Display device

Abstract

To provide a display device with high display quality.SOLUTION: A display device has a first light-emitting device and a second light-emitting device. The first light-emitting device and the second light-emitting device each have a common electrode with a light-transmitting property. The first light-emitting device has a first electrode, a first EL layer, and a first auxiliary electrode with a light-transmitting property. The second light-emitting device has a second electrode, a second EL layer, and a second auxiliary electrode with a light-transmitting property. The first EL layer is located between the first electrode and the common electrode. The second EL layer is located between the second electrode and the common electrode. The first auxiliary electrode is located between the first EL layer and the common electrode. The second auxiliary electrode is located between the second EL layer and the common electrode. A film thickness of the first auxiliary electrode is larger than that of the second auxiliary electrode.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] One embodiment of the present invention relates to a display device. Note that one embodiment of the present invention is not limited to the above technical field. Examples of the technical field of one embodiment of the present invention disclosed in this specification and the like include a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, an electronic device, a lighting device, an input device, an input / output device, a driving method thereof, or a manufacturing method thereof. A semiconductor device refers to any device that can function by utilizing semiconductor characteristics. [Background technology]

[0002] In recent years, there has been a demand for higher definition display panels. Examples of devices that require high-definition display panels include smartphones, tablet terminals, and notebook computers. In addition, stationary display devices such as television devices and monitor devices are also required to have higher definition in line with the increase in resolution. Furthermore, devices that require the highest definition include devices for virtual reality (VR) or augmented reality (AR).

[0003] Representative examples of display devices that can be used as display panels include liquid crystal display devices, organic EL (Electro Luminescence) elements, light-emitting devices equipped with light-emitting devices such as light-emitting diodes (LEDs), and electronic paper that displays images using an electrophoretic method.

[0004] For example, the basic structure of an organic EL element is a layer containing a light-emitting organic compound sandwiched between a pair of electrodes. By applying a voltage to this element, light can be emitted from the light-emitting organic compound. A display device using such an organic EL element does not require a backlight, which is necessary for liquid crystal display devices and the like, and therefore a thin, lightweight, high-contrast, and low-power display device can be realized.

[0005] There are various known methods for manufacturing organic EL elements, and a manufacturing method for forming an organic compound layer by an inkjet method has been disclosed (Patent Document 1). The organic EL element formed by the manufacturing method described in Patent Document 1 has an optical adjustment layer, and optical adjustment is performed. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2022-80879 A Summary of the Invention [Problem to be solved by the invention]

[0007] In the manufacturing method disclosed in Patent Document 1, after forming each organic compound layer by an inkjet method, a common optical adjustment layer is provided for each organic EL element, which poses a problem that it is difficult to perform an optimal optical design for each organic EL element.

[0008] An object of one embodiment of the present invention is to provide a display device with high display quality.An object of one embodiment of the present invention is to provide a display device with low power consumption.An object of one embodiment of the present invention is to provide a display device which can easily be made high-definition.An object of one embodiment of the present invention is to provide a display device which has both high display quality and high definition.An object of one embodiment of the present invention is to provide a display device with high contrast.

[0009] An object of one embodiment of the present invention is to provide a display device having a novel structure or a manufacturing method of the display device.An object of one embodiment of the present invention is to provide a method for manufacturing the above-described display device with high yield.An object of one embodiment of the present invention is to alleviate at least one of the problems of the prior art.

[0010] Note that the description of these problems does not preclude the existence of other problems. Note that one embodiment of the present invention does not necessarily solve all of these problems. Note that problems other than these can be extracted from the description of the specification, drawings, claims, etc. [Means for solving the problem]

[0011] One embodiment of the present invention is a display device including a first light-emitting device and a second light-emitting device, the first light-emitting device and the second light-emitting device having a light-transmitting common electrode, the first light-emitting device having a first electrode, a first EL layer, and a first auxiliary electrode having light-transmitting properties, the second light-emitting device having a second electrode, a second EL layer, and a second auxiliary electrode having light-transmitting properties, the first EL layer is located between the first electrode and the common electrode, the second EL layer is located between the second electrode and the common electrode, the first auxiliary electrode is located between the first EL layer and the common electrode, and the second auxiliary electrode is located between the second EL layer and the common electrode, and the first auxiliary electrode is thicker than the second auxiliary electrode.

[0012] Another embodiment of the present invention is a display device including a first light-emitting device and a second light-emitting device. The first light-emitting device and the second light-emitting device have a light-transmitting common electrode. The first light-emitting device has a first electrode, a first EL layer, and a light-transmitting first auxiliary electrode. The second light-emitting device has a second electrode and a second EL layer. The first EL layer is located between the first electrode and the common electrode. The second EL layer is located between the second electrode and the common electrode and in contact with the common electrode. The first auxiliary electrode is located between the first EL layer and the common electrode.

[0013] Another embodiment of the present invention is a display device including a first light-emitting device and a second light-emitting device, the first light-emitting device and the second light-emitting device having a common layer and a light-transmitting common electrode, the common electrode being located on the common layer, the first light-emitting device having a first electrode, a first EL layer, and a light-transmitting first auxiliary electrode, the second light-emitting device having a second electrode and a second EL layer, the first EL layer being located between the first electrode and the common layer, the second EL layer being located between the second electrode and the common layer and in contact with the common layer, and the first auxiliary electrode being located between the first EL layer and the common layer.

[0014] In the display device having the above configuration, the common layer more preferably contains an alkali metal or an alkaline earth metal.

[0015] Another embodiment of the present invention is a display device having any of the above structures, in which the emission color of the first light-emitting device is different from the emission color of the second light-emitting device.

[0016] Another embodiment of the present invention is a display device having any of the above structures, in which light emitted from the first light-emitting device has a longer wavelength than light emitted from the second light-emitting device.

[0017] Another embodiment of the present invention is a display device having any of the above structures, in which the first auxiliary electrode contains silver and magnesium.

[0018] In the display device having the above configuration, the first auxiliary electrode more preferably has a thickness of 1 nm or more and 50 nm or less.

[0019] In addition, in the display device having each of the above configurations, it is more preferable that an insulating layer is provided, and the insulating layer is located between the first EL layer and the second EL layer. Effect of the Invention

[0020] According to one embodiment of the present invention, a display device with high display quality can be provided. A display device with low power consumption can be provided. A display device which can easily be made high definition can be provided. A display device which has both high display quality and high definition can be provided. A display device with high contrast can be provided.

[0021] According to one embodiment of the present invention, a display device having a novel structure or a method for manufacturing the display device can be provided. Also, a method for manufacturing the above-described display device with high yield can be provided. According to one embodiment of the present invention, at least one of the problems of the prior art can be at least alleviated.

[0022] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. Note that effects other than these can be extracted from the description in the specification, drawings, claims, etc. [Brief description of the drawings]

[0023] [Figure 1] 1A and 1B are diagrams showing a configuration example of a display device. [Diagram 2] Fig. 2(A) shows the absorptance of an Ag:Mg film, and Fig. 2(B) shows the simulation results of the current efficiency of a light-emitting device. [Diagram 3] 3A and 3B are diagrams showing a configuration example of a display device. [Figure 4] 4(A) and 4(B) are diagrams showing configuration examples of a display device. [Diagram 5] 5A to 5E are diagrams illustrating an example of a method for manufacturing a display device. [Figure 6] 6A to 6D are diagrams illustrating an example of a method for manufacturing a display device. [Figure 7] 7A to 7D are diagrams illustrating an example of a method for manufacturing a display device. [Figure 8] 8A to 8C are diagrams illustrating an example of a method for manufacturing a display device. [Figure 9] 9A to 9C are diagrams illustrating an example of a method for manufacturing a display device. [Figure 10] 10A to 10C are diagrams illustrating an example of a method for manufacturing a display device. [Figure 11] 11A to 11C are diagrams showing configuration examples of a light-emitting device. [Figure 12] FIG. 12 is a diagram illustrating a configuration example of a light-emitting device. [Figure 13] 13(A) and 13(B) are perspective views showing an example of a display device. [Figure 14] 14(A) and 14(B) are cross-sectional views showing an example of a display device. [Figure 15] FIG. 15 is a perspective view showing an example of a display device. [Figure 16] FIG. 16 is a cross-sectional view showing an example of a display device. [Figure 17] FIG. 17 is a cross-sectional view showing an example of a display device. [Figure 18] 18A to 18D are diagrams illustrating examples of electronic devices. [Figure 19] 19A to 19F are diagrams illustrating examples of electronic devices. [Figure 20] 20A to 20G are diagrams illustrating examples of electronic devices. [Figure 21] FIG. 21 is a graph showing the current efficiency-luminance characteristics of the light-emitting device 1A and the light-emitting device 1B. [Figure 22] FIG. 22 is a diagram showing the blue index-luminance characteristics of the light emitting device 2A and the light emitting device 2B. [Diagram 23] FIG. 23 is a diagram showing the current density-voltage characteristics of the light-emitting device 3R. [Figure 24] FIG. 24 is a graph showing the current efficiency-current density characteristics of the light-emitting device 3R. [Diagram 25] FIG. 25 is a graph showing the external quantum efficiency-current density characteristics of the light-emitting device 3R. [Figure 26]FIG. 26 shows the electroluminescence spectrum of the light-emitting device 3R. [Figure 27] FIG. 27 is a diagram showing the current density-voltage characteristics of the light-emitting device 3G. [Figure 28] FIG. 28 is a graph showing the current efficiency-current density characteristics of the light-emitting device 3G. [Figure 29] FIG. 29 is a graph showing the external quantum efficiency-current density characteristics of the light-emitting device 3G. [Diagram 30] FIG. 30 shows the electroluminescence spectrum of light-emitting device 3G. [Diagram 31] FIG. 31 is a graph showing the current density-voltage characteristics of the light-emitting device 3B. [Diagram 32] FIG. 32 is a graph showing the blue index-current density characteristics of light-emitting device 3B. [Diagram 33] FIG. 33 is a graph showing the external quantum efficiency-current density characteristics of the light-emitting device 3B. [Diagram 34] FIG. 34 shows the electroluminescence spectrum of light-emitting device 3B. [Diagram 35] FIG. 35 is a graph showing the current efficiency-luminance characteristics of the light-emitting device 4A and the light-emitting device 4B. [Diagram 36] FIG. 36 is a graph showing the current efficiency-luminance characteristics of the light-emitting device 5A and the light-emitting device 5B. [Figure 37] FIG. 37 is a diagram showing the blue index-luminance characteristics of the light-emitting device 6A and the light-emitting device 6B. [Figure 38] FIG. 38 is a diagram showing the current density-voltage characteristics of the light-emitting device 7R. [Figure 39] FIG. 39 is a graph showing the external quantum efficiency-current density characteristics of the light-emitting device 7R. [Diagram 40] FIG. 40 is a graph showing the current density-voltage characteristics of the light-emitting device 7G. [Diagram 41] FIG. 41 is a graph showing the external quantum efficiency-current density characteristics of the light-emitting device 7G. [Diagram 42] FIG. 42 is a graph showing the current density-voltage characteristics of the light-emitting device 7B. [Diagram 43] FIG. 43 is a graph showing the external quantum efficiency-current density characteristics of the light-emitting device 7B. [Diagram 44] FIG. 44 is a diagram showing the change in luminance of the light-emitting device 7R with respect to the driving time. [Diagram 45] FIG. 45 is a diagram showing the change in luminance of light-emitting device 7G with respect to the driving time. [Diagram 46] FIG. 46 is a diagram showing the change in luminance of light emitting device 7B with respect to the driving time. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, the embodiments will be described with reference to the drawings. However, it will be easily understood by those skilled in the art that the embodiments can be implemented in many different ways, and that the modes and details can be changed in various ways without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the following embodiments.

[0025] In the configuration of the invention described below, the same parts or parts having similar functions are denoted by the same reference numerals in different drawings, and the repeated explanations are omitted. In addition, when referring to similar functions, the same hatch pattern may be used and no particular reference numeral may be used.

[0026] In addition, in each figure described in this specification, the size of each component, the thickness of a layer, or an area may be exaggerated for clarity, and therefore, the drawings are not necessarily limited to the scale.

[0027] In addition, ordinal numbers such as "first" and "second" in this specification are used to avoid confusion of components and do not limit the numbers.

[0028] In addition, in this specification and the like, the terms "film" and "layer" can be interchangeable. For example, the terms "conductive layer" and "insulating layer" can be interchangeable with the terms "conductive film" and "insulating film".

[0029] In this specification, the EL layer refers to a layer that is provided between a pair of electrodes of a light-emitting device and contains at least a light-emitting substance (also referred to as a light-emitting layer), or a laminate that contains a light-emitting layer. In addition, in this specification and the like, the EL layer may be referred to as an organic compound layer.

[0030] In this specification and the like, a display panel, which is one aspect of a display device, has a function of displaying (outputting) an image or the like on a display surface. Therefore, the display panel is one aspect of an output device.

[0031] In addition, in this specification, a display panel having a connector such as an FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) attached to the substrate, or a substrate having an IC mounted thereon using a COG (Chip On Glass) method or the like, may be referred to as a display panel module, display module, or simply a display panel.

[0032] The light-emitting device of one embodiment of the present invention may include a layer containing a substance having a high hole-injection property, a substance having a high hole-transport property, a substance having a high electron-transport property, a substance having a high electron-injection property, a bipolar substance, or the like.

[0033] (Embodiment 1) In this embodiment, a structural example of a display device according to one embodiment of the present invention and an example of a manufacturing method of the display device will be described.

[0034] One embodiment of the present invention is a display device having a light-emitting device (also referred to as a light-emitting element). The display device has at least two light-emitting devices that emit light of different colors. Each of the light-emitting devices has a pair of electrodes and an EL layer between them. As the light-emitting device, an electroluminescent device such as an organic EL element or an inorganic EL element can be used. Alternatively, a light-emitting diode (LED) can be used. The light-emitting device of one embodiment of the present invention is preferably an organic EL element (organic electroluminescent device). Two or more light-emitting devices that emit different colors each have an EL layer containing a different material. For example, a full-color display device can be realized by having three types of light-emitting devices that emit red (R), green (G), or blue (B) light.

[0035] Here, when EL layers are separately formed between light-emitting devices of different colors, it is known to form them by a deposition method using a shadow mask such as a metal mask. However, in this method, due to various influences such as the accuracy of the metal mask, the positional deviation between the metal mask and the substrate, the deflection of the metal mask, and the spread of the contour of the film formed due to the scattering of vapor, the shape and position of the island-shaped organic film deviate from the design, making it difficult to achieve high definition and high aperture ratio. In addition, dust may be generated due to the material attached to the metal mask during deposition. There is a concern that such dust may cause pattern defects in the light-emitting device. In addition, there is a possibility that a short circuit may occur due to the dust. In addition, a process of cleaning the material attached to the metal mask is required. Therefore, measures have been taken to artificially increase the definition (also called pixel density) by applying a special pixel arrangement method such as a pentile arrangement.

[0036] In one embodiment of the present invention, the EL layer is processed into a fine pattern by photolithography without using a shadow mask such as a metal mask. This makes it possible to realize a display device with high definition and a large aperture ratio, which have been difficult to achieve so far. Furthermore, since the EL layer can be separately produced, a display device with extremely vivid images, high contrast, and high display quality can be realized.

[0037] For simplicity, a case where EL layers of a two-color light-emitting device are separately formed will be described here. First, a first EL film and a first sacrificial film are laminated to cover the pixel electrodes (Step A). ​​Next, a resist mask is formed on the first sacrificial film. Next, a part of the first sacrificial film and a part of the first EL film are etched using the resist mask to form a first EL layer and a first sacrificial layer on the first EL layer.

[0038] Next, a second EL film and a second sacrificial film are laminated to form the second EL layer and the second sacrificial layer on the second EL layer by etching a part of the second sacrificial film and a part of the second EL film using a resist mask. In this way, the first EL layer and the second EL layer can be separately formed. Finally, the first sacrificial layer and the second sacrificial layer are removed and a common electrode is formed, thereby separately forming a two-color light-emitting device.

[0039] Furthermore, by repeating the above process, it is possible to separately fabricate EL layers of light-emitting devices of three or more colors, thereby realizing a display device having light-emitting devices of three or four or more colors.

[0040] The display device according to one embodiment of the present invention further includes an auxiliary electrode located between the EL layer of at least one light-emitting device and the common electrode. The auxiliary electrode is light-transmitting and also functions as an optical adjustment layer for the light-emitting device. The auxiliary electrode is processed by photolithography simultaneously with the EL layer of the light-emitting device, so that the edge (contour) of the EL layer and the edge of the auxiliary electrode are roughly aligned in the direction perpendicular to the substrate.

[0041] When an auxiliary electrode is provided for each of the two-color light-emitting devices, a first EL film, a first conductive film serving as the first auxiliary electrode, and a first sacrificial film are laminated to cover the pixel electrodes. Then, a resist mask is formed on the first sacrificial film. Then, a part of the first sacrificial film, a part of the first conductive film, and a part of the first EL film are etched using the resist mask to form a first EL layer, a first auxiliary electrode on the first EL layer, and a first sacrificial layer on the first auxiliary electrode (Step A).

[0042] Following step A, a second EL film, a second conductive film serving as a second auxiliary electrode, and a second sacrificial film are laminated to form the second EL film. Then, a resist mask is used to etch a part of the second sacrificial film, a part of the second conductive film, and a part of the second EL film to form a second EL layer, a second auxiliary electrode on the second EL layer, and a second sacrificial layer on the second auxiliary electrode. In this way, the first auxiliary electrode and the second auxiliary electrode can be separately formed. Finally, the first sacrificial layer and the second sacrificial layer are removed, and a common electrode is formed, thereby separately forming a two-color light-emitting device having different auxiliary electrodes.

[0043] In the case where an auxiliary electrode is provided on one side of a two-color light-emitting device and an auxiliary electrode is not provided on the other side, a second EL film and a second sacrificial film are laminated and formed following step A. Then, a part of the second sacrificial film and a part of the second EL film are etched using a resist mask to form a second EL layer and a second sacrificial layer on the second EL layer. In this manner, the first EL layer and the second EL layer can be separately produced. Finally, the first sacrificial layer and the second sacrificial layer are removed and a common electrode is formed, so that a light-emitting device having an auxiliary electrode and a light-emitting device not having an auxiliary electrode can be separately produced.

[0044] By preparing a different auxiliary electrode for each light-emitting device, the configuration (film thickness, material, etc.) of the auxiliary electrode can be changed for each light-emitting device. This makes it easy to perform optical adjustment and optimization for each light-emitting device. In one embodiment of the present invention, the auxiliary electrode can also be called an optical adjustment layer, since the optical adjustment of the light-emitting device can be performed by controlling the auxiliary electrode.

[0045] When EL layers of different colors are adjacent to each other, it is difficult to make the interval between adjacent EL layers less than 10 μm, for example, by using a metal mask. However, by processing using a photolithography method, the interval can be narrowed to 3 μm or less, 2 μm or less, or 1 μm or less. For example, by using an exposure device for LSI, the interval can be narrowed to 500 nm or less, 200 nm or less, 100 nm or less, or even 50 nm or less. This allows the area of ​​the non-light-emitting region that may exist between two light-emitting devices to be significantly reduced, and the aperture ratio can be made close to 100%. For example, the aperture ratio can be 50% or more, 60% or more, 70% or more, 80% or more, or even 90% or more, and can be less than 100%.

[0046] Furthermore, when adjacent light-emitting devices each have an auxiliary electrode, the distance between the auxiliary electrodes can be narrowed to 3 μm or less, 2 μm or less, or 1 μm or less by processing using a photolithography method. For example, by using an exposure device for LSIs, the distance can be narrowed to 500 nm or less, 200 nm or less, 100 nm or less, or even 50 nm or less.

[0047] Furthermore, the pattern of the EL layer itself can be made much smaller than when a metal mask is used. For example, when a metal mask is used to separately fabricate the EL layer, the thickness varies between the center and the edge of the pattern, so the effective area that can be used as the light-emitting region is small compared to the area of ​​the entire pattern. On the other hand, by processing using a photolithography method, a film formed to a uniform thickness can be processed, so that the thickness can be made uniform within the pattern, and even if the pattern is fine, almost the entire area can be used as the light-emitting region. Therefore, the above-mentioned manufacturing method can achieve both high definition and high aperture ratio.

[0048] In this way, according to the above-mentioned manufacturing method, it is possible to realize a display device that integrates fine light-emitting devices, and thus it is possible to realize a display device with a so-called stripe arrangement and a resolution of 500 ppi or more, 1000 ppi or more, 2000 ppi or more, or even 3000 ppi or more, or even 5000 ppi or more.

[0049] A specific example of a configuration and a manufacturing method of a display device according to one embodiment of the present invention will be described below with reference to the drawings.

[0050] As shown in FIGS. 1A and 1B, a plurality of light-emitting devices 130 are formed on an insulating layer 175 to constitute a display device 100.

[0051] The display device 100 includes a pixel section 177 in which a plurality of pixels 178 are arranged in a matrix. The pixel 178 includes a sub-pixel 110R, a sub-pixel 110G, and a sub-pixel 110B.

[0052] Hereinafter, when describing matters common to the subpixels 110R, 110G, and 110B, they may simply be referred to as subpixel 110. When describing matters common to other components distinguished by alphabets, they may also be described using symbols without the alphabets.

[0053] The subpixel 110R emits red light, the subpixel 110G emits green light, and the subpixel 110B emits blue light. This allows an image to be displayed in the pixel section 177. In the present embodiment, subpixels of three colors, red (R), green (G), and blue (B), are described as an example, but combinations of subpixels of other colors may be used. The number of subpixels is not limited to three, and may be four or more. Examples of the four subpixels include four subpixels of R, G, B, and white (W), four subpixels of R, G, B, and yellow (Y), and four subpixels of R, G, B, and infrared (IR). A sensor may be further provided in the pixel 178, and the sensor is preferably an organic photodiode sensor using an organic compound. In the organic photodiode sensor using an organic compound, a part of a layer that transports carriers can be formed from a material common to the light-emitting device.

[0054] In this specification and the like, the row direction may be referred to as the X direction, and the column direction may be referred to as the Y direction. The X direction and the Y direction intersect, for example, perpendicularly.

[0055] 1A shows an example in which subpixels of different colors are arranged side by side in the X direction, and subpixels of the same color are arranged side by side in the Y direction. Note that subpixels of different colors may be arranged side by side in the Y direction, and subpixels of the same color may be arranged side by side in the X direction.

[0056] A connection section 140 is provided outside the pixel section 177, and a region 141 may be further provided. The region 141 is provided between the pixel section 177 and the connection section 140. The EL layer 103 is provided in the region 141. The connection section 140 is provided with a conductive layer 151C.

[0057] 1A shows an example in which the region 141 and the connection portion 140 are located on the right side of the pixel portion 177, but the positions of the region 141 and the connection portion 140 are not particularly limited. The region 141 and the connection portion 140 may be singular or plural.

[0058] Fig. 1(B) is an example of a cross-sectional view between dashed line A1-A2 in Fig. 1(A). As shown in Fig. 1(B), the display device 100 has an insulating layer 171, a conductive layer 172 on the insulating layer 171, an insulating layer 173 on the insulating layer 171 and on the conductive layer 172, an insulating layer 174 on the insulating layer 173, and an insulating layer 175 on the insulating layer 174. The insulating layer 171 is provided on a substrate (not shown). An opening reaching the conductive layer 172 is provided in the insulating layer 175, the insulating layer 174, and the insulating layer 173, and a plug 176 is provided to fill the opening.

[0059] In the pixel section 177, the light emitting device 130R, the light emitting device 130G, and the light emitting device 130B are provided on the insulating layer 175 and the plug 176. In the following, when the matters common to the light emitting device 130R, the light emitting device 130G, and the light emitting device 130B are described, they may be simply referred to as the light emitting device 130. On the second electrode 102 of the light emitting device 130, a protective layer 131 is provided so as to cover the light emitting device 130. The protective layer 131 can be formed by a method such as a vacuum deposition method, a sputtering method, a chemical vapor deposition (CVD) method, or an atomic layer deposition (ALD) method. When the protective layer 131 is an inorganic insulating film formed by a plasma-enhanced atomic layer deposition (PEALD) method, a film with high barrier properties can be formed at a low temperature. This can reduce damage to the EL layer of each light emitting device, and it becomes easy to obtain a display device with high display quality. In addition, it is possible to effectively suppress the intrusion of substances that accelerate the deterioration of the EL layer and the second electrode 102, such as water, oxygen, and trace components in the air, and a display device with high display quality can be obtained. Since the inorganic insulating film formed by the PEALD method has high barrier properties, it is possible to form the protective layer 131 thin, and a display device with high display quality can be obtained. Note that the protective layer 131 may have a laminated structure of two or more layers.

[0060] The substrate 120 is attached onto the protective layer 131 by a resin layer 122. In addition, between adjacent light emitting devices 130, a second insulating layer 125a and a first insulating layer 127 on the second insulating layer 125a are preferably provided.

[0061] The second insulating layer 125a is provided so as to contact side surfaces of the EL layers of the light-emitting device 130. The second insulating layer 125a is preferably provided so as to contact side surfaces of the pixel electrodes (first electrode 101R, first electrode 101G, first electrode 101B) of the light-emitting device 130. The second insulating layer 125a is preferably provided so as to contact side surfaces and a bottom surface of the first insulating layer 127.

[0062] With the above-mentioned configuration, the first insulating layer 127 can be separated from the EL layer of the light-emitting device 130 by the second insulating layer 125a.

[0063] The second insulating layer 125a functions as a protective insulating layer for the EL layer of the light-emitting device 130. The second insulating layer 125a preferably has a barrier property against at least one of oxygen and moisture. By isolating the first insulating layer 127 and the EL layer with such a second insulating layer 125a, it is possible to suppress the intrusion of oxygen, moisture, or their constituent elements into the inside from the side surface of the EL layer, and it is possible to provide a highly reliable display device.

[0064] The thickness of the second insulating layer 125a in the region in contact with the side surface of the EL layer of the light-emitting device 130 is preferably 5 nm to 50 nm, more preferably 5 nm to 30 nm, even more preferably 5 nm to 20 nm, and more preferably 5 nm to 10 nm. By setting the thickness of the second insulating layer 125a in the above-mentioned range, a display device having a high aperture ratio and high reliability can be obtained.

[0065] The second insulating layer 125a can be an insulating layer containing an inorganic material. As the second insulating layer 125a, silicon oxide, silicon oxynitride, silicon nitride, silicon nitride oxide, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, or the like can be used as a single layer or a stacked layer. In particular, a silicon-based insulating film such as silicon oxide, silicon oxynitride, silicon nitride, or silicon nitride oxide is preferable.

[0066] In this specification, an oxynitride refers to a material having a higher oxygen content than nitrogen, and a nitride oxide refers to a material having a higher nitrogen content than oxygen. For example, silicon oxynitride refers to a material having a higher oxygen content than nitrogen, and silicon nitride oxide refers to a material having a higher nitrogen content than oxygen.

[0067] The first insulating layer 127 provided on the second insulating layer 125a fills the gap formed between adjacent light emitting devices, thereby reducing the step on the surface on which the second electrode 102 is formed, and improving the coverage, thereby suppressing the occurrence of defects such as step disconnection. An insulating layer having an organic material can be suitably used as the first insulating layer 127. For example, acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimideamide resin, siloxane resin, benzocyclobutene resin, phenolic resin, and precursors of these resins can be applied as the first insulating layer 127. In addition, a photosensitive resin can be used as the first insulating layer 127. The photosensitive resin can be a positive type material or a negative type material.

[0068] In FIG. 1B, the light emitting device 130 includes a light emitting device 130R, a light emitting device 130G, and a light emitting device 130B. The light emitting device 130R, the light emitting device 130G, and the light emitting device 130B are light emitting devices that emit light of different colors. The light emitted by the light emitting device 130R has a longer wavelength than the light emitted by the light emitting device 130G. The light emitted by the light emitting device 130G has a longer wavelength than the light emitted by the light emitting device 130B. For example, the light emitting device 130R can emit red light (R), the light emitting device 130G can emit green light (G), and the light emitting device 130B can emit blue light (B). The light emitting device 130R, the light emitting device 130G, or the light emitting device 130B may emit other visible light or infrared light.

[0069] In this specification, the emission color of a light emitting device can be determined by the peak wavelength of the electroluminescence spectrum of the light emitting device. For example, when the difference between the maximum peak wavelength in the visible light region of the electroluminescence spectrum of the first light emitting device and the maximum peak wavelength in the visible light region of the electroluminescence spectrum of the second light emitting device is 50 nm or more, the emission colors of the first light emitting device and the second light emitting device are different.

[0070] In this specification, the blue wavelength region is a wavelength region of 400 nm or more and less than 490 nm, and blue emission is emission having at least one emission spectrum peak in this region. The green wavelength region is a wavelength region of 490 nm or more and less than 580 nm, and green emission is emission having at least one emission spectrum peak in this region. The red wavelength region is a wavelength region of 580 nm or more and less than 780 nm, and red emission is emission having at least one emission spectrum peak in this region.

[0071] The display device of one embodiment of the present invention can be a top emission type that emits light in a direction opposite to the substrate on which the light-emitting device is formed. Note that one embodiment of the present invention is not limited thereto, and the display device may be a dual emission type that extracts light emitted by the light-emitting device both above and below the substrate on which the light-emitting device is formed.

[0072] The light-emitting device 130R has a first electrode 101R (pixel electrode) consisting of a conductive layer 151R and a conductive layer 152R, an EL layer 104R on the first electrode 101R, an auxiliary electrode 106R on the EL layer 104R, and a second electrode 102 (common electrode) on the auxiliary electrode 106R. In other words, in the light-emitting device 130R, the EL layer 104R is located between the first electrode 101R and the second electrode 102, and the auxiliary electrode 106R is located between the EL layer 104R and the second electrode 102. The light-emitting device 130R also has a protective layer 158R on the auxiliary electrode 106R in a region where the auxiliary electrode 106R and the second electrode 102 are not connected.

[0073] The light-emitting device 130G has a first electrode 101G (pixel electrode) consisting of a conductive layer 151G and a conductive layer 152G, an EL layer 104G on the first electrode 101G, an auxiliary electrode 106G on the EL layer 104G, and a second electrode 102 (common electrode) on the auxiliary electrode 106G. In other words, in the light-emitting device 130G, the EL layer 104G is located between the first electrode 101G and the second electrode 102, and the auxiliary electrode 106G is located between the EL layer 104G and the second electrode 102. The light-emitting device 130G also has a protective layer 158G on the auxiliary electrode 106G in a region where the auxiliary electrode 106G and the second electrode 102 are not connected.

[0074] The light-emitting device 130B has a first electrode 101B (pixel electrode) consisting of a conductive layer 151B and a conductive layer 152B, an EL layer 104B on the first electrode 101B, an auxiliary electrode 106B on the EL layer 104B, and a second electrode 102 (common electrode) on the auxiliary electrode 106B. In other words, in the light-emitting device 130B, the EL layer 104B is located between the first electrode 101B and the second electrode 102, and the auxiliary electrode 106B is located between the EL layer 104B and the second electrode 102. The light-emitting device 130B also has a protective layer 158B on the auxiliary electrode 106B in a region where the auxiliary electrode 106B and the second electrode 102 are not connected.

[0075] The EL layer 104R, EL layer 104G, and EL layer 104B are formed by forming an EL film and processing the EL film using a photolithography method, and therefore, each of them is independent in an island shape for each light-emitting color. It is preferable that the EL layer 104R, EL layer 104G, and EL layer 104B do not overlap each other. By providing an EL layer in an island shape for each light-emitting device 130, it is possible to suppress leakage current between adjacent light-emitting devices 130 even in a high-definition display device. This makes it possible to prevent crosstalk and realize a display device with extremely high contrast. In particular, it is possible to realize a display device with high current efficiency at low luminance. In the following, when matters common to the EL layer 104R, EL layer 104G, and EL layer 104B are explained, they may be simply referred to as EL layer 104.

[0076] One of the pixel electrode (first electrode) and the common electrode (second electrode) of the light-emitting device functions as an anode, and the other functions as a cathode. In this embodiment, unless otherwise specified, the pixel electrode functions as an anode, and the common electrode functions as a cathode. In addition, the auxiliary electrode of the light-emitting device is located between the EL layer and the common electrode, and when the common electrode functions as a cathode, the auxiliary electrode also functions as a cathode, and when the common electrode functions as an anode, the auxiliary electrode also functions as an anode.

[0077] The auxiliary electrodes 106R, 106G, and 106B are formed by forming a conductive film and processing the conductive film using a photolithography method, similarly to the EL layers 104R, 104G, and 104B, and are thus independent in an island shape for each or each light-emitting color. By providing the auxiliary electrodes in an island shape for each light-emitting device 130, the configuration (film thickness, material, etc.) of the auxiliary electrodes can be changed for each light-emitting device 130, and therefore optical adjustment can be performed for each light-emitting device 130. The auxiliary electrodes 106R, 106G, and 106B can also be said to function as optical adjustment layers. In the following, when matters common to the auxiliary electrodes 106R, 106G, and 106B are described, they may be simply referred to as the auxiliary electrodes 106.

[0078] It is preferable to use a conductive film having light-transmitting properties (such as a transparent conductive film or a semi-transmissive / semi-reflective conductive film) for the second electrode 102 (common electrode), the auxiliary electrode 106R, the auxiliary electrode 106G, and the auxiliary electrode 106B. In this specification and the like, visible light refers to light having a wavelength of 400 nm or more and less than 780 nm. In this specification and the like, having light-transmitting properties refers to a light having a transmittance of 5% or more for at least a part of the wavelengths in the visible light range. In this specification and the like, a conductive film refers to a conductive film having a resistivity of 10×10 8 This refers to a film with a resistivity of Ωcm or less. Note that resistivity is calculated by dividing the resistance value of a sample by its length and multiplying it by its cross-sectional area. It is different from sheet resistance, which is calculated by dividing the resistance value of a sample by its length and multiplying it by its width.

[0079] A conductive film having a transmittance of 40% or more for light of at least a part of wavelengths in the visible light region is considered to be a transparent conductive film. The transmittance is preferably 50% or more, more preferably 60% or more, more preferably 70% or more, more preferably 80% or more, and more preferably 90% or more. Specific examples of transparent conductive films include indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, indium tin oxide (hereinafter referred to as ITO), indium zinc oxide, and indium tin oxide with added silicon oxide. In addition, a film of an organic material having high conductivity, or a mixed film of an organic material and an inorganic material may be used as the transparent conductive film. Specific examples of organic materials having high conductivity include materials having electron transport properties and materials having hole transport properties. Specific examples of mixed films of organic materials and inorganic materials include a mixed film of a material having electron transport properties and Li, and a mixed film of a material having hole transport properties and MoO3.

[0080] A conductive film having a reflectance of 10% or more and 95% or less for light of at least a part of the wavelengths in the visible light region is defined as a semi-transmissive / semi-reflective conductive film. The lower limit of the reflectance is preferably 20% or more, more preferably 30% or more, and more preferably 40% or more. The upper limit of the reflectance is preferably 90% or less, more preferably 80% or less, and more preferably 70% or less. Furthermore, the transmittance of light of at least a part of the wavelengths in the visible light region of the semi-transmissive / semi-reflective conductive film is preferably 10% or more, more preferably 20% or more, and more preferably 30% or more. Specific examples of semi-transmissive / semi-reflective conductive films include films formed by co-evaporation of Ag:Mg (silver-magnesium alloy), Mg:In ​​(magnesium-indium alloy), etc., or films formed by co-evaporation of an element belonging to Group 1 or Group 2 of the periodic table and aluminum.

[0081] In order to stably form an electrode and to function sufficiently as an optical adjustment layer, the lower limit of the thickness of the auxiliary electrode 106 is preferably 1 nm or more, more preferably 5 nm or more, and more preferably 10 nm or more. When a micro-optical resonator (microcavity) structure is applied to each light-emitting device, the thickness of the auxiliary electrode can be increased to narrow the electroluminescence spectrum and improve color purity.

[0082] On the other hand, if the thickness of the auxiliary electrode 106 becomes too large, the absorption rate of visible light may increase, and the light extraction efficiency of the light-emitting device may decrease. Therefore, in order to prevent a decrease in the light extraction efficiency, when a transparent conductive film is used for the auxiliary electrode 106, the upper limit of the film thickness is preferably 200 nm or less, preferably 100 nm or less, preferably 50 nm or less, and more preferably 30 nm or less. When a semi-transmissive / semi-reflective conductive film is used for the auxiliary electrode 106, the film thickness is preferably 50 nm or less, preferably 40 nm or less, preferably 30 nm or less, and more preferably 20 nm or less. When a semi-transmissive / semi-reflective conductive film is used for both the second electrode 102 and the auxiliary electrode 106, the film thickness of the laminated structure of the second electrode 102 and the auxiliary electrode 106 is preferably 50 nm or less, preferably 40 nm or less, preferably 30 nm or less, and more preferably 20 nm or less. By making the auxiliary electrode 106 have such a thickness, it is possible to suppress an increase in the absorption rate of visible light and improve the light extraction efficiency of the light emitting device while ensuring the function as an optical adjustment layer.

[0083] The visible light absorptance of a transparent conductive film may vary depending on the wavelength of light. Figure 2(A) shows the light absorptance of Ag:Mg films (thickness 15nm and 25nm) formed by co-evaporating Ag and Mg at a volume ratio of 1:0.1 on a quartz substrate. A UV-visible spectrophotometer (U-4100 manufactured by Hitachi, Ltd.) was used for the measurement. The absorptance shown in Figure 2(A) shows the ratio of the value obtained by subtracting the transmitted light intensity and the reflected light intensity from the irradiated light intensity to the irradiated light intensity. As shown in Figure 2(A), it was found that the Ag:Mg film with a thickness of 25nm has a higher absorptance than the Ag:Mg film with a thickness of 15nm. Also, Figure 2(A) shows that the Ag:Mg film has a higher absorptance of short-wavelength light. When materials having different absorptances depending on the wavelength of light are used for auxiliary electrodes 106R, 106G, and 106B, it is preferable to make the thicknesses of auxiliary electrodes 106R, 106G, and 106B different from one another to achieve optimal thicknesses for each light-emitting device.

[0084] In the case where a material having a higher absorptivity for short-wavelength light, such as an Ag:Mg film, is used for auxiliary electrodes 106R, 106G, and 106B, and where light-emitting device 130R emits red light, light-emitting device 130G emits green light, and light-emitting device 130B emits blue light, it is preferable to configure auxiliary electrode 106R so that its thickness is greater than that of auxiliary electrode 106G, and auxiliary electrode 106G so that its thickness is greater than that of auxiliary electrode 106B, as shown in Fig. 1(B). In this way, the light extraction efficiency of each light-emitting device can be improved.

[0085] 2(A), the Ag:Mg film had an absorptance of 6.49% for red light (wavelength 700 nm) when the film thickness was 15 nm and 9.56% for the film thickness of 25 nm, an absorptance of 6.97% for green light (wavelength 546 nm) when the film thickness was 15 nm and 13.14% for the film thickness of 25 nm, and an absorptance of 8.70% for blue light (wavelength 436 nm) when the film thickness was 15 nm and 21.47% for the film thickness of 25 nm. From this, it was found that the difference in absorptance between the film thickness of 15 nm and the film thickness of 25 nm becomes larger as the wavelength becomes shorter. Therefore, it was found that the effect of thinning the auxiliary electrode 106 becomes even greater as the wavelength becomes shorter.

[0086] When a material with a higher absorptivity for short-wavelength light, such as an Ag:Mg film, is used for the auxiliary electrodes 106, it is preferable to control the film thickness of each auxiliary electrode so that the absorptivity of the light of the color emitted by the light-emitting device 130 in the auxiliary electrodes 106 is 30% or less, preferably 10% or less, and more preferably 5% or less.

[0087] Furthermore, when a material having a high absorptivity for short-wavelength light, such as an Ag:Mg film, is used for both the second electrode 102 and the auxiliary electrode 106, it is preferable to control the film thickness of each auxiliary electrode so that the laminated structure of the second electrode 102 and the auxiliary electrode 106 has an absorptivity for light of the emitted color of the light-emitting device of 30% or less, preferably 10% or less, and more preferably 5% or less.

[0088] Therefore, when the Ag:Mg film is used for the auxiliary electrode 106 or both the second electrode 102 and the auxiliary electrode 106, the thickness of the Ag:Mg film in the red light emitting device is preferably 50 nm or less, 35 nm or less, or 20 nm or less, the thickness of the Ag:Mg film in the green light emitting device is preferably 45 nm or less, 30 nm or less, or 15 nm or less, and the thickness of the Ag:Mg film in the blue light emitting device is preferably 35 nm or less, 25 nm or less, or 15 nm or less. However, when the Ag:Mg film is used for both the second electrode 102 and the auxiliary electrode 106, the thickness of the Ag:Mg film refers to the thickness of the laminated structure of the second electrode 102 and the auxiliary electrode 106. With such a configuration, the light extraction efficiency of each light emitting device can be improved.

[0089] For a specific explanation, Fig. 2(B) shows the results of simulating the change in current efficiency by changing the cathode film thickness (corresponding to the total film thickness of the second electrode 102 and the auxiliary electrode 106 in one embodiment of the present invention) in each of the red, green, and blue light-emitting devices, respectively, and shows the relative ratio when the current efficiency for a cathode of 25 nm is set to 1. The simulation was performed using an organic EL / solar cell simulator (setfos, manufactured by Fluxim AG) on the assumption that Ag:Mg is used for the cathode. Note that the efficiency of light emitted in a direction perpendicular to the light-emitting surface will be discussed below.

[0090] As shown in Figure 2(B), in the red-light-emitting device, the current efficiency was higher when the cathode film thickness was 25 nm than when it was 15 nm, in the green-light-emitting device, the current efficiency was higher when the cathode film thickness was 15 nm than when it was 25 nm, and in the blue-light-emitting device, the current efficiency was significantly higher when the cathode film thickness was 15 nm than when it was 25 nm. Since the Ag:Mg film has a low absorptance for red light, it can be said that the current efficiency was higher in the red-light-emitting device as the cathode film thickness was thicker, because the microcavity structure improved the directivity of light in the direction perpendicular to the light-emitting surface. On the other hand, since the Ag:Mg film has a high absorptance for blue light, the current efficiency was higher in the blue-light-emitting device as the cathode film thickness was thinner, because the light absorption by the cathode was suppressed.

[0091] In this way, by changing the cathode film thickness (or the film thickness of the auxiliary electrode) of the light-emitting device of each color, the efficiency of each light-emitting device can be improved. Therefore, in the display device of one embodiment of the present invention, the efficiency of each light-emitting device can be improved by forming a separate auxiliary electrode for each light-emitting device. Therefore, a display device with low power consumption can be provided.

[0092] 3 and 4 show cross-sectional views of modifications of the display device shown in FIG. 1(B).

[0093] The display device according to one embodiment of the present invention shown in FIG. 3A is different from the display device shown in FIG. 1B in that the light-emitting device 130B does not have the auxiliary electrode 106B. When the auxiliary electrode 106B is not provided, the second electrode 102 (common electrode) is located on the EL layer 104B in the light-emitting device 130B. In other words, in the light-emitting device 130B without the auxiliary electrode 106B, the EL layer 104B is located between the first electrode 101B and the second electrode 102 and is in contact with the second electrode 102. In this manner, the light extraction efficiency of each light-emitting device can be increased by providing the auxiliary electrode 106 in some light-emitting devices (here, the light-emitting device 130R and the light-emitting device 130G) and not providing the auxiliary electrode 106 in the other light-emitting devices (here, the light-emitting device 130B). Furthermore, when the auxiliary electrode 106B is not provided in this manner, the manufacturing process of the display device can be simplified and the manufacturing cost can be reduced.

[0094] Furthermore, when an Ag:Mg film is used for the second electrode 102 (common electrode), the auxiliary electrode 106R, and the auxiliary electrode 106G, the upper limit of the film thickness of the second electrode 102 (common electrode) is preferably 35 nm or less, 25 nm or less, or 15 nm or less, the upper limit of the film thickness of the auxiliary electrode 106R in the red light-emitting device 130R is preferably 15 nm or less, 10 nm or less, or 5 nm or less, and the upper limit of the film thickness of the auxiliary electrode 106G in the green light-emitting device 130G is preferably 10 nm or less, 5 nm or less, or 1 nm or less.

[0095] In each of the light-emitting devices 130 shown in FIG. 1(B) and FIG. 3(A), the uppermost layer of the EL layer 104 is an electron injection layer or a charge generation layer, which facilitates electron injection from the second electrode 102 (common electrode) to the EL layer 104, and can reduce the driving voltage of each of the light-emitting devices 130. Representative materials used for the electron injection layer or charge generation layer include alkali metals such as lithium (Li) having a small work function, compounds of the alkali metals, alkaline earth metals, and compounds of the alkaline earth metals. However, in the light-emitting device 130B not provided with the auxiliary electrode 106B, if an alkali metal or a compound of the alkali metal is used for the uppermost layer of the EL layer 104B, the film quality of the EL layer 104B may be deteriorated due to the influence of oxygen or water in the air, chemical solutions, etc., when the EL layer 104B is formed by photolithography or the sacrificial layer is peeled off, which may cause an increase in the driving voltage or a decrease in the current efficiency of the light-emitting device 130B.

[0096] 3A, it is more preferable to use an electron injection layer that does not contain an alkali metal or a compound of the alkali metal as the uppermost layer of the EL layer 104B. The structure of the electron injection layer that does not contain an alkali metal or a compound of the alkali metal will be described later in the following embodiment.

[0097] Note that although FIG. 3A shows a structure in which the light-emitting device 130B is not provided with an auxiliary electrode, one embodiment of the present invention is not limited to this, and the light-emitting device 130G may be provided with no auxiliary electrode.

[0098] Fig. 3B shows a modified cross-sectional view of the display device shown in Fig. 3A. The display device of one embodiment of the present invention shown in Fig. 3B differs from the display device shown in Fig. 3A in that a common layer 107 is included.

[0099] 3(B), the light-emitting device 130R has a first electrode 101R (pixel electrode) consisting of a conductive layer 151R and a conductive layer 152R, an EL layer 104R on the first electrode 101R, an auxiliary electrode 106R on the EL layer 104R, a common layer 107 on the auxiliary electrode 106R, and a second electrode 102 (common electrode) on the common layer 107. In other words, in the light-emitting device 130R, the second electrode 102 is located on the common layer 107, the EL layer 104R is located between the first electrode 101R and the common layer 107, and the auxiliary electrode 106R is located between the EL layer 104R and the common layer 107.

[0100] 3(B), the light-emitting device 130G has a first electrode 101G (pixel electrode) composed of a conductive layer 151G and a conductive layer 152G, an EL layer 104G on the first electrode 101G, an auxiliary electrode 106G on the EL layer 104G, a common layer 107 on the auxiliary electrode 106G, and a second electrode 102 (common electrode) on the common layer 107. In other words, in the light-emitting device 130G, the second electrode 102 is located on the common layer 107, the EL layer 104G is located between the first electrode 101G and the common layer 107, and the auxiliary electrode 106G is located between the EL layer 104G and the common layer 107.

[0101] 3(B), the light-emitting device 130B has a first electrode 101B (pixel electrode) composed of a conductive layer 151B and a conductive layer 152B, an EL layer 104B on the first electrode 101B, a common layer 107 on the EL layer 104B, and a second electrode 102 (common electrode) on the common layer 107. In other words, in the light-emitting device 130B, the second electrode 102 is located on the common layer 107, the EL layer 104B is located between the first electrode 101B and the common layer 107, and the EL layer 104B is in contact with the common layer 107.

[0102] In the following, when describing matters common to conductive layer 151R, conductive layer 151G, and conductive layer 151B, they may be simply referred to as conductive layer 151. In the following, when describing matters common to conductive layer 152R, conductive layer 152G, and conductive layer 152B, they may be simply referred to as conductive layer 152.

[0103] In addition, in FIG. 3(B), the common layer 107 is preferably an electron injection layer. The common layer 107 is a layer formed after processing each EL layer using a photolithography method and removing a sacrificial layer in the manufacturing process. Therefore, it is less susceptible to oxygen or water in the air, chemical solutions, etc., and the range of material selection is widened. By using the common layer 107 as an electron injection layer, even if the top layer of the EL layer 104B is not an electron injection layer, electrons can be easily injected from the second electrode 102 to the EL layer 104B through the common layer 107, and the driving voltage of the light-emitting device 130B can be reduced.

[0104] In addition, since the common layer 107 is located between the auxiliary electrode 106R and the second electrode 102 in the light-emitting device 130R, and between the auxiliary electrode 106B and the second electrode 102 in the light-emitting device 130B, it is preferable that the common layer 107 is configured not to prevent electrical conduction between the auxiliary electrode 106 and the second electrode 102. For example, it is preferable to set the thickness of the common layer 107 to 10 nm or less, more preferably 5 nm or less, since this does not prevent electrical conduction between the auxiliary electrode 106 and the second electrode 102. Alternatively, it is preferable to use a highly conductive material for the common layer 107.

[0105] Furthermore, the display device of one embodiment of the present invention does not necessarily have to include the first insulating layer 127. The display device illustrated in Figure 4A differs from the display device illustrated in Figure 1B in that the first insulating layer 127 is not provided. By not providing the first insulating layer 127, manufacturing costs can be reduced.

[0106] 1, 3, and 4A show an example in which the ends of the EL layer 104 and the auxiliary electrode 106 are located inside the ends of the conductive layers 151 and 152 that are the first electrodes, but one embodiment of the present invention is not limited thereto, and the ends of the EL layer 104 and the auxiliary electrode 106 may be located outside the ends of the conductive layers 151 and 152. Fig. 4B shows a display device in which the ends of the EL layer 104R and the auxiliary electrode 106R are located outside the ends of the conductive layers 151R and 152R, the ends of the EL layer 104G and the auxiliary electrode 106G are located outside the ends of the conductive layers 151G and 152G, and the ends of the EL layer 104B and the auxiliary electrode 106B are located outside the ends of the conductive layers 151B and 152B.

[0107] 4B shows an example in which a third insulating layer 125b is provided over the first insulating layer 127. The third insulating layer 125b preferably has a structure similar to that of the second insulating layer 125a. By providing the third insulating layer 125b over the first insulating layer 127, the first insulating layer 127 and the second electrode 102 are separated from each other, and therefore, at least one of oxygen and moisture can be prevented from reaching the second electrode 102, and the reliability of the display device can be improved.

[0108] In the display device of one embodiment of the present invention, the first electrodes (101R, 101G, 101B) (pixel electrodes) of the light-emitting devices preferably have a stacked structure. For example, in the example shown in FIG. 1B, the first electrode 101R of the light-emitting device 130R has a stacked structure of a conductive layer 151R provided on the insulating layer 171 side and a conductive layer 152R provided on the EL layer side. The first electrode 101G of the light-emitting device 130G has a stacked structure of a conductive layer 151G provided on the insulating layer 171 side and a conductive layer 152G provided on the EL layer side. The first electrode 101B of the light-emitting device 130B has a stacked structure of a conductive layer 151B provided on the insulating layer 171 side and a conductive layer 152B provided on the EL layer side.

[0109] For example, a metal material can be used as the conductive layer 151. Specifically, metals such as aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd), and alloys containing appropriate combinations of these metals can also be used.

[0110] The conductive layer 152 can be made of an oxide containing one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon. For example, it is preferable to use a conductive oxide containing one or more of indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide containing gallium, titanium oxide, indium zinc oxide containing gallium, indium zinc oxide containing aluminum, indium tin oxide containing silicon, and indium zinc oxide containing silicon. In particular, indium tin oxide containing silicon has a large work function, for example, a work function of 4.0 eV or more, and therefore can be suitably used for the conductive layer 152.

[0111] The conductive layer 151 may have a stacked structure of multiple layers having different materials, and the conductive layer 152 may have a stacked structure of multiple layers having different materials. In this case, the conductive layer 151 may have a layer using a material that can be used for the conductive layer 152, such as a conductive oxide, or the conductive layer 152 may have a layer using a material that can be used for the conductive layer 151, such as a metal material. For example, when the conductive layer 151 has a stacked structure of two or more layers, a layer in contact with the conductive layer 152 can be a layer using a material that can be used for the conductive layer 152.

[0112] Note that an end of the conductive layer 151 may have a tapered shape. Specifically, the end of the conductive layer 151 preferably has a tapered shape with a taper angle of less than 90°. In this case, the conductive layer 152 provided along the side surface of the conductive layer 151 also has a tapered shape. By making the side surface of the conductive layer 152 tapered, the coverage of the EL layer 104 provided along the side surface of the conductive layer 152 can be improved. Note that the end of the conductive layer 151 may not have a taper and may be approximately perpendicular to the substrate surface. In this case, the distance between adjacent EL layers can be narrowed, so that a display device with a good aperture ratio can be provided.

[0113] The structure of this embodiment mode can be used in appropriate combination with other structures.

[0114] (Embodiment 2) In this embodiment, an example of a manufacturing method of a display device of one embodiment of the present invention will be described with reference to Figures 5 to 10. In Figures 5 to 10, the example of the manufacturing method will be described with reference to cross-sectional views corresponding to the dashed dotted line A1-A2 and the dashed dotted line B1-B2 in Figure 1A.

[0115] Thin films (insulating films, semiconductor films, conductive films, and the like) constituting a display device can be formed by sputtering, CVD, vacuum deposition, pulsed laser deposition (PLD), ALD, or the like.

[0116] Furthermore, the thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device can be formed by wet film formation methods such as spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, or knife coating.

[0117] Furthermore, when processing the thin films that constitute the display device, they can be processed using, for example, a photolithography method.

[0118] In the photolithography method, the light used for exposure may be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these. In addition, ultraviolet light, KrF laser light, ArF laser light, etc. may also be used. Exposure may also be performed by immersion exposure technology. Extreme ultraviolet (EUV) light or X-rays may also be used as the light used for exposure. An electron beam may also be used instead of the light used for exposure.

[0119] The thin film can be etched by dry etching, wet etching, sandblasting, or the like.

[0120] 5(A), an insulating layer 171 is formed on a substrate (not shown). Then, a conductive layer 172 and a conductive layer 179 are formed on the insulating layer 171, and an insulating layer 173 is formed on the insulating layer 171 so as to cover the conductive layer 172 and the conductive layer 179. Then, an insulating layer 174 is formed on the insulating layer 173, and an insulating layer 175 is formed on the insulating layer 174.

[0121] The substrate may be a substrate having heat resistance at least sufficient to withstand subsequent heat treatment, such as a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, an organic resin substrate, a single crystal semiconductor substrate made of silicon or silicon carbide, a polycrystalline semiconductor substrate, a compound semiconductor substrate made of silicon germanium, or an SOI substrate.

[0122] 5A, an opening reaching the conductive layer 172 is formed in the insulating layer 175, the insulating layer 174, and the insulating layer 173. Then, a plug 176 is formed to fill the opening.

[0123] 5A, a conductive film 151f, which will later become the conductive layers 151R, 151G, 151B, and 151C, is formed on the plugs 176 and the insulating layer 175. The conductive film 151f can be made of, for example, a metal material.

[0124] 5A, a resist mask 191 is formed over the conductive film 151f. The resist mask 191 can be formed by applying a photosensitive material (photoresist) and then performing exposure and development.

[0125] 5B, for example, the conductive film 151f is removed from a region that does not overlap with the resist mask 191. In this way, the conductive layer 151 is formed.

[0126] 5(C), the resist mask 191 is removed. The resist mask 191 can be removed by ashing using oxygen plasma, for example.

[0127] Next, as shown in FIG. 5(D), insulating film 156f, which will later become insulating layer 156R, insulating layer 156G, insulating layer 156B, and insulating layer 156C, is formed on conductive layer 151R, conductive layer 151G, conductive layer 151B, conductive layer 151C, and insulating layer 175.

[0128] The insulating film 156f can be an inorganic insulating film such as an insulating oxide film, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film, for example, a silicon oxynitride film.

[0129] Subsequently, as shown in FIG. 5(E), the insulating film 156f is processed to form an insulating layer 156R, an insulating layer 156G, an insulating layer 156B, and an insulating layer 156C.

[0130] Next, as shown in FIG. 6(A), a conductive film 152f is formed on the conductive layer 151R, the conductive layer 151G, the conductive layer 151B, the conductive layer 151C, the insulating layer 156R, the insulating layer 156G, the insulating layer 156B, the insulating layer 156C, and the insulating layer 175.

[0131] The conductive film 152f may be, for example, a conductive oxide, or may be a multilayer film.

[0132] Subsequently, as shown in FIG. 6B, the conductive film 152f is processed to form a conductive layer 152R, a conductive layer 152G, a conductive layer 152B, and a conductive layer 152C.

[0133] Subsequently, the organic compound film 103Rf is formed on the conductive layer 152R, the conductive layer 152G, the conductive layer 152B, and the insulating layer 175. Note that, as shown in FIG 6C, the organic compound film 103Rf is not formed on the conductive layer 152C.

[0134] Subsequently, as shown in FIG. 6C, a conductive film 106Rf, a protective film 158Rf, and a sacrificial film 159Rf are formed on the organic compound film 103Rf.

[0135] By providing the protective film 158Rf over the conductive film 106Rf, damage to the organic compound film 103Rf and the conductive film 106Rf during the manufacturing process of the display device can be reduced, and the reliability of the light-emitting device can be improved.

[0136] The protective film 158Rf is made of a film having high resistance to the processing conditions of the organic compound film 103Rf and the conductive film 106Rf, specifically, a film having a high etching selectivity with respect to the organic compound film 103Rf and the conductive film 106Rf. The sacrificial film 159Rf is made of a film having a high etching selectivity with respect to the protective film 158Rf and the conductive film 106Rf.

[0137] The protective film 158Rf and the sacrificial film 159Rf are formed at a temperature lower than the heat-resistant temperature of the organic compound film 103Rf. The substrate temperature when forming the protective film 158Rf and the sacrificial film 159Rf is typically 100° C. or higher and 200° C. or lower, preferably 100° C. or higher and 150° C. or lower, and more preferably 100° C. or higher and 120° C. or lower.

[0138] It is preferable that the protective film 158Rf and the sacrificial film 159Rf are made of a film that can be removed by wet etching or dry etching.

[0139] It is preferable that the protective film 158Rf formed near the organic compound film 103Rf is formed using a formation method that causes less damage to the organic compound film 103Rf than the sacrificial film 159Rf. For example, the ALD method or the vacuum deposition method is more preferable than the sputtering method.

[0140] As the protective film 158Rf and the sacrificial film 159Rf, for example, one or more of a metal film, an alloy film, a metal oxide film, a semiconductor film, an organic insulating film, and an inorganic insulating film can be used.

[0141] The protective film 158Rf and the sacrificial film 159Rf may be made of, for example, a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, or tantalum, or an alloy material containing the metal material. In particular, it is preferable to use a low melting point material such as aluminum or silver. It is preferable to use a metal material capable of blocking ultraviolet rays for one or both of the protective film 158Rf and the sacrificial film 159Rf, since it is possible to suppress irradiation of ultraviolet rays during pattern exposure to the organic compound film 103Rf, and thus to suppress deterioration of the organic compound film 103Rf.

[0142] Furthermore, for the protective film 158Rf and the sacrificial film 159Rf, metal oxides such as In-Ga-Zn oxide, indium oxide, In-Zn oxide, In-Sn oxide, indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), and indium tin oxide containing silicon can be used.

[0143] In addition, in the above metal oxide, an element M (M is one or more elements selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) may be used instead of gallium.

[0144] For the protective film 158Rf and the sacrificial film 159Rf, it is preferable to use a semiconductor material such as silicon or germanium because it has a high affinity with the semiconductor manufacturing process, or a compound containing the above semiconductor material may be used.

[0145] Moreover, various inorganic insulating films can be used as the protective film 158Rf and the sacrificial film 159Rf. In particular, an oxide insulating film is preferable because it has higher adhesion to the organic compound film 103Rf than a nitride insulating film. A nitride insulating film is preferable because it is dense and has high barrier performance. A silicon nitride film is particularly preferable as the nitride insulating film.

[0146] 6(C), a resist mask 190R is formed. The resist mask 190R can be formed by applying a photosensitive material (photoresist) and then performing exposure and development.

[0147] The resist mask 190R is provided in a position overlapping with the conductive layer 152R. The resist mask 190R is preferably provided also in a position overlapping with the conductive layer 152C, which can prevent the conductive layer 152C from being damaged during the manufacturing process of the display device.

[0148] Then, a part of the sacrificial film 159Rf is removed using the resist mask 190R to form a sacrificial layer 159R. The sacrificial layer 159R remains on the conductive layer 152R and the conductive layer 152C. Then, the resist mask 190R is removed. Then, a part of the protective film 158Rf is removed using the sacrificial layer 159R as a mask (also called a hard mask) to form a protective layer 158R.

[0149] By using the wet etching method, damage to the organic compound film 103Rf during processing of the protective film 158Rf and the sacrificial film 159Rf can be reduced compared to the case of using the dry etching method. When using the wet etching method, it is preferable to use an acid aqueous solution such as a developing solution, an alkaline aqueous solution such as a tetramethylammonium hydroxide (TMAH) aqueous solution, a dilute hydrofluoric acid, an oxalic acid, a phosphoric acid, an acetic acid, a nitric acid, or a mixed liquid thereof.

[0150] Furthermore, when dry etching is used in processing the protective film 158Rf, deterioration of the organic compound film 103Rf can be suppressed by not using an oxygen-containing gas as an etching gas.

[0151] The resist mask 190R can be removed in the same manner as the resist mask 191.

[0152] Subsequently, the conductive film 106Rf is processed to form the auxiliary electrode 106R. For example, the sacrificial layer 159R and the protective layer 158R are used as a hard mask to remove a part of the conductive film 106Rf to form the auxiliary electrode 106R.

[0153] Subsequently, the organic compound film 103Rf is processed to form the EL layer 103R. For example, the sacrificial layer 159R and the protective layer 158R are used as a hard mask to remove a part of the organic compound film 103Rf to form the EL layer 103R.

[0154] 6D, a laminated structure of the EL layer 103R, the auxiliary electrode 106R, the protective layer 158R, and the sacrificial layer 159R remains on the conductive layer 152R. Also, the conductive layers 152G and 152B are exposed.

[0155] The organic compound film 103Rf and the conductive film 106Rf are preferably processed by anisotropic etching, particularly anisotropic dry etching, or wet etching may be used.

[0156] When dry etching is used, deterioration of the organic compound film 103Rf can be suppressed by not using an oxygen-containing gas as an etching gas.

[0157] Moreover, a gas containing oxygen may be used as the etching gas. When the etching gas contains oxygen, the etching speed can be increased. Therefore, etching can be performed under low power conditions while maintaining a sufficiently high etching speed. This makes it possible to suppress damage to the organic compound film 103Rf. Furthermore, problems such as adhesion of reaction products generated during etching can be suppressed.

[0158] When using a dry etching method, it is preferable to use a gas containing one or more of H2, CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or a group 18 element such as He or Ar as an etching gas. Alternatively, it is preferable to use a gas containing one or more of these elements and oxygen as an etching gas. Alternatively, oxygen gas may be used as an etching gas.

[0159] Subsequently, an organic compound film 103Gf that will later become the EL layer 103G and a conductive film 106Gf that will later become the auxiliary electrode 106G are formed.

[0160] The organic compound film 103Gf can be formed by a method similar to that which can be used to form the organic compound film 103Rf.

[0161] 7A, a protective film 158Gf and a sacrificial film 159Gf are formed in this order. Then, a resist mask 190G is formed. The materials and forming methods of the protective film 158Gf and the sacrificial film 159Gf are the same as those applicable to the protective film 158Rf and the sacrificial film 159Rf. The materials and forming methods of the resist mask 190G are the same as those applicable to the resist mask 190R.

[0162] The resist mask 190G is preferably provided in a position overlapping with the conductive layer 152G.

[0163] Then, a part of the sacrificial film 159Gf is removed using the resist mask 190G to form a sacrificial layer 159G. The sacrificial layer 159G remains on the conductive layer 152G. Then, the resist mask 190G is removed. Then, a part of the protective film 158Gf is removed using the sacrificial layer 159G as a mask to form a protective layer 158G. Then, the organic compound film 103Gf is processed to form an EL layer 103G. As a result, as shown in FIG. 7B, a laminated structure of the EL layer 103G, the auxiliary electrode 106G, the protective layer 158G, and the sacrificial layer 159G remains on the conductive layer 152G. Also, the sacrificial layer 159R and the conductive layer 152B are exposed.

[0164] Subsequently, as shown in FIG. 7C, an organic compound film 103Bf which will later become the EL layer 103B is formed.

[0165] The organic compound film 103Bf can be formed by a method similar to that which can be used to form the organic compound film 103Rf.

[0166] 7(C), a protective film 158Bf and a sacrificial film 159Bf are formed in this order. Then, a resist mask 190B is formed. The materials and forming methods of the protective film 158Bf and the sacrificial film 159Bf are the same as those applicable to the protective film 158Rf and the sacrificial film 159Rf. The materials and forming methods of the resist mask 190B are the same as those applicable to the resist mask 190R.

[0167] The resist mask 190B is provided in a position overlapping with the conductive layer 152B.

[0168] 7(D), a part of the sacrificial film 159Bf is removed using a resist mask 190B to form a sacrificial layer 159B. The sacrificial layer 159B preferably remains on the conductive layer 152B. Then, the resist mask 190B is removed. Then, a part of the protective film 158Bf is removed using the sacrificial layer 159B as a mask to form a protective layer 158B. Then, the organic compound film 103Bf is processed to form the EL layer 103B. For example, a part of the organic compound film 103Bf is removed using the sacrificial layer 159B and the protective layer 158B as a hard mask to form the EL layer 103B.

[0169] 7D, a laminated structure of the EL layer 103B, the protective layer 158B, and the sacrificial layer 159B remains on the conductive layer 152B. Also, the sacrificial layers 159R and 159G are exposed.

[0170] It is preferable that the side surfaces of the EL layer 103R, the EL layer 103G, and the EL layer 103B are perpendicular or approximately perpendicular to the surface on which they are formed. For example, it is preferable that the angle between the surface on which they are formed and these side surfaces is 60 degrees or more and 90 degrees or less.

[0171] As described above, the distance between two adjacent ones of the EL layer 103R, the EL layer 103G, and the EL layer 103B formed by the photolithography method can be narrowed to 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. For example, by using an exposure device for LSI, the distance can be narrowed to 500 nm or less, 200 nm or less, 100 nm or less, or even 50 nm or less. Here, the distance can be defined, for example, as the distance between two adjacent opposing ends of the EL layer 103R, the EL layer 103G, and the EL layer 103B. In this way, by narrowing the distance between the island-like EL layers, a display device having high definition and a large aperture ratio can be provided. In addition, the distance between the first electrodes between adjacent light-emitting devices can also be narrowed, for example, to 10 μm or less, 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. For example, by using an exposure tool for LSIs, the spacing can be narrowed to 500 nm or less, 200 nm or less, 100 nm or less, or even 50 nm or less.

[0172] Next, as shown in FIG. 8(A), it is preferable to remove the sacrificial layers 159R, 159G, and 159B.

[0173] The sacrificial layer can be removed by the same method as the sacrificial film processing method. In particular, by using a wet etching method, damage to the EL layer 103R, the EL layer 103G, and the EL layer 103B during the removal of the sacrificial layer can be reduced compared to the case of using a dry etching method.

[0174] The sacrificial layer may also be removed by dissolving it in a polar solvent such as water or alcohol, such as ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin.

[0175] After removing the sacrificial layer, a drying treatment may be performed to remove water adsorbed on the surface. For example, a heat treatment can be performed in an inert gas atmosphere or a reduced pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50° C. to 200° C., preferably 60° C. to 150° C., more preferably 70° C. to 120° C. A reduced pressure atmosphere is preferable because it allows drying at a lower temperature.

[0176] Subsequently, as shown in FIG. 8(B), an insulating film 125af which will later become the second insulating layer 125a is formed.

[0177] Subsequently, as shown in FIG. 8C, an insulating film 127f, which will later become the first insulating layer 127, is formed on the insulating film 125af.

[0178] The insulating films 125af and 127f are preferably formed by a method that causes less damage to the EL layers. In particular, since the insulating film 125af is formed in contact with the side surfaces of the EL layers, it is preferably formed by a method that causes less damage to the EL layers than the insulating film 127f.

[0179] The insulating films 125af and 127f are formed at a temperature lower than the heat resistance temperature of each EL layer. By increasing the substrate temperature during film formation, the insulating film 125af can have a low impurity concentration and a high barrier property against at least one of water and oxygen even if it is thin.

[0180] The substrate temperature when forming the insulating films 125af and 127f is preferably 60° C. or more, 80° C. or more, 100° C. or more, or 120° C. or more, and 200° C. or less, 180° C. or less, 160° C. or less, 150° C. or less, or 140° C. or less, respectively.

[0181] As the insulating film 125af, it is preferable to form an insulating film having a thickness of 5 nm or more, or 10 nm or more, and 200 nm or less, 150 nm or less, 100 nm or less, 50 nm or less, 30 nm or less, or 20 nm or less, within the above-mentioned substrate temperature range.

[0182] The insulating film 125af is preferably formed by, for example, the ALD method. By using the ALD method, film damage can be reduced and a film with high coverage can be formed, which is preferable. In addition, the insulating film 125af is preferably formed by using an aluminum oxide film by the ALD method. Alternatively, the insulating film 125af is preferably formed by using a PEALD method. When the PEALD method is used, it is preferable that a film with high coverage and a film with high barrier properties can be formed. For example, the insulating film 125af is preferably formed by using a silicon nitride film by the PEALD method. Alternatively, the insulating film 125af is preferably formed by forming an aluminum oxide film by the ALD method and then forming a silicon-based insulating film, particularly a silicon nitride film, by the PEALD method.

[0183] The insulating film 127f is preferably formed by using the above-mentioned wet film formation method. The insulating film 127f is preferably formed by using a photosensitive material, for example, by spin coating, and more specifically, is preferably formed by using a photosensitive resin composition containing an acrylic resin.

[0184] Next, exposure is performed to expose a part of the insulating film 127f to visible light or ultraviolet light. The first insulating layer 127 is formed in a region sandwiched between any two of the conductive layers 152R, 152G, and 152B, and around the conductive layer 152C.

[0185] The width of the first insulating layer 127 to be formed later can be controlled by the exposed region of the insulating film 127f. In this embodiment, the first insulating layer 127 is processed so as to have a portion overlapping with the upper surface of the conductive layer 151.

[0186] The light used for exposure preferably contains i-line (wavelength 365 nm), and may contain at least one of g-line (wavelength 436 nm) and h-line (wavelength 405 nm).

[0187] Subsequently, as shown in FIG. 9(A), development is performed to remove the exposed area of ​​the insulating film 127f, thereby forming the first insulating layer 127a.

[0188] Next, the entire substrate is exposed to light, and the first insulating layer 127a is preferably irradiated with visible light or ultraviolet light. The energy density of the exposure is 0 mJ / cm 2 Larger, 800mJ / cm 2 It is preferable to set the concentration to 0 mJ / cm or less. 2 Larger than 500mJ / cm 2 It is more preferable to set the following. By performing such exposure after development, the transparency of the first insulating layer 127 can be improved in some cases. Also, the substrate temperature required for the heat treatment for transforming the first insulating layer 127a into a tapered shape in a later step can be reduced in some cases.

[0189] Here, the presence of a barrier insulating layer against oxygen (e.g., an aluminum oxide film, a silicon nitride film, etc.) as protective layer 158R, protective layer 158G, and protective layer 158B, and insulating film 125af can reduce the diffusion of oxygen into EL layer 103R, EL layer 103G, and EL layer 103B.

[0190] Next, a heat treatment (also referred to as post-baking) is performed. By performing the heat treatment, the first insulating layer 127a can be transformed into the first insulating layer 127 having a tapered shape on the side surface (FIG. 9B). The heat treatment is performed at a temperature lower than the heat resistance temperature of the EL layer. The heat treatment can be performed at a substrate temperature of 50° C. to 200° C., preferably 60° C. to 150° C., more preferably 70° C. to 130° C. The heating atmosphere may be an air atmosphere or an inert gas atmosphere. The heating atmosphere may be an atmospheric pressure atmosphere or a reduced pressure atmosphere. This can improve the adhesion between the first insulating layer 127 and the second insulating layer 125a and also improve the corrosion resistance of the first insulating layer 127.

[0191] By providing the protective layers 158R, 158G, and 158B and the insulating film 125af on the EL layers 103R, 103G, and 103B, the EL layers 103R, 103G, and 103B can be prevented from being damaged and deteriorated during the heat treatment, thereby improving the reliability of the light-emitting device.

[0192] Next, a photomask is formed on the first insulating layer 127, and an etching process is performed to remove a part of the insulating film 125af. As a result, a second insulating layer 125a is formed under the first insulating layer 127 (FIG. 9(C)). Note that, hereinafter, this etching process may be referred to as a first etching process.

[0193] The first etching process can be performed by dry etching or wet etching.

[0194] When dry etching is performed, it is preferable to use a chlorine-based gas. As the chlorine-based gas, Cl2, BCl3, SiCl4, CCl4, etc. can be used alone or in a mixture of two or more gases. In addition, oxygen gas, hydrogen gas, helium gas, argon gas, etc. can be appropriately added to the above chlorine-based gas, either alone or in a mixture of two or more gases.

[0195] As the dry etching apparatus, a dry etching apparatus having a high density plasma source can be used. As the dry etching apparatus having a high density plasma source, for example, an inductively coupled plasma (ICP) etching apparatus can be used. Alternatively, a capacitively coupled plasma (CCP) etching apparatus having parallel plate electrodes can be used.

[0196] In addition, it is preferable to perform the first etching process by wet etching. By using the wet etching method, damage to the EL layer 103R, the EL layer 103G, and the EL layer 103B can be reduced compared to the case of using the dry etching method. For example, the wet etching can be performed using an alkaline solution. For example, an alkaline solution such as TMAH can be used for wet etching of an aluminum oxide film. Also, an acid solution containing fluoride can be used. In this case, the wet etching can be performed by the paddle method.

[0197] In the first etching process, it is preferable to select an etching method that can obtain a selectivity between the protective layers 158R, 158G, and 158B and the insulating film 125af.

[0198] 10(A), an etching process is performed using the second insulating layer 125a and the first insulating layer 127 as a mask to remove parts of the protective layer 158R, the protective layer 158G, and the protective layer 158B. As a result, openings are formed in the protective layer 158R, the protective layer 158G, and the protective layer 158B, respectively, and the upper surfaces of the auxiliary electrode 106R, the auxiliary electrode 106G, the EL layer 103B, and the conductive layer 152C are exposed. Note that, hereinafter, this etching process may be referred to as a second etching process.

[0199] The second etching process is performed by wet etching. By using the wet etching method, damage to the auxiliary electrode 106R, the auxiliary electrode 106G, and the EL layer 103B can be reduced compared to the case of using the dry etching method. The wet etching can be performed using, for example, an alkaline solution or an acidic solution. It is preferable to use an aqueous solution so that the EL layer 103B does not dissolve.

[0200] 10(B), the common layer 107 and the second electrode 102 are formed on the auxiliary electrode 106R, the auxiliary electrode 106G, the EL layer 103B, the conductive layer 152C, and the first insulating layer 127. The common layer 107 and the second electrode 102 can be formed by a method such as a sputtering method or a vacuum deposition method.

[0201] 10(C), a protective layer 131 is formed over the second electrode 102. The protective layer 131 can be formed by a method such as a vacuum deposition method, a sputtering method, a CVD method, or an ALD method. In particular, when the PEALD method is used, a film with high barrier properties can be formed at a low temperature.

[0202] Subsequently, the substrate 120 is bonded onto the protective layer 131 using the resin layer 122, whereby the display device can be manufactured.

[0203] As described above, in the manufacturing method of the display device according to one embodiment of the present invention, the island-shaped EL layer 103R, the island-shaped EL layer 103G, and the island-shaped EL layer 103B are formed by forming a film on one surface and then processing it, instead of using a fine metal mask, so that the island-shaped layers can be formed with a uniform thickness. As a result, a high-definition display device or a display device with a high aperture ratio can be realized. Even if the definition or aperture ratio is high and the distance between the subpixels is extremely short, the EL layer 103R, the EL layer 103G, and the EL layer 103B can be prevented from contacting each other in adjacent subpixels. Therefore, leakage current can be prevented from occurring between the subpixels. As a result, crosstalk can be prevented, and a display device with extremely high contrast can be realized. Even in a display device including a light-emitting device manufactured by a photolithography method, a display device with good characteristics can be provided.

[0204] The structure of this embodiment mode can be used in appropriate combination with other structures.

[0205] (Embodiment 3) In this embodiment, the configuration of an organic EL element, which is a light-emitting device having an EL layer, will be described with reference to Fig. 11. The organic EL element is a light-emitting device including a configuration including an EL layer having a light-emitting layer between a first electrode 101 and a second electrode 102.

[0206] One of the first electrode 101 and the second electrode 102 functions as an anode, and the other functions as a cathode. FIG 11 illustrates an example in which the first electrode 101 is the anode.

[0207] The anode is preferably formed using a metal, alloy, conductive compound, or mixture thereof having a large work function (specifically, 4.0 eV or more). Specific examples include indium oxide-tin oxide (ITO), indium oxide-tin oxide containing silicon or silicon oxide (ITSO), indium oxide-zinc oxide, and indium oxide containing tungsten oxide and zinc oxide (IWZO). These conductive metal oxide films are usually formed by a sputtering method, but may also be formed by applying a sol-gel method or the like. As an example of a method for forming indium oxide-zinc oxide, a method for forming indium oxide-zinc oxide by a sputtering method using a target in which 1 to 20 wt % of zinc oxide is added to indium oxide may be used. Indium oxide containing tungsten oxide and zinc oxide (IWZO) can also be formed by sputtering using a target containing 0.5 to 5 wt% tungsten oxide and 0.1 to 1 wt% zinc oxide relative to indium oxide. Other materials used for the anode include, for example, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), titanium (Ti), aluminum (Al), or nitrides of metal materials (for example, titanium nitride). A layer of these laminated materials may also be used as the anode. For example, a film laminated in the order of Al, Ti, and ITSO on Ti is preferable because it has a good reflectance, is highly efficient, and can achieve high resolution of several thousand ppi. Alternatively, graphene can also be used as a material used for the anode. In addition, by using a composite material capable of forming the hole injection layer 111 described later as a layer in contact with the anode (typically a hole injection layer), it becomes possible to select an electrode material regardless of the work function.

[0208] The hole injection layer 111 is provided in contact with the anode and has a function of facilitating the injection of holes into the EL layer 103. The hole injection layer 111 can be formed of a phthalocyanine-based compound or complex compound such as phthalocyanine (abbreviation: HPc) or copper phthalocyanine (abbreviation: CuPc), an aromatic amine compound such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB) or 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), or a polymer compound such as poly(3,4-ethylenedioxythiophene) / (polystyrenesulfonic acid) (abbreviation: PEDOT / PSS).

[0209] The hole injection layer 111 may be formed of a substance having electron acceptor properties. As the substance having electron acceptor properties, an organic compound having an electron-withdrawing group (such as a halogen group or a cyano group) can be used, and examples of the substance include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile, and the like. In particular, compounds in which an electron-withdrawing group is bonded to a condensed aromatic ring having multiple heteroatoms, such as HAT-CN, are thermally stable and preferred. Radialene derivatives having an electron-withdrawing group (especially a halogen group such as a fluoro group, a cyano group, etc.) [3] are preferred because they have a very high electron-accepting property, and specific examples include α,α',α''-1,2,3-cyclopropane triylidene tris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropane triylidene tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], and α,α',α''-1,2,3-cyclopropane triylidene tris[2,3,4,5,6-pentafluorobenzeneacetonitrile]. As the substance having electron acceptor properties, in addition to the organic compounds described above, transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide can be used.

[0210] In addition, the hole-injection layer 111 is preferably formed using a composite material containing the above-mentioned material having an electron acceptor property and an organic compound having a hole-transport property.

[0211] As the organic compound having a hole transporting property used in the composite material, various organic compounds such as aromatic amine compounds, heteroaromatic compounds, aromatic hydrocarbons, and polymer compounds (oligomers, dendrimers, polymers, etc.) can be used. Note that the organic compound having a hole transporting property used in the composite material is preferably 1×10 -6 cm 2 It is preferable that the organic compound has a hole mobility of 1000 nm or more / Vs. The organic compound having hole transport properties used in the composite material is preferably a compound having a condensed aromatic hydrocarbon ring or a π-electron-rich heteroaromatic ring. As the condensed aromatic hydrocarbon ring, an anthracene ring, a naphthalene ring, etc. are preferable. As the π-electron-rich heteroaromatic ring, a condensed aromatic ring containing at least one of a pyrrole skeleton, a furan skeleton, and a thiophene skeleton in the ring is preferable, and specifically, a carbazole ring, a dibenzothiophene ring, or a ring in which an aromatic ring or a heteroaromatic ring is further condensed to the above rings is preferable.

[0212] Such organic compounds having hole transport properties preferably have any of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton. In particular, the organic compounds may be aromatic amines having a substituent containing a dibenzofuran ring or a dibenzothiophene ring, aromatic monoamines having a naphthalene ring, or aromatic monoamines in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group. It is preferable that the organic compounds having hole transport properties are substances having an N,N-bis(4-biphenyl)amino group, because this allows the manufacture of a light-emitting device with a long life.

[0213] Specific examples of organic compounds having hole transport properties as described above include N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4′-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4′′-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophene-4-yl)phenyl]-4-amino-p-terphenyl ]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4′,4″-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4′,4″-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4′-diphenyl-4″-(6;1′-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4′-diphenyl-4″-(7;1′-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβ NB-03), 4,4′-diphenyl-4′′-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4′-diphenyl-4′′-(6;2′-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4′-diphenyl-4′′-(7;2′-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4′-diphenyl-4′′-(4;2′-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4′-Diphenyl-4′′-(5;2′-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4′-(2-naphthyl)-4′′-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4′-[4-(2-naphthyl)phenyl]-4′′-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4′-[4-(2-naphthyl)phenyl] 4,4′-diphenyl-4′′-[4′-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4′-[4-(3-phenyl-9H-carbazol-9-yl)furan-4′′-phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4′-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4′-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4′-diphenyl-4′′-[4′-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4′-[4-(3-phenyl-9H-carbazol-9-yl)furan-4′′-phenyltriphenylamine (abbreviation: TPBiAβNBi), N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9′-spirobi[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N- Bis(biphenyl-4-yl)-9,9′-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(biphenyl-4-yl)-9,9′-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9′-spirobi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(biphenyl-4-yl)-N-(9,9-Dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3′-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4′ -[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-phenyl-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4′-diphenyl-4′′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4′- Di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviation: PCBBiF), N,N-bis( 9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-1-amine, etc. can be mentioned.

[0214] In addition, as a material having hole transport properties, other aromatic amine compounds such as N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), and 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B) can also be used.

[0215] By forming the hole injection layer 111, the hole injection property is improved, and a light emitting device with a low driving voltage can be obtained.

[0216] Among substances having an electron acceptor property, an organic compound having an electron acceptor property is an easy-to-use material because it can be easily evaporated and formed into a film.

[0217] The hole transport layer 112 is formed by including an organic compound having a hole transport property. -6 cm 2 It is preferable that the hole mobility is 1 / Vs or more.

[0218] Examples of the material having the hole transport property include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviation: TPD), N,N'-bis(9,9'-spirobi[9H-fluorene]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluorene-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'- (9-Phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4′-diphenyl-4′′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4′-di(1-naphthyl)-4′′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), Compounds with aromatic amine skeletons such as 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), and N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9′-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4′-di(N-carbazolyl)benzene, bazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 9,9′-diphenyl-9H,9′H-3,3′-bicarbazole (abbreviation: PCCP), 9,9′-bis(biphenyl-4-yl)-3,3′-bi-9H-carbazole (abbreviation: BisBPCz), 9,9′-bis(biphenyl-3-yl)-3,3′-bi-9H-carbazole (abbreviation: BismBPCz), 9-(biphenyl-3-yl)-9′-(biphenyl-4-yl)-9H,9′H-3,3′-bicarbazole (abbreviation: mBPCCBP), 9-(2-naphthyl)-9′-phenyl-9H,9′H-3,3′-bicarbazole (abbreviation: βNCCP), 9-(3-biphenyl)-9′-(2-naphthyl)-3,3′-bi-9H-carbazole (abbreviation: βNCCmBP), 9-(4-biphenyl)-9′-(2-naphthyl)-3,3′-bi-9H-carbazole (abbreviation: βNCCBP), 9,9′-di-2-naphthyl-3,3′-9H,9′H-bicarbazole (abbreviation: BisβNCz), 9-( 2-naphthyl)-9'-[1,1':4',1"-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1"-terphenyl]-5'-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':4',1"-terphenyl]-4-yl-3,3'-9H,9'H- Bicarbazole, 9-(2-naphthyl)-9′-[1,1′:3′,1”-terphenyl]-4-yl-3,3′-9H,9′H-bicarbazole, 9-(2-naphthyl)-9′-(triphenylen-2-yl)-3,3′-9H,9′H-bicarbazole, 9-phenyl-9′-(triphenylen-2-yl)-3,3′-9H,9′H-bicarbazole (abbreviation: PCCzTp), 9,9′-bis(triphenylen-2-yl)-3,3′-9H,9′H-bicarbazole, 9-(4-biphenyl)- Compounds with a carbazole skeleton such as 9'-(triphenylen-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(triphenylen-2-yl)-9'-[1,1':3',1"-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, and 9-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]phenanthrene (abbreviation: PCPPn), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,Examples of the compounds include compounds having a thiophene skeleton such as 8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III) and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), and compounds having a furan skeleton such as 4,4′,4″-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II). Among the above, compounds having an aromatic amine skeleton and compounds having a carbazole skeleton are preferable because they have good reliability, high hole transportability, and contribute to reducing the driving voltage. Note that the substances exemplified as the materials having hole transport properties used for the composite material of the hole injection layer 111 can also be suitably used as the material for forming the hole transport layer 112.

[0219] The light-emitting layer 113 is a layer containing a light-emitting substance, and preferably contains a light-emitting substance and a host material. The light-emitting layer 113 may contain other materials at the same time. The light-emitting layer 113 may also be a laminate of two layers with different compositions.

[0220] The luminescent material may be a fluorescent material, a phosphorescent material, a material exhibiting thermally activated delayed fluorescence (TADF), or any other luminescent material.

[0221] Examples of materials that can be used as the fluorescent substance in the light-emitting layer include the following: In addition, fluorescent substances other than these can also be used.

[0222] 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2,2′-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4′-(10-phenyl-9-anthryl)biphenyl-4-yl]-2,2′-bipyridine (abbreviation: PAPP2BPy), N,N′-diphenyl-N,N′-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N′-bis(3-methylphenyl)-N,N′-bis[3-(9-phenyl-9H-fluoren-9-yl )phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-( 10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), N,N′′-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis(N,N′,N′-triphenyl-1,4-phenylenediamine) (abbreviation: DPABPA), N,9 -Diphenyl-N-[4-(9,10-diphenyl-2-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: 2PCAPPA), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N′,N′-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), N,N,N′,N′,N′′,N′′,N′′′,N′′′-octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), Coumarin 30, N-(9,10-diphenyl-2-anthryl)-N,9-Diphenyl-9H-carbazol-3-amine (abbreviation: 2PCAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N′,N′-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,N′,N′-triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA) , 9,10-bis(biphenyl-2-yl)-N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracen-9-amine (abbreviation: DPhAPhA), Coumarin 545T, N,N′-diphenylquinacridone (abbreviation: DPQd), rubrene, 5,12-bis(biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyrazol-2-yl)-1,1-diphenylquinacridone (abbreviation: DPQd), DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (DCM2), N,N,N′,N′-tetrakis(4-methylphenyl)tetracene-5,11-diamine (p-mPhTD), 7,14-diphenyl-N,N,N′,N′-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation Name: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB),6-Bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJTM), N,N′-diphenyl-N,N′-(1,6-pyrene-diyl)bis[(6-phenylbenzo[b ]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10PCA2Nbf(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02), etc. In particular, condensed aromatic diamine compounds such as pyrene diamine compounds, such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03, are preferred because they have high hole trapping properties and excellent luminous efficiency or reliability.

[0223] In addition, 5,9-diphenyl-5,9-diaza-13b-boranaphtho[3,2,1-de]anthracene (abbreviation: DABNA1), 9-(diphenyl-3-yl)-N,N,5,11-tetraphenyl-5,9-dihydro-5,9-diaza-13b-boranaphtho[3,2,1-de]anthracene-3-amine (abbreviation: DABNA2), 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl)-N,N-diphenyl-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborine -7-amine (abbreviation: DPhA-tBu4DABNA), 2,12-di(tert-butyl)-N,N,5,9-tetra(4-tert-butylphenyl)-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborine-7-amine (abbreviation: tBuDPhA-tBu4DABNA), 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl)-7-methyl-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborine (abbreviation: Me-tBu4DABNA), N 7 ,N 7 ,N 13 ,N 13 Condensed heteroaromatic compounds containing nitrogen and boron, such as 5,9,11,15-octaphenyl-5H,9H,11H,15H-[1,4]benzazaborino[2,3,4-kl][1,4]benzazaborino[4',3',2':4,5][1,4]benzazaborino[3,2-b]phenazaborine-7,13-diamine (abbreviation: ν-DABNA) and 2-(4-tert-butylphenyl)benz[5,6]indolo[3,2,1-jk]benzo[b]carbazole (abbreviation: tBuPBibc), in particular compounds having a diaza-boranaphtho-anthracene skeleton, can be preferably used because they have a narrow emission spectrum and can emit blue light with good color purity.

[0224] In addition to these, 9,10,11-tris[3,6-bis(1,1-dimethylethyl)-9H-carbazolyl-9-yl]-2,5,15,18-tetrakis(1,1-dimethylethyl)indolo[3,2,1-de]indolo[3′,2′,1′:8,1][1,4]benzazaborino[2,3,4-kl]phenazaborine (abbreviation: BBCz-G), 9,11-bis[3,6-bis(1,1-dimethylethyl)-9H-carbazolyl-9-yl]-2,5,15,18-tetrakis(1,1-dimethylethyl)indolo[3,2,1-de]indolo[3′,2′,1′:8,1][1,4]benzazaborino[2,3,4-kl]phenazaborine (abbreviation: BBCz-Y) and the like can be preferably used.

[0225] When a phosphorescent material is used as the light-emitting material in the light-emitting layer, examples of materials that can be used include the following.

[0226] Organometallic iridium complexes having a 4H-triazole skeleton, such as 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]) and tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Mptz)3]); Organometallic iridium complexes with 1H-triazole skeletons such as tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(Mptz1-mp)3]) and tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Prptz1-Me)3]), fac-tris[1-(2,6-di isopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpim)3]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me)3]), tris(2-{1-[2,6-bis(1-methylethyl)phenyl]-1H-imidazol-2-yl-κN3}-4-cyano organometallic iridium complexes with an imidazole skeleton, such as tris[(6-tert-butyl-3-phenyl-2H-imidazo[4,5-b]pyrazin-1-yl-κC2)phenyl-κC]iridium(III) (abbreviation: [Ir(cb)3]), organometallic complexes with a benzimidazolidene skeleton, such as bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2′ ]iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4′,6′-difluorophenyl)pyridinato-N,C 2′ ]iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3′,5′-bis(trifluoromethyl)phenyl]pyridinato-N,C 2′}Iridium(III) picolinate (abbreviation: [Ir(CF3ppy)2(pic)]), bis[2-(4′,6′-difluorophenyl)pyridinato-N,C 2′ ] Organometallic iridium complexes with phenylpyridine derivatives having electron-withdrawing groups as ligands, such as iridium(III) acetylacetonate (abbreviated as FIracac), are examples of such compounds that exhibit blue phosphorescence and have a peak emission wavelength in the range of 450 nm to 520 nm.

[0227] In addition, tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)3]), tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)3]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)2(acac)]), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)2(acac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm)2(acac)]), (acetylacetonato)bis[5-methyl-6- Organometallic iridium complexes having a pyrimidine skeleton, such as (2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(mpmppm)2(acac)]) and (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2(acac)]); organometallic iridium complexes having a pyrazine skeleton, such as (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-Me)2(acac)]) and (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-iPr)2(acac)]); 2′) Iridium(III) (abbreviation: [Ir(ppy)3]), bis(2-phenylpyridinato-N,C 2′ )iridium(III) acetylacetonate (abbreviation: [Ir(ppy)2(acac)]), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: [Ir(bzq)2(acac)]), tris(benzo[h]quinolinato)iridium(III) (abbreviation: [Ir(bzq)3]), tris(2-phenylquinolinato-N,C 2′ ) Iridium(III) (abbreviation: [Ir(pq)3]), bis(2-phenylquinolinato-N,C 2′)iridium(III) acetylacetonate (abbreviation: [Ir(pq)2(acac)]), [2-d3-methyl-8-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) (abbreviation: [Ir(5mppy-d3)2(mbfpypy-d3)]), [2-d3-methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) zofro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy)2(mbfpypy-d3)]), tris{2-[5-(methyl-d3)-4-phenyl-2-pyridinyl-κN]phenyl-κC}iridium(III) (abbreviation: [Ir(5m4dppy-d3)3]), [2-(4-d3-methyl-5-phenyl-2-pyridinyl-κN 2) [2-methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy)2(mbfpypy)]), [2-methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy)2(mbfpypy)]), In addition to organometallic iridium complexes having a pyridine skeleton such as (4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium (abbreviated as [Ir(ppy)2(mdppy)]), rare earth metal complexes such as tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviated as [Tb(acac)3(Phen)]) can be mentioned. These are compounds that mainly exhibit green phosphorescence and have a peak emission in the wavelength range from 500 nm to 600 nm. In addition, organometallic iridium complexes having a pyrimidine skeleton are particularly preferred because they are also remarkably excellent in reliability or luminous efficiency.

[0228] In addition, organometallic iridium complexes having a pyrimidine skeleton, such as (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(5mdppm)2(dpm)]), and bis[4,6-di(naphthalen-1-yl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(d1npm)2(dpm)]); Organometallic iridium complexes with a pyrazine skeleton, such as (acetylacetonato)bis(2,3,5-triphenylpyrazinate)iridium(III) (abbreviation: [Ir(tppr)2(acac)]), bis(2,3,5-triphenylpyrazinate)(dipivaloylmethanato)iridium(III) (abbreviation: [Ir(tppr)2(dpm)]), and (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq)2(acac)]), tris(1-phenylisoquinolinato-N,C 2′ ) Iridium(III) (abbreviation: [Ir(piq)3]), bis(1-phenylisoquinolinato-N,C 2′Organometallic iridium compounds with pyridine skeletons such as (3,7-diethyl-4,6-nonanedionato-κO4,κO6)bis[2,4-dimethyl-6-[7-(1-methylethyl)-1-isoquinolinyl-κN]phenyl-κC]iridium(III) and (3,7-diethyl-4,6-nonanedionato-κO4,κO6)bis[2,4-dimethyl-6-[5-(1-methylethyl)-2-quinolinyl-κN]phenyl-κC]iridium(III). In addition to iridium complexes, platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (abbreviation: PtOEP), tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: [Eu(DBM)3(Phen)]), tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: [Eu(TTA)3(Phen)]) are examples of rare earth metal complexes. These are compounds that exhibit red phosphorescence and have a peak emission in the wavelength range from 600 nm to 700 nm. In addition, organometallic iridium complexes with a pyrazine skeleton can emit red light with good chromaticity.

[0229] In addition to the above-mentioned phosphorescent compounds, known phosphorescent compounds may be selected and used.

[0230] TADF materials include fullerene and its derivatives, acridine and its derivatives, eosin derivatives, etc. Also included are metal-containing porphyrins including magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), palladium (Pd), etc. Examples of the metal-containing porphyrin include protoporphyrin-tin fluoride complex (SnF2(Proto IX)), mesoporphyrin-tin fluoride complex (SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (SnF2(Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complex (SnF2(OEP)), etioporphyrin-tin fluoride complex (SnF2(Etio I)), and octaethylporphyrin-platinum chloride complex (PtCl2OEP), which are shown in the following structural formulas.

[0231] [ka]

[0232] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9′-phenyl-9H,9′H-3,3′-bicarbazole (abbreviation: PCCzTzn), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), Heterocyclic compounds having one or both of a π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring, such as 3-[4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviation: DMAC-DPS), and 10-phenyl-10H,10′H-spiro[acridin-9,9′-anthracene]-10′-one (abbreviation: ACRSA), can also be used. The heterocyclic compound has a π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring, and therefore has high electron transport and hole transport properties, and is therefore preferred. Among the skeletons having a π-electron deficient heteroaromatic ring, the pyridine skeleton, the diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), and the triazine skeleton are preferred because they are stable and reliable. In particular, the benzofuropyrimidine skeleton, the benzothienopyrimidine skeleton, the benzofuropyrazine skeleton, and the benzothienopyrazine skeleton are preferred because they have high electron acceptor properties and good reliability. In addition, among the skeletons having a π-electron rich heteroaromatic ring, the acridine skeleton, the phenoxazine skeleton, the phenothiazine skeleton, the furan skeleton, the thiophene skeleton, and the pyrrole skeleton are preferred because they are stable and reliable.In addition, the furan skeleton is preferably a dibenzofuran skeleton, and the thiophene skeleton is preferably a dibenzothiophene skeleton. In addition, the pyrrole skeleton is particularly preferably an indole skeleton, a carbazole skeleton, an indolocarbazole skeleton, a bicarbazole skeleton, or a 3-(9-phenyl-9H-carbazol-3-yl)-9H-carbazole skeleton. In addition, a substance in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded is particularly preferable because the electron donating property of the π-electron-rich heteroaromatic ring and the electron accepting property of the π-electron-deficient heteroaromatic ring are both strong, and the energy difference between the S1 level and the T1 level is small, so that thermally activated delayed fluorescence can be efficiently obtained. In addition, an aromatic ring to which an electron-withdrawing group such as a cyano group is bonded may be used instead of the π-electron-deficient heteroaromatic ring. In addition, an aromatic amine skeleton, a phenazine skeleton, or the like can be used as the π-electron-rich skeleton. In addition, examples of the π-electron-deficient skeleton that can be used include a xanthene skeleton, a thioxanthene dioxide skeleton, an oxadiazole skeleton, a triazole skeleton, an imidazole skeleton, an anthraquinone skeleton, a boron-containing skeleton such as phenylborane or boranthrene, an aromatic ring having a nitrile group or a cyano group such as benzonitrile or cyanobenzene, a heteroaromatic ring, a carbonyl skeleton such as benzophenone, a phosphine oxide skeleton, a sulfone skeleton, etc. In this way, a π-electron-deficient skeleton and a π-electron-rich skeleton can be used in place of at least one of a π-electron-deficient heteroaromatic ring and a π-electron-rich heteroaromatic ring.

[0233] [ka]

[0234] TADF materials are materials that have a small difference between the S1 and T1 levels and have the function of converting triplet excitation energy to singlet excitation energy by reverse intersystem crossing. Therefore, triplet excitation energy can be upconverted to singlet excitation energy by a small amount of thermal energy (reverse intersystem crossing), and singlet excitation states can be generated efficiently. In addition, triplet excitation energy can be converted into light emission.

[0235] In addition, exciplexes (also called exciplexes), which form an excited state with two types of substances, have an extremely small difference between the S1 level and the T1 level and function as TADF materials that can convert triplet excitation energy into singlet excitation energy.

[0236] As an index of the T1 level, a phosphorescence spectrum observed at low temperatures (for example, 77 K to 10 K) may be used. For a TADF material, when a tangent line is drawn at the base of the short wavelength side of the fluorescence spectrum, and the energy of the wavelength of the extrapolated line is defined as the S1 level, and a tangent line is drawn at the base of the short wavelength side of the phosphorescence spectrum, and the energy of the wavelength of the extrapolated line is defined as the T1 level, the difference between the S1 level and the T1 level is preferably 0.3 eV or less, and more preferably 0.2 eV or less.

[0237] In addition, when a TADF material is used as a light-emitting material, the S1 level of the host material is preferably higher than the S1 level of the TADF material, and the T1 level of the host material is preferably higher than the T1 level of the TADF material.

[0238] As the host material of the light-emitting layer, various carrier transporting materials such as a material having an electron transporting property and / or a material having a hole transporting property, or the above-mentioned TADF material can be used.

[0239] As the material having hole transport properties, an organic compound having an amine skeleton, a π-electron-rich heteroaromatic ring skeleton, etc. is preferable. As the π-electron-rich heteroaromatic ring, a condensed aromatic ring containing at least one of an acridine skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a furan skeleton, a thiophene skeleton, and a pyrrole skeleton in the ring is preferable, and specifically, a carbazole ring, a dibenzothiophene ring, or a ring in which an aromatic ring or a heteroaromatic ring is further condensed to the above is preferable.

[0240] Such organic compounds having hole transport properties preferably have any of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton. In particular, the organic compounds may be aromatic amines having a substituent containing a dibenzofuran ring or a dibenzothiophene ring, aromatic monoamines having a naphthalene ring, or aromatic monoamines in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group. It is preferable that the organic compounds having hole transport properties are substances having an N,N-bis(4-biphenyl)amino group, because this allows the manufacture of a light-emitting device with a long life.

[0241] Examples of such organic compounds include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviation: TPD), N,N'-bis(9,9'-spirobi[9H-fluoren]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3′-(9-phenylfluoren-9-yl)triphenylamine (abbreviated as mBPAFLP), 4-phenyl-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviated as PCBA1BP), 4,4′-diphenyl-4′′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviated as PCBBi1BP), 4-(1-naphthyl)-4′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviated as PC Aromatic amines such as 4,4′-di(1-naphthyl)-4′′-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), and N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9′-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF) Compounds with a carbazole skeleton, such as 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4′-di(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), and 9,9′-diphenyl-9H,9′H-3,3′-bicarbazole (abbreviation: PCCP), 4,4′,4′′-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,Examples of the compounds include compounds having a thiophene skeleton such as 8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III) and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), and compounds having a furan skeleton such as 4,4′,4″-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II). Among the above, compounds having an aromatic amine skeleton or compounds having a carbazole skeleton are preferable because they have good reliability, high hole transportability, and contribute to reducing the driving voltage. In addition, the organic compounds listed as examples of materials having hole transportability in the hole transport layer can also be used.

[0242] Examples of materials having electron transport properties include metal complexes such as bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2), 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: ZnPBO), and bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ), and organic compounds having a π-electron-deficient heteroaromatic ring skeleton. Examples of organic compounds having a π-electron-deficient heteroaromatic ring skeleton include organic compounds containing a heteroaromatic ring having a polyazole skeleton, organic compounds containing a heteroaromatic ring having a pyridine skeleton, organic compounds containing a heteroaromatic ring having a diazine skeleton, and organic compounds containing a heteroaromatic ring having a triazine skeleton.

[0243] Among them, organic compounds containing a heteroaromatic ring having a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), organic compounds containing a heteroaromatic ring having a pyridine skeleton, and organic compounds containing a heteroaromatic ring having a triazine skeleton are preferable because of their good reliability. In particular, organic compounds containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing a heteroaromatic ring having a triazine skeleton have high electron transport properties and contribute to reducing the driving voltage. In addition, benzofuropyrimidine skeleton, benzothienopyrimidine skeleton, benzofuropyrazine skeleton, and benzothienopyrazine skeleton are preferable because of their high electron acceptor properties and good reliability.

[0244] Examples of organic compounds having a π-electron-deficient heteroaromatic ring skeleton include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole- Organic compounds with an azole skeleton, such as 3,5-bis[3-(9H-carbazol-9-yl)phenyl]-9H-carbazole (abbreviation: CO11), 2,2′,2″-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), and 4,4′-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs), )phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), bathophenanthroline (abbreviation: Bphen), bathocuproine (abbreviation: BCP), 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), 2-[3-(2-triphenylenyl)phenyl]-1,10 -phenanthroline (abbreviation: mTpPPhen), 2-phenyl-9-(2-triphenylenyl)-1,10-phenanthroline (abbreviation: Ph-TpPhen), 2-[4-(9-phenanthrenyl)-1-naphthalenyl]-1,10-phenanthroline (abbreviation: PnNPhen), 2-[4-(2-triphenylenyl)phenyl]-1,10-phenanthroline (abbreviation: pTpPPhen), and other organic compounds containing heteroaromatic rings with a pyridine skeleton, such as 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3′-(dibenzothiophene-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3′-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4′-(9-phenyl-9H-carbazol-3-yl)-3,1′-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), 2-[4 -(3,6-diphenyl-9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 9-[3′-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1′,2′:4,5]furo[2,3- b]pyrazine (abbreviation: 9mDBtBPNfpr), 9-[3′-(dibenzothiophen-4-yl)biphenyl-4-yl]naphtho[1′,2′:4,5]furo[2,3-b]pyrazine (abbreviation: 9pmDBtBPNfpr), 4,6-bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(dibenzothiophen-4-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine pyrimidine (abbreviation: 4,6mCzP2Pm), 9,9′-[pyrimidine-4,6-diylbis(biphenyl-3,3′-diyl)]bis(9H-carbazole) (abbreviation: 4,6mCzBP2Pm), 8-(biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 8-(1,1':4',1''-terphenyl-3-yl-2,4,5,6,2',3',5',6',2'',3'',4'',5'',6''-d, 13)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm-d 13), 3,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzofuro[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3′-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1′,2′:4,5]furo[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2′-binaphthalene)-6-yl]-4-[ 3-(Dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm), 2,2′-(pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6(P-Bqn)2Py), 2,2′-(pyridine-2,6-diyl)bis{4-[4-(2-naphthyl)phenyl]-6-phenylpyrimidine} (abbreviation: 2,6(NP-PPm)2Py), 6-(biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]- nyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 2,6-bis(4-naphthalen-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 7-[4-(9-phenyl-9H-carbazol-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: PC-cgD organic compounds with a diazine skeleton such as 2-(biphenyl-4-yl)-4-phenyl-6-(9,9′-spirobi[9H-fluoren]-2-yl)-1,3,5-triazine (abbreviation: BP-SFTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn), and 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn-02), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9′-phenyl-2,3′-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 2-[3′-(9,9-dimethyl-9H-fluorene-2-yl)phenyl]- mFBPTzn), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-{3-[3-(dibenzothiophene-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTzn), 2,4,6-tris[3′-( pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), 2-[3-(2,6-dimethyl-3-pyridinyl)-5-(9-phenanthrenyl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTzn), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazin-2-yl]-11,12-dihydro-12-phenylindolo[2,3-a]carbazole (abbreviation: BP-Icz( II)Tzn), 2-[3′-(triphenylen-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mTpBPTzn), 3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-(biphenyl-3-yl)-4-phenyl-6-{8-[(1,1′:4′,1′′-terphenyl)-4-yl]-1-dibenzofuranyl}-1,3,Examples of such organic compounds include organic compounds containing a heteroaromatic ring having a triazine skeleton, such as 5-triazine (abbreviation: mBP-TPDBfTzn). In addition, organic compounds containing a heteroaromatic ring having a diazine skeleton, organic compounds containing a heteroaromatic ring having a pyridine skeleton, and organic compounds containing a heteroaromatic ring having a triazine skeleton are preferred because of their high reliability. In particular, organic compounds containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing a heteroaromatic ring having a triazine skeleton have high electron transport properties and contribute to reducing the driving voltage.

[0245] As a TADF material that can be used as a host material, the same TADF materials listed above can be used. When a TADF material is used as a host material, the triplet excitation energy generated in the TADF material is converted to singlet excitation energy by reverse intersystem crossing, and the energy is then transferred to the light-emitting material, thereby increasing the light-emitting efficiency of the light-emitting device. In this case, the TADF material functions as an energy donor, and the light-emitting material functions as an energy acceptor.

[0246] This is very effective when the luminescent material is a fluorescent luminescent material. In this case, in order to obtain high luminous efficiency, the S1 level of the TADF material is preferably higher than the S1 level of the fluorescent luminescent material. In addition, the T1 level of the TADF material is preferably higher than the S1 level of the fluorescent luminescent material. Therefore, the T1 level of the TADF material is preferably higher than the T1 level of the fluorescent luminescent material.

[0247] It is also preferable to use a TADF material that emits light that overlaps with the wavelength of the lowest energy absorption band of the fluorescent material, because this allows for smooth transfer of excitation energy from the TADF material to the fluorescent material, resulting in efficient emission.

[0248] In addition, in order to efficiently generate singlet excitation energy from triplet excitation energy by reverse intersystem crossing, it is preferable that carrier recombination occurs in the TADF material. In addition, it is preferable that the triplet excitation energy generated in the TADF material does not transfer to the triplet excitation energy of the fluorescent material. For this purpose, it is preferable that the fluorescent material has a protective group around the luminophore (skeleton causing light emission) of the fluorescent material. As the protective group, a substituent having no π bond is preferable, and a saturated hydrocarbon is preferable, specifically, an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a trialkylsilyl group having 3 to 10 carbon atoms are mentioned, and it is more preferable that there are a plurality of protective groups. Since a substituent having no π bond has poor function of transporting carriers, the distance between the TADF material and the luminophore of the fluorescent material can be increased without affecting carrier transport or carrier recombination. Here, the luminophore refers to an atomic group (skeleton) causing light emission in the fluorescent material. The luminophore preferably has a skeleton having a π bond, preferably contains an aromatic ring, and preferably has a condensed aromatic ring or a condensed heteroaromatic ring. Examples of such luminophore include a phenanthrene skeleton, a stilbene skeleton, an acridone skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, a chrysene skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, and a naphthobisbenzofuran skeleton. In particular, fluorescent substances having a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, a chrysene skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, and a naphthobisbenzofuran skeleton are preferred because they have a high fluorescence quantum yield.

[0249] When a fluorescent emitting material is used as the emitting material, a material having an anthracene skeleton is suitable as the host material. When a material having an anthracene skeleton is used as the host material of the fluorescent emitting material, it is possible to realize an emitting layer having both good luminous efficiency and durability. As a material having an anthracene skeleton to be used as the host material, a material having a diphenylanthracene skeleton, particularly a 9,10-diphenylanthracene skeleton, is preferable because it is chemically stable. In addition, when the host material has a carbazole skeleton, it is preferable because the injection and transport properties of holes are improved, but when the host material contains a benzocarbazole skeleton in which a benzene ring is further condensed to the carbazole skeleton, the HOMO level is about 0.1 eV shallower than that of a host material having a carbazole skeleton, making it easier for holes to enter, and is more preferable. In particular, when the host material contains a dibenzocarbazole skeleton, it is preferable because the HOMO level is about 0.1 eV shallower than that of a host material having a carbazole skeleton, making it easier for holes to enter, and it also has excellent hole transport properties and high heat resistance. Therefore, a more preferable host material is a substance having both a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzocarbazole skeleton or a dibenzocarbazole skeleton). From the viewpoint of the hole injection / transport property, a benzofluorene skeleton or a dibenzofluorene skeleton may be used instead of the carbazole skeleton.Examples of such substances include 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA), 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 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′- 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviation: α,βADN), 2-(10-phenylanthracen-9-yl)dibenzofuran, 2-(10-phenyl-9-anthracenyl)benzo Zo[b]naphtho[2,3-d]furan (abbreviation: Bnf(II)PhA), 9-(2-naphthyl)-10-[3-(2-naphthyl)phenyl]anthracene (abbreviation: βN-mβNPAnth), 1-{4-[10-(biphenyl-4-yl)-9-anthracenyl]phenyl}-2-ethyl-1H-benzimidazole (abbreviation: EtBImPBPhA), etc. In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA are preferred choices because they show very good properties.

[0250] The host material may be a mixture of a plurality of substances, and when a mixture of host materials is used, it is preferable to mix a material having an electron transporting property with a material having a hole transporting property. By mixing a material having an electron transporting property with a material having a hole transporting property, the transporting property of the light-emitting layer 113 can be easily adjusted, and the recombination region can be easily controlled. The weight ratio of the content of the material having a hole transporting property to the material having an electron transporting property may be 1:19 to 19:1 (material having a hole transporting property:material having an electron transporting property).

[0251] A phosphorescent material can be used as a part of the mixed material. The phosphorescent material can be used as an energy donor that provides excitation energy to a fluorescent material when the fluorescent material is used as a light-emitting material.

[0252] In addition, these mixed materials may form an exciplex. It is preferable to select a combination that forms an exciplex that emits light that overlaps with the wavelength of the lowest energy absorption band of the light-emitting material, because this makes energy transfer smooth and allows efficient light emission. In addition, the use of this structure is preferable because the driving voltage is reduced.

[0253] At least one of the materials forming the exciplex may be a phosphorescent material, which allows the triplet excitation energy to be efficiently converted into singlet excitation energy by reverse intersystem crossing.

[0254] As a combination of materials that efficiently form an exciplex, it is preferable that the HOMO level of the material having hole transport properties is equal to or higher than the HOMO level of the material having electron transport properties. It is also preferable that the LUMO level of the material having hole transport properties is equal to or higher than the LUMO level of the material having electron transport properties. The LUMO level and HOMO level of the material can be derived from the electrochemical properties (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV) measurement.

[0255] The formation of an exciplex can be confirmed, for example, by comparing the emission spectrum of a material having hole transport properties, the emission spectrum of a material having electron transport properties, and the emission spectrum of a mixed film obtained by mixing these materials, and observing the phenomenon that the emission spectrum of the mixed film shifts to a longer wavelength than the emission spectrum of each material (or has a new peak on the longer wavelength side). Alternatively, the formation of an exciplex can be confirmed by comparing the transient photoluminescence (PL) of a material having hole transport properties, the transient PL of a material having electron transport properties, and the transient PL of a mixed film obtained by mixing these materials, and observing the difference in transient response, such as the transient PL lifetime of the mixed film having a longer lifetime component than the transient PL lifetime of each material, or the proportion of delayed components becoming larger. The above-mentioned transient PL may also be read as transient electroluminescence (EL). That is, the formation of an exciplex can also be confirmed by comparing the transient EL of a material having hole transport properties, the transient EL of a material having electron transport properties, and the transient EL of a mixed film obtained by mixing these materials, and observing the difference in transient response.

[0256] The electron transport layer 114 is a layer containing a substance having an electron transport property. The substance having an electron transport property is a layer containing a substance having an electron mobility of 1×10 -7 cm 2 / Vs or more, preferably 1×10 -6 cm 2A substance having an electron mobility of 100 / Vs or more is preferred. Note that, other substances can be used as long as they have a higher transportability of electrons than holes. In addition, an organic compound having a π-electron-deficient heteroaromatic ring skeleton is preferred. Examples of organic compounds having a π-electron-deficient heteroaromatic ring skeleton include organic compounds containing a heteroaromatic ring having a polyazole skeleton, organic compounds containing a heteroaromatic ring having a pyridine skeleton, organic compounds containing a heteroaromatic ring having a diazine skeleton, and organic compounds containing a heteroaromatic ring having a triazine skeleton. Among them, organic compounds containing a heteroaromatic ring having a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton) or organic compounds containing a heteroaromatic ring having a pyridine skeleton, and organic compounds containing a heteroaromatic ring having a triazine skeleton are preferred because of their good reliability. In particular, organic compounds containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton, and organic compounds containing a heteroaromatic ring having a triazine skeleton have high electron transportability and contribute to reducing the driving voltage. Moreover, a benzofuropyrimidine skeleton, a benzothienopyrimidine skeleton, a benzofuropyrazine skeleton, and a benzothienopyrazine skeleton are preferable because they have high acceptor properties and good reliability.

[0257] Examples of such organic compounds include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO 11), organic compounds with an azole skeleton such as 2,2′,2″-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), and 4,4′-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs), 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)phenyl]pyridine (abbreviation: 35DCzPPy), and lysyl)phenyl]benzene (abbreviation: TmPyPB), bathophenanthroline (abbreviation: Bphen), bathocuproine (abbreviation: BCP), 2,9-di(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), 2-[3-(2-triphenylenyl)phenyl]-1,10-phenanthroline (abbreviation: mTpPPhen), 2-phenyl-9-(2-triphenylenyl)-1,10-phenanthroline (abbreviation: mTpPPhen), Organic compounds containing heteroaromatic rings with a pyridine skeleton, such as 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3′-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3′-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3′-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4′-(9-phenyl-9H-carbazol-3-yl)-3,1′-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), 2-[4-(3,6-diphenyl-9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: :2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 9-[3′-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1′,2′:4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 9-[3′-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1′,2′:4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 4,6-Bis[3-(dibenzothiophen-4-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-Bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP ... ), 9,9′-[pyrimidine-4,6-diylbis(biphenyl-3,3′-diyl)]bis(9H-carbazole) (abbreviation: 4,6mCzBP2Pm), 8-(biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 8-(1,1':4',1''-terphenyl-3-yl-2,4,5,6,2',3',5',6',2'',3'',4'',5'',6''-d, 13 )-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm-d 13), 3,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzofuro[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3′-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1′,2′:4,5]furo[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2′-binaphthalene)-6-yl]-4-[ 3-(Dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm), 2,2′-(pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6(P-Bqn)2Py), 2,2′-(pyridine-2,6-diyl)bis{4-[4-(2-naphthyl)phenyl]-6-phenylpyrimidine} (abbreviation: 2,6(NP-PPm)2Py), 6-(biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]- nyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 2,6-bis(4-naphthalen-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 7-[4-(9-phenyl-9H-carbazol-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: PC-cgD organic compounds with a diazine skeleton such as 2-(biphenyl-4-yl)-4-phenyl-6-(9,9′-spirobi[9H-fluoren]-2-yl)-1,3,5-triazine (abbreviation: BP-SFTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn), and 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn-02), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9′-phenyl-2,3′-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 2-[3′-(9,9-dimethyl-9H-fluorene-2-yl)phenyl]- mFBPTzn), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-{3-[3-(dibenzothiophene-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTzn), 2,4,6-tris[3′-( pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), 2-[3-(2,6-dimethyl-3-pyridinyl)-5-(9-phenanthrenyl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTzn), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazin-2-yl]-11,12-dihydro-12-phenylindolo[2,3-a]carbazole (abbreviation: BP-Icz( II)Tzn), 2-[3′-(triphenylen-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mTpBPTzn), 3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-(biphenyl-3-yl)-4-phenyl-6-{8-[(1,1′:4′,1′′-terphenyl)-4-yl]-1-dibenzofuranyl}-1,3,Among organic compounds containing a heteroaromatic ring having a triazine skeleton such as 5-triazine (abbreviation: mBP-TPDBfTzn), it is preferable to use an organic compound that does not contain a condensed aromatic ring composed only of six-membered rings, or an organic compound that does not have a structure in which two or more six-membered aromatic hydrocarbon rings are condensed adjacent to each other, a structure in which two or more six-membered heteroaromatic rings are condensed adjacent to each other, or a structure in which one or more six-membered aromatic hydrocarbon rings and one six-membered heteroaromatic ring are condensed adjacent to each other.

[0258] Among them, organic compounds containing heteroaromatic rings having a diazine skeleton, organic compounds containing heteroaromatic rings having a pyridine skeleton, and organic compounds containing heteroaromatic rings having a triazine skeleton are preferred because they have good reliability. In particular, organic compounds containing heteroaromatic rings having a diazine (pyrimidine or pyrazine) skeleton, and organic compounds containing heteroaromatic rings having a triazine skeleton are preferred because they have high electron transport properties and contribute to reducing driving voltage. In particular, organic compounds having a phenanthroline skeleton such as mTpPPhen, PnNPhen, and mPPhen2P are preferred, and organic compounds having a phenanthroline dimer structure such as mPPhen2P are more preferred because they have excellent stability.

[0259] The electron transport layer 114 may have a laminated structure. A layer in the electron transport layer 114 having a laminated structure that is in contact with the light-emitting layer 113 may function as a hole blocking layer. When the electron transport layer in contact with the light-emitting layer is made to function as a hole blocking layer, it is preferable to use a material whose HOMO level is deeper than the HOMO level of the material contained in the light-emitting layer 113 by 0.5 eV or more.

[0260] The electron injection layer 115 may be a layer containing an alkali metal or alkaline earth metal compound or complex, such as lithium fluoride, 8-hydroxyquinolinato-lithium (abbreviation: Liq), a mixed material of lithium fluoride and ytterbium, a mixture thereof, or 1,1'-pyridine-2,6-diyl-bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) (abbreviation: hpp2Py), etc. The electron injection layer 115 may be a layer made of a material having an electron transporting property containing the above-mentioned material.

[0261] Alternatively, a charge generation layer 116 may be provided instead of the electron injection layer 115 (FIG. 11(B)). The charge generation layer 116 is a layer capable of injecting holes into a layer in contact with the cathode side of the layer and electrons into a layer in contact with the anode side of the layer by applying a potential. The charge generation layer 116 includes at least a P-type layer 117. The P-type layer 117 is preferably formed using the composite material listed above as a material capable of forming the hole injection layer 111. The P-type layer 117 may also be formed by laminating a film containing an acceptor material and a film containing a hole transport material, both of which are materials that constitute the composite material. By applying a potential to the P-type layer 117, electrons are injected into the electron transport layer 114 and holes are injected into the cathode, and the organic EL element operates.

[0262] In addition, the charge generating layer 116 preferably includes, in addition to the P-type layer 117, either or both of an electron relay layer 118 and an electron injection buffer layer 119.

[0263] The electron relay layer 118 contains at least a substance having electron transport properties, and has a function of preventing interaction between the electron injection buffer layer 119 and the P-type layer 117 to smoothly transfer electrons. The LUMO level of the substance having electron transport properties contained in the electron relay layer 118 is preferably between the LUMO level of the acceptor substance in the P-type layer 117 and the LUMO level of the substance contained in the layer in contact with the charge generation layer 116 in the electron transport layer 114. The specific energy level of the LUMO level of the substance having electron transport properties used in the electron relay layer 118 is -5.0 eV or more, preferably -5.0 eV or more and -3.0 eV or less. Note that, as the substance having electron transport properties used in the electron relay layer 118, it is preferable to use a phthalocyanine-based material such as phthalocyanine (abbreviation: HPc), copper phthalocyanine (abbreviation: CuPc), zinc phthalocyanine (abbreviation: ZnPc), or a metal complex having a metal-oxygen bond and an aromatic ligand.

[0264] The electron injection buffer layer 119 can be made of a material with high electron injection properties, such as an alkali metal, an alkaline earth metal, a rare earth metal, or a compound thereof (an alkali metal compound (including an oxide such as lithium oxide, a halide such as lithium fluoride, or a carbonate such as lithium carbonate or cesium carbonate), an alkaline earth metal compound (including an oxide, a halide, or a carbonate), or a rare earth metal compound (including an oxide, a halide, or a carbonate)).

[0265] In addition, when the electron-injection buffer layer 119 is formed containing a substance having an electron-transporting property and a donor substance, as the donor substance, an alkali metal, an alkaline earth metal, a rare earth metal, and a compound thereof (an alkali metal compound (including an oxide such as lithium oxide, a halide such as lithium fluoride, or a carbonate such as lithium carbonate or cesium carbonate), an alkaline earth metal compound (including an oxide, a halide, or a carbonate), or a rare earth metal compound (including an oxide, a halide, or a carbonate)) can be used, as well as an organic compound such as tetrathianaphthacene (abbreviation: TTN), nickelocene, or decamethylnickelocene. Note that as the substance having an electron-transporting property, a material similar to the material constituting the electron-transporting layer 114 described above can be used.

[0266] Note that, as described in Embodiment 1, an auxiliary electrode can be provided between the electron injection layer 115 and the second electrode 102 or between the charge generation layer 116 and the second electrode 102, which is preferable because optical adjustment can be performed.

[0267] The second electrode 102 is an electrode including a cathode. The second electrode 102 may have a laminated structure, in which case a layer in contact with the EL layer 103 functions as the cathode. As a material for forming the cathode, a metal, an alloy, an electrically conductive compound, a mixture thereof, or the like having a small work function (specifically, 3.8 eV or less) can be used. Specific examples of such a cathode material include alkali metals such as lithium (Li) or cesium (Cs), elements belonging to Group 1 or Group 2 of the periodic table such as magnesium (Mg), calcium (Ca), and strontium (Sr), and alloys (Mg:Ag, Al:Li) and compounds (lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), etc.) containing these, rare earth metals such as europium (Eu), ytterbium (Yb), and alloys containing these, etc. However, by providing the electron injection layer 115 or a thin film of the above-mentioned material with a small work function between the second electrode 102 and the electron transport layer, various conductive materials such as Al, Ag, ITO, indium oxide-tin oxide containing silicon or silicon oxide can be used as the cathode regardless of the magnitude of the work function.

[0268] When the second electrode 102 is formed using a material that is transparent to visible light, a light-emitting device that emits light from the second electrode 102 side can be obtained.

[0269] These conductive materials can be formed into a film by a dry method such as a vacuum deposition method or a sputtering method, an inkjet method, a spin coating method, etc. Also, they may be formed by a wet method using a sol-gel method, or may be formed by a wet method using a paste of a metal material.

[0270] In addition, various methods, whether dry or wet, can be used to form the EL layer 103. For example, a vacuum deposition method, a gravure printing method, an offset printing method, a screen printing method, an inkjet method, or a spin coating method may be used.

[0271] Moreover, the above-mentioned electrodes or layers may be formed using different film formation methods.

[0272] Next, an embodiment of a light-emitting device having a structure in which a plurality of light-emitting units are stacked (also called a stacked element or a tandem element) will be described with reference to FIG. 11(C). This organic EL element has a plurality of light-emitting units between an anode and a cathode. One light-emitting unit has a structure almost similar to that of the EL layer 103 shown in FIG. 11(A). In other words, it can be said that the organic EL element shown in FIG. 11(C) is an organic EL element having a plurality of light-emitting units, and the organic EL element shown in FIG. 11(A) or FIG. 11(B) is an organic EL element having one light-emitting unit.

[0273] 11(C), a first light-emitting unit 511 and a second light-emitting unit 512 are stacked between a first electrode 501 and a second electrode 502, and a charge generation layer 513 is provided between the first light-emitting unit 511 and the second light-emitting unit 512. The first electrode 501 and the second electrode 502 correspond to the first electrode 101 and the second electrode 102 in FIG. 11(A), respectively, and the same as those described in the description of FIG. 11(A) can be applied to them. The first light-emitting unit 511 and the second light-emitting unit 512 may have the same structure or different structures.

[0274] The charge generation layer 513 has a function of injecting electrons into one light-emitting unit and injecting holes into the other light-emitting unit when a voltage is applied between the first electrode 501 and the second electrode 502. That is, in the case of FIG. 11C, when a voltage is applied so that the potential of the anode is higher than the potential of the cathode, the charge generation layer 513 may inject electrons into the first light-emitting unit 511 and inject holes into the second light-emitting unit 512.

[0275] The charge generation layer 513 is preferably formed to have the same structure as the charge generation layer 116 described in FIG. 11B. A composite material of an organic compound and a metal oxide has excellent carrier injection and carrier transport properties, and therefore can realize low-voltage driving and low-current driving. When the anode side surface of the light-emitting unit is in contact with the charge generation layer 513, the charge generation layer 513 can also function as a hole injection layer of the light-emitting unit, and therefore the light-emitting unit does not need to be provided with a hole injection layer.

[0276] Furthermore, when an electron injection buffer layer 119 is provided in the charge generation layer 513, the electron injection buffer layer 119 plays the role of an electron injection layer in the light-emitting unit on the anode side, so that it is not necessarily necessary to form an electron injection layer in the light-emitting unit on the anode side.

[0277] 11C, an organic EL element having two light-emitting units has been described, but the present invention can be applied to an organic EL element having three or more light-emitting units stacked together. By disposing a plurality of light-emitting units between a pair of electrodes and separating them with a charge generating layer 513 as in the organic EL element according to this embodiment, it is possible to realize an element that can emit light with high luminance while keeping the current density low and has a long life. In addition, it is possible to realize a display device that can be driven at a low voltage and has low power consumption.

[0278] In addition, by making the emission colors of the respective light-emitting units different, it is possible to obtain light emission of a desired color from the organic EL element as a whole. For example, in an organic EL element having two light-emitting units, it is possible to obtain an organic EL element that emits white light as a whole by obtaining red and green emission colors from the first light-emitting unit and blue emission color from the second light-emitting unit.

[0279] In addition, each layer and electrode such as the above-mentioned EL layer 103, the first light-emitting unit 511, the second light-emitting unit 512, and the charge generation layer can be formed by using, for example, a deposition method (including a vacuum deposition method), a droplet discharge method (also called an ink-jet method), a coating method, a gravure printing method, etc. In addition, they may contain a low molecular weight material, a medium molecular weight material (including an oligomer and a dendrimer), or a polymer material.

[0280] 12 shows two adjacent light-emitting devices (light-emitting device 130a and light-emitting device 130b) in a light-emitting device group including a plurality of light-emitting devices 130 included in a display device according to one embodiment of the present invention. Note that the display device includes a plurality of first electrodes (101a, 101b), a second electrode 102, a plurality of EL layers (104a, 104b), and a common layer 107 formed on an insulating layer 175, and the light-emitting devices include at least the first electrodes (101a, 101b), the EL layers (104a, 104b), the common layer 107, and the second electrode 102 that overlap each other.

[0281] The light-emitting device 130a has an EL layer 103a between the first electrode 101a on the insulating layer 175 and the opposing second electrode 102. The EL layer 103a has a hole injection layer 111a, a hole transport layer 112a, a light-emitting layer 113a, an electron transport layer 114a, and a common layer 107, but may have a different laminated structure. The EL layer 103a may have an independent EL layer 104a for each light-emitting device, and may further have a common layer 107 shared by a plurality of light-emitting devices. In FIG. 12, the hole injection layer 111a, the hole transport layer 112a, the light-emitting layer 113a, and the electron transport layer 114a correspond to the EL layer 104a. Note that a layer having the same function as the common layer may be provided as an independent configuration for each light-emitting device, and the common layer 107 may not be provided.

[0282] The light-emitting device 130b has an EL layer 103b between the first electrode 101b on the insulating layer 175 and the opposing second electrode 102. The EL layer 103b has a hole injection layer 111b, a hole transport layer 112b, a light-emitting layer 113b, an electron transport layer 114b, and a common layer 107, but may have a different laminated structure. In FIG. 12, the hole injection layer 111b, the hole transport layer 112b, the light-emitting layer 113b, and the electron transport layer 114b correspond to the EL layer 104b. Note that a layer having the same function as the common layer may be provided as an independent structure for each light-emitting device, and the common layer 107 may not be provided.

[0283] It is preferable that the second electrode 102 is a continuous layer (common layer) shared by the light-emitting device 130a and the light-emitting device 130b. The EL layers 103a and 103b other than the common layer 107, i.e., the EL layers 104a and 104b, are processed using photolithography after the electron transport layer 114a and the electron transport layer 114b are formed, respectively, and are therefore independent of each other. The end (outline) of the EL layer 103a other than the common layer 107 is processed using photolithography, so that it roughly coincides with the direction perpendicular to the substrate. The end (outline) of the EL layer 103b other than the common layer 107 is processed using photolithography, so that it roughly coincides with the direction perpendicular to the substrate.

[0284] In addition, the distance d between the first electrode 101a and the first electrode 101b can be made smaller than that when mask deposition is performed because the EL layer is processed using a photolithography method, and can be made 50 nm or more and 5 μm or less.

[0285] Note that the configuration of this embodiment mode can be used in appropriate combination with configurations of other embodiments.

[0286] (Embodiment 4) In this embodiment, a display device according to one embodiment of the present invention will be described.

[0287] The display device of the present embodiment can be a high-definition display device. Therefore, the display device of the present embodiment can be used for, for example, a display unit of a wristwatch-type or bracelet-type information terminal (wearable device), a VR device such as a head-mounted display (HMD), and a head-mounted wearable device such as a glasses-type AR device.

[0288] The display device of the present embodiment can be a high-resolution display device or a large-sized display device. Therefore, the display device of the present embodiment can be used in electronic devices having relatively large screens, such as television devices, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as in the display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and sound reproducing devices.

[0289] [Display module] 13A shows a perspective view of a display module 280. The display module 280 includes a display device 100A and an FPC 290. Note that the display device included in the display module 280 is not limited to the display device 100A, and may be any of a display device 100B and a display device 100D described later.

[0290] The display module 280 has a substrate 291 and a substrate 292. The display module 280 has a display unit 281. The display unit 281 is a region that displays an image in the display module 280, and is a region where light from each pixel provided in a pixel unit 284 described later can be viewed.

[0291] 13(B) shows a perspective view that typically illustrates the configuration on the substrate 291 side. A circuit portion 282, a pixel circuit portion 283 on the circuit portion 282, and a pixel portion 284 on the pixel circuit portion 283 are laminated on the substrate 291. A terminal portion 285 for connecting to an FPC 290 is provided in a portion of the substrate 291 that does not overlap with the pixel portion 284. The terminal portion 285 and the circuit portion 282 are electrically connected by a wiring portion 286 that is composed of a plurality of wirings.

[0292] The pixel section 284 has a plurality of pixels 284a arranged periodically. An enlarged view of one pixel 284a is shown on the right side of Fig. 13(B). The various configurations described in the previous embodiment can be applied to the pixel 284a. Fig. 13(B) shows an example in which the pixel 284a has the same configuration as the pixel 178 shown in Fig. 1.

[0293] The pixel circuit section 283 has a plurality of pixel circuits 283a that are periodically arranged.

[0294] One pixel circuit 283a is a circuit that controls the driving of a plurality of elements included in one pixel 284a.

[0295] The circuit portion 282 includes a circuit for driving each pixel circuit 283a of the pixel circuit portion 283. For example, it is preferable that the circuit portion 282 includes one or both of a gate line driver circuit and a source line driver circuit. In addition, the circuit portion 282 may include at least one of an arithmetic circuit, a memory circuit, a power supply circuit, and the like.

[0296] The FPC 290 functions as wiring for supplying a video signal, a power supply potential, or the like from the outside to the circuit portion 282. In addition, an IC may be mounted on the FPC 290.

[0297] Since the display module 280 can be configured such that one or both of the pixel circuit portion 283 and the circuit portion 282 are stacked below the pixel portion 284, the aperture ratio (effective display area ratio) of the display portion 281 can be made extremely high.

[0298] Such a display module 280 has extremely high resolution and can be suitably used in VR devices such as HMDs or glasses-type AR devices. For example, even in a configuration in which the display unit of the display module 280 is viewed through a lens, the display module 280 has an extremely high resolution display unit 281, so that pixels are not visible even when the display unit is enlarged with a lens, and a highly immersive display can be performed. In addition, the display module 280 is not limited to this and can be suitably used in electronic devices having a relatively small display unit.

[0299] [Display device 100A] The display device 100A shown in FIG. 14A includes a substrate 301, a light emitting device 130R, a light emitting device 130G, a light emitting device 130B, a capacitor 240, and a transistor 310.

[0300] The substrate 301 corresponds to the substrate 291 in FIGS. 13A and 13B. The transistor 310 is a transistor having a channel formation region in the substrate 301. For example, a semiconductor substrate such as a single crystal silicon substrate can be used as the substrate 301. The transistor 310 includes a part of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region in which the substrate 301 is doped with impurities and functions as a source or drain. The insulating layer 314 is provided to cover a side surface of the conductive layer 311.

[0301] In addition, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301 .

[0302] In addition, an insulating layer 261 is provided to cover the transistor 310 , and a capacitor 240 is provided on the insulating layer 261 .

[0303] Capacitor 240 has conductive layer 241, conductive layer 245, and insulating layer 243 located therebetween. Conductive layer 241 functions as one electrode of capacitor 240, conductive layer 245 functions as the other electrode of capacitor 240, and insulating layer 243 functions as a dielectric of capacitor 240.

[0304] The conductive layer 241 is provided over the insulating layer 261 and is embedded in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source and the drain of the transistor 310 by a plug 271 embedded in the insulating layer 261. The insulating layer 243 is provided to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping with the conductive layer 241 with the insulating layer 243 interposed therebetween.

[0305] An insulating layer 255 is provided covering the capacitor 240, an insulating layer 174 is provided on the insulating layer 255, and an insulating layer 175 is provided on the insulating layer 174. Light-emitting device 130R, light-emitting device 130G, and light-emitting device 130B are provided on the insulating layer 175. An insulator is provided in the region between adjacent light-emitting devices.

[0306] An auxiliary electrode 106R is located on the EL layer 103R, a protective layer 158R is located on the auxiliary electrode 106R, an auxiliary electrode 106G is located on the EL layer 103G, a protective layer 158G is located on the auxiliary electrode 106G, an auxiliary electrode 106B is located on the EL layer 103B, and a protective layer 158B is located on the auxiliary electrode 106B.

[0307] The conductive layer 151R, the conductive layer 151G, and the conductive layer 151B are electrically connected to one of the source or the drain of the transistor 310 via an insulating layer 243, an insulating layer 255, an insulating layer 174, a plug 256 embedded in the insulating layer 175, a conductive layer 241 embedded in the insulating layer 254, and a plug 271 embedded in the insulating layer 261. Various conductive materials can be used for the plug.

[0308] Further, a protective layer 131 is provided on the light emitting devices 130R, 130G, and 130B. The substrate 120 is bonded onto the protective layer 131 by a resin layer 122. For details of the components from the light emitting devices 130 to the substrate 120, refer to other embodiments. The substrate 120 corresponds to the substrate 292 in FIG. 13(A).

[0309] Fig. 14(B) is a modified example of the display device 100A shown in Fig. 14(A). The display device shown in Fig. 14(B) has a colored layer 132R, a colored layer 132G, and a colored layer 132B, and the light-emitting device 130 has an area overlapping one of the colored layer 132R, the colored layer 132G, and the colored layer 132B. In the display device shown in Fig. 14(B), the light-emitting device 130 can emit, for example, white light. Also, for example, the colored layer 132R can transmit red light, the colored layer 132G can transmit green light, and the colored layer 132B can transmit blue light.

[0310] [Display device 100B] FIG. 15 shows a perspective view of the display device 100B, and FIG. 16 shows a cross-sectional view of the display device 100B.

[0311] The display device 100B has a configuration in which a substrate 352 and a substrate 351 are bonded together. In Fig. 15, the substrate 352 is indicated by a dashed line.

[0312] The display device 100B has a pixel unit 177, a connection unit 140, a circuit 356, wiring 355, etc. Fig. 15 shows an example in which an IC 354 and an FPC 353 are mounted on the display device 100B. Therefore, the configuration shown in Fig. 15 can also be called a display module having the display device 100B, an IC (integrated circuit), and an FPC. Here, a display device having a connector such as an FPC attached to a substrate, or a display device having an IC mounted on the substrate, is called a display module.

[0313] The connection section 140 is provided outside the pixel section 177. There may be one or more connection sections 140. The connection section 140 electrically connects the common electrode of the light emitting device and the conductive layer, and can supply a potential to the common electrode.

[0314] The circuit 356 can be, for example, a scanning line driver circuit.

[0315] The wiring 355 has a function of supplying signals and power to the pixel portion 177 and the circuit 356. The signals and power are input to the wiring 355 from the outside via the FPC 353 or from the IC 354.

[0316] 15 shows an example in which an IC 354 is provided on a substrate 351 by a chip on glass (COG) method or a chip on film (COF) method. For example, an IC having a scanning line driver circuit or a signal line driver circuit can be used as the IC 354. Note that the display device 100B and the display module may not include an IC. Also, the IC may be mounted on an FPC by a COF method, for example.

[0317] FIG. 16 shows an example of a cross section of the display device 100B, in which a portion of the region including the FPC 353, a portion of the circuit 356, a portion of the pixel portion 177, a portion of the connection portion 140, and a portion of the region including the end portion are cut away.

[0318] [Display device 100B] The display device 100B shown in Figure 16 has, between a substrate 351 and a substrate 352, a transistor 201, a transistor 205, a light-emitting device 130R that emits red light, a light-emitting device 130G that emits green light, and a light-emitting device 130B that emits blue light, etc.

[0319] For details of the light emitting devices 130R, 130G, and 130B, refer to the first to third embodiments.

[0320] Light-emitting device 130R has conductive layer 224R, conductive layer 151R on conductive layer 224R, and conductive layer 152R on conductive layer 151R. Light-emitting device 130G has conductive layer 224G, conductive layer 151G on conductive layer 224G, and conductive layer 152G on conductive layer 151G. Light-emitting device 130B has conductive layer 224B, conductive layer 151B on conductive layer 224B, and conductive layer 152B on conductive layer 151B.

[0321] The conductive layer 224R is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214. An end of the conductive layer 151R is located outside an end of the conductive layer 224R. An insulating layer 156R is provided to have a region in contact with a side surface of the conductive layer 151R, and a conductive layer 152R is provided to cover the conductive layer 151R and the insulating layer 156R.

[0322] Conductive layer 224G, conductive layer 151G, conductive layer 152G, and insulating layer 156G in light-emitting device 130G, and conductive layer 224B, conductive layer 151B, conductive layer 152B, and insulating layer 156B in light-emitting device 130B are similar to conductive layer 224R, conductive layer 151R, conductive layer 152R, and insulating layer 156R in light-emitting device 130R, and therefore detailed description thereof will be omitted.

[0323] Recesses are formed in the conductive layers 224R, 224G, and 224B so as to cover the openings provided in the insulating layer 214. The layer 128 is embedded in the recesses.

[0324] The layer 128 has a function of planarizing the recesses of the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B. The conductive layer 151R, the conductive layer 151G, and the conductive layer 151B, which are electrically connected to the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B, are provided on the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B, and the layer 128. Therefore, the regions overlapping with the recesses of the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B can also be used as light-emitting regions, and the aperture ratio of the pixel can be increased.

[0325] The layer 128 may be an insulating layer or a conductive layer. For the layer 128, various inorganic insulating materials, organic insulating materials, and conductive materials can be appropriately used. In particular, the layer 128 is preferably formed using an insulating material, and more preferably formed using an organic insulating material. For example, the organic insulating material that can be used for the first insulating layer 127 described above can be used for the layer 128.

[0326] A protective layer 131 is provided on the light emitting device 130R, the light emitting device 130G, and the light emitting device 130B. The protective layer 131 and the substrate 352 are bonded via an adhesive layer 142. The substrate 352 is provided with a light shielding layer 157. A solid sealing structure, a hollow sealing structure, or the like can be applied to seal the light emitting device 130. In FIG. 16, the space between the substrate 352 and the substrate 351 is filled with the adhesive layer 142, and a solid sealing structure is applied. Alternatively, the space may be filled with an inert gas (nitrogen, argon, or the like), and a hollow sealing structure may be applied. In this case, the adhesive layer 142 may be provided so as not to overlap with the light emitting device. The space may also be filled with a resin different from the adhesive layer 142 provided in a frame shape.

[0327] 16 shows an example in which the connection portion 140 has a conductive layer 224C obtained by processing the same conductive film as the conductive layers 224R, 224G, and 224B, a conductive layer 151C obtained by processing the same conductive film as the conductive layers 151R, 151G, and 151B, and a conductive layer 152C obtained by processing the same conductive film as the conductive layers 152R, 152G, and 152B. Also, FIG. 16 shows an example in which an insulating layer 156C is provided so as to have an area overlapping with a side surface of the conductive layer 151C.

[0328] The display device 100B is a top emission type. Light emitted by the light emitting device is emitted to the substrate 352 side. The substrate 352 is preferably made of a material that is highly transparent to visible light. When the light emitting device emits infrared or near infrared light, it is preferably made of a material that is highly transparent to the infrared light. The pixel electrode contains a material that reflects visible light, and the counter electrode (common electrode 155) contains a material that transmits visible light.

[0329] An insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are provided over a substrate 351 in this order. A part of the insulating layer 211 functions as a gate insulating layer for each transistor. A part of the insulating layer 213 functions as a gate insulating layer for each transistor. The insulating layer 215 is provided to cover the transistors. The insulating layer 214 is provided to cover the transistors and functions as a planarizing layer. Note that the number of gate insulating layers and the number of insulating layers covering the transistors are not limited, and each may be a single layer or two or more layers.

[0330] Each of the insulating layers 211, 213, and 215 is preferably an inorganic insulating film.

[0331] The insulating layer 214, which functions as a planarizing layer, is preferably an organic insulating layer.

[0332] The transistor 201 and the transistor 205 each have a conductive layer 221 functioning as a gate, an insulating layer 211 functioning as a gate insulating layer, a conductive layer 222a and a conductive layer 222b functioning as a source and a drain, a semiconductor layer 231, an insulating layer 213 functioning as a gate insulating layer, and a conductive layer 223 functioning as a gate.

[0333] A connection portion 204 is provided in a region of the substrate 351 where the substrate 352 does not overlap. In the connection portion 204, a source electrode or a drain electrode of the transistor 201 is electrically connected to the FPC 353 through a conductive layer 166 and a connection layer 242. The conductive layer 166 is an example of a laminated structure of a conductive film obtained by processing the same conductive film as the conductive layers 224R, 224G, and 224B, a conductive film obtained by processing the same conductive film as the conductive layers 151R, 151G, and 151B, and a conductive film obtained by processing the same conductive film as the conductive layers 152R, 152G, and 152B. On the upper surface of the connection portion 204, the conductive layer 166 is exposed. This allows the connection portion 204 and the FPC 353 to be electrically connected through the connection layer 242.

[0334] It is preferable to provide a light-shielding layer 157 on the surface of the substrate 352 facing the substrate 351. The light-shielding layer 157 can be provided between adjacent light-emitting devices, on the connection portion 140, on the circuit 356, etc. In addition, various optical members can be disposed on the outside of the substrate 352.

[0335] The materials usable for the substrate 120 can be used for the substrate 351 and the substrate 352, respectively.

[0336] The adhesive layer 142 may be made of a material that can be used for the resin layer 122 .

[0337] The connection layer 242 may be an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like.

[0338] [Display device 100D] The display device 100D shown in FIG. 17 is a modification of the display device 100B shown in FIG. 16, and differs from the display device 100B mainly in that the display device 100D has colored layers 132R, 132G, and 132B.

[0339] In the display device 100D, the light-emitting device 130 has an area overlapping one of the colored layer 132R, the colored layer 132G, and the colored layer 132B. The colored layer 132R, the colored layer 132G, and the colored layer 132B can be provided on the surface of the substrate 352 facing the substrate 351. An end of the colored layer 132R, an end of the colored layer 132G, and an end of the colored layer 132B can overlap the light-shielding layer 157.

[0340] In the display device 100D, the light emitting device 130 can emit, for example, white light. For example, the colored layer 132R can transmit red light, the colored layer 132G can transmit green light, and the colored layer 132B can transmit blue light. The display device 100D may be configured such that the colored layers 132R, 132G, and 132B are provided between the protective layer 131 and the adhesive layer 142.

[0341] 16 and 17 and the like show an example in which the upper surface of the layer 128 has a flat portion, but the shape of the layer 128 is not particularly limited.

[0342] This embodiment mode can be combined with other embodiment modes or examples as appropriate. In addition, in the case where a plurality of configuration examples are shown in one embodiment mode in this specification, the configuration examples can be combined as appropriate.

[0343] (Embodiment 5) In this embodiment, an electronic device according to one embodiment of the present invention will be described.

[0344] The electronic devices of this embodiment include the display device of one embodiment of the present invention in a display portion. The display device of one embodiment of the present invention has high display performance and can easily achieve high definition and high resolution. Therefore, the display device of one embodiment of the present invention can be used in the display portion of various electronic devices.

[0345] Examples of electronic devices include electronic devices with relatively large screens, such as television devices, desktop or notebook personal computers, computer monitors, digital signage, large game machines such as pachinko machines, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and audio playback devices.

[0346] In particular, the display device of one embodiment of the present invention can be suitably used in electronic devices having a relatively small display area because it can increase the resolution. Examples of such electronic devices include wristwatch-type and bracelet-type information terminals (wearable devices), and head-mounted wearable devices such as VR devices, glasses-type AR devices, and MR devices.

[0347] The electronic device of this embodiment may have a sensor (including a function of measuring force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays).

[0348] An example of a wearable device that can be worn on the head will be described with reference to FIGS. 18(A) to 18(D).

[0349] Electronic device 700A shown in FIG. 18(A) and electronic device 700B shown in FIG. 18(B) each have a pair of display panels 751, a pair of housings 721, a communication unit (not shown), a pair of mounting units 723, a control unit (not shown), an imaging unit (not shown), a pair of optical members 753, a frame 757, and a pair of nose pads 758.

[0350] The display device of one embodiment of the present invention can be applied to the display panel 751. Thus, the electronic device can be highly reliable.

[0351] Each of the electronic device 700A and the electronic device 700B can project an image displayed on the display panel 751 onto a display area 756 of the optical member 753. Since the optical member 753 has translucency, a user can see the image displayed in the display area superimposed on a transmitted image visually recognized through the optical member 753.

[0352] The electronic device 700A and the electronic device 700B may be provided with a camera capable of capturing an image of the front as an imaging unit. In addition, the electronic device 700A and the electronic device 700B may each be provided with an acceleration sensor such as a gyro sensor, thereby detecting the orientation of the user's head and displaying an image corresponding to the orientation in the display area 756.

[0353] The communication unit has a wireless communication device and can supply, for example, a video signal through the wireless communication device. Note that instead of or in addition to the wireless communication device, a connector to which a cable through which a video signal and a power supply potential can be connected may be provided.

[0354] Furthermore, the electronic device 700A and the electronic device 700B are provided with a battery, which can be charged wirelessly and / or wired.

[0355] The housing 721 may be provided with a touch sensor module.

[0356] As the touch sensor module, various touch sensors can be applied. For example, various types of sensors can be adopted, such as a capacitance type, a resistive film type, an infrared type, an electromagnetic induction type, a surface acoustic wave type, or an optical type. In particular, it is preferable to apply a capacitance type or an optical type sensor to the touch sensor module.

[0357] Electronic device 800A shown in FIG. 18(C) and electronic device 800B shown in FIG. 18(D) each have a pair of display units 820, a housing 821, a communication unit 822, a pair of mounting units 823, a control unit 824, a pair of imaging units 825, and a pair of lenses 832.

[0358] The display device of one embodiment of the present invention can be applied to the display portion 820. Thus, the electronic device can be made highly reliable.

[0359] Display unit 820 is provided inside housing 821 at a position that can be viewed through lens 832. Also, by displaying different images on the pair of display units 820, it is possible to perform three-dimensional display using parallax.

[0360] It is preferable that electronic device 800A and electronic device 800B each have a mechanism capable of adjusting the left-right positions of lens 832 and display unit 820 so that they are optimally positioned according to the position of the user's eyes.

[0361] The mounting portion 823 allows the user to mount the electronic device 800A or the electronic device 800B on the head.

[0362] The imaging unit 825 has a function of acquiring external information. Data acquired by the imaging unit 825 can be output to the display unit 820. An image sensor can be used for the imaging unit 825. In addition, multiple cameras may be provided so as to be compatible with multiple angles of view, such as telephoto and wide angle.

[0363] The electronic device 800A may have a vibration mechanism that functions as a bone conduction earphone.

[0364] The electronic device 800A and the electronic device 800B may each have an input terminal. The input terminal can be connected to a cable for supplying a video signal from a video output device or the like and power for charging a battery provided in the electronic device.

[0365] The electronic device of one embodiment of the present invention may have a function of wireless communication with the earphone 750.

[0366] 18B includes an earphone unit 727. A part of a wiring connecting the earphone unit 727 and a control unit may be disposed inside the housing 721 or the attachment unit 723.

[0367] 18D includes an earphone unit 827. For example, the earphone unit 827 and the control unit 824 may be configured to be connected to each other by wire.

[0368] As described above, as electronic devices according to one embodiment of the present invention, both glasses-type devices (such as the electronic device 700A and the electronic device 700B) and goggles-type devices (such as the electronic device 800A and the electronic device 800B) are suitable.

[0369] An electronic device 6500 shown in FIG. 19A is a portable information terminal that can be used as a smartphone.

[0370] The electronic device 6500 includes a housing 6501, a display portion 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508. The display portion 6502 has a touch panel function.

[0371] The display device of one embodiment of the present invention can be applied to the display portion 6502. Therefore, the electronic device can be highly reliable.

[0372] FIG. 19B is a schematic cross-sectional view including the end portion of the housing 6501 on the microphone 6506 side.

[0373] A light-transmitting protective member 6510 is provided on the display surface side of the housing 6501, and a display panel 6511, optical members 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc. are arranged in the space surrounded by the housing 6501 and the protective member 6510.

[0374] A display panel 6511, an optical member 6512, and a touch sensor panel 6513 are fixed to the protective member 6510 by an adhesive layer (not shown).

[0375] In an area outside the display unit 6502, a part of the display panel 6511 is folded back, and the folded back part is connected to an FPC 6515. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on a printed circuit board 6517.

[0376] The display device of one embodiment of the present invention can be applied to the display panel 6511. Therefore, an extremely lightweight electronic device can be realized. In addition, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be mounted thereon while keeping the thickness of the electronic device small. In addition, by folding back a part of the display panel 6511 and arranging a connection portion with the FPC 6515 on the back side of the pixel portion, an electronic device with a narrow frame can be realized.

[0377] 19C shows an example of a television set. In a television set 7100, a display portion 7000 is incorporated in a housing 7171. Here, the housing 7171 is supported by a stand 7173.

[0378] The display device of one embodiment of the present invention can be applied to the display portion 7000. Therefore, the electronic device can be provided with high reliability.

[0379] A television set 7100 shown in FIG. 19C can be operated using an operation switch provided in a housing 7171 and a remote control 7151 provided separately.

[0380] 19D shows an example of a laptop personal computer 7200. The laptop personal computer 7200 includes a housing 7211, a keyboard 7212, a pointing device 7213, and an external connection port 7214. A display portion 7000 is incorporated in the housing 7211.

[0381] The display device of one embodiment of the present invention can be applied to the display portion 7000. Therefore, the electronic device can be provided with high reliability.

[0382] 19(E) and 19(F) show an example of digital signage.

[0383] 19E includes a housing 7301, a display portion 7000, and a speaker 7303. The digital signage 7300 may further include an LED lamp, an operation key (including a power switch or an operation switch), a connection terminal, various sensors, a microphone, and the like.

[0384] 19(F) shows a digital signage 7400 attached to a cylindrical pillar 7401. The digital signage 7400 has a display unit 7000 provided along the curved surface of the pillar 7401.

[0385] 19E and 19F, the display device of one embodiment of the present invention can be applied to the display portion 7000. Therefore, the electronic device can have high reliability.

[0386] The larger the display unit 7000, the more information can be provided at one time. Also, the larger the display unit 7000, the more easily it catches people's attention, which can increase the advertising effect of, for example, advertisements.

[0387] Furthermore, as shown in FIGS. 19(E) and 19(F), it is preferable that the digital signage 7300 or the digital signage 7400 be capable of linking with an information terminal 7311 or an information terminal 7411 such as a smartphone carried by a user via wireless communication.

[0388] The electronic devices shown in Figures 20(A) to 20(G) have a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), a connection terminal 9006, a sensor 9007 (including a function of measuring force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared rays), a microphone 9008, etc.

[0389] 20(A) to 20(G) have various functions, such as a function of displaying various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function of displaying a calendar, date, time, etc., a function of controlling processing by various software (programs), a wireless communication function, a function of reading and processing a program or data recorded in a recording medium, etc.

[0390] The electronic devices shown in FIGS. 20A to 20G will be described in detail below.

[0391] FIG. 20A is a perspective view showing a mobile information terminal 9171. The mobile information terminal 9171 can be used as, for example, a smartphone. Note that the mobile information terminal 9171 may be provided with a speaker 9003, a connection terminal 9006, a sensor 9007, or the like. The mobile information terminal 9171 can display text and image information on a plurality of surfaces thereof. FIG. 20A shows an example in which three icons 9050 are displayed. Information 9051 shown in a dashed rectangle can also be displayed on another surface of the display unit 9001. Examples of the information 9051 include notification of incoming e-mail, SNS, phone call, etc., the title of the e-mail or SNS, the sender's name, the date and time, the remaining battery level, radio wave intensity, and the like. Alternatively, the icon 9050, etc. may be displayed at the position where the information 9051 is displayed.

[0392] 20B is a perspective view of a mobile information terminal 9172. The mobile information terminal 9172 has a function of displaying information on three or more surfaces of the display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different surfaces. For example, a user can check information 9053 displayed in a position that can be observed from above the mobile information terminal 9172 while the mobile information terminal 9172 is stored in a breast pocket of a garment.

[0393] 20C is a perspective view of a tablet terminal 9173. The tablet terminal 9173 is capable of executing various applications such as mobile phone, e-mail, text browsing and creation, music playback, Internet communication, computer games, etc. The tablet terminal 9173 has a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front side of a housing 9000, operation keys 9005 as operation buttons on the left side of the housing 9000, and a connection terminal 9006 on the bottom.

[0394] 20D is a perspective view showing a wristwatch-type mobile information terminal 9200. The mobile information terminal 9200 can be used as, for example, a smart watch (registered trademark). The display surface of the display unit 9001 is curved, and display can be performed along the curved display surface. The mobile information terminal 9200 can also perform hands-free conversation by communicating with, for example, a headset capable of wireless communication. The mobile information terminal 9200 can also perform data transmission and charging with another information terminal through a connection terminal 9006. Note that charging may be performed by wireless power supply.

[0395] 20(E) to 20(G) are perspective views showing a foldable mobile information terminal 9201. FIG. 20(E) is a perspective view of the mobile information terminal 9201 in an unfolded state, FIG. 20(G) is a perspective view of the mobile information terminal 9201 in a folded state, and FIG. 20(F) is a perspective view of a state in the middle of changing from one of FIG. 20(E) and FIG. 20(G) to the other. The mobile information terminal 9201 has excellent portability in a folded state, and has excellent viewability of the display due to a seamless wide display area in an unfolded state. A display portion 9001 of the mobile information terminal 9201 is supported by three housings 9000 connected by a hinge 9055. For example, the display portion 9001 can be bent with a curvature radius of 0.1 mm or more and 150 mm or less.

[0396] This embodiment mode can be combined with other embodiment modes or examples as appropriate. In addition, in the case where a plurality of configuration examples are shown in one embodiment mode in this specification, the configuration examples can be combined as appropriate.

[0397] At least a part of the configuration examples illustrated in this embodiment and the drawings corresponding thereto can be appropriately combined with other configuration examples or drawings.

[0398] This embodiment mode can be implemented by appropriately combining at least a part of it with other embodiment modes described in this specification. EXAMPLES

[0399] In this example, in order to explain a display device according to one embodiment of the present invention, light-emitting devices 1A and 1B, which are red light-emitting devices with different cathode thicknesses, and light-emitting devices 2A and 2B, which are blue light-emitting devices with different cathode thicknesses, are fabricated, and the results of comparing the light-emitting efficiency are described. In addition, light-emitting devices 3R (red), 3G (green), and 3B (blue), which are light-emitting devices fabricated by forming an organic compound layer by photolithography so as to have a resolution of 3207 ppi, are fabricated, and the results of evaluating the characteristics are described.

[0400] First, a method for producing light emitting device 1A, light emitting device 1B, light emitting device 2A, and light emitting device 2B will be described. The structural formulas of the organic compounds used in each light emitting device are shown below.

[0401] [ka]

[0402] (Method of Manufacturing Light-Emitting Device 1A) On a glass substrate, 50 nm of titanium (Ti), 70 nm of aluminum (Al), and 2 nm of Ti were laminated from the substrate side, and then baked at 300°C for 1 hour in air. After that, 10 nm of indium tin oxide containing silicon oxide (ITSO) was laminated by sputtering to form an anode as a transparent electrode. The electrode area was 4 mm2. 2 (2mm x 2mm).

[0403] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water and baked at 200° C. for 1 hour.

[0404] Then 1×10 -4 The substrate was introduced into a vacuum deposition apparatus whose inside had been reduced in pressure to about Pa, and heat treatment was carried out at 170° C. for 30 minutes in a heating chamber in the vacuum deposition apparatus, and then the substrate was allowed to cool for about 30 minutes.

[0405] Next, the substrate was fixed to a holder installed in a vacuum deposition apparatus so that the surface on which the anode was formed faced downward, and a hole injection layer was formed on the anode by co-depositing 10 nm of N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF) and an electron acceptor material (OCHD-003) with a molecular weight of 672 and containing 4 or more fluorines by a vapor deposition method at a weight ratio of 1:0.03 (= PCBBiF:OCHD-003).

[0406] On the hole injection layer, PCBBiF was evaporated to a thickness of 30 nm to form a hole transport layer.

[0407] Next, on the hole-transporting layer, 11-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]phenanthro[9',10':4,5]furo[2,3-b]pyrazine (abbreviation: 11mDBtBPPnfpr), PCBBiF, and a red phosphorescent dopant (OCPG-006) were co-deposited to a thickness of 40 nm in a weight ratio of 0.7:0.3:0.05 (=11mDBtBPPnfpr:PCBBiF:OCPG-006) to form an emitting layer.

[0408] Next, 2-[4-(2-naphthalenyl)phenyl]-4-phenyl-6-spiro[9H-fluorene-9,9'-[9H]xanthene]-4-yl-1,3,5-triazine (abbreviation: βNP-SFx(4)Tzn) was evaporated to a thickness of 20 nm, and then 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P) was evaporated to a thickness of 20 nm to form an electron transport layer.

[0409] After the formation of the electron transport layer, lithium fluoride and ytterbium were co-deposited to a thickness of 1.5 nm so as to give a volume ratio of 1:0.5 (=LiF:Yb) to form an electron injection layer.

[0410] On the electron injection layer, a cathode was formed by co-evaporation of silver (Ag) and magnesium (Mg) at a volume ratio of 1:0.1 and a thickness of 15 nm, to prepare a light-emitting device 1A.

[0411] The cathode is a semi-transparent and semi-reflective electrode that has the functions of reflecting and transmitting light, and the light-emitting device of this example is a top-emission type that extracts light from the cathode side, and is a single-type light-emitting device. In addition, PCBBiF is evaporated to a thickness of 80 nm on the cathode as a cap layer to improve the light extraction efficiency.

[0412] (Method of Fabricating Light-Emitting Device 1B) Light-emitting device 1B is a red light-emitting device with a different cathode thickness from light-emitting device 1A. That is, light-emitting device 1B had a cathode formed on the electron injection layer by co-evaporating silver (Ag) and magnesium (Mg) in a volume ratio of 1:0.1 and a thickness of 25 nm. The rest of the device was fabricated in the same manner as light-emitting device 1A.

[0413] (Method of Fabricating Light-Emitting Device 2A) Light-emitting device 2A is a blue light-emitting device that differs from light-emitting device 1A in the configuration of the hole transport layer, the configuration of the light-emitting layer, and the thickness of the electron transport layer. The hole transport layer was formed by evaporating 105 nm of PCBBiF on the hole injection layer, and then evaporating 10 nm of N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP). The light-emitting layer was formed on the hole-transporting layer by co-evaporating 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth) and 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b′]bisbenzofuran (abbreviation: 3,10PCA2Nbf(IV)-02) to a thickness of 25 nm at a weight ratio of 1:0.015 (=αN-βNPAnth:3,10PCA2Nbf(IV)-02). The electron-transporting layer was formed by evaporating βNP-SFx(4)Tzn to a thickness of 20 nm, followed by evaporating mPPhen2P to a thickness of 15 nm.

[0414] (Method of Manufacturing Light-Emitting Device 2B) Light-emitting device 2B is a blue light-emitting device with a different cathode thickness from light-emitting device 2A. That is, light-emitting device 2B had a cathode formed on the electron injection layer by co-evaporating silver (Ag) and magnesium (Mg) in a volume ratio of 1:0.1 and a thickness of 25 nm. The rest of the device was fabricated in the same manner as light-emitting device 2A.

[0415] The device structures of light-emitting device 1A and light-emitting device 1B are summarized in Table 1.

[0416] [Table 1]

[0417] The device structures of light-emitting device 2A and light-emitting device 2B are summarized in Table 2.

[0418] [Table 2]

[0419] Next, a method for producing light-emitting device 3R, light-emitting device 3G, and light-emitting device 3B, which are light-emitting devices produced by forming an organic compound layer using a photolithography method so that the resolution is 3207 ppi, will be described. Note that light-emitting device 3R has an organic compound layer with the same configuration and a cathode with the same thickness as light-emitting device 1A described above, except that the thickness of the hole transport layer is different. Also, light-emitting device 3B has an organic compound layer with the same configuration and a cathode with the same thickness as light-emitting device 2A described above, except that the thickness of the hole transport layer is different. The structural formulas of the organic compounds used in each light-emitting device are shown below.

[0420] [ka]

[0421] (Method of Manufacturing Light-Emitting Device 3R, Light-Emitting Device 3G, and Light-Emitting Device 3B) First, 50 nm of titanium (Ti), 70 nm of aluminum (Al), and 2 nm of Ti were laminated on a silicon substrate with wiring, starting from the substrate side, and then baked at 300°C for 1 hour in air. After that, 10 nm of indium tin oxide containing silicon oxide (ITSO) was laminated by sputtering, and then processed to a resolution of 3207 ppi using photolithography to form an anode. After that, a film of SiON was formed, and side walls were formed with SiON so that the ends of the anode were covered. The anode was formed so that a total of 63,001 pixels, 251 x 251, were arranged in a matrix within an area of ​​2 mm x 2 mm. This shape and arrangement correspond to 3207 ppi.

[0422] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate was heat-treated at 120°C for 120 seconds, and then 1,1,1,3,3,3-hexamethyldisilazane (abbreviation: HMDS) was vaporized and sprayed onto the substrate heated to 60°C for 120 seconds. This makes it possible to make the laminated film formed on the anode less likely to peel off from the anode during the fabrication process.

[0423] Then 1×10 -4 The substrate was introduced into a vacuum deposition apparatus whose inside had been reduced in pressure to about Pa, and vacuum baking was carried out at 170° C. for 60 minutes in a heating chamber in the vacuum deposition apparatus, and then the substrate was allowed to cool for about 60 minutes.

[0424] Next, a hole injection layer was formed in the same manner as in the fabrication of light-emitting device 1A.

[0425] On the hole injection layer, PCBBiF was deposited to a thickness of 103.5 nm, and then DBfBB1TP was deposited to a thickness of 10 nm to form a hole transport layer.

[0426] Next, in the same manner as in the fabrication of light-emitting device 2A, which is a blue light-emitting device, a light-emitting layer and an electron transport layer were formed, and then the organic compound layer was processed by photolithography in the manner described below.

[0427] <<Processing method using photolithography>> The substrate on which the electron transport layer had been formed was removed from the vacuum deposition apparatus and exposed to the atmosphere. Then, using trimethylaluminum (TMA) as a precursor and water vapor as an oxidizing agent, an aluminum oxide film was formed by the ALD method to a thickness of 30 nm to form the first sacrificial layer.

[0428] Next, a tungsten (W) film was formed on the first sacrificial layer by sputtering to a thickness of 54 nm, to form a second sacrificial layer.

[0429] A photoresist was applied onto the second sacrificial layer, and the photoresist was exposed and developed to process the second sacrificial layer so that its edge was positioned inside the edge of the anode. This allows the organic compound layer to be processed into a shape that has an edge inside the edge of the anode.

[0430] Using the photoresist as a mask, the second sacrificial layer was processed using an etching gas containing SF6, and using the second sacrificial layer as a hard mask, the first sacrificial layer was processed using an etching gas containing fluoroform (CHF3), helium (He), and methane (CH4) with a flow rate ratio of CHF3:He:CH4 = 16.5:118.5:15. After this, the organic compound layer was processed using an etching gas containing oxygen (O2).

[0431] The above is the processing method using the photolithography method. By performing processing using the photolithography method, the hole injection layer, the hole transport layer, the light emitting layer, and the electron transport layer of the light emitting device 3B were formed. In addition, the anodes of the parts where the light emitting device 3R and the light emitting device 3G were to be formed were exposed.

[0432] On the second sacrificial layer and the anode, PCBBiF and OCHD-003 were co-deposited by evaporation to a thickness of 10 nm at a weight ratio of 1:0.1 (=PCBBiF:OCHD-003) to form a hole injection layer.

[0433] On the hole injection layer, PCBBiF was evaporated to a thickness of 157.5 nm to form a hole transport layer.

[0434] Then, 8-(1,1':4',1''-terphenyl-3-yl-2,4,5,6,2',3',5',6',2'',3'',4'',5'',6''-d 13 )-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm-d 13 ), 9-(2-naphthyl)-9′-phenyl-9H,9′H-3,3′-bicarbazole (abbreviation: βNCCP), and a green phosphorescent dopant, tris{2-[5-(methyl-d3)-4-phenyl-2-pyridinyl-κN]phenyl-κC}iridium(III) (abbreviation: Ir(5m4dppy-d3)3), were mixed in a weight ratio of 0.5:0.5:0.1 (=8mpTP-4mDBtPBfpm-d 13 The light-emitting layer was formed to a thickness of 40 nm by co-evaporation of:βNCCP:Ir(5m4dppy-d3)3).

[0435] Next, βNP-SFx(4)Tzn was evaporated to a thickness of 10 nm, and then mPPhen2P was evaporated to a thickness of 15 nm to form an electron transport layer. Thereafter, the hole injection layer, hole transport layer, light emitting layer, and electron transport layer of the light emitting device 3G were formed in the same manner as in the processing method using the photolithography method described above. In addition, the anode of the portion forming the light emitting device 3R was exposed.

[0436] Next, PCBBiF and OCHD-003 were co-deposited on the second sacrificial layer and the anode by a vapor deposition method to a thickness of 10 nm in a weight ratio of 1:0.1 (=PCBBiF:OCHD-003) to form a hole injection layer.

[0437] On the hole injection layer, PCBBiF was evaporated to a thickness of 200 nm to form a hole transport layer.

[0438] Next, an emitting layer and an electron transport layer were formed in the same manner as in the fabrication method of light-emitting device 1A, which is a red light-emitting device, and then a hole injection layer, a hole transport layer, an emitting layer and an electron transport layer of light-emitting device 3R were formed in the same manner as in the processing method using the photolithography method described above.

[0439] After forming the hole injection layer, hole transport layer, light emitting layer, and electron transport layer of the light emitting device 3R, the second sacrificial layer was removed using an etching gas containing SF6, leaving the first sacrificial layer. Then, an aluminum oxide film was formed by the ALD method to a thickness of 15 nm to form a protective film.

[0440] Next, a photosensitive polymer material was formed on the protective film using photolithography, without overlapping with the anode. After that, it was heated at 100°C in an air atmosphere for 1 hour, and then unnecessary parts of the first sacrificial layer and protective film were removed using a mixed acid solution containing hydrofluoric acid (HF) to expose the second electron transport layer. At this time, the photosensitive polymer material functions as a resist.

[0441] The substrate with the second electron transport layer exposed was then immersed in 1×10 -4 The mixture was introduced into a vacuum deposition apparatus whose inside had been reduced in pressure to about Pa, and vacuum baking was carried out at 100° C. for 90 minutes in a heating chamber in the vacuum deposition apparatus.

[0442] Next, lithium fluoride and ytterbium were co-deposited at a volume ratio of 1:0.5 (=LiF:Yb) to form an electron injection layer of 1.5 nm, and then silver (Ag) and magnesium (Mg) were co-deposited at a volume ratio of 1:0.1 and a film thickness of 15 nm to form a cathode, thereby producing light-emitting device 3R, light-emitting device 3G, and light-emitting device 3B. In addition, a 70-nm ITO (indium oxide-tin oxide) film was formed as a cap layer on the cathode of each light-emitting device by sputtering.

[0443] Table 3 shows the device structures of light-emitting device 3R, light-emitting device 3G, and light-emitting device 3B.

[0444] [Table 3]

[0445] Each of the light-emitting devices thus fabricated was placed in a glove box with a nitrogen atmosphere and sealed with a glass substrate to prevent the light-emitting device from being exposed to the atmosphere (a UV-curable sealant was applied around the element, UV was irradiated only onto the sealant without irradiating the light onto the light-emitting device, and heat-treated at 80°C for 1 hour under atmospheric pressure). The initial characteristics of each light-emitting device were then measured.

[0446] The current efficiency-luminance characteristics of the light-emitting device 1A and the light-emitting device 1B are shown in Fig. 21. Furthermore, the blue index-luminance characteristics of the light-emitting device 2A and the light-emitting device 2B are shown in Fig. 22.

[0447] The blue index (BI) is a value obtained by further dividing the current efficiency (cd / A) by the chromaticity y, and is one of the indices that express the luminous properties of blue light emission. The smaller the chromaticity y, the higher the color purity of the blue light emission tends to be. Blue light emission with high color purity can express a wide range of blue even with a small luminance component, and the use of blue light emission with high color purity reduces the required luminance to express blue, thereby reducing power consumption. Therefore, the BI, which takes into account the chromaticity y, which is one of the indices of blue purity, is preferably used as a means of expressing the efficiency of blue light emission, and it can be said that the higher the BI of a light-emitting device, the better its efficiency as a blue light-emitting device used in a display.

[0448] The luminance of the light-emitting device 1A and the light-emitting device 1B is 1000 cd / m 2 The main characteristics of the light-emitting device 2A and the light-emitting device 2B in the vicinity of 1000 cd / m are shown in Table 4. 2 The main characteristics in the vicinity are shown in Table 5. The luminance, CIE chromaticity, and electroluminescence spectrum were measured using a spectroradiometer (SR-UL1R, manufactured by Topcon Corporation) at room temperature.

[0449] [Table 4]

[0450] [Table 5]

[0451] 21 and Table 4, the current efficiency of light-emitting device 1B was higher than that of light-emitting device 1A. This shows that in a red light-emitting device, a cathode film thickness of 25 nm increases the luminous efficiency.

[0452] 22 and Table 5, the blue index of light-emitting device 2A was higher than the blue index of light-emitting device 2B. This shows that in a blue light-emitting device, a cathode film thickness of 15 nm increases the luminous efficiency.

[0453] As explained in the first embodiment with reference to Fig. 2(B), since the Ag:Mg film has a low absorptance for red light, it can be said that in a red light-emitting device, the thicker the cathode film, the higher the current efficiency, since the microcavity structure improves the directivity of light in the direction perpendicular to the light-emitting surface. On the other hand, since the Ag:Mg film has a high absorptance for blue light, it can be said that in a blue light-emitting device, the thinner the cathode film, the more suppressed the light absorption by the cathode, and the higher the current efficiency.

[0454] From the above results, it was found that, in the display device of one embodiment of the present invention, by making the thickness of the auxiliary electrode 106 different for each light-emitting device that emits different light, more specifically, by making the thickness of the auxiliary electrode 106R of the red light-emitting device 130R thicker than the thickness of the auxiliary electrode 106B of the blue light-emitting device 130B, as shown in FIG. 1B, the cathode thickness can be made different for each light-emitting device, and the light-emitting efficiency of each light-emitting device can be improved. In addition, in the display device of one embodiment of the present invention, by providing the auxiliary electrode 106R in the red light-emitting device 130R and not providing the auxiliary electrode in the blue light-emitting device 130B, as shown in FIG. 3B, it was found that the cathode thickness can be made different for each light-emitting device, and the light-emitting efficiency of each light-emitting device can be improved.

[0455] Next, the current density-voltage characteristics of the light-emitting device 3R (number of samples n=3) are shown in Fig. 23, the current efficiency-current density characteristics are shown in Fig. 24, the external quantum efficiency-current density characteristics are shown in Fig. 25, and the electroluminescence spectrum is shown in Fig. 26. Moreover, the current density-voltage characteristics of the light-emitting device 3G (number of samples n=3) are shown in Fig. 27, the current efficiency-current density characteristics are shown in Fig. 28, the external quantum efficiency-current density characteristics are shown in Fig. 29, and the electroluminescence spectrum is shown in Fig. 30. Moreover, the current density-voltage characteristics of the light-emitting device 3B (number of samples n=3) are shown in Fig. 31, the blue index-current density characteristics are shown in Fig. 32, the external quantum efficiency-current density characteristics are shown in Fig. 33, and the electroluminescence spectrum is shown in Fig. 34.

[0456] 23 to 26 also show the measurement results of a comparative light-emitting device (represented as Ref. in the figures) that has the same configuration as the light-emitting device 3R and was fabricated without going through the process of forming an organic compound layer by using a photolithography method. Also, FIGS. 27 to 30 also show the measurement results of a comparative light-emitting device (represented as Ref. in the figures) that has the same configuration as the light-emitting device 3G and was fabricated without going through the process of forming an organic compound layer by using a photolithography method. Also, FIGS. 31 to 34 also show the measurement results of a comparative light-emitting device (represented as Ref. in the figures) that has the same configuration as the light-emitting device 3B and was fabricated without going through the process of forming an organic compound layer by using a photolithography method. The cap layer of each comparative light-emitting device was formed by evaporating PCBBiF to a thickness of 80 nm.

[0457] From the above results, it was found that a light-emitting device with good characteristics could be fabricated with only a small deterioration in characteristics due to the process of forming an organic compound layer using photolithography.

[0458] In addition, each light-emitting device is supplied with 50mA / cm 2 The light-emitting device 3B was driven at a constant current density of 239 hours.

[0459] As described above, the light-emitting device 3R has an organic compound layer with the same configuration as the light-emitting device 1A described above and a cathode with the same thickness (15 nm) except for the thickness of the hole transport layer. As shown in Fig. 21, the light-emitting device 1A, which has a cathode thickness of 15 nm, had a lower current efficiency than the light-emitting device 1B, which has a cathode thickness of 25 nm. Therefore, in the configuration of the light-emitting device 3R, by providing an auxiliary electrode between the electron injection layer and the cathode and fabricating the cathode thickness to be 25 nm, it is expected that the light-emitting efficiency will be improved.

[0460] Moreover, the light-emitting device 3B has an organic compound layer with the same configuration as the light-emitting device 2A described above, and a cathode with the same thickness (15 nm), except for the thickness of the hole transport layer. As shown in Fig. 22, the light-emitting device 2A, which has a cathode thickness of 15 nm, has a higher blue index than the light-emitting device 2B, which has a cathode thickness of 25 nm. Therefore, it is expected that it is preferable not to provide an auxiliary electrode in the light-emitting device 3B, since it is possible to maintain high luminous efficiency. EXAMPLES

[0461] In this example, in order to explain a display device according to one embodiment of the present invention, light-emitting devices 4A and 4B, which are tandem red light-emitting devices each having a different cathode thickness, light-emitting devices 5A and 5B, which are tandem green light-emitting devices each having a different cathode thickness, and light-emitting devices 6A and 6B, which are tandem blue light-emitting devices each having a different cathode thickness, are manufactured, and the results of comparing the light-emitting efficiency are described. In addition, light-emitting devices 7R (red), 7G (green), and 7B (blue), which are tandem light-emitting devices manufactured by forming organic compound layers using a photolithography method so that the resolution is 3207 ppi, are manufactured, and the results of evaluating the characteristics are described.

[0462] First, there will be described methods for fabricating light-emitting devices 4A, 4B, 5A, 5B, 6A, and 6B. The structural formulas of the organic compounds used in each of the light-emitting devices are shown below.

[0463] [ka]

[0464] [ka]

[0465] (Method of Fabricating Light-Emitting Device 4A) On a glass substrate, 50 nm of titanium (Ti), 70 nm of aluminum (Al), and 2 nm of Ti were laminated from the substrate side, and then baked at 300°C for 1 hour in air. After that, 10 nm of indium tin oxide containing silicon oxide (ITSO) was laminated by sputtering to form an anode as a transparent electrode. The electrode area was 4 mm2. 2 (2mm x 2mm).

[0466] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water and baked at 200° C. for 1 hour.

[0467] Then 1×10 -4 The substrate was introduced into a vacuum deposition apparatus whose inside had been reduced in pressure to about Pa, and heat treatment was carried out at 170° C. for 30 minutes in a heating chamber in the vacuum deposition apparatus, and then the substrate was allowed to cool for about 30 minutes.

[0468] Next, the substrate was fixed to a holder installed in a vacuum deposition apparatus so that the surface on which the anode was formed faced downward, and PCBBiF and OCHD-003 were co-deposited onto the anode by deposition to a thickness of 10 nm in a weight ratio of 1:0.03 (=PCBBiF:OCHD-003) to form a hole injection layer.

[0469] On the hole injection layer, PCBBiF was evaporated to a thickness of 57.5 nm to form a first hole transport layer.

[0470] Next, a first light-emitting layer was formed on the first hole-transporting layer by co-evaporating 11mDBtBPPnfpr, PCBBiF, and a red phosphorescent dopant (OCPG-006) to a thickness of 40 nm in a weight ratio of 0.7:0.3:0.05 (=11mDBtBPPnfpr:PCBBiF:OCPG-006).

[0471] Next, 3,6-bis(diphenylamino)-9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9H-carbazole (abbreviation: DACT-II) was evaporated to a thickness of 10 nm to form a first electron transport layer.

[0472] After the formation of the first electron transport layer, 11mDBtBPPnfpr and 1-(2',7'-di-tert-butyl-9,9'-spirobi[9H-fluoren]-2-yl)-1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (abbreviation: 2',7'tBu-2hppSF) were co-evaporated to a thickness of 5 nm in a weight ratio of 1:1 (=11mDBtBPPnfpr:2',7'tBu-2hppSF) to form the first intermediate layer.

[0473] Next, a film of zinc phthalocyanine (abbreviation: ZnPc) was formed to a thickness of 2 nm to form a third intermediate layer.

[0474] Furthermore, PCBBiF and OCHD-003 were co-deposited to a thickness of 10 nm at a weight ratio of 1:0.15 (=PCBBiF:OCHD-003) to form a second intermediate layer.

[0475] Next, PCBBiF was evaporated onto the intermediate layer to a thickness of 65 nm to form a second hole transport layer.

[0476] A second light-emitting layer was formed on the second hole-transporting layer in the same manner as the first light-emitting layer.

[0477] Thereafter, 2mPCCzPDBq was evaporated to a thickness of 20 nm, and mPPhen2P was evaporated to a thickness of 25 nm to form a second electron transport layer.

[0478] After the formation of the second electron transport layer, lithium fluoride and ytterbium were co-deposited to a thickness of 1.5 nm so as to give a volume ratio of 1:0.5 (=LiF:Yb) to form an electron injection layer.

[0479] On the electron injection layer, a cathode was formed by co-evaporation of silver (Ag) and magnesium (Mg) at a volume ratio of 1:0.1 and a thickness of 15 nm, to prepare a light-emitting device 4A.

[0480] The cathode is a semi-transparent and semi-reflective electrode that has the functions of reflecting and transmitting light, and the light-emitting device of this embodiment is a top-emission type that extracts light from the cathode side, and is a tandem-type light-emitting device. In addition, ITO is evaporated to a thickness of 70 nm on the cathode as a cap layer to improve the light extraction efficiency.

[0481] (Method of Fabricating Light-Emitting Device 4B) Light-emitting device 4B is a red light-emitting device with a cathode film thickness different from that of light-emitting device 4A. That is, light-emitting device 4B had a cathode formed on the electron injection layer by co-evaporating silver (Ag) and magnesium (Mg) in a volume ratio of 1:0.1 and a film thickness of 25 nm. The rest of the device was fabricated in the same manner as light-emitting device 4A.

[0482] (Method of Fabricating Light-Emitting Device 5A) The light-emitting device 5A is a green light-emitting device that is different from the light-emitting device 4A in the thickness of the first and second hole transport layers, the configuration of the first and second light-emitting layers, and the thickness of the second electron transport layer. The first hole transport layer was formed by evaporating PCBBiF to a thickness of 32.5 nm on the hole injection layer. The first and second light-emitting layers were ... [2-(5-d3-methyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) (abbreviation: Ir(5mppy-d3)2(mbfpypy-d3)) was co-evaporated to a thickness of 40 nm so that the weight ratio was 0.6:0.4:0.1 (=8mpTP-4mDBtPBfpm:βNCCP:Ir(5mppy-d3)2(mbfpypy-d3)). The second hole transport layer was formed by evaporating PCBBiF to a thickness of 55 nm on the intermediate layer. The second electron transport layer was formed by evaporating 2mPCCzPDBq to a thickness of 10 nm, followed by evaporating mPPhen2P to a thickness of 15 nm.

[0483] (Method of Manufacturing Light-Emitting Device 5B) Light-emitting device 5B is a green light-emitting device having a different cathode thickness from light-emitting device 5A. That is, light-emitting device 5B has a cathode formed on the electron injection layer by co-evaporating silver (Ag) and magnesium (Mg) in a volume ratio of 1:0.1 and a thickness of 25 nm. The rest of the device was fabricated in the same manner as light-emitting device 5A.

[0484] (Method of Fabricating Light-Emitting Device 6A) The light-emitting device 6A is a blue light-emitting device having a different configuration of the first and second hole transport layers, the configuration of the first and second light-emitting layers, and the thickness of the second electron transport layer from the light-emitting device 4A. The first hole transport layer was formed by evaporating PCBBiF to a thickness of 10 nm on the hole injection layer, and then evaporating DBfBB1TP to a thickness of 10 nm. The first and second light-emitting layers were formed by co-evaporating αN-βNPAnth and 3,10PCA2Nbf(IV)-02 to a thickness of 25 nm so that the weight ratio was 1:0.015 (=αN-βNPAnth:3,10PCA2Nbf(IV)-02). The second hole transport layer was formed by evaporating PCBBiF to a thickness of 30 nm on the intermediate layer, and then evaporating DBfBB1TP to a thickness of 10 nm. The second electron transport layer was formed by depositing 2mPCCzPDBq to a thickness of 10 nm, and then depositing mPPhen2P to a thickness of 15 nm.

[0485] (Method of Manufacturing Light-Emitting Device 6B) Light-emitting device 6B is a blue light-emitting device with a different cathode thickness from light-emitting device 6A. That is, light-emitting device 6B has a cathode formed on the electron injection layer by co-evaporating silver (Ag) and magnesium (Mg) in a volume ratio of 1:0.1 to a thickness of 25 nm. The rest of the device was fabricated in the same manner as light-emitting device 6A.

[0486] Table 6 summarizes the device structures of light-emitting device 4A and light-emitting device 4B.

[0487] [Table 6]

[0488] The device structures of light-emitting device 5A and light-emitting device 5B are summarized in Table 7.

[0489] [Table 7]

[0490] The device structures of light-emitting device 6A and light-emitting device 6B are summarized in Table 8.

[0491] [Table 8]

[0492] Next, a method for producing light-emitting device 7R, light-emitting device 7G, and light-emitting device 7B, which are light-emitting devices produced by forming an organic compound layer using a photolithography method so that the resolution is 3207 ppi, will be described. The light-emitting device 7R has an organic compound layer with the same configuration and a cathode with the same thickness as the above-mentioned light-emitting device 4A, except that the configurations of the intermediate layer and the first electron transport layer are different. The organic compound layer of the light-emitting device 7G has a different configuration from the organic compound layer of the light-emitting device 5A, but is a green light-emitting device like the light-emitting device 5A and has a cathode with the same thickness. The light-emitting device 7B has an organic compound layer with the same configuration and a cathode with the same thickness as the above-mentioned light-emitting device 6A, except that the configuration of the intermediate layer is different, the thickness of the first hole transport layer is different, and the configuration of the first electron transport layer is different. The structural formulas of the organic compounds used in each light-emitting device are shown below.

[0493] [ka]

[0494] (Method of Manufacturing Light-Emitting Device 7R, Light-Emitting Device 7G, and Light-Emitting Device 7B) First, 50 nm of titanium (Ti), 70 nm of aluminum (Al), and 2 nm of Ti were laminated on a silicon substrate with wiring, starting from the substrate side, and then baked at 300°C for 1 hour in air. After that, 10 nm of indium tin oxide containing silicon oxide (ITSO) was laminated by sputtering, and then processed to a resolution of 3207 ppi using photolithography to form an anode. After that, a film of SiON was formed, and side walls were formed with SiON so that the ends of the anode were covered. The anode was formed so that a total of 63,001 pixels, 251 x 251, were arranged in a matrix within an area of ​​2 mm x 2 mm. This shape and arrangement correspond to 3207 ppi.

[0495] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate was heat-treated at 120°C for 120 seconds, and then 1,1,1,3,3,3-hexamethyldisilazane (abbreviation: HMDS) was vaporized and sprayed onto the substrate heated to 60°C for 120 seconds. This makes it possible to make the laminated film formed on the anode less likely to peel off from the anode during the fabrication process.

[0496] Then 1×10 -4 The substrate was introduced into a vacuum deposition apparatus whose inside had been reduced in pressure to about Pa, and vacuum baking was carried out at 170° C. for 60 minutes in a heating chamber in the vacuum deposition apparatus, and then the substrate was allowed to cool for about 60 minutes.

[0497] Next, a hole injection layer was formed in the same manner as in the fabrication of light-emitting device 4A.

[0498] On the hole injection layer, PCBBiF was deposited to a thickness of 20 nm, and then DBfBB1TP was deposited to a thickness of 10 nm to form a first hole transport layer.

[0499] Next, a first light-emitting layer was formed in the same manner as in the fabrication of light-emitting device 6A, which is a blue light-emitting device, and then 2mPCCzPDBq was evaporated to a thickness of 10 nm to form a first electron-transporting layer.

[0500] After forming the first electron transport layer, mPPhen2P and Li2O were co-evaporated to a thickness of 5 nm so as to have a volume ratio of 1:0.01 (=mPPhen2P:Li2O) to form a first intermediate layer, and then the third and second intermediate layers were formed in the same manner as in the fabrication method of light-emitting device 4A.

[0501] Next, in the same manner as in the fabrication method of the light-emitting device 6A, a second hole transport layer, a second light-emitting layer, and a second electron transport layer were formed, and then the organic compound layer was processed using a photolithography method as described below.

[0502] <<Processing method using photolithography>> The substrate on which the second electron transport layer had been formed was removed from the vacuum deposition apparatus and exposed to the atmosphere. Then, using trimethylaluminum (TMA) as a precursor and water vapor as an oxidizing agent, an aluminum oxide film was formed by the ALD method to a thickness of 30 nm to form the first sacrificial layer.

[0503] Next, a tungsten (W) film was formed on the first sacrificial layer by sputtering to a thickness of 54 nm, to form a second sacrificial layer.

[0504] A photoresist was applied onto the second sacrificial layer, and the photoresist was exposed and developed to process the second sacrificial layer so that its edge was positioned inside the edge of the anode. This allows the organic compound layer to be processed into a shape that has an edge inside the edge of the anode.

[0505] Using the photoresist as a mask, the second sacrificial layer was processed using an etching gas containing SF6, and using the second sacrificial layer as a hard mask, the first sacrificial layer was processed using an etching gas containing fluoroform (CHF3), helium (He), and methane (CH4) with a flow rate ratio of CHF3:He:CH4 = 16.5:118.5:15. After this, the organic compound layer was processed using an etching gas containing oxygen (O2).

[0506] The above is the method of processing using the photolithography method. By performing processing using the photolithography method, the hole injection layer, the first hole transport layer, the first light emitting layer, the first electron transport layer, the intermediate layer, the second hole transport layer, the second light emitting layer, and the second electron transport layer of the light emitting device 7B were formed. In addition, the anodes of the parts forming the light emitting device 7R and the light emitting device 7G were exposed.

[0507] Next, a hole injection layer was formed on the second sacrificial layer and the anode in the same manner as in the fabrication method of light-emitting device 4A.

[0508] On the hole injection layer, PCBBiF was evaporated to a thickness of 42.5 nm to form a first hole transport layer.

[0509] On the first hole transport layer, 8mpTP-4mDBtPBfpm-d 13、 βNCCP, Ir(5m4dppy-d3)3) in a weight ratio of 0.5:0.5:0.1 (=8mpTP-4mDBtPBfpm-d 13 A first light-emitting layer was formed by co-evaporation of 40 nm of:βNCCP:Ir(5m4dppy-d3)3).

[0510] Next, a first electron transport layer, and a first layer, a third layer, and a second layer of the intermediate layer were formed in the same manner as in the fabrication of light-emitting device 7B.

[0511] On the intermediate layer, PCBBiF was evaporated to a thickness of 55 nm to form a second hole transport layer, and then a second light-emitting layer was formed in the same manner as the first light-emitting layer.

[0512] Next, a second electron transport layer was formed in the same manner as in the fabrication of light-emitting device 7B.

[0513] Thereafter, the hole injection layer, the first hole transport layer, the first light emitting layer, the first electron transport layer, the intermediate layer, the second hole transport layer, the second light emitting layer, and the second electron transport layer of the light emitting device 7G were formed in the same manner as in the processing method using the photolithography method described above. Also, the anode of the portion where the light emitting device 7R was to be formed was exposed.

[0514] Subsequently, a hole injection layer was formed on the second sacrificial layer and the anode in the same manner as in the fabrication method of the light-emitting device 4A.

[0515] On the hole injection layer, PCBBiF was evaporated to a thickness of 57.5 nm to form a first hole transport layer.

[0516] Next, a first light-emitting layer was formed in the same manner as in the fabrication of light-emitting device 4A, which is a red light-emitting device, and then a first electron transport layer and a first layer, a third layer, and a second layer of the intermediate layer were formed in the same manner as in the fabrication of light-emitting device 7B.

[0517] On the intermediate layer, PCBBiF was deposited to a thickness of 65 nm to form a second hole transport layer, and then a second light-emitting layer was formed in the same manner as the first light-emitting layer.

[0518] Next, a second electron transport layer was formed in the same manner as in the fabrication method of light-emitting device 4A, and then a hole injection layer, a first hole transport layer, a first light-emitting layer, a first electron transport layer, an intermediate layer, a second hole transport layer, a second light-emitting layer, and a second electron transport layer of light-emitting device 7R were formed in the same manner as in the processing method using photolithography described above.

[0519] After forming the hole injection layer, the first and second hole transport layers, the first and second light emitting layers, and the first and second electron transport layers of the light emitting device 7R, the second sacrificial layer was removed using an etching gas containing SF6, leaving the first sacrificial layer. Then, an aluminum oxide film was formed by the ALD method to a thickness of 15 nm to form a protective film.

[0520] Next, a photosensitive polymer material was formed on the protective film using photolithography, without overlapping with the anode. After that, it was heated at 100°C in an air atmosphere for 1 hour, and then unnecessary parts of the first sacrificial layer and protective film were removed using a mixed acid solution containing hydrofluoric acid (HF) to expose the second electron transport layer. At this time, the photosensitive polymer material functions as a resist.

[0521] The substrate with the second electron transport layer exposed was then immersed in 1×10-4 The mixture was introduced into a vacuum deposition apparatus whose inside had been reduced in pressure to about Pa, and vacuum baking was carried out at 100° C. for 90 minutes in a heating chamber in the vacuum deposition apparatus.

[0522] Next, lithium fluoride and ytterbium were co-deposited at a volume ratio of 1:0.5 (=LiF:Yb) to form an electron injection layer of 1.5 nm, and then silver (Ag) and magnesium (Mg) were co-deposited at a volume ratio of 1:0.1 and a film thickness of 15 nm to form a cathode, thereby producing light-emitting device 7R, light-emitting device 7G, and light-emitting device 7B. In addition, a film of PCBBiF was formed as a cap layer on the cathode of each light-emitting device by sputtering to a thickness of 80 nm.

[0523] Table 9 shows the device structures of light-emitting device 7R, light-emitting device 7G, and light-emitting device 7B.

[0524] [Table 9]

[0525] Each of the light-emitting devices thus fabricated was placed in a glove box with a nitrogen atmosphere and sealed with a glass substrate to prevent the light-emitting device from being exposed to the atmosphere (a UV-curable sealant was applied around the element, UV was irradiated only onto the sealant without irradiating the light onto the light-emitting device, and heat-treated at 80°C for 1 hour under atmospheric pressure). The initial characteristics of each light-emitting device were then measured.

[0526] The current efficiency-luminance characteristics of the light-emitting device 4A and the light-emitting device 4B are shown in Fig. 35. Furthermore, the blue index-luminance characteristics of the light-emitting device 6A and the light-emitting device 6B are shown in Fig. 37.

[0527] The luminance of the light-emitting device 4A and the light-emitting device 4B is 1000 cd / m 2 The main characteristics of the light-emitting device 5A and the light-emitting device 5B in the vicinity of the luminance of 1000 cd / m are shown in Table 10. 2The main characteristics of the light-emitting device 6A and the light-emitting device 6B in the vicinity of 1000 cd / m are shown in Table 11. 2 The main characteristics in the vicinity are shown in Table 12. The luminance, CIE chromaticity, and electroluminescence spectrum were measured using a spectroradiometer (SR-UL1R, manufactured by Topcon Corporation) at room temperature.

[0528] [Table 10]

[0529] [Table 11]

[0530] [Table 12]

[0531] 35 and Table 10, the current efficiency of light-emitting device 4B was higher than that of light-emitting device 4A. This shows that, in the tandem red light-emitting device as well, a cathode thickness of 25 nm increases the luminous efficiency, as in the single light-emitting device.

[0532] 36 and Table 11, the current efficiency of light-emitting device 5A was higher than that of light-emitting device 5B. This shows that in a tandem green light-emitting device, a cathode film thickness of 15 nm increases the luminous efficiency.

[0533] 37 and Table 12, the blue index of the light-emitting device 6A was higher than the blue index of the light-emitting device 6B. This shows that, in the tandem type blue light-emitting device as well, the luminous efficiency is improved when the cathode film thickness is 15 nm, as in the single type.

[0534] From the above results, it was found that, in the display device of one embodiment of the present invention, the thickness of the auxiliary electrode 106 is made different for each light-emitting device that emits different light, more specifically, the thickness of the auxiliary electrode 106R of the red light-emitting device 130R is made thicker than the thickness of the auxiliary electrode 106G of the green light-emitting device 130G and the thickness of the auxiliary electrode 106B of the blue light-emitting device 130B, as shown in FIG. 1B. This makes it possible to make the cathode thickness different for each light-emitting device, thereby improving the light-emitting efficiency of each light-emitting device. In addition, in the display device of one embodiment of the present invention, the auxiliary electrode 106R is provided in the red light-emitting device 130R, and the auxiliary electrodes are not provided in the green light-emitting device 130G and the blue light-emitting device 130B, thereby making it possible to make the cathode thickness different for each light-emitting device, thereby improving the light-emitting efficiency of each light-emitting device.

[0535] Next, the current density-voltage characteristics of light-emitting device 7R are shown in Fig. 38, and the external quantum efficiency-current density characteristics are shown in Fig. 39. Furthermore, the current density-voltage characteristics of light-emitting device 7G are shown in Fig. 40, and the external quantum efficiency-current density characteristics are shown in Fig. 41. Furthermore, the current density-voltage characteristics of light-emitting device 7B are shown in Fig. 42, and the external quantum efficiency-current density characteristics are shown in Fig. 43.

[0536] 38 and 39 also show the measurement results of a comparative light-emitting device (represented as Ref. in the figures) that has a similar configuration to the light-emitting device 7R and was fabricated without going through the process of forming an organic compound layer by photolithography. Also, Figs. 40 and 41 also show the measurement results of a comparative light-emitting device (represented as Ref. in the figures) that has a similar configuration to the light-emitting device 7G and was fabricated without going through the process of forming an organic compound layer by photolithography. Also, Figs. 42 and 43 also show the measurement results of a comparative light-emitting device (represented as Ref. in the figures) that has a similar configuration to the light-emitting device 7B and was fabricated without going through the process of forming an organic compound layer by photolithography.

[0537] Fig. 44 shows the results of applying a current to light-emitting device 7R and driving it at a constant current. Fig. 45 shows the results of applying a current to light-emitting device 7G and driving it at a constant current. Fig. 46 shows the results of applying a current to light-emitting device 7B and driving it at a constant current.

[0538] From Figure 44, the current density is set to 63mA / cm 2 As shown in FIG. 45, the LT95 of the light-emitting device 7R is 590 hours when the current density is 54 mA / cm 2 As shown in Figure 46, when the current density is set to 50 mA / cm, the LT95 of the light-emitting device 7G is 200 hours. 2 As a result, the LT95 of the light-emitting device 7B was found to be 204 hours.

[0539] As described above, the light-emitting device 7R has an organic compound layer with the same configuration as the light-emitting device 4A described above, except for the configurations of the intermediate layer and the first electron transport layer. As shown in Fig. 35, the light-emitting device 4A, which has a cathode film thickness of 15 nm, had a lower current efficiency than the light-emitting device 4B, which has a cathode film thickness of 25 nm. Therefore, in the configuration of the light-emitting device 7R, by providing an auxiliary electrode between the electron injection layer and the cathode and fabricating the cathode film thickness to be 25 nm, it is expected that the light-emitting efficiency will be further improved.

[0540] Similarly, the light-emitting device 7G is a green light-emitting device having a cathode of the same thickness (15 nm) as the light-emitting device 5A. As shown in Fig. 36, the light-emitting device 5A, which has a cathode thickness of 15 nm, has a higher current efficiency than the light-emitting device 5B, which has a cathode thickness of 25 nm. Therefore, it is considered preferable not to provide an auxiliary electrode in the light-emitting device 7G in order to maintain high light-emitting efficiency.

[0541] Moreover, the light-emitting device 7B has an organic compound layer with a similar configuration and a cathode with the same thickness (15 nm) as the above-mentioned light-emitting device 6A, except for the difference in the configuration of the intermediate layer, the difference in the thickness of the first hole transport layer, and the difference in the configuration of the first electron transport layer. As shown in Fig. 37, the light-emitting device 6A, which has a cathode thickness of 15 nm, has a higher blue index than the light-emitting device 6B, which has a cathode thickness of 25 nm. Therefore, it is expected that it is preferable not to provide an auxiliary electrode in the light-emitting device 7B in order to maintain high luminous efficiency. [Explanation of symbols]

[0542] 100A display device 100B display device 100D display device 100 display device 101a first electrode 101B First electrode 101b First electrode 101G First electrode 101R First electrode 101 First electrode 102 Second electrode 103a EL layer 103B EL layer 103b EL layer 103Bf Organic compound film 103G EL layer 103Gf organic compound film 103R EL layer 103Rf Organic compound film 103 EL layer 104a EL layer 104B EL layer 104b EL layer 104G EL layer 104R EL layer 104 EL layer 106 Auxiliary electrode 106Rf conductive film 106R Auxiliary electrode 106Gf Conductive Film 106G auxiliary electrode 106B Auxiliary electrode 110B subpixel 110G subpixel 110R subpixel 110 subpixels 111a Hole injection layer 111b Hole injection layer 111 Hole injection layer 112a Hole transport layer 112b Hole transport layer 112 Hole transport layer 113a Light-emitting layer 113b Light-emitting layer 113 Light-emitting layer 114a Electron transport layer 114b Electron transport layer 114 Electron transport layer 115 Electron injection layer 116 Charge generation layer 117 P type layer 118 Electronic Relay Layer 119 Electron injection buffer layer 120 Substrate 122 Resin layer 125a Second insulating layer 125af Insulating film 125b Third insulating layer 127a first insulating layer 127f Insulating film 127 First insulating layer 128 layers 130a Light emitting device 130B Light Emitting Device 130b Light emitting device 130G Light Emitting Device 130R Light Emitting Device 130 Light Emitting Devices 131 Protective layer 132B Colored layer 132G colored layer 132R colored layer 140 Connection 141 areas 142 Adhesive layer 151B Conductive layer 151C conductive layer 151f Conductive film 151G conductive layer 151R conductive layer 151 Conductive layer 152B Conductive layer 152C conductive layer 152f Conductive film 152G Conductive layer 152R Conductive layer 152 Conductive layer 155 Common electrode 156B Insulating layer 156C Insulating layer 156f Insulating film 156G Insulation layer 156R Insulation layer 157 Light blocking layer 158B Protective layer 158Bf Protective film 158G protection layer 158Gf protective film 158R protective layer 158Rf Protective film 159B Sacrificial Layer 159Bf Sacrificial membrane 159G Sacrificial Layer 159Gf Sacrificial film 159R Sacrificial Layer 159Rf Sacrificial film 166 Conductive Layer 171 Insulating Layer 172 Conductive Layer 173 Insulating Layer 174 Insulating Layer 175 Insulating Layer 176 Plug 177 Pixel section 178 pixels 179 Conductive Layer 190B Resist mask 190G Resist Mask 190R Resist Mask 191 Resist Mask 201 Transistor 204 Connection 205 Transistor 211 Insulating layer 213 Insulating Layer 214 Insulating layer 215 Insulating Layer 221 Conductive Layer 222a conductive layer 222b Conductive layer 223 Conductive Layer 224B Conductive layer 224C conductive layer 224G conductive layer 224R conductive layer 231 Semiconductor Layer 240 capacity 241 Conductive Layer 242 Connection Layer 243 Insulating Layer 245 Conductive Layer 254 Insulating layer 255 Insulation Layer 256 Plug 261 Insulating Layer 271 Plug 280 Display Module 281 Display section 282 Circuit section 283a Pixel circuit 283 Pixel circuit section 284a pixels 284 Pixel section 285 Terminal section 286 Wiring section 290 FPC 291 Substrate 292 Substrate 301 Substrate 310 Transistor 311 Conductive layer 312 Low resistance region 313 Insulating Layer 314 Insulating layer 315 Element Isolation Layer 351 Substrate 352 Substrate 353 FPC 354 IC 355 Wiring 356 circuits 501 First electrode 502 Second electrode 511 First Light Emitting Unit 512 Second Light Emitting Unit 513 Charge generation layer 700A electronic equipment 700B Electronic equipment 721 Case 723 Mounting Part 727 Earphones 750 Earphones 751 Display Panel 753 Optical Components 756 Display area 757 Frames 758 Nose pad 800A electronic equipment 800B Electronic equipment 820 Display section 821 Case 822 Communications Department 823 Mounting part 824 Control Unit 825 Imaging unit 827 Earphones 832 Lens 6500 Electronic equipment 6501 Case 6502 Display section 6503 Power button 6504 Button 6505 Speaker 6506 Microphone 6507 Camera 6508 Light source 6510 Protective materials 6511 Display Panel 6512 Optical components 6513 Touch Sensor Panel 6515 FPC 6516 IC 6517 Printed Circuit Board 6518 Battery 7000 Display 7100 Television equipment 7151 Remote control device 7171 Case 7173 Stand 7200 Notebook Personal Computer 7211 Case 7212 Keyboard 7213 Pointing Device 7214 External connection port 7300 Digital Signage 7301 Case 7303 Speaker 7311 Information terminal 7400 Digital Signage 7401 Pillar 7411 Information terminal 9000 Chassis 9001 Display section 9002 Camera 9003 Speaker 9005 Operation key 9006 Connection terminal 9007 Sensor 9008 Microphone 9050 Icon 9051 Information 9052 Information 9053 Information 9054 Information 9055 Hinge 9171 Mobile Information Terminal 9172 Mobile Information Terminal 9173 Tablet PC 9200 Mobile Information Terminal 9201 Mobile information terminals

Claims

1. a first light emitting device and a second light emitting device; the first light-emitting device and the second light-emitting device have a common electrode having light-transmitting properties; The first light emitting device has a first electrode, a first EL layer, and a first auxiliary electrode having light transmitting properties; The second light emitting device has a second electrode, a second EL layer, and a second auxiliary electrode having light transmitting properties; the first EL layer is located between the first electrode and the common electrode; the second EL layer is located between the second electrode and the common electrode; the first auxiliary electrode is located between the first EL layer and the common electrode; the second auxiliary electrode is located between the second EL layer and the common electrode; A display device, wherein the first auxiliary electrode has a thickness greater than a thickness of the second auxiliary electrode.

2. a first light emitting device and a second light emitting device; the first light-emitting device and the second light-emitting device have a common electrode having light-transmitting properties; The first light emitting device has a first electrode, a first EL layer, and a first auxiliary electrode having light transmitting properties; the second light emitting device has a second electrode and a second EL layer; the first EL layer is located between the first electrode and the common electrode; the second EL layer is located between the second electrode and the common electrode and in contact with the common electrode; The first auxiliary electrode is located between the first EL layer and the common electrode.

3. a first light emitting device and a second light emitting device; the first light emitting device and the second light emitting device have a common layer and a light-transmitting common electrode; the common electrode is located on the common layer; The first light emitting device has a first electrode, a first EL layer, and a first auxiliary electrode having light transmitting properties; the second light emitting device has a second electrode and a second EL layer; the first EL layer is located between the first electrode and the common layer; the second EL layer is located between the second electrode and the common layer and in contact with the common layer; The first auxiliary electrode is located between the first EL layer and the common layer.

4. In claim 3, The common layer comprises an alkali metal or an alkaline earth metal.

5. In any one of claims 1 to 4, A display device, wherein the emission color of the first light emitting device is different from the emission color of the second light emitting device.

6. In any one of claims 1 to 4, A display device, wherein light emitted by the first light-emitting device has a longer wavelength than light emitted by the second light-emitting device.

7. In any one of claims 1 to 4, The display device, wherein the first auxiliary electrode comprises silver and magnesium.

8. In claim 7, The display device, wherein the first auxiliary electrode has a film thickness of 1 nm or more and 50 nm or less.

9. In any one of claims 1 to 4, An insulating layer is provided. The insulating layer is located between the first EL layer and the second EL layer.

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