation layer 1109, the increase in the driving voltage when the EL layer is stacked can be suppressed.

[0335] In the case where the charge generation layer 1109 has a structure in which an electron acceptor is added to a hole transport material, the material described in this embodiment can be used as a hole transport material. In addition, as an electron acceptor, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviated as: F4-TCNQ), chloranil, etc. can be cited. In addition, oxides of metals belonging to Groups 4 to 8 in the periodic table can be cited. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, rhenium oxide, etc. can be cited.

[0336] In the case where the charge generation layer 1109 has a structure in which an electron donor is added to an electron transport material, the material shown in this embodiment can be used as an electron transport material. In addition, as an electron donor, an alkali metal, an alkaline earth metal, a rare earth metal, or a metal belonging to Group 2 or Group 13 in the periodic table and their oxides or carbonates can be used. Specifically, lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium oxide, cesium carbonate, etc. are preferably used. In addition, organic compounds such as tetrathianaphthacene can also be used as electron donors.

[0337] In addition, when the light-emitting element shown in this embodiment is manufactured, a vacuum process such as evaporation or a solution process such as spin coating or inkjet can be used. As an evaporation method, a physical evaporation method (PVD method) or chemical vapor deposition method (CVD method) such as sputtering, ion plating, ion beam evaporation, molecular beam evaporation, vacuum evaporation can be used. In particular, a functional layer (hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer) and a charge generation layer included in the EL layer of the light-emitting element can be formed using evaporation (vacuum evaporation), coating (dip coating, dye coating, rod coating, spin coating, spray coating, etc.), printing (inkjet, screen printing (porcelain printing) method, offset printing (lithography) method, flexographic printing (relief printing) method, gravure printing, micro-contact printing, etc.) and other methods.

[0338] In addition, the materials of the functional layers (hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer and charge generation layer) constituting the EL layer of the light-emitting element shown in this embodiment are not limited thereto, and can be used in combination as long as the materials can satisfy the functions of each layer. As an example, polymer compounds (oligomers, dendrimers, polymers, etc.), medium molecular compounds (compounds between low molecules and polymers: molecular weight of 400 to 4000), inorganic compounds (quantum dot materials, etc.), etc. can be used. As quantum dot materials, colloidal quantum dot materials, alloy-type quantum dot materials, core-shell quantum dot materials, core-type quantum dot materials, etc. can be used.

[0339] This embodiment mode can be combined with other embodiment modes as appropriate.

[0340] (Implementation 4) In this embodiment, using FIG. 17A to FIG. 18F An electronic device according to one embodiment of the present invention will be described.

[0341] The electronic device of this embodiment includes a display device of one embodiment of the present invention in a display portion. The display device of one embodiment of the present invention can be easily enlarged. In addition, the display device of one embodiment of the present invention has high reliability and low power consumption. Therefore, the display device of one embodiment of the present invention can be used in the display portion of various electronic devices.

[0342] The display unit of the electronic device of this embodiment can display images with full HD, 4K2K, 8K4K, 16K8K or higher resolution, for example. In addition, the screen size of the display unit can be more than 20 inches, more than 30 inches, more than 50 inches, more than 60 inches or more than 70 inches diagonally.

[0343] Electronic devices include, for example, television sets, desktop or notebook personal computers, displays for computers, etc., digital signage, large-scale game consoles such as pinball machines, and other electronic devices with larger screens, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, portable information terminals, sound reproduction devices, and the like.

[0344] The electronic device of this embodiment can be assembled along the curved surface of the inner wall or outer wall of a house or a building, or the interior decoration or exterior decoration of a car.

[0345] The electronic device of this embodiment may also include an antenna. By receiving a signal through the antenna, an image or data can be displayed on the display unit. In addition, when the electronic device includes an antenna and a secondary battery, the antenna can be used for contactless power transmission.

[0346] The electronic device of this embodiment may also include a sensor (the sensor has the function of measuring the following factors: force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, electricity, radiation, flow, humidity, inclination, vibration, smell or infrared).

[0347] The electronic device of this embodiment may have various functions. For example, it may have the following functions: a function of displaying various information (static images, dynamic images, text images, etc.) on a display unit; a function of a touch panel; a function of displaying a calendar, date, or time, etc.; a function of executing various software (programs); a function of wireless communication; a function of reading programs or data stored in a storage medium; etc.

[0348] Fig.17A 100 shows an example of a television set. In a television set 7100, a display portion 7000 is incorporated in a housing 7101. Here, a structure in which the housing 7101 is supported by a stand 7103 is shown.

[0349] The display device of one embodiment of the present invention can be applied to the display portion 7000 .

[0350] The operation can be performed by using the operation switch provided in the frame 7101 or the remote control operation machine 7111 provided separately. Fig.17AThe television device 7100 shown in the figure can be operated. In addition, the display portion 7000 can be provided with a touch sensor, and the television device 7100 can be operated by touching the display portion 7000 with a finger or the like. In addition, the remote control unit 7111 can be provided with a display unit that displays data output from the remote control unit 7111. By using the operation keys or the touch panel provided in the remote control unit 7111, the channel and volume can be operated, and the image displayed on the display portion 7000 can be operated.

[0351] In addition, the television set 7100 has a receiver and a modem, etc. General television broadcasts can be received by using the receiver. Furthermore, the television set 7100 is connected to a wired or wireless communication network through a modem to perform one-way (from a sender to a receiver) or two-way (between a sender and a receiver or between receivers, etc.) information communication.

[0352] Fig. 17B The notebook personal computer 7200 includes a housing 7211 , a keyboard 7212 , a pointing device 7213 , an external connection port 7214 , and the like. A display portion 7000 is incorporated in the housing 7211 .

[0353] The display device of one embodiment of the present invention can be applied to the display portion 7000 .

[0354] Fig. 17C and Fig.17D An example of digital signage is shown.

[0355] Fig. 17C The digital signage 7300 shown includes a housing 7301, a display portion 7000, a speaker 7303, etc. In addition, an LED lamp, operation keys (including a power switch or an operation switch), a connection terminal, various sensors, a microphone, etc. may be included.

[0356] Fig.17D The digital signage 7400 is shown to be disposed on a cylindrical pillar 7401. The digital signage 7400 includes a display unit 7000 disposed along a curved surface of the pillar 7401.

[0357] exist Fig. 17C and Fig.17D In the embodiment of the present invention, a display device according to one embodiment of the present invention can be applied to the display portion 7000 .

[0358] The larger the display unit 7000 is, the more information can be provided at one time. The larger the display unit 7000 is, the easier it is to attract people's attention, for example, the advertising effect can be improved.

[0359] By using a touch panel for the display unit 7000, not only can a static image or a dynamic image be displayed on the display unit 7000, but the user can also intuitively operate it, which is preferred. In addition, when used for providing information such as route information or traffic information, the ease of use can be improved through intuitive operation.

[0360] like Fig. 17C and Fig.17D As shown, the digital signage 7300 or the digital signage 7400 can be linked with the information terminal device 7311 or the information terminal device 7411 such as a smartphone carried by the user preferably through wireless communication. For example, the advertising information displayed on the display unit 7000 can be displayed on the screen of the information terminal device 7311 or the information terminal device 7411. In addition, by operating the information terminal device 7311 or the information terminal device 7411, the display of the display unit 7000 can be switched.

[0361] In addition, the game can be executed on the digital signage 7300 or the digital signage 7400 using the screen of the information terminal device 7311 or the information terminal device 7411 as an operation unit (controller). Thus, an unspecified number of users can participate in the game at the same time and enjoy the game.

[0362] FIG. 18A to FIG. 18F The electronic device shown includes a frame 9000, a display portion 9001, a speaker 9003, an operation key 9005 (including a power switch or an operation switch), a connecting terminal 9006, a sensor 9007 (the sensor has the function of measuring the following factors: force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, electricity, radiation, flow, humidity, inclination, vibration, smell or infrared), a microphone 9008, etc.

[0363] FIG. 18A to FIG. 18F The electronic device shown has various functions. For example, it may have the following functions: a function of displaying various information (static images, dynamic images, text images, etc.) on a display unit; a function of a touch panel; a function of displaying a calendar, date, or time, etc.; a function of controlling processing by using various software (programs); a function of wireless communication; a function of reading out a program or data stored in a storage medium and processing it; etc. Note that the functions that an electronic device may have are not limited to the above functions, but may have various functions. An electronic device may include multiple display units. In addition, a camera or the like may be provided in an electronic device so that it has the following functions: a function of taking a static image or a dynamic image, and storing the taken image in a storage medium (an external storage medium or a storage medium built into a camera); a function of displaying the taken image on a display unit; etc.

[0364] Below, we explain in detail FIG. 18A to FIG. 18F Electronic equipment shown.

[0365] Fig.18A 9101 is a perspective view showing a portable information terminal 9101. The portable information terminal 9101 can be used as a smart phone, for example. Note that a speaker 9003, a connection terminal 9006, a sensor 9007, etc. can also be provided in the portable information terminal 9101. In addition, as the portable information terminal 9101, text or image information can be displayed on multiple surfaces. Fig.18A 9050. In addition, information 9051 indicated by a dotted rectangle may be displayed on another surface of display unit 9001. Examples of information 9051 include information indicating that an email, SNS (Social Networking Services) or phone call has been received; a title of the email or SNS; a sender's name of the email or SNS; a date; a time; a remaining battery level; and a display of the antenna receiving signal strength. Alternatively, icon 9050 may be displayed at a location where information 9051 is displayed.

[0366] Fig.18B 9102 is a three-dimensional diagram showing a portable information terminal 9102. The portable information terminal 9102 has a function of displaying information on three or more surfaces of the display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different surfaces. For example, when the portable information terminal 9102 is placed in a jacket pocket, the user can confirm the information 9053 displayed at a position viewed from above the portable information terminal 9102. The user can confirm the display without taking the portable information terminal 9102 out of the pocket, thereby being able to determine whether to answer the call.

[0367] Fig.18C 9001 is a perspective view showing a watch-type portable information terminal 9200. The portable information terminal 9200 can be used as a smart watch, for example. In addition, the display surface of the display unit 9001 is curved, and a display can be performed along the curved display surface. In addition, the portable information terminal 9200 can perform hands-free calls, for example, by communicating with a headset capable of wireless communication. In addition, by using the connection terminal 9006, the portable information terminal 9200 can perform data transmission or charging with other information terminals. Charging can also be performed by wireless power supply.

[0368] Fig.18D , Fig.18E and Fig.18F 9201 is a perspective view showing a foldable portable information terminal. Fig.18Dis a perspective view of the portable information terminal 9201 in an unfolded state. Fig.18F This is a three-dimensional image of the folded state. Fig.18E is from Fig.18D Status and Fig.18F The portable information terminal 9201 is easy to carry in the folded state, and has a large display area that is seamlessly spliced ​​in the unfolded state, so the display is easy to browse. 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 within a range of a curvature radius of 0.1 mm or more and 150 mm or less, for example.

[0369] This embodiment mode can be combined with other embodiment modes as appropriate. [Explanation of symbols]

[0370] CCMG: color conversion layer, CCMR: color conversion layer, C1: capacitor, C2: capacitor, C11: capacitor, C12: capacitor, DATA: image data, DATA_W: data, DATA_W1: data, DATA_W2: data, DL: wiring, DL1: wiring, DL11: wiring, DL12: wiring, DL13: wiring, DLW1: wiring, GL: wiring, GL1: wiring, GL2: wiring, GL3: wiring, GL11: wiring, GL12: wiring, GL13: wiring, MEM: memory circuit, M1: transistor, M2: transistor, M3: transistor, M4: transistor, M5: transistor, M11: transistor, M12: crystal tube, M13: transistor, ND1: node, ND2: node, ND11: node, ND12: node, ND13: node, PIX: pixel, V0: wiring, 10A: display device, 10B: display device, 10C: display device, 10D: display device, 11: display unit, 13: gate driver, 14: source driver, 15: display device, 71: display unit, 74: FPC, 78: drive circuit, 100: pixel, 101: pixel, 104: insulating layer, 107: partition wall, 110: light emitting element, 110B: light emitting element, 111: pixel electrode, 113: EL layer, 115: common electrode, 117: protective layer, 120: circuit, 121: space , 141: insulating layer, 150: circuit block, 171: transistor, 172: transistor, 173: capacitor, 175: transistor, 186: wiring, 187: power supply line, 189: common wiring, 190: wiring, 191: wiring, 201: conductive layer, 202: insulating layer, 203a: conductive layer, 203b: conductive layer, 204: semiconductor layer, 208: insulating layer, 211: insulating layer, 212: insulating layer, 213: insulating layer, 214a: channel formation region, 214b: low resistance region, 214c: LDD region, 220: transistor, 230: transistor, 301: transistor, 303: transistor, 306: connection portion, 307: wiring, 311: Gate insulating layer, 312: insulating layer, 313: insulating layer, 314: insulating layer, 315: insulating layer, 317: adhesive layer, 318: adhesive layer, 319: connector, 355: conductive layer, 361: substrate, 363: adhesive layer, 365: insulating layer, 367: insulating layer, 371: substrate, 1100B: pixel, 1100G: pixel, 1100R: pixel, 1100W: pixel, 1101: electrode, 1102: electrode, 1103B: EL layer, 1104G: color conversion layer, 1104R: color conversion layer, 1104W: color conversion layer, 1105B: light emitting element, 1106B: light, 1106G: light, 1106R: light, 1106W: light,1107: optical adjustment layer, 1109: charge generation layer, 1111: hole injection layer, 1112: hole transport layer, 1113: light emitting layer, 1114: electron transport layer, 1115: electron injection layer, 1123B: light emitting unit, 4000: molecular weight, 7000: display unit, 7100: television device, 7101: housing, 7103: stand, 7111: remote control unit, 7200: notebook personal computer, 7211: housing, 7212: keyboard, 7213: pointing device, 7214: external connection port, 7300: digital signage, 7301: housing, 73 03: speaker, 7311: information terminal device, 7400: digital signage, 7401: pillar, 7411: information terminal device, 9000: housing, 9001: display unit, 9003: speaker, 9005: operation key, 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, 9200: portable information terminal, 9201: portable information terminal,

Claims

1. A display device, comprising: a first pixel and a second pixel; a first wiring configured to supply a first signal; as well as a second wiring configured to supply a second signal; Each of the first pixel and the second pixel includes a light emitting element, a first transistor, a second transistor, a third transistor, a fourth transistor, a first capacitor and a second capacitor. The first wiring and one electrode of the first capacitor are electrically connected to each other through a channel formation region of the first transistor. The second wiring and the other electrode of the first capacitor are electrically connected to each other through a channel formation region of the second transistor, The other electrode of the first capacitor and one electrode of the second capacitor are electrically connected to each other, The other electrode of the second capacitor and one of the source and the drain of the fourth transistor are electrically connected to each other, The one electrode of the first capacitor and the gate of the third transistor are electrically connected to each other, One of the source and the drain of the third transistor and the light emitting element are electrically connected to each other, The light emitting element includes a first light emitting unit and a second light emitting unit. Each of the first light emitting unit and the second light emitting unit emits blue light, The light emitting element and the color conversion layer of the first pixel overlap each other, And, the color conversion layer is configured to convert light emitted by the light emitting element of the first pixel into light having a longer wavelength.

2. A display device, comprising: a first pixel and a second pixel; a first wiring configured to supply a first signal; as well as a second wiring configured to supply a second signal; Each of the first pixel and the second pixel includes a light emitting element, a first transistor, a second transistor, a third transistor, a fourth transistor, a first capacitor and a second capacitor. The first wiring and one electrode of the first capacitor are electrically connected to each other through a channel formation region of the first transistor. The second wiring and the other electrode of the first capacitor are electrically connected to each other through a channel formation region of the second transistor, The other electrode of the first capacitor and one electrode of the second capacitor are electrically connected to each other, The other electrode of the second capacitor and one of the source and the drain of the fourth transistor are electrically connected to each other, The one electrode of the first capacitor and the gate of the third transistor are electrically connected to each other, One of the source and the drain of the third transistor and the light emitting element are electrically connected to each other, The light emitting element includes a first light emitting unit and a second light emitting unit. One of the first light emitting unit and the second light emitting unit emits blue light, The luminescent material of the first luminescent unit and the luminescent material of the second luminescent unit are different from each other, The light emitting element and the color conversion layer of the first pixel overlap each other, And, the color conversion layer is configured to convert light emitted by the light emitting element of the first pixel into light having a longer wavelength.

3. A display device, comprising: a first pixel and a second pixel; a first wiring configured to supply a first signal; as well as a second wiring configured to supply a second signal; Each of the first pixel and the second pixel includes a light emitting element, a first transistor, a second transistor, a third transistor, a fourth transistor, a first capacitor and a second capacitor. The first wiring and one electrode of the first capacitor are electrically connected to each other through a channel formation region of the first transistor. The second wiring and the other electrode of the first capacitor are electrically connected to each other through a channel formation region of the second transistor, The other electrode of the first capacitor and one electrode of the second capacitor are electrically connected to each other, The other electrode of the second capacitor and one of the source and the drain of the fourth transistor are electrically connected to each other, The one electrode of the first capacitor and the gate of the third transistor are electrically connected to each other, One of the source and the drain of the third transistor and the light emitting element are electrically connected to each other, The light emitting element includes a first light emitting unit, a second light emitting unit and a third light emitting unit. At least one of the first light emitting unit, the second light emitting unit and the third light emitting unit emits blue light, Two of the first light-emitting unit, the second light-emitting unit and the third light-emitting unit emit fluorescent light, The other one of the first light-emitting unit, the second light-emitting unit and the third light-emitting unit emits phosphorescence, The light emitting element and the color conversion layer of the first pixel overlap each other, And, the color conversion layer is configured to convert light emitted by the light emitting element of the first pixel into light having a longer wavelength.

4. The display device according to any one of claims 1 to 3, Wherein the color conversion layer comprises quantum dots.

5. The display device according to any one of claims 1 to 3, Each of the first transistor and the second transistor includes a metal oxide in the channel formation region.

Images