Light-emitting element

Abstract

To provide a display device having a wide view angle, with which display over a wide color gamut is possible.SOLUTION: Provided is a display device comprising a first luminous element, a second luminous element, and a third luminous element. Each luminous element includes a pair of electrodes and a luminous layer. One of the pair of electrodes has a reflection electrode, and the other has a semi-permeable, semi-reflection electrode. The luminous layers that each luminous element has are mutually different layers. The first peak wavelength of emission spectrum of the first luminous element is 400 nm to 480 nm inclusive. The second peak wavelength of emission spectrum of the second luminous element is 580 nm to 700 nm inclusive. The third peak wavelength of emission spectrum of the third luminous element lies between the first peak wavelength and the second peak wavelength. The distance between the pair of electrodes is longest for the first luminous element and second longest for the second luminous element.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Note that one embodiment of the present invention is not limited to the above technical field. Examples of such devices include semiconductor devices, display devices, light-emitting devices, electronic devices, lighting devices, and input / output devices (for example, touch panel, etc.), their driving method, or their manufacturing method are given as examples. This can be done. [Background technology]

[0003] In recent years, display devices are expected to be used in a variety of applications. For example, the use of large display devices Examples include home television equipment (also called televisions or television receivers), digital Digital Signage, PID (Public Identification Number) c Information Display) and the like. The larger the display area, the more information can be provided at once. It is highly noticeable and is expected to increase the effectiveness of advertising, for example.

[0004] As a display device, for example, a light-emitting device having a light-emitting element has been developed. Utilizing the electroluminescence (EL) phenomenon The light-emitting element (also called EL element) is easy to make thin and lightweight, and it responds quickly to input signals. It has the characteristics of being able to respond to the display device, being able to be driven by a low-voltage DC power supply, etc. It is used.

[0005] In addition, organic EL elements are being considered for application to flexible devices. Document 1 discloses a flexible light-emitting device to which an organic EL element is applied. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-197522 Summary of the Invention [Problem to be solved by the invention]

[0007] Due to their various uses, display devices are not only viewed from the front but also from oblique angles. High visibility is required even when the display device is viewed from an oblique direction. It is desirable that the display when viewing from the front of the display device be as close to the actual display as possible. .

[0008] An object of one embodiment of the present invention is to provide a display device with a wide viewing angle. An object of one embodiment is to provide a display device capable of displaying a wide color gamut.

[0009] Note that the description of these problems does not preclude the existence of other problems. It is not necessary to solve all of these problems. From the description of the section, it is possible to extract other issues. [Means for solving the problem]

[0010] One embodiment of the present invention is a display having a first light-emitting element, a second light-emitting element, and a third light-emitting element. The first light emitting element, the second light emitting element, and the third light emitting element each comprise a pair of light emitting elements. and a light-emitting layer between the pair of electrodes. One of the pair of electrodes has a reflective electrode. The other of the pair of electrodes is a semi-transmissive / semi-reflective electrode. The light-emitting layers of the first and third light-emitting elements are different from each other. The first peak wavelength of the optical spectrum is 400 nm or more and 480 nm or less. The second peak wavelength of the emission spectrum of the element is 580 nm or more and 700 nm or less. The third peak wavelength of the emission spectrum of the third light-emitting element is the wavelength of the first peak and the second peak. The wavelength is between the wavelengths. The first light-emitting element is thicker than the second light-emitting element. is preferably thicker than the third light emitting element. The distance between the electrodes is longer than the distance between the pair of electrodes of the second light-emitting element. The distance between the pair of electrodes of the first light-emitting element is longer than the distance between the pair of electrodes of the third light-emitting element. It is preferable that

[0011] The difference between the thickness of the first light-emitting element and the thickness of the second light-emitting element is 40 nm or more and 90 nm or less. Alternatively, it is preferable that the distance between the pair of electrodes of the first light-emitting element and the distance between the pair of electrodes of the second light-emitting element are The difference between the distance between a pair of electrodes of the element is preferably 40 nm or more and 90 nm or less. It's nice.

[0012] The first light-emitting element, the second light-emitting element, and the third light-emitting element each have a pair of electrodes and It is preferable that the first light-emitting element has a hole transport layer. In this case, the hole transport layer of the first light-emitting element is It is preferable that the hole transport layer is thicker than the hole transport layer of the second light emitting element, and the hole transport layer of the first light emitting element The hole transport layer is preferably thicker than the hole transport layer of the third light-emitting element.

[0013] The first light-emitting element, the second light-emitting element, and the third light-emitting element each include a reflective electrode and a light-emitting layer. It is preferable that a transparent electrode is provided between the first light-emitting element and the second light-emitting element. The transparent electrode of the second light-emitting element is preferably thicker than the transparent electrode of the first light-emitting element. The transparent electrode of the first light-emitting element is preferably thicker than the transparent electrode of the third light-emitting element. The optical element, the second light-emitting element, and the third light-emitting element each have a transparent electrode and a light-emitting layer therebetween. It is preferable that the first light-emitting element and the second light-emitting element have a hole injection layer and a hole transport layer. The hole injection layer of the light-emitting element and the third light-emitting element is preferably a common layer. Similarly, the hole transport layers of the first light-emitting element, the second light-emitting element, and the third light-emitting element each have: It is preferable that the hole injection layer and the hole transport layer are a common layer. It is preferable that the first light emitting element, the second light emitting element, and the third light emitting element share the same light emitting element.

[0014] The first light-emitting element, the second light-emitting element, and the third light-emitting element each have a pair of electrodes and The first light-emitting element, the second light-emitting element, and the third light-emitting element preferably have an electron transport layer. The electron transport layer of the element is preferably a common layer. It is preferable that the first light emitting element, the second light emitting element, and the third light emitting element share the same light emitting element. stomach.

[0015] In the CIE1976 chromaticity coordinates (u'v' chromaticity coordinates), the front of the light emitted from the second light-emitting element The chromaticity difference Δu'v' between the chromaticity in the direction and the chromaticity in the direction tilted 60° from the front is 0.05 or less. Similarly, it is preferable that the first light-emitting element or The chromaticity difference between the chromaticity of the light emitted from the third light-emitting element in the front direction and the chromaticity in the direction tilted 60 degrees from the front direction It is preferable that Δu'v' is 0.05 or less. The inclination is not limited to 60°. For example, For example, the same is true for angles of 30°, 40°, 50°, 70°, or 80°. This is preferable.

[0016] When white is displayed using the first light-emitting element, the second light-emitting element, and the third light-emitting element, In the CIE1976 chromaticity coordinates, the chromaticity in the front direction and the chromaticity in the direction tilted 60 degrees from the front The chromaticity difference Δu'v' is preferably 0.05 or less. The inclination is not limited to 60°. The same applies to angles of, for example, 30°, 40°, 50°, 70°, or 80°. In this specification, white light refers to, for example, a standard illuminant D6 It can display a chromaticity of 5, and the brightness at that time is 10cd / m 2 More than 300cd / m 2 The following is preferred:

[0017] The relative luminance in a direction tilted 30° from the front relative luminance is defined as the first relative luminance, and the front luminance is defined as the second relative luminance. When the relative luminance in the direction tilted 60 degrees from the front is the second relative luminance, The first relative luminance of the element is higher than the first relative luminance of the first light-emitting element. and the second relative luminance of the second light-emitting element is preferably It is preferable that the relative luminance is higher than the relative luminance.

[0018] The light-emitting layers of the first light-emitting element, the second light-emitting element, and the third light-emitting element are separated from each other. It is preferable that

[0019] One aspect of the present invention is a display device having any of the above configurations, board (Flexible printed circuit, hereafter referred to as FPC) or is equipped with a connector such as TCP (Tape Carrier Package) Display module, or COG (Chip On Glass) or COF (C Display modules with ICs mounted using the "Hip On Film" method, etc. It is a rule.

[0020] One aspect of the present invention is a display device including the above-described display module, an antenna, a battery, a housing, a camera, a speaker, and the like. The electronic device has at least one of a speaker, a microphone, and an operation button. [Effects of the Invention]

[0021] According to one embodiment of the present invention, a display device with a wide viewing angle can be provided. A display device capable of displaying in the color gamut can be provided.

[0022] The description of these effects does not preclude the existence of other effects. However, it is not necessary to have all of these effects. , it is possible to extract effects other than these. [Brief explanation of the drawings]

[0023] [Figure 1] 1A and 1B are diagrams illustrating examples of light-emitting elements included in a display device. [Figure 2] 1A and 1B are diagrams illustrating examples of light-emitting elements included in a display device. [Figure 3] 1A to 1C are diagrams showing an example of a method for manufacturing an optical adjustment layer included in a display device. [Figure 4] 1A and 1B are diagrams illustrating examples of light-emitting elements included in a display device. [Figure 5]Chromaticity diagram illustrating the chromaticity range of a display device. [Figure 6] FIG. 1 illustrates an example of a display device. [Figure 7] FIG. 1 illustrates an example of a display device. [Figure 8] FIG. 1 illustrates an example of a display device. [Figure 9] 1A and 1B are diagrams illustrating examples of electronic devices. [Figure 10] 1A and 1B are diagrams illustrating examples of electronic devices. [Figure 11] 1A and 1B illustrate a light-emitting element and a comparative light-emitting element of Example 1. [Figure 12] FIG. 2 is a diagram showing the CIE1931 chromaticity coordinates of the light-emitting element of Example 1. [Figure 13] FIG. 2 is a diagram showing the CIE1976 chromaticity coordinates of the light-emitting element of Example 1. [Figure 14] FIG. 1 is a graph showing the CIE1931 chromaticity coordinates of a comparative light-emitting element according to Example 1. [Figure 15] FIG. 2 is a graph showing the CIE1976 chromaticity coordinates of the comparative light-emitting element of Example 1. [Figure 16] FIG. 10 is a graph showing the viewing angle dependence of the luminance of the light-emitting element of Example 1. [Figure 17] 10A and 10B are graphs illustrating the viewing angle dependence of the chromaticity of the light-emitting element of Example 1. [Figure 18] FIG. 10 is a graph showing the viewing angle dependence of the luminance of the comparative light-emitting element in Example 1. [Figure 19] FIG. 10 is a graph showing the viewing angle dependency of the chromaticity of the comparative light-emitting element of Example 1. [Figure 20] FIG. 10 is a graph showing current-voltage characteristics of a light-emitting element. [Figure 21] 10A and 10B show the results of a reliability test of a light-emitting element. [Figure 22] Evaluation results of power consumption, color gamut, and color shift of light-emitting elements. DETAILED DESCRIPTION OF THE INVENTION

[0024] The embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description. The present invention is not limited to the above embodiments, and various changes and modifications may be made in the form and details thereof without departing from the spirit and scope of the present invention. It will be readily understood by those skilled in the art that the present invention can be achieved by the following embodiments. It should not be construed as being limited to the contents described.

[0025] In the configuration of the invention described below, the same parts or parts having similar functions are The same reference numerals are used in common between different drawings, and repeated explanations thereof will be omitted. When referring to a function, the hatch pattern may be the same and no particular symbol may be assigned.

[0026] In addition, the position, size, range, etc. of each component shown in the drawings are not necessarily the same as in reality for ease of understanding. Therefore, the disclosed invention may not necessarily represent the position, size, range, etc. Furthermore, the present invention is not limited to the position, size, range, etc. disclosed in the drawings.

[0027] The words "film" and "layer" may be used interchangeably depending on the situation. For example, the term "conductive layer" can be replaced with "conductive film." Alternatively, for example, the term "insulating film" can be changed to The term can be changed to "insulating layer."

[0028] (Embodiment 1) In this embodiment, a display device according to one embodiment of the present invention will be described with reference to FIGS.

[0029] The display device of this embodiment has a first light-emitting element, a second light-emitting element, and a third light-emitting element. The first light emitting element, the second light emitting element, and the third light emitting element each have a pair of electrodes and a light-emitting layer between the pair of electrodes.

[0030] The first light-emitting element, the second light-emitting element, and the third light-emitting element each include a microcavity (microcavity). One of the pair of electrodes of each light-emitting element has a reflective electrode. The other electrode has a semi-transmissive and semi-reflective electrode. The optical distance between the pair of electrodes is determined by the light-emitting layer. The wavelength of the light to be transmitted is mλ / 2 (where m is a natural number) or close to it. It is preferable to adjust

[0031] The display device of this embodiment uses a color-coded coloring method. The light-emitting layers of the light-emitting element, the second light-emitting element, and the third light-emitting element are different layers. The light-emitting layers of the first light-emitting element, the second light-emitting element, and the third light-emitting element are It is preferable that the light emitting elements are separated. The light-emitting layers may have overlapping portions. The term "separated" does not necessarily mean that the light-emitting layers are spatially separated, but rather that the light-emitting layers are electrically separated from each other. This includes cases where the equipment is physically isolated.

[0032] The first peak wavelength of the emission spectrum of the first light-emitting element is 400 nm or more and 480 nm or less. The first light-emitting element is, for example, a light-emitting element that emits blue light.

[0033] The second peak wavelength of the emission spectrum of the second light-emitting element is 580 nm or more and 700 nm or less. The second light-emitting element is, for example, a light-emitting element that emits red light.

[0034] The third peak wavelength of the emission spectrum of the third light-emitting element is a wavelength that is smaller than the first peak wavelength and the second peak wavelength. The third light-emitting element may be, for example, a light-emitting element that emits green light, or is a light-emitting element that emits yellow light.

[0035] The display device of this embodiment is characterized by the thickness of each light-emitting element. The element is thicker than the second light-emitting element, which is thicker than the third light-emitting element. Alternatively, the distance between the pair of electrodes of the first light-emitting element is set to be equal to the distance between the pair of electrodes of the second light-emitting element. The distance between the pair of electrodes of the second light emitting element is longer than the distance between the electrodes of the third light emitting element. By adopting such a configuration, the display device can be viewed obliquely. Color shift is unlikely to occur when viewing from the opposite direction and when viewing from the front of the display device. Therefore, a display device with a wide viewing angle can be realized.

[0036] For example, in the first light-emitting element, the second light-emitting element, and the third light-emitting element, the optical If the distance is the same multiple (i.e., m is the same for each light-emitting element in the above mλ / 2), the angle The attenuation of luminance due to the light emitted from the second and third light-emitting elements, which have higher visibility, is greater than that of the first light-emitting element. Since the size of the display element is larger than that of the optical element, the viewing angle dependency of the white chromaticity is large. In this configuration, the second and third light-emitting elements have a lower luminance than the first light-emitting element. This reduces the viewing angle dependency of white chromaticity. Specifically, the optical distance between the pair of electrodes of the first light-emitting element is one wavelength (m=2), and The optical distance between the pair of electrodes of the second light emitting element and the third light emitting element is 1 / 2 wavelength (m=1). It is preferable to do so.

[0037] In the CIE1976 chromaticity coordinates, the chromaticity of the light emitted from each light-emitting element in the front direction and in the oblique direction (positive The chromaticity difference Δu'v' between the chromaticity of the direction in which the absolute value of the tilt from the plane is greater than 0° and less than 90° is preferably 0.05 or less. Chromaticity and tilted at an angle of 30° to 60° (preferably 30° to 80°) from the front The chromaticity difference Δu'v' from the chromaticity of the other direction is preferably 0.05 or less.

[0038] When white is displayed using the first light-emitting element, the second light-emitting element, and the third light-emitting element, Chromaticity in the front direction and oblique direction (absolute value of tilt from the front) in CIE1976 chromaticity coordinates The chromaticity difference Δu'v' between the chromaticity of the object (the direction of the object is greater than 0° and less than 90°) and the chromaticity of the object (the direction of the object is greater than 0° and less than 90°) is 0.05 or less. Specifically, it is preferable that the chromaticity in the front direction and the angle from the front direction be 30° or more and 60° or less (more preferably The chromaticity difference Δu'v' with the chromaticity in the tilted direction is preferably 0.05 It is preferable that:

[0039] The relative luminance in a direction tilted 30° from the front relative luminance is defined as the first relative luminance, and the front luminance is defined as the second relative luminance. When the relative luminance in the direction tilted 60 degrees from the front is the second relative luminance, The first relative luminance of the element is higher than the first relative luminance of the first light-emitting element. and the second relative luminance of the second light-emitting element is preferably It is preferable that the relative luminance is higher than the relative luminance.

[0040] As the viewing angle of the display device changes, the relative luminance of the first light-emitting element and the relative luminance of the second light-emitting element change. If the magnitude relationship with respect to luminance is reversed, the chromaticity of white may change significantly depending on the viewing angle. Therefore, the angle should be between 30° and 60° (more preferably between 30° and 80°) from the front. (hereinafter) the relative luminance of the first light-emitting element and the relative luminance of the second light-emitting element in the tilted direction It is preferable that the magnitude relationship does not change. The same applies to the second light emitting element and the third light emitting element.

[0041] The display device of this embodiment has a small viewing angle dependency, and the display device can be viewed from an oblique direction. There is little change in contrast or chromaticity depending on the angle. The display is highly visible not only when viewed from above but also when viewed from an oblique angle. For example, a plurality of people can simultaneously observe the display device of this embodiment mode from various angles. The information displayed on the display device can be recognized by the user. Even when the display is viewed in a bent state, high visibility can be obtained. The display device of this embodiment is a display unit for a portable electronic device, a display unit for a personal electronic device, a large-screen display unit, etc. It can be used for a variety of purposes.

[0042] The display device is configured to express one color using three sub-pixels: R (red), G (green), and B (blue). A configuration in which one color is expressed using four sub-pixels of R, G, B, and W (white), or R, G, B, A configuration in which one color is expressed by four sub-pixels of Y (yellow), Y (yellow), and Y (yellow) can be applied. , colors other than RGBWY (for example, cyan or magenta) may be used.

[0043] Hereinafter, the display device of this embodiment and a light-emitting element included in the display device will be described in more detail. We will explain this in more detail.

[0044] <Configuration example 1 of light-emitting element> Using Figures 1(A) to (C), a display device with a configuration in which one color is expressed by three sub-pixels of RGB colors is shown. The light emitting element of the device will be described.

[0045] FIG. 1(A) shows a light emitting element 115R that emits red light 116R and a light emitting element 116G that emits green light. 10B, and a light emitting element 115G that emits blue light 116B.

[0046] The emission spectrum of the light emitting element 115B has a first wavelength in the range of 400 nm to 480 nm. The emission spectrum of the light emitting element 115R has a peak in the wavelength range of 580 nm to 700 nm. The emission spectrum of the light-emitting element 115G has a first peak in the range of 1000 nm or less. The third peak is at a wavelength longer than the first peak and shorter than the second peak.

[0047] Light emitting element 115B is thicker than light emitting element 115R. Thicker than 5G.

[0048] The difference in thickness between the light emitting element 115R and the light emitting element 115B is 40 nm or more and 90 nm or less. It is preferable that the thickness is 40 nm or more and 75 nm or less. The smaller the difference in thickness of the elements, the better the chromaticity of the light emitted by the two elements.

[0049] FIG. 1(B) shows a configuration example of each light-emitting element. Each light-emitting element has an EL layer between a pair of electrodes. The light emitting element 115R has an EL layer 113R between a first electrode 111 and a second electrode 112. The light-emitting element 115G has an EL layer 113 between a first electrode 111 and a second electrode 112. The light-emitting element 115B has an EL layer 115B between the first electrode 111 and the second electrode 112. It has 13B.

[0050] The first electrode 111 functions as an anode, and the second electrode 112 functions as a cathode.

[0051] A reflective electrode is used for the first electrode 111, and a semi-transparent and semi-reflective electrode is used for the second electrode 112. By using a microcavity structure, the light emitted from the EL layer is shared between both electrodes. This can vibrate the second electrode 112 and intensify the light that is transmitted through and emitted from the second electrode 112.

[0052] In this configuration example, the EL layer emits light toward the second electrode 112. A configuration in which the EL layer emits light toward the first electrode 111 side can also be applied. A reflective electrode is used for the second electrode 112, and a semi-transparent and semi-reflective electrode is used for the first electrode 111. This allows light to be emitted to the first electrode 111 side.

[0053] The materials and film thicknesses of the pair of electrodes of the three light-emitting elements shown in FIG. 1(B) are the same. This makes it possible to reduce the manufacturing cost of the display device and simplify the manufacturing process.

[0054] In FIG. 1B, the distance between a pair of electrodes of each light-emitting element corresponds to the thickness of the EL layer. The EL layer 113B is thicker than the EL layer 113R. The EL layer 113R is thicker than the EL layer 113G. Thicker than.

[0055] The difference in thickness between the EL layer 113R and the EL layer 113B is 40 nm or more and 90 nm or less. The thickness of the two EL layers is preferably 40 nm or more and 75 nm or less. The smaller the difference in thickness between the two elements, the better the chromaticity of the light emitted by the two elements.

[0056] The EL layer has a light-emitting layer containing a light-emitting substance, and emits fluorescent or phosphorescent light that exhibits a desired emission color. A structure capable of obtaining light is applied. A laminated structure can be applied to the EL layer.

[0057] The EL layer is formed with a different structure for each color. When the EL layer has a laminated structure, At least one layer included in the EL layer is formed of a different film for each of the light-emitting elements of multiple colors. When the EL layer has a laminated structure, at least one layer included in the EL layer is common to the light-emitting elements of multiple colors. It may be a layer of

[0058] By forming the EL layer with a different composition for each color, light-emitting elements can be produced with the appropriate thickness for each color. This makes it easier to

[0059] In the light emitting element 115R, the optical distance between the first electrode 111 and the second electrode 112 is The thickness of the EL layer 113R is adjusted so as to obtain an optical distance that intensifies the light. In 15G, the optical distance between the first electrode 111 and the second electrode 112 enhances green light emission. The thickness of the EL layer 113G is adjusted so as to achieve the optical path length. In this case, the optical distance between the first electrode 111 and the second electrode 112 is set to an optical distance that enhances blue light emission. The thickness of the EL layer 113B is adjusted so that

[0060] Specifically, the wavelength λ of the light obtained from the light emitting layer is Adjust so that the optical distance between 112 is mλ / 2 (where m is a natural number) or close to it. It is preferable to do so.

[0061] Here, a specific metal film (for example, a metal film containing a noble metal such as silver) is used as the reflective electrode. When used, surface plasmon resonance (SPR) This can cause a decrease in light extraction efficiency due to the influence of the surface of the metal film. At or near the plasmon resonance point, light resonates with the plasmon vibration inherent to the metal, and the wavelength corresponding to this vibration is generated. This is because the optical distance between the reflective electrode and the light-emitting region of the light-emitting layer is Therefore, in a device where the wavelength λ of light obtained from the light-emitting layer is the shortest, In a blue light emitting device using a metal film containing silver as a reflective electrode, the following configuration is applied. Specifically, in FIG. 2(A), the first electrode 111 to the light-emitting layer 123B The optical distance to the area where the desired light is obtained (light emitting area) is (2m'+1)λ / 4 (where , m' is a natural number) or its vicinity. The light-emitting region refers to a region in the light-emitting layer where holes and electrons recombine.

[0062] By performing such optical adjustment, the spectrum of a specific monochromatic light obtained from the light-emitting layer can be adjusted. It is possible to narrow the line width and obtain light emission with good color purity. This suppresses the deterioration and reduces the power consumption of the display device.

[0063] Strictly speaking, the optical distance between the first electrode 111 and the second electrode 112 is The product of the distance from the reflective area in 111 to the reflective area in the second electrode 112 and the refractive index However, it is difficult to strictly determine the reflective areas of the first electrode 111 and the second electrode 112. Therefore, it is difficult to determine the arbitrary positions of the first electrode 111 and the second electrode 112. is assumed to be a reflection region, the above-mentioned effect can be sufficiently obtained.

[0064] Similarly, the optical distance between the first electrode 111 and the light-emitting region is, strictly speaking, It is expressed as the product of the refractive index and the distance from the reflective area to the light-emitting area in the light-emitting layer. It is difficult to precisely determine the reflective area of ​​the electrode and the luminescent area of ​​the luminescent layer. Therefore, any position on the first electrode 111 can be set as a reflective region, and any position on the light-emitting layer can be set as a reflective region. The above-mentioned effect can be sufficiently obtained by assuming it to be a light-emitting region.

[0065] For example, the light emitting element 115R and the light emitting element 115G have an optical distance between the electrodes that is 1 / 2 wavelength. The light emitting element 115B is adjusted so that the optical distance between the electrodes is one wavelength. It is preferable that:

[0066] FIG. 1(C) shows an example of a configuration of each light-emitting element that is different from that shown in FIG. 1(B). The optical element has the same structure as that shown in FIG. 1(B) in that it has an optical adjustment layer between the first electrode and the EL layer. The light emitting element 115R has an optical adjustment layer between the first electrode 111 and the EL layer 113R. The light-emitting element 115G has an optical element between the first electrode 111 and the EL layer 113G. The light-emitting element 115B has an adjustment layer 110G. The light-emitting element 115B has an adjustment layer 110G between the first electrode 111 and the EL layer 113B. The optical adjustment layer 110B is provided therein.

[0067] In FIG. 1C, the distance between a pair of electrodes of each light-emitting element is determined by the thickness of the EL layer and the optical modulation. The sum of the thickness of the EL layer 113B and the thickness of the optical adjustment layer 110B. is greater than the sum of the thickness of the EL layer 113R and the thickness of the optical adjustment layer 110R. The sum of the thickness of the EL layer 113R and the thickness of the optical adjustment layer 110R is the sum of the thickness of the EL layer 113G and the thickness of the optical adjustment layer 110R. The sum of the thickness is greater than 10G.

[0068] The sum of the thickness of the EL layer 113B and the thickness of the optical adjustment layer 110B, the thickness of the EL layer 113R, and The difference from the sum of the thicknesses of the optical adjustment layers 110R is preferably 40 nm or more and 90 nm or less. The smaller the difference, the more preferable it is to have a difference between the two elements. The chromaticity of the light emitted from the child becomes good.

[0069] Optical adjustment can be performed by controlling the film thickness of the EL layer and the optical adjustment layer.

[0070] The optical adjustment layer can be made of a conductive film that transmits visible light (transparent conductive film).

[0071] Next, the EL layer of the light-emitting element will be described in more detail. The material and manufacturing method thereof will be described in detail in Embodiment 2.

[0072] <EL layer configuration example 1> FIG. 2(A) shows an example of the configuration of the EL layer of the three light-emitting elements shown in FIG. 1(B). It consists of several functional layers.

[0073] The EL layer 113R includes a hole injection layer 121, a hole transport layer 122R, a light emitting layer 123R, and an electron transport layer 124R. layer 124 and an electron injection layer 125 .

[0074] The EL layer 113G includes a hole injection layer 121, a hole transport layer 122G, a light-emitting layer 123G, and an electron transport layer 124G. layer 124 and an electron injection layer 125 .

[0075] The EL layer 113B includes a hole injection layer 121, a hole transport layer 122B, a light-emitting layer 123B, and an electron transport layer 124B. layer 124 and an electron injection layer 125 .

[0076] The more common functional layers there are for the light-emitting elements of each color, the more cost-effective it becomes to manufacture the EL layer and the easier it becomes to manufacture the light-emitting element. In the structure shown in FIG. 2A, the hole injection layer 121, the electron transport layer 124, and The light-emitting layer and the electron injection layer 125 are provided in common to the light-emitting elements of each color. By changing the thickness of the hole transport layer for each color, optical adjustment can be performed. It is preferable that the hole transport layer 22R and the hole transport layer 122G are formed of the same material and have the same thickness.

[0077] In FIG. 2(A), the hole transport layer 122B is thicker than the hole transport layer 122R. ), the hole transport layer 122B is thicker than the hole transport layer 122G.

[0078] <EL layer configuration example 2> FIG. 2B shows an example of the structure of the EL layer of the three light-emitting elements shown in FIG. 1C.

[0079] The EL layer 113R includes a hole injection layer 121, a hole transport layer 122, a light-emitting layer 123R, and an electron transport layer 124 and an electron injection layer 125.

[0080] The EL layer 113G includes a hole injection layer 121, a hole transport layer 122, a light-emitting layer 123G, and an electron transport layer 124 and an electron injection layer 125.

[0081] The EL layer 113B includes a hole injection layer 121, a hole transport layer 122, a light-emitting layer 123B, and an electron transport layer 124 and an electron injection layer 125.

[0082] In the structure shown in FIG. 2B, the hole injection layer 121, the electron transport layer 124, and the electron injection layer 12 In addition to the layer 5, a hole transport layer 122 is also provided in common to the light-emitting elements of each color. By changing the film thickness of the adjustment layer depending on the color, optical adjustment can be performed.

[0083] Here, the thickness of the optical adjustment layer 110R and the optical adjustment layer 110G shown in FIG. 2(B) is approximately the same. It is preferable that the thicknesses of the optical adjustment layer 110R and the optical adjustment layer 110G are made uniform. The optical adjustment layer 110R and the optical adjustment layer 110G can be formed on the light emitting layer 110R. The number of steps for fabricating the element can be reduced.

[0084] The optical adjustment layer is formed by exposure using a multi-tone mask (half-tone mask, gray-tone mask, etc.). It is preferable to form the EL layer by using optical technology. In addition, by changing the film thickness of the optical adjustment layer depending on the color, The cost of manufacturing light-emitting elements is lower than when multiple functional layers of the EL layer are painted separately. It may be possible to reduce the cost and simplify the manufacturing process.

[0085] An example of manufacturing an optical adjustment layer will be described with reference to FIG.

[0086] First, a conductive film 111a that will become the first electrode 111 is formed, and then a transparent conductive film 111b that will become the optical adjustment layer is formed. 10 is formed, and a multi-tone mask is used to form resist films with different thicknesses for each color. Specifically, a resist film is formed on the area where the optical adjustment layer 110R and the optical adjustment layer 110G are to be formed. 118R and the resist film 118G are formed to a first thickness, and the optical adjustment layer 110B The resist film 118B is formed on the area where the resist film 118B is to be formed so as to have a second thickness that is thicker than the first thickness. (Figure 3(A)).

[0087] Next, etching is performed to remove the first electrode 111, the optical adjustment layer 110R, and the optical adjustment layer 110R. At this point, the optical adjustment layer 10G and the optical adjustment layer 110B are formed (FIG. 3(B)). The thicknesses of the optical adjustment layer 10R, the optical adjustment layer 110G, and the optical adjustment layer 110B are approximately the same.

[0088] Next, the resist film 118R and the resist film 118R are removed by ashing using oxygen plasma or the like. 3C, the resist film 118G is removed. becomes thinner by approximately the first thickness (FIG. 3(C)).

[0089] Next, etching is performed to reduce the thickness of the optical adjustment layer 110R and the thickness of the optical adjustment layer 110G. At this time, a resist film 118 is left on the optical adjustment layer 110B. Since B remains, the optical adjustment layer 110B is not etched, and the optical adjustment layer 110R and the optical The thickness of the optical adjustment layer 110G remains greater than that of the optical adjustment layer 110G.

[0090] Then, the resist film 118B is removed. As a result, the photoresist film 118B is formed on the first electrodes 111 of each color. An optical adjustment layer can be formed.

[0091] <Configuration example 2 of light-emitting element> Using Figures 4(A) to (C), a display with a configuration that expresses one color using four sub-pixels of RGBY The light emitting element included in the device will be described.

[0092] FIG. 4A shows a light emitting element 115R that emits red light 116R and a light emitting element 116G that emits green light. light-emitting element 115G emitting blue light 116B, light-emitting element 115B emitting yellow light 116C, and light-emitting element 115G emitting blue light 116D. 116Y, which represents light emitting element 115Y.

[0093] The emission spectrum of the light emitting element 115B has a first wavelength in the range of 400 nm to 480 nm. The emission spectrum of the light emitting element 115R has a peak in the wavelength range of 580 nm to 700 nm. The emission spectrum of the light-emitting element 115G has a first peak in the range of 1000 nm or less. The light-emitting element 1 has a third peak at a wavelength longer than the first peak and shorter than the second peak. The emission spectrum of 15Y has a wavelength longer than the first peak and a wavelength shorter than the second peak. It has a fourth peak.

[0094] Light emitting element 115B is thicker than light emitting element 115R. Light-emitting element 115R is thicker than light-emitting element 115Y.

[0095] The difference in thickness between the light emitting element 115R and the light emitting element 115B is 40 nm or more and 90 nm or less. It is preferable that the thickness is 40 nm or more and 75 nm or less. The smaller the difference in thickness of the elements, the better the chromaticity of the light emitted by the two elements.

[0096] FIG. 4(B) shows a configuration example of each light-emitting element. Each light-emitting element has an EL layer between a pair of electrodes. The light emitting element 115R has an EL layer 113R between a first electrode 111 and a second electrode 112. The light-emitting element 115G has an EL layer 113 between a first electrode 111 and a second electrode 112. The light-emitting element 115B has an EL layer 115B between the first electrode 111 and the second electrode 112. The light-emitting element 115Y has an EL element 13B between the first electrode 111 and the second electrode 112. It has a layer 113Y.

[0097] The first electrode 111 functions as an anode, and the second electrode 112 functions as a cathode.

[0098] A reflective electrode is used for the first electrode 111, and a semi-transparent and semi-reflective electrode is used for the second electrode 112. By using a microcavity structure, the light emitted from the EL layer is shared between both electrodes. This can vibrate the second electrode 112 and intensify the light that is transmitted through and emitted from the second electrode 112.

[0099] The materials and film thicknesses of the pairs of electrodes of the four light-emitting elements shown in FIG. 4(B) are the same. This makes it possible to reduce the manufacturing cost of the display device and simplify the manufacturing process.

[0100] In FIG. 4B, the distance between a pair of electrodes of each light-emitting element corresponds to the thickness of the EL layer. The EL layer 113B is thicker than the EL layer 113R. The EL layer 113R is thicker than the EL layer 113G. The EL layer 113R is thicker than the EL layer 113Y.

[0101] The EL layer can have the same structure as that of the light-emitting element in Example 1, and therefore detailed description thereof will be omitted. .

[0102] As shown in FIG. 4B, the EL layer is formed to have a different structure for each color, so that the light-emitting element This makes it easy to produce each color with an appropriate thickness.

[0103] As with the light emitting elements of other colors, in the light emitting element 115Y, the first electrode 111 and the second electrode The thickness of the EL layer 113Y is adjusted so that the optical distance between the EL layer 113Y and the EL layer 112 is an optical distance that enhances yellow light emission. Adjust.

[0104] For example, the light emitting element 115R, the light emitting element 115G, and the light emitting element 115Y have optical The light emitting element 115B is adjusted so that the optical distance between the electrodes is 1 / 2 wavelength. It is preferable to adjust it so that

[0105] FIG. 4(C) shows an example of a configuration of each light-emitting element different from that shown in FIG. 4(B). The optical element has the same structure as that shown in FIG. 4(B) in that it has an optical adjustment layer between the first electrode and the EL layer. The light emitting element 115R has an optical adjustment layer between the first electrode 111 and the EL layer 113R. The light-emitting element 115G has an optical element between the first electrode 111 and the EL layer 113G. The light-emitting element 115B has an adjustment layer 110G. The light-emitting element 115B has an adjustment layer 110G between the first electrode 111 and the EL layer 113B. The light emitting element 115Y has an optical adjustment layer 110B between the first electrode 111 and the EL layer 113. An optical adjustment layer 110Y is provided between the first and second layers.

[0106] In FIG. 4C, the distance between a pair of electrodes of each light-emitting element is determined by the thickness of the EL layer and the optical tuning. The sum of the thickness of the EL layer 113B and the thickness of the optical adjustment layer 110B corresponds to the sum of the thickness of the EL layer 113B and the thickness of the optical adjustment layer 110B. is greater than the sum of the thickness of the EL layer 113R and the thickness of the optical adjustment layer 110R. The sum of the thickness of the EL layer 113R and the thickness of the optical adjustment layer 110R is the sum of the thickness of the EL layer 113G and the thickness of the optical adjustment layer 110R. The thickness of the EL layer 113R and the thickness of the optical adjustment layer 110R are greater than the sum of the thicknesses of the EL layer 113R and the optical adjustment layer 110R. The sum of these is greater than the sum of the thickness of the EL layer 113Y and the thickness of the optical adjustment layer 110Y.

[0107] Optical adjustment can be performed by controlling the film thickness of the EL layer and the optical adjustment layer.

[0108] The optical adjustment layer can be made of a conductive film that transmits visible light (transparent conductive film).

[0109] For a configuration example of the EL layer of each light-emitting element, the contents described in Configuration Example 1 can be referred to.

[0110] <Color gamut of display devices> The display device of this embodiment mode has a plurality of light-emitting elements and can realize full-color display. Several standard values ​​have been established as indicators of quality for full-color displays.

[0111] For example, in devices such as displays, printers, digital cameras, and scanners, An international standard color space established by the IEC (International Electrotechnical Commission) to unify the differences in color reproduction between The sRGB standard is widely established as a standard for color space. Chromaticity in the CIE1931 chromaticity coordinates (xy chromaticity coordinates) defined by the International Commission on Illumination (CIE) x,y), red (R)(x,y)=(0.640,0.330), green (G)(x,y)= (0.300,0.600), Blue (B) (x,y)=(0.150,0.060) There are.

[0112] Also, the National Television Standards Committee of the United States N is the color gamut standard for analog television systems created by the National Institute of Standards and Technology (NIS) In the TSC standard, chromaticity (x,y) is defined as red (R)(x,y)=(0.670,0.330) , green (G)(x,y)=(0.210,0.710), blue (B)(x,y)=(0.14 0,0.080).

[0113] In addition, DCI-P3 (D In the Digital Cinema Initiatives standard, chromaticity (x, y) is defined as Red (R)(x,y)=(0.680,0.320), Green (G)(x,y)=(0.265 ,0.690), and blue (B)(x,y)=(0.150,0.060).

[0114] In addition, it conforms to the high-definition UHDTV (Ultra High Definition n Television, also known as Super Hi-Vision), In the ITU-R BT.2020 standard (hereinafter referred to as BT.2020), Degrees (x,y) are red (0.708,0.292), green (0.170,0.797), It is blue (0.131, 0.046).

[0115] As described above, various standards relating to image display have been established. , light having chromaticity in the chromaticity range (area A, area B, area C) represented by the color coordinates of FIG. Light-emitting elements that emit red light, light-emitting elements that emit green light, light-emitting elements that emit blue light It is preferable to have a light-emitting element that emits light.

[0116] For example, in FIG. 1A, the light emitting element 115R is shown as area A in the color coordinate system of FIG. It is preferable that the light emitting element 115R emits light with a chromaticity in the range of 1100 to 11000 . The chromaticity x in the CIE1931 chromaticity coordinates of 6R is greater than 0.680 and less than 0.720. The chromaticity y is preferably 0.260 or more and 0.320 or less.

[0117] In addition, in FIG. 1A, the light emitting element 115G is shown in area B in the color coordinate system of FIG. It is preferable that the light emitting element 115G can emit light with a chromaticity in the range of 1100 to 11000 s.c. The chromaticity x of 6G in the CIE1931 chromaticity coordinates is 0.130 or more and 0.250 or less, The chromaticity y is preferably greater than 0.710 and equal to or less than 0.810.

[0118] In addition, in FIG. 1A, the light emitting element 115B is shown as area C in the color coordinate system of FIG. It is preferable that light emission from the light-emitting element 115B has a chromaticity in the range of 110. The chromaticity x of 6B in the CIE 1931 chromaticity coordinates is 0.120 or more and 0.170 or less, The chromaticity y is preferably equal to or greater than 0.020 and less than 0.060.

[0119] The display device may have a color filter, and each light emitting element and a color filter may be combined. When combined, the light emitted from each light-emitting element through the color filter falls within the above chromaticity range. The configuration may be such that the following is satisfied.

[0120] The peak wavelength of the emission spectrum of the light emitting element 115R is 620 nm or more and 680 nm or less. The peak wavelength of the emission spectrum of the light-emitting element 115G is preferably 500 nm or more and 53 The peak wavelength of the emission spectrum of the light emitting element 115B is preferably 430 nm or less. The light-emitting element 115R, the light-emitting element 115G, and the light-emitting element The half-width of the 115B emission spectrum is 5 nm to 45 nm, and 5 nm to 35 nm, respectively. The peak wavelength of these emission spectra is preferably 5 nm or less, and more preferably 5 nm or more and 25 nm or less. The same can be said for the half-value width after passing through the color filter.

[0121] Furthermore, by achieving the above-mentioned chromaticity, the present invention can be realized in terms of the CIE chromaticity coordinates (x, y). The color gamut of the display device of one aspect of the present invention is 80% or more in area ratio to the color gamut of BT.2020, It is preferable that the coverage rate of the color gamut is 75% or more. The ratio is 90% or more, or the coverage rate is 85% or more.

[0122] In addition, when calculating chromaticity, a color luminance meter, a spectroradiometer, or an emission spectrum measuring instrument may be used. Any deviation may be used as long as the above chromaticity is satisfied in any one of the measurements. More preferably, the above chromaticity is satisfied by any of the measurement methods.

[0123] As described above, the display device of one embodiment of the present invention can display a wide color gamut and has a wide viewing angle. Therefore, a display device with a high image quality can be provided.

[0124] <Display device configuration example 1> 6(A) to 6(C) show a display device configured to express one color using three sub-pixels of RGB colors. vinegar.

[0125] The display device shown in FIGS. 6(A) to 6(C) includes a substrate 131, a substrate 132, a transistor 135, The light emitting element 133 includes a red light emitting element 133R, a green light emitting element 133G, and a blue light emitting element 133B. do.

[0126] The display devices shown in FIGS. 6A to 6C include a transistor and a light-emitting element electrically connected to each other. It is an active matrix display device.

[0127] The display devices shown in FIGS. 6A and 6C are top-emission type, and the light emission of each light-emitting element is The light is emitted through the substrate 132. As shown in FIG. 6(B), the display device A Tom emission type can also be applied. The substrate on the light extraction side is made of a material that transmits visible light. Use materials that can be used.

[0128] The light emitting element for each color is made up of a first electrode 111, a second electrode 112, and an EL layer (EL layer 113R , EL layer 113G, or EL layer 113B).

[0129] The first electrode 111 is electrically connected to the transistor 135. The end of the first electrode 111 is covered with an insulating layer 136. The second electrode 112 is provided as a layer common to the three color light emitting elements.

[0130] The first electrode 111 shown in Figures 6(A) and 6(C) functions as a reflective electrode. The second electrode 112 shown in FIG. 6(C) functions as a semi-transmissive and semi-reflective electrode. The first electrode 111 functions as a semi-transmissive and semi-reflective electrode. The electrode 112 functions as a reflective electrode.

[0131] The blue light emitting element 133B is thicker than the red light emitting element 133R. R is thicker than that of the green light-emitting element 133G. More specifically, The inter-electrode distance is longer than the inter-electrode distance of the red light emitting element 133R. The distance between the electrodes of R is longer than the distance between the electrodes of the green light emitting element 133G. This allows for a clearer view of the display device when viewed from an oblique direction and when viewed from the front. Therefore, it is possible to realize a display device with a wide viewing angle. can.

[0132] At least one layer included in the EL layer of each light-emitting element is formed separately for each color.

[0133] The EL layer 113R, the EL layer 113G, and the EL layer 113B shown in FIGS. 6(A) and 6(B) have the following configurations: The structure is the same as that shown in FIG. 2(A). Specifically, the hole injection layer, the electron transport layer, and the electron injection layer are The hole transport layer is a common layer for the three color light emitting elements, and the hole transport layer and the light emitting layer are different for each color. In addition, in Fig. 6(A) and (B), the hole transport layer and the light emitting layer are formed of a film for each color. However, as mentioned above, if the resolution of the display device is high, There may be overlapping portions between the hole transport layers or the light emitting layers of adjacent light emitting elements. .

[0134] The configuration of the EL layer 113R, the EL layer 113G, and the EL layer 113B shown in FIG. 6(C) is the same as that shown in FIG. Specifically, the hole injection layer, the hole transport layer, the electron transport layer, and the electron The electron injection layer is a layer common to the three color light emitting elements, and the light emitting layer is a different film for each color. It is being done.

[0135] The display device shown in FIGS. 6(A) to 6(C) is configured such that the electrodes of the light emitting elements are arranged in accordance with the light emission color of each light emitting element. The optical path between the two electrodes is adjusted to form a microcavity structure. As shown, the light emitting elements of each color are arranged in the optical adjustment layer (optical adjustment layer 110R, optical adjustment layer 110G, or It may also have an optical adjustment layer 110B).

[0136] The light emitting element is sealed by the substrate 131, the substrate 132, and the adhesive layer 137. The space 134 surrounded by the substrate 131, the substrate 132, and the adhesive layer 137 has the following configuration: This prevents impurities such as moisture and oxygen from entering the light-emitting element, extending the life of the light-emitting element. The space 134 is preferably a reduced pressure atmosphere. 134 is preferably filled with an inert gas such as a rare gas or nitrogen gas, or an organic resin. In addition, in FIG. 6(B), since it is not necessary to extract light through the space 134, the space 1 It is easy to secure space within 34 to place a desiccant or the like.

[0137] With the above-described configuration, a display device with a wide viewing angle can be obtained.

[0138] <Configuration example 2 of the display device> In this configuration example, a flexible display device will be described. 7B is a cross-sectional view of the display unit 381 of the display device 10A and the FPC 3 7C is a cross-sectional view of the connection portion with the display device 10A. 10B is a cross-sectional view of FIG.

[0139] The display device 10A and the display device 10B are not intended to be held in a bent state or be repeatedly bent. The components of the display device 10A and the display device 10B are each It is made of a flexible material.

[0140] The flexible display device 10A and the flexible display device 10B are used with the display unit 381 bent. By applying one embodiment of the present invention, Therefore, the viewing angle of the display device 10A and the display device 10B can be widened. Even when the 81 is bent, there is little change in chromaticity due to the angle, and good display quality can be obtained. do.

[0141] The display device 10A and the display device 10B each include a display unit 381 and a drive circuit unit 382. An FPC 372 is attached to each of the display device 10A and the display device 10B.

[0142] The conductive layer 43c and the FPC 372 are electrically connected via the connector 76 (FIG. 7( The conductive layer 43c is made of the same material as the source and drain of the transistor. They can be formed in the same process.

[0143] The connector 76 may be made of various anisotropic conductive films (ACF). Conductive Film) and Anisotropic Conductive Paste (ACP) Conductive Paste) can be used.

[0144] The display device 10A shown in Figures 7(A) and (B) has a protective layer 75 and a substrate 29. The 75 side is the display surface side of the display device 10A. The protective layer 75 has high transparency to visible light. If the protective layer 75 has an organic insulating film, the surface of the display device 10A is not easily scratched. This is preferable because it can prevent the film from breaking down or cracking.

[0145] The display device 10A shown in FIG. 7B has a transistor 40 on an insulating layer 31. 9 is attached to the insulating layer 31 by an adhesive layer 28. On the transistor 40, An insulating layer 33 and an insulating layer 34 are provided. Openings provided in the insulating layer 33 and the insulating layer 34 The transistor 40 and the light emitting element 60 are electrically connected via the port. The end of the lower electrode is covered with an insulating layer 35. The insulating layer 74 is provided. The light emitting element 60 is sealed by the insulating layer 74. It can also be said that.

[0146] The transistor 40 is a bottom-gate transistor having a semiconductor layer 42 .

[0147] As the semiconductor layer 42, it is preferable to use a metal oxide layer that functions as an oxide semiconductor layer. Like oxide semiconductors, they have a wider band gap than silicon and a higher carrier density. By using a semiconductor material with a low resistance, the current in the off state of the transistor can be reduced. preferable.

[0148] However, in the display device of one embodiment of the present invention, a semiconductor layer of a transistor includes a metal oxide. For example, in the display device of one embodiment of the present invention, a semiconductor layer of a transistor Silicon can be used in the form of amorphous silicon or crystalline silicon. Crystalline silicon can be used. Examples of crystalline silicon include microcrystalline silicon and polycrystalline silicon. Examples of silicon include low-temperature polysilicon (LTP) and single-crystal silicon. It is preferable to use low temperature polysilicon (S). Polycrystalline silicon such as LTPS can be formed at a lower temperature than single-crystal silicon, and It also has higher field-effect mobility and higher reliability than amorphous silicon.

[0149] In the transistor 40, a portion of the conductive layer 41 functions as a gate, and a portion of the insulating layer 32 The conductive layer 43a and the conductive layer 43b function as a source or a drain, respectively. It functions as either a drain or a gate.

[0150] A display device 10B shown in FIG. 7C does not include the transistor 40 but includes a transistor 49. and that the protective layer 75 is not provided, but the substrate 75a and adhesive layer 75b are provided. 7(A) and (B) is different from the display device 10A shown in FIG. Detailed explanations of these will be omitted.

[0151] The transistor 49 shown in FIG. 7C is a transistor having a semiconductor layer and two gates. be.

[0152] In the transistor 49, a portion of the conductive layer 41 functions as a gate, and a portion of the insulating layer 31 functions as a gate insulating layer, a portion of insulating layer 46 functions as a gate insulating layer, and conductive layer 4 A part of 5 functions as a gate. The semiconductor layer is made up of a channel region 42a and a low resistance region 42b. The channel region 42a overlaps with the conductive layer 45 via the insulating layer 46. 2b has a portion connected to conductive layer 43a and a portion connected to conductive layer 43b.

[0153] The transistor 49 has a structure in which a semiconductor layer in which a channel is formed is sandwiched between two gates. By adopting such a configuration, the threshold voltage of the transistor can be controlled. By connecting the two gates and applying the same signal to them, the transistor Such a transistor may drive a field effect transistor compared to other transistors. This allows for increased mobility and increased on-state current. Furthermore, the area occupied by the circuit portion can be reduced. By using a transistor with a large on-state current, it is possible to increase the size of the display device. Even if the number of wires increases when the resolution is increased, the signal delay in each wire can be reduced. This makes it possible to suppress display unevenness.

[0154] Alternatively, a potential for controlling the threshold voltage is applied to one of the two gates, and a drive voltage is applied to the other. By applying a potential for the transistor, the threshold voltage of the transistor can be controlled.

[0155] <Configuration example 3 of the display device> In this configuration example, a flexible display device will be described. 8(B) and 8(C) show a multi-display system using four display devices 100. 1 shows a perspective view of a ray.

[0156] The display device 100 can be held in a bent state and can be bent repeatedly. Each of the components of the display device 100 is made of a flexible material. By applying this aspect, the viewing angle of the display device 100 can be widened. Even when the display device 100 is bent, there is little change in chromaticity depending on the angle, and a good display quality is obtained. You will get a rank.

[0157] In addition, a multi-display can be produced by combining a plurality of display devices 100. It is easy to make the multi-display larger. By applying one aspect of the present invention, The viewing angle of the display device 100 can be widened. Even when several people are watching from different angles at the same time, the color tone changes little depending on the angle. Good display quality can be obtained. In addition, the display area of ​​the multi-display can be displayed as a curved surface. In this case, good display quality can be obtained.

[0158] The display device 100 has a display area 101 and an area 102. The area 102 is transparent to visible light. The visible light transmitting region 119 and the visible light blocking region 120 are The visible light blocking area 120 is adjacent to the display area 101. In the display device 100, regions 119 that transmit visible light are arranged along two sides of the display region 101. The width W of the region 119 that transmits visible light along one side of the display region 101 and the width W of the region 119 that transmits visible light along the other side of the display region 101 are The width W of the visible light transmitting region 119 along one side of the FIG. 8(A) shows an example where they are the same.

[0159] The multi-display 22 shown in FIGS. 8B and 8C is the same as the display device 100 shown in FIG. There are four of these in a 2x2 matrix (two in the vertical and two in the horizontal directions). 8B is a perspective view of the display surface side of the multi-display 22, and FIG. 8C is a perspective view of the multi-display 22. 2 is a perspective view of the display 22 from the side opposite to the display surface side.

[0160] 8(B) and (C) show an example in which each display device is electrically connected to an FPC.

[0161] The multi-display 22 shown in FIGS. 8(B) and 8(C) includes display devices 100a, 100b, and 100c. Available in 00c and 100d.

[0162] In FIGS. 8B and 8C, the short sides of the display devices 100a and 100b overlap each other, and the display area A part of the area 101a and a part of the area 119b that transmits visible light overlap each other. The long sides of the devices 100a and 100c overlap, forming a part of the display area 101a and a part of the visible light transmitting area 102b. The areas 119c overlap each other.

[0163] In FIGS. 8B and 8C, a part of the display area 101b is a visible light transmitting area 119. The display area 119c overlaps with a part of the area 119d that transmits visible light, and the area 119d that transmits visible light overlaps with a part of the area 119c that transmits visible light. A part of O1c overlaps with a part of the region 119d that transmits visible light.

[0164] Therefore, as shown in FIG. 8(B), the display areas 101a to 101d are arranged seamlessly. The area thus obtained can be used as the display area 23 of the multi-display 22.

[0165] In the center of the multi-display 22, the display device 100b overlaps the display device 100a. The display device 100c is overlapped on the display device 100b, and the display device 100c is overlapped on the display device 100c. 0d overlaps.

[0166] The display device 100 is flexible. This allows, for example, Then, the vicinity of the FPC 109a of the display device 100a is curved, and the surface adjacent to the FPC 109a is A part of the display device 100a and the FPC 10 are disposed below the display area 101b of the display device 100b. As a result, the FPC 109a can be attached to the back of the display device 100b. The display device 100a and the display device 100b can be arranged without interfering with each other physically. When the FPC 109a and the FPC 100b are stacked and fixed, there is no need to consider the thickness of the FPC 109a. , the difference in height between the upper surface of the region 119b that transmits visible light and the upper surface of the display device 100a is reduced. As a result, the edge of the display device 100b located above the display area 101a can be made less noticeable. It is possible.

[0167] Furthermore, by making the display device 100 flexible, the display area 101 of the display device 100b The height of the upper surface at b is the same as the height of the upper surface at the display area 101a of the display device 100a. The display device 100b can be curved gently so as to match the curve of the display device 100a. The heights of the display areas are aligned except for the area where the display device 100a and the display device 100b overlap and the vicinity thereof. The display quality of the image displayed in the display area 23 of the multi-display 22 can be improved. It can be increased.

[0168] The display device of this embodiment is applied with a color-coded method, and the light-emitting element has a microcavity. For example, full color LEDs are produced by using light-emitting elements of two or more colors, including red and blue. When realizing a display, the thickness (or inter-electrode distance) of the blue light-emitting element is made the thickest, and the red By making the thickness of the light-emitting element (or the distance between the electrodes) the second thickest, when viewed from an oblique angle, This can reduce color shifts in red, blue, and white, thereby widening the viewing angle of the display device. It is also possible to display a wide color gamut.

[0169] This embodiment mode can be combined with other embodiment modes as appropriate. In the case where multiple configuration examples are shown in one embodiment, the configuration examples may be combined as appropriate. It is possible to do this.

[0170] (Embodiment 2) In this embodiment, a light-emitting element that can be used for a display device according to one embodiment of the present invention will be described. 2(B) will be used to explain.

[0171] In this embodiment, materials that can be used for the light-emitting element exemplified in Embodiment 1 will be described. , mainly explains.

[0172] <First electrode and second electrode> The first electrode 111 shown in FIG. 2B is an electrode having reflectivity to visible light (a reflective electrode). The reflectance of the reflective electrode for visible light is 40% or more and 100% or less, preferably 70% or more. The resistivity of the first electrode 111 is 1×10 -2 Ωcm or less is preferred Desirable.

[0173] The second electrode 112 shown in FIG. 2(B) is a semi-transmissive and semi-reflective electrode. The reflectance of visible light is set to 20% or more and 80% or less, preferably 40% or more and 70% or less. The resistivity of the second electrode 112 is 1×10 -2 Ωcm or less is preferable.

[0174] The optical adjustment layers 110R, 110G, and 110B shown in FIG. 2(B) have a transparency to visible light. The transparent electrode has a visible light transmittance of 40% or more. The resistivity of the adjustment layers 110R, 110G, and 110B is 1×10 -2 Ωcm or less is preferable.

[0175] The first electrode 111, the second electrode 112, and the optical adjustment layers 110R, 110G, and 110B are As for the material to be used, if it can fulfill the functions of both electrodes described above, the following materials can be used: Suitable combinations can be used. For example, metals, alloys, electrically conductive compounds, and the like can be used. A mixture of these materials can be used as appropriate. Specifically, In—Sn oxide (ITO and In-Si-Sn oxide (also called ITSO), In-Zn oxide, In-W -Zn oxide. Other examples include aluminum (Al), titanium (Ti), chromium ( Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (C u), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum Mo, Tantalum (Ta), Tungsten (W), Palladium (Pd), Gold (Au) , metals such as platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd), and An alloy containing a suitable combination of these elements may also be used. Elements in Groups 1 and 2 of the periodic table (e.g., lithium (Li), cesium (Cs) ), calcium (Ca), strontium (Sr), europium (Eu), ytter Rare earth metals such as Yb, and alloys containing appropriate combinations of these, graphene etc. can be used.

[0176] <Hole injection layer and hole transport layer> The hole injection layer 121 injects holes from the first electrode 111, which is an anode, into the EL layer. The layer is a layer containing a material with high hole injection properties.

[0177] Materials with high hole injection properties include molybdenum oxide, vanadium oxide, and ruthenium oxide. Examples of oxides of transition metals include oxides of tungsten, manganese, and the like. Phthalocyanine (abbreviated as HPc) and copper phthalocyanine (abbreviated as CuPC) The 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenyl N,N'-bis[4-[bis(3-methylphenyl)amino]biphenyl (abbreviation: DPAB), (phenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4, Aromatic amine compounds such as 4'-diamine (abbreviated as DNTPD) or poly(3,4-ene) PEDOT / PSS ) and other polymers can be used.

[0178] In addition, materials with high hole injection properties include hole transport materials and acceptor materials (electron acceptor materials). In this case, a composite material containing an acceptor material can be used. Electrons are extracted from the hole transport material, generating holes in the hole injection layer 121, and the holes are transported to the hole transport layer 12. Holes are injected into the light-emitting layer through the hole injection layer 121. It may be formed as a single layer made of a composite material containing an acceptor material (electron-accepting material), The hole transport material and the acceptor material (electron acceptor material) are laminated in separate layers. It may be formed.

[0179] The hole transport layer 122 transports holes injected from the first electrode 111 by the hole injection layer 121. The hole transport layer 122 is a layer that contains a hole transport material. The hole transport material used for the hole transport layer 122 is particularly It is preferable to use a compound having a HOMO level equal to or close to the above.

[0180] Acceptor materials used in the hole injection layer 121 include those of Group 4 to 5 in the periodic table. Oxides of metals belonging to Group 8 can be used. Specifically, molybdenum oxide, Vanadium, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide Among them, molybdenum oxide is particularly stable in the atmosphere and is easily absorbed. It is preferred because it has low moisture resistance and is easy to handle. Other examples include quinodimethane derivatives and chloranil derivatives. Organic acceptors such as hexaazatriphenylene derivatives can be used. Specifically, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (Abbreviation: F4-TCNQ), chloranil, 2,3,6,7,10,11-hexacyano- 1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN) It is possible.

[0181] The hole transport material used in the hole injection layer 121 and the hole transport layer 122 is 10 -6 cm 2 A material having a hole mobility of 1 / Vs or more is preferred. Any other suitable substance may be used.

[0182] As hole transport materials, π-electron-rich heteroaromatic compounds (e.g., carbazole derivatives, Indole derivatives) and aromatic amine compounds are preferred, and specific examples include 4,4'-bis [N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as NPB or α-N PD), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'- Biphenyl]-4,4'-diamine (abbreviation: TPD), 4,4'-bis[N-(spiro- 9,9'-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSP B), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl) Triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl- 9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 3-[ 4-(9-phenanthryl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPPn), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluorene- 2-yl)-9-phenyl-9H-carbazol-3-amine (abbreviation: PCBiF), N -(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-2-yl)] 9,9-dimethyl-9H-fluoren-2-amine (abbreviated as PCBBiF), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole -3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)- 4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: P CBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carba (3-phenyl-2-azol-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N -phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl] Fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl -9H-carbazol-3-yl)phenyl]spiro-9,9'-bifluorene-2-a PCBASF (abbreviation: PCBASF), 4,4',4''-tris(carbazol-9-yl)trimethylsilyl Triphenylamine (abbreviation: TCTA), 4,4',4''-tris(N,N-diphenyl) amino)triphenylamine (abbreviation: TDATA), 4,4',4''-tris[N-( 3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: MTDATA ), compounds with aromatic amine skeletons such as 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N-carbazolyl)biphenyl (abbreviation: CBP), 3 ,6-Bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzT P), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), 3- [N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenyl Carbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazole [N-3-yl]-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPC A2), 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)a amino]-9-phenylcarbazole (abbreviation: PCzPCN1), 1,3,5-tris[4 -(N-carbazolyl)phenyl]benzene (abbreviation: TCPB), 9-[4-(10-furan (phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), etc. Compounds with a carbazole skeleton, 4,4',4''-(benzene-1,3,5-trimethylsilyl) yl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl- 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene DBTFLP-III, 4-[4-(9-phenyl-9H-fluorene-9 -yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV) Which compound has a thiophene skeleton, 4,4',4''-(benzene-1,3,5-trimethylsilyl) 4-[3-[3-(9-furanyl)tri(dibenzofuran)(abbreviation: DBF3P-II) (phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: m Examples include compounds with a furan skeleton such as mDBFFLBi-II).

[0183] Furthermore, poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenyl ether) Nylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenyl amino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide]( abbreviation: PTPDMA), poly[N,N'-bis(4-butylphenyl)-N,N'-bis (phenyl)benzidine (abbreviated as Poly-TPD) It is also possible.

[0184] However, the hole transport material is not limited to the above, and one or more of various known materials may be used. The hole-transporting material may be used in combination in the hole injection layer 121 and the hole transport layer 122. The hole transport layer may be formed from a plurality of layers. The first hole transport layer and the second hole transport layer may be laminated.

[0185] <Light-emitting layer> The light-emitting layer is a layer containing a light-emitting substance. A material that emits light of a color such as yellow, yellow-green, yellow, orange, or red is appropriately used. A structure that uses different luminescent materials to produce different luminescent colors (for example, complementary colors) Furthermore, it is possible to obtain white light by combining the different luminescent colors of the light-emitting layer. The light emitting element may have a laminated structure in which the light emitting elements have different light emitting materials.

[0186] The light-emitting layer contains one or more compounds (host material, The one or more compounds may include the following: One or both of the hole transporting material and the electron transporting material described in the above embodiment can be used. do.

[0187] The light-emitting layer 123R contains a substance that emits red light (a red light-emitting substance). The light-emitting layer 123B contains a substance that emits green light (a green light-emitting substance). It contains a substance that emits blue light.

[0188] A blue luminescent material is used that converts singlet excitation energy into visible light. Green and red luminescent materials are luminescent materials that convert triplet excitation energy into luminescence in the visible light region. Using quality is preferable because it improves the RGB spectral balance.

[0189] The light-emitting layer of the light-emitting element 115Y that emits yellow light 116Y shown in FIG. 4(A) contains a yellow A substance that emits yellow light (a yellow light-emitting substance) can be used. It is preferable to use a light-emitting substance that converts the doublet excitation energy into light emission in the visible light region.

[0190] The light-emitting material that can be used in the light-emitting layer is not particularly limited, and may be any material having a singlet excitation energy luminescent material that converts triplet excitation energy into visible light emission, or The luminescent material may be, for example, the following: Examples include:

[0191] Luminescent materials that convert singlet excitation energy into light include fluorescent materials. Examples thereof include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, and the like. Olene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives , dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives Pyrene derivatives are particularly well known for their The photon yield is high, which is preferable. Specific examples of pyrene derivatives include N,N'-bis(3- methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl )phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N, N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl] )phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-biphenyl N,N'-diphenylpyrene-1,6-diamine (abbreviation) Name: 1,6FrAPrn), N,N'-bis(dibenzothiophen-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]fura N,N'-(pyrene-1,6-diamine) (abbreviation: 1,6BnfAPrn), yl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-02), N,N'-(pyren-1,6-diyl)bis[ (6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation :1,6BnfAPrn-03) and the like. The pyrene derivative is This is a group of compounds that are useful for achieving good blue chromaticity in display devices.

[0192] In addition, 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2, 2'-Bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl- 9-anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2B Py), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N' -Diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-calcium (bazol-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (Abbreviation: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-di N,9-diphenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA) Phenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazo PCAPA, 4-(10-phenyl-9-anthryl)-4 '-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PC BAPA), 4-[4-(10-phenyl-9-anthryl)phenyl]-4'-(9- Phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPBA ), perylene, 2,5,8,11-tetra(tert-butyl)perylene (abbreviation: TBP ), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1- phenylene)bis[N,N',N'-triphenyl-1,4-phenylenediamine](abbreviation Name: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-a N-(2-phenyl-9H-carbazol-3-amine (abbreviation: 2PCAPPA), -[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-tri Phenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA) and the like can be used. do.

[0193] Furthermore, examples of luminescent materials that convert triplet excitation energy into luminescence include phosphorescent materials. and thermally activated delayed fluorescence (TDF) TADF (Tajikistan Activated Delayed Fluorescence) material Examples include:

[0194] Phosphorescent materials include organometallic complexes, metal complexes (platinum complexes), and rare earth metal complexes. These emit different colors (emission peaks) depending on the substance, so they should be selected appropriately as needed. Select and use.

[0195] It has a blue or green color and the peak wavelength of the emission spectrum is between 450 nm and 570 nm. Some phosphorescent materials include the following:

[0196] For example, tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl )-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium (III) (abbreviation: [Ir(mpptz-dmp)3]), tris(5-methyl-3,4 -diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir (Mptz)3]), tris[4-(3-biphenyl)-5-isopropyl-3-phenyl [Ir(iPrp)] tz-3b)3]), tris[3-(5-biphenyl)-5-isopropyl-4-phenyl [Ir(iPr5 btz)3]), organometallic complexes with a 4H-triazole skeleton, such as tris[3- Methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato ]iridium(III) (abbreviation: [Ir(Mptz1-mp)3]), tris(1-methyl Iridium(II) I) (abbreviation: [Ir(Prtz1-Me)3]) Organometallic complexes containing fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl]propanol [phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpmi)3 ]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f] [Ir(dmpimpt-Me)3 organometallic complexes with imidazole skeletons, such as bis[2-(4',6'-difluoromethyl] (O-phenyl)pyridinato-N,C 2’ ]iridium(III) tetrakis(1-pyrazoline) aryl)borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pi Lysinato-N,C 2’ ] Iridium(III) picolinate (abbreviation: FIrpic), bis[2-(3,5-bistrifluoromethylphenyl)pyridinato-N,C 2’ ]Iriji Ir(III) picolinate (abbreviation: [Ir(CF3ppy)2(pic)]), bis[ 2-(4',6'-difluorophenyl)pyridinato-N,C 2’ ] Iridium (III ) acetylacetonate (abbreviation: FIr(acac)) Examples of suitable organic compounds include organometallic complexes having a diphenylpyridine derivative as a ligand.

[0197] It is green or yellow and the peak wavelength of the emission spectrum is between 495 nm and 590 nm. Some phosphorescent materials include the following:

[0198] For example, tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation :[Ir(mppm)3]), tris(4-t-butyl-6-phenylpyrimidinato)i Lithium(III) (abbreviation: [Ir(tBuppm)3]), (acetylacetonato)bis(trimethylsilyl) Bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(m ppm)2(acac)]), (acetylacetonato)bis(6-tert-butyl-4 -phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)2(a cac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenyl [Pyrimidinato]iridium(III) (abbreviation: [Ir(nbppm)2(acac)]) , (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenyl [Ir(mpmppm)2(acac)]iridium(III) ]), (acetylacetonato)bis{4,6-dimethyl-2-[6-(2,6-dimethyl phenyl)-4-pyrimidinyl-κN3]phenyl-κC}iridium(III) (abbreviation :[Ir(dmppm-dmp)2(acac)]), (acetylacetonato)bis(4 ,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2( organometallic iridium complexes with pyrimidine skeletons, such as (acetyl acac)] cetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III)( Abbreviation: [Ir(mppr-Me)2(acac)]), (acetylacetonato)bis(5 -isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: Organometallic pyrazine skeletons such as [Ir(mppr-iPr)2(acac)] Iridium complex, tris(2-phenylpyridinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(ppy)3]), bis(2-phenylpyridinato-N,C 2’ ) Iriji Ir(III) acetylacetonate (abbreviation: [Ir(ppy)2(acac)]), (benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: [I r(bzq)2(acac)]), tris(benzo[h]quinolinato)iridium(II I) (abbreviation: [Ir(bzq)3]), tris(2-phenylquinolinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(pq)3]), bis(2-phenylquinolinato- N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: [Ir(pq)2(a organometallic iridium complexes with pyridine skeletons, such as bis(2,4-di(cac)]) Phenyl-1,3-oxazolato-N,C 2’ ) Iridium(III) acetylacetonate Ir(dpo)2(acac)]), bis{2-[4'-(perfluorooctanoic acid Phenyl)phenyl]pyridinato-N,C 2’}Iridium(III) acetylacetonate Ir(p-PF-ph)2(acac)]), bis(2-phenylbenzo[Ir(p-PF-ph)2(acac)] Thiazolato-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: [Ir( bt)2(acac)]), as well as organometallic complexes such as tris(acetylacetonato)(mono [Tb(acac)3(Phen) ]) are examples of rare earth metal complexes.

[0199] Among the above, those having a pyridine skeleton (particularly a phenylpyridine skeleton) or a pyrimidine skeleton are The organometallic iridium complex can improve the chromaticity of green in the display device of one embodiment of the present invention. This is a group of compounds useful for achieving this.

[0200] Yellow or red, with a peak wavelength of 570 nm or more and 750 nm or less in the emission spectrum. Some phosphorescent materials include the following:

[0201] For example, (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinyl] dinato]iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)yl Ir(III) (abbreviation: [Ir(5mdppm)2(dpm)]), (dipivaloylmethyl Thanato)bis[4,6-di(naphthalen-1-yl)pyrimidinato]iridium(III ) (abbreviation: [Ir(d1npm)2(dpm)]) Metal complex, (acetylacetonato)bis(2,3,5-triphenylpyrazinato)iridide Ir(tppr)2(acac)], bis(2,3,5-trimethylsilyl) (triphenylpyrazinate)(dipivaloylmethanato)iridium(III) (abbreviation: [Ir (tppr)2(dpm)]), bis{4,6-dimethyl-2-[3-(3,5-dimethyl {(2,6-dimethylphenyl)-5-phenyl-2-pyrazinyl-κN]phenyl-κC} ... thyl-3,5-heptanedionate-κ 2 O,O')iridium(III) (abbreviation: [Ir (dmdppr-P)2(dibm)]), bis{4,6-dimethyl-2-[5-(4- Cyano-2,6-dimethylphenyl)-3-(3,5-dimethylphenyl)-2-pyrazine {(2,2,6,6-tetramethyl-3,5-heptanedioic acid)-N-phenyl-κC}(2,2,6,6-tetramethyl-3,5-heptanedioic acid) Nat-κ 2 O,O')iridium(III) (abbreviation: [Ir(dmdppr-dmCP) 2(dpm)]), (acetylacetonato)bis[2-methyl-3-phenylquinoxalate Nat-N,C 2’ ]Iridium(III) (abbreviation: [Ir(mpq)2(acac)]) , (acetylacetonato)bis(2,3-diphenylquinoxalinato-N,C 2’ ) Iri Ir(dpq)2(acac) (acetylacetonate) ) Bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) Organometallic compounds with a pyrazine skeleton, such as [Ir(Fdpq)2(acac)] complexes and tris(1-phenylisoquinolinato-N,C 2’ ) Iridium (III) (abbreviation Name: [Ir(piq)3]), bis(1-phenylisoquinolinato-N,C 2’ ) Iriji Ir(piq)2(acac) Organometallic complexes with pyridine skeletons, such as 2,3,7,8,12,13,17,18- octaethyl-21H,23H-porphyrin platinum(II) (abbreviation: [PtOEP]) Platinum complexes such as tris(1,3-diphenyl-1,3-propanedionato)(monofenadine) (Eu(DBM)3(Phen)]), Tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthate) Europium(III) (abbreviated as [Eu(TTA)3(Phen)]) Rare earth metal complexes are included.

[0202] Among the above, the organometallic iridium complex having a pyrazine skeleton is an embodiment of the present invention. This is a group of compounds that are useful for achieving good red chromaticity in devices. Organometallic iridium complexes containing cyano groups, such as [mdppr-dmCP)2(dpm)]. The body is stable and desirable.

[0203] In addition, blue luminescent materials are those with a photoluminescence peak wavelength of 430 nm or more. It is preferable to use a substance with a wavelength of 70 nm or less, more preferably 430 nm or more and 460 nm or less. In addition, green luminescent materials with a photoluminescence peak wavelength of 500 nm Use a substance with a wavelength of 540 nm or more, more preferably 500 nm or more and 530 nm or less. As the red luminescent material, a material having a photoluminescence peak wavelength of 610 nm is preferable. Use a substance with a wavelength of 680 nm or more, more preferably 620 nm or more and 680 nm or less. The photoluminescence measurement may be performed on either a solution or a thin film.

[0204] By using such compounds in combination with the microcavity effect, the above-mentioned colors can be more easily obtained. At this point, the semi-transparent light necessary to achieve the microcavity effect can be achieved. The thickness of the semi-reflective electrode (metal thin film portion) is preferably 20 nm or more and 40 nm or less. Preferably, it is greater than 25 nm and less than 40 nm. However, if it exceeds 40 nm, the efficiency will decrease. There is a possibility that this may happen.

[0205] The compounds used in the light-emitting layer (host material, assist material) include light-emitting materials (guest materials) One or more substances with an energy gap larger than the energy gap of The hole transport material described above and the electron transport material described later are used by selecting the appropriate material. Each of them can be used as a host material or an assist material.

[0206] When the light-emitting substance is a fluorescent material, the host material should have an energy level of 0.05 to 0.15 in the singlet excited state. It is preferable to use an organic compound having a large energy level and a small energy level in the triplet excited state. For example, it is preferable to use an anthracene derivative or a tetracene derivative. -phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carba PCzPA (abbreviation: PCzPA), 3-[4-(1-naphthyl)-phenyl]-9-phenyl -9H-carbazole (abbreviation: PCPN), 9-[4-(10-phenyl-9-anthraquinone] 7-[4-(10-phenyl)phenyl]-9H-carbazole (abbreviation: CzPA), [c,g]carbazole (abbreviation: c gDBCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]- Benzo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl- 10-{4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4'-yl} Anthracene (abbreviation: FLPPA), 5,12-diphenyltetracene, 5,12-bis (biphenyl-2-yl)tetracene.

[0207] When the light-emitting material is a phosphorescent material, the host material is a material that has triplet excitation energy of the light-emitting material. (energy difference between the ground state and the triplet excited state) In this case, zinc or aluminum metal complexes, oxalates, etc. sadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives Conductors, dibenzoquinoxaline derivatives, dibenzothiophene derivatives, dibenzofuran derivatives , pyrimidine derivatives, triazine derivatives, pyridine derivatives, bipyridine derivatives, phenane Examples of usable compounds include thiazoline derivatives, aromatic amines, and carbazole derivatives.

[0208] Specifically, tris(8-quinolinolato)aluminum(III) (abbreviation: Alq), Tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), Bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (BeBq 2) Bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum (III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq ), bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: Zn(B OX)2), bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: Z nBTZ), metal complexes such as 2-(4-biphenylyl)-5-(4-tert-butylphenyl) phenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(p- tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation Name: OXD-7), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butyl) 2,2',2''-(1-phenylphenyl)-1,2,4-triazole (abbreviation: TAZ), ,3,5-benzenetriyl)-tris(1-phenyl-1H-benzimidazole)( abbreviation: TPBI), bathophenanthroline (abbreviation: BPhen), bathocuproine (abbreviation: Name: BCP), 2,9-bis(naphthalen-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), etc. and aromatic amine compounds such as NPB, TPD, and BSPB.

[0209] In addition, anthracene derivatives, phenanthrene derivatives, pyrene derivatives, chrysene derivatives, di Condensed polycyclic aromatic compounds such as benzo[g,p]chrysene derivatives are included. ,10-Diphenylanthracene (abbreviation: DPAnth), N,N-diphenyl-9-[ 4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (Abbreviation: CzA1PA), 4-(10-phenyl-9-anthryl)triphenylamine (abbreviation: DPhPA), YGAPA, PCAPA, N,9-diphenyl-N-{4-[4 -(10-phenyl-9-anthryl)phenyl]phenyl}-9H-carbazole-3 -amine (abbreviation: PCAPBA), 9,10-diphenyl-2-[N-phenyl-N-( 9-phenyl-9H-carbazol-3-yl)amino]anthracene (abbreviation: 2PCA PA), 6,12-dimethoxy-5,11-diphenylchrysene, N,N,N',N', N'',N'',N''',N'''-Octaphenyldibenzo[g,p]chrysene-2 ,7,10,15-tetraamine (abbreviation: DBC1), 9-[4-(10-phenyl-9 -anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 3,6-diphenyl Phenyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazo (abbreviation: DPCzPA), 9,10-bis(3,5-diphenylphenyl)anthracene DPPA), 9,10-di(2-naphthyl)anthracene (DNA), 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuD NA), 9,9'-bianthryl (abbreviation: BANT), 9,9'-(stilbene-3,3 '-diyl)diphenanthrene (abbreviation: DPNS), 9,9'-(stilbene-4,4' -diyl)diphenanthrene (abbreviation: DPNS2), 1,3,5-tri(1-pyrenyl) Benzene (abbreviation: TPB3) and the like can be used.

[0210] In addition, when multiple compounds are used in the light-emitting layer, the compound that forms the exciplex is mixed with the light-emitting substance. In this case, various compounds can be used in appropriate combination. However, to efficiently form an exciplex, a compound that readily accepts holes (hole transporting compound) is required. The combination of a compound that easily accepts electrons (electron transporting material) and a compound that easily accepts electrons (electron transporting material) is particularly Specific examples of the hole transporting material and the electron transporting material are described in the present embodiment. The materials shown in the following examples can be used.

[0211] TADF materials are materials that convert triplet excited states into singlet excited states using a small amount of thermal energy. It is possible to convert the electrons into electrons (reverse intersystem crossing) and efficiently emit light (fluorescence) from the singlet excited state. In addition, the conditions for efficiently obtaining thermally activated delayed fluorescence are three The energy difference between the doublet excitation level and the singlet excitation level is 0 eV or more and 0.2 eV or less, preferably The delayed fluorescence in TADF materials is between 0 eV and 0.1 eV. The light is an emission that has a spectrum similar to that of normal fluorescence, but has a significantly longer lifespan. The lifespan of -6 seconds or more, preferably 10 -3 More than a second.

[0212] TADF materials include, for example, fullerenes and their derivatives, and acridines such as proflavine. Derivatives, eosin, etc. Also, magnesium (Mg), zinc (Zn), cadmium Cd, Sn, Pt, In, or Palladium Examples of metal-containing porphyrins include metal-containing porphyrins containing Pd, etc. For example, protoporphyrin-tin fluoride complex (SnF2(Proto IX)), mesoporphyrin Porphyrin-tin fluoride complex (SnF2(Meso IX)), hematoporphyrin Tin fluoride complex (SnF2(Hemato IX)), coproporphyrin tetramethyl Ester-tin fluoride complex (SnF2(Copro III-4Me)), octaethyl Porphyrin-tin fluoride complex (SnF2(OEP)), etioporphyrin-tin fluoride SnF2(Etio I) complex, octaethylporphyrin-platinum chloride complex (Pt Cl2OEP) etc.

[0213] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[ 2,3-a]carbazol-11-yl)-1,3,5-triazine (PIC-TRZ) , 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazo {4,6-diphenyl-1,3,5-triazine (PCCz PTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4,6- Diphenyl-1,3,5-triazine (PXZ-TRZ), 3-[4-(5-phenyl- 5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2 ,4-triazole (PPZ-3TPT), 3-(9,9-dimethyl-9H-acridine -10-yl)-9H-xanthen-9-one (ACRXTN), bis[4-(9,9- Dimethyl-9,10-dihydroacridine)phenyl]sulfone (DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthracene]- π-electron rich heteroaromatic rings and π-electron deficient heteroaromatic rings such as 10'-one (ACRSA) It is to be noted that the π-electron rich heteroaromatic ring and the π-electron deficient heteroaromatic ring can be used. The substance in which the π-electron-rich heteroaromatic ring is directly bonded to the π-electron-deficient heteroaromatic ring exhibits the donor property of the π-electron-rich heteroaromatic ring. The acceptor properties of the toe-shaped heteroaromatic rings are both strong, and the energies of the singlet and triplet excited states are This is particularly preferable because the energy difference is small.

[0214] When using a TADF material, it can also be used in combination with other organic compounds.

[0215] <Electron transport layer> The electron transport layer 124 transports electrons injected from the second electrode 112 by the electron injection layer 125. The electron transport layer 124 is a layer that transports electrons to the light-emitting layer. The electron transporting material used in the electron transport layer 124 is 1×10 -6 cm 2 / Vs or more electrons It is preferable that the material has a high electron transporting property than the hole transporting property. Others than these may be used.

[0216] Electron transporting materials include quinoline ligands, benzoquinoline ligands, and oxazole ligands. or metal complexes having thiazole ligands, oxadiazole derivatives, triazoles derivatives, phenanthroline derivatives, pyridine derivatives, bipyridine derivatives, etc. In addition, π-electron deficient heteroaromatic compounds such as nitrogen-containing heteroaromatic compounds can be used. It is also possible.

[0217] Specifically, Alq3, tris(4-methyl-8-quinolinolato)aluminum (abbreviated as Almq3), bis(10-hydroxybenzo[h]quinolinato)beryllium (abbreviation: B eBq2), BAlq, Zn(BOX)2, bis[2-(2-hydroxyphenyl)benzoate] 2-(4-biphenylyl)-2-benzothiazolato-zinc (abbreviated as Zn(BTZ)2) phenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxa Diazol-2-yl]benzene (abbreviation: OXD-7), 3-(4'-tert-butyl phenyl)-4-phenyl-5-(4''-biphenyl)-1,2,4-triazole( Abbreviation: TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl) -5-(4-biphenylyl)-1,2,4-triazole (abbreviation: p-EtTAZ), Sophenanthroline (abbreviated as BPhen), Bathocuproine (abbreviated as BCP), 4,4 '-Bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs) Which heteroaromatic compound, 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo 2-[3'-(dibenzo[f,h]quinoxaline] (abbreviation: 2mDBTPDBq-II) [4-( ... Name: 2mDBTBPDBq-II), 2-[4-(3,6-diphenyl-9H-carbazo (9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq- III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h] Quinoxaline (abbreviation: 7mDBTPDBq-II), 6-[3-(dibenzothiophene- 4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-I I) or a quinoxaline or dibenzoquinoxaline derivative can be used.

[0218] In addition, poly(2,5-pyridinediyl) (abbreviation: PPy), poly[(9,9-dihexyl fluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviation: PF- Py), poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2' -bipyridine-6,6'-diyl)] (abbreviation: PF-BPy) You can also be there.

[0219] The electron transport layer 124 may be not only a single layer, but also a laminate of two or more layers made of the above-mentioned materials. The structure may be as follows.

[0220] <Electron injection layer> The electron injection layer 125 is a layer containing a substance with high electron injection properties. Lithium fluoride (LiF), Cesium fluoride (CsF), Calcium fluoride (CaF2), Lithium oxide (LiO x ) and the like, alkali metals, alkaline earth metals, or Compounds such as erbium fluoride (ErF3) can also be used. Alternatively, an electride may be used for the electron injection layer 125. For example, an electride is a mixed oxide of calcium and aluminum with electrons added. The above-mentioned material constituting the electron transport layer 124 may be a material containing a high concentration of the material. It can also be used.

[0221] The electron injection layer 125 is made of a composite material obtained by mixing an organic compound and an electron donor (donor). Such composite materials are formed by electron donors generating electrons in organic compounds. Therefore, it has excellent electron injection and electron transport properties. It is preferable that the material is excellent in transporting the generated electrons. Specifically, for example, the above-mentioned electron The electron transporting material (metal complex, heteroaromatic compound, etc.) used for the transport layer 124 can be used. The electron donor may be any substance that exhibits electron donating properties to organic compounds. Specifically, alkali metals, alkaline earth metals and rare earth metals are preferred, and lithium, cesium, Examples of the elements include aluminum, magnesium, calcium, erbium, and ytterbium. Alkali metal oxides and alkaline earth metal oxides are preferred, and lithium oxide, calcium oxide, Examples of suitable cations include barium oxide and barium nitrate. It is also possible to use organic compounds such as tetrathiafulvalene (TTF). It is also possible to do so.

[0222] Note that the light-emitting element shown in this embodiment mode can be manufactured by a vacuum process such as evaporation or a spin-coil method. Solution processes such as the ink jet method and the ink jet method can be used. In this case, sputtering, ion plating, ion beam deposition, molecular beam deposition, Physical vapor deposition (PVD) methods such as vacuum deposition and chemical vapor deposition (CVD) methods can be used. In particular, the functional layers (hole injection layer, hole transport layer, light-emitting layer, electron For the transport layer, electron injection layer), deposition method (vacuum deposition method, etc.), coating method (dip coating method , die coating method, bar coating method, spin coating method, spray coating method, etc.), printing method (ink Jet printing, screen printing, offset printing, flexography It can be formed by a method such as a printing method, a gravure method, a microcontact method, etc. do.

[0223] Note that each functional layer (hole injection layer, hole transport layer, etc.) constituting the EL layer of the light-emitting element shown in this embodiment The materials for the layer (light-emitting layer, electron transport layer, electron injection layer) are not limited to the above-mentioned materials, and other materials may be used. Other materials can be used in combination as long as they fulfill the functions of each layer. Examples include high molecular weight compounds (oligomers, dendrimers, polymers, etc.), medium molecular weight compounds, compounds (compounds in the intermediate range between low molecular weight and high molecular weight: molecular weight 400-4000), inorganic compounds (quantum As the quantum dot material, a colloidal quantum dot material can be used. quantum dot materials, alloy-type quantum dot materials, core-shell-type quantum dot materials, core-type quantum dot materials Materials such as PET can be used.

[0224] This embodiment mode can be combined with other embodiment modes as appropriate.

[0225] (Embodiment 3) In this embodiment, electronic devices of one embodiment of the present invention will be described with reference to drawings.

[0226] Examples of electronic devices include television sets, computer monitors, digital Cameras, digital video cameras, digital photo frames, mobile phones (mobile phones, mobile (also called telephone equipment), portable game machines, personal digital assistants, sound reproduction devices, pachinko machines, etc. Large game consoles are an example.

[0227] The electronic devices of this embodiment have the display device of one embodiment of the present invention in their display portions, and therefore have excellent viewing angles and The display has good performance and high display quality.

[0228] The display device of one embodiment of the present invention is suitable for electronic devices in which the display portion is observed from various angles. The display device of one embodiment of the present invention can be used for electronic devices with large screens, particularly In addition, it can be suitably used in electronic devices that have both high resolution and large screen size. Furthermore, the display device of one embodiment of the present invention is suitable for a highly flexible display portion included in an electronic device. It can be used.

[0229] The display unit of the electronic device of this embodiment can display, for example, full high definition, 4K2K, 8K4K, It is possible to display images with a resolution of 16K8K or higher. The display screen size is 20 inches or more diagonally, 30 inches or more diagonally, or 50 inches diagonally. or more, 60 inches or more diagonally, or 70 inches or more diagonally.

[0230] The electronic device of one embodiment of the present invention is flexible, and therefore can be attached to the inner or outer wall of a house or a building. , or can be incorporated along curved surfaces of the interior or exterior of a vehicle.

[0231] Furthermore, the electronic device of one embodiment of the present invention may include a secondary battery and may be configured to use wireless power transmission. It is preferable that the secondary battery can be charged.

[0232] As the secondary battery, for example, a lithium polymer battery (lithium ion battery) using a gel electrolyte is used. Lithium-ion secondary batteries such as lithium polymer batteries, nickel-metal hydride batteries, nickel-cadmium batteries, organic Examples include nickel-zinc batteries, lead-acid batteries, air secondary batteries, nickel-zinc batteries, and silver-zinc batteries. .

[0233] The electronic device according to one embodiment of the present invention may include an antenna. By doing so, it is possible to display images or information on the display unit. In the case where the device has a power supply and a secondary battery, the antenna may be used for contactless power transmission.

[0234] The electronic device of this embodiment includes sensors (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, Distance, light, liquid, magnetism, temperature, chemicals, sound, time, hardness, electric field, current, voltage, power, radiation (including the ability to measure radiation, flow rate, humidity, gradient, vibration, odor or infrared) It may be possible.

[0235] The electronic device of this embodiment can have various functions. For example, Functions for displaying still images, videos, text images, etc. on the display, touch panel function, calendar - Functions to display date or time, etc., and to run various software (programs) Functions, wireless communication functions, and functions for reading programs or data recorded on recording media etc.

[0236] FIG. 9A shows an example of a television device. The television device 7100 includes a housing 710 The display unit 7000 is built into the housing 710. This shows a configuration that supports 1.

[0237] The display device of one embodiment of the present invention can be applied to the display portion 7000.

[0238] The television set 7100 shown in FIG. 9A is operated by an operation switch provided on the housing 7101. This can be done by a separate remote control 7111 or the display unit 7000. The display unit 7000 may be provided with a touch sensor, and may be operated by touching the display unit 7000 with a finger or the like. The remote control unit 7111 displays the information output from the remote control unit 7111. The remote control 7111 may have an operation key or a touch panel. The channel and volume can be controlled by the control panel, and the display unit 7000 displays You can manipulate the video.

[0239] The television device 7100 includes a receiver, a modem, and the like. It is also possible to receive general television broadcasts via wired or wireless connection via a modem. By connecting to a wired communication network, it can be transmitted in one direction (sender to receiver) or two directions. It is also possible to communicate information in two directions (between a sender and a receiver, or between receivers). do.

[0240] FIG. 9B shows an example of a notebook personal computer. The computer 7200 includes a housing 7211, a keyboard 7212, a pointing device 72 13, an external connection port 7214, etc. The display unit 7000 is incorporated in the housing 7211. It is being done.

[0241] The display device of one embodiment of the present invention can be applied to the display portion 7000.

[0242] 9(C) and (D) show an example of digital signage.

[0243] The digital signage 7300 shown in FIG. 9C includes a housing 7301, a display unit 7000, and It also has a speaker 7303, etc., and an LED lamp, an operation key (power switch, or It can have a control switch, connection terminals, various sensors, a microphone, etc. .

[0244] FIG. 9(D) shows a digital signage 7400 attached to a cylindrical pillar 7401. The digital signage 7400 has a display unit 7000 provided along the curved surface of a pillar 7401. Has.

[0245] 9C and 9D, the display device of one embodiment of the present invention is applied to the display portion 7000. It is possible.

[0246] The larger the display unit 7000, the more information can be displayed at once. The wider the part 7000, the more noticeable it is, and for example, the more effective the advertisement. Cut.

[0247] By applying a touch panel to the display unit 7000, images or videos can be displayed on the display unit 7000. It is also preferable because it not only shows route information but also allows users to operate it intuitively. When used to provide information such as traffic information, intuitive operation is required. Usability can be improved.

[0248] Also, as shown in Figure 9(C) and (D), the Digital Signage 7300 or Digital Signage The image 7400 is an information terminal device 7311 such as a smartphone owned by a user or an information It is preferable that the display unit 70 can be connected to the information terminal 7411 by wireless communication. The advertisement information displayed on 00 is displayed on the screen of the information terminal 7311 or the information terminal 7411. In addition, by operating the information terminal 7311 or the information terminal 7411, By doing so, the display on the display unit 7000 can be switched.

[0249] In addition, the digital signage 7300 or the digital signage 7400 is equipped with an information terminal 7 311 or the screen of the information terminal 7411 is used as a control means (controller) to play games. This allows an unspecified number of users to participate in the game at the same time and enjoy it. It is possible.

[0250] 10(A1), (A2), (B) to (I) show a display device having a flexible display portion 7001. 1 shows an example of a portable information terminal.

[0251] The display portion 7001 is manufactured using a display device of one embodiment of the present invention. Applies a display device with a display panel that can be bent between 0.01mm and 150mm The display unit 7001 may be provided with a touch sensor, and the display unit 7001 can be operated by touching it with a finger or the like. You can operate the mobile information terminal by touching 1.

[0252] FIG. 10(A1) is a perspective view showing an example of a portable information terminal, and FIG. 10(A2) is a perspective view showing an example of a portable information terminal. 7 is a side view showing an example of a mobile information terminal. 01, a drawer member 7502, an operation button 7503, etc.

[0253] The portable information terminal 7500 includes a flexible display unit 7 wound in a roll shape in a housing 7501. 001.

[0254] In addition, the mobile information terminal 7500 can receive video signals using a built-in control unit. The portable information terminal 7500 can display the image on the display unit 7001. The housing 7501 is also provided with a terminal section for connecting a connector, and the video signal Alternatively, the signal or power may be supplied directly from the outside via a wire.

[0255] In addition, the operation button 7503 can be used to turn the power on and off or to change the image to be displayed. In addition, in Fig. 10(A1), (A2), and (B), the mobile information terminal In this example, the operation button 7503 is arranged on the side of the terminal 7500, but the present invention is not limited to this. It may be placed on the same surface (front surface) as the display surface of the information terminal 7500 or on the back surface.

[0256] FIG. 10B shows the portable information terminal 7500 with the display portion 7001 pulled out. In this state, an image can be displayed on the display unit 7001. The display unit 7001 can be pulled out using the material 7502. 10(A1) in which the display unit 7001 is pulled out, and FIG. 10(B) in which the display unit 7001 is pulled out. For example, the portable information terminal 7500 may display different images. In this state, the rolled-up portion of the display unit 7001 is hidden, so that the mobile information The power consumption of the terminal 7500 can be reduced.

[0257] The display unit 7001 is fixed so that the display surface of the display unit 7001 is flat when the display unit 7001 is pulled out. To secure the display unit 7001 in place, a reinforcing frame may be provided on the side of the display unit 7001.

[0258] In addition to this configuration, a speaker is provided on the housing, and the sound is transmitted by the audio signal received together with the video signal. The audio may be output by the audio input.

[0259] 10(C) to 10(E) show an example of a foldable mobile information terminal. In Fig. 10(D), the In the other state, which is in the process of changing to the other state, the portable information terminal 760 in the folded state is shown in FIG. 10(E). The portable information terminal 7600 is highly portable when folded and The seamless, large display area provides excellent visibility.

[0260] The display unit 7001 is supported by three housings 7601 connected by hinges 7602. The two housings 7601 are bent via the hinge 7602, and the portable information terminal The 7600 can be reversibly transformed from an unfolded state to a folded state.

[0261] Figures 10(F) and (G) show an example of a foldable mobile information terminal. 10(G) shows the state where the display unit 7001 is folded inward. The mobile information terminal 7650 is folded so that the 001 is facing outward. The mobile information terminal 7650 has a display portion 7001 and a non-display portion 7651. When not in use, the display unit 7001 can be folded inward. It can prevent dirt or scratches.

[0262] FIG. 10(H) shows an example of a flexible portable information terminal. The portable information terminal 7700 is The device has a housing 7701 and a display portion 7001. It also has a button 7703a as an input means, 7703b, speakers 7704a and 7704b as audio output means, and an external connection port 77 05, a microphone 7706, etc. The portable information terminal 7700 may be flexible. The battery 7709 may be mounted on the display unit 70. It may be placed on top of 01.

[0263] The housing 7701, the display portion 7001, and the battery 7709 are flexible. The portable information terminal 7700 can be bent into a desired shape or twisted. For example, the display portion 7001 of the portable information terminal 7700 is Alternatively, the portable information terminal 7700 can be folded so that the outer side faces outward. The display unit 7701 and the housing 7701 can be rolled up and used. Since the mobile information terminal 7700 can be freely deformed, it can withstand being dropped. This has the advantage that it is less likely to break even when an external force is applied to it or when an unintended external force is applied.

[0264] In addition, since the portable information terminal 7700 is lightweight, the upper part of the housing 7701 can be held with a clip or the like. Or, you can fix the housing 7701 to the wall with a magnet or the like. , and can be conveniently used in a variety of situations.

[0265] FIG. 10(I) shows an example of a wristwatch-type portable information terminal. 7801, a display unit 7001, an input / output terminal 7802, an operation button 7803, etc. The housing 7801 functions as a housing. The battery 7805 can be mounted on the display unit 700. 1 or may be arranged overlapping with band 7801.

[0266] The band 7801, the display portion 7001, and the battery 7805 are flexible. The portable information terminal 7800 can be easily bent into a desired shape.

[0267] The operation button 7803 is used to set the time, turn the power on and off, and turn wireless communication on and off. It has various functions such as operation, silent mode activation and deactivation, power saving mode activation and deactivation, etc. For example, an operating system installed in the portable information terminal 7800 can The function of the operation button 7803 can also be freely set using the stem.

[0268] In addition, by touching an icon 7804 displayed on the display unit 7001 with a finger or the like, the application You can launch the application.

[0269] In addition, the mobile information terminal 7800 is capable of performing standardized short-range wireless communication. For example, by communicating with a wireless headset, hands-free operation is possible. You can also make calls.

[0270] The portable information terminal 7800 may also have an input / output terminal 7802. If you have a 02, you can exchange data directly with other information terminals via a connector. Charging can also be performed via the input / output terminal 7802. The charging operation of the mobile information terminal shown in is performed by non-contact power transmission without using input / output terminals. That's fine.

[0271] This embodiment mode can be combined with other embodiment modes as appropriate. [Example]

[0272] In this example, the structure and characteristics of a light-emitting element that can be used in a display device of one embodiment of the present invention will be described. The structures of the light-emitting element and the comparative light-emitting element described in this example are shown in FIG. The specific configuration is shown in Tables 1 and 2. The configuration of the materials used in this example is The formula is shown below.

[0273] [Table 1]

[0274] [Table 2]

[0275] [ka]

[0276] <Fabrication of Light-Emitting Device and Comparative Light-Emitting Device> The light-emitting element and the comparative light-emitting element shown in this example are formed by forming a first layer on a substrate 1900 as shown in FIG. The first electrode 1901 is formed, and an optical adjustment layer 1904 is formed on the first electrode 1901. An EL layer 1902 is formed on the optical adjustment layer 1904, and a second electrode 190 is formed on the EL layer 1902. The EL layer 1902 has a structure in which a hole injection layer 3 is formed from the first electrode 1901 side. 1911, hole transport layer 1912, light emitting layer 1913, electron transport layer 1914, electron injection layer 19 The light-emitting element 1 and the comparative light-emitting element 2 described in this example have a structure in which the light-emitting element 1 and the comparative light-emitting element 2 are sequentially stacked. The element 11 is a light-emitting element that mainly emits red light, and the light-emitting element 1(R) and the comparative The light-emitting element 2 and the comparative light-emitting element 12 emit mainly green light. These light-emitting elements are referred to as the light-emitting element 2(G) and the comparative light-emitting element 12(G), respectively. The light-emitting element 3 and the comparative light-emitting element 13 are light-emitting elements that mainly emit blue light. They are referred to as the light-emitting element 3(B) and the comparative light-emitting element 13(B), respectively.

[0277] Furthermore, a microcavity structure is applied to the light emitting device of this example. In the light-emitting element 2, the optical distance between the electrodes is adjusted to 1 / 2 wavelength. In the two comparative light-emitting elements, the optical distance between the electrodes was adjusted to one wavelength.

[0278] First, a first electrode 1901 is formed on a substrate 1900, and an optical adjustment layer is formed on the first electrode 1901. A layer 1904 was formed on the substrate 1900. A glass substrate was used as the substrate 1900. The area of ​​the optical adjustment layer 1904 is 4 mm 2 (2 mm × 2 mm). First electrode 1901 is an alloy film of silver (Ag), palladium (Pd) and copper (Cu) (Ag-Pd-Cu (APC) The APC film was formed by sputtering. The optical adjustment layer 1904 was formed by sputtering an ITSO film. In the case of Light-emitting element 1 (R), Light-emitting element 2 (G), and Light-emitting element 3 (B), The ITSO film was formed to a thickness of 10 nm, and the comparative light-emitting element 11(R) and the comparative light-emitting element 12(R) were In the case of the light-emitting element 12 (G) and the comparative light-emitting element 13 (B), the ITSO film was set to a thickness of 110 nm. In this example, the first electrode 1901 functions as an anode. The first electrode 1901 functions as a reflective electrode. The ITSO film is a transparent conductive film. is.

[0279] Here, as a pretreatment, the surface of the substrate is washed with water, baked at 200°C for 1 hour, and then UV- The treatment was carried out for 370 seconds. -4 Vacuum deposition equipment with the inside pressure reduced to about Pa The substrate was placed in the vacuum deposition chamber and vacuum baked at 170°C for 60 minutes. After this, the substrate was allowed to cool for about 30 minutes.

[0280] Next, a hole injection layer 1911 was formed on the optical adjustment layer 1904. The hole injection layer 1911 was The vacuum deposition equipment was -4 After reducing the pressure to 100 Pa, 3-[4-(9-phenanthryl)-phenanthroline PCPPn) and molybdenum oxide. By co-evaporating the above in a weight ratio of PCPPn:molybdenum oxide = 1:0.5, In the cases of the light-emitting element 1 (R), the light-emitting element 2 (G), and the comparative light-emitting element 12 (G), The hole injection layer 1911 was formed to a thickness of 7.5 nm in the light-emitting element 3(B) and the comparative light-emitting element 3(C). In the case of the element 11(R), the hole injection layer 1911 was formed to a thickness of 20 nm. In the case of the element 13(B), the hole injection layer 1911 is formed to a thickness of 17.5 nm. did.

[0281] Next, a hole transport layer 1912 was formed on the hole injection layer 1911 .

[0282] The hole transport layer 1912 of the light-emitting element 1 (R) and the light-emitting element 2 (G) is commonly N-(1,1 '-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl) PCBBi F) was vapor-deposited to a thickness of 15 nm. The layer 1912 was made of PCPPn and was vapor deposited to a thickness of 110 nm.

[0283] Holes of the comparative light-emitting element 11 (R), the comparative light-emitting element 12 (G), and the comparative light-emitting element 13 (B) The transport layer 1912 was commonly made of PCPPn and was vapor deposited to a thickness of 15 nm. The comparative light-emitting element 11 (R) and the comparative light-emitting element 12 (G) further use PCBBiF. In the case of the comparative light-emitting element 11 (R), the film thickness was set to 55 nm. ) were deposited to a film thickness of 35 nm.

[0284] Next, a light-emitting layer 1913 was formed on the hole-transporting layer 1912 .

[0285] Light-emitting element 1 (R) and comparative light-emitting element 11 (R), which are light-emitting elements that emit red light. Layer 1913 is 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl] Dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), PCBBiF , and bis{4,6-dimethyl-2-[3-(3,5-dimethylphenyl)-5-phenyl {2-pyrazinyl-κN]phenyl-κC}(2,6-dimethyl-3,5-heptanediol Onato-κ 2 O,O')iridium(III) (abbreviation: [Ir(dmdppr-P)2( dibm)]) with a weight ratio of 2mDBTBPDBq-II:PCBBiF:[Ir( dmdppr-P)2(dibm)] = 0.8:0.2:0.06 The light-emitting layer 1913 of the light-emitting element 1(R) was formed to a thickness of 75 nm. The light-emitting layer 1913 of the comparative light-emitting element 11(R) was formed to have a thickness of 70 nm.

[0286] Light-emitting element 2 (G) and comparative light-emitting element 12 (G), which are light-emitting elements that emit green light. Layer 1913 contains 2mDBTBPDBq-II, PCBBiF, and Tris(4-t-butyl) Iridium(III) (abbreviation: [Ir(tBuppm) 3]) was used, and the weight ratio was 2mDBTBPDBq-II:PCBBiF:[Ir(tBup pm)3] = 0.8:0.2:0.06, and was co-evaporated to a film thickness of 40 nm. Ta.

[0287] Light-emitting element 3(B) and comparative light-emitting element 13(B), which are light-emitting elements that emit blue light. Layer 1913 is 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzyl N,N'-(pyrene-1)-benzo[c,g]carbazole (abbreviation: cgDBCzPA) ,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan) -8-amine] (abbreviation: 1,6BnfAPrn-03) was used, and the weight ratio was cgDBCzP A:1,6BnfAPrn-03=1:0.03, co-evaporated to a film thickness of 25 nm It was formed.

[0288] The subsequent manufacturing steps are common to all light-emitting elements of this example.

[0289] Next, an electron transport layer 1914 was formed on the light emitting layer 1913. The electron transport layer 1914 was 2 m thick. The thickness of DBTBPDBq-II is 10 nm, and 2,9-bis(naphthalen-2-yl)-4 ,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen) film thickness is 10n The layers were deposited in order so that the thickness of the layers was m.

[0290] Next, an electron injection layer 1915 was formed on the electron transport layer 1914. The electron injection layer 1915 was The film was formed by vapor deposition using lithium fluoride (LiF) to a thickness of 1 nm.

[0291] Next, the second electrode 1903 was formed on the electron injection layer 1915. The second electrode 1903 was The volume ratio of silver (Ag) to magnesium (Mg) is 1:0.1, and the film thickness is 25 nm. After forming the layer by co-evaporation as shown above, indium tin oxide (ITO) was deposited by sputtering. In this example, the second electrode 1903 was formed to a thickness of 70 nm. The second electrode 1903 functions as a cathode. It is a semi-transparent and semi-reflective electrode that has the function of

[0292] By the above steps, a light emitting element was formed on the substrate 1900. A hole injection layer 1911, a hole transport layer 1912, a light emitting layer 1913, an electron transport layer 1914, and an electrode The electron injection layer 1915 is a functional layer that constitutes the EL layer in one embodiment of the present invention. In the deposition steps in the above-described manufacturing method, deposition by resistance heating was used in all cases.

[0293] The light emitting device manufactured in this example is sealed by a substrate 1900 and a sealing substrate. The substrate 1900 and the sealing substrate are sealed with a sealing material in a glove box under a nitrogen atmosphere. The sealing substrate is fixed on the substrate 1900 using a sealing material, and the periphery of the light emitting element formed on the substrate 1900 is A sealant was applied to the enclosure, and 365 nm ultraviolet light was applied at 6 J / cm during sealing. 2 Irradiated and at 80°C This was done by heat treatment for 1 hour.

[0294] In addition, all of the light-emitting elements manufactured in this example were formed from the second electrode 1903 side of the light-emitting element. The structure is such that light is emitted in the direction of the arrow (Figure 11).

[0295] <Chromaticity of light-emitting element> Next, each light-emitting device fabricated in this example was subjected to a current of 2.5 mA / cm 2 When a current is applied at a current density of The emission spectrum was measured using a multi-channel spectrometer (Hamamatsu The emission spectrum of the light-emitting element 1 (R) was 63 The emission spectrum of Light-emitting element 2 (G) is around 523 nm, and that of Light-emitting element 3 (B) is around 523 nm. The emission spectrum is around 460 nm, and the emission spectrum of the comparative light-emitting element 11(R) is around 633 nm. The emission spectrum of comparative light-emitting element 12(G) is around 523 nm, and the emission spectrum of comparative light-emitting element 13 The emission spectrum of (B) had a peak around 459 nm.

[0296] Next, the CIE1931 chromaticity coordinates (xy chromaticity coordinates) of each light-emitting element manufactured in this example were The chromaticity (x, y) of the light was measured using a color luminance meter (Topcon, BM-5AS). The results are shown in Table 3. Light-emitting element 1 (R) has a luminance of 1281 cd / m 2 , Light-emitting element 2 (G) is 3337 cd / m 2 , and light-emitting element 3 (B) is 283 cd / m 2 , and the comparative light-emitting element 11(R) is 1468 cd / m 2 , and the comparative light-emitting element 12 (G) is 4329 cd / m 2 , Comparative Light-Emitting Element 13(B) 310cd / m 2 is the chromaticity at the luminance of

[0297] [Table 3]

[0298] From the above results, the chromaticity of the light-emitting element 1 (R) in this example is such that the chromaticity x is greater than 0.680. The chromaticity y is greater than or equal to 0.720 and is greater than or equal to 0.260 and less than or equal to 0.320. G) chromaticity is chromaticity x is 0.130 or more and 0.250 or less, chromaticity y is 0.710 or more, The chromaticity of light-emitting element 3 (B) satisfies the condition that the chromaticity x is 0.120 or more and 0.17 0 or less, and the chromaticity y is in the range of 0.020 or more and less than 0.060. ) is different from the DCI-P3 standard because the chromaticity x is greater than 0.680. It can be seen that the red chromaticity is also good. For light-emitting element 2 (G), the chromaticity y is 0.71 Because it is greater than 0, the green chromaticity is better than the DCI-P3 standard and the NTSC standard. Furthermore, for the light-emitting element 3(B), the chromaticity y is particularly low when it is less than 0.060. This shows that the blue chromaticity is better than the DCI-P3 standard.

[0299] The chromaticity (x, y) of each light-emitting element obtained here is expressed as CIE1931 chromaticity coordinates (xy color The chromaticity is expressed in degrees (deg. coordinates), but the perceived chromaticity can be expressed by the following conversion formula (1): The CIE 1976 chromaticity was established with the intention that the color differences correspond to equal distances in space. It can also be expressed in coordinates (u'v' chromaticity coordinates).

[0300]

number

[0301] In the light-emitting element of this example, in CIE1976 chromaticity coordinates (u'v' chromaticity coordinates), The chromaticity of the BT.2020 is shown in Table 4 below. For comparison, Table 5 shows the chromaticity of the BT.2020 The standard chromaticity coordinates are shown below.

[0302] [Table 4]

[0303] [Table 5]

[0304] Based on the results in Table 4, the chromaticity (u', v') for BT.2020 was calculated. The area ratio was 94%, and the coverage rate of BT.2020 was 92%. The triangle formed by connecting the CIE chromaticity coordinates (u', v') of the RGB of the 2020 standard The area A is formed by connecting the CIE chromaticity coordinates (u', v') of the three light-emitting elements of this embodiment. The area B of each triangle is calculated, and the area ratio (B / A) is calculated. The coverage rate is the percentage of the BT.2020 standard color gamut (inside the triangle above) that is covered by this implementation. This shows what can be reproduced by combining the chromaticities of the three light-emitting elements.

[0305] <Viewing angle dependence of chromaticity and brightness of light-emitting elements> Next, the viewing angle dependency of the chromaticity and luminance of the light-emitting element fabricated in this example was calculated.

[0306] First, the emission spectrum of the light emitting element in the front direction and the emission spectrum in the oblique direction were measured. Specifically, the direction perpendicular to the light-emitting surface of the light-emitting element is set to 0°, and the angle is measured from -80° to 80° in 10° increments. The emission spectrum was measured at 17 points every 100°. From the measurement results, the light-emitting element at each angle The luminance, chromaticity (x, y), and chromaticity (u', v') of the child were obtained.

[0307] Next, light-emitting element 1 (R), light-emitting element 2 (G), and light-emitting element 3 (B) were used to generate white light (D6 5, 300 cd / m 2 ) is expressed as the luminance of each light-emitting element when displaying the chromaticity (x, y) (hereinafter also referred to as front chromaticity). The luminance was determined as the front luminance of each light-emitting element. Similarly, comparative light-emitting element 11 (R), comparative light-emitting element 12 (G), and comparative light-emitting element 13 (B ) using white (D65, 300 cd / m 2 ) when the brightness of each comparative light-emitting element is displayed. The luminance was determined as the front luminance of each comparative light-emitting element.

[0308] Next, the luminance ratio between the front luminance and the luminance at each angle was calculated. The luminous intensity ratio at each angle was calculated based on the standard angle of 100°, and this luminous intensity ratio was used as the brightness ratio. .

[0309] The luminance at each angle was calculated by multiplying the front luminance by the luminance ratio. The chromaticity of white at each angle was calculated from the above. The case where the light-emitting element 3(B) is used is defined as white display condition 1, and the comparative light-emitting element 11(R), the comparative The case where the light-emitting element 12 (G) and the comparative light-emitting element 13 (B) are used is defined as white display comparative condition 2. I will explain.

[0310] ≪White display condition 1≫ When light-emitting element 1 (R), light-emitting element 2 (G), and light-emitting element 3 (B) are used to display white light, The viewing angle dependence of chromaticity in this case is shown in FIGS. 12 and 13. Element 2 (G), light-emitting element 3 (B), and displaying white using these three light-emitting elements Similarly, FIG. 13 shows the chromaticity (x, y) of the light-emitting element 1 (R ), light-emitting element 2 (G), light-emitting element 3 (B), and white light produced by using these three light-emitting elements. When displaying (W), the chromaticity (u', v') in the CIE1976 chromaticity coordinates at each angle ) is shown.

[0311] FIG. 16 shows a front view of the light-emitting element 1 (R), the light-emitting element 2 (G), and the light-emitting element 3 (B). The relative brightness at each angle is shown with the brightness as the standard. In Figure 16, the brightness at 0° is set to 1. Also, in FIG. 17, light-emitting element 1 (R), light-emitting element 2 (G), light-emitting element 3 (B), and When these three light-emitting elements are used to display white (W), the CIE 1976 chromaticity coordinates are: The chromaticity difference Δu'v' between the front chromaticity and the chromaticity at each angle is shown.

[0312] ≪White display comparison condition 2≫ Comparative light-emitting element 11 (R), comparative light-emitting element 12 (G), and comparative light-emitting element 13 (B) were used. The viewing angle dependence of chromaticity when displaying white is shown in Figures 14 and 15. Light-emitting element 11 (R), comparative light-emitting element 12 (G), comparative light-emitting element 13 (B), and Chromaticity (x, y) at each angle when displaying white (W) using three comparative light-emitting elements Similarly, FIG. 15 shows comparative light-emitting element 11 (R), comparative light-emitting element 12 (G), When white light is displayed using the optical element 13 (B) and these three comparative light-emitting elements (W) The chromaticity (u', v') at each angle is shown.

[0313] 18 shows comparative light-emitting element 11(R), comparative light-emitting element 12(G), and comparative light-emitting element 13(B) shows the relative luminance at each angle, with the front luminance as the reference. The luminance at this time was set to 1. In addition, FIG. 19 shows the luminance of the comparative light-emitting element 11 (R) and the comparative light-emitting element 12 (G). ), comparative light-emitting element 13(B), and a case where white is displayed using these three comparative light-emitting elements. In the case of (W), the chromaticity difference Δ between the front chromaticity and the chromaticity at each angle in the CIE1976 chromaticity coordinates Indicates u'v'.

[0314] From these results, it can be seen that the light-emitting elements of each color (RGB) used in the white display condition 1 are Compared to the comparative light-emitting element of the same color used in 2, the viewing angle dependency is small and it is good even from an oblique angle. It was found that a good light emission state was obtained. It was found that this suppresses the color shift of white (W) due to angle.

[0315] Specifically, in a comparison between FIG. 12 and FIG. 14 and a comparison between FIG. 13 and FIG. 15, under white display condition 1 The light-emitting elements of each color (RGB) used in the comparison were the same color light-emitting elements used in the comparison condition 2 for white display. The change in chromaticity due to the angle was smaller than that in the white display condition 1. Compared to the above, the chromaticity change of white (W) due to the angle was small.

[0316] Also, comparing Figure 16 and Figure 18, under white display condition 1 (Figure 16), the angle is 30° or more and 60° or more. In the lower range, the relative luminance of the light-emitting element 1 (R) is higher than the relative luminance of the light-emitting element 3 (B), A similar tendency was observed in the range of -60° to -30°. In FIG. 18, at an angle of 30°, the relative luminance of comparative light-emitting element 11(R) is higher than that of comparative light-emitting element 13 (B) is higher than the relative luminance of (A), but as the angle becomes larger, the magnitude relationship is reversed. In this case, the relative luminance of the comparative light-emitting element 11 (R) is lower than the relative luminance of the comparative light-emitting element 13 (B). A similar reversal of the magnitude relationship was confirmed in the range of -60° to -30°. As in comparison condition 2, when the RGB luminance ratio changes depending on the angle, the chromaticity of white changes significantly. In the white display condition 1, the red light emitting element and the green light emitting element are more sensitive than in the white display comparison condition 2. The luminance decay rate of the light-emitting element is small. Therefore, under white display condition 1, the phase of the two colors changes depending on the angle. The magnitude relationship of the luminance is not reversed. This suppresses the change in white chromaticity due to the angle. It is possible.

[0317] 17 and 19, the chromaticity difference Δu′v′ of the comparative light-emitting element 11 (R) is 5 It was over 0.05 in the range of 0° to 80° and in the range of -80° to -50°. In contrast, the chromaticity difference Δu'v' of the light-emitting element 1 (R) is 0.0 at any angle. The result was that the chromaticity difference Δu'v' between the oblique chromaticity and the front chromaticity was small. Also, as shown in Figure 17, under white display condition 1, the chromaticity difference Δu'v' of all RGBW The chromaticity at any angle is less than 0.05, and the chromaticity at the oblique direction and the front chromaticity are The results showed that the difference Δu'v' was small.

[0318] In the white display condition 1 and the white display comparison condition 2, the thickness of the red light-emitting element and the thickness of the blue light-emitting element The magnitude relationship (specifically, the magnitude relationship of the distance between the electrodes) is different. The thickness of the light-emitting element 3(B) is thicker than the thickness of the light-emitting element 1(R). The comparative light emitting element 13(B) is thinner than the comparative light emitting element 11(R).

[0319] In this example, a microcavity structure is used in each light-emitting element to improve the color purity of each light emission. Under the white display comparison condition 2, the thickness of the three comparative RGB light-emitting elements was set to the optical distance between the electrodes. On the other hand, in the white display condition 1, the thickness of the light-emitting element 3(B) is The optical distance between the electrodes is determined to be one wavelength, and the thickness of light-emitting element 1 (R) and light-emitting element 2 (G) is The length was determined so that the optical distance between the electrodes was 1 / 2 wavelength. In particular, the viewing angle dependence of the white chromaticity was reduced. By determining the optical distance to be λ / 2, the angle-dependent This suppresses the change in chromaticity and the attenuation of brightness. As a result, the viewing angle dependency of white chromaticity is also reduced. I was able to do it.

[0320] In this example, light-emitting elements that emit red, green, and blue light were fabricated. The light-emitting elements have light-emitting layers made of different materials, and the light path length can be adjusted by On the other hand, these light-emitting devices have hole transport layers with different thicknesses. The electron injection layer and the electron injection layer are formed with the same material and the same thickness, and each layer is formed with a different composition. This combination reduces the number of processes compared to when using a single light-emitting element. Even though the EL layer has many layers with a common configuration, it is possible to obtain a wide range of color reproducibility and good viewing angle characteristics. In this example, the hole injection layer was formed to a different thickness for each color. The hole injection layers of the optical elements may be provided with the same thickness.

[0321] From the above results, it can be seen that the use of the light-emitting element shown in this example provides a wide viewing angle and a wide color gamut. It was found that it was possible to fabricate a display device capable of displaying [Example]

[0322] In this example, the structure and characteristics of a light-emitting element that can be used in a display device of one embodiment of the present invention will be described. The structure of the light-emitting device explained in this example is shown in FIG. The structural formulas of the materials used in this example are shown below. Materials that have been used will be omitted.

[0323] [Table 6]

[0324] [ka]

[0325] <Fabrication of light-emitting device> The light-emitting element 4 described in this example is a light-emitting element that mainly emits red light. The light-emitting element 5 is a light-emitting element that mainly emits green light, and is shown as light-emitting element 5( The light-emitting element 6 is a light-emitting element that mainly emits blue light, and is shown as light-emitting element 6( B).

[0326] Furthermore, a microcavity structure is applied to the light-emitting device of this example. In the light-emitting element 5, the optical distance between the electrodes is adjusted to 1 / 2 wavelength, and in the light-emitting element 6, was adjusted so that the optical distance between the electrodes was one wavelength.

[0327] The light-emitting element 4(R) has the same structure as the light-emitting element 1(R) of Example 1 except for the hole injection layer 1911. The light-emitting element 5(G) was fabricated in the same manner as the light-emitting element 2(G) of Example 1 except for the hole injection layer 1911. The light-emitting element 6(B) was fabricated in the same manner as in the light-emitting element 6(A). Other than that, the light-emitting device was fabricated in the same manner as the light-emitting device 3(B) of Example 1. Only the differences will be detailed.

[0328] The hole injection layer 1911 of the light-emitting element 4(R), the light-emitting element 5(G), and the light-emitting element 6(B) is In common, the vacuum deposition equipment was -4 After reducing the pressure to 100 Pa, 9-phenyl-3-[4-(1 0-Phenyl-9-anthrylphenyl]-9H-carbazole (abbreviation: PCzPA) and molybdenum oxide were mixed in a weight ratio of PCzPA:molybdenum oxide=1:0.5. The hole injection layer 1911 was formed by co-evaporation with the Formed.

[0329] The hole transport layer 1912 of the light-emitting element 6(B) is made of PCzPA and has a film thickness of 110 nm. It was evaporated like this.

[0330] In addition, all of the light-emitting elements manufactured in this example were formed from the second electrode 1903 side of the light-emitting element. The structure is such that light is emitted in the direction of the arrow (Figure 11).

[0331] <Chromaticity of light-emitting element> Next, each light-emitting device fabricated in this example was subjected to a current of 2.5 mA / cm 2 When a current is applied at a current density of The emission spectrum was measured using a multi-channel spectrometer (Hamamatsu The emission spectrum of the light-emitting element 4 (R) was measured using a 63 The emission spectrum of Light-emitting element 5 (G) is around 525 nm, and that of Light-emitting element 6 (B) is around 535 nm. The emission spectrum had a peak around 458 nm.

[0332] Next, the CIE1931 chromaticity coordinates (xy chromaticity coordinates) of each light-emitting element manufactured in this example were The chromaticity (x, y) of the light was measured using a color luminance meter (Topcon, BM-5AS). The results are shown in Table 7. Light-emitting element 4 (R) has a luminance of 1308 cd / m 2 , Light-emitting element 5 (G) is 4392 cd / m 2 , and light-emitting element 6 (B) is 264 cd / m 2 is the chromaticity at the luminance of

[0333] [Table 7]

[0334] From the above results, the chromaticity of the light-emitting element 4 (R) in this example is such that the chromaticity x is greater than 0.680. The chromaticity y is greater than or equal to 0.720 and is greater than or equal to 0.260 and less than or equal to 0.320. G) chromaticity is chromaticity x is 0.130 or more and 0.250 or less, chromaticity y is 0.710 or more, The chromaticity of the light-emitting element 6(B) satisfies the condition that the chromaticity x is 0.120 or more and 0.17 0 or less, and the chromaticity y is in the range of 0.020 or more and less than 0.060. ) is different from the DCI-P3 standard because the chromaticity x is greater than 0.680. It can be seen that the red chromaticity is also good. For the light-emitting element 5 (G), the chromaticity y is 0.71 Because it is greater than 0, the green chromaticity is better than the DCI-P3 standard and the NTSC standard. Furthermore, for the light-emitting element 6(B), the chromaticity y is particularly low when it is less than 0.060. This shows that the blue chromaticity is better than the DCI-P3 standard.

[0335] In the light-emitting element of this example, in CIE1976 chromaticity coordinates (u'v' chromaticity coordinates), The chromaticity is as shown in Table 8 below.

[0336] [Table 8]

[0337] Based on the results of Table 8, the chromaticity (u', v') for BT.2020 was calculated. The area ratio was 100% and the BT.2020 coverage rate was 92%.

[0338] The viewing angle dependence of the chromaticity and luminance of the light-emitting element is affected by the film thickness of the light-emitting element. The film thickness of the light emitting device of Example 2 is the same as that of the light emitting device of Example 1. Even when the light emitting element is used, the viewing angle is wide and the color gamut is wide, similar to when the light emitting element of Example 1 is used. This suggests that it is possible to fabricate a display device capable of displaying at 1000 Hz.

[0339] <Initial characteristics of light-emitting element> The initial characteristics of the light-emitting element 4(R) are almost the same as those of the light-emitting element 1(R) in Example 1. The light-emitting element 4(R) has the same organic materials as the light-emitting element 1(R) except for the organic materials used in the hole injection layer 1911. ), it is thought that there was little effect on the initial characteristics.

[0340] The initial characteristics of the light-emitting element 5 (G) are almost the same as those of the light-emitting element 2 (G) in Example 1. The light-emitting element 5(G) also has the same organic material as the light-emitting element 2(G) except for the organic material used for the hole injection layer 1911. ), it is thought that there was little effect on the initial characteristics.

[0341] Next, the current-voltage characteristics of the light-emitting element 6(B) are shown in Fig. 20. In Fig. 20, the vertical axis represents the current The horizontal axis represents the voltage (V) and the horizontal axis represents the current (mA). The current-voltage characteristics of optical element 3(B) are also shown.

[0342] As shown in FIG. 20, the light-emitting element 6(B) has a current-voltage characteristic shorter than that of the light-emitting element 3(B). It was found that the device was excellent in performance and could be driven at a low voltage.

[0343] The light-emitting element 6(B) includes an organic material for the hole injection layer 1911 and an organic material for the hole transport layer 191 The material of the hole transport layer 1912 is also different from that of the light-emitting element 3(B). The driving voltage may increase. By changing the material, the driving voltage could be reduced compared to that of the light-emitting element 3(B).

[0344] <Reliability of light-emitting element> Next, the light-emitting element 1 (R), the light-emitting element 2 (G), and the light-emitting element 3 (B) of Example 1, Reliability tests of the light-emitting elements 4(R), 5(G), and 6(B) of this example The results are shown in Figure 21. In Figure 21, the vertical axis represents the normalized luminance when the initial luminance is 100%. The horizontal axis shows the degree of reliability (%), and the horizontal axis shows the device operation time (h). The current value of each light-emitting element is set assuming display with the chromaticity of light source D65, and each light-emitting element is driven. The current value of light-emitting element 1 (R) was 0.128 mA, and the current value of light-emitting element 2 (G) was 0.17 The current value for light-emitting element 3 (B) was 0.6mA, the current value for light-emitting element 4 (R) was 0.328mA, and the current value for light-emitting element 4 (R) was 0. The current value of light-emitting element 5 (G) is 128mA, the current value of light-emitting element 6 (B) is 0.155mA. It was set to 0.389mA.

[0345] In FIG. 21, the luminance degradation curves of the light-emitting element 1(R) and the light-emitting element 4(R) almost overlap. Furthermore, the luminance deterioration curves of the light-emitting element 2(G) and the light-emitting element 5(G) were almost overlapped. As shown above, changing the organic material used in the hole injection layer 1911 has almost no effect on reliability. Furthermore, the initial deterioration of the light-emitting element 6(B) was smaller than that of the light-emitting element 3(B). It was revealed that the material has a long life.

[0346] In this example, light-emitting elements that emit red, green, and blue light were fabricated. The light-emitting elements have light-emitting layers made of different materials, and the light path length can be adjusted by On the other hand, these light-emitting devices have hole injection layers. The electron transport layer and the electron injection layer are formed of the same material and have the same thickness, and each layer is different. This is a combination that can reduce the number of processes compared to forming it with three structures. The light-emitting element of this material has a wide range of color reproducibility even though it has many layers with a common configuration in the EL layer. .

[0347] Furthermore, in this embodiment, the organic material used for the hole injection layer 1911 and By changing the material used in the hole transport layer 1912 of the light-emitting element that emits blue light, it is possible to obtain a light-emitting element that emits red light. The present invention provides a light-emitting element that emits blue light and a light-emitting element that emits green light, while maintaining the initial characteristics and reliability of the light-emitting element that emits blue light and the light-emitting element that emits green light. It has been possible to reduce the driving voltage of the light-emitting element that emits color light and improve its reliability. [Example]

[0348] In this example, the structure and characteristics of a light-emitting element that can be used in a display device of one embodiment of the present invention will be described. The structure of the light-emitting device explained in this example is shown in FIG. The structural formulas of all the materials used in this example are shown in Tables 9 and 10. It is a material.

[0349] [Table 9]

[0350] [Table 10]

[0351] <Fabrication of light-emitting device> The light-emitting element 7 described in this example is a light-emitting element that mainly emits red light. The light-emitting element 8 is a light-emitting element that mainly emits green light, and is shown as light-emitting element 8( The light-emitting element 9 is a light-emitting element that mainly emits blue light, and is shown as light-emitting element 9( B).

[0352] The light emitting element of this example has a microcavity structure. In the optical element 8, the optical distance between the electrodes is adjusted to 1 / 2 wavelength. The optical distance between the poles was adjusted to be one wavelength.

[0353] As shown in Tables 9 and 10, the thickness (V) of the hole injection layer 1911 of the light-emitting element 7 (R) and the The thickness (W) of the hole injection layer 1911 of the light-emitting element 8 (G) and the thickness (W) of the hole injection layer 1911 of the light-emitting element 9 (B) There are eight combinations of the thickness (X) of 911 and the thickness of the three light-emitting elements. The layer formed by co-evaporating Ag and Mg (hereinafter referred to as the Ag:Mg layer) of the second electrode 1903 From the above, there are three types of thickness (Y) of the light emitting element 7 (R) and the light emitting element 8 ( There are 24 combinations of the light emitting element 9(G) and the light emitting element 9(B).

[0354] In this embodiment, light emitting elements 7(R), 8(G), and 9(B) are used to generate white light. The power consumption, color gamut, and color shift when displaying colors were evaluated. The color gamut was CIE 1976 colors. The area ratio to BT.2020 calculated from the chromaticity in chromaticity coordinates (u'v' chromaticity coordinates) The color shift was evaluated by the chromaticity difference Δu' between the front chromaticity and the chromaticity at a 60° angle from the front. It was evaluated by v'.

[0355] Figures 22(A), (B), and (C) show the evaluation of power consumption, color gamut, and color shift for each combination. 22(A) and (B), as the thickness Y of the Ag:Mg layer increases, Although the power consumption increases, the color gamut becomes wider. Even with the misalignment, the chromaticity difference Δ between the front chromaticity and the chromaticity at a 60° angle from the front The u'v' is generally kept below 0.05, demonstrating that the effect of one aspect of the present invention is obtained. I found out that... [Explanation of symbols]

[0356] 10A display device 10B Display device 22 Multi-display 23 Display area 28 Adhesive layer 29 Circuit Board 31 Insulating layer 32 Insulating layer 33 Insulating layer 34 Insulating layer 35 Insulating layer 40 transistors 41 Conductive layer 42 Semiconductor layer 42a Channel region 42b Low resistance region 43a Conductive layer 43b Conductive layer 43c conductive layer 45 Conductive layer 46 Insulating layer 49 Transistors 60 Light-emitting element 74 Insulating layer 75 Protective layer 75a board 75b Adhesive layer 76 Connectors 100 display device 100a display device 100b display device 100c display device 100d display device 101 Display area 101a Display area 101b Display area 101c display area 101d Display area 102 areas 109a FPC 110 Transparent conductive film 110B Optical adjustment layer 110G optical adjustment layer 110R optical adjustment layer 110Y optical adjustment layer 111 first electrode 111a Conductive film 112 Second electrode 113B EL layer 113G EL layer 113R EL layer 113Y EL layer 115B Light-emitting element 115G light emitting element 115R light emitting element 115Y light-emitting element 116B Light 116G luminous 116R luminous 116Y luminescence 118B resist film 118G resist film 118R resist film 119 Visible light transmitting area 119b Area that transmits visible light 119c Area that transmits visible light 119d Area that transmits visible light 120 Visible light blocking area 121 Hole injection layer 122 Hole transport layer 122B Hole transport layer 122G Hole transport layer 122R hole transport layer 123B Light-emitting layer 123G Light-emitting layer 123R luminescent layer 124 Electron transport layer 125 Electron injection layer 131 Circuit Board 132 PCB 133B Light-emitting element 133G Light-emitting element 133R light-emitting element 134 Space 135 transistors 136 Insulating Layer 137 Adhesive layer 372 FPC 381 Display section 382 Drive circuit section 1900 board 1901 First electrode 1902 EL layer 1903 Second electrode 1904 Optical adjustment layer 1911 Hole injection layer 1912 Hole transport layer 1913 luminescent layer 1914 Electron transport layer 1915 Electron injection layer 7000 Display 7001 Display section 7100 Television equipment 7101 Housing 7103 Stand 7111 Remote control device 7200 Notebook Personal Computer 7211 Case 7212 keyboard 7213 Pointing Device 7214 External connection port 7300 Digital Signage 7301 Housing 7303 Speaker 7311 Information terminals 7400 Digital Signage 7401 Pillar 7411 Information terminals 7500 Mobile Information Terminal 7501 Case 7502 Materials 7503 Operation button 7600 Personal Digital Assistant 7601 Case 7602 Hinge 7650 Personal Digital Assistant 7651 Hidden part 7700 Personal Digital Assistant 7701 Housing 7703a Button 7703b Button 7704a Speaker 7704b Speaker 7705 External connection port 7706 Mike 7709 Battery 7800 Mobile Information Terminal 7801 band 7802 Input / output terminal 7803 Operation button 7804 Icons 7805 Battery

Claims

[Claim 1] Each of the first light-emitting element, the second light-emitting element, and the third light-emitting element has a pair of electrodes and a light-emitting layer between the pair of electrodes, one of the pair of electrodes has a reflective electrode, the other of the pair of electrodes has a semi-transmissive and semi-reflective electrode, the first light-emitting element, the second light-emitting element, and the third light-emitting element each have a different light-emitting layer; a first peak wavelength of an emission spectrum of the first light-emitting element is 400 nm or more and 480 nm or less; a second peak wavelength of the emission spectrum of the second light-emitting element is 580 nm or more and 700 nm or less; a third peak wavelength of the emission spectrum of the third light-emitting element is a wavelength between the first peak wavelength and the second peak wavelength; a distance between the pair of electrodes of the first light-emitting element is longer than a distance between the pair of electrodes of the second light-emitting element; a distance between the pair of electrodes of the second light-emitting element is longer than a distance between the pair of electrodes of the third light-emitting element; a thickness of the hole transport layer of the first light-emitting element is larger than a thickness of the hole transport layer of the second light-emitting element and a thickness of the hole transport layer of the third light-emitting element; The hole transport layer of the second light emitting element and the hole transport layer of the third light emitting element have the same film thickness.

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